Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

160 files changed, 14816 insertions, 0 deletions

diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
new file mode 100644
index 000000000..7bf0a617e
--- /dev/null
+++ b/arch/csky/Kconfig
@@ -0,0 +1,312 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config CSKY
+	def_bool y
+	select ARCH_32BIT_OFF_T
+	select ARCH_HAS_DMA_PREP_COHERENT
+	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_SYNC_DMA_FOR_CPU
+	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+	select ARCH_USE_BUILTIN_BSWAP
+	select ARCH_USE_QUEUED_RWLOCKS if NR_CPUS>2
+	select ARCH_WANT_FRAME_POINTERS if !CPU_CK610
+	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
+	select COMMON_CLK
+	select CLKSRC_MMIO
+	select CSKY_MPINTC if CPU_CK860
+	select CSKY_MP_TIMER if CPU_CK860
+	select CSKY_APB_INTC
+	select DMA_DIRECT_REMAP
+	select IRQ_DOMAIN
+	select HANDLE_DOMAIN_IRQ
+	select DW_APB_TIMER_OF
+	select GENERIC_IOREMAP
+	select GENERIC_LIB_ASHLDI3
+	select GENERIC_LIB_ASHRDI3
+	select GENERIC_LIB_LSHRDI3
+	select GENERIC_LIB_MULDI3
+	select GENERIC_LIB_CMPDI2
+	select GENERIC_LIB_UCMPDI2
+	select GENERIC_ALLOCATOR
+	select GENERIC_ATOMIC64
+	select GENERIC_CLOCKEVENTS
+	select GENERIC_CPU_DEVICES
+	select GENERIC_IRQ_CHIP
+	select GENERIC_IRQ_PROBE
+	select GENERIC_IRQ_SHOW
+	select GENERIC_IRQ_MULTI_HANDLER
+	select GENERIC_SCHED_CLOCK
+	select GENERIC_SMP_IDLE_THREAD
+	select GX6605S_TIMER if CPU_CK610
+	select HAVE_ARCH_TRACEHOOK
+	select HAVE_ARCH_AUDITSYSCALL
+	select HAVE_ARCH_MMAP_RND_BITS
+	select HAVE_ARCH_SECCOMP_FILTER
+	select HAVE_CONTEXT_TRACKING
+	select HAVE_VIRT_CPU_ACCOUNTING_GEN
+	select HAVE_DEBUG_BUGVERBOSE
+	select HAVE_DYNAMIC_FTRACE
+	select HAVE_DYNAMIC_FTRACE_WITH_REGS
+	select HAVE_FUNCTION_TRACER
+	select HAVE_FUNCTION_GRAPH_TRACER
+	select HAVE_FUNCTION_ERROR_INJECTION
+	select HAVE_FTRACE_MCOUNT_RECORD
+	select HAVE_KERNEL_GZIP
+	select HAVE_KERNEL_LZO
+	select HAVE_KERNEL_LZMA
+	select HAVE_KPROBES if !CPU_CK610
+	select HAVE_KPROBES_ON_FTRACE if !CPU_CK610
+	select HAVE_KRETPROBES if !CPU_CK610
+	select HAVE_PERF_EVENTS
+	select HAVE_PERF_REGS
+	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_DMA_CONTIGUOUS
+	select HAVE_REGS_AND_STACK_ACCESS_API
+	select HAVE_RSEQ
+	select HAVE_STACKPROTECTOR
+	select HAVE_SYSCALL_TRACEPOINTS
+	select MAY_HAVE_SPARSE_IRQ
+	select MODULES_USE_ELF_RELA if MODULES
+	select OF
+	select OF_EARLY_FLATTREE
+	select PERF_USE_VMALLOC if CPU_CK610
+	select RTC_LIB
+	select TIMER_OF
+	select USB_ARCH_HAS_EHCI
+	select USB_ARCH_HAS_OHCI
+	select GENERIC_PCI_IOMAP
+	select HAVE_PCI
+	select PCI_DOMAINS_GENERIC if PCI
+	select PCI_SYSCALL if PCI
+	select PCI_MSI if PCI
+	select SET_FS
+
+config LOCKDEP_SUPPORT
+	def_bool y
+
+config ARCH_SUPPORTS_UPROBES
+	def_bool y if !CPU_CK610
+
+config CPU_HAS_CACHEV2
+	bool
+
+config CPU_HAS_FPUV2
+	bool
+
+config CPU_HAS_HILO
+	bool
+
+config CPU_HAS_TLBI
+	bool
+
+config CPU_HAS_LDSTEX
+	bool
+	help
+	  For SMP, CPU needs "ldex&stex" instructions for atomic operations.
+
+config CPU_NEED_TLBSYNC
+	bool
+
+config CPU_NEED_SOFTALIGN
+	bool
+
+config CPU_NO_USER_BKPT
+	bool
+	help
+	  For abiv2 we couldn't use "trap 1" as user space bkpt in gdbserver, because
+	  abiv2 is 16/32bit instruction set and "trap 1" is 32bit.
+	  So we need a 16bit instruction as user space bkpt, and it will cause an illegal
+	  instruction exception.
+	  In kernel we parse the *regs->pc to determine whether to send SIGTRAP or not.
+
+config GENERIC_CALIBRATE_DELAY
+	def_bool y
+
+config GENERIC_CSUM
+	def_bool y
+
+config GENERIC_HWEIGHT
+	def_bool y
+
+config MMU
+	def_bool y
+
+config STACKTRACE_SUPPORT
+	def_bool y
+
+config TIME_LOW_RES
+	def_bool y
+
+config TRACE_IRQFLAGS_SUPPORT
+	def_bool y
+
+config CPU_TLB_SIZE
+	int
+	default "128"	if (CPU_CK610 || CPU_CK807 || CPU_CK810)
+	default "1024"	if (CPU_CK860)
+
+config CPU_ASID_BITS
+	int
+	default "8"	if (CPU_CK610 || CPU_CK807 || CPU_CK810)
+	default "12"	if (CPU_CK860)
+
+config L1_CACHE_SHIFT
+	int
+	default "4"	if (CPU_CK610)
+	default "5"	if (CPU_CK807 || CPU_CK810)
+	default "6"	if (CPU_CK860)
+
+config ARCH_MMAP_RND_BITS_MIN
+	default 8
+
+# max bits determined by the following formula:
+#  VA_BITS - PAGE_SHIFT - 3
+config ARCH_MMAP_RND_BITS_MAX
+	default 17
+
+menu "Processor type and features"
+
+choice
+	prompt "CPU MODEL"
+	default CPU_CK807
+
+config CPU_CK610
+	bool "CSKY CPU ck610"
+	select CPU_NEED_TLBSYNC
+	select CPU_NEED_SOFTALIGN
+	select CPU_NO_USER_BKPT
+
+config CPU_CK810
+	bool "CSKY CPU ck810"
+	select CPU_HAS_HILO
+	select CPU_NEED_TLBSYNC
+
+config CPU_CK807
+	bool "CSKY CPU ck807"
+	select CPU_HAS_HILO
+
+config CPU_CK860
+	bool "CSKY CPU ck860"
+	select CPU_HAS_TLBI
+	select CPU_HAS_CACHEV2
+	select CPU_HAS_LDSTEX
+	select CPU_HAS_FPUV2
+endchoice
+
+choice
+	prompt "C-SKY PMU type"
+	depends on PERF_EVENTS
+	depends on CPU_CK807 || CPU_CK810 || CPU_CK860
+
+config CPU_PMU_NONE
+	bool "None"
+
+config CSKY_PMU_V1
+	bool "Performance Monitoring Unit Ver.1"
+
+endchoice
+
+choice
+	prompt "Power Manager Instruction (wait/doze/stop)"
+	default CPU_PM_NONE
+
+config CPU_PM_NONE
+	bool "None"
+
+config CPU_PM_WAIT
+	bool "wait"
+
+config CPU_PM_DOZE
+	bool "doze"
+
+config CPU_PM_STOP
+	bool "stop"
+endchoice
+
+menuconfig HAVE_TCM
+	bool "Tightly-Coupled/Sram Memory"
+	select GENERIC_ALLOCATOR
+	help
+	  The implementation are not only used by TCM (Tightly-Coupled Meory)
+	  but also used by sram on SOC bus. It follow existed linux tcm
+	  software interface, so that old tcm application codes could be
+	  re-used directly.
+
+if HAVE_TCM
+config ITCM_RAM_BASE
+	hex "ITCM ram base"
+	default 0xffffffff
+
+config ITCM_NR_PAGES
+	int "Page count of ITCM size: NR*4KB"
+	range 1 256
+	default 32
+
+config HAVE_DTCM
+	bool "DTCM Support"
+
+config DTCM_RAM_BASE
+	hex "DTCM ram base"
+	depends on HAVE_DTCM
+	default 0xffffffff
+
+config DTCM_NR_PAGES
+	int "Page count of DTCM size: NR*4KB"
+	depends on HAVE_DTCM
+	range 1 256
+	default 32
+endif
+
+config CPU_HAS_VDSP
+	bool "CPU has VDSP coprocessor"
+	depends on CPU_HAS_FPU && CPU_HAS_FPUV2
+
+config CPU_HAS_FPU
+	bool "CPU has FPU coprocessor"
+	depends on CPU_CK807 || CPU_CK810 || CPU_CK860
+
+config CPU_HAS_ICACHE_INS
+	bool "CPU has Icache invalidate instructions"
+	depends on CPU_HAS_CACHEV2
+
+config CPU_HAS_TEE
+	bool "CPU has Trusted Execution Environment"
+	depends on CPU_CK810
+
+config SMP
+	bool "Symmetric Multi-Processing (SMP) support for C-SKY"
+	depends on CPU_CK860
+	default n
+
+config NR_CPUS
+	int "Maximum number of CPUs (2-32)"
+	range 2 32
+	depends on SMP
+	default "4"
+
+config HIGHMEM
+	bool "High Memory Support"
+	depends on !CPU_CK610
+	default y
+
+config FORCE_MAX_ZONEORDER
+	int "Maximum zone order"
+	default "11"
+
+config DRAM_BASE
+	hex "DRAM start addr (the same with memory-section in dts)"
+	default 0x0
+
+config HOTPLUG_CPU
+	bool "Support for hot-pluggable CPUs"
+	select GENERIC_IRQ_MIGRATION
+	depends on SMP
+	help
+	  Say Y here to allow turning CPUs off and on. CPUs can be
+	  controlled through /sys/devices/system/cpu/cpu1/hotplug/target.
+
+	  Say N if you want to disable CPU hotplug.
+endmenu
+
+source "arch/csky/Kconfig.platforms"
+
+source "kernel/Kconfig.hz"
diff --git a/arch/csky/Kconfig.debug b/arch/csky/Kconfig.debug
new file mode 100644
index 000000000..295942fe3
--- /dev/null
+++ b/arch/csky/Kconfig.debug
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# dummy file, do not delete
diff --git a/arch/csky/Kconfig.platforms b/arch/csky/Kconfig.platforms
new file mode 100644
index 000000000..639e17f4e
--- /dev/null
+++ b/arch/csky/Kconfig.platforms
@@ -0,0 +1,9 @@
+menu "Platform drivers selection"
+
+config ARCH_CSKY_DW_APB_ICTL
+	bool "Select dw-apb interrupt controller"
+	select DW_APB_ICTL
+	default y
+	help
+	  This enables support for snps dw-apb-ictl
+endmenu
diff --git a/arch/csky/Makefile b/arch/csky/Makefile
new file mode 100644
index 000000000..37f593a4b
--- /dev/null
+++ b/arch/csky/Makefile
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: GPL-2.0-only
+OBJCOPYFLAGS		:=-O binary
+GZFLAGS			:=-9
+
+ifdef CONFIG_CPU_HAS_FPU
+FPUEXT = f
+endif
+
+ifdef CONFIG_CPU_HAS_VDSP
+VDSPEXT = v
+endif
+
+ifdef CONFIG_CPU_HAS_TEE
+TEEEXT = t
+endif
+
+ifdef CONFIG_CPU_CK610
+CPUTYPE	= ck610
+CSKYABI	= abiv1
+endif
+
+ifdef CONFIG_CPU_CK810
+CPUTYPE = ck810
+CSKYABI	= abiv2
+endif
+
+ifdef CONFIG_CPU_CK807
+CPUTYPE = ck807
+CSKYABI	= abiv2
+endif
+
+ifdef CONFIG_CPU_CK860
+CPUTYPE = ck860
+CSKYABI	= abiv2
+endif
+
+ifneq ($(CSKYABI),)
+MCPU_STR = $(CPUTYPE)$(FPUEXT)$(VDSPEXT)$(TEEEXT)
+KBUILD_CFLAGS += -mcpu=$(CPUTYPE) -Wa,-mcpu=$(MCPU_STR)
+KBUILD_CFLAGS += -DCSKYCPU_DEF_NAME=\"$(MCPU_STR)\"
+KBUILD_CFLAGS += -msoft-float -mdiv
+KBUILD_CFLAGS += -fno-tree-vectorize
+endif
+
+KBUILD_CFLAGS += -pipe
+ifeq ($(CSKYABI),abiv2)
+KBUILD_CFLAGS += -mno-stack-size
+endif
+
+ifdef CONFIG_FRAME_POINTER
+KBUILD_CFLAGS += -mbacktrace
+endif
+
+abidirs := $(patsubst %,arch/csky/%/,$(CSKYABI))
+KBUILD_CFLAGS += $(patsubst %,-I$(srctree)/%inc,$(abidirs))
+
+KBUILD_CPPFLAGS += -mlittle-endian
+LDFLAGS += -EL
+
+KBUILD_AFLAGS += $(KBUILD_CFLAGS)
+
+head-y := arch/csky/kernel/head.o
+
+core-y += arch/csky/kernel/
+core-y += arch/csky/mm/
+core-y += arch/csky/$(CSKYABI)/
+
+libs-y += arch/csky/lib/ \
+	$(shell $(CC) $(KBUILD_CFLAGS) $(KCFLAGS) -print-libgcc-file-name)
+
+boot := arch/csky/boot
+core-y += $(boot)/dts/
+
+all: zImage
+
+zImage Image uImage: vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
+
+archclean:
+	$(Q)$(MAKE) $(clean)=$(boot)
+
+define archhelp
+  echo  '* zImage       - Compressed kernel image (arch/$(ARCH)/boot/zImage)'
+  echo  '  Image        - Uncompressed kernel image (arch/$(ARCH)/boot/Image)'
+  echo  '  uImage       - U-Boot wrapped zImage'
+endef
diff --git a/arch/csky/abiv1/Makefile b/arch/csky/abiv1/Makefile
new file mode 100644
index 000000000..601ce3b2f
--- /dev/null
+++ b/arch/csky/abiv1/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_CPU_NEED_SOFTALIGN)	+= alignment.o
+obj-y					+= bswapdi.o
+obj-y					+= bswapsi.o
+obj-y					+= cacheflush.o
+obj-y					+= mmap.o
+obj-y					+= memcpy.o
+obj-y					+= strksyms.o
diff --git a/arch/csky/abiv1/alignment.c b/arch/csky/abiv1/alignment.c
new file mode 100644
index 000000000..2df115d0e
--- /dev/null
+++ b/arch/csky/abiv1/alignment.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/kernel.h>
+#include <linux/uaccess.h>
+#include <linux/ptrace.h>
+
+static int align_kern_enable = 1;
+static int align_usr_enable = 1;
+static int align_kern_count = 0;
+static int align_usr_count = 0;
+
+static inline uint32_t get_ptreg(struct pt_regs *regs, uint32_t rx)
+{
+	return rx == 15 ? regs->lr : *((uint32_t *)&(regs->a0) - 2 + rx);
+}
+
+static inline void put_ptreg(struct pt_regs *regs, uint32_t rx, uint32_t val)
+{
+	if (rx == 15)
+		regs->lr = val;
+	else
+		*((uint32_t *)&(regs->a0) - 2 + rx) = val;
+}
+
+/*
+ * Get byte-value from addr and set it to *valp.
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int ldb_asm(uint32_t addr, uint32_t *valp)
+{
+	uint32_t val;
+	int err;
+
+	asm volatile (
+		"movi	%0, 0\n"
+		"1:\n"
+		"ldb	%1, (%2)\n"
+		"br	3f\n"
+		"2:\n"
+		"movi	%0, 1\n"
+		"br	3f\n"
+		".section __ex_table,\"a\"\n"
+		".align 2\n"
+		".long	1b, 2b\n"
+		".previous\n"
+		"3:\n"
+		: "=&r"(err), "=r"(val)
+		: "r" (addr)
+	);
+
+	*valp = val;
+
+	return err;
+}
+
+/*
+ * Put byte-value to addr.
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int stb_asm(uint32_t addr, uint32_t val)
+{
+	int err;
+
+	asm volatile (
+		"movi	%0, 0\n"
+		"1:\n"
+		"stb	%1, (%2)\n"
+		"br	3f\n"
+		"2:\n"
+		"movi	%0, 1\n"
+		"br	3f\n"
+		".section __ex_table,\"a\"\n"
+		".align 2\n"
+		".long	1b, 2b\n"
+		".previous\n"
+		"3:\n"
+		: "=&r"(err)
+		: "r"(val), "r" (addr)
+	);
+
+	return err;
+}
+
+/*
+ * Get half-word from [rx + imm]
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int ldh_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
+{
+	uint32_t byte0, byte1;
+
+	if (ldb_asm(addr, &byte0))
+		return 1;
+	addr += 1;
+	if (ldb_asm(addr, &byte1))
+		return 1;
+
+	byte0 |= byte1 << 8;
+	put_ptreg(regs, rz, byte0);
+
+	return 0;
+}
+
+/*
+ * Store half-word to [rx + imm]
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int sth_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
+{
+	uint32_t byte0, byte1;
+
+	byte0 = byte1 = get_ptreg(regs, rz);
+
+	byte0 &= 0xff;
+
+	if (stb_asm(addr, byte0))
+		return 1;
+
+	addr += 1;
+	byte1 = (byte1 >> 8) & 0xff;
+	if (stb_asm(addr, byte1))
+		return 1;
+
+	return 0;
+}
+
+/*
+ * Get word from [rx + imm]
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int ldw_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
+{
+	uint32_t byte0, byte1, byte2, byte3;
+
+	if (ldb_asm(addr, &byte0))
+		return 1;
+
+	addr += 1;
+	if (ldb_asm(addr, &byte1))
+		return 1;
+
+	addr += 1;
+	if (ldb_asm(addr, &byte2))
+		return 1;
+
+	addr += 1;
+	if (ldb_asm(addr, &byte3))
+		return 1;
+
+	byte0 |= byte1 << 8;
+	byte0 |= byte2 << 16;
+	byte0 |= byte3 << 24;
+
+	put_ptreg(regs, rz, byte0);
+
+	return 0;
+}
+
+/*
+ * Store word to [rx + imm]
+ *
+ * Success: return 0
+ * Failure: return 1
+ */
+static int stw_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
+{
+	uint32_t byte0, byte1, byte2, byte3;
+
+	byte0 = byte1 = byte2 = byte3 = get_ptreg(regs, rz);
+
+	byte0 &= 0xff;
+
+	if (stb_asm(addr, byte0))
+		return 1;
+
+	addr += 1;
+	byte1 = (byte1 >> 8) & 0xff;
+	if (stb_asm(addr, byte1))
+		return 1;
+
+	addr += 1;
+	byte2 = (byte2 >> 16) & 0xff;
+	if (stb_asm(addr, byte2))
+		return 1;
+
+	addr += 1;
+	byte3 = (byte3 >> 24) & 0xff;
+	if (stb_asm(addr, byte3))
+		return 1;
+
+	return 0;
+}
+
+extern int fixup_exception(struct pt_regs *regs);
+
+#define OP_LDH 0xc000
+#define OP_STH 0xd000
+#define OP_LDW 0x8000
+#define OP_STW 0x9000
+
+void csky_alignment(struct pt_regs *regs)
+{
+	int ret;
+	uint16_t tmp;
+	uint32_t opcode = 0;
+	uint32_t rx     = 0;
+	uint32_t rz     = 0;
+	uint32_t imm    = 0;
+	uint32_t addr   = 0;
+
+	if (!user_mode(regs))
+		goto kernel_area;
+
+	if (!align_usr_enable) {
+		pr_err("%s user disabled.\n", __func__);
+		goto bad_area;
+	}
+
+	align_usr_count++;
+
+	ret = get_user(tmp, (uint16_t *)instruction_pointer(regs));
+	if (ret) {
+		pr_err("%s get_user failed.\n", __func__);
+		goto bad_area;
+	}
+
+	goto good_area;
+
+kernel_area:
+	if (!align_kern_enable) {
+		pr_err("%s kernel disabled.\n", __func__);
+		goto bad_area;
+	}
+
+	align_kern_count++;
+
+	tmp = *(uint16_t *)instruction_pointer(regs);
+
+good_area:
+	opcode = (uint32_t)tmp;
+
+	rx  = opcode & 0xf;
+	imm = (opcode >> 4) & 0xf;
+	rz  = (opcode >> 8) & 0xf;
+	opcode &= 0xf000;
+
+	if (rx == 0 || rx == 1 || rz == 0 || rz == 1)
+		goto bad_area;
+
+	switch (opcode) {
+	case OP_LDH:
+		addr = get_ptreg(regs, rx) + (imm << 1);
+		ret = ldh_c(regs, rz, addr);
+		break;
+	case OP_LDW:
+		addr = get_ptreg(regs, rx) + (imm << 2);
+		ret = ldw_c(regs, rz, addr);
+		break;
+	case OP_STH:
+		addr = get_ptreg(regs, rx) + (imm << 1);
+		ret = sth_c(regs, rz, addr);
+		break;
+	case OP_STW:
+		addr = get_ptreg(regs, rx) + (imm << 2);
+		ret = stw_c(regs, rz, addr);
+		break;
+	}
+
+	if (ret)
+		goto bad_area;
+
+	regs->pc += 2;
+
+	return;
+
+bad_area:
+	if (!user_mode(regs)) {
+		if (fixup_exception(regs))
+			return;
+
+		bust_spinlocks(1);
+		pr_alert("%s opcode: %x, rz: %d, rx: %d, imm: %d, addr: %x.\n",
+				__func__, opcode, rz, rx, imm, addr);
+		show_regs(regs);
+		bust_spinlocks(0);
+		make_task_dead(SIGKILL);
+	}
+
+	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)addr);
+}
+
+static struct ctl_table alignment_tbl[5] = {
+	{
+		.procname = "kernel_enable",
+		.data = &align_kern_enable,
+		.maxlen = sizeof(align_kern_enable),
+		.mode = 0666,
+		.proc_handler = &proc_dointvec
+	},
+	{
+		.procname = "user_enable",
+		.data = &align_usr_enable,
+		.maxlen = sizeof(align_usr_enable),
+		.mode = 0666,
+		.proc_handler = &proc_dointvec
+	},
+	{
+		.procname = "kernel_count",
+		.data = &align_kern_count,
+		.maxlen = sizeof(align_kern_count),
+		.mode = 0666,
+		.proc_handler = &proc_dointvec
+	},
+	{
+		.procname = "user_count",
+		.data = &align_usr_count,
+		.maxlen = sizeof(align_usr_count),
+		.mode = 0666,
+		.proc_handler = &proc_dointvec
+	},
+	{}
+};
+
+static struct ctl_table sysctl_table[2] = {
+	{
+	 .procname = "csky_alignment",
+	 .mode = 0555,
+	 .child = alignment_tbl},
+	{}
+};
+
+static struct ctl_path sysctl_path[2] = {
+	{.procname = "csky"},
+	{}
+};
+
+static int __init csky_alignment_init(void)
+{
+	register_sysctl_paths(sysctl_path, sysctl_table);
+	return 0;
+}
+
+arch_initcall(csky_alignment_init);
diff --git a/arch/csky/abiv1/bswapdi.c b/arch/csky/abiv1/bswapdi.c
new file mode 100644
index 000000000..f50a1d6e3
--- /dev/null
+++ b/arch/csky/abiv1/bswapdi.c
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/export.h>
+#include <linux/compiler.h>
+#include <uapi/linux/swab.h>
+
+unsigned long long notrace __bswapdi2(unsigned long long u)
+{
+	return ___constant_swab64(u);
+}
+EXPORT_SYMBOL(__bswapdi2);
diff --git a/arch/csky/abiv1/bswapsi.c b/arch/csky/abiv1/bswapsi.c
new file mode 100644
index 000000000..0f79182e8
--- /dev/null
+++ b/arch/csky/abiv1/bswapsi.c
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/export.h>
+#include <linux/compiler.h>
+#include <uapi/linux/swab.h>
+
+unsigned int notrace __bswapsi2(unsigned int u)
+{
+	return ___constant_swab32(u);
+}
+EXPORT_SYMBOL(__bswapsi2);
diff --git a/arch/csky/abiv1/cacheflush.c b/arch/csky/abiv1/cacheflush.c
new file mode 100644
index 000000000..9f1fe80cc
--- /dev/null
+++ b/arch/csky/abiv1/cacheflush.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/syscalls.h>
+#include <linux/spinlock.h>
+#include <asm/page.h>
+#include <asm/cache.h>
+#include <asm/cacheflush.h>
+#include <asm/cachectl.h>
+
+#define PG_dcache_clean		PG_arch_1
+
+void flush_dcache_page(struct page *page)
+{
+	struct address_space *mapping;
+
+	if (page == ZERO_PAGE(0))
+		return;
+
+	mapping = page_mapping_file(page);
+
+	if (mapping && !page_mapcount(page))
+		clear_bit(PG_dcache_clean, &page->flags);
+	else {
+		dcache_wbinv_all();
+		if (mapping)
+			icache_inv_all();
+		set_bit(PG_dcache_clean, &page->flags);
+	}
+}
+EXPORT_SYMBOL(flush_dcache_page);
+
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr,
+	pte_t *ptep)
+{
+	unsigned long pfn = pte_pfn(*ptep);
+	struct page *page;
+
+	if (!pfn_valid(pfn))
+		return;
+
+	page = pfn_to_page(pfn);
+	if (page == ZERO_PAGE(0))
+		return;
+
+	if (!test_and_set_bit(PG_dcache_clean, &page->flags))
+		dcache_wbinv_all();
+
+	if (page_mapping_file(page)) {
+		if (vma->vm_flags & VM_EXEC)
+			icache_inv_all();
+	}
+}
+
+void flush_kernel_dcache_page(struct page *page)
+{
+	struct address_space *mapping;
+
+	mapping = page_mapping_file(page);
+
+	if (!mapping || mapping_mapped(mapping))
+		dcache_wbinv_all();
+}
+EXPORT_SYMBOL(flush_kernel_dcache_page);
+
+void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
+	unsigned long end)
+{
+	dcache_wbinv_all();
+
+	if (vma->vm_flags & VM_EXEC)
+		icache_inv_all();
+}
diff --git a/arch/csky/abiv1/inc/abi/cacheflush.h b/arch/csky/abiv1/inc/abi/cacheflush.h
new file mode 100644
index 000000000..d3e04208d
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/cacheflush.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ABI_CSKY_CACHEFLUSH_H
+#define __ABI_CSKY_CACHEFLUSH_H
+
+#include <linux/mm.h>
+#include <asm/string.h>
+#include <asm/cache.h>
+
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
+extern void flush_dcache_page(struct page *);
+
+#define flush_cache_mm(mm)			dcache_wbinv_all()
+#define flush_cache_page(vma, page, pfn)	cache_wbinv_all()
+#define flush_cache_dup_mm(mm)			cache_wbinv_all()
+
+#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
+extern void flush_kernel_dcache_page(struct page *);
+
+#define flush_dcache_mmap_lock(mapping)		xa_lock_irq(&mapping->i_pages)
+#define flush_dcache_mmap_unlock(mapping)	xa_unlock_irq(&mapping->i_pages)
+
+static inline void flush_kernel_vmap_range(void *addr, int size)
+{
+	dcache_wbinv_all();
+}
+static inline void invalidate_kernel_vmap_range(void *addr, int size)
+{
+	dcache_wbinv_all();
+}
+
+#define ARCH_HAS_FLUSH_ANON_PAGE
+static inline void flush_anon_page(struct vm_area_struct *vma,
+			 struct page *page, unsigned long vmaddr)
+{
+	if (PageAnon(page))
+		cache_wbinv_all();
+}
+
+/*
+ * if (current_mm != vma->mm) cache_wbinv_range(start, end) will be broken.
+ * Use cache_wbinv_all() here and need to be improved in future.
+ */
+extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
+#define flush_cache_vmap(start, end)		cache_wbinv_all()
+#define flush_cache_vunmap(start, end)		cache_wbinv_all()
+
+#define flush_icache_page(vma, page)		do {} while (0);
+#define flush_icache_range(start, end)		cache_wbinv_range(start, end)
+#define flush_icache_mm_range(mm, start, end)	cache_wbinv_range(start, end)
+#define flush_icache_deferred(mm)		do {} while (0);
+
+#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
+do { \
+	memcpy(dst, src, len); \
+} while (0)
+
+#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
+do { \
+	memcpy(dst, src, len); \
+	cache_wbinv_all(); \
+} while (0)
+
+#endif /* __ABI_CSKY_CACHEFLUSH_H */
diff --git a/arch/csky/abiv1/inc/abi/ckmmu.h b/arch/csky/abiv1/inc/abi/ckmmu.h
new file mode 100644
index 000000000..ba8eb5870
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/ckmmu.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_CKMMUV1_H
+#define __ASM_CSKY_CKMMUV1_H
+#include <abi/reg_ops.h>
+
+static inline int read_mmu_index(void)
+{
+	return cprcr("cpcr0");
+}
+
+static inline void write_mmu_index(int value)
+{
+	cpwcr("cpcr0", value);
+}
+
+static inline int read_mmu_entrylo0(void)
+{
+	return cprcr("cpcr2") << 6;
+}
+
+static inline int read_mmu_entrylo1(void)
+{
+	return cprcr("cpcr3") << 6;
+}
+
+static inline void write_mmu_pagemask(int value)
+{
+	cpwcr("cpcr6", value);
+}
+
+static inline int read_mmu_entryhi(void)
+{
+	return cprcr("cpcr4");
+}
+
+static inline void write_mmu_entryhi(int value)
+{
+	cpwcr("cpcr4", value);
+}
+
+static inline unsigned long read_mmu_msa0(void)
+{
+	return cprcr("cpcr30");
+}
+
+static inline void write_mmu_msa0(unsigned long value)
+{
+	cpwcr("cpcr30", value);
+}
+
+static inline unsigned long read_mmu_msa1(void)
+{
+	return cprcr("cpcr31");
+}
+
+static inline void write_mmu_msa1(unsigned long value)
+{
+	cpwcr("cpcr31", value);
+}
+
+/*
+ * TLB operations.
+ */
+static inline void tlb_probe(void)
+{
+	cpwcr("cpcr8", 0x80000000);
+}
+
+static inline void tlb_read(void)
+{
+	cpwcr("cpcr8", 0x40000000);
+}
+
+static inline void tlb_invalid_all(void)
+{
+	cpwcr("cpcr8", 0x04000000);
+}
+
+
+static inline void local_tlb_invalid_all(void)
+{
+	tlb_invalid_all();
+}
+
+static inline void tlb_invalid_indexed(void)
+{
+	cpwcr("cpcr8", 0x02000000);
+}
+
+static inline void setup_pgd(unsigned long pgd, bool kernel)
+{
+	cpwcr("cpcr29", pgd | BIT(0));
+}
+
+static inline unsigned long get_pgd(void)
+{
+	return cprcr("cpcr29") & ~BIT(0);
+}
+#endif /* __ASM_CSKY_CKMMUV1_H */
diff --git a/arch/csky/abiv1/inc/abi/elf.h b/arch/csky/abiv1/inc/abi/elf.h
new file mode 100644
index 000000000..3058cc06b
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/elf.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ABI_CSKY_ELF_H
+#define __ABI_CSKY_ELF_H
+
+#define ELF_CORE_COPY_REGS(pr_reg, regs) do {	\
+	pr_reg[0] = regs->pc;			\
+	pr_reg[1] = regs->regs[9];		\
+	pr_reg[2] = regs->usp;			\
+	pr_reg[3] = regs->sr;			\
+	pr_reg[4] = regs->a0;			\
+	pr_reg[5] = regs->a1;			\
+	pr_reg[6] = regs->a2;			\
+	pr_reg[7] = regs->a3;			\
+	pr_reg[8] = regs->regs[0];		\
+	pr_reg[9] = regs->regs[1];		\
+	pr_reg[10] = regs->regs[2];		\
+	pr_reg[11] = regs->regs[3];		\
+	pr_reg[12] = regs->regs[4];		\
+	pr_reg[13] = regs->regs[5];		\
+	pr_reg[14] = regs->regs[6];		\
+	pr_reg[15] = regs->regs[7];		\
+	pr_reg[16] = regs->regs[8];		\
+	pr_reg[17] = regs->lr;			\
+} while (0);
+#endif /* __ABI_CSKY_ELF_H */
diff --git a/arch/csky/abiv1/inc/abi/entry.h b/arch/csky/abiv1/inc/abi/entry.h
new file mode 100644
index 000000000..13c23e2c7
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/entry.h
@@ -0,0 +1,177 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_ENTRY_H
+#define __ASM_CSKY_ENTRY_H
+
+#include <asm/setup.h>
+#include <abi/regdef.h>
+
+#define LSAVE_PC	8
+#define LSAVE_PSR	12
+#define LSAVE_A0	24
+#define LSAVE_A1	28
+#define LSAVE_A2	32
+#define LSAVE_A3	36
+#define LSAVE_A4	40
+#define LSAVE_A5	44
+
+#define usp ss1
+
+.macro USPTOKSP
+	mtcr	sp, usp
+	mfcr	sp, ss0
+.endm
+
+.macro KSPTOUSP
+	mtcr	sp, ss0
+	mfcr	sp, usp
+.endm
+
+.macro	SAVE_ALL epc_inc
+	mtcr    r13, ss2
+	mfcr    r13, epsr
+	btsti   r13, 31
+	bt      1f
+	USPTOKSP
+1:
+	subi    sp, 32
+	subi    sp, 32
+	subi    sp, 16
+	stw     r13, (sp, 12)
+
+	stw     lr, (sp, 4)
+
+	mfcr	lr, epc
+	movi	r13, \epc_inc
+	add	lr, r13
+	stw     lr, (sp, 8)
+
+	mov	lr, sp
+	addi	lr, 32
+	addi	lr, 32
+	addi	lr, 16
+	bt	2f
+	mfcr	lr, ss1
+2:
+	stw     lr, (sp, 16)
+
+	stw     a0, (sp, 20)
+	stw     a0, (sp, 24)
+	stw     a1, (sp, 28)
+	stw     a2, (sp, 32)
+	stw     a3, (sp, 36)
+
+	addi	sp, 32
+	addi	sp, 8
+	mfcr    r13, ss2
+	stw	r6, (sp)
+	stw	r7, (sp, 4)
+	stw	r8, (sp, 8)
+	stw	r9, (sp, 12)
+	stw	r10, (sp, 16)
+	stw	r11, (sp, 20)
+	stw	r12, (sp, 24)
+	stw	r13, (sp, 28)
+	stw	r14, (sp, 32)
+	stw	r1, (sp, 36)
+	subi	sp, 32
+	subi	sp, 8
+.endm
+
+.macro	RESTORE_ALL
+	ldw	lr, (sp, 4)
+	ldw     a0, (sp, 8)
+	mtcr    a0, epc
+	ldw     a0, (sp, 12)
+	mtcr    a0, epsr
+	btsti   a0, 31
+	bt      1f
+	ldw     a0, (sp, 16)
+	mtcr	a0, ss1
+1:
+	ldw     a0, (sp, 24)
+	ldw     a1, (sp, 28)
+	ldw     a2, (sp, 32)
+	ldw     a3, (sp, 36)
+
+	addi	sp, 32
+	addi	sp, 8
+	ldw	r6, (sp)
+	ldw	r7, (sp, 4)
+	ldw	r8, (sp, 8)
+	ldw	r9, (sp, 12)
+	ldw	r10, (sp, 16)
+	ldw	r11, (sp, 20)
+	ldw	r12, (sp, 24)
+	ldw	r13, (sp, 28)
+	ldw	r14, (sp, 32)
+	ldw	r1, (sp, 36)
+	addi	sp, 32
+	addi	sp, 8
+
+	bt      2f
+	KSPTOUSP
+2:
+	rte
+.endm
+
+.macro SAVE_SWITCH_STACK
+	subi    sp, 32
+	stm     r8-r15, (sp)
+.endm
+
+.macro RESTORE_SWITCH_STACK
+	ldm     r8-r15, (sp)
+	addi    sp, 32
+.endm
+
+/* MMU registers operators. */
+.macro RD_MIR	rx
+	cprcr   \rx, cpcr0
+.endm
+
+.macro RD_MEH	rx
+	cprcr   \rx, cpcr4
+.endm
+
+.macro RD_MCIR	rx
+	cprcr   \rx, cpcr8
+.endm
+
+.macro RD_PGDR  rx
+	cprcr   \rx, cpcr29
+.endm
+
+.macro WR_MEH	rx
+	cpwcr   \rx, cpcr4
+.endm
+
+.macro WR_MCIR	rx
+	cpwcr   \rx, cpcr8
+.endm
+
+.macro SETUP_MMU
+	/* Init psr and enable ee */
+	lrw	r6, DEFAULT_PSR_VALUE
+	mtcr    r6, psr
+	psrset  ee
+
+	/* Select MMU as co-processor */
+	cpseti	cp15
+
+	/*
+	 * cpcr30 format:
+	 * 31 - 29 | 28 - 4 | 3 | 2 | 1 | 0
+	 *   BA     Reserved  C   D   V
+	 */
+	cprcr	r6, cpcr30
+	lsri	r6, 29
+	lsli	r6, 29
+	addi	r6, 0xe
+	cpwcr	r6, cpcr30
+
+	movi	r6, 0
+	cpwcr	r6, cpcr31
+.endm
+#endif /* __ASM_CSKY_ENTRY_H */
diff --git a/arch/csky/abiv1/inc/abi/page.h b/arch/csky/abiv1/inc/abi/page.h
new file mode 100644
index 000000000..c86451911
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/page.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <asm/shmparam.h>
+
+extern void flush_dcache_page(struct page *page);
+
+static inline unsigned long pages_do_alias(unsigned long addr1,
+					   unsigned long addr2)
+{
+	return (addr1 ^ addr2) & (SHMLBA-1);
+}
+
+static inline void clear_user_page(void *addr, unsigned long vaddr,
+				   struct page *page)
+{
+	clear_page(addr);
+	if (pages_do_alias((unsigned long) addr, vaddr & PAGE_MASK))
+		flush_dcache_page(page);
+}
+
+static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
+				  struct page *page)
+{
+	copy_page(to, from);
+	if (pages_do_alias((unsigned long) to, vaddr & PAGE_MASK))
+		flush_dcache_page(page);
+}
diff --git a/arch/csky/abiv1/inc/abi/pgtable-bits.h b/arch/csky/abiv1/inc/abi/pgtable-bits.h
new file mode 100644
index 000000000..d605445aa
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/pgtable-bits.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PGTABLE_BITS_H
+#define __ASM_CSKY_PGTABLE_BITS_H
+
+/* implemented in software */
+#define _PAGE_ACCESSED		(1<<3)
+#define PAGE_ACCESSED_BIT	(3)
+
+#define _PAGE_READ		(1<<1)
+#define _PAGE_WRITE		(1<<2)
+#define _PAGE_PRESENT		(1<<0)
+
+#define _PAGE_MODIFIED		(1<<4)
+#define PAGE_MODIFIED_BIT	(4)
+
+/* implemented in hardware */
+#define _PAGE_GLOBAL		(1<<6)
+
+#define _PAGE_VALID		(1<<7)
+#define PAGE_VALID_BIT		(7)
+
+#define _PAGE_DIRTY		(1<<8)
+#define PAGE_DIRTY_BIT		(8)
+
+#define _PAGE_CACHE		(3<<9)
+#define _PAGE_UNCACHE		(2<<9)
+#define _PAGE_SO		_PAGE_UNCACHE
+
+#define _CACHE_MASK		(7<<9)
+
+#define _CACHE_CACHED		(_PAGE_VALID | _PAGE_CACHE)
+#define _CACHE_UNCACHED		(_PAGE_VALID | _PAGE_UNCACHE)
+
+#define HAVE_ARCH_UNMAPPED_AREA
+
+#endif /* __ASM_CSKY_PGTABLE_BITS_H */
diff --git a/arch/csky/abiv1/inc/abi/reg_ops.h b/arch/csky/abiv1/inc/abi/reg_ops.h
new file mode 100644
index 000000000..a153bd391
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/reg_ops.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ABI_REG_OPS_H
+#define __ABI_REG_OPS_H
+#include <asm/reg_ops.h>
+
+#define cprcr(reg)					\
+({							\
+	unsigned int tmp;				\
+	asm volatile("cprcr %0, "reg"\n":"=b"(tmp));	\
+	tmp;						\
+})
+
+#define cpwcr(reg, val)					\
+({							\
+	asm volatile("cpwcr %0, "reg"\n"::"b"(val));	\
+})
+
+static inline unsigned int mfcr_hint(void)
+{
+	return mfcr("cr30");
+}
+
+static inline unsigned int mfcr_ccr2(void) { return 0; }
+
+#endif /* __ABI_REG_OPS_H */
diff --git a/arch/csky/abiv1/inc/abi/regdef.h b/arch/csky/abiv1/inc/abi/regdef.h
new file mode 100644
index 000000000..104707fbd
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/regdef.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_REGDEF_H
+#define __ASM_CSKY_REGDEF_H
+
+#define syscallid	r1
+#define regs_syscallid(regs) regs->regs[9]
+#define regs_fp(regs) regs->regs[2]
+
+/*
+ * PSR format:
+ * | 31 | 30-24 | 23-16 | 15 14 | 13-0 |
+ *   S     CPID     VEC     TM
+ *
+ *    S: Super Mode
+ * CPID: Coprocessor id, only 15 for MMU
+ *  VEC: Exception Number
+ *   TM: Trace Mode
+ */
+#define DEFAULT_PSR_VALUE	0x8f000000
+
+#define SYSTRACE_SAVENUM	2
+
+#define TRAP0_SIZE		2
+
+#endif /* __ASM_CSKY_REGDEF_H */
diff --git a/arch/csky/abiv1/inc/abi/string.h b/arch/csky/abiv1/inc/abi/string.h
new file mode 100644
index 000000000..0cd43384f
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/string.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ABI_CSKY_STRING_H
+#define __ABI_CSKY_STRING_H
+
+#define __HAVE_ARCH_MEMCPY
+extern void *memcpy(void *, const void *, __kernel_size_t);
+
+#endif /* __ABI_CSKY_STRING_H */
diff --git a/arch/csky/abiv1/inc/abi/switch_context.h b/arch/csky/abiv1/inc/abi/switch_context.h
new file mode 100644
index 000000000..17c826864
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/switch_context.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ABI_CSKY_PTRACE_H
+#define __ABI_CSKY_PTRACE_H
+
+struct switch_stack {
+	unsigned long r8;
+	unsigned long r9;
+	unsigned long r10;
+	unsigned long r11;
+	unsigned long r12;
+	unsigned long r13;
+	unsigned long r14;
+	unsigned long r15;
+};
+#endif /* __ABI_CSKY_PTRACE_H */
diff --git a/arch/csky/abiv1/inc/abi/vdso.h b/arch/csky/abiv1/inc/abi/vdso.h
new file mode 100644
index 000000000..14352f524
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/vdso.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/uaccess.h>
+
+static inline int setup_vdso_page(unsigned short *ptr)
+{
+	int err = 0;
+
+	/* movi r1, 127 */
+	err |= __put_user(0x67f1, ptr + 0);
+	/* addi r1, (139 - 127) */
+	err |= __put_user(0x20b1, ptr + 1);
+	/* trap 0 */
+	err |= __put_user(0x0008, ptr + 2);
+
+	return err;
+}
diff --git a/arch/csky/abiv1/memcpy.S b/arch/csky/abiv1/memcpy.S
new file mode 100644
index 000000000..5078eb516
--- /dev/null
+++ b/arch/csky/abiv1/memcpy.S
@@ -0,0 +1,347 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+
+.macro	GET_FRONT_BITS rx y
+#ifdef	__cskyLE__
+	lsri	\rx, \y
+#else
+	lsli	\rx, \y
+#endif
+.endm
+
+.macro	GET_AFTER_BITS rx y
+#ifdef	__cskyLE__
+	lsli	\rx, \y
+#else
+	lsri	\rx, \y
+#endif
+.endm
+
+/* void *memcpy(void *dest, const void *src, size_t n); */
+ENTRY(memcpy)
+	mov	r7, r2
+	cmplti	r4, 4
+	bt	.L_copy_by_byte
+	mov	r6, r2
+	andi	r6, 3
+	cmpnei	r6, 0
+	jbt	.L_dest_not_aligned
+	mov	r6, r3
+	andi	r6, 3
+	cmpnei	r6, 0
+	jbt	.L_dest_aligned_but_src_not_aligned
+.L0:
+	cmplti	r4, 16
+	jbt	.L_aligned_and_len_less_16bytes
+	subi	sp, 8
+	stw	r8, (sp, 0)
+.L_aligned_and_len_larger_16bytes:
+	ldw	r1, (r3, 0)
+	ldw	r5, (r3, 4)
+	ldw	r8, (r3, 8)
+	stw	r1, (r7, 0)
+	ldw	r1, (r3, 12)
+	stw	r5, (r7, 4)
+	stw	r8, (r7, 8)
+	stw	r1, (r7, 12)
+	subi	r4, 16
+	addi	r3, 16
+	addi	r7, 16
+	cmplti	r4, 16
+	jbf	.L_aligned_and_len_larger_16bytes
+	ldw	r8, (sp, 0)
+	addi	sp, 8
+	cmpnei	r4, 0
+	jbf	.L_return
+
+.L_aligned_and_len_less_16bytes:
+	cmplti	r4, 4
+	bt	.L_copy_by_byte
+.L1:
+	ldw	r1, (r3, 0)
+	stw	r1, (r7, 0)
+	subi	r4, 4
+	addi	r3, 4
+	addi	r7, 4
+	cmplti	r4, 4
+	jbf	.L1
+	br	.L_copy_by_byte
+
+.L_return:
+	rts
+
+.L_copy_by_byte:                      /* len less than 4 bytes */
+	cmpnei	r4, 0
+	jbf	.L_return
+.L4:
+	ldb	r1, (r3, 0)
+	stb	r1, (r7, 0)
+	addi	r3, 1
+	addi	r7, 1
+	decne	r4
+	jbt	.L4
+	rts
+
+/*
+ * If dest is not aligned, just copying some bytes makes the dest align.
+ * Afther that, we judge whether the src is aligned.
+ */
+.L_dest_not_aligned:
+	mov	r5, r3
+	rsub	r5, r5, r7
+	abs	r5, r5
+	cmplt	r5, r4
+	bt	.L_copy_by_byte
+	mov	r5, r7
+	sub	r5, r3
+	cmphs	r5, r4
+	bf	.L_copy_by_byte
+	mov	r5, r6
+.L5:
+	ldb	r1, (r3, 0)              /* makes the dest align. */
+	stb	r1, (r7, 0)
+	addi	r5, 1
+	subi	r4, 1
+	addi	r3, 1
+	addi	r7, 1
+	cmpnei	r5, 4
+	jbt	.L5
+	cmplti	r4, 4
+	jbt	.L_copy_by_byte
+	mov	r6, r3                   /* judge whether the src is aligned. */
+	andi	r6, 3
+	cmpnei	r6, 0
+	jbf	.L0
+
+/* Judge the number of misaligned, 1, 2, 3? */
+.L_dest_aligned_but_src_not_aligned:
+	mov	r5, r3
+	rsub	r5, r5, r7
+	abs	r5, r5
+	cmplt	r5, r4
+	bt	.L_copy_by_byte
+	bclri	r3, 0
+	bclri	r3, 1
+	ldw	r1, (r3, 0)
+	addi	r3, 4
+	cmpnei	r6, 2
+	bf	.L_dest_aligned_but_src_not_aligned_2bytes
+	cmpnei	r6, 3
+	bf	.L_dest_aligned_but_src_not_aligned_3bytes
+
+.L_dest_aligned_but_src_not_aligned_1byte:
+	mov	r5, r7
+	sub	r5, r3
+	cmphs	r5, r4
+	bf	.L_copy_by_byte
+	cmplti	r4, 16
+	bf	.L11
+.L10:                                     /* If the len is less than 16 bytes */
+	GET_FRONT_BITS r1 8
+	mov	r5, r1
+	ldw	r6, (r3, 0)
+	mov	r1, r6
+	GET_AFTER_BITS r6 24
+	or	r5, r6
+	stw	r5, (r7, 0)
+	subi	r4, 4
+	addi	r3, 4
+	addi	r7, 4
+	cmplti	r4, 4
+	bf	.L10
+	subi	r3, 3
+	br	.L_copy_by_byte
+.L11:
+	subi	sp, 16
+	stw	r8, (sp, 0)
+	stw	r9, (sp, 4)
+	stw	r10, (sp, 8)
+	stw	r11, (sp, 12)
+.L12:
+	ldw	r5, (r3, 0)
+	ldw	r11, (r3, 4)
+	ldw	r8, (r3, 8)
+	ldw	r9, (r3, 12)
+
+	GET_FRONT_BITS r1 8               /* little or big endian? */
+	mov	r10, r5
+	GET_AFTER_BITS r5 24
+	or	r5, r1
+
+	GET_FRONT_BITS r10 8
+	mov	r1, r11
+	GET_AFTER_BITS r11 24
+	or	r11, r10
+
+	GET_FRONT_BITS r1 8
+	mov	r10, r8
+	GET_AFTER_BITS r8 24
+	or	r8, r1
+
+	GET_FRONT_BITS r10 8
+	mov	r1, r9
+	GET_AFTER_BITS r9 24
+	or	r9, r10
+
+	stw	r5, (r7, 0)
+	stw	r11, (r7, 4)
+	stw	r8, (r7, 8)
+	stw	r9, (r7, 12)
+	subi	r4, 16
+	addi	r3, 16
+	addi	r7, 16
+	cmplti	r4, 16
+	jbf	.L12
+	ldw	r8, (sp, 0)
+	ldw	r9, (sp, 4)
+	ldw	r10, (sp, 8)
+	ldw	r11, (sp, 12)
+	addi	sp , 16
+	cmplti	r4, 4
+	bf	.L10
+	subi	r3, 3
+	br	.L_copy_by_byte
+
+.L_dest_aligned_but_src_not_aligned_2bytes:
+	cmplti	r4, 16
+	bf	.L21
+.L20:
+	GET_FRONT_BITS r1 16
+	mov	r5, r1
+	ldw	r6, (r3, 0)
+	mov	r1, r6
+	GET_AFTER_BITS r6 16
+	or	r5, r6
+	stw	r5, (r7, 0)
+	subi	r4, 4
+	addi	r3, 4
+	addi	r7, 4
+	cmplti	r4, 4
+	bf	.L20
+	subi	r3, 2
+	br	.L_copy_by_byte
+	rts
+
+.L21:	/* n > 16 */
+	subi 	sp, 16
+	stw	r8, (sp, 0)
+	stw	r9, (sp, 4)
+	stw	r10, (sp, 8)
+	stw	r11, (sp, 12)
+
+.L22:
+	ldw	r5, (r3, 0)
+	ldw	r11, (r3, 4)
+	ldw	r8, (r3, 8)
+	ldw	r9, (r3, 12)
+
+	GET_FRONT_BITS r1 16
+	mov	r10, r5
+	GET_AFTER_BITS r5 16
+	or	r5, r1
+
+	GET_FRONT_BITS r10 16
+	mov	r1, r11
+	GET_AFTER_BITS r11 16
+	or	r11, r10
+
+	GET_FRONT_BITS r1 16
+	mov	r10, r8
+	GET_AFTER_BITS r8 16
+	or	r8, r1
+
+	GET_FRONT_BITS r10 16
+	mov	r1, r9
+	GET_AFTER_BITS r9 16
+	or	r9, r10
+
+	stw	r5, (r7, 0)
+	stw	r11, (r7, 4)
+	stw	r8, (r7, 8)
+	stw	r9, (r7, 12)
+	subi	r4, 16
+	addi	r3, 16
+	addi	r7, 16
+	cmplti	r4, 16
+	jbf	.L22
+	ldw	r8, (sp, 0)
+	ldw	r9, (sp, 4)
+	ldw	r10, (sp, 8)
+	ldw	r11, (sp, 12)
+	addi	sp, 16
+	cmplti	r4, 4
+	bf	.L20
+	subi	r3, 2
+	br	.L_copy_by_byte
+
+
+.L_dest_aligned_but_src_not_aligned_3bytes:
+	cmplti	r4, 16
+	bf	.L31
+.L30:
+	GET_FRONT_BITS r1 24
+	mov	r5, r1
+	ldw	r6, (r3, 0)
+	mov	r1, r6
+	GET_AFTER_BITS r6 8
+	or	r5, r6
+	stw	r5, (r7, 0)
+	subi	r4, 4
+	addi	r3, 4
+	addi	r7, 4
+	cmplti	r4, 4
+	bf	.L30
+	subi	r3, 1
+	br	.L_copy_by_byte
+.L31:
+	subi	sp, 16
+	stw	r8, (sp, 0)
+	stw	r9, (sp, 4)
+	stw	r10, (sp, 8)
+	stw	r11, (sp, 12)
+.L32:
+	ldw	r5, (r3, 0)
+	ldw	r11, (r3, 4)
+	ldw	r8, (r3, 8)
+	ldw	r9, (r3, 12)
+
+	GET_FRONT_BITS r1 24
+	mov	r10, r5
+	GET_AFTER_BITS r5 8
+	or	r5, r1
+
+	GET_FRONT_BITS r10 24
+	mov	r1, r11
+	GET_AFTER_BITS r11 8
+	or	r11, r10
+
+	GET_FRONT_BITS r1 24
+	mov	r10, r8
+	GET_AFTER_BITS r8 8
+	or	r8, r1
+
+	GET_FRONT_BITS r10 24
+	mov	r1, r9
+	GET_AFTER_BITS r9 8
+	or	r9, r10
+
+	stw	r5, (r7, 0)
+	stw	r11, (r7, 4)
+	stw	r8, (r7, 8)
+	stw	r9, (r7, 12)
+	subi	r4, 16
+	addi	r3, 16
+	addi	r7, 16
+	cmplti	r4, 16
+	jbf	.L32
+	ldw	r8, (sp, 0)
+	ldw	r9, (sp, 4)
+	ldw	r10, (sp, 8)
+	ldw	r11, (sp, 12)
+	addi	sp, 16
+	cmplti	r4, 4
+	bf	.L30
+	subi	r3, 1
+	br	.L_copy_by_byte
diff --git a/arch/csky/abiv1/mmap.c b/arch/csky/abiv1/mmap.c
new file mode 100644
index 000000000..6792aca49
--- /dev/null
+++ b/arch/csky/abiv1/mmap.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/shm.h>
+#include <linux/sched.h>
+#include <linux/random.h>
+#include <linux/io.h>
+
+#define COLOUR_ALIGN(addr,pgoff)		\
+	((((addr)+SHMLBA-1)&~(SHMLBA-1)) +	\
+	 (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
+
+/*
+ * We need to ensure that shared mappings are correctly aligned to
+ * avoid aliasing issues with VIPT caches.  We need to ensure that
+ * a specific page of an object is always mapped at a multiple of
+ * SHMLBA bytes.
+ *
+ * We unconditionally provide this function for all cases.
+ */
+unsigned long
+arch_get_unmapped_area(struct file *filp, unsigned long addr,
+		unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+	struct mm_struct *mm = current->mm;
+	struct vm_area_struct *vma;
+	int do_align = 0;
+	struct vm_unmapped_area_info info;
+
+	/*
+	 * We only need to do colour alignment if either the I or D
+	 * caches alias.
+	 */
+	do_align = filp || (flags & MAP_SHARED);
+
+	/*
+	 * We enforce the MAP_FIXED case.
+	 */
+	if (flags & MAP_FIXED) {
+		if (flags & MAP_SHARED &&
+		    (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
+			return -EINVAL;
+		return addr;
+	}
+
+	if (len > TASK_SIZE)
+		return -ENOMEM;
+
+	if (addr) {
+		if (do_align)
+			addr = COLOUR_ALIGN(addr, pgoff);
+		else
+			addr = PAGE_ALIGN(addr);
+
+		vma = find_vma(mm, addr);
+		if (TASK_SIZE - len >= addr &&
+		    (!vma || addr + len <= vm_start_gap(vma)))
+			return addr;
+	}
+
+	info.flags = 0;
+	info.length = len;
+	info.low_limit = mm->mmap_base;
+	info.high_limit = TASK_SIZE;
+	info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
+	info.align_offset = pgoff << PAGE_SHIFT;
+	return vm_unmapped_area(&info);
+}
diff --git a/arch/csky/abiv1/strksyms.c b/arch/csky/abiv1/strksyms.c
new file mode 100644
index 000000000..c7ccbb27e
--- /dev/null
+++ b/arch/csky/abiv1/strksyms.c
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/module.h>
+
+EXPORT_SYMBOL(memcpy);
diff --git a/arch/csky/abiv2/Makefile b/arch/csky/abiv2/Makefile
new file mode 100644
index 000000000..c561efa55
--- /dev/null
+++ b/arch/csky/abiv2/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y				+= cacheflush.o
+obj-$(CONFIG_CPU_HAS_FPU)	+= fpu.o
+obj-y				+= memcmp.o
+obj-y				+= memcpy.o
+obj-y				+= memmove.o
+obj-y				+= memset.o
+obj-y				+= strcmp.o
+obj-y				+= strcpy.o
+obj-y				+= strlen.o
+obj-y				+= strksyms.o
+obj-$(CONFIG_FUNCTION_TRACER)	+= mcount.o
diff --git a/arch/csky/abiv2/cacheflush.c b/arch/csky/abiv2/cacheflush.c
new file mode 100644
index 000000000..790f1ebfb
--- /dev/null
+++ b/arch/csky/abiv2/cacheflush.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/cache.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <asm/cache.h>
+
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
+		      pte_t *pte)
+{
+	unsigned long addr;
+	struct page *page;
+
+	page = pfn_to_page(pte_pfn(*pte));
+	if (page == ZERO_PAGE(0))
+		return;
+
+	if (test_and_set_bit(PG_dcache_clean, &page->flags))
+		return;
+
+	addr = (unsigned long) kmap_atomic(page);
+
+	dcache_wb_range(addr, addr + PAGE_SIZE);
+
+	if (vma->vm_flags & VM_EXEC)
+		icache_inv_range(addr, addr + PAGE_SIZE);
+
+	kunmap_atomic((void *) addr);
+}
+
+void flush_icache_deferred(struct mm_struct *mm)
+{
+	unsigned int cpu = smp_processor_id();
+	cpumask_t *mask = &mm->context.icache_stale_mask;
+
+	if (cpumask_test_cpu(cpu, mask)) {
+		cpumask_clear_cpu(cpu, mask);
+		/*
+		 * Ensure the remote hart's writes are visible to this hart.
+		 * This pairs with a barrier in flush_icache_mm.
+		 */
+		smp_mb();
+		local_icache_inv_all(NULL);
+	}
+}
+
+void flush_icache_mm_range(struct mm_struct *mm,
+		unsigned long start, unsigned long end)
+{
+	unsigned int cpu;
+	cpumask_t others, *mask;
+
+	preempt_disable();
+
+#ifdef CONFIG_CPU_HAS_ICACHE_INS
+	if (mm == current->mm) {
+		icache_inv_range(start, end);
+		preempt_enable();
+		return;
+	}
+#endif
+
+	/* Mark every hart's icache as needing a flush for this MM. */
+	mask = &mm->context.icache_stale_mask;
+	cpumask_setall(mask);
+
+	/* Flush this hart's I$ now, and mark it as flushed. */
+	cpu = smp_processor_id();
+	cpumask_clear_cpu(cpu, mask);
+	local_icache_inv_all(NULL);
+
+	/*
+	 * Flush the I$ of other harts concurrently executing, and mark them as
+	 * flushed.
+	 */
+	cpumask_andnot(&others, mm_cpumask(mm), cpumask_of(cpu));
+
+	if (mm != current->active_mm || !cpumask_empty(&others)) {
+		on_each_cpu_mask(&others, local_icache_inv_all, NULL, 1);
+		cpumask_clear(mask);
+	}
+
+	preempt_enable();
+}
diff --git a/arch/csky/abiv2/fpu.c b/arch/csky/abiv2/fpu.c
new file mode 100644
index 000000000..5acc5c2e5
--- /dev/null
+++ b/arch/csky/abiv2/fpu.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/ptrace.h>
+#include <linux/uaccess.h>
+#include <abi/reg_ops.h>
+
+#define MTCR_MASK	0xFC00FFE0
+#define MFCR_MASK	0xFC00FFE0
+#define MTCR_DIST	0xC0006420
+#define MFCR_DIST	0xC0006020
+
+/*
+ * fpu_libc_helper() is to help libc to excute:
+ *  - mfcr %a, cr<1, 2>
+ *  - mfcr %a, cr<2, 2>
+ *  - mtcr %a, cr<1, 2>
+ *  - mtcr %a, cr<2, 2>
+ */
+int fpu_libc_helper(struct pt_regs *regs)
+{
+	int fault;
+	unsigned long instrptr, regx = 0;
+	unsigned long index = 0, tmp = 0;
+	unsigned long tinstr = 0;
+	u16 instr_hi, instr_low;
+
+	instrptr = instruction_pointer(regs);
+	if (instrptr & 1)
+		return 0;
+
+	fault = __get_user(instr_low, (u16 *)instrptr);
+	if (fault)
+		return 0;
+
+	fault = __get_user(instr_hi, (u16 *)(instrptr + 2));
+	if (fault)
+		return 0;
+
+	tinstr = instr_hi | ((unsigned long)instr_low << 16);
+
+	if (((tinstr >> 21) & 0x1F) != 2)
+		return 0;
+
+	if ((tinstr & MTCR_MASK) == MTCR_DIST) {
+		index = (tinstr >> 16) & 0x1F;
+		if (index > 13)
+			return 0;
+
+		tmp = tinstr & 0x1F;
+		if (tmp > 2)
+			return 0;
+
+		regx =  *(&regs->a0 + index);
+
+		if (tmp == 1)
+			mtcr("cr<1, 2>", regx);
+		else if (tmp == 2)
+			mtcr("cr<2, 2>", regx);
+		else
+			return 0;
+
+		regs->pc += 4;
+		return 1;
+	}
+
+	if ((tinstr & MFCR_MASK) == MFCR_DIST) {
+		index = tinstr & 0x1F;
+		if (index > 13)
+			return 0;
+
+		tmp = ((tinstr >> 16) & 0x1F);
+		if (tmp > 2)
+			return 0;
+
+		if (tmp == 1)
+			regx = mfcr("cr<1, 2>");
+		else if (tmp == 2)
+			regx = mfcr("cr<2, 2>");
+		else
+			return 0;
+
+		*(&regs->a0 + index) = regx;
+
+		regs->pc += 4;
+		return 1;
+	}
+
+	return 0;
+}
+
+void fpu_fpe(struct pt_regs *regs)
+{
+	int sig, code;
+	unsigned int fesr;
+
+	fesr = mfcr("cr<2, 2>");
+
+	sig = SIGFPE;
+	code = FPE_FLTUNK;
+
+	if (fesr & FPE_ILLE) {
+		sig = SIGILL;
+		code = ILL_ILLOPC;
+	} else if (fesr & FPE_IDC) {
+		sig = SIGILL;
+		code = ILL_ILLOPN;
+	} else if (fesr & FPE_FEC) {
+		sig = SIGFPE;
+		if (fesr & FPE_IOC)
+			code = FPE_FLTINV;
+		else if (fesr & FPE_DZC)
+			code = FPE_FLTDIV;
+		else if (fesr & FPE_UFC)
+			code = FPE_FLTUND;
+		else if (fesr & FPE_OFC)
+			code = FPE_FLTOVF;
+		else if (fesr & FPE_IXC)
+			code = FPE_FLTRES;
+	}
+
+	force_sig_fault(sig, code, (void __user *)regs->pc);
+}
+
+#define FMFVR_FPU_REGS(vrx, vry)	\
+	"fmfvrl %0, "#vrx"\n"		\
+	"fmfvrh %1, "#vrx"\n"		\
+	"fmfvrl %2, "#vry"\n"		\
+	"fmfvrh %3, "#vry"\n"
+
+#define FMTVR_FPU_REGS(vrx, vry)	\
+	"fmtvrl "#vrx", %0\n"		\
+	"fmtvrh "#vrx", %1\n"		\
+	"fmtvrl "#vry", %2\n"		\
+	"fmtvrh "#vry", %3\n"
+
+#define STW_FPU_REGS(a, b, c, d)	\
+	"stw    %0, (%4, "#a")\n"	\
+	"stw    %1, (%4, "#b")\n"	\
+	"stw    %2, (%4, "#c")\n"	\
+	"stw    %3, (%4, "#d")\n"
+
+#define LDW_FPU_REGS(a, b, c, d)	\
+	"ldw    %0, (%4, "#a")\n"	\
+	"ldw    %1, (%4, "#b")\n"	\
+	"ldw    %2, (%4, "#c")\n"	\
+	"ldw    %3, (%4, "#d")\n"
+
+void save_to_user_fp(struct user_fp *user_fp)
+{
+	unsigned long flg;
+	unsigned long tmp1, tmp2;
+	unsigned long *fpregs;
+
+	local_irq_save(flg);
+
+	tmp1 = mfcr("cr<1, 2>");
+	tmp2 = mfcr("cr<2, 2>");
+
+	user_fp->fcr = tmp1;
+	user_fp->fesr = tmp2;
+
+	fpregs = &user_fp->vr[0];
+#ifdef CONFIG_CPU_HAS_FPUV2
+#ifdef CONFIG_CPU_HAS_VDSP
+	asm volatile(
+		"vstmu.32    vr0-vr3,   (%0)\n"
+		"vstmu.32    vr4-vr7,   (%0)\n"
+		"vstmu.32    vr8-vr11,  (%0)\n"
+		"vstmu.32    vr12-vr15, (%0)\n"
+		"fstmu.64    vr16-vr31, (%0)\n"
+		: "+a"(fpregs)
+		::"memory");
+#else
+	asm volatile(
+		"fstmu.64    vr0-vr31,  (%0)\n"
+		: "+a"(fpregs)
+		::"memory");
+#endif
+#else
+	{
+	unsigned long tmp3, tmp4;
+
+	asm volatile(
+		FMFVR_FPU_REGS(vr0, vr1)
+		STW_FPU_REGS(0, 4, 16, 20)
+		FMFVR_FPU_REGS(vr2, vr3)
+		STW_FPU_REGS(32, 36, 48, 52)
+		FMFVR_FPU_REGS(vr4, vr5)
+		STW_FPU_REGS(64, 68, 80, 84)
+		FMFVR_FPU_REGS(vr6, vr7)
+		STW_FPU_REGS(96, 100, 112, 116)
+		"addi	%4, 128\n"
+		FMFVR_FPU_REGS(vr8, vr9)
+		STW_FPU_REGS(0, 4, 16, 20)
+		FMFVR_FPU_REGS(vr10, vr11)
+		STW_FPU_REGS(32, 36, 48, 52)
+		FMFVR_FPU_REGS(vr12, vr13)
+		STW_FPU_REGS(64, 68, 80, 84)
+		FMFVR_FPU_REGS(vr14, vr15)
+		STW_FPU_REGS(96, 100, 112, 116)
+		: "=a"(tmp1), "=a"(tmp2), "=a"(tmp3),
+		  "=a"(tmp4), "+a"(fpregs)
+		::"memory");
+	}
+#endif
+
+	local_irq_restore(flg);
+}
+
+void restore_from_user_fp(struct user_fp *user_fp)
+{
+	unsigned long flg;
+	unsigned long tmp1, tmp2;
+	unsigned long *fpregs;
+
+	local_irq_save(flg);
+
+	tmp1 = user_fp->fcr;
+	tmp2 = user_fp->fesr;
+
+	mtcr("cr<1, 2>", tmp1);
+	mtcr("cr<2, 2>", tmp2);
+
+	fpregs = &user_fp->vr[0];
+#ifdef CONFIG_CPU_HAS_FPUV2
+#ifdef CONFIG_CPU_HAS_VDSP
+	asm volatile(
+		"vldmu.32    vr0-vr3,   (%0)\n"
+		"vldmu.32    vr4-vr7,   (%0)\n"
+		"vldmu.32    vr8-vr11,  (%0)\n"
+		"vldmu.32    vr12-vr15, (%0)\n"
+		"fldmu.64    vr16-vr31, (%0)\n"
+		: "+a"(fpregs)
+		::"memory");
+#else
+	asm volatile(
+		"fldmu.64    vr0-vr31,  (%0)\n"
+		: "+a"(fpregs)
+		::"memory");
+#endif
+#else
+	{
+	unsigned long tmp3, tmp4;
+
+	asm volatile(
+		LDW_FPU_REGS(0, 4, 16, 20)
+		FMTVR_FPU_REGS(vr0, vr1)
+		LDW_FPU_REGS(32, 36, 48, 52)
+		FMTVR_FPU_REGS(vr2, vr3)
+		LDW_FPU_REGS(64, 68, 80, 84)
+		FMTVR_FPU_REGS(vr4, vr5)
+		LDW_FPU_REGS(96, 100, 112, 116)
+		FMTVR_FPU_REGS(vr6, vr7)
+		"addi	%4, 128\n"
+		LDW_FPU_REGS(0, 4, 16, 20)
+		FMTVR_FPU_REGS(vr8, vr9)
+		LDW_FPU_REGS(32, 36, 48, 52)
+		FMTVR_FPU_REGS(vr10, vr11)
+		LDW_FPU_REGS(64, 68, 80, 84)
+		FMTVR_FPU_REGS(vr12, vr13)
+		LDW_FPU_REGS(96, 100, 112, 116)
+		FMTVR_FPU_REGS(vr14, vr15)
+		: "=a"(tmp1), "=a"(tmp2), "=a"(tmp3),
+		  "=a"(tmp4), "+a"(fpregs)
+		::"memory");
+	}
+#endif
+	local_irq_restore(flg);
+}
diff --git a/arch/csky/abiv2/inc/abi/cacheflush.h b/arch/csky/abiv2/inc/abi/cacheflush.h
new file mode 100644
index 000000000..a565e00c3
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/cacheflush.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ABI_CSKY_CACHEFLUSH_H
+#define __ABI_CSKY_CACHEFLUSH_H
+
+/* Keep includes the same across arches.  */
+#include <linux/mm.h>
+
+/*
+ * The cache doesn't need to be flushed when TLB entries change when
+ * the cache is mapped to physical memory, not virtual memory
+ */
+#define flush_cache_all()			do { } while (0)
+#define flush_cache_mm(mm)			do { } while (0)
+#define flush_cache_dup_mm(mm)			do { } while (0)
+#define flush_cache_range(vma, start, end)	do { } while (0)
+#define flush_cache_page(vma, vmaddr, pfn)	do { } while (0)
+
+#define PG_dcache_clean		PG_arch_1
+
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
+static inline void flush_dcache_page(struct page *page)
+{
+	if (test_bit(PG_dcache_clean, &page->flags))
+		clear_bit(PG_dcache_clean, &page->flags);
+}
+
+#define flush_dcache_mmap_lock(mapping)		do { } while (0)
+#define flush_dcache_mmap_unlock(mapping)	do { } while (0)
+#define flush_icache_page(vma, page)		do { } while (0)
+
+#define flush_icache_range(start, end)		cache_wbinv_range(start, end)
+
+void flush_icache_mm_range(struct mm_struct *mm,
+			unsigned long start, unsigned long end);
+void flush_icache_deferred(struct mm_struct *mm);
+
+#define flush_cache_vmap(start, end)		do { } while (0)
+#define flush_cache_vunmap(start, end)		do { } while (0)
+
+#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
+do { \
+	memcpy(dst, src, len); \
+	if (vma->vm_flags & VM_EXEC) { \
+		dcache_wb_range((unsigned long)dst, \
+				(unsigned long)dst + len); \
+		flush_icache_mm_range(current->mm, \
+				(unsigned long)dst, \
+				(unsigned long)dst + len); \
+		} \
+} while (0)
+#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
+	memcpy(dst, src, len)
+
+#endif /* __ABI_CSKY_CACHEFLUSH_H */
diff --git a/arch/csky/abiv2/inc/abi/ckmmu.h b/arch/csky/abiv2/inc/abi/ckmmu.h
new file mode 100644
index 000000000..73ded7c72
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/ckmmu.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_CKMMUV2_H
+#define __ASM_CSKY_CKMMUV2_H
+
+#include <abi/reg_ops.h>
+#include <asm/barrier.h>
+
+static inline int read_mmu_index(void)
+{
+	return mfcr("cr<0, 15>");
+}
+
+static inline void write_mmu_index(int value)
+{
+	mtcr("cr<0, 15>", value);
+}
+
+static inline int read_mmu_entrylo0(void)
+{
+	return mfcr("cr<2, 15>");
+}
+
+static inline int read_mmu_entrylo1(void)
+{
+	return mfcr("cr<3, 15>");
+}
+
+static inline void write_mmu_pagemask(int value)
+{
+	mtcr("cr<6, 15>", value);
+}
+
+static inline int read_mmu_entryhi(void)
+{
+	return mfcr("cr<4, 15>");
+}
+
+static inline void write_mmu_entryhi(int value)
+{
+	mtcr("cr<4, 15>", value);
+}
+
+static inline unsigned long read_mmu_msa0(void)
+{
+	return mfcr("cr<30, 15>");
+}
+
+static inline void write_mmu_msa0(unsigned long value)
+{
+	mtcr("cr<30, 15>", value);
+}
+
+static inline unsigned long read_mmu_msa1(void)
+{
+	return mfcr("cr<31, 15>");
+}
+
+static inline void write_mmu_msa1(unsigned long value)
+{
+	mtcr("cr<31, 15>", value);
+}
+
+/*
+ * TLB operations.
+ */
+static inline void tlb_probe(void)
+{
+	mtcr("cr<8, 15>", 0x80000000);
+}
+
+static inline void tlb_read(void)
+{
+	mtcr("cr<8, 15>", 0x40000000);
+}
+
+static inline void tlb_invalid_all(void)
+{
+#ifdef CONFIG_CPU_HAS_TLBI
+	asm volatile("tlbi.alls\n":::"memory");
+	sync_is();
+#else
+	mtcr("cr<8, 15>", 0x04000000);
+#endif
+}
+
+static inline void local_tlb_invalid_all(void)
+{
+#ifdef CONFIG_CPU_HAS_TLBI
+	asm volatile("tlbi.all\n":::"memory");
+	sync_is();
+#else
+	tlb_invalid_all();
+#endif
+}
+
+static inline void tlb_invalid_indexed(void)
+{
+	mtcr("cr<8, 15>", 0x02000000);
+}
+
+static inline void setup_pgd(unsigned long pgd, bool kernel)
+{
+	if (kernel)
+		mtcr("cr<28, 15>", pgd | BIT(0));
+	else
+		mtcr("cr<29, 15>", pgd | BIT(0));
+}
+
+static inline unsigned long get_pgd(void)
+{
+	return mfcr("cr<29, 15>") & ~BIT(0);
+}
+#endif /* __ASM_CSKY_CKMMUV2_H */
diff --git a/arch/csky/abiv2/inc/abi/elf.h b/arch/csky/abiv2/inc/abi/elf.h
new file mode 100644
index 000000000..290f49ef4
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/elf.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ABI_CSKY_ELF_H
+#define __ABI_CSKY_ELF_H
+
+/* The member sort in array pr_reg[x] is defined by GDB. */
+#define ELF_CORE_COPY_REGS(pr_reg, regs) do {	\
+	pr_reg[0] = regs->pc;			\
+	pr_reg[1] = regs->a1;			\
+	pr_reg[2] = regs->a0;			\
+	pr_reg[3] = regs->sr;			\
+	pr_reg[4] = regs->a2;			\
+	pr_reg[5] = regs->a3;			\
+	pr_reg[6] = regs->regs[0];		\
+	pr_reg[7] = regs->regs[1];		\
+	pr_reg[8] = regs->regs[2];		\
+	pr_reg[9] = regs->regs[3];		\
+	pr_reg[10] = regs->regs[4];		\
+	pr_reg[11] = regs->regs[5];		\
+	pr_reg[12] = regs->regs[6];		\
+	pr_reg[13] = regs->regs[7];		\
+	pr_reg[14] = regs->regs[8];		\
+	pr_reg[15] = regs->regs[9];		\
+	pr_reg[16] = regs->usp;			\
+	pr_reg[17] = regs->lr;			\
+	pr_reg[18] = regs->exregs[0];		\
+	pr_reg[19] = regs->exregs[1];		\
+	pr_reg[20] = regs->exregs[2];		\
+	pr_reg[21] = regs->exregs[3];		\
+	pr_reg[22] = regs->exregs[4];		\
+	pr_reg[23] = regs->exregs[5];		\
+	pr_reg[24] = regs->exregs[6];		\
+	pr_reg[25] = regs->exregs[7];		\
+	pr_reg[26] = regs->exregs[8];		\
+	pr_reg[27] = regs->exregs[9];		\
+	pr_reg[28] = regs->exregs[10];		\
+	pr_reg[29] = regs->exregs[11];		\
+	pr_reg[30] = regs->exregs[12];		\
+	pr_reg[31] = regs->exregs[13];		\
+	pr_reg[32] = regs->exregs[14];		\
+	pr_reg[33] = regs->tls;			\
+} while (0);
+#endif /* __ABI_CSKY_ELF_H */
diff --git a/arch/csky/abiv2/inc/abi/entry.h b/arch/csky/abiv2/inc/abi/entry.h
new file mode 100644
index 000000000..bedcc6f06
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/entry.h
@@ -0,0 +1,302 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_ENTRY_H
+#define __ASM_CSKY_ENTRY_H
+
+#include <asm/setup.h>
+#include <abi/regdef.h>
+
+#define LSAVE_PC	8
+#define LSAVE_PSR	12
+#define LSAVE_A0	24
+#define LSAVE_A1	28
+#define LSAVE_A2	32
+#define LSAVE_A3	36
+#define LSAVE_A4	40
+#define LSAVE_A5	44
+
+#define KSPTOUSP
+#define USPTOKSP
+
+#define usp cr<14, 1>
+
+.macro SAVE_ALL epc_inc
+	subi    sp, 152
+	stw	tls, (sp, 0)
+	stw	lr, (sp, 4)
+
+	mfcr	lr, epc
+	movi	tls, \epc_inc
+	add	lr, tls
+	stw	lr, (sp, 8)
+
+	mfcr	lr, epsr
+	stw	lr, (sp, 12)
+	btsti   lr, 31
+	bf      1f
+	addi    lr, sp, 152
+	br	2f
+1:
+	mfcr	lr, usp
+2:
+	stw	lr, (sp, 16)
+
+	stw     a0, (sp, 20)
+	stw     a0, (sp, 24)
+	stw     a1, (sp, 28)
+	stw     a2, (sp, 32)
+	stw     a3, (sp, 36)
+
+	addi	sp, 40
+	stm	r4-r13, (sp)
+
+	addi    sp, 40
+	stm     r16-r30, (sp)
+#ifdef CONFIG_CPU_HAS_HILO
+	mfhi	lr
+	stw	lr, (sp, 60)
+	mflo	lr
+	stw	lr, (sp, 64)
+	mfcr	lr, cr14
+	stw	lr, (sp, 68)
+#endif
+	subi	sp, 80
+.endm
+
+.macro	RESTORE_ALL
+	ldw	tls, (sp, 0)
+	ldw	lr, (sp, 4)
+	ldw	a0, (sp, 8)
+	mtcr	a0, epc
+	ldw	a0, (sp, 12)
+	mtcr	a0, epsr
+	btsti   a0, 31
+	ldw	a0, (sp, 16)
+	mtcr	a0, usp
+	mtcr	a0, ss0
+
+#ifdef CONFIG_CPU_HAS_HILO
+	ldw	a0, (sp, 140)
+	mthi	a0
+	ldw	a0, (sp, 144)
+	mtlo	a0
+	ldw	a0, (sp, 148)
+	mtcr	a0, cr14
+#endif
+
+	ldw     a0, (sp, 24)
+	ldw     a1, (sp, 28)
+	ldw     a2, (sp, 32)
+	ldw     a3, (sp, 36)
+
+	addi	sp, 40
+	ldm	r4-r13, (sp)
+	addi    sp, 40
+	ldm     r16-r30, (sp)
+	addi    sp, 72
+	bf	1f
+	mfcr	sp, ss0
+1:
+	rte
+.endm
+
+.macro SAVE_REGS_FTRACE
+	subi    sp, 152
+	stw	tls, (sp, 0)
+	stw	lr, (sp, 4)
+
+	mfcr	lr, psr
+	stw	lr, (sp, 12)
+
+	addi    lr, sp, 152
+	stw	lr, (sp, 16)
+
+	stw     a0, (sp, 20)
+	stw     a0, (sp, 24)
+	stw     a1, (sp, 28)
+	stw     a2, (sp, 32)
+	stw     a3, (sp, 36)
+
+	addi	sp, 40
+	stm	r4-r13, (sp)
+
+	addi    sp, 40
+	stm     r16-r30, (sp)
+#ifdef CONFIG_CPU_HAS_HILO
+	mfhi	lr
+	stw	lr, (sp, 60)
+	mflo	lr
+	stw	lr, (sp, 64)
+	mfcr	lr, cr14
+	stw	lr, (sp, 68)
+#endif
+	subi	sp, 80
+.endm
+
+.macro	RESTORE_REGS_FTRACE
+	ldw	tls, (sp, 0)
+
+#ifdef CONFIG_CPU_HAS_HILO
+	ldw	a0, (sp, 140)
+	mthi	a0
+	ldw	a0, (sp, 144)
+	mtlo	a0
+	ldw	a0, (sp, 148)
+	mtcr	a0, cr14
+#endif
+
+	ldw     a0, (sp, 24)
+	ldw     a1, (sp, 28)
+	ldw     a2, (sp, 32)
+	ldw     a3, (sp, 36)
+
+	addi	sp, 40
+	ldm	r4-r13, (sp)
+	addi    sp, 40
+	ldm     r16-r30, (sp)
+	addi    sp, 72
+.endm
+
+.macro SAVE_SWITCH_STACK
+	subi    sp, 64
+	stm	r4-r11, (sp)
+	stw	lr,  (sp, 32)
+	stw	r16, (sp, 36)
+	stw	r17, (sp, 40)
+	stw	r26, (sp, 44)
+	stw	r27, (sp, 48)
+	stw	r28, (sp, 52)
+	stw	r29, (sp, 56)
+	stw	r30, (sp, 60)
+#ifdef CONFIG_CPU_HAS_HILO
+	subi	sp, 16
+	mfhi	lr
+	stw	lr, (sp, 0)
+	mflo	lr
+	stw	lr, (sp, 4)
+	mfcr	lr, cr14
+	stw	lr, (sp, 8)
+#endif
+.endm
+
+.macro RESTORE_SWITCH_STACK
+#ifdef CONFIG_CPU_HAS_HILO
+	ldw	lr, (sp, 0)
+	mthi	lr
+	ldw	lr, (sp, 4)
+	mtlo	lr
+	ldw	lr, (sp, 8)
+	mtcr	lr, cr14
+	addi	sp, 16
+#endif
+	ldm	r4-r11, (sp)
+	ldw	lr,  (sp, 32)
+	ldw	r16, (sp, 36)
+	ldw	r17, (sp, 40)
+	ldw	r26, (sp, 44)
+	ldw	r27, (sp, 48)
+	ldw	r28, (sp, 52)
+	ldw	r29, (sp, 56)
+	ldw	r30, (sp, 60)
+	addi	sp, 64
+.endm
+
+/* MMU registers operators. */
+.macro RD_MIR rx
+	mfcr	\rx, cr<0, 15>
+.endm
+
+.macro RD_MEH rx
+	mfcr	\rx, cr<4, 15>
+.endm
+
+.macro RD_MCIR rx
+	mfcr	\rx, cr<8, 15>
+.endm
+
+.macro RD_PGDR rx
+	mfcr	\rx, cr<29, 15>
+.endm
+
+.macro RD_PGDR_K rx
+	mfcr	\rx, cr<28, 15>
+.endm
+
+.macro WR_MEH rx
+	mtcr	\rx, cr<4, 15>
+.endm
+
+.macro WR_MCIR rx
+	mtcr	\rx, cr<8, 15>
+.endm
+
+.macro SETUP_MMU
+	/* Init psr and enable ee */
+	lrw	r6, DEFAULT_PSR_VALUE
+	mtcr    r6, psr
+	psrset  ee
+
+	/* Invalid I/Dcache BTB BHT */
+	movi	r6, 7
+	lsli	r6, 16
+	addi	r6, (1<<4) | 3
+	mtcr	r6, cr17
+
+	/* Invalid all TLB */
+	bgeni   r6, 26
+	mtcr	r6, cr<8, 15> /* Set MCIR */
+
+	/* Check MMU on/off */
+	mfcr	r6, cr18
+	btsti	r6, 0
+	bt	1f
+
+	/* MMU off: setup mapping tlb entry */
+	movi	r6, 0
+	mtcr	r6, cr<6, 15> /* Set MPR with 4K page size */
+
+	grs	r6, 1f /* Get current pa by PC */
+	bmaski  r7, (PAGE_SHIFT + 1) /* r7 = 0x1fff */
+	andn    r6, r7
+	mtcr	r6, cr<4, 15> /* Set MEH */
+
+	mov	r8, r6
+	movi    r7, 0x00000006
+	or      r8, r7
+	mtcr	r8, cr<2, 15> /* Set MEL0 */
+	movi    r7, 0x00001006
+	or      r8, r7
+	mtcr	r8, cr<3, 15> /* Set MEL1 */
+
+	bgeni   r8, 28
+	mtcr	r8, cr<8, 15> /* Set MCIR to write TLB */
+
+	br	2f
+1:
+	/*
+	 * MMU on: use origin MSA value from bootloader
+	 *
+	 * cr<30/31, 15> MSA register format:
+	 * 31 - 29 | 28 - 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
+	 *   BA     Reserved  SH  WA  B   SO SEC  C   D   V
+	 */
+	mfcr	r6, cr<30, 15> /* Get MSA0 */
+2:
+	lsri	r6, 29
+	lsli	r6, 29
+	addi	r6, 0x1ce
+	mtcr	r6, cr<30, 15> /* Set MSA0 */
+
+	movi    r6, 0
+	mtcr	r6, cr<31, 15> /* Clr MSA1 */
+
+	/* enable MMU */
+	mfcr    r6, cr18
+	bseti	r6, 0
+	mtcr    r6, cr18
+
+	jmpi	3f /* jump to va */
+3:
+.endm
+#endif /* __ASM_CSKY_ENTRY_H */
diff --git a/arch/csky/abiv2/inc/abi/fpu.h b/arch/csky/abiv2/inc/abi/fpu.h
new file mode 100644
index 000000000..09e2700a3
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/fpu.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_FPU_H
+#define __ASM_CSKY_FPU_H
+
+#include <asm/sigcontext.h>
+#include <asm/ptrace.h>
+
+int fpu_libc_helper(struct pt_regs *regs);
+void fpu_fpe(struct pt_regs *regs);
+
+static inline void init_fpu(void) { mtcr("cr<1, 2>", 0); }
+
+void save_to_user_fp(struct user_fp *user_fp);
+void restore_from_user_fp(struct user_fp *user_fp);
+
+/*
+ * Define the fesr bit for fpe handle.
+ */
+#define  FPE_ILLE  (1 << 16)    /* Illegal instruction  */
+#define  FPE_FEC   (1 << 7)     /* Input float-point arithmetic exception */
+#define  FPE_IDC   (1 << 5)     /* Input denormalized exception */
+#define  FPE_IXC   (1 << 4)     /* Inexact exception */
+#define  FPE_UFC   (1 << 3)     /* Underflow exception */
+#define  FPE_OFC   (1 << 2)     /* Overflow exception */
+#define  FPE_DZC   (1 << 1)     /* Divide by zero exception */
+#define  FPE_IOC   (1 << 0)     /* Invalid operation exception */
+#define  FPE_REGULAR_EXCEPTION (FPE_IXC | FPE_UFC | FPE_OFC | FPE_DZC | FPE_IOC)
+
+#ifdef CONFIG_OPEN_FPU_IDE
+#define IDE_STAT   (1 << 5)
+#else
+#define IDE_STAT   0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_IXE
+#define IXE_STAT   (1 << 4)
+#else
+#define IXE_STAT   0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_UFE
+#define UFE_STAT   (1 << 3)
+#else
+#define UFE_STAT   0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_OFE
+#define OFE_STAT   (1 << 2)
+#else
+#define OFE_STAT   0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_DZE
+#define DZE_STAT   (1 << 1)
+#else
+#define DZE_STAT   0
+#endif
+
+#ifdef CONFIG_OPEN_FPU_IOE
+#define IOE_STAT   (1 << 0)
+#else
+#define IOE_STAT   0
+#endif
+
+#endif /* __ASM_CSKY_FPU_H */
diff --git a/arch/csky/abiv2/inc/abi/page.h b/arch/csky/abiv2/inc/abi/page.h
new file mode 100644
index 000000000..0a70cb553
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/page.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+static inline void clear_user_page(void *addr, unsigned long vaddr,
+				   struct page *page)
+{
+	clear_page(addr);
+}
+
+static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
+				  struct page *page)
+{
+	copy_page(to, from);
+}
diff --git a/arch/csky/abiv2/inc/abi/pgtable-bits.h b/arch/csky/abiv2/inc/abi/pgtable-bits.h
new file mode 100644
index 000000000..137f7932c
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/pgtable-bits.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PGTABLE_BITS_H
+#define __ASM_CSKY_PGTABLE_BITS_H
+
+/* implemented in software */
+#define _PAGE_ACCESSED		(1<<7)
+#define PAGE_ACCESSED_BIT	(7)
+
+#define _PAGE_READ		(1<<8)
+#define _PAGE_WRITE		(1<<9)
+#define _PAGE_PRESENT		(1<<10)
+
+#define _PAGE_MODIFIED		(1<<11)
+#define PAGE_MODIFIED_BIT	(11)
+
+/* implemented in hardware */
+#define _PAGE_GLOBAL		(1<<0)
+
+#define _PAGE_VALID		(1<<1)
+#define PAGE_VALID_BIT		(1)
+
+#define _PAGE_DIRTY		(1<<2)
+#define PAGE_DIRTY_BIT		(2)
+
+#define _PAGE_SO		(1<<5)
+#define _PAGE_BUF		(1<<6)
+
+#define _PAGE_CACHE		(1<<3)
+
+#define _CACHE_MASK		_PAGE_CACHE
+
+#define _CACHE_CACHED		(_PAGE_VALID | _PAGE_CACHE | _PAGE_BUF)
+#define _CACHE_UNCACHED		(_PAGE_VALID)
+
+#endif /* __ASM_CSKY_PGTABLE_BITS_H */
diff --git a/arch/csky/abiv2/inc/abi/reg_ops.h b/arch/csky/abiv2/inc/abi/reg_ops.h
new file mode 100644
index 000000000..ae82c3f26
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/reg_ops.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ABI_REG_OPS_H
+#define __ABI_REG_OPS_H
+#include <asm/reg_ops.h>
+
+static inline unsigned int mfcr_hint(void)
+{
+	return mfcr("cr31");
+}
+
+static inline unsigned int mfcr_ccr2(void)
+{
+	return mfcr("cr23");
+}
+#endif /* __ABI_REG_OPS_H */
diff --git a/arch/csky/abiv2/inc/abi/regdef.h b/arch/csky/abiv2/inc/abi/regdef.h
new file mode 100644
index 000000000..d7328bbc1
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/regdef.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_REGDEF_H
+#define __ASM_CSKY_REGDEF_H
+
+#define syscallid	r7
+#define regs_syscallid(regs) regs->regs[3]
+#define regs_fp(regs) regs->regs[4]
+
+/*
+ * PSR format:
+ * | 31 | 30-24 | 23-16 | 15 14 | 13-10 | 9 | 8-0 |
+ *   S              VEC     TM            MM
+ *
+ *   S: Super Mode
+ * VEC: Exception Number
+ *  TM: Trace Mode
+ *  MM: Memory unaligned addr access
+ */
+#define DEFAULT_PSR_VALUE	0x80000200
+
+#define SYSTRACE_SAVENUM	5
+
+#define TRAP0_SIZE		4
+
+#endif /* __ASM_CSKY_REGDEF_H */
diff --git a/arch/csky/abiv2/inc/abi/string.h b/arch/csky/abiv2/inc/abi/string.h
new file mode 100644
index 000000000..f01bad2ac
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/string.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ABI_CSKY_STRING_H
+#define __ABI_CSKY_STRING_H
+
+#define __HAVE_ARCH_MEMCMP
+extern int memcmp(const void *, const void *, __kernel_size_t);
+
+#define __HAVE_ARCH_MEMCPY
+extern void *memcpy(void *, const void *, __kernel_size_t);
+
+#define __HAVE_ARCH_MEMMOVE
+extern void *memmove(void *, const void *, __kernel_size_t);
+
+#define __HAVE_ARCH_MEMSET
+extern void *memset(void *, int,  __kernel_size_t);
+
+#define __HAVE_ARCH_STRCMP
+extern int strcmp(const char *, const char *);
+
+#define __HAVE_ARCH_STRCPY
+extern char *strcpy(char *, const char *);
+
+#define __HAVE_ARCH_STRLEN
+extern __kernel_size_t strlen(const char *);
+
+#endif /* __ABI_CSKY_STRING_H */
diff --git a/arch/csky/abiv2/inc/abi/switch_context.h b/arch/csky/abiv2/inc/abi/switch_context.h
new file mode 100644
index 000000000..73a81245a
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/switch_context.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ABI_CSKY_PTRACE_H
+#define __ABI_CSKY_PTRACE_H
+
+struct switch_stack {
+#ifdef CONFIG_CPU_HAS_HILO
+	unsigned long rhi;
+	unsigned long rlo;
+	unsigned long cr14;
+	unsigned long pad;
+#endif
+	unsigned long r4;
+	unsigned long r5;
+	unsigned long r6;
+	unsigned long r7;
+	unsigned long r8;
+	unsigned long r9;
+	unsigned long r10;
+	unsigned long r11;
+
+	unsigned long r15;
+	unsigned long r16;
+	unsigned long r17;
+	unsigned long r26;
+	unsigned long r27;
+	unsigned long r28;
+	unsigned long r29;
+	unsigned long r30;
+};
+#endif /* __ABI_CSKY_PTRACE_H */
diff --git a/arch/csky/abiv2/inc/abi/vdso.h b/arch/csky/abiv2/inc/abi/vdso.h
new file mode 100644
index 000000000..b60d4a070
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/vdso.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ABI_CSKY_VDSO_H
+#define __ABI_CSKY_VDSO_H
+
+#include <linux/uaccess.h>
+
+static inline int setup_vdso_page(unsigned short *ptr)
+{
+	int err = 0;
+
+	/* movi r7, 173 */
+	err |= __put_user(0xea07, ptr);
+	err |= __put_user(0x008b,      ptr+1);
+
+	/* trap 0 */
+	err |= __put_user(0xc000,   ptr+2);
+	err |= __put_user(0x2020,   ptr+3);
+
+	return err;
+}
+
+#endif /* __ABI_CSKY_STRING_H */
diff --git a/arch/csky/abiv2/mcount.S b/arch/csky/abiv2/mcount.S
new file mode 100644
index 000000000..d745e10c1
--- /dev/null
+++ b/arch/csky/abiv2/mcount.S
@@ -0,0 +1,211 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include <asm/ftrace.h>
+#include <abi/entry.h>
+#include <asm/asm-offsets.h>
+
+/*
+ * csky-gcc with -pg will put the following asm after prologue:
+ *      push	r15
+ *      jsri	_mcount
+ *
+ * stack layout after mcount_enter in _mcount():
+ *
+ * current sp => 0:+-------+
+ *                 | a0-a3 | -> must save all argument regs
+ *             +16:+-------+
+ *                 | lr    | -> _mcount lr (instrumente function's pc)
+ *             +20:+-------+
+ *                 | fp=r8 | -> instrumented function fp
+ *             +24:+-------+
+ *                 | plr   | -> instrumented function lr (parent's pc)
+ *                 +-------+
+ */
+
+.macro mcount_enter
+	subi	sp, 24
+	stw	a0, (sp, 0)
+	stw	a1, (sp, 4)
+	stw	a2, (sp, 8)
+	stw	a3, (sp, 12)
+	stw	lr, (sp, 16)
+	stw	r8, (sp, 20)
+.endm
+
+.macro mcount_exit
+	ldw	a0, (sp, 0)
+	ldw	a1, (sp, 4)
+	ldw	a2, (sp, 8)
+	ldw	a3, (sp, 12)
+	ldw	t1, (sp, 16)
+	ldw	r8, (sp, 20)
+	ldw	lr, (sp, 24)
+	addi	sp, 28
+	jmp	t1
+.endm
+
+.macro mcount_enter_regs
+	subi	sp, 8
+	stw	lr, (sp, 0)
+	stw	r8, (sp, 4)
+	SAVE_REGS_FTRACE
+.endm
+
+.macro mcount_exit_regs
+	RESTORE_REGS_FTRACE
+	subi	sp, 152
+	ldw	t1, (sp, 4)
+	addi	sp, 152
+	ldw	r8, (sp, 4)
+	ldw	lr, (sp, 8)
+	addi	sp, 12
+	jmp	t1
+.endm
+
+.macro save_return_regs
+	subi	sp, 16
+	stw	a0, (sp, 0)
+	stw	a1, (sp, 4)
+	stw	a2, (sp, 8)
+	stw	a3, (sp, 12)
+.endm
+
+.macro restore_return_regs
+	mov	lr, a0
+	ldw	a0, (sp, 0)
+	ldw	a1, (sp, 4)
+	ldw	a2, (sp, 8)
+	ldw	a3, (sp, 12)
+	addi	sp, 16
+.endm
+
+.macro nop32_stub
+	nop32
+	nop32
+	nop32
+.endm
+
+ENTRY(ftrace_stub)
+	jmp	lr
+END(ftrace_stub)
+
+#ifndef CONFIG_DYNAMIC_FTRACE
+ENTRY(_mcount)
+	mcount_enter
+
+	/* r26 is link register, only used with jsri translation */
+	lrw	r26, ftrace_trace_function
+	ldw	r26, (r26, 0)
+	lrw	a1, ftrace_stub
+	cmpne	r26, a1
+	bf	skip_ftrace
+
+	mov	a0, lr
+	subi	a0, 4
+	ldw	a1, (sp, 24)
+	lrw	a2, function_trace_op
+	ldw	a2, (a2, 0)
+
+	jsr	r26
+
+#ifndef CONFIG_FUNCTION_GRAPH_TRACER
+skip_ftrace:
+	mcount_exit
+#else
+skip_ftrace:
+	lrw	a0, ftrace_graph_return
+	ldw	a0, (a0, 0)
+	lrw	a1, ftrace_stub
+	cmpne	a0, a1
+	bt	ftrace_graph_caller
+
+	lrw	a0, ftrace_graph_entry
+	ldw	a0, (a0, 0)
+	lrw	a1, ftrace_graph_entry_stub
+	cmpne	a0, a1
+	bt	ftrace_graph_caller
+
+	mcount_exit
+#endif
+END(_mcount)
+#else /* CONFIG_DYNAMIC_FTRACE */
+ENTRY(_mcount)
+	mov	t1, lr
+	ldw	lr, (sp, 0)
+	addi	sp, 4
+	jmp	t1
+ENDPROC(_mcount)
+
+ENTRY(ftrace_caller)
+	mcount_enter
+
+	ldw	a0, (sp, 16)
+	subi	a0, 4
+	ldw	a1, (sp, 24)
+	lrw	a2, function_trace_op
+	ldw	a2, (a2, 0)
+
+	nop
+GLOBAL(ftrace_call)
+	nop32_stub
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	nop
+GLOBAL(ftrace_graph_call)
+	nop32_stub
+#endif
+
+	mcount_exit
+ENDPROC(ftrace_caller)
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+	mov	a0, sp
+	addi	a0, 24
+	ldw	a1, (sp, 16)
+	subi	a1, 4
+	mov	a2, r8
+	lrw	r26, prepare_ftrace_return
+	jsr	r26
+	mcount_exit
+END(ftrace_graph_caller)
+
+ENTRY(return_to_handler)
+	save_return_regs
+	mov	a0, r8
+	jsri	ftrace_return_to_handler
+	restore_return_regs
+	jmp	lr
+END(return_to_handler)
+#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ENTRY(ftrace_regs_caller)
+	mcount_enter_regs
+
+	lrw	t1, PT_FRAME_SIZE
+	add	t1, sp
+
+	ldw	a0, (t1, 0)
+	subi	a0, 4
+	ldw	a1, (t1, 8)
+	lrw	a2, function_trace_op
+	ldw	a2, (a2, 0)
+	mov	a3, sp
+
+	nop
+GLOBAL(ftrace_regs_call)
+	nop32_stub
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	nop
+GLOBAL(ftrace_graph_regs_call)
+	nop32_stub
+#endif
+
+	mcount_exit_regs
+ENDPROC(ftrace_regs_caller)
+#endif /* CONFIG_DYNAMIC_FTRACE */
diff --git a/arch/csky/abiv2/memcmp.S b/arch/csky/abiv2/memcmp.S
new file mode 100644
index 000000000..bf0d809f0
--- /dev/null
+++ b/arch/csky/abiv2/memcmp.S
@@ -0,0 +1,152 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include "sysdep.h"
+
+ENTRY(memcmp)
+	/* Test if len less than 4 bytes.  */
+	mov	r3, r0
+	movi	r0, 0
+	mov	r12, r4
+	cmplti	r2, 4
+	bt	.L_compare_by_byte
+
+	andi	r13, r0, 3
+	movi	r19, 4
+
+	/* Test if s1 is not 4 bytes aligned.  */
+	bnez	r13, .L_s1_not_aligned
+
+	LABLE_ALIGN
+.L_s1_aligned:
+	/* If dest is aligned, then copy.  */
+	zext	r18, r2, 31, 4
+	/* Test if len less than 16 bytes.  */
+	bez	r18, .L_compare_by_word
+
+.L_compare_by_4word:
+	/* If aligned, load word each time.  */
+	ldw	r20, (r3, 0)
+	ldw	r21, (r1, 0)
+	/* If s1[i] != s2[i], goto .L_byte_check.  */
+	cmpne	r20, r21
+	bt	.L_byte_check
+
+	ldw	r20, (r3, 4)
+	ldw	r21, (r1, 4)
+	cmpne	r20, r21
+	bt	.L_byte_check
+
+	ldw	r20, (r3, 8)
+	ldw	r21, (r1, 8)
+	cmpne	r20, r21
+	bt	.L_byte_check
+
+	ldw	r20, (r3, 12)
+	ldw	r21, (r1, 12)
+	cmpne	r20, r21
+	bt	.L_byte_check
+
+	PRE_BNEZAD (r18)
+	addi	a3, 16
+	addi	a1, 16
+
+	BNEZAD (r18, .L_compare_by_4word)
+
+.L_compare_by_word:
+	zext	r18, r2, 3, 2
+	bez	r18, .L_compare_by_byte
+.L_compare_by_word_loop:
+	ldw	r20, (r3, 0)
+	ldw	r21, (r1, 0)
+	addi	r3, 4
+	PRE_BNEZAD (r18)
+	cmpne	r20, r21
+	addi    r1, 4
+	bt	.L_byte_check
+	BNEZAD (r18, .L_compare_by_word_loop)
+
+.L_compare_by_byte:
+        zext    r18, r2, 1, 0
+        bez     r18, .L_return
+.L_compare_by_byte_loop:
+        ldb     r0, (r3, 0)
+        ldb     r4, (r1, 0)
+        addi    r3, 1
+        subu    r0, r4
+        PRE_BNEZAD (r18)
+        addi    r1, 1
+        bnez    r0, .L_return
+        BNEZAD (r18, .L_compare_by_byte_loop)
+
+.L_return:
+        mov     r4, r12
+        rts
+
+# ifdef __CSKYBE__
+/* d[i] != s[i] in word, so we check byte 0.  */
+.L_byte_check:
+        xtrb0   r0, r20
+        xtrb0   r2, r21
+        subu    r0, r2
+        bnez    r0, .L_return
+
+        /* check byte 1 */
+        xtrb1   r0, r20
+        xtrb1   r2, r21
+        subu    r0, r2
+        bnez    r0, .L_return
+
+        /* check byte 2 */
+        xtrb2   r0, r20
+        xtrb2   r2, r21
+        subu    r0, r2
+        bnez    r0, .L_return
+
+        /* check byte 3 */
+        xtrb3   r0, r20
+        xtrb3   r2, r21
+        subu    r0, r2
+# else
+/* s1[i] != s2[i] in word, so we check byte 3.  */
+.L_byte_check:
+	xtrb3	r0, r20
+	xtrb3	r2, r21
+        subu    r0, r2
+        bnez    r0, .L_return
+
+	/* check byte 2 */
+	xtrb2	r0, r20
+	xtrb2	r2, r21
+        subu    r0, r2
+        bnez    r0, .L_return
+
+	/* check byte 1 */
+	xtrb1	r0, r20
+	xtrb1	r2, r21
+	subu	r0, r2
+	bnez    r0, .L_return
+
+	/* check byte 0 */
+	xtrb0	r0, r20
+	xtrb0	r2, r21
+	subu	r0, r2
+	br	.L_return
+# endif /* !__CSKYBE__ */
+
+/* Compare when s1 is not aligned.  */
+.L_s1_not_aligned:
+	sub	r13, r19, r13
+	sub	r2, r13
+.L_s1_not_aligned_loop:
+	ldb	r0, (r3, 0)
+	ldb	r4, (r1, 0)
+	addi	r3, 1
+	subu	r0, r4
+	PRE_BNEZAD (r13)
+	addi	r1, 1
+	bnez	r0, .L_return
+	BNEZAD (r13, .L_s1_not_aligned_loop)
+	br	.L_s1_aligned
+ENDPROC(memcmp)
diff --git a/arch/csky/abiv2/memcpy.S b/arch/csky/abiv2/memcpy.S
new file mode 100644
index 000000000..145bf3a93
--- /dev/null
+++ b/arch/csky/abiv2/memcpy.S
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include "sysdep.h"
+
+ENTRY(__memcpy)
+ENTRY(memcpy)
+	/* Test if len less than 4 bytes.  */
+	mov	r12, r0
+	cmplti	r2, 4
+	bt	.L_copy_by_byte
+
+	andi	r13, r0, 3
+	movi	r19, 4
+	/* Test if dest is not 4 bytes aligned.  */
+	bnez	r13, .L_dest_not_aligned
+
+/* Hardware can handle unaligned access directly.  */
+.L_dest_aligned:
+	/* If dest is aligned, then copy.  */
+	zext	r18, r2, 31, 4
+
+	/* Test if len less than 16 bytes.  */
+	bez	r18, .L_len_less_16bytes
+	movi	r19, 0
+
+	LABLE_ALIGN
+.L_len_larger_16bytes:
+#if defined(__CK860__)
+	ldw	r3, (r1, 0)
+	stw	r3, (r0, 0)
+	ldw	r3, (r1, 4)
+	stw	r3, (r0, 4)
+	ldw	r3, (r1, 8)
+	stw	r3, (r0, 8)
+	ldw	r3, (r1, 12)
+	addi	r1, 16
+	stw	r3, (r0, 12)
+	addi	r0, 16
+#else
+	ldw	r20, (r1, 0)
+	ldw	r21, (r1, 4)
+	ldw	r22, (r1, 8)
+	ldw	r23, (r1, 12)
+	stw	r20, (r0, 0)
+	stw	r21, (r0, 4)
+	stw	r22, (r0, 8)
+	stw	r23, (r0, 12)
+	PRE_BNEZAD (r18)
+	addi	r1, 16
+	addi	r0, 16
+#endif
+	BNEZAD (r18, .L_len_larger_16bytes)
+
+.L_len_less_16bytes:
+	zext	r18, r2, 3, 2
+	bez	r18, .L_copy_by_byte
+.L_len_less_16bytes_loop:
+	ldw	r3, (r1, 0)
+	PRE_BNEZAD (r18)
+	addi	r1, 4
+	stw	r3, (r0, 0)
+	addi	r0, 4
+	BNEZAD (r18, .L_len_less_16bytes_loop)
+
+/* Test if len less than 4 bytes.  */
+.L_copy_by_byte:
+	zext	r18, r2, 1, 0
+	bez	r18, .L_return
+.L_copy_by_byte_loop:
+	ldb	r3, (r1, 0)
+	PRE_BNEZAD (r18)
+	addi	r1, 1
+	stb	r3, (r0, 0)
+	addi	r0, 1
+	BNEZAD (r18, .L_copy_by_byte_loop)
+
+.L_return:
+	mov	r0, r12
+	rts
+
+/*
+ * If dest is not aligned, just copying some bytes makes the
+ * dest align.
+ */
+.L_dest_not_aligned:
+	sub	r13, r19, r13
+	sub	r2, r13
+
+/* Makes the dest align.  */
+.L_dest_not_aligned_loop:
+	ldb	r3, (r1, 0)
+	PRE_BNEZAD (r13)
+	addi	r1, 1
+	stb	r3, (r0, 0)
+	addi	r0, 1
+	BNEZAD (r13, .L_dest_not_aligned_loop)
+	cmplti	r2, 4
+	bt	.L_copy_by_byte
+
+	/* Check whether the src is aligned.  */
+	jbr	.L_dest_aligned
+ENDPROC(__memcpy)
diff --git a/arch/csky/abiv2/memmove.S b/arch/csky/abiv2/memmove.S
new file mode 100644
index 000000000..5721e73ad
--- /dev/null
+++ b/arch/csky/abiv2/memmove.S
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include "sysdep.h"
+
+	.weak memmove
+ENTRY(__memmove)
+ENTRY(memmove)
+	subu	r3, r0, r1
+	cmphs	r3, r2
+	bt	memcpy
+
+	mov	r12, r0
+	addu	r0, r0, r2
+	addu	r1, r1, r2
+
+	/* Test if len less than 4 bytes.  */
+	cmplti	r2, 4
+	bt	.L_copy_by_byte
+
+	andi	r13, r0, 3
+	/* Test if dest is not 4 bytes aligned.  */
+	bnez	r13, .L_dest_not_aligned
+	/* Hardware can handle unaligned access directly.  */
+.L_dest_aligned:
+	/* If dest is aligned, then copy.  */
+	zext	r18, r2, 31, 4
+	/* Test if len less than 16 bytes.  */
+	bez	r18, .L_len_less_16bytes
+	movi	r19, 0
+
+	/* len > 16 bytes */
+	LABLE_ALIGN
+.L_len_larger_16bytes:
+	subi	r1, 16
+	subi	r0, 16
+#if defined(__CK860__)
+	ldw	r3, (r1, 12)
+	stw	r3, (r0, 12)
+	ldw	r3, (r1, 8)
+	stw	r3, (r0, 8)
+	ldw	r3, (r1, 4)
+	stw	r3, (r0, 4)
+	ldw	r3, (r1, 0)
+	stw	r3, (r0, 0)
+#else
+	ldw	r20, (r1, 0)
+	ldw	r21, (r1, 4)
+	ldw	r22, (r1, 8)
+	ldw	r23, (r1, 12)
+	stw	r20, (r0, 0)
+	stw	r21, (r0, 4)
+	stw	r22, (r0, 8)
+	stw	r23, (r0, 12)
+	PRE_BNEZAD (r18)
+#endif
+	BNEZAD (r18, .L_len_larger_16bytes)
+
+.L_len_less_16bytes:
+	zext	r18, r2, 3, 2
+	bez	r18, .L_copy_by_byte
+.L_len_less_16bytes_loop:
+	subi	r1, 4
+	subi	r0, 4
+	ldw	r3, (r1, 0)
+	PRE_BNEZAD (r18)
+	stw	r3, (r0, 0)
+	BNEZAD (r18, .L_len_less_16bytes_loop)
+
+	/* Test if len less than 4 bytes.  */
+.L_copy_by_byte:
+	zext	r18, r2, 1, 0
+	bez	r18, .L_return
+.L_copy_by_byte_loop:
+	subi	r1, 1
+	subi	r0, 1
+	ldb	r3, (r1, 0)
+	PRE_BNEZAD (r18)
+	stb	r3, (r0, 0)
+	BNEZAD (r18, .L_copy_by_byte_loop)
+
+.L_return:
+	mov	r0, r12
+	rts
+
+	/* If dest is not aligned, just copy some bytes makes the dest
+	   align.  */
+.L_dest_not_aligned:
+	sub	r2, r13
+.L_dest_not_aligned_loop:
+	subi	r1, 1
+	subi	r0, 1
+	/* Makes the dest align.  */
+	ldb	r3, (r1, 0)
+	PRE_BNEZAD (r13)
+	stb	r3, (r0, 0)
+	BNEZAD (r13, .L_dest_not_aligned_loop)
+	cmplti	r2, 4
+	bt	.L_copy_by_byte
+	/* Check whether the src is aligned.  */
+	jbr	.L_dest_aligned
+ENDPROC(memmove)
+ENDPROC(__memmove)
diff --git a/arch/csky/abiv2/memset.S b/arch/csky/abiv2/memset.S
new file mode 100644
index 000000000..a7e7d994b
--- /dev/null
+++ b/arch/csky/abiv2/memset.S
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include "sysdep.h"
+
+	.weak memset
+ENTRY(__memset)
+ENTRY(memset)
+	/* Test if len less than 4 bytes.  */
+	mov	r12, r0
+	cmplti	r2, 8
+	bt	.L_set_by_byte
+
+	andi	r13, r0, 3
+	movi	r19, 4
+	/* Test if dest is not 4 bytes aligned.  */
+	bnez	r13, .L_dest_not_aligned
+	/* Hardware can handle unaligned access directly.  */
+.L_dest_aligned:
+        zextb   r3, r1
+        lsli    r1, 8
+        or      r1, r3
+        lsli    r3, r1, 16
+        or      r3, r1
+
+	/* If dest is aligned, then copy.  */
+	zext	r18, r2, 31, 4
+	/* Test if len less than 16 bytes.  */
+	bez	r18, .L_len_less_16bytes
+
+	LABLE_ALIGN
+.L_len_larger_16bytes:
+	stw	r3, (r0, 0)
+	stw	r3, (r0, 4)
+	stw	r3, (r0, 8)
+	stw	r3, (r0, 12)
+	PRE_BNEZAD (r18)
+	addi	r0, 16
+	BNEZAD (r18, .L_len_larger_16bytes)
+
+.L_len_less_16bytes:
+	zext	r18, r2, 3, 2
+	andi	r2, 3
+	bez	r18, .L_set_by_byte
+.L_len_less_16bytes_loop:
+	stw	r3, (r0, 0)
+	PRE_BNEZAD (r18)
+	addi	r0, 4
+	BNEZAD (r18, .L_len_less_16bytes_loop)
+
+	/* Test if len less than 4 bytes.  */
+.L_set_by_byte:
+	zext	r18, r2, 2, 0
+	bez	r18, .L_return
+.L_set_by_byte_loop:
+	stb	r1, (r0, 0)
+	PRE_BNEZAD (r18)
+	addi	r0, 1
+	BNEZAD (r18, .L_set_by_byte_loop)
+
+.L_return:
+	mov	r0, r12
+	rts
+
+	/* If dest is not aligned, just set some bytes makes the dest
+	   align.  */
+
+.L_dest_not_aligned:
+	sub	r13, r19, r13
+	sub	r2, r13
+.L_dest_not_aligned_loop:
+	/* Makes the dest align.  */
+	stb	r1, (r0, 0)
+	PRE_BNEZAD (r13)
+	addi	r0, 1
+	BNEZAD (r13, .L_dest_not_aligned_loop)
+	cmplti	r2, 8
+	bt	.L_set_by_byte
+	/* Check whether the src is aligned.  */
+	jbr	.L_dest_aligned
+ENDPROC(memset)
+ENDPROC(__memset)
diff --git a/arch/csky/abiv2/strcmp.S b/arch/csky/abiv2/strcmp.S
new file mode 100644
index 000000000..f8403f4d8
--- /dev/null
+++ b/arch/csky/abiv2/strcmp.S
@@ -0,0 +1,168 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include "sysdep.h"
+
+ENTRY(strcmp)
+	mov	a3, a0
+	/* Check if the s1 addr is aligned.  */
+	xor	a2, a3, a1
+	andi	a2, 0x3
+	bnez	a2, 7f
+	andi	t1, a0, 0x3
+	bnez	t1, 5f
+
+1:
+	/* If aligned, load word each time.  */
+	ldw	t0, (a3, 0)
+	ldw	t1, (a1, 0)
+	/* If s1[i] != s2[i], goto 2f.  */
+	cmpne   t0, t1
+	bt      2f
+	/* If s1[i] == s2[i], check if s1 or s2 is at the end.  */
+	tstnbz	t0
+	/* If at the end, goto 3f (finish comparing).  */
+	bf	3f
+
+	ldw	t0, (a3, 4)
+	ldw	t1, (a1, 4)
+	cmpne	t0, t1
+	bt	2f
+	tstnbz	t0
+	bf	3f
+
+	ldw	t0, (a3, 8)
+	ldw	t1, (a1, 8)
+	cmpne	t0, t1
+	bt	2f
+	tstnbz	t0
+	bf	3f
+
+	ldw	t0, (a3, 12)
+	ldw	t1, (a1, 12)
+	cmpne	t0, t1
+	bt	2f
+	tstnbz	t0
+	bf	3f
+
+	ldw	t0, (a3, 16)
+	ldw	t1, (a1, 16)
+	cmpne	t0, t1
+	bt	2f
+	tstnbz	t0
+	bf	3f
+
+	ldw	t0, (a3, 20)
+	ldw	t1, (a1, 20)
+	cmpne	t0, t1
+	bt	2f
+	tstnbz	t0
+	bf	3f
+
+	ldw	t0, (a3, 24)
+	ldw	t1, (a1, 24)
+	cmpne	t0, t1
+	bt	2f
+	tstnbz	t0
+	bf	3f
+
+	ldw	t0, (a3, 28)
+	ldw	t1, (a1, 28)
+	cmpne	t0, t1
+	bt	2f
+	tstnbz	t0
+	bf	3f
+
+	addi	a3, 32
+	addi	a1, 32
+
+	br	1b
+
+# ifdef __CSKYBE__
+	/* d[i] != s[i] in word, so we check byte 0.  */
+2:
+	xtrb0   a0, t0
+	xtrb0   a2, t1
+	subu    a0, a2
+	bez     a2, 4f
+	bnez    a0, 4f
+
+	/* check byte 1 */
+	xtrb1   a0, t0
+	xtrb1   a2, t1
+	subu    a0, a2
+	bez     a2, 4f
+	bnez    a0, 4f
+
+	/* check byte 2 */
+	xtrb2   a0, t0
+	xtrb2   a2, t1
+	subu    a0, a2
+	bez     a2, 4f
+	bnez    a0, 4f
+
+	/* check byte 3 */
+	xtrb3   a0, t0
+	xtrb3   a2, t1
+	subu    a0, a2
+# else
+	/* s1[i] != s2[i] in word, so we check byte 3.  */
+2:
+	xtrb3	a0, t0
+	xtrb3	a2, t1
+	subu    a0, a2
+	bez     a2, 4f
+	bnez    a0, 4f
+
+	/* check byte 2 */
+	xtrb2	a0, t0
+	xtrb2	a2, t1
+	subu    a0, a2
+	bez     a2, 4f
+	bnez    a0, 4f
+
+	/* check byte 1 */
+	xtrb1	a0, t0
+	xtrb1	a2, t1
+	subu	a0, a2
+	bez	a2, 4f
+	bnez    a0, 4f
+
+	/* check byte 0 */
+	xtrb0	a0, t0
+	xtrb0	a2, t1
+	subu	a0, a2
+
+# endif /* !__CSKYBE__ */
+	jmp     lr
+3:
+	movi	a0, 0
+4:
+	jmp     lr
+
+	/* Compare when s1 or s2 is not aligned.  */
+5:
+	subi    t1, 4
+6:
+	ldb	a0, (a3, 0)
+	ldb	a2, (a1, 0)
+	subu	a0, a2
+	bez	a2, 4b
+	bnez	a0, 4b
+	addi    t1, 1
+	addi	a1, 1
+	addi	a3, 1
+	bnez	t1, 6b
+	br	1b
+
+7:
+	ldb	a0, (a3, 0)
+	addi	a3, 1
+	ldb	a2, (a1, 0)
+	addi	a1, 1
+	subu    a0, a2
+	bnez    a0, 4b
+	bnez	a2, 7b
+	jmp	r15
+ENDPROC(strcmp)
diff --git a/arch/csky/abiv2/strcpy.S b/arch/csky/abiv2/strcpy.S
new file mode 100644
index 000000000..3c6d3f6a5
--- /dev/null
+++ b/arch/csky/abiv2/strcpy.S
@@ -0,0 +1,123 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include "sysdep.h"
+
+ENTRY(strcpy)
+	mov	a3, a0
+	/* Check if the src addr is aligned.  */
+        andi    t0, a1, 3
+        bnez	t0, 11f
+1:
+	/* Check if all the bytes in the word are not zero.  */
+	ldw	a2, (a1)
+	tstnbz	a2
+	bf	9f
+	stw	a2, (a3)
+
+	ldw	a2, (a1, 4)
+	tstnbz	a2
+	bf	2f
+	stw	a2, (a3, 4)
+
+	ldw	a2, (a1, 8)
+	tstnbz	a2
+	bf	3f
+	stw	a2, (a3, 8)
+
+	ldw	a2, (a1, 12)
+	tstnbz	a2
+	bf	4f
+	stw	a2, (a3, 12)
+
+	ldw	a2, (a1, 16)
+	tstnbz	a2
+	bf	5f
+	stw	a2, (a3, 16)
+
+	ldw	a2, (a1, 20)
+	tstnbz	a2
+	bf	6f
+	stw	a2, (a3, 20)
+
+	ldw	a2, (a1, 24)
+	tstnbz	a2
+	bf	7f
+	stw	a2, (a3, 24)
+
+	ldw	a2, (a1, 28)
+	tstnbz	a2
+	bf	8f
+	stw	a2, (a3, 28)
+
+	addi	a3, 32
+	addi	a1, 32
+	br	1b
+
+
+2:
+	addi	a3, 4
+	br	9f
+
+3:
+	addi	a3, 8
+	br	9f
+
+4:
+	addi	a3, 12
+	br	9f
+
+5:
+	addi	a3, 16
+	br	9f
+
+6:
+	addi	a3, 20
+	br	9f
+
+7:
+	addi	a3, 24
+	br	9f
+
+8:
+	addi	a3, 28
+9:
+# ifdef __CSKYBE__
+	xtrb0	t0, a2
+	st.b	t0, (a3)
+	bez	t0, 10f
+	xtrb1	t0, a2
+	st.b	t0, (a3, 1)
+	bez	t0, 10f
+	xtrb2	t0, a2
+	st.b	t0, (a3, 2)
+	bez	t0, 10f
+	stw	a2, (a3)
+# else
+	xtrb3	t0, a2
+	st.b	t0, (a3)
+	bez	t0, 10f
+	xtrb2	t0, a2
+	st.b	t0, (a3, 1)
+	bez	t0, 10f
+	xtrb1	t0, a2
+	st.b	t0, (a3, 2)
+	bez	t0, 10f
+	stw	a2, (a3)
+# endif	/* !__CSKYBE__ */
+10:
+	jmp	lr
+
+11:
+	subi    t0, 4
+12:
+        ld.b    a2, (a1)
+        st.b	a2, (a3)
+        bez	a2, 10b
+	addi    t0, 1
+        addi    a1, a1, 1
+        addi    a3, a3, 1
+	bnez	t0, 12b
+	jbr	1b
+ENDPROC(strcpy)
diff --git a/arch/csky/abiv2/strksyms.c b/arch/csky/abiv2/strksyms.c
new file mode 100644
index 000000000..06da723d8
--- /dev/null
+++ b/arch/csky/abiv2/strksyms.c
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/module.h>
+
+EXPORT_SYMBOL(memcpy);
+EXPORT_SYMBOL(memset);
+EXPORT_SYMBOL(memcmp);
+EXPORT_SYMBOL(memmove);
+EXPORT_SYMBOL(strcmp);
+EXPORT_SYMBOL(strcpy);
+EXPORT_SYMBOL(strlen);
diff --git a/arch/csky/abiv2/strlen.S b/arch/csky/abiv2/strlen.S
new file mode 100644
index 000000000..bcdd70764
--- /dev/null
+++ b/arch/csky/abiv2/strlen.S
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include "sysdep.h"
+
+ENTRY(strlen)
+	/* Check if the start addr is aligned.  */
+	mov	r3, r0
+	andi	r1, r0, 3
+	movi	r2, 4
+	movi	r0, 0
+	bnez	r1, .L_start_not_aligned
+
+	LABLE_ALIGN
+.L_start_addr_aligned:
+	/* Check if all the bytes in the word are not zero.  */
+	ldw	r1, (r3)
+	tstnbz	r1
+	bf	.L_string_tail
+
+	ldw	r1, (r3, 4)
+	addi	r0, 4
+	tstnbz	r1
+	bf	.L_string_tail
+
+	ldw	r1, (r3, 8)
+	addi	r0, 4
+	tstnbz	r1
+	bf	.L_string_tail
+
+	ldw	r1, (r3, 12)
+	addi	r0, 4
+	tstnbz	r1
+	bf	.L_string_tail
+
+	ldw	r1, (r3, 16)
+	addi	r0, 4
+	tstnbz	r1
+	bf	.L_string_tail
+
+	ldw	r1, (r3, 20)
+	addi	r0, 4
+	tstnbz	r1
+	bf	.L_string_tail
+
+	ldw	r1, (r3, 24)
+	addi	r0, 4
+	tstnbz	r1
+	bf	.L_string_tail
+
+	ldw	r1, (r3, 28)
+	addi	r0, 4
+	tstnbz	r1
+	bf	.L_string_tail
+
+	addi	r0, 4
+	addi	r3, 32
+	br	.L_start_addr_aligned
+
+.L_string_tail:
+# ifdef __CSKYBE__
+	xtrb0	r3, r1
+	bez	r3, .L_return
+	addi	r0, 1
+	xtrb1	r3, r1
+	bez	r3, .L_return
+	addi	r0, 1
+	xtrb2	r3, r1
+	bez	r3, .L_return
+	addi	r0, 1
+# else
+	xtrb3	r3, r1
+	bez	r3, .L_return
+	addi	r0, 1
+	xtrb2	r3, r1
+	bez	r3, .L_return
+	addi	r0, 1
+	xtrb1	r3, r1
+	bez	r3, .L_return
+	addi	r0, 1
+# endif	/* !__CSKYBE__ */
+
+.L_return:
+	rts
+
+.L_start_not_aligned:
+	sub	r2, r2, r1
+.L_start_not_aligned_loop:
+	ldb	r1, (r3)
+	PRE_BNEZAD (r2)
+	addi	r3, 1
+	bez	r1, .L_return
+	addi	r0, 1
+	BNEZAD (r2, .L_start_not_aligned_loop)
+	br	.L_start_addr_aligned
+ENDPROC(strlen)
diff --git a/arch/csky/abiv2/sysdep.h b/arch/csky/abiv2/sysdep.h
new file mode 100644
index 000000000..bbbedfd34
--- /dev/null
+++ b/arch/csky/abiv2/sysdep.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __SYSDEP_H
+#define __SYSDEP_H
+
+#ifdef __ASSEMBLER__
+
+#if defined(__CK860__)
+#define LABLE_ALIGN	\
+	.balignw 16, 0x6c03
+
+#define PRE_BNEZAD(R)
+
+#define BNEZAD(R, L)	\
+	bnezad	R, L
+#else
+#define LABLE_ALIGN	\
+	.balignw 8, 0x6c03
+
+#define PRE_BNEZAD(R)	\
+	subi	R, 1
+
+#define BNEZAD(R, L)	\
+	bnez	R, L
+#endif
+
+#endif
+
+#endif
diff --git a/arch/csky/boot/Makefile b/arch/csky/boot/Makefile
new file mode 100644
index 000000000..dbc9b1bd7
--- /dev/null
+++ b/arch/csky/boot/Makefile
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0-only
+targets := Image zImage uImage
+targets += $(dtb-y)
+
+$(obj)/Image: vmlinux FORCE
+	$(call if_changed,objcopy)
+	@echo '  Kernel: $@ is ready'
+
+compress-$(CONFIG_KERNEL_GZIP) = gzip
+compress-$(CONFIG_KERNEL_LZO)  = lzo
+compress-$(CONFIG_KERNEL_LZMA) = lzma
+compress-$(CONFIG_KERNEL_XZ)   = xzkern
+compress-$(CONFIG_KERNEL_LZ4)  = lz4
+
+$(obj)/zImage:  $(obj)/Image FORCE
+	$(call if_changed,$(compress-y))
+	@echo '  Kernel: $@ is ready'
+
+UIMAGE_ARCH		= sandbox
+UIMAGE_COMPRESSION	= $(compress-y)
+UIMAGE_LOADADDR		= $(shell $(NM) vmlinux | awk '$$NF == "_start" {print $$1}')
+
+$(obj)/uImage: $(obj)/zImage
+	$(call if_changed,uimage)
+	@echo 'Image: $@ is ready'
diff --git a/arch/csky/boot/dts/Makefile b/arch/csky/boot/dts/Makefile
new file mode 100644
index 000000000..5f1f55e91
--- /dev/null
+++ b/arch/csky/boot/dts/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+dtstree	:= $(srctree)/$(src)
+
+dtb-y := $(patsubst $(dtstree)/%.dts,%.dtb, $(wildcard $(dtstree)/*.dts))
diff --git a/arch/csky/configs/defconfig b/arch/csky/configs/defconfig
new file mode 100644
index 000000000..af722e4df
--- /dev/null
+++ b/arch/csky/configs/defconfig
@@ -0,0 +1,53 @@
+# CONFIG_LOCALVERSION_AUTO is not set
+CONFIG_DEFAULT_HOSTNAME="csky"
+# CONFIG_SWAP is not set
+CONFIG_SYSVIPC=y
+CONFIG_POSIX_MQUEUE=y
+CONFIG_AUDIT=y
+CONFIG_NO_HZ_IDLE=y
+CONFIG_HIGH_RES_TIMERS=y
+CONFIG_BSD_PROCESS_ACCT=y
+CONFIG_BSD_PROCESS_ACCT_V3=y
+CONFIG_MODULES=y
+CONFIG_MODULE_UNLOAD=y
+CONFIG_NET=y
+CONFIG_PACKET=y
+CONFIG_UNIX=y
+CONFIG_INET=y
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+CONFIG_BLK_DEV_LOOP=y
+CONFIG_BLK_DEV_RAM=y
+CONFIG_BLK_DEV_RAM_SIZE=65536
+CONFIG_VT_HW_CONSOLE_BINDING=y
+CONFIG_SERIAL_NONSTANDARD=y
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_OF_PLATFORM=y
+# CONFIG_VGA_CONSOLE is not set
+CONFIG_PM_DEVFREQ=y
+CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND=y
+CONFIG_DEVFREQ_GOV_PERFORMANCE=y
+CONFIG_DEVFREQ_GOV_POWERSAVE=y
+CONFIG_DEVFREQ_GOV_USERSPACE=y
+CONFIG_GENERIC_PHY=y
+CONFIG_EXT4_FS=y
+CONFIG_FANOTIFY=y
+CONFIG_QUOTA=y
+CONFIG_FSCACHE=m
+CONFIG_FSCACHE_STATS=y
+CONFIG_CACHEFILES=m
+CONFIG_MSDOS_FS=y
+CONFIG_VFAT_FS=y
+CONFIG_FAT_DEFAULT_UTF8=y
+CONFIG_NTFS_FS=y
+CONFIG_PROC_KCORE=y
+CONFIG_PROC_CHILDREN=y
+CONFIG_TMPFS=y
+CONFIG_TMPFS_POSIX_ACL=y
+CONFIG_CONFIGFS_FS=y
+CONFIG_CRAMFS=y
+CONFIG_ROMFS_FS=y
+CONFIG_NFS_FS=y
+CONFIG_PRINTK_TIME=y
+CONFIG_MAGIC_SYSRQ=y
diff --git a/arch/csky/include/asm/Kbuild b/arch/csky/include/asm/Kbuild
new file mode 100644
index 000000000..2a5a4d94f
--- /dev/null
+++ b/arch/csky/include/asm/Kbuild
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+generic-y += asm-offsets.h
+generic-y += gpio.h
+generic-y += kvm_para.h
+generic-y += qrwlock.h
+generic-y += seccomp.h
+generic-y += user.h
+generic-y += vmlinux.lds.h
diff --git a/arch/csky/include/asm/addrspace.h b/arch/csky/include/asm/addrspace.h
new file mode 100644
index 000000000..d1c2ede69
--- /dev/null
+++ b/arch/csky/include/asm/addrspace.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_ADDRSPACE_H
+#define __ASM_CSKY_ADDRSPACE_H
+
+#define KSEG0		0x80000000ul
+#define KSEG0ADDR(a)	(((unsigned long)a & 0x1fffffff) | KSEG0)
+
+#endif /* __ASM_CSKY_ADDRSPACE_H */
diff --git a/arch/csky/include/asm/asid.h b/arch/csky/include/asm/asid.h
new file mode 100644
index 000000000..ac08b0ffb
--- /dev/null
+++ b/arch/csky/include/asm/asid.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_ASM_ASID_H
+#define __ASM_ASM_ASID_H
+
+#include <linux/atomic.h>
+#include <linux/compiler.h>
+#include <linux/cpumask.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+struct asid_info
+{
+	atomic64_t	generation;
+	unsigned long	*map;
+	atomic64_t __percpu	*active;
+	u64 __percpu		*reserved;
+	u32			bits;
+	/* Lock protecting the structure */
+	raw_spinlock_t		lock;
+	/* Which CPU requires context flush on next call */
+	cpumask_t		flush_pending;
+	/* Number of ASID allocated by context (shift value) */
+	unsigned int		ctxt_shift;
+	/* Callback to locally flush the context. */
+	void			(*flush_cpu_ctxt_cb)(void);
+};
+
+#define NUM_ASIDS(info)			(1UL << ((info)->bits))
+#define NUM_CTXT_ASIDS(info)		(NUM_ASIDS(info) >> (info)->ctxt_shift)
+
+#define active_asid(info, cpu)	*per_cpu_ptr((info)->active, cpu)
+
+void asid_new_context(struct asid_info *info, atomic64_t *pasid,
+		      unsigned int cpu, struct mm_struct *mm);
+
+/*
+ * Check the ASID is still valid for the context. If not generate a new ASID.
+ *
+ * @pasid: Pointer to the current ASID batch
+ * @cpu: current CPU ID. Must have been acquired throught get_cpu()
+ */
+static inline void asid_check_context(struct asid_info *info,
+				      atomic64_t *pasid, unsigned int cpu,
+				      struct mm_struct *mm)
+{
+	u64 asid, old_active_asid;
+
+	asid = atomic64_read(pasid);
+
+	/*
+	 * The memory ordering here is subtle.
+	 * If our active_asid is non-zero and the ASID matches the current
+	 * generation, then we update the active_asid entry with a relaxed
+	 * cmpxchg. Racing with a concurrent rollover means that either:
+	 *
+	 * - We get a zero back from the cmpxchg and end up waiting on the
+	 *   lock. Taking the lock synchronises with the rollover and so
+	 *   we are forced to see the updated generation.
+	 *
+	 * - We get a valid ASID back from the cmpxchg, which means the
+	 *   relaxed xchg in flush_context will treat us as reserved
+	 *   because atomic RmWs are totally ordered for a given location.
+	 */
+	old_active_asid = atomic64_read(&active_asid(info, cpu));
+	if (old_active_asid &&
+	    !((asid ^ atomic64_read(&info->generation)) >> info->bits) &&
+	    atomic64_cmpxchg_relaxed(&active_asid(info, cpu),
+				     old_active_asid, asid))
+		return;
+
+	asid_new_context(info, pasid, cpu, mm);
+}
+
+int asid_allocator_init(struct asid_info *info,
+			u32 bits, unsigned int asid_per_ctxt,
+			void (*flush_cpu_ctxt_cb)(void));
+
+#endif
diff --git a/arch/csky/include/asm/atomic.h b/arch/csky/include/asm/atomic.h
new file mode 100644
index 000000000..e369d73b1
--- /dev/null
+++ b/arch/csky/include/asm/atomic.h
@@ -0,0 +1,212 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_ATOMIC_H
+#define __ASM_CSKY_ATOMIC_H
+
+#include <linux/version.h>
+#include <asm/cmpxchg.h>
+#include <asm/barrier.h>
+
+#ifdef CONFIG_CPU_HAS_LDSTEX
+
+#define __atomic_add_unless __atomic_add_unless
+static inline int __atomic_add_unless(atomic_t *v, int a, int u)
+{
+	unsigned long tmp, ret;
+
+	smp_mb();
+
+	asm volatile (
+	"1:	ldex.w		%0, (%3) \n"
+	"	mov		%1, %0   \n"
+	"	cmpne		%0, %4   \n"
+	"	bf		2f	 \n"
+	"	add		%0, %2   \n"
+	"	stex.w		%0, (%3) \n"
+	"	bez		%0, 1b   \n"
+	"2:				 \n"
+		: "=&r" (tmp), "=&r" (ret)
+		: "r" (a), "r"(&v->counter), "r"(u)
+		: "memory");
+
+	if (ret != u)
+		smp_mb();
+
+	return ret;
+}
+
+#define ATOMIC_OP(op, c_op)						\
+static inline void atomic_##op(int i, atomic_t *v)			\
+{									\
+	unsigned long tmp;						\
+									\
+	asm volatile (							\
+	"1:	ldex.w		%0, (%2) \n"				\
+	"	" #op "		%0, %1   \n"				\
+	"	stex.w		%0, (%2) \n"				\
+	"	bez		%0, 1b   \n"				\
+		: "=&r" (tmp)						\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+}
+
+#define ATOMIC_OP_RETURN(op, c_op)					\
+static inline int atomic_##op##_return(int i, atomic_t *v)		\
+{									\
+	unsigned long tmp, ret;						\
+									\
+	smp_mb();							\
+	asm volatile (							\
+	"1:	ldex.w		%0, (%3) \n"				\
+	"	" #op "		%0, %2   \n"				\
+	"	mov		%1, %0   \n"				\
+	"	stex.w		%0, (%3) \n"				\
+	"	bez		%0, 1b   \n"				\
+		: "=&r" (tmp), "=&r" (ret)				\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+	smp_mb();							\
+									\
+	return ret;							\
+}
+
+#define ATOMIC_FETCH_OP(op, c_op)					\
+static inline int atomic_fetch_##op(int i, atomic_t *v)			\
+{									\
+	unsigned long tmp, ret;						\
+									\
+	smp_mb();							\
+	asm volatile (							\
+	"1:	ldex.w		%0, (%3) \n"				\
+	"	mov		%1, %0   \n"				\
+	"	" #op "		%0, %2   \n"				\
+	"	stex.w		%0, (%3) \n"				\
+	"	bez		%0, 1b   \n"				\
+		: "=&r" (tmp), "=&r" (ret)				\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+	smp_mb();							\
+									\
+	return ret;							\
+}
+
+#else /* CONFIG_CPU_HAS_LDSTEX */
+
+#include <linux/irqflags.h>
+
+#define __atomic_add_unless __atomic_add_unless
+static inline int __atomic_add_unless(atomic_t *v, int a, int u)
+{
+	unsigned long tmp, ret, flags;
+
+	raw_local_irq_save(flags);
+
+	asm volatile (
+	"	ldw		%0, (%3) \n"
+	"	mov		%1, %0   \n"
+	"	cmpne		%0, %4   \n"
+	"	bf		2f	 \n"
+	"	add		%0, %2   \n"
+	"	stw		%0, (%3) \n"
+	"2:				 \n"
+		: "=&r" (tmp), "=&r" (ret)
+		: "r" (a), "r"(&v->counter), "r"(u)
+		: "memory");
+
+	raw_local_irq_restore(flags);
+
+	return ret;
+}
+
+#define ATOMIC_OP(op, c_op)						\
+static inline void atomic_##op(int i, atomic_t *v)			\
+{									\
+	unsigned long tmp, flags;					\
+									\
+	raw_local_irq_save(flags);					\
+									\
+	asm volatile (							\
+	"	ldw		%0, (%2) \n"				\
+	"	" #op "		%0, %1   \n"				\
+	"	stw		%0, (%2) \n"				\
+		: "=&r" (tmp)						\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+									\
+	raw_local_irq_restore(flags);					\
+}
+
+#define ATOMIC_OP_RETURN(op, c_op)					\
+static inline int atomic_##op##_return(int i, atomic_t *v)		\
+{									\
+	unsigned long tmp, ret, flags;					\
+									\
+	raw_local_irq_save(flags);					\
+									\
+	asm volatile (							\
+	"	ldw		%0, (%3) \n"				\
+	"	" #op "		%0, %2   \n"				\
+	"	stw		%0, (%3) \n"				\
+	"	mov		%1, %0   \n"				\
+		: "=&r" (tmp), "=&r" (ret)				\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+									\
+	raw_local_irq_restore(flags);					\
+									\
+	return ret;							\
+}
+
+#define ATOMIC_FETCH_OP(op, c_op)					\
+static inline int atomic_fetch_##op(int i, atomic_t *v)			\
+{									\
+	unsigned long tmp, ret, flags;					\
+									\
+	raw_local_irq_save(flags);					\
+									\
+	asm volatile (							\
+	"	ldw		%0, (%3) \n"				\
+	"	mov		%1, %0   \n"				\
+	"	" #op "		%0, %2   \n"				\
+	"	stw		%0, (%3) \n"				\
+		: "=&r" (tmp), "=&r" (ret)				\
+		: "r" (i), "r"(&v->counter)				\
+		: "memory");						\
+									\
+	raw_local_irq_restore(flags);					\
+									\
+	return ret;							\
+}
+
+#endif /* CONFIG_CPU_HAS_LDSTEX */
+
+#define atomic_add_return atomic_add_return
+ATOMIC_OP_RETURN(add, +)
+#define atomic_sub_return atomic_sub_return
+ATOMIC_OP_RETURN(sub, -)
+
+#define atomic_fetch_add atomic_fetch_add
+ATOMIC_FETCH_OP(add, +)
+#define atomic_fetch_sub atomic_fetch_sub
+ATOMIC_FETCH_OP(sub, -)
+#define atomic_fetch_and atomic_fetch_and
+ATOMIC_FETCH_OP(and, &)
+#define atomic_fetch_or atomic_fetch_or
+ATOMIC_FETCH_OP(or, |)
+#define atomic_fetch_xor atomic_fetch_xor
+ATOMIC_FETCH_OP(xor, ^)
+
+#define atomic_and atomic_and
+ATOMIC_OP(and, &)
+#define atomic_or atomic_or
+ATOMIC_OP(or, |)
+#define atomic_xor atomic_xor
+ATOMIC_OP(xor, ^)
+
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#include <asm-generic/atomic.h>
+
+#endif /* __ASM_CSKY_ATOMIC_H */
diff --git a/arch/csky/include/asm/barrier.h b/arch/csky/include/asm/barrier.h
new file mode 100644
index 000000000..a430e7fdd
--- /dev/null
+++ b/arch/csky/include/asm/barrier.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_BARRIER_H
+#define __ASM_CSKY_BARRIER_H
+
+#ifndef __ASSEMBLY__
+
+#define nop()	asm volatile ("nop\n":::"memory")
+
+/*
+ * sync:        completion barrier, all sync.xx instructions
+ *              guarantee the last response recieved by bus transaction
+ *              made by ld/st instructions before sync.s
+ * sync.s:      inherit from sync, but also shareable to other cores
+ * sync.i:      inherit from sync, but also flush cpu pipeline
+ * sync.is:     the same with sync.i + sync.s
+ *
+ * bar.brwarw:  ordering barrier for all load/store instructions before it
+ * bar.brwarws: ordering barrier for all load/store instructions before it
+ *						and shareable to other cores
+ * bar.brar:    ordering barrier for all load       instructions before it
+ * bar.brars:   ordering barrier for all load       instructions before it
+ *						and shareable to other cores
+ * bar.bwaw:    ordering barrier for all store      instructions before it
+ * bar.bwaws:   ordering barrier for all store      instructions before it
+ *						and shareable to other cores
+ */
+
+#ifdef CONFIG_CPU_HAS_CACHEV2
+#define mb()		asm volatile ("sync.s\n":::"memory")
+
+#ifdef CONFIG_SMP
+#define __smp_mb()	asm volatile ("bar.brwarws\n":::"memory")
+#define __smp_rmb()	asm volatile ("bar.brars\n":::"memory")
+#define __smp_wmb()	asm volatile ("bar.bwaws\n":::"memory")
+#endif /* CONFIG_SMP */
+
+#define sync_is()	asm volatile ("sync.is\n":::"memory")
+
+#else /* !CONFIG_CPU_HAS_CACHEV2 */
+#define mb()		asm volatile ("sync\n":::"memory")
+#endif
+
+#include <asm-generic/barrier.h>
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_CSKY_BARRIER_H */
diff --git a/arch/csky/include/asm/bitops.h b/arch/csky/include/asm/bitops.h
new file mode 100644
index 000000000..43b9838bf
--- /dev/null
+++ b/arch/csky/include/asm/bitops.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_BITOPS_H
+#define __ASM_CSKY_BITOPS_H
+
+#include <linux/compiler.h>
+#include <asm/barrier.h>
+
+/*
+ * asm-generic/bitops/ffs.h
+ */
+static inline int ffs(int x)
+{
+	if (!x)
+		return 0;
+
+	asm volatile (
+		"brev %0\n"
+		"ff1  %0\n"
+		"addi %0, 1\n"
+		: "=&r"(x)
+		: "0"(x));
+	return x;
+}
+
+/*
+ * asm-generic/bitops/__ffs.h
+ */
+static __always_inline unsigned long __ffs(unsigned long x)
+{
+	asm volatile (
+		"brev %0\n"
+		"ff1  %0\n"
+		: "=&r"(x)
+		: "0"(x));
+	return x;
+}
+
+/*
+ * asm-generic/bitops/fls.h
+ */
+static __always_inline int fls(unsigned int x)
+{
+	asm volatile(
+		"ff1 %0\n"
+		: "=&r"(x)
+		: "0"(x));
+
+	return (32 - x);
+}
+
+/*
+ * asm-generic/bitops/__fls.h
+ */
+static __always_inline unsigned long __fls(unsigned long x)
+{
+	return fls(x) - 1;
+}
+
+#include <asm-generic/bitops/ffz.h>
+#include <asm-generic/bitops/fls64.h>
+#include <asm-generic/bitops/find.h>
+
+#ifndef _LINUX_BITOPS_H
+#error only <linux/bitops.h> can be included directly
+#endif
+
+#include <asm-generic/bitops/sched.h>
+#include <asm-generic/bitops/hweight.h>
+#include <asm-generic/bitops/lock.h>
+#include <asm-generic/bitops/atomic.h>
+
+/*
+ * bug fix, why only could use atomic!!!!
+ */
+#include <asm-generic/bitops/non-atomic.h>
+#define __clear_bit(nr, vaddr) clear_bit(nr, vaddr)
+
+#include <asm-generic/bitops/le.h>
+#include <asm-generic/bitops/ext2-atomic.h>
+#endif /* __ASM_CSKY_BITOPS_H */
diff --git a/arch/csky/include/asm/bug.h b/arch/csky/include/asm/bug.h
new file mode 100644
index 000000000..33ebd16b9
--- /dev/null
+++ b/arch/csky/include/asm/bug.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_BUG_H
+#define __ASM_CSKY_BUG_H
+
+#include <linux/compiler.h>
+#include <linux/const.h>
+#include <linux/types.h>
+
+#define BUG()				\
+do {					\
+	asm volatile ("bkpt\n");	\
+	unreachable();			\
+} while (0)
+
+#define HAVE_ARCH_BUG
+
+#include <asm-generic/bug.h>
+
+struct pt_regs;
+
+void die(struct pt_regs *regs, const char *str);
+void show_regs(struct pt_regs *regs);
+void show_code(struct pt_regs *regs);
+
+#endif /* __ASM_CSKY_BUG_H */
diff --git a/arch/csky/include/asm/cache.h b/arch/csky/include/asm/cache.h
new file mode 100644
index 000000000..4b5c09bf1
--- /dev/null
+++ b/arch/csky/include/asm/cache.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_CACHE_H
+#define __ASM_CSKY_CACHE_H
+
+/* bytes per L1 cache line */
+#define L1_CACHE_SHIFT	CONFIG_L1_CACHE_SHIFT
+
+#define L1_CACHE_BYTES	(1 << L1_CACHE_SHIFT)
+
+#define ARCH_DMA_MINALIGN	L1_CACHE_BYTES
+
+#ifndef __ASSEMBLY__
+
+void dcache_wb_line(unsigned long start);
+
+void icache_inv_range(unsigned long start, unsigned long end);
+void icache_inv_all(void);
+void local_icache_inv_all(void *priv);
+
+void dcache_wb_range(unsigned long start, unsigned long end);
+void dcache_wbinv_all(void);
+
+void cache_wbinv_range(unsigned long start, unsigned long end);
+void cache_wbinv_all(void);
+
+void dma_wbinv_range(unsigned long start, unsigned long end);
+void dma_inv_range(unsigned long start, unsigned long end);
+void dma_wb_range(unsigned long start, unsigned long end);
+
+#endif
+#endif  /* __ASM_CSKY_CACHE_H */
diff --git a/arch/csky/include/asm/cacheflush.h b/arch/csky/include/asm/cacheflush.h
new file mode 100644
index 000000000..f0b8f2542
--- /dev/null
+++ b/arch/csky/include/asm/cacheflush.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_CACHEFLUSH_H
+#define __ASM_CSKY_CACHEFLUSH_H
+
+#include <linux/mm.h>
+#include <abi/cacheflush.h>
+
+#endif /* __ASM_CSKY_CACHEFLUSH_H */
diff --git a/arch/csky/include/asm/checksum.h b/arch/csky/include/asm/checksum.h
new file mode 100644
index 000000000..768582429
--- /dev/null
+++ b/arch/csky/include/asm/checksum.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_CHECKSUM_H
+#define __ASM_CSKY_CHECKSUM_H
+
+#include <linux/in6.h>
+#include <asm/byteorder.h>
+
+static inline __sum16 csum_fold(__wsum csum)
+{
+	u32 tmp;
+
+	asm volatile(
+	"mov	%1, %0\n"
+	"rori	%0, 16\n"
+	"addu	%0, %1\n"
+	"lsri	%0, 16\n"
+	: "=r"(csum), "=r"(tmp)
+	: "0"(csum));
+
+	return (__force __sum16) ~csum;
+}
+#define csum_fold csum_fold
+
+static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
+		unsigned short len, unsigned short proto, __wsum sum)
+{
+	asm volatile(
+	"clrc\n"
+	"addc    %0, %1\n"
+	"addc    %0, %2\n"
+	"addc    %0, %3\n"
+	"inct    %0\n"
+	: "=r"(sum)
+	: "r"((__force u32)saddr), "r"((__force u32)daddr),
+#ifdef __BIG_ENDIAN
+	"r"(proto + len),
+#else
+	"r"((proto + len) << 8),
+#endif
+	"0" ((__force unsigned long)sum)
+	: "cc");
+	return sum;
+}
+#define csum_tcpudp_nofold csum_tcpudp_nofold
+
+#include <asm-generic/checksum.h>
+
+#endif /* __ASM_CSKY_CHECKSUM_H */
diff --git a/arch/csky/include/asm/cmpxchg.h b/arch/csky/include/asm/cmpxchg.h
new file mode 100644
index 000000000..89224530a
--- /dev/null
+++ b/arch/csky/include/asm/cmpxchg.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_CMPXCHG_H
+#define __ASM_CSKY_CMPXCHG_H
+
+#ifdef CONFIG_CPU_HAS_LDSTEX
+#include <asm/barrier.h>
+
+extern void __bad_xchg(void);
+
+#define __xchg(new, ptr, size)					\
+({								\
+	__typeof__(ptr) __ptr = (ptr);				\
+	__typeof__(new) __new = (new);				\
+	__typeof__(*(ptr)) __ret;				\
+	unsigned long tmp;					\
+	switch (size) {						\
+	case 4:							\
+		smp_mb();					\
+		asm volatile (					\
+		"1:	ldex.w		%0, (%3) \n"		\
+		"	mov		%1, %2   \n"		\
+		"	stex.w		%1, (%3) \n"		\
+		"	bez		%1, 1b   \n"		\
+			: "=&r" (__ret), "=&r" (tmp)		\
+			: "r" (__new), "r"(__ptr)		\
+			:);					\
+		smp_mb();					\
+		break;						\
+	default:						\
+		__bad_xchg();					\
+	}							\
+	__ret;							\
+})
+
+#define xchg(ptr, x)	(__xchg((x), (ptr), sizeof(*(ptr))))
+
+#define __cmpxchg(ptr, old, new, size)				\
+({								\
+	__typeof__(ptr) __ptr = (ptr);				\
+	__typeof__(new) __new = (new);				\
+	__typeof__(new) __tmp;					\
+	__typeof__(old) __old = (old);				\
+	__typeof__(*(ptr)) __ret;				\
+	switch (size) {						\
+	case 4:							\
+		smp_mb();					\
+		asm volatile (					\
+		"1:	ldex.w		%0, (%3) \n"		\
+		"	cmpne		%0, %4   \n"		\
+		"	bt		2f       \n"		\
+		"	mov		%1, %2   \n"		\
+		"	stex.w		%1, (%3) \n"		\
+		"	bez		%1, 1b   \n"		\
+		"2:				 \n"		\
+			: "=&r" (__ret), "=&r" (__tmp)		\
+			: "r" (__new), "r"(__ptr), "r"(__old)	\
+			:);					\
+		smp_mb();					\
+		break;						\
+	default:						\
+		__bad_xchg();					\
+	}							\
+	__ret;							\
+})
+
+#define cmpxchg(ptr, o, n) \
+	(__cmpxchg((ptr), (o), (n), sizeof(*(ptr))))
+#else
+#include <asm-generic/cmpxchg.h>
+#endif
+
+#endif /* __ASM_CSKY_CMPXCHG_H */
diff --git a/arch/csky/include/asm/elf.h b/arch/csky/include/asm/elf.h
new file mode 100644
index 000000000..e1ec55827
--- /dev/null
+++ b/arch/csky/include/asm/elf.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_ELF_H
+#define __ASM_CSKY_ELF_H
+
+#include <asm/ptrace.h>
+#include <abi/regdef.h>
+
+#define ELF_ARCH EM_CSKY
+#define EM_CSKY_OLD 39
+
+/* CSKY Relocations */
+#define R_CSKY_NONE               0
+#define R_CSKY_32                 1
+#define R_CSKY_PCIMM8BY4          2
+#define R_CSKY_PCIMM11BY2         3
+#define R_CSKY_PCIMM4BY2          4
+#define R_CSKY_PC32               5
+#define R_CSKY_PCRELJSR_IMM11BY2  6
+#define R_CSKY_GNU_VTINHERIT      7
+#define R_CSKY_GNU_VTENTRY        8
+#define R_CSKY_RELATIVE           9
+#define R_CSKY_COPY               10
+#define R_CSKY_GLOB_DAT           11
+#define R_CSKY_JUMP_SLOT          12
+#define R_CSKY_ADDR_HI16          24
+#define R_CSKY_ADDR_LO16          25
+#define R_CSKY_PCRELJSR_IMM26BY2  40
+
+typedef unsigned long elf_greg_t;
+
+typedef struct user_fp elf_fpregset_t;
+
+/*
+ * In gdb/bfd elf32-csky.c, csky_elf_grok_prstatus() use fixed size of
+ * elf_prstatus. It's 148 for abiv1 and 220 for abiv2, the size is enough
+ * for coredump and no need full sizeof(struct pt_regs).
+ */
+#define ELF_NGREG ((sizeof(struct pt_regs) / sizeof(elf_greg_t)) - 2)
+
+typedef elf_greg_t elf_gregset_t[ELF_NGREG];
+
+/*
+ * This is used to ensure we don't load something for the wrong architecture.
+ */
+#define elf_check_arch(x) (((x)->e_machine == ELF_ARCH) || \
+			   ((x)->e_machine == EM_CSKY_OLD))
+
+/*
+ * These are used to set parameters in the core dumps.
+ */
+#define USE_ELF_CORE_DUMP
+#define ELF_EXEC_PAGESIZE		4096
+#define ELF_CLASS			ELFCLASS32
+#define ELF_PLAT_INIT(_r, load_addr)	{ _r->a0 = 0; }
+
+#ifdef __cskyBE__
+#define ELF_DATA	ELFDATA2MSB
+#else
+#define ELF_DATA	ELFDATA2LSB
+#endif
+
+/*
+ * This is the location that an ET_DYN program is loaded if exec'ed. Typical
+ * use of this is to invoke "./ld.so someprog" to test out a new version of
+ * the loader.  We need to make sure that it is out of the way of the program
+ * that it will "exec", and that there is sufficient room for the brk.
+ */
+#define ELF_ET_DYN_BASE	0x0UL
+#include <abi/elf.h>
+
+/* Similar, but for a thread other than current. */
+struct task_struct;
+extern int dump_task_regs(struct task_struct *tsk, elf_gregset_t *elf_regs);
+#define ELF_CORE_COPY_TASK_REGS(tsk, elf_regs) dump_task_regs(tsk, elf_regs)
+
+#define ELF_HWCAP	(0)
+
+/*
+ * This yields a string that ld.so will use to load implementation specific
+ * libraries for optimization. This is more specific in intent than poking
+ * at uname or /proc/cpuinfo.
+ */
+#define ELF_PLATFORM		(NULL)
+#define SET_PERSONALITY(ex)	set_personality(PER_LINUX)
+
+#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
+struct linux_binprm;
+extern int arch_setup_additional_pages(struct linux_binprm *bprm,
+				       int uses_interp);
+#endif /* __ASM_CSKY_ELF_H */
diff --git a/arch/csky/include/asm/fixmap.h b/arch/csky/include/asm/fixmap.h
new file mode 100644
index 000000000..81f9477d5
--- /dev/null
+++ b/arch/csky/include/asm/fixmap.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_FIXMAP_H
+#define __ASM_CSKY_FIXMAP_H
+
+#include <asm/page.h>
+#include <asm/memory.h>
+#ifdef CONFIG_HIGHMEM
+#include <linux/threads.h>
+#include <asm/kmap_types.h>
+#endif
+
+enum fixed_addresses {
+#ifdef CONFIG_HAVE_TCM
+	FIX_TCM = TCM_NR_PAGES,
+#endif
+#ifdef CONFIG_HIGHMEM
+	FIX_KMAP_BEGIN,
+	FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
+#endif
+	__end_of_fixed_addresses
+};
+
+#define FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
+
+#include <asm-generic/fixmap.h>
+
+extern void fixrange_init(unsigned long start, unsigned long end,
+	pgd_t *pgd_base);
+extern void __init fixaddr_init(void);
+
+#endif /* __ASM_CSKY_FIXMAP_H */
diff --git a/arch/csky/include/asm/ftrace.h b/arch/csky/include/asm/ftrace.h
new file mode 100644
index 000000000..fae72b0b1
--- /dev/null
+++ b/arch/csky/include/asm/ftrace.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_FTRACE_H
+#define __ASM_CSKY_FTRACE_H
+
+#define MCOUNT_INSN_SIZE	14
+
+#define HAVE_FUNCTION_GRAPH_FP_TEST
+
+#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+
+#define ARCH_SUPPORTS_FTRACE_OPS 1
+
+#define MCOUNT_ADDR	((unsigned long)_mcount)
+
+#ifndef __ASSEMBLY__
+
+extern void _mcount(unsigned long);
+
+extern void ftrace_graph_call(void);
+
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+	return addr;
+}
+
+struct dyn_arch_ftrace {
+};
+#endif /* !__ASSEMBLY__ */
+#endif /* __ASM_CSKY_FTRACE_H */
diff --git a/arch/csky/include/asm/highmem.h b/arch/csky/include/asm/highmem.h
new file mode 100644
index 000000000..14645e3d5
--- /dev/null
+++ b/arch/csky/include/asm/highmem.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_HIGHMEM_H
+#define __ASM_CSKY_HIGHMEM_H
+
+#ifdef __KERNEL__
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/uaccess.h>
+#include <asm/kmap_types.h>
+#include <asm/cache.h>
+
+/* undef for production */
+#define HIGHMEM_DEBUG 1
+
+/* declarations for highmem.c */
+extern unsigned long highstart_pfn, highend_pfn;
+
+extern pte_t *pkmap_page_table;
+
+/*
+ * Right now we initialize only a single pte table. It can be extended
+ * easily, subsequent pte tables have to be allocated in one physical
+ * chunk of RAM.
+ */
+#define LAST_PKMAP 1024
+#define LAST_PKMAP_MASK (LAST_PKMAP-1)
+#define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
+#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
+
+#define ARCH_HAS_KMAP_FLUSH_TLB
+extern void kmap_flush_tlb(unsigned long addr);
+extern void *kmap_atomic_pfn(unsigned long pfn);
+
+#define flush_cache_kmaps() do {} while (0)
+
+extern void kmap_init(void);
+
+#endif /* __KERNEL__ */
+
+#endif /* __ASM_CSKY_HIGHMEM_H */
diff --git a/arch/csky/include/asm/io.h b/arch/csky/include/asm/io.h
new file mode 100644
index 000000000..e909587f2
--- /dev/null
+++ b/arch/csky/include/asm/io.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_IO_H
+#define __ASM_CSKY_IO_H
+
+#include <linux/pgtable.h>
+#include <linux/types.h>
+#include <linux/version.h>
+
+/*
+ * I/O memory access primitives. Reads are ordered relative to any
+ * following Normal memory access. Writes are ordered relative to any prior
+ * Normal memory access.
+ *
+ * For CACHEV1 (807, 810), store instruction could fast retire, so we need
+ * another mb() to prevent st fast retire.
+ *
+ * For CACHEV2 (860), store instruction with PAGE_ATTR_NO_BUFFERABLE won't
+ * fast retire.
+ */
+#define readb(c)		({ u8  __v = readb_relaxed(c); rmb(); __v; })
+#define readw(c)		({ u16 __v = readw_relaxed(c); rmb(); __v; })
+#define readl(c)		({ u32 __v = readl_relaxed(c); rmb(); __v; })
+
+#ifdef CONFIG_CPU_HAS_CACHEV2
+#define writeb(v,c)		({ wmb(); writeb_relaxed((v),(c)); })
+#define writew(v,c)		({ wmb(); writew_relaxed((v),(c)); })
+#define writel(v,c)		({ wmb(); writel_relaxed((v),(c)); })
+#else
+#define writeb(v,c)		({ wmb(); writeb_relaxed((v),(c)); mb(); })
+#define writew(v,c)		({ wmb(); writew_relaxed((v),(c)); mb(); })
+#define writel(v,c)		({ wmb(); writel_relaxed((v),(c)); mb(); })
+#endif
+
+/*
+ * I/O memory mapping functions.
+ */
+#define ioremap_wc(addr, size) \
+	ioremap_prot((addr), (size), \
+		(_PAGE_IOREMAP & ~_CACHE_MASK) | _CACHE_UNCACHED)
+
+#include <asm-generic/io.h>
+
+#endif /* __ASM_CSKY_IO_H */
diff --git a/arch/csky/include/asm/irq_work.h b/arch/csky/include/asm/irq_work.h
new file mode 100644
index 000000000..33aaf39d6
--- /dev/null
+++ b/arch/csky/include/asm/irq_work.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_IRQ_WORK_H
+#define __ASM_CSKY_IRQ_WORK_H
+
+static inline bool arch_irq_work_has_interrupt(void)
+{
+	return true;
+}
+extern void arch_irq_work_raise(void);
+#endif /* __ASM_CSKY_IRQ_WORK_H */
diff --git a/arch/csky/include/asm/irqflags.h b/arch/csky/include/asm/irqflags.h
new file mode 100644
index 000000000..9e3a569a5
--- /dev/null
+++ b/arch/csky/include/asm/irqflags.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_IRQFLAGS_H
+#define __ASM_CSKY_IRQFLAGS_H
+#include <abi/reg_ops.h>
+
+static inline unsigned long arch_local_irq_save(void)
+{
+	unsigned long flags;
+
+	flags = mfcr("psr");
+	asm volatile("psrclr ie\n":::"memory");
+	return flags;
+}
+#define arch_local_irq_save arch_local_irq_save
+
+static inline void arch_local_irq_enable(void)
+{
+	asm volatile("psrset ee, ie\n":::"memory");
+}
+#define arch_local_irq_enable arch_local_irq_enable
+
+static inline void arch_local_irq_disable(void)
+{
+	asm volatile("psrclr ie\n":::"memory");
+}
+#define arch_local_irq_disable arch_local_irq_disable
+
+static inline unsigned long arch_local_save_flags(void)
+{
+	return mfcr("psr");
+}
+#define arch_local_save_flags arch_local_save_flags
+
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+	mtcr("psr", flags);
+}
+#define arch_local_irq_restore arch_local_irq_restore
+
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+	return !(flags & (1<<6));
+}
+#define arch_irqs_disabled_flags arch_irqs_disabled_flags
+
+#include <asm-generic/irqflags.h>
+
+#endif /* __ASM_CSKY_IRQFLAGS_H */
diff --git a/arch/csky/include/asm/kprobes.h b/arch/csky/include/asm/kprobes.h
new file mode 100644
index 000000000..b647bbde4
--- /dev/null
+++ b/arch/csky/include/asm/kprobes.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_CSKY_KPROBES_H
+#define __ASM_CSKY_KPROBES_H
+
+#include <asm-generic/kprobes.h>
+
+#ifdef CONFIG_KPROBES
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/percpu.h>
+
+#define __ARCH_WANT_KPROBES_INSN_SLOT
+#define MAX_INSN_SIZE			1
+
+#define flush_insn_slot(p)		do { } while (0)
+#define kretprobe_blacklist_size	0
+
+#include <asm/probes.h>
+
+struct prev_kprobe {
+	struct kprobe *kp;
+	unsigned int status;
+};
+
+/* Single step context for kprobe */
+struct kprobe_step_ctx {
+	unsigned long ss_pending;
+	unsigned long match_addr;
+};
+
+/* per-cpu kprobe control block */
+struct kprobe_ctlblk {
+	unsigned int kprobe_status;
+	unsigned long saved_sr;
+	struct prev_kprobe prev_kprobe;
+	struct kprobe_step_ctx ss_ctx;
+};
+
+void arch_remove_kprobe(struct kprobe *p);
+int kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr);
+int kprobe_breakpoint_handler(struct pt_regs *regs);
+int kprobe_single_step_handler(struct pt_regs *regs);
+void kretprobe_trampoline(void);
+void __kprobes *trampoline_probe_handler(struct pt_regs *regs);
+
+#endif /* CONFIG_KPROBES */
+#endif /* __ASM_CSKY_KPROBES_H */
diff --git a/arch/csky/include/asm/memory.h b/arch/csky/include/asm/memory.h
new file mode 100644
index 000000000..a65c6759f
--- /dev/null
+++ b/arch/csky/include/asm/memory.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_MEMORY_H
+#define __ASM_CSKY_MEMORY_H
+
+#include <linux/compiler.h>
+#include <linux/const.h>
+#include <linux/types.h>
+#include <linux/sizes.h>
+
+#define FIXADDR_TOP	_AC(0xffffc000, UL)
+#define PKMAP_BASE	_AC(0xff800000, UL)
+#define VMALLOC_START	_AC(0xc0008000, UL)
+#define VMALLOC_END	(PKMAP_BASE - (PAGE_SIZE * 2))
+
+#ifdef CONFIG_HAVE_TCM
+#ifdef CONFIG_HAVE_DTCM
+#define TCM_NR_PAGES	(CONFIG_ITCM_NR_PAGES + CONFIG_DTCM_NR_PAGES)
+#else
+#define TCM_NR_PAGES	(CONFIG_ITCM_NR_PAGES)
+#endif
+#define FIXADDR_TCM	_AC(FIXADDR_TOP - (TCM_NR_PAGES * PAGE_SIZE), UL)
+#endif
+
+#endif
diff --git a/arch/csky/include/asm/mmu.h b/arch/csky/include/asm/mmu.h
new file mode 100644
index 000000000..26fbb1d15
--- /dev/null
+++ b/arch/csky/include/asm/mmu.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_MMU_H
+#define __ASM_CSKY_MMU_H
+
+typedef struct {
+	atomic64_t	asid;
+	void *vdso;
+	cpumask_t	icache_stale_mask;
+} mm_context_t;
+
+#endif /* __ASM_CSKY_MMU_H */
diff --git a/arch/csky/include/asm/mmu_context.h b/arch/csky/include/asm/mmu_context.h
new file mode 100644
index 000000000..abdf1f1cb
--- /dev/null
+++ b/arch/csky/include/asm/mmu_context.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_MMU_CONTEXT_H
+#define __ASM_CSKY_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <abi/ckmmu.h>
+
+#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
+	setup_pgd(__pa(pgd), false)
+
+#define TLBMISS_HANDLER_SETUP_PGD_KERNEL(pgd) \
+	setup_pgd(__pa(pgd), true)
+
+#define ASID_MASK		((1 << CONFIG_CPU_ASID_BITS) - 1)
+#define cpu_asid(mm)		(atomic64_read(&mm->context.asid) & ASID_MASK)
+
+#define init_new_context(tsk,mm)	({ atomic64_set(&(mm)->context.asid, 0); 0; })
+#define activate_mm(prev,next)		switch_mm(prev, next, current)
+
+#define destroy_context(mm)		do {} while (0)
+#define enter_lazy_tlb(mm, tsk)		do {} while (0)
+#define deactivate_mm(tsk, mm)		do {} while (0)
+
+void check_and_switch_context(struct mm_struct *mm, unsigned int cpu);
+
+static inline void
+switch_mm(struct mm_struct *prev, struct mm_struct *next,
+	  struct task_struct *tsk)
+{
+	unsigned int cpu = smp_processor_id();
+
+	if (prev != next)
+		check_and_switch_context(next, cpu);
+
+	TLBMISS_HANDLER_SETUP_PGD(next->pgd);
+	write_mmu_entryhi(next->context.asid.counter);
+
+	flush_icache_deferred(next);
+}
+#endif /* __ASM_CSKY_MMU_CONTEXT_H */
diff --git a/arch/csky/include/asm/page.h b/arch/csky/include/asm/page.h
new file mode 100644
index 000000000..16878240e
--- /dev/null
+++ b/arch/csky/include/asm/page.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_PAGE_H
+#define __ASM_CSKY_PAGE_H
+
+#include <asm/setup.h>
+#include <asm/cache.h>
+#include <linux/const.h>
+
+/*
+ * PAGE_SHIFT determines the page size: 4KB
+ */
+#define PAGE_SHIFT	12
+#define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
+#define PAGE_MASK	(~(PAGE_SIZE - 1))
+#define THREAD_SIZE	(PAGE_SIZE * 2)
+#define THREAD_MASK	(~(THREAD_SIZE - 1))
+#define THREAD_SHIFT	(PAGE_SHIFT + 1)
+
+
+/*
+ * For C-SKY "User-space:Kernel-space" is "2GB:2GB" fixed by hardware and there
+ * are two segment registers (MSA0 + MSA1) to mapping 512MB + 512MB physical
+ * address region. We use them mapping kernel 1GB direct-map address area and
+ * for more than 1GB of memory we use highmem.
+ */
+#define PAGE_OFFSET	0x80000000
+#define SSEG_SIZE	0x20000000
+#define LOWMEM_LIMIT	(SSEG_SIZE * 2)
+
+#define PHYS_OFFSET_OFFSET (CONFIG_DRAM_BASE & (SSEG_SIZE - 1))
+
+#ifndef __ASSEMBLY__
+
+#include <linux/pfn.h>
+
+#define virt_to_pfn(kaddr)      (__pa(kaddr) >> PAGE_SHIFT)
+#define pfn_to_virt(pfn)        __va((pfn) << PAGE_SHIFT)
+
+#define virt_addr_valid(kaddr)  ((void *)(kaddr) >= (void *)PAGE_OFFSET && \
+			(void *)(kaddr) < high_memory)
+#define pfn_valid(pfn)		((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
+
+extern void *memset(void *dest, int c, size_t l);
+extern void *memcpy(void *to, const void *from, size_t l);
+
+#define clear_page(page)	memset((page), 0, PAGE_SIZE)
+#define copy_page(to, from)	memcpy((to), (from), PAGE_SIZE)
+
+#define page_to_phys(page)	(page_to_pfn(page) << PAGE_SHIFT)
+#define phys_to_page(paddr)	(pfn_to_page(PFN_DOWN(paddr)))
+
+struct page;
+
+#include <abi/page.h>
+
+struct vm_area_struct;
+
+typedef struct { unsigned long pte_low; } pte_t;
+#define pte_val(x)	((x).pte_low)
+
+typedef struct { unsigned long pgd; } pgd_t;
+typedef struct { unsigned long pgprot; } pgprot_t;
+typedef struct page *pgtable_t;
+
+#define pgd_val(x)	((x).pgd)
+#define pgprot_val(x)	((x).pgprot)
+
+#define ptep_buddy(x)	((pte_t *)((unsigned long)(x) ^ sizeof(pte_t)))
+
+#define __pte(x)	((pte_t) { (x) })
+#define __pgd(x)	((pgd_t) { (x) })
+#define __pgprot(x)	((pgprot_t) { (x) })
+
+extern unsigned long va_pa_offset;
+
+#define ARCH_PFN_OFFSET	PFN_DOWN(va_pa_offset + PHYS_OFFSET_OFFSET)
+
+#define __pa(x)		 ((unsigned long)(x) - PAGE_OFFSET + va_pa_offset)
+#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - va_pa_offset))
+
+#define __pa_symbol(x)	__pa(RELOC_HIDE((unsigned long)(x), 0))
+
+#define MAP_NR(x)	PFN_DOWN((unsigned long)(x) - PAGE_OFFSET - \
+				 PHYS_OFFSET_OFFSET)
+#define virt_to_page(x)	(mem_map + MAP_NR(x))
+
+#define pfn_to_kaddr(x)	__va(PFN_PHYS(x))
+
+#include <asm-generic/memory_model.h>
+#include <asm-generic/getorder.h>
+
+#endif /* !__ASSEMBLY__ */
+#endif /* __ASM_CSKY_PAGE_H */
diff --git a/arch/csky/include/asm/pci.h b/arch/csky/include/asm/pci.h
new file mode 100644
index 000000000..ebc765b1f
--- /dev/null
+++ b/arch/csky/include/asm/pci.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_CSKY_PCI_H
+#define __ASM_CSKY_PCI_H
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/io.h>
+
+#define PCIBIOS_MIN_IO		0
+#define PCIBIOS_MIN_MEM		0
+
+/* C-SKY shim does not initialize PCI bus */
+#define pcibios_assign_all_busses() 1
+
+extern int isa_dma_bridge_buggy;
+
+#ifdef CONFIG_PCI
+static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
+{
+	/* no legacy IRQ on csky */
+	return -ENODEV;
+}
+
+static inline int pci_proc_domain(struct pci_bus *bus)
+{
+	/* always show the domain in /proc */
+	return 1;
+}
+#endif  /* CONFIG_PCI */
+
+#endif  /* __ASM_CSKY_PCI_H */
diff --git a/arch/csky/include/asm/perf_event.h b/arch/csky/include/asm/perf_event.h
new file mode 100644
index 000000000..572093e11
--- /dev/null
+++ b/arch/csky/include/asm/perf_event.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PERF_EVENT_H
+#define __ASM_CSKY_PERF_EVENT_H
+
+#include <abi/regdef.h>
+
+#define perf_arch_fetch_caller_regs(regs, __ip) { \
+	(regs)->pc = (__ip); \
+	regs_fp(regs) = (unsigned long) __builtin_frame_address(0); \
+	asm volatile("mov %0, sp\n":"=r"((regs)->usp)); \
+}
+
+#endif /* __ASM_PERF_EVENT_ELF_H */
diff --git a/arch/csky/include/asm/pgalloc.h b/arch/csky/include/asm/pgalloc.h
new file mode 100644
index 000000000..d58d8146b
--- /dev/null
+++ b/arch/csky/include/asm/pgalloc.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PGALLOC_H
+#define __ASM_CSKY_PGALLOC_H
+
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+
+#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
+#include <asm-generic/pgalloc.h>
+
+static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
+					pte_t *pte)
+{
+	set_pmd(pmd, __pmd(__pa(pte)));
+}
+
+static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
+					pgtable_t pte)
+{
+	set_pmd(pmd, __pmd(__pa(page_address(pte))));
+}
+
+#define pmd_pgtable(pmd) pmd_page(pmd)
+
+extern void pgd_init(unsigned long *p);
+
+static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
+{
+	pte_t *pte;
+	unsigned long i;
+
+	pte = (pte_t *) __get_free_page(GFP_KERNEL);
+	if (!pte)
+		return NULL;
+
+	for (i = 0; i < PAGE_SIZE/sizeof(pte_t); i++)
+		(pte + i)->pte_low = _PAGE_GLOBAL;
+
+	return pte;
+}
+
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+	pgd_t *ret;
+	pgd_t *init;
+
+	ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ORDER);
+	if (ret) {
+		init = pgd_offset(&init_mm, 0UL);
+		pgd_init((unsigned long *)ret);
+		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
+			(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+		/* prevent out of order excute */
+		smp_mb();
+#ifdef CONFIG_CPU_NEED_TLBSYNC
+		dcache_wb_range((unsigned int)ret,
+				(unsigned int)(ret + PTRS_PER_PGD));
+#endif
+	}
+
+	return ret;
+}
+
+#define __pte_free_tlb(tlb, pte, address)		\
+do {							\
+	pgtable_pte_page_dtor(pte);			\
+	tlb_remove_page(tlb, pte);			\
+} while (0)
+
+extern void pagetable_init(void);
+extern void pre_mmu_init(void);
+extern void pre_trap_init(void);
+
+#endif /* __ASM_CSKY_PGALLOC_H */
diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
new file mode 100644
index 000000000..2002cb7f1
--- /dev/null
+++ b/arch/csky/include/asm/pgtable.h
@@ -0,0 +1,278 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PGTABLE_H
+#define __ASM_CSKY_PGTABLE_H
+
+#include <asm/fixmap.h>
+#include <asm/memory.h>
+#include <asm/addrspace.h>
+#include <abi/pgtable-bits.h>
+#include <asm-generic/pgtable-nopmd.h>
+
+#define PGDIR_SHIFT		22
+#define PGDIR_SIZE		(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK		(~(PGDIR_SIZE-1))
+
+#define USER_PTRS_PER_PGD	(0x80000000UL/PGDIR_SIZE)
+#define FIRST_USER_ADDRESS	0UL
+
+/*
+ * C-SKY is two-level paging structure:
+ */
+#define PGD_ORDER	0
+#define PTE_ORDER	0
+
+#define PTRS_PER_PGD	((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
+#define PTRS_PER_PMD	1
+#define PTRS_PER_PTE	((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
+
+#define pte_ERROR(e) \
+	pr_err("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, (e).pte_low)
+#define pgd_ERROR(e) \
+	pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+#define pmd_page(pmd)	(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
+#define pte_clear(mm, addr, ptep)	set_pte((ptep), \
+	(((unsigned int) addr & PAGE_OFFSET) ? __pte(_PAGE_GLOBAL) : __pte(0)))
+#define pte_none(pte)		(!(pte_val(pte) & ~_PAGE_GLOBAL))
+#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
+#define pte_pfn(x)	((unsigned long)((x).pte_low >> PAGE_SHIFT))
+#define pfn_pte(pfn, prot) __pte(((unsigned long long)(pfn) << PAGE_SHIFT) \
+				| pgprot_val(prot))
+
+#define __READABLE	(_PAGE_READ | _PAGE_VALID | _PAGE_ACCESSED)
+#define __WRITEABLE	(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_MODIFIED)
+
+#define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED | \
+			 _CACHE_MASK)
+
+#define __swp_type(x)			(((x).val >> 4) & 0xff)
+#define __swp_offset(x)			((x).val >> 12)
+#define __swp_entry(type, offset)	((swp_entry_t) {((type) << 4) | \
+					((offset) << 12) })
+#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
+
+#define pte_page(x)			pfn_to_page(pte_pfn(x))
+#define __mk_pte(page_nr, pgprot)	__pte(((page_nr) << PAGE_SHIFT) | \
+					pgprot_val(pgprot))
+
+/*
+ * CSKY can't do page protection for execute, and considers that the same like
+ * read. Also, write permissions imply read permissions. This is the closest
+ * we can get by reasonable means..
+ */
+#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _CACHE_CACHED)
+#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
+				_CACHE_CACHED)
+#define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_READ | _CACHE_CACHED)
+#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_READ | _CACHE_CACHED)
+#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
+				_PAGE_GLOBAL | _CACHE_CACHED)
+#define PAGE_USERIO	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
+				_CACHE_CACHED)
+
+#define _PAGE_IOREMAP \
+	(_PAGE_PRESENT | __READABLE | __WRITEABLE | _PAGE_GLOBAL | \
+	 _CACHE_UNCACHED | _PAGE_SO)
+
+#define __P000	PAGE_NONE
+#define __P001	PAGE_READONLY
+#define __P010	PAGE_COPY
+#define __P011	PAGE_COPY
+#define __P100	PAGE_READONLY
+#define __P101	PAGE_READONLY
+#define __P110	PAGE_COPY
+#define __P111	PAGE_COPY
+
+#define __S000	PAGE_NONE
+#define __S001	PAGE_READONLY
+#define __S010	PAGE_SHARED
+#define __S011	PAGE_SHARED
+#define __S100	PAGE_READONLY
+#define __S101	PAGE_READONLY
+#define __S110	PAGE_SHARED
+#define __S111	PAGE_SHARED
+
+extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
+#define ZERO_PAGE(vaddr)	(virt_to_page(empty_zero_page))
+
+extern void load_pgd(unsigned long pg_dir);
+extern pte_t invalid_pte_table[PTRS_PER_PTE];
+
+static inline void set_pte(pte_t *p, pte_t pte)
+{
+	*p = pte;
+#if defined(CONFIG_CPU_NEED_TLBSYNC)
+	dcache_wb_line((u32)p);
+#endif
+	/* prevent out of order excution */
+	smp_mb();
+}
+#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
+
+static inline pte_t *pmd_page_vaddr(pmd_t pmd)
+{
+	unsigned long ptr;
+
+	ptr = pmd_val(pmd);
+
+	return __va(ptr);
+}
+
+#define pmd_phys(pmd) pmd_val(pmd)
+
+static inline void set_pmd(pmd_t *p, pmd_t pmd)
+{
+	*p = pmd;
+#if defined(CONFIG_CPU_NEED_TLBSYNC)
+	dcache_wb_line((u32)p);
+#endif
+	/* prevent specul excute */
+	smp_mb();
+}
+
+
+static inline int pmd_none(pmd_t pmd)
+{
+	return pmd_val(pmd) == __pa(invalid_pte_table);
+}
+
+#define pmd_bad(pmd)	(pmd_val(pmd) & ~PAGE_MASK)
+
+static inline int pmd_present(pmd_t pmd)
+{
+	return (pmd_val(pmd) != __pa(invalid_pte_table));
+}
+
+static inline void pmd_clear(pmd_t *p)
+{
+	pmd_val(*p) = (__pa(invalid_pte_table));
+#if defined(CONFIG_CPU_NEED_TLBSYNC)
+	dcache_wb_line((u32)p);
+#endif
+}
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+static inline int pte_read(pte_t pte)
+{
+	return pte.pte_low & _PAGE_READ;
+}
+
+static inline int pte_write(pte_t pte)
+{
+	return (pte).pte_low & _PAGE_WRITE;
+}
+
+static inline int pte_dirty(pte_t pte)
+{
+	return (pte).pte_low & _PAGE_MODIFIED;
+}
+
+static inline int pte_young(pte_t pte)
+{
+	return (pte).pte_low & _PAGE_ACCESSED;
+}
+
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_DIRTY);
+	return pte;
+}
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_MODIFIED|_PAGE_DIRTY);
+	return pte;
+}
+
+static inline pte_t pte_mkold(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_ACCESSED|_PAGE_VALID);
+	return pte;
+}
+
+static inline pte_t pte_mkwrite(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_WRITE;
+	if (pte_val(pte) & _PAGE_MODIFIED)
+		pte_val(pte) |= _PAGE_DIRTY;
+	return pte;
+}
+
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_MODIFIED;
+	if (pte_val(pte) & _PAGE_WRITE)
+		pte_val(pte) |= _PAGE_DIRTY;
+	return pte;
+}
+
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_ACCESSED;
+	if (pte_val(pte) & _PAGE_READ)
+		pte_val(pte) |= _PAGE_VALID;
+	return pte;
+}
+
+#define __HAVE_PHYS_MEM_ACCESS_PROT
+struct file;
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+				     unsigned long size, pgprot_t vma_prot);
+
+/*
+ * Macro to make mark a page protection value as "uncacheable".  Note
+ * that "protection" is really a misnomer here as the protection value
+ * contains the memory attribute bits, dirty bits, and various other
+ * bits as well.
+ */
+#define pgprot_noncached pgprot_noncached
+
+static inline pgprot_t pgprot_noncached(pgprot_t _prot)
+{
+	unsigned long prot = pgprot_val(_prot);
+
+	prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED | _PAGE_SO;
+
+	return __pgprot(prot);
+}
+
+#define pgprot_writecombine pgprot_writecombine
+static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
+{
+	unsigned long prot = pgprot_val(_prot);
+
+	prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
+
+	return __pgprot(prot);
+}
+
+/*
+ * Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ */
+#define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+	return __pte((pte_val(pte) & _PAGE_CHG_MASK) |
+		     (pgprot_val(newprot)));
+}
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+extern void paging_init(void);
+
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
+		      pte_t *pte);
+
+/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
+#define kern_addr_valid(addr)	(1)
+
+#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \
+	remap_pfn_range(vma, vaddr, pfn, size, prot)
+
+#endif /* __ASM_CSKY_PGTABLE_H */
diff --git a/arch/csky/include/asm/probes.h b/arch/csky/include/asm/probes.h
new file mode 100644
index 000000000..5e526334e
--- /dev/null
+++ b/arch/csky/include/asm/probes.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_PROBES_H
+#define __ASM_CSKY_PROBES_H
+
+typedef u32 probe_opcode_t;
+typedef void (probes_handler_t) (u32 opcode, long addr, struct pt_regs *);
+
+/* architecture specific copy of original instruction */
+struct arch_probe_insn {
+	probe_opcode_t *insn;
+	probes_handler_t *handler;
+	/* restore address after simulation */
+	unsigned long restore;
+};
+
+#ifdef CONFIG_KPROBES
+typedef u32 kprobe_opcode_t;
+struct arch_specific_insn {
+	struct arch_probe_insn api;
+};
+#endif
+
+#endif /* __ASM_CSKY_PROBES_H */
diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h
new file mode 100644
index 000000000..4800f6563
--- /dev/null
+++ b/arch/csky/include/asm/processor.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PROCESSOR_H
+#define __ASM_CSKY_PROCESSOR_H
+
+#include <linux/bitops.h>
+#include <asm/segment.h>
+#include <asm/ptrace.h>
+#include <asm/current.h>
+#include <asm/cache.h>
+#include <abi/reg_ops.h>
+#include <abi/regdef.h>
+#include <abi/switch_context.h>
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+#endif
+
+struct cpuinfo_csky {
+	unsigned long asid_cache;
+} __aligned(SMP_CACHE_BYTES);
+
+extern struct cpuinfo_csky cpu_data[];
+
+/*
+ * User space process size: 2GB. This is hardcoded into a few places,
+ * so don't change it unless you know what you are doing.  TASK_SIZE
+ * for a 64 bit kernel expandable to 8192EB, of which the current CSKY
+ * implementations will "only" be able to use 1TB ...
+ */
+#define TASK_SIZE       0x7fff8000UL
+
+#ifdef __KERNEL__
+#define STACK_TOP       TASK_SIZE
+#define STACK_TOP_MAX   STACK_TOP
+#endif
+
+/* This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
+
+struct thread_struct {
+	unsigned long  sp;        /* kernel stack pointer */
+	unsigned long  trap_no;   /* saved status register */
+
+	/* FPU regs */
+	struct user_fp __aligned(16) user_fp;
+};
+
+#define INIT_THREAD  { \
+	.sp = sizeof(init_stack) + (unsigned long) &init_stack, \
+}
+
+/*
+ * Do necessary setup to start up a newly executed thread.
+ *
+ * pass the data segment into user programs if it exists,
+ * it can't hurt anything as far as I can tell
+ */
+#define start_thread(_regs, _pc, _usp)					\
+do {									\
+	set_fs(USER_DS); /* reads from user space */			\
+	(_regs)->pc = (_pc);						\
+	(_regs)->regs[1] = 0; /* ABIV1 is R7, uClibc_main rtdl arg */	\
+	(_regs)->regs[2] = 0;						\
+	(_regs)->regs[3] = 0; /* ABIV2 is R7, use it? */		\
+	(_regs)->sr &= ~PS_S;						\
+	(_regs)->usp = (_usp);						\
+} while (0)
+
+/* Forward declaration, a strange C thing */
+struct task_struct;
+
+/* Free all resources held by a thread. */
+static inline void release_thread(struct task_struct *dead_task)
+{
+}
+
+/* Prepare to copy thread state - unlazy all lazy status */
+#define prepare_to_copy(tsk)    do { } while (0)
+
+extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
+
+unsigned long get_wchan(struct task_struct *p);
+
+#define KSTK_EIP(tsk)		(task_pt_regs(tsk)->pc)
+#define KSTK_ESP(tsk)		(task_pt_regs(tsk)->usp)
+
+#define task_pt_regs(p) \
+	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
+
+#define cpu_relax() barrier()
+
+#endif /* __ASM_CSKY_PROCESSOR_H */
diff --git a/arch/csky/include/asm/ptrace.h b/arch/csky/include/asm/ptrace.h
new file mode 100644
index 000000000..91ceb1b45
--- /dev/null
+++ b/arch/csky/include/asm/ptrace.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_PTRACE_H
+#define __ASM_CSKY_PTRACE_H
+
+#include <uapi/asm/ptrace.h>
+#include <asm/traps.h>
+#include <linux/types.h>
+#include <linux/compiler.h>
+
+#ifndef __ASSEMBLY__
+
+#define PS_S	0x80000000 /* Supervisor Mode */
+
+#define USR_BKPT	0x1464
+
+#define arch_has_single_step() (1)
+#define current_pt_regs() \
+({ (struct pt_regs *)((char *)current_thread_info() + THREAD_SIZE) - 1; })
+
+#define user_stack_pointer(regs) ((regs)->usp)
+
+#define user_mode(regs) (!((regs)->sr & PS_S))
+#define instruction_pointer(regs) ((regs)->pc)
+#define profile_pc(regs) instruction_pointer(regs)
+#define trap_no(regs) ((regs->sr >> 16) & 0xff)
+
+static inline void instruction_pointer_set(struct pt_regs *regs,
+					   unsigned long val)
+{
+	regs->pc = val;
+}
+
+#if defined(__CSKYABIV2__)
+#define MAX_REG_OFFSET offsetof(struct pt_regs, dcsr)
+#else
+#define MAX_REG_OFFSET offsetof(struct pt_regs, regs[9])
+#endif
+
+static inline bool in_syscall(struct pt_regs const *regs)
+{
+	return ((regs->sr >> 16) & 0xff) == VEC_TRAP0;
+}
+
+static inline void forget_syscall(struct pt_regs *regs)
+{
+	regs->sr &= ~(0xff << 16);
+}
+
+static inline unsigned long regs_return_value(struct pt_regs *regs)
+{
+	return regs->a0;
+}
+
+static inline void regs_set_return_value(struct pt_regs *regs,
+					 unsigned long val)
+{
+	regs->a0 = val;
+}
+
+/* Valid only for Kernel mode traps. */
+static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
+{
+	return regs->usp;
+}
+
+static inline unsigned long frame_pointer(struct pt_regs *regs)
+{
+	return regs->regs[4];
+}
+static inline void frame_pointer_set(struct pt_regs *regs,
+				     unsigned long val)
+{
+	regs->regs[4] = val;
+}
+
+extern int regs_query_register_offset(const char *name);
+extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
+						unsigned int n);
+
+/*
+ * regs_get_register() - get register value from its offset
+ * @regs:      pt_regs from which register value is gotten
+ * @offset:    offset of the register.
+ *
+ * regs_get_register returns the value of a register whose offset from @regs.
+ * The @offset is the offset of the register in struct pt_regs.
+ * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
+ */
+static inline unsigned long regs_get_register(struct pt_regs *regs,
+						unsigned int offset)
+{
+	if (unlikely(offset > MAX_REG_OFFSET))
+		return 0;
+
+	return *(unsigned long *)((unsigned long)regs + offset);
+}
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_CSKY_PTRACE_H */
diff --git a/arch/csky/include/asm/reg_ops.h b/arch/csky/include/asm/reg_ops.h
new file mode 100644
index 000000000..cccf7d525
--- /dev/null
+++ b/arch/csky/include/asm/reg_ops.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_REGS_OPS_H
+#define __ASM_REGS_OPS_H
+
+#define mfcr(reg)		\
+({				\
+	unsigned int tmp;	\
+	asm volatile(		\
+	"mfcr %0, "reg"\n"	\
+	: "=r"(tmp)		\
+	:			\
+	: "memory");		\
+	tmp;			\
+})
+
+#define mtcr(reg, val)		\
+({				\
+	asm volatile(		\
+	"mtcr %0, "reg"\n"	\
+	:			\
+	: "r"(val)		\
+	: "memory");		\
+})
+
+#endif /* __ASM_REGS_OPS_H */
diff --git a/arch/csky/include/asm/segment.h b/arch/csky/include/asm/segment.h
new file mode 100644
index 000000000..79ede9b1a
--- /dev/null
+++ b/arch/csky/include/asm/segment.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SEGMENT_H
+#define __ASM_CSKY_SEGMENT_H
+
+typedef struct {
+	unsigned long seg;
+} mm_segment_t;
+
+#define KERNEL_DS		((mm_segment_t) { 0xFFFFFFFF })
+
+#define USER_DS			((mm_segment_t) { 0x80000000UL })
+#define get_fs()		(current_thread_info()->addr_limit)
+#define set_fs(x)		(current_thread_info()->addr_limit = (x))
+#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
+
+#endif /* __ASM_CSKY_SEGMENT_H */
diff --git a/arch/csky/include/asm/shmparam.h b/arch/csky/include/asm/shmparam.h
new file mode 100644
index 000000000..efafe4c79
--- /dev/null
+++ b/arch/csky/include/asm/shmparam.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SHMPARAM_H
+#define __ASM_CSKY_SHMPARAM_H
+
+#define SHMLBA	(4 * PAGE_SIZE)
+
+#define __ARCH_FORCE_SHMLBA
+
+#endif /* __ASM_CSKY_SHMPARAM_H */
diff --git a/arch/csky/include/asm/smp.h b/arch/csky/include/asm/smp.h
new file mode 100644
index 000000000..668b79ce2
--- /dev/null
+++ b/arch/csky/include/asm/smp.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_SMP_H
+#define __ASM_CSKY_SMP_H
+
+#include <linux/cpumask.h>
+#include <linux/irqreturn.h>
+#include <linux/threads.h>
+
+#ifdef CONFIG_SMP
+
+void __init setup_smp(void);
+
+void __init setup_smp_ipi(void);
+
+void arch_send_call_function_ipi_mask(struct cpumask *mask);
+
+void arch_send_call_function_single_ipi(int cpu);
+
+void __init set_send_ipi(void (*func)(const struct cpumask *mask), int irq);
+
+#define raw_smp_processor_id()	(current_thread_info()->cpu)
+
+int __cpu_disable(void);
+
+void __cpu_die(unsigned int cpu);
+
+#endif /* CONFIG_SMP */
+
+#endif /* __ASM_CSKY_SMP_H */
diff --git a/arch/csky/include/asm/spinlock.h b/arch/csky/include/asm/spinlock.h
new file mode 100644
index 000000000..7cf3f2b34
--- /dev/null
+++ b/arch/csky/include/asm/spinlock.h
@@ -0,0 +1,256 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_SPINLOCK_H
+#define __ASM_CSKY_SPINLOCK_H
+
+#include <linux/spinlock_types.h>
+#include <asm/barrier.h>
+
+#ifdef CONFIG_QUEUED_RWLOCKS
+
+/*
+ * Ticket-based spin-locking.
+ */
+static inline void arch_spin_lock(arch_spinlock_t *lock)
+{
+	arch_spinlock_t lockval;
+	u32 ticket_next = 1 << TICKET_NEXT;
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%2) \n"
+		"	mov		%1, %0	 \n"
+		"	add		%0, %3	 \n"
+		"	stex.w		%0, (%2) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp), "=&r" (lockval)
+		: "r"(p), "r"(ticket_next)
+		: "cc");
+
+	while (lockval.tickets.next != lockval.tickets.owner)
+		lockval.tickets.owner = READ_ONCE(lock->tickets.owner);
+
+	smp_mb();
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t *lock)
+{
+	u32 tmp, contended, res;
+	u32 ticket_next = 1 << TICKET_NEXT;
+	u32 *p = &lock->lock;
+
+	do {
+		asm volatile (
+		"	ldex.w		%0, (%3)   \n"
+		"	movi		%2, 1	   \n"
+		"	rotli		%1, %0, 16 \n"
+		"	cmpne		%1, %0     \n"
+		"	bt		1f         \n"
+		"	movi		%2, 0	   \n"
+		"	add		%0, %0, %4 \n"
+		"	stex.w		%0, (%3)   \n"
+		"1:				   \n"
+		: "=&r" (res), "=&r" (tmp), "=&r" (contended)
+		: "r"(p), "r"(ticket_next)
+		: "cc");
+	} while (!res);
+
+	if (!contended)
+		smp_mb();
+
+	return !contended;
+}
+
+static inline void arch_spin_unlock(arch_spinlock_t *lock)
+{
+	smp_mb();
+	WRITE_ONCE(lock->tickets.owner, lock->tickets.owner + 1);
+}
+
+static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
+{
+	return lock.tickets.owner == lock.tickets.next;
+}
+
+static inline int arch_spin_is_locked(arch_spinlock_t *lock)
+{
+	return !arch_spin_value_unlocked(READ_ONCE(*lock));
+}
+
+static inline int arch_spin_is_contended(arch_spinlock_t *lock)
+{
+	struct __raw_tickets tickets = READ_ONCE(lock->tickets);
+
+	return (tickets.next - tickets.owner) > 1;
+}
+#define arch_spin_is_contended	arch_spin_is_contended
+
+#include <asm/qrwlock.h>
+
+/* See include/linux/spinlock.h */
+#define smp_mb__after_spinlock()	smp_mb()
+
+#else /* CONFIG_QUEUED_RWLOCKS */
+
+/*
+ * Test-and-set spin-locking.
+ */
+static inline void arch_spin_lock(arch_spinlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	bnez		%0, 1b   \n"
+		"	movi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+	smp_mb();
+}
+
+static inline void arch_spin_unlock(arch_spinlock_t *lock)
+{
+	smp_mb();
+	WRITE_ONCE(lock->lock, 0);
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	bnez		%0, 2f   \n"
+		"	movi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		"	movi		%0, 0    \n"
+		"2:				 \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+
+	if (!tmp)
+		smp_mb();
+
+	return !tmp;
+}
+
+#define arch_spin_is_locked(x)	(READ_ONCE((x)->lock) != 0)
+
+/*
+ * read lock/unlock/trylock
+ */
+static inline void arch_read_lock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	blz		%0, 1b   \n"
+		"	addi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+	smp_mb();
+}
+
+static inline void arch_read_unlock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	smp_mb();
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	subi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+}
+
+static inline int arch_read_trylock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	blz		%0, 2f   \n"
+		"	addi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		"	movi		%0, 0    \n"
+		"2:				 \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+
+	if (!tmp)
+		smp_mb();
+
+	return !tmp;
+}
+
+/*
+ * write lock/unlock/trylock
+ */
+static inline void arch_write_lock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	bnez		%0, 1b   \n"
+		"	subi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+	smp_mb();
+}
+
+static inline void arch_write_unlock(arch_rwlock_t *lock)
+{
+	smp_mb();
+	WRITE_ONCE(lock->lock, 0);
+}
+
+static inline int arch_write_trylock(arch_rwlock_t *lock)
+{
+	u32 *p = &lock->lock;
+	u32 tmp;
+
+	asm volatile (
+		"1:	ldex.w		%0, (%1) \n"
+		"	bnez		%0, 2f   \n"
+		"	subi		%0, 1    \n"
+		"	stex.w		%0, (%1) \n"
+		"	bez		%0, 1b   \n"
+		"	movi		%0, 0    \n"
+		"2:				 \n"
+		: "=&r" (tmp)
+		: "r"(p)
+		: "cc");
+
+	if (!tmp)
+		smp_mb();
+
+	return !tmp;
+}
+
+#endif /* CONFIG_QUEUED_RWLOCKS */
+#endif /* __ASM_CSKY_SPINLOCK_H */
diff --git a/arch/csky/include/asm/spinlock_types.h b/arch/csky/include/asm/spinlock_types.h
new file mode 100644
index 000000000..88b82438b
--- /dev/null
+++ b/arch/csky/include/asm/spinlock_types.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_SPINLOCK_TYPES_H
+#define __ASM_CSKY_SPINLOCK_TYPES_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+# error "please don't include this file directly"
+#endif
+
+#define TICKET_NEXT	16
+
+typedef struct {
+	union {
+		u32 lock;
+		struct __raw_tickets {
+			/* little endian */
+			u16 owner;
+			u16 next;
+		} tickets;
+	};
+} arch_spinlock_t;
+
+#define __ARCH_SPIN_LOCK_UNLOCKED	{ { 0 } }
+
+#ifdef CONFIG_QUEUED_RWLOCKS
+#include <asm-generic/qrwlock_types.h>
+
+#else /* CONFIG_NR_CPUS > 2 */
+
+typedef struct {
+	u32 lock;
+} arch_rwlock_t;
+
+#define __ARCH_RW_LOCK_UNLOCKED		{ 0 }
+
+#endif /* CONFIG_QUEUED_RWLOCKS */
+#endif /* __ASM_CSKY_SPINLOCK_TYPES_H */
diff --git a/arch/csky/include/asm/stackprotector.h b/arch/csky/include/asm/stackprotector.h
new file mode 100644
index 000000000..d7cd4e51e
--- /dev/null
+++ b/arch/csky/include/asm/stackprotector.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_STACKPROTECTOR_H
+#define _ASM_STACKPROTECTOR_H 1
+
+#include <linux/random.h>
+#include <linux/version.h>
+
+extern unsigned long __stack_chk_guard;
+
+/*
+ * Initialize the stackprotector canary value.
+ *
+ * NOTE: this must only be called from functions that never return,
+ * and it must always be inlined.
+ */
+static __always_inline void boot_init_stack_canary(void)
+{
+	unsigned long canary;
+
+	/* Try to get a semi random initial value. */
+	get_random_bytes(&canary, sizeof(canary));
+	canary ^= LINUX_VERSION_CODE;
+	canary &= CANARY_MASK;
+
+	current->stack_canary = canary;
+	__stack_chk_guard = current->stack_canary;
+}
+
+#endif /* __ASM_SH_STACKPROTECTOR_H */
diff --git a/arch/csky/include/asm/string.h b/arch/csky/include/asm/string.h
new file mode 100644
index 000000000..73142de18
--- /dev/null
+++ b/arch/csky/include/asm/string.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef _CSKY_STRING_MM_H_
+#define _CSKY_STRING_MM_H_
+
+#ifndef __ASSEMBLY__
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <abi/string.h>
+#endif
+
+#endif /* _CSKY_STRING_MM_H_ */
diff --git a/arch/csky/include/asm/switch_to.h b/arch/csky/include/asm/switch_to.h
new file mode 100644
index 000000000..35a39e889
--- /dev/null
+++ b/arch/csky/include/asm/switch_to.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SWITCH_TO_H
+#define __ASM_CSKY_SWITCH_TO_H
+
+#include <linux/thread_info.h>
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+static inline void __switch_to_fpu(struct task_struct *prev,
+				   struct task_struct *next)
+{
+	save_to_user_fp(&prev->thread.user_fp);
+	restore_from_user_fp(&next->thread.user_fp);
+}
+#else
+static inline void __switch_to_fpu(struct task_struct *prev,
+				   struct task_struct *next)
+{}
+#endif
+
+/*
+ * Context switching is now performed out-of-line in switch_to.S
+ */
+extern struct task_struct *__switch_to(struct task_struct *,
+				       struct task_struct *);
+
+#define switch_to(prev, next, last)					\
+	do {								\
+		struct task_struct *__prev = (prev);			\
+		struct task_struct *__next = (next);			\
+		__switch_to_fpu(__prev, __next);			\
+		((last) = __switch_to((prev), (next)));			\
+	} while (0)
+
+#endif /* __ASM_CSKY_SWITCH_TO_H */
diff --git a/arch/csky/include/asm/syscall.h b/arch/csky/include/asm/syscall.h
new file mode 100644
index 000000000..f624fa3bb
--- /dev/null
+++ b/arch/csky/include/asm/syscall.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_SYSCALL_H
+#define __ASM_SYSCALL_H
+
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <abi/regdef.h>
+#include <uapi/linux/audit.h>
+
+extern void *sys_call_table[];
+
+static inline int
+syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
+{
+	return regs_syscallid(regs);
+}
+
+static inline void
+syscall_set_nr(struct task_struct *task, struct pt_regs *regs,
+	       int sysno)
+{
+	regs_syscallid(regs) = sysno;
+}
+
+static inline void
+syscall_rollback(struct task_struct *task, struct pt_regs *regs)
+{
+	regs->a0 = regs->orig_a0;
+}
+
+static inline long
+syscall_get_error(struct task_struct *task, struct pt_regs *regs)
+{
+	unsigned long error = regs->a0;
+
+	return IS_ERR_VALUE(error) ? error : 0;
+}
+
+static inline long
+syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
+{
+	return regs->a0;
+}
+
+static inline void
+syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
+		int error, long val)
+{
+	regs->a0 = (long) error ?: val;
+}
+
+static inline void
+syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
+		      unsigned long *args)
+{
+	args[0] = regs->orig_a0;
+	args++;
+	memcpy(args, &regs->a1, 5 * sizeof(args[0]));
+}
+
+static inline void
+syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
+		      const unsigned long *args)
+{
+	regs->orig_a0 = args[0];
+	args++;
+	memcpy(&regs->a1, args, 5 * sizeof(regs->a1));
+}
+
+static inline int
+syscall_get_arch(struct task_struct *task)
+{
+	return AUDIT_ARCH_CSKY;
+}
+
+#endif	/* __ASM_SYSCALL_H */
diff --git a/arch/csky/include/asm/syscalls.h b/arch/csky/include/asm/syscalls.h
new file mode 100644
index 000000000..5d48e5e00
--- /dev/null
+++ b/arch/csky/include/asm/syscalls.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SYSCALLS_H
+#define __ASM_CSKY_SYSCALLS_H
+
+#include <asm-generic/syscalls.h>
+
+long sys_cacheflush(void __user *, unsigned long, int);
+
+long sys_set_thread_area(unsigned long addr);
+
+long sys_csky_fadvise64_64(int fd, int advice, loff_t offset, loff_t len);
+
+#endif /* __ASM_CSKY_SYSCALLS_H */
diff --git a/arch/csky/include/asm/tcm.h b/arch/csky/include/asm/tcm.h
new file mode 100644
index 000000000..bd1e662ec
--- /dev/null
+++ b/arch/csky/include/asm/tcm.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_TCM_H
+#define __ASM_CSKY_TCM_H
+
+#ifndef CONFIG_HAVE_TCM
+#error "You should not be including tcm.h unless you have a TCM!"
+#endif
+
+#include <linux/compiler.h>
+
+/* Tag variables with this */
+#define __tcmdata __section(".tcm.data")
+/* Tag constants with this */
+#define __tcmconst __section(".tcm.rodata")
+/* Tag functions inside TCM called from outside TCM with this */
+#define __tcmfunc __section(".tcm.text") noinline
+/* Tag function inside TCM called from inside TCM  with this */
+#define __tcmlocalfunc __section(".tcm.text")
+
+void *tcm_alloc(size_t len);
+void tcm_free(void *addr, size_t len);
+
+#endif
diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h
new file mode 100644
index 000000000..21456a373
--- /dev/null
+++ b/arch/csky/include/asm/thread_info.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef _ASM_CSKY_THREAD_INFO_H
+#define _ASM_CSKY_THREAD_INFO_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/version.h>
+#include <asm/types.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+#include <abi/switch_context.h>
+
+struct thread_info {
+	struct task_struct	*task;
+	void			*dump_exec_domain;
+	unsigned long		flags;
+	int			preempt_count;
+	unsigned long		tp_value;
+	mm_segment_t		addr_limit;
+	struct restart_block	restart_block;
+	struct pt_regs		*regs;
+	unsigned int		cpu;
+};
+
+#define INIT_THREAD_INFO(tsk)			\
+{						\
+	.task		= &tsk,			\
+	.preempt_count  = INIT_PREEMPT_COUNT,	\
+	.addr_limit     = KERNEL_DS,		\
+	.cpu		= 0,			\
+	.restart_block = {			\
+		.fn = do_no_restart_syscall,	\
+	},					\
+}
+
+#define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT)
+
+#define thread_saved_fp(tsk) \
+	((unsigned long)(((struct switch_stack *)(tsk->thread.sp))->r8))
+
+#define thread_saved_sp(tsk) \
+	((unsigned long)(tsk->thread.sp))
+
+#define thread_saved_lr(tsk) \
+	((unsigned long)(((struct switch_stack *)(tsk->thread.sp))->r15))
+
+static inline struct thread_info *current_thread_info(void)
+{
+	unsigned long sp;
+
+	asm volatile("mov %0, sp\n":"=r"(sp));
+
+	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#define TIF_SIGPENDING		0	/* signal pending */
+#define TIF_NOTIFY_RESUME	1       /* callback before returning to user */
+#define TIF_NEED_RESCHED	2	/* rescheduling necessary */
+#define TIF_UPROBE		3	/* uprobe breakpoint or singlestep */
+#define TIF_SYSCALL_TRACE	4	/* syscall trace active */
+#define TIF_SYSCALL_TRACEPOINT	5       /* syscall tracepoint instrumentation */
+#define TIF_SYSCALL_AUDIT	6	/* syscall auditing */
+#define TIF_NOTIFY_SIGNAL	7	/* signal notifications exist */
+#define TIF_POLLING_NRFLAG	16	/* poll_idle() is TIF_NEED_RESCHED */
+#define TIF_MEMDIE		18      /* is terminating due to OOM killer */
+#define TIF_RESTORE_SIGMASK	20	/* restore signal mask in do_signal() */
+#define TIF_SECCOMP		21	/* secure computing */
+
+#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
+#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
+#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
+#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
+#define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
+#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
+#define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
+#define _TIF_UPROBE		(1 << TIF_UPROBE)
+#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
+#define _TIF_MEMDIE		(1 << TIF_MEMDIE)
+#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
+#define _TIF_SECCOMP		(1 << TIF_SECCOMP)
+
+#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
+				 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
+				 _TIF_NOTIFY_SIGNAL)
+
+#define _TIF_SYSCALL_WORK	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
+				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)
+
+#endif	/* _ASM_CSKY_THREAD_INFO_H */
diff --git a/arch/csky/include/asm/tlb.h b/arch/csky/include/asm/tlb.h
new file mode 100644
index 000000000..fdff9b8d7
--- /dev/null
+++ b/arch/csky/include/asm/tlb.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_TLB_H
+#define __ASM_CSKY_TLB_H
+
+#include <asm/cacheflush.h>
+
+#define tlb_start_vma(tlb, vma) \
+	do { \
+		if (!(tlb)->fullmm) \
+			flush_cache_range(vma, (vma)->vm_start, (vma)->vm_end); \
+	}  while (0)
+
+#define tlb_end_vma(tlb, vma) \
+	do { \
+		if (!(tlb)->fullmm) \
+			flush_tlb_range(vma, (vma)->vm_start, (vma)->vm_end); \
+	}  while (0)
+
+#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
+
+#include <asm-generic/tlb.h>
+
+#endif /* __ASM_CSKY_TLB_H */
diff --git a/arch/csky/include/asm/tlbflush.h b/arch/csky/include/asm/tlbflush.h
new file mode 100644
index 000000000..6845b0667
--- /dev/null
+++ b/arch/csky/include/asm/tlbflush.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_TLBFLUSH_H
+#define __ASM_TLBFLUSH_H
+
+/*
+ * TLB flushing:
+ *
+ *  - flush_tlb_all() flushes all processes TLB entries
+ *  - flush_tlb_mm(mm) flushes the specified mm context TLB entries
+ *  - flush_tlb_page(vma, vmaddr) flushes one page
+ *  - flush_tlb_range(vma, start, end) flushes a range of pages
+ *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
+ */
+extern void flush_tlb_all(void);
+extern void flush_tlb_mm(struct mm_struct *mm);
+extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long page);
+extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+			    unsigned long end);
+extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
+
+extern void flush_tlb_one(unsigned long vaddr);
+
+#endif
diff --git a/arch/csky/include/asm/traps.h b/arch/csky/include/asm/traps.h
new file mode 100644
index 000000000..1c081805b
--- /dev/null
+++ b/arch/csky/include/asm/traps.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_TRAPS_H
+#define __ASM_CSKY_TRAPS_H
+
+#define VEC_RESET	0
+#define VEC_ALIGN	1
+#define VEC_ACCESS	2
+#define VEC_ZERODIV	3
+#define VEC_ILLEGAL	4
+#define VEC_PRIV	5
+#define VEC_TRACE	6
+#define VEC_BREAKPOINT	7
+#define VEC_UNRECOVER	8
+#define VEC_SOFTRESET	9
+#define VEC_AUTOVEC	10
+#define VEC_FAUTOVEC	11
+#define VEC_HWACCEL	12
+
+#define	VEC_TLBMISS	14
+#define	VEC_TLBMODIFIED	15
+
+#define VEC_TRAP0	16
+#define VEC_TRAP1	17
+#define VEC_TRAP2	18
+#define VEC_TRAP3	19
+
+#define	VEC_TLBINVALIDL	20
+#define	VEC_TLBINVALIDS	21
+
+#define VEC_PRFL	29
+#define VEC_FPE		30
+
+extern void *vec_base[];
+
+#define VEC_INIT(i, func) \
+do { \
+	vec_base[i] = (void *)func; \
+} while (0)
+
+void csky_alignment(struct pt_regs *regs);
+
+#endif /* __ASM_CSKY_TRAPS_H */
diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h
new file mode 100644
index 000000000..1633ffe5a
--- /dev/null
+++ b/arch/csky/include/asm/uaccess.h
@@ -0,0 +1,410 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_UACCESS_H
+#define __ASM_CSKY_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/version.h>
+#include <asm/segment.h>
+
+static inline int access_ok(const void *addr, unsigned long size)
+{
+	unsigned long limit = current_thread_info()->addr_limit.seg;
+
+	return (((unsigned long)addr < limit) &&
+		((unsigned long)(addr + size) < limit));
+}
+
+#define __addr_ok(addr) (access_ok(addr, 0))
+
+extern int __put_user_bad(void);
+
+/*
+ * Tell gcc we read from memory instead of writing: this is because
+ * we do not write to any memory gcc knows about, so there are no
+ * aliasing issues.
+ */
+
+/*
+ * These are the main single-value transfer routines.  They automatically
+ * use the right size if we just have the right pointer type.
+ *
+ * This gets kind of ugly. We want to return _two_ values in "get_user()"
+ * and yet we don't want to do any pointers, because that is too much
+ * of a performance impact. Thus we have a few rather ugly macros here,
+ * and hide all the ugliness from the user.
+ *
+ * The "__xxx" versions of the user access functions are versions that
+ * do not verify the address space, that must have been done previously
+ * with a separate "access_ok()" call (this is used when we do multiple
+ * accesses to the same area of user memory).
+ *
+ * As we use the same address space for kernel and user data on
+ * Ckcore, we can just do these as direct assignments.  (Of course, the
+ * exception handling means that it's no longer "just"...)
+ */
+
+#define put_user(x, ptr) \
+	__put_user_check((x), (ptr), sizeof(*(ptr)))
+
+#define __put_user(x, ptr) \
+	__put_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+#define __ptr(x) ((unsigned long *)(x))
+
+#define get_user(x, ptr) \
+	__get_user_check((x), (ptr), sizeof(*(ptr)))
+
+#define __get_user(x, ptr) \
+	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+#define __put_user_nocheck(x, ptr, size)				\
+({									\
+	long __pu_err = 0;						\
+	typeof(*(ptr)) *__pu_addr = (ptr);				\
+	typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x);			\
+	if (__pu_addr)							\
+		__put_user_size(__pu_val, (__pu_addr), (size),		\
+				__pu_err);				\
+	__pu_err;							\
+})
+
+#define __put_user_check(x, ptr, size)					\
+({									\
+	long __pu_err = -EFAULT;					\
+	typeof(*(ptr)) *__pu_addr = (ptr);				\
+	typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x);			\
+	if (access_ok(__pu_addr, size) && __pu_addr)	\
+		__put_user_size(__pu_val, __pu_addr, (size), __pu_err);	\
+	__pu_err;							\
+})
+
+#define __put_user_size(x, ptr, size, retval)		\
+do {							\
+	retval = 0;					\
+	switch (size) {                                 \
+	case 1:						\
+		__put_user_asm_b(x, ptr, retval);	\
+		break;					\
+	case 2:						\
+		__put_user_asm_h(x, ptr, retval);	\
+		break;					\
+	case 4:						\
+		__put_user_asm_w(x, ptr, retval);	\
+		break;					\
+	case 8:						\
+		__put_user_asm_64(x, ptr, retval);	\
+		break;					\
+	default:					\
+		__put_user_bad();			\
+	}	                                        \
+} while (0)
+
+/*
+ * We don't tell gcc that we are accessing memory, but this is OK
+ * because we do not write to any memory gcc knows about, so there
+ * are no aliasing issues.
+ *
+ * Note that PC at a fault is the address *after* the faulting
+ * instruction.
+ */
+#define __put_user_asm_b(x, ptr, err)			\
+do {							\
+	int errcode;					\
+	asm volatile(					\
+	"1:     stb   %1, (%2,0)	\n"		\
+	"       br    3f		\n"		\
+	"2:     mov   %0, %3		\n"		\
+	"       br    3f		\n"		\
+	".section __ex_table, \"a\"	\n"		\
+	".align   2			\n"		\
+	".long    1b,2b			\n"		\
+	".previous			\n"		\
+	"3:				\n"		\
+	: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)	\
+	: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)	\
+	: "memory");					\
+} while (0)
+
+#define __put_user_asm_h(x, ptr, err)			\
+do {							\
+	int errcode;					\
+	asm volatile(					\
+	"1:     sth   %1, (%2,0)	\n"		\
+	"       br    3f		\n"		\
+	"2:     mov   %0, %3		\n"		\
+	"       br    3f		\n"		\
+	".section __ex_table, \"a\"	\n"		\
+	".align   2			\n"		\
+	".long    1b,2b			\n"		\
+	".previous			\n"		\
+	"3:				\n"		\
+	: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)	\
+	: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)	\
+	: "memory");					\
+} while (0)
+
+#define __put_user_asm_w(x, ptr, err)			\
+do {							\
+	int errcode;					\
+	asm volatile(					\
+	"1:     stw   %1, (%2,0)	\n"		\
+	"       br    3f		\n"		\
+	"2:     mov   %0, %3		\n"		\
+	"       br    3f		\n"		\
+	".section __ex_table,\"a\"	\n"		\
+	".align   2			\n"		\
+	".long    1b, 2b		\n"		\
+	".previous			\n"		\
+	"3:				\n"		\
+	: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode)	\
+	: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT)	\
+	: "memory");					\
+} while (0)
+
+#define __put_user_asm_64(x, ptr, err)				\
+do {								\
+	int tmp;						\
+	int errcode;						\
+	typeof(*(ptr))src = (typeof(*(ptr)))x;			\
+	typeof(*(ptr))*psrc = &src;				\
+								\
+	asm volatile(						\
+	"     ldw     %3, (%1, 0)     \n"			\
+	"1:   stw     %3, (%2, 0)     \n"			\
+	"     ldw     %3, (%1, 4)     \n"			\
+	"2:   stw     %3, (%2, 4)     \n"			\
+	"     br      4f              \n"			\
+	"3:   mov     %0, %4          \n"			\
+	"     br      4f              \n"			\
+	".section __ex_table, \"a\"   \n"			\
+	".align   2                   \n"			\
+	".long    1b, 3b              \n"			\
+	".long    2b, 3b              \n"			\
+	".previous                    \n"			\
+	"4:                           \n"			\
+	: "=r"(err), "=r"(psrc), "=r"(ptr),			\
+	  "=r"(tmp), "=r"(errcode)				\
+	: "0"(err), "1"(psrc), "2"(ptr), "3"(0), "4"(-EFAULT)	\
+	: "memory");						\
+} while (0)
+
+#define __get_user_nocheck(x, ptr, size)			\
+({								\
+	long  __gu_err;						\
+	__get_user_size(x, (ptr), (size), __gu_err);		\
+	__gu_err;						\
+})
+
+#define __get_user_check(x, ptr, size)				\
+({								\
+	int __gu_err = -EFAULT;					\
+	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);	\
+	if (access_ok(__gu_ptr, size) && __gu_ptr)	\
+		__get_user_size(x, __gu_ptr, size, __gu_err);	\
+	__gu_err;						\
+})
+
+#define __get_user_size(x, ptr, size, retval)			\
+do {								\
+	switch (size) {						\
+	case 1:							\
+		__get_user_asm_common((x), ptr, "ldb", retval);	\
+		break;						\
+	case 2:							\
+		__get_user_asm_common((x), ptr, "ldh", retval);	\
+		break;						\
+	case 4:							\
+		__get_user_asm_common((x), ptr, "ldw", retval);	\
+		break;						\
+	default:						\
+		x = 0;						\
+		(retval) = __get_user_bad();			\
+	}							\
+} while (0)
+
+#define __get_user_asm_common(x, ptr, ins, err)			\
+do {								\
+	int errcode;						\
+	asm volatile(						\
+	"1:   " ins " %1, (%4,0)	\n"			\
+	"       br    3f		\n"			\
+	/* Fix up codes */					\
+	"2:     mov   %0, %2		\n"			\
+	"       movi  %1, 0		\n"			\
+	"       br    3f		\n"			\
+	".section __ex_table,\"a\"      \n"			\
+	".align   2			\n"			\
+	".long    1b, 2b		\n"			\
+	".previous			\n"			\
+	"3:				\n" 			\
+	: "=r"(err), "=r"(x), "=r"(errcode)			\
+	: "0"(0), "r"(ptr), "2"(-EFAULT)			\
+	: "memory");						\
+} while (0)
+
+extern int __get_user_bad(void);
+
+#define ___copy_to_user(to, from, n)			\
+do {							\
+	int w0, w1, w2, w3;				\
+	asm volatile(					\
+	"0:     cmpnei  %1, 0           \n"		\
+	"       bf      8f              \n"		\
+	"       mov     %3, %1          \n"		\
+	"       or      %3, %2          \n"		\
+	"       andi    %3, 3           \n"		\
+	"       cmpnei  %3, 0           \n"		\
+	"       bf      1f              \n"		\
+	"       br      5f              \n"		\
+	"1:     cmplti  %0, 16          \n" /* 4W */	\
+	"       bt      3f              \n"		\
+	"       ldw     %3, (%2, 0)     \n"		\
+	"       ldw     %4, (%2, 4)     \n"		\
+	"       ldw     %5, (%2, 8)     \n"		\
+	"       ldw     %6, (%2, 12)    \n"		\
+	"2:     stw     %3, (%1, 0)     \n"		\
+	"9:     stw     %4, (%1, 4)     \n"		\
+	"10:    stw     %5, (%1, 8)     \n"		\
+	"11:    stw     %6, (%1, 12)    \n"		\
+	"       addi    %2, 16          \n"		\
+	"       addi    %1, 16          \n"		\
+	"       subi    %0, 16          \n"		\
+	"       br      1b              \n"		\
+	"3:     cmplti  %0, 4           \n" /* 1W */	\
+	"       bt      5f              \n"		\
+	"       ldw     %3, (%2, 0)     \n"		\
+	"4:     stw     %3, (%1, 0)     \n"		\
+	"       addi    %2, 4           \n"		\
+	"       addi    %1, 4           \n"		\
+	"       subi    %0, 4           \n"		\
+	"       br      3b              \n"		\
+	"5:     cmpnei  %0, 0           \n"  /* 1B */   \
+	"       bf      13f             \n"		\
+	"       ldb     %3, (%2, 0)     \n"		\
+	"6:     stb     %3, (%1, 0)     \n"		\
+	"       addi    %2,  1          \n"		\
+	"       addi    %1,  1          \n"		\
+	"       subi    %0,  1          \n"		\
+	"       br      5b              \n"		\
+	"7:     subi	%0,  4          \n"		\
+	"8:     subi	%0,  4          \n"		\
+	"12:    subi	%0,  4          \n"		\
+	"       br      13f             \n"		\
+	".section __ex_table, \"a\"     \n"		\
+	".align   2                     \n"		\
+	".long    2b, 13f               \n"		\
+	".long    4b, 13f               \n"		\
+	".long    6b, 13f               \n"		\
+	".long    9b, 12b               \n"		\
+	".long   10b, 8b                \n"		\
+	".long   11b, 7b                \n"		\
+	".previous                      \n"		\
+	"13:                            \n"		\
+	: "=r"(n), "=r"(to), "=r"(from), "=r"(w0),	\
+	  "=r"(w1), "=r"(w2), "=r"(w3)			\
+	: "0"(n), "1"(to), "2"(from)			\
+	: "memory");					\
+} while (0)
+
+#define ___copy_from_user(to, from, n)			\
+do {							\
+	int tmp;					\
+	int nsave;					\
+	asm volatile(					\
+	"0:     cmpnei  %1, 0           \n"		\
+	"       bf      7f              \n"		\
+	"       mov     %3, %1          \n"		\
+	"       or      %3, %2          \n"		\
+	"       andi    %3, 3           \n"		\
+	"       cmpnei  %3, 0           \n"		\
+	"       bf      1f              \n"		\
+	"       br      5f              \n"		\
+	"1:     cmplti  %0, 16          \n"		\
+	"       bt      3f              \n"		\
+	"2:     ldw     %3, (%2, 0)     \n"		\
+	"10:    ldw     %4, (%2, 4)     \n"		\
+	"       stw     %3, (%1, 0)     \n"		\
+	"       stw     %4, (%1, 4)     \n"		\
+	"11:    ldw     %3, (%2, 8)     \n"		\
+	"12:    ldw     %4, (%2, 12)    \n"		\
+	"       stw     %3, (%1, 8)     \n"		\
+	"       stw     %4, (%1, 12)    \n"		\
+	"       addi    %2, 16          \n"		\
+	"       addi    %1, 16          \n"		\
+	"       subi    %0, 16          \n"		\
+	"       br      1b              \n"		\
+	"3:     cmplti  %0, 4           \n"		\
+	"       bt      5f              \n"		\
+	"4:     ldw     %3, (%2, 0)     \n"		\
+	"       stw     %3, (%1, 0)     \n"		\
+	"       addi    %2, 4           \n"		\
+	"       addi    %1, 4           \n"		\
+	"       subi    %0, 4           \n"		\
+	"       br      3b              \n"		\
+	"5:     cmpnei  %0, 0           \n"		\
+	"       bf      7f              \n"		\
+	"6:     ldb     %3, (%2, 0)     \n"		\
+	"       stb     %3, (%1, 0)     \n"		\
+	"       addi    %2,  1          \n"		\
+	"       addi    %1,  1          \n"		\
+	"       subi    %0,  1          \n"		\
+	"       br      5b              \n"		\
+	"8:     stw     %3, (%1, 0)     \n"		\
+	"       subi    %0, 4           \n"		\
+	"       bf      7f              \n"		\
+	"9:     subi    %0, 8           \n"		\
+	"       bf      7f              \n"		\
+	"13:    stw     %3, (%1, 8)     \n"		\
+	"       subi    %0, 12          \n"		\
+	"       bf      7f              \n"		\
+	".section __ex_table, \"a\"     \n"		\
+	".align   2                     \n"		\
+	".long    2b, 7f                \n"		\
+	".long    4b, 7f                \n"		\
+	".long    6b, 7f                \n"		\
+	".long   10b, 8b                \n"		\
+	".long   11b, 9b                \n"		\
+	".long   12b,13b                \n"		\
+	".previous                      \n"		\
+	"7:                             \n"		\
+	: "=r"(n), "=r"(to), "=r"(from), "=r"(nsave),	\
+	  "=r"(tmp)					\
+	: "0"(n), "1"(to), "2"(from)			\
+	: "memory");					\
+} while (0)
+
+unsigned long raw_copy_from_user(void *to, const void *from, unsigned long n);
+unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n);
+
+unsigned long clear_user(void *to, unsigned long n);
+unsigned long __clear_user(void __user *to, unsigned long n);
+
+long strncpy_from_user(char *dst, const char *src, long count);
+long __strncpy_from_user(char *dst, const char *src, long count);
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 on exception, a value greater than N if too long
+ */
+long strnlen_user(const char *src, long n);
+
+#define strlen_user(str) strnlen_user(str, 32767)
+
+struct exception_table_entry {
+	unsigned long insn;
+	unsigned long nextinsn;
+};
+
+extern int fixup_exception(struct pt_regs *regs);
+
+#endif /* __ASM_CSKY_UACCESS_H */
diff --git a/arch/csky/include/asm/unistd.h b/arch/csky/include/asm/unistd.h
new file mode 100644
index 000000000..da7a18295
--- /dev/null
+++ b/arch/csky/include/asm/unistd.h
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <uapi/asm/unistd.h>
+
+#define NR_syscalls (__NR_syscalls)
diff --git a/arch/csky/include/asm/uprobes.h b/arch/csky/include/asm/uprobes.h
new file mode 100644
index 000000000..600388eb9
--- /dev/null
+++ b/arch/csky/include/asm/uprobes.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_CSKY_UPROBES_H
+#define __ASM_CSKY_UPROBES_H
+
+#include <asm/probes.h>
+
+#define MAX_UINSN_BYTES		4
+
+#define UPROBE_SWBP_INSN	USR_BKPT
+#define UPROBE_SWBP_INSN_SIZE	2
+#define UPROBE_XOL_SLOT_BYTES	MAX_UINSN_BYTES
+
+typedef u32 uprobe_opcode_t;
+
+struct arch_uprobe_task {
+	unsigned long   saved_trap_no;
+};
+
+struct arch_uprobe {
+	union {
+		u8 insn[MAX_UINSN_BYTES];
+		u8 ixol[MAX_UINSN_BYTES];
+	};
+	struct arch_probe_insn api;
+	unsigned long insn_size;
+	bool simulate;
+};
+
+int uprobe_breakpoint_handler(struct pt_regs *regs);
+int uprobe_single_step_handler(struct pt_regs *regs);
+
+#endif /* __ASM_CSKY_UPROBES_H */
diff --git a/arch/csky/include/asm/vdso.h b/arch/csky/include/asm/vdso.h
new file mode 100644
index 000000000..d963d691f
--- /dev/null
+++ b/arch/csky/include/asm/vdso.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_CSKY_VDSO_H
+#define __ASM_CSKY_VDSO_H
+
+#include <abi/vdso.h>
+
+struct csky_vdso {
+	unsigned short rt_signal_retcode[4];
+};
+
+#endif /* __ASM_CSKY_VDSO_H */
diff --git a/arch/csky/include/asm/vmalloc.h b/arch/csky/include/asm/vmalloc.h
new file mode 100644
index 000000000..43dca6336
--- /dev/null
+++ b/arch/csky/include/asm/vmalloc.h
@@ -0,0 +1,4 @@
+#ifndef _ASM_CSKY_VMALLOC_H
+#define _ASM_CSKY_VMALLOC_H
+
+#endif /* _ASM_CSKY_VMALLOC_H */
diff --git a/arch/csky/include/uapi/asm/Kbuild b/arch/csky/include/uapi/asm/Kbuild
new file mode 100644
index 000000000..e78470141
--- /dev/null
+++ b/arch/csky/include/uapi/asm/Kbuild
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+generic-y += ucontext.h
diff --git a/arch/csky/include/uapi/asm/byteorder.h b/arch/csky/include/uapi/asm/byteorder.h
new file mode 100644
index 000000000..d150cd664
--- /dev/null
+++ b/arch/csky/include/uapi/asm/byteorder.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_BYTEORDER_H
+#define __ASM_CSKY_BYTEORDER_H
+
+#include <linux/byteorder/little_endian.h>
+
+#endif /* __ASM_CSKY_BYTEORDER_H */
diff --git a/arch/csky/include/uapi/asm/cachectl.h b/arch/csky/include/uapi/asm/cachectl.h
new file mode 100644
index 000000000..ed7fad1ea
--- /dev/null
+++ b/arch/csky/include/uapi/asm/cachectl.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+
+#ifndef __ASM_CSKY_CACHECTL_H
+#define __ASM_CSKY_CACHECTL_H
+
+/*
+ * See "man cacheflush"
+ */
+#define ICACHE  (1<<0)
+#define DCACHE  (1<<1)
+#define BCACHE  (ICACHE|DCACHE)
+
+#endif /* __ASM_CSKY_CACHECTL_H */
diff --git a/arch/csky/include/uapi/asm/perf_regs.h b/arch/csky/include/uapi/asm/perf_regs.h
new file mode 100644
index 000000000..49d4e147a
--- /dev/null
+++ b/arch/csky/include/uapi/asm/perf_regs.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+// Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef _ASM_CSKY_PERF_REGS_H
+#define _ASM_CSKY_PERF_REGS_H
+
+/* Index of struct pt_regs */
+enum perf_event_csky_regs {
+	PERF_REG_CSKY_TLS,
+	PERF_REG_CSKY_LR,
+	PERF_REG_CSKY_PC,
+	PERF_REG_CSKY_SR,
+	PERF_REG_CSKY_SP,
+	PERF_REG_CSKY_ORIG_A0,
+	PERF_REG_CSKY_A0,
+	PERF_REG_CSKY_A1,
+	PERF_REG_CSKY_A2,
+	PERF_REG_CSKY_A3,
+	PERF_REG_CSKY_REGS0,
+	PERF_REG_CSKY_REGS1,
+	PERF_REG_CSKY_REGS2,
+	PERF_REG_CSKY_REGS3,
+	PERF_REG_CSKY_REGS4,
+	PERF_REG_CSKY_REGS5,
+	PERF_REG_CSKY_REGS6,
+	PERF_REG_CSKY_REGS7,
+	PERF_REG_CSKY_REGS8,
+	PERF_REG_CSKY_REGS9,
+#if defined(__CSKYABIV2__)
+	PERF_REG_CSKY_EXREGS0,
+	PERF_REG_CSKY_EXREGS1,
+	PERF_REG_CSKY_EXREGS2,
+	PERF_REG_CSKY_EXREGS3,
+	PERF_REG_CSKY_EXREGS4,
+	PERF_REG_CSKY_EXREGS5,
+	PERF_REG_CSKY_EXREGS6,
+	PERF_REG_CSKY_EXREGS7,
+	PERF_REG_CSKY_EXREGS8,
+	PERF_REG_CSKY_EXREGS9,
+	PERF_REG_CSKY_EXREGS10,
+	PERF_REG_CSKY_EXREGS11,
+	PERF_REG_CSKY_EXREGS12,
+	PERF_REG_CSKY_EXREGS13,
+	PERF_REG_CSKY_EXREGS14,
+	PERF_REG_CSKY_HI,
+	PERF_REG_CSKY_LO,
+	PERF_REG_CSKY_DCSR,
+#endif
+	PERF_REG_CSKY_MAX,
+};
+#endif /* _ASM_CSKY_PERF_REGS_H */
diff --git a/arch/csky/include/uapi/asm/ptrace.h b/arch/csky/include/uapi/asm/ptrace.h
new file mode 100644
index 000000000..66b2268e3
--- /dev/null
+++ b/arch/csky/include/uapi/asm/ptrace.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef _CSKY_PTRACE_H
+#define _CSKY_PTRACE_H
+
+#ifndef __ASSEMBLY__
+
+struct pt_regs {
+	unsigned long	tls;
+	unsigned long	lr;
+	unsigned long	pc;
+	unsigned long	sr;
+	unsigned long	usp;
+
+	/*
+	 * a0, a1, a2, a3:
+	 * abiv1: r2, r3, r4, r5
+	 * abiv2: r0, r1, r2, r3
+	 */
+	unsigned long	orig_a0;
+	unsigned long	a0;
+	unsigned long	a1;
+	unsigned long	a2;
+	unsigned long	a3;
+
+	/*
+	 * ABIV2: r4 ~ r13
+	 * ABIV1: r6 ~ r14, r1
+	 */
+	unsigned long	regs[10];
+
+#if defined(__CSKYABIV2__)
+	/* r16 ~ r30 */
+	unsigned long	exregs[15];
+
+	unsigned long	rhi;
+	unsigned long	rlo;
+	unsigned long	dcsr;
+#endif
+};
+
+struct user_fp {
+	unsigned long	vr[96];
+	unsigned long	fcr;
+	unsigned long	fesr;
+	unsigned long	fid;
+	unsigned long	reserved;
+};
+
+#endif /* __ASSEMBLY__ */
+#endif /* _CSKY_PTRACE_H */
diff --git a/arch/csky/include/uapi/asm/sigcontext.h b/arch/csky/include/uapi/asm/sigcontext.h
new file mode 100644
index 000000000..670c020f2
--- /dev/null
+++ b/arch/csky/include/uapi/asm/sigcontext.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_SIGCONTEXT_H
+#define __ASM_CSKY_SIGCONTEXT_H
+
+#include <asm/ptrace.h>
+
+struct sigcontext {
+	struct pt_regs	sc_pt_regs;
+	struct user_fp	sc_user_fp;
+};
+
+#endif /* __ASM_CSKY_SIGCONTEXT_H */
diff --git a/arch/csky/include/uapi/asm/unistd.h b/arch/csky/include/uapi/asm/unistd.h
new file mode 100644
index 000000000..ba4018929
--- /dev/null
+++ b/arch/csky/include/uapi/asm/unistd.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#define __ARCH_WANT_STAT64
+#define __ARCH_WANT_NEW_STAT
+#define __ARCH_WANT_SYS_CLONE
+#define __ARCH_WANT_SYS_CLONE3
+#define __ARCH_WANT_SET_GET_RLIMIT
+#define __ARCH_WANT_TIME32_SYSCALLS
+#include <asm-generic/unistd.h>
+
+#define __NR_set_thread_area	(__NR_arch_specific_syscall + 0)
+__SYSCALL(__NR_set_thread_area, sys_set_thread_area)
+#define __NR_cacheflush		(__NR_arch_specific_syscall + 1)
+__SYSCALL(__NR_cacheflush, sys_cacheflush)
diff --git a/arch/csky/kernel/Makefile b/arch/csky/kernel/Makefile
new file mode 100644
index 000000000..37f37c0e9
--- /dev/null
+++ b/arch/csky/kernel/Makefile
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0-only
+extra-y := head.o vmlinux.lds
+
+obj-y += entry.o atomic.o signal.o traps.o irq.o time.o vdso.o
+obj-y += power.o syscall.o syscall_table.o setup.o
+obj-y += process.o cpu-probe.o ptrace.o stacktrace.o
+obj-y += probes/
+
+obj-$(CONFIG_MODULES)			+= module.o
+obj-$(CONFIG_SMP)			+= smp.o
+obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace.o
+obj-$(CONFIG_STACKTRACE)		+= stacktrace.o
+obj-$(CONFIG_CSKY_PMU_V1)		+= perf_event.o
+obj-$(CONFIG_PERF_EVENTS)		+= perf_callchain.o
+obj-$(CONFIG_HAVE_PERF_REGS)            += perf_regs.o
+
+ifdef CONFIG_FUNCTION_TRACER
+CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
+endif
diff --git a/arch/csky/kernel/asm-offsets.c b/arch/csky/kernel/asm-offsets.c
new file mode 100644
index 000000000..17479860d
--- /dev/null
+++ b/arch/csky/kernel/asm-offsets.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+#include <linux/kbuild.h>
+#include <abi/regdef.h>
+
+int main(void)
+{
+	/* offsets into the task struct */
+	DEFINE(TASK_STATE,        offsetof(struct task_struct, state));
+	DEFINE(TASK_THREAD_INFO,  offsetof(struct task_struct, stack));
+	DEFINE(TASK_FLAGS,        offsetof(struct task_struct, flags));
+	DEFINE(TASK_PTRACE,       offsetof(struct task_struct, ptrace));
+	DEFINE(TASK_THREAD,       offsetof(struct task_struct, thread));
+	DEFINE(TASK_MM,           offsetof(struct task_struct, mm));
+	DEFINE(TASK_ACTIVE_MM,    offsetof(struct task_struct, active_mm));
+
+	/* offsets into the thread struct */
+	DEFINE(THREAD_KSP,        offsetof(struct thread_struct, sp));
+	DEFINE(THREAD_FESR,       offsetof(struct thread_struct, user_fp.fesr));
+	DEFINE(THREAD_FCR,        offsetof(struct thread_struct, user_fp.fcr));
+	DEFINE(THREAD_FPREG,      offsetof(struct thread_struct, user_fp.vr));
+
+	/* offsets into the thread_info struct */
+	DEFINE(TINFO_FLAGS,       offsetof(struct thread_info, flags));
+	DEFINE(TINFO_PREEMPT,     offsetof(struct thread_info, preempt_count));
+	DEFINE(TINFO_ADDR_LIMIT,  offsetof(struct thread_info, addr_limit));
+	DEFINE(TINFO_TP_VALUE,   offsetof(struct thread_info, tp_value));
+	DEFINE(TINFO_TASK,        offsetof(struct thread_info, task));
+
+	/* offsets into the pt_regs */
+	DEFINE(PT_PC,             offsetof(struct pt_regs, pc));
+	DEFINE(PT_ORIG_AO,        offsetof(struct pt_regs, orig_a0));
+	DEFINE(PT_SR,             offsetof(struct pt_regs, sr));
+
+	DEFINE(PT_A0,             offsetof(struct pt_regs, a0));
+	DEFINE(PT_A1,             offsetof(struct pt_regs, a1));
+	DEFINE(PT_A2,             offsetof(struct pt_regs, a2));
+	DEFINE(PT_A3,             offsetof(struct pt_regs, a3));
+	DEFINE(PT_REGS0,          offsetof(struct pt_regs, regs[0]));
+	DEFINE(PT_REGS1,          offsetof(struct pt_regs, regs[1]));
+	DEFINE(PT_REGS2,          offsetof(struct pt_regs, regs[2]));
+	DEFINE(PT_REGS3,          offsetof(struct pt_regs, regs[3]));
+	DEFINE(PT_REGS4,          offsetof(struct pt_regs, regs[4]));
+	DEFINE(PT_REGS5,          offsetof(struct pt_regs, regs[5]));
+	DEFINE(PT_REGS6,          offsetof(struct pt_regs, regs[6]));
+	DEFINE(PT_REGS7,          offsetof(struct pt_regs, regs[7]));
+	DEFINE(PT_REGS8,          offsetof(struct pt_regs, regs[8]));
+	DEFINE(PT_REGS9,          offsetof(struct pt_regs, regs[9]));
+	DEFINE(PT_R15,            offsetof(struct pt_regs, lr));
+#if defined(__CSKYABIV2__)
+	DEFINE(PT_R16,            offsetof(struct pt_regs, exregs[0]));
+	DEFINE(PT_R17,            offsetof(struct pt_regs, exregs[1]));
+	DEFINE(PT_R18,            offsetof(struct pt_regs, exregs[2]));
+	DEFINE(PT_R19,            offsetof(struct pt_regs, exregs[3]));
+	DEFINE(PT_R20,            offsetof(struct pt_regs, exregs[4]));
+	DEFINE(PT_R21,            offsetof(struct pt_regs, exregs[5]));
+	DEFINE(PT_R22,            offsetof(struct pt_regs, exregs[6]));
+	DEFINE(PT_R23,            offsetof(struct pt_regs, exregs[7]));
+	DEFINE(PT_R24,            offsetof(struct pt_regs, exregs[8]));
+	DEFINE(PT_R25,            offsetof(struct pt_regs, exregs[9]));
+	DEFINE(PT_R26,            offsetof(struct pt_regs, exregs[10]));
+	DEFINE(PT_R27,            offsetof(struct pt_regs, exregs[11]));
+	DEFINE(PT_R28,            offsetof(struct pt_regs, exregs[12]));
+	DEFINE(PT_R29,            offsetof(struct pt_regs, exregs[13]));
+	DEFINE(PT_R30,            offsetof(struct pt_regs, exregs[14]));
+	DEFINE(PT_R31,            offsetof(struct pt_regs, exregs[15]));
+	DEFINE(PT_RHI,            offsetof(struct pt_regs, rhi));
+	DEFINE(PT_RLO,            offsetof(struct pt_regs, rlo));
+#endif
+	DEFINE(PT_USP,            offsetof(struct pt_regs, usp));
+	DEFINE(PT_FRAME_SIZE,     sizeof(struct pt_regs));
+
+	/* offsets into the irq_cpustat_t struct */
+	DEFINE(CPUSTAT_SOFTIRQ_PENDING, offsetof(irq_cpustat_t,
+						__softirq_pending));
+
+	/* signal defines */
+	DEFINE(SIGSEGV, SIGSEGV);
+	DEFINE(SIGTRAP, SIGTRAP);
+
+	return 0;
+}
diff --git a/arch/csky/kernel/atomic.S b/arch/csky/kernel/atomic.S
new file mode 100644
index 000000000..3821ef9b7
--- /dev/null
+++ b/arch/csky/kernel/atomic.S
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include <abi/entry.h>
+
+.text
+
+/*
+ * int csky_cmpxchg(int oldval, int newval, int *ptr)
+ *
+ * If *ptr != oldval && return 1,
+ * else *ptr = newval return 0.
+ */
+ENTRY(csky_cmpxchg)
+	USPTOKSP
+	mfcr	a3, epc
+	addi	a3, TRAP0_SIZE
+
+	subi    sp, 16
+	stw     a3, (sp, 0)
+	mfcr    a3, epsr
+	stw     a3, (sp, 4)
+	mfcr	a3, usp
+	stw     a3, (sp, 8)
+
+	psrset	ee
+#ifdef CONFIG_CPU_HAS_LDSTEX
+1:
+	ldex	a3, (a2)
+	cmpne	a0, a3
+	bt16	2f
+	mov	a3, a1
+	stex	a3, (a2)
+	bez	a3, 1b
+2:
+	sync.is
+#else
+1:
+	ldw	a3, (a2)
+	cmpne	a0, a3
+	bt16	3f
+2:
+	stw	a1, (a2)
+3:
+#endif
+	mvc	a0
+	ldw	a3, (sp, 0)
+	mtcr	a3, epc
+	ldw     a3, (sp, 4)
+	mtcr	a3, epsr
+	ldw     a3, (sp, 8)
+	mtcr	a3, usp
+	addi	sp, 16
+	KSPTOUSP
+	rte
+END(csky_cmpxchg)
+
+#ifndef CONFIG_CPU_HAS_LDSTEX
+/*
+ * Called from tlbmodified exception
+ */
+ENTRY(csky_cmpxchg_fixup)
+	mfcr	a0, epc
+	lrw	a1, 2b
+	cmpne	a1, a0
+	bt	1f
+	subi	a1, (2b - 1b)
+	stw	a1, (sp, LSAVE_PC)
+1:
+	rts
+END(csky_cmpxchg_fixup)
+#endif
diff --git a/arch/csky/kernel/cpu-probe.c b/arch/csky/kernel/cpu-probe.c
new file mode 100644
index 000000000..5f15ca31d
--- /dev/null
+++ b/arch/csky/kernel/cpu-probe.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/of.h>
+#include <linux/init.h>
+#include <linux/seq_file.h>
+#include <linux/memblock.h>
+
+#include <abi/reg_ops.h>
+
+static void percpu_print(void *arg)
+{
+	struct seq_file *m = (struct seq_file *)arg;
+	unsigned int cur, next, i;
+
+	seq_printf(m, "processor       : %d\n", smp_processor_id());
+	seq_printf(m, "C-SKY CPU model : %s\n", CSKYCPU_DEF_NAME);
+
+	/* read processor id, max is 100 */
+	cur  = mfcr("cr13");
+	for (i = 0; i < 100; i++) {
+		seq_printf(m, "product info[%d] : 0x%08x\n", i, cur);
+
+		next = mfcr("cr13");
+
+		/* some CPU only has one id reg */
+		if (cur == next)
+			break;
+
+		cur = next;
+
+		/* cpid index is 31-28, reset */
+		if (!(next >> 28)) {
+			while ((mfcr("cr13") >> 28) != i);
+			break;
+		}
+	}
+
+	/* CPU feature regs, setup by bootloader or gdbinit */
+	seq_printf(m, "hint (CPU funcs): 0x%08x\n", mfcr_hint());
+	seq_printf(m, "ccr  (L1C & MMU): 0x%08x\n", mfcr("cr18"));
+	seq_printf(m, "ccr2 (L2C)      : 0x%08x\n", mfcr_ccr2());
+	seq_printf(m, "\n");
+}
+
+static int c_show(struct seq_file *m, void *v)
+{
+	int cpu;
+
+	for_each_online_cpu(cpu)
+		smp_call_function_single(cpu, percpu_print, m, true);
+
+#ifdef CSKY_ARCH_VERSION
+	seq_printf(m, "arch-version : %s\n", CSKY_ARCH_VERSION);
+	seq_printf(m, "\n");
+#endif
+
+	return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+	return *pos < 1 ? (void *)1 : NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	++*pos;
+	return NULL;
+}
+
+static void c_stop(struct seq_file *m, void *v) {}
+
+const struct seq_operations cpuinfo_op = {
+	.start	= c_start,
+	.next	= c_next,
+	.stop	= c_stop,
+	.show	= c_show,
+};
diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S
new file mode 100644
index 000000000..5a5cabd07
--- /dev/null
+++ b/arch/csky/kernel/entry.S
@@ -0,0 +1,378 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include <abi/entry.h>
+#include <abi/pgtable-bits.h>
+#include <asm/errno.h>
+#include <asm/setup.h>
+#include <asm/unistd.h>
+#include <asm/asm-offsets.h>
+#include <linux/threads.h>
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/thread_info.h>
+
+#define PTE_INDX_MSK    0xffc
+#define PTE_INDX_SHIFT  10
+#define _PGDIR_SHIFT    22
+
+.macro	zero_fp
+#ifdef CONFIG_STACKTRACE
+	movi	r8, 0
+#endif
+.endm
+
+.macro	context_tracking
+#ifdef CONFIG_CONTEXT_TRACKING
+	mfcr	a0, epsr
+	btsti	a0, 31
+	bt	1f
+	jbsr	context_tracking_user_exit
+	ldw	a0, (sp, LSAVE_A0)
+	ldw	a1, (sp, LSAVE_A1)
+	ldw	a2, (sp, LSAVE_A2)
+	ldw	a3, (sp, LSAVE_A3)
+#if defined(__CSKYABIV1__)
+	ldw	r6, (sp, LSAVE_A4)
+	ldw	r7, (sp, LSAVE_A5)
+#endif
+1:
+#endif
+.endm
+
+.macro tlbop_begin name, val0, val1, val2
+ENTRY(csky_\name)
+	mtcr    a3, ss2
+	mtcr    r6, ss3
+	mtcr    a2, ss4
+
+	RD_PGDR	r6
+	RD_MEH	a3
+#ifdef CONFIG_CPU_HAS_TLBI
+	tlbi.vaas a3
+	sync.is
+
+	btsti	a3, 31
+	bf	1f
+	RD_PGDR_K r6
+1:
+#else
+	bgeni	a2, 31
+	WR_MCIR	a2
+	bgeni	a2, 25
+	WR_MCIR	a2
+#endif
+	bclri   r6, 0
+	lrw	a2, va_pa_offset
+	ld.w	a2, (a2, 0)
+	subu	r6, a2
+	bseti	r6, 31
+
+	mov     a2, a3
+	lsri    a2, _PGDIR_SHIFT
+	lsli    a2, 2
+	addu    r6, a2
+	ldw     r6, (r6)
+
+	lrw	a2, va_pa_offset
+	ld.w	a2, (a2, 0)
+	subu	r6, a2
+	bseti	r6, 31
+
+	lsri    a3, PTE_INDX_SHIFT
+	lrw     a2, PTE_INDX_MSK
+	and     a3, a2
+	addu    r6, a3
+	ldw     a3, (r6)
+
+	movi	a2, (_PAGE_PRESENT | \val0)
+	and     a3, a2
+	cmpne   a3, a2
+	bt	\name
+
+	/* First read/write the page, just update the flags */
+	ldw     a3, (r6)
+	bgeni   a2, PAGE_VALID_BIT
+	bseti   a2, PAGE_ACCESSED_BIT
+	bseti   a2, \val1
+	bseti   a2, \val2
+	or      a3, a2
+	stw     a3, (r6)
+
+	/* Some cpu tlb-hardrefill bypass the cache */
+#ifdef CONFIG_CPU_NEED_TLBSYNC
+	movi	a2, 0x22
+	bseti	a2, 6
+	mtcr	r6, cr22
+	mtcr	a2, cr17
+	sync
+#endif
+
+	mfcr    a3, ss2
+	mfcr    r6, ss3
+	mfcr    a2, ss4
+	rte
+\name:
+	mfcr    a3, ss2
+	mfcr    r6, ss3
+	mfcr    a2, ss4
+	SAVE_ALL 0
+.endm
+.macro tlbop_end is_write
+	zero_fp
+	context_tracking
+	RD_MEH	a2
+	psrset  ee, ie
+	mov     a0, sp
+	movi    a1, \is_write
+	jbsr    do_page_fault
+	jmpi    ret_from_exception
+.endm
+
+.text
+
+tlbop_begin tlbinvalidl, _PAGE_READ, PAGE_VALID_BIT, PAGE_ACCESSED_BIT
+tlbop_end 0
+
+tlbop_begin tlbinvalids, _PAGE_WRITE, PAGE_DIRTY_BIT, PAGE_MODIFIED_BIT
+tlbop_end 1
+
+tlbop_begin tlbmodified, _PAGE_WRITE, PAGE_DIRTY_BIT, PAGE_MODIFIED_BIT
+#ifndef CONFIG_CPU_HAS_LDSTEX
+jbsr csky_cmpxchg_fixup
+#endif
+tlbop_end 1
+
+ENTRY(csky_systemcall)
+	SAVE_ALL TRAP0_SIZE
+	zero_fp
+	context_tracking
+	psrset  ee, ie
+
+	lrw     r9, __NR_syscalls
+	cmphs   syscallid, r9		/* Check nr of syscall */
+	bt      1f
+
+	lrw     r9, sys_call_table
+	ixw     r9, syscallid
+	ldw     syscallid, (r9)
+	cmpnei  syscallid, 0
+	bf      ret_from_exception
+
+	mov     r9, sp
+	bmaski  r10, THREAD_SHIFT
+	andn    r9, r10
+	ldw     r10, (r9, TINFO_FLAGS)
+	lrw	r9, _TIF_SYSCALL_WORK
+	and	r10, r9
+	cmpnei	r10, 0
+	bt      csky_syscall_trace
+#if defined(__CSKYABIV2__)
+	subi    sp, 8
+	stw  	r5, (sp, 0x4)
+	stw  	r4, (sp, 0x0)
+	jsr     syscallid                      /* Do system call */
+	addi 	sp, 8
+#else
+	jsr     syscallid
+#endif
+	stw     a0, (sp, LSAVE_A0)      /* Save return value */
+1:
+#ifdef CONFIG_DEBUG_RSEQ
+	mov	a0, sp
+	jbsr	rseq_syscall
+#endif
+	jmpi    ret_from_exception
+
+csky_syscall_trace:
+	mov	a0, sp                  /* sp = pt_regs pointer */
+	jbsr	syscall_trace_enter
+	cmpnei	a0, 0
+	bt	1f
+	/* Prepare args before do system call */
+	ldw	a0, (sp, LSAVE_A0)
+	ldw	a1, (sp, LSAVE_A1)
+	ldw	a2, (sp, LSAVE_A2)
+	ldw	a3, (sp, LSAVE_A3)
+#if defined(__CSKYABIV2__)
+	subi	sp, 8
+	ldw	r9, (sp, LSAVE_A4)
+	stw	r9, (sp, 0x0)
+	ldw	r9, (sp, LSAVE_A5)
+	stw	r9, (sp, 0x4)
+	jsr	syscallid                     /* Do system call */
+	addi	sp, 8
+#else
+	ldw	r6, (sp, LSAVE_A4)
+	ldw	r7, (sp, LSAVE_A5)
+	jsr	syscallid                     /* Do system call */
+#endif
+	stw	a0, (sp, LSAVE_A0)	/* Save return value */
+
+1:
+#ifdef CONFIG_DEBUG_RSEQ
+	mov	a0, sp
+	jbsr	rseq_syscall
+#endif
+	mov     a0, sp                  /* right now, sp --> pt_regs */
+	jbsr    syscall_trace_exit
+	br	ret_from_exception
+
+ENTRY(ret_from_kernel_thread)
+	jbsr	schedule_tail
+	mov	a0, r10
+	jsr	r9
+	jbsr	ret_from_exception
+
+ENTRY(ret_from_fork)
+	jbsr	schedule_tail
+	mov	r9, sp
+	bmaski	r10, THREAD_SHIFT
+	andn	r9, r10
+	ldw	r10, (r9, TINFO_FLAGS)
+	lrw	r9, _TIF_SYSCALL_WORK
+	and	r10, r9
+	cmpnei	r10, 0
+	bf	ret_from_exception
+	mov	a0, sp			/* sp = pt_regs pointer */
+	jbsr	syscall_trace_exit
+
+ret_from_exception:
+	psrclr	ie
+	ld	r9, (sp, LSAVE_PSR)
+	btsti	r9, 31
+
+	bt	1f
+	/*
+	 * Load address of current->thread_info, Then get address of task_struct
+	 * Get task_needreshed in task_struct
+	 */
+	mov	r9, sp
+	bmaski	r10, THREAD_SHIFT
+	andn	r9, r10
+
+	ldw	r10, (r9, TINFO_FLAGS)
+	lrw	r9, _TIF_WORK_MASK
+	and	r10, r9
+	cmpnei	r10, 0
+	bt	exit_work
+#ifdef CONFIG_CONTEXT_TRACKING
+	jbsr	context_tracking_user_enter
+#endif
+1:
+#ifdef CONFIG_PREEMPTION
+	mov	r9, sp
+	bmaski	r10, THREAD_SHIFT
+	andn	r9, r10
+
+	ldw	r10, (r9, TINFO_PREEMPT)
+	cmpnei	r10, 0
+	bt	2f
+	jbsr	preempt_schedule_irq	/* irq en/disable is done inside */
+2:
+#endif
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+	ld	r10, (sp, LSAVE_PSR)
+	btsti	r10, 6
+	bf	2f
+	jbsr	trace_hardirqs_on
+2:
+#endif
+	RESTORE_ALL
+
+exit_work:
+	lrw	r9, ret_from_exception
+	mov	lr, r9
+
+	btsti	r10, TIF_NEED_RESCHED
+	bt	work_resched
+
+	psrset	ie
+	mov	a0, sp
+	mov	a1, r10
+	jmpi	do_notify_resume
+
+work_resched:
+	jmpi	schedule
+
+ENTRY(csky_trap)
+	SAVE_ALL 0
+	zero_fp
+	context_tracking
+	psrset	ee
+	mov	a0, sp                 /* Push Stack pointer arg */
+	jbsr	trap_c                 /* Call C-level trap handler */
+	jmpi	ret_from_exception
+
+/*
+ * Prototype from libc for abiv1:
+ * register unsigned int __result asm("a0");
+ * asm( "trap 3" :"=r"(__result)::);
+ */
+ENTRY(csky_get_tls)
+	USPTOKSP
+
+	/* increase epc for continue */
+	mfcr	a0, epc
+	addi	a0, TRAP0_SIZE
+	mtcr	a0, epc
+
+	/* get current task thread_info with kernel 8K stack */
+	bmaski	a0, THREAD_SHIFT
+	not	a0
+	subi	sp, 1
+	and	a0, sp
+	addi	sp, 1
+
+	/* get tls */
+	ldw	a0, (a0, TINFO_TP_VALUE)
+
+	KSPTOUSP
+	rte
+
+ENTRY(csky_irq)
+	SAVE_ALL 0
+	zero_fp
+	context_tracking
+	psrset	ee
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+	jbsr	trace_hardirqs_off
+#endif
+
+
+	mov	a0, sp
+	jbsr	csky_do_IRQ
+
+	jmpi	ret_from_exception
+
+/*
+ * a0 =  prev task_struct *
+ * a1 =  next task_struct *
+ * a0 =  return next
+ */
+ENTRY(__switch_to)
+	lrw	a3, TASK_THREAD
+	addu	a3, a0
+
+	SAVE_SWITCH_STACK
+
+	stw	sp, (a3, THREAD_KSP)
+
+	/* Set up next process to run */
+	lrw	a3, TASK_THREAD
+	addu	a3, a1
+
+	ldw	sp, (a3, THREAD_KSP)	/* Set next kernel sp */
+
+#if  defined(__CSKYABIV2__)
+	addi	a3, a1, TASK_THREAD_INFO
+	ldw	tls, (a3, TINFO_TP_VALUE)
+#endif
+
+	RESTORE_SWITCH_STACK
+
+	rts
+ENDPROC(__switch_to)
diff --git a/arch/csky/kernel/ftrace.c b/arch/csky/kernel/ftrace.c
new file mode 100644
index 000000000..b4a7ec151
--- /dev/null
+++ b/arch/csky/kernel/ftrace.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/ftrace.h>
+#include <linux/uaccess.h>
+#include <linux/stop_machine.h>
+#include <asm/cacheflush.h>
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+#define NOP		0x4000
+#define NOP32_HI	0xc400
+#define NOP32_LO	0x4820
+#define PUSH_LR		0x14d0
+#define MOVIH_LINK	0xea3a
+#define ORI_LINK	0xef5a
+#define JSR_LINK	0xe8fa
+#define BSR_LINK	0xe000
+
+/*
+ * Gcc-csky with -pg will insert stub in function prologue:
+ *	push	lr
+ *	jbsr	_mcount
+ *	nop32
+ *	nop32
+ *
+ * If the (callee - current_pc) is less then 64MB, we'll use bsr:
+ *	push	lr
+ *	bsr	_mcount
+ *	nop32
+ *	nop32
+ * else we'll use (movih + ori + jsr):
+ *	push	lr
+ *	movih	r26, ...
+ *	ori	r26, ...
+ *	jsr	r26
+ *
+ * (r26 is our reserved link-reg)
+ *
+ */
+static inline void make_jbsr(unsigned long callee, unsigned long pc,
+			     uint16_t *call, bool nolr)
+{
+	long offset;
+
+	call[0]	= nolr ? NOP : PUSH_LR;
+
+	offset = (long) callee - (long) pc;
+
+	if (unlikely(offset < -67108864 || offset > 67108864)) {
+		call[1] = MOVIH_LINK;
+		call[2] = callee >> 16;
+		call[3] = ORI_LINK;
+		call[4] = callee & 0xffff;
+		call[5] = JSR_LINK;
+		call[6] = 0;
+	} else {
+		offset = offset >> 1;
+
+		call[1] = BSR_LINK |
+			 ((uint16_t)((unsigned long) offset >> 16) & 0x3ff);
+		call[2] = (uint16_t)((unsigned long) offset & 0xffff);
+		call[3] = call[5] = NOP32_HI;
+		call[4] = call[6] = NOP32_LO;
+	}
+}
+
+static uint16_t nops[7] = {NOP, NOP32_HI, NOP32_LO, NOP32_HI, NOP32_LO,
+				NOP32_HI, NOP32_LO};
+static int ftrace_check_current_nop(unsigned long hook)
+{
+	uint16_t olds[7];
+	unsigned long hook_pos = hook - 2;
+
+	if (copy_from_kernel_nofault((void *)olds, (void *)hook_pos,
+			sizeof(nops)))
+		return -EFAULT;
+
+	if (memcmp((void *)nops, (void *)olds, sizeof(nops))) {
+		pr_err("%p: nop but get (%04x %04x %04x %04x %04x %04x %04x)\n",
+			(void *)hook_pos,
+			olds[0], olds[1], olds[2], olds[3], olds[4], olds[5],
+			olds[6]);
+
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ftrace_modify_code(unsigned long hook, unsigned long target,
+			      bool enable, bool nolr)
+{
+	uint16_t call[7];
+
+	unsigned long hook_pos = hook - 2;
+	int ret = 0;
+
+	make_jbsr(target, hook, call, nolr);
+
+	ret = copy_to_kernel_nofault((void *)hook_pos, enable ? call : nops,
+				 sizeof(nops));
+	if (ret)
+		return -EPERM;
+
+	flush_icache_range(hook_pos, hook_pos + MCOUNT_INSN_SIZE);
+
+	return 0;
+}
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+	int ret = ftrace_check_current_nop(rec->ip);
+
+	if (ret)
+		return ret;
+
+	return ftrace_modify_code(rec->ip, addr, true, false);
+}
+
+int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
+		    unsigned long addr)
+{
+	return ftrace_modify_code(rec->ip, addr, false, false);
+}
+
+int ftrace_update_ftrace_func(ftrace_func_t func)
+{
+	int ret = ftrace_modify_code((unsigned long)&ftrace_call,
+				(unsigned long)func, true, true);
+	if (!ret)
+		ret = ftrace_modify_code((unsigned long)&ftrace_regs_call,
+				(unsigned long)func, true, true);
+	return ret;
+}
+
+int __init ftrace_dyn_arch_init(void)
+{
+	return 0;
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
+		       unsigned long addr)
+{
+	return ftrace_modify_code(rec->ip, addr, true, true);
+}
+#endif
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+			   unsigned long frame_pointer)
+{
+	unsigned long return_hooker = (unsigned long)&return_to_handler;
+	unsigned long old;
+
+	if (unlikely(atomic_read(&current->tracing_graph_pause)))
+		return;
+
+	old = *parent;
+
+	if (!function_graph_enter(old, self_addr,
+			*(unsigned long *)frame_pointer, parent)) {
+		/*
+		 * For csky-gcc function has sub-call:
+		 * subi	sp,	sp, 8
+		 * stw	r8,	(sp, 0)
+		 * mov	r8,	sp
+		 * st.w r15,	(sp, 0x4)
+		 * push	r15
+		 * jl	_mcount
+		 * We only need set *parent for resume
+		 *
+		 * For csky-gcc function has no sub-call:
+		 * subi	sp,	sp, 4
+		 * stw	r8,	(sp, 0)
+		 * mov	r8,	sp
+		 * push	r15
+		 * jl	_mcount
+		 * We need set *parent and *(frame_pointer + 4) for resume,
+		 * because lr is resumed twice.
+		 */
+		*parent = return_hooker;
+		frame_pointer += 4;
+		if (*(unsigned long *)frame_pointer == old)
+			*(unsigned long *)frame_pointer = return_hooker;
+	}
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+int ftrace_enable_ftrace_graph_caller(void)
+{
+	return ftrace_modify_code((unsigned long)&ftrace_graph_call,
+			(unsigned long)&ftrace_graph_caller, true, true);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+	return ftrace_modify_code((unsigned long)&ftrace_graph_call,
+			(unsigned long)&ftrace_graph_caller, false, true);
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+#ifndef CONFIG_CPU_HAS_ICACHE_INS
+struct ftrace_modify_param {
+	int command;
+	atomic_t cpu_count;
+};
+
+static int __ftrace_modify_code(void *data)
+{
+	struct ftrace_modify_param *param = data;
+
+	if (atomic_inc_return(&param->cpu_count) == 1) {
+		ftrace_modify_all_code(param->command);
+		atomic_inc(&param->cpu_count);
+	} else {
+		while (atomic_read(&param->cpu_count) <= num_online_cpus())
+			cpu_relax();
+		local_icache_inv_all(NULL);
+	}
+
+	return 0;
+}
+
+void arch_ftrace_update_code(int command)
+{
+	struct ftrace_modify_param param = { command, ATOMIC_INIT(0) };
+
+	stop_machine(__ftrace_modify_code, &param, cpu_online_mask);
+}
+#endif
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+/* _mcount is defined in abi's mcount.S */
+EXPORT_SYMBOL(_mcount);
diff --git a/arch/csky/kernel/head.S b/arch/csky/kernel/head.S
new file mode 100644
index 000000000..17ed9d250
--- /dev/null
+++ b/arch/csky/kernel/head.S
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/page.h>
+#include <abi/entry.h>
+
+__HEAD
+ENTRY(_start)
+	SETUP_MMU
+
+	/* set stack point */
+	lrw     r6, init_thread_union + THREAD_SIZE
+	mov	sp, r6
+
+	jmpi	csky_start
+END(_start)
+
+#ifdef CONFIG_SMP
+.align 10
+ENTRY(_start_smp_secondary)
+	SETUP_MMU
+
+	/* copy msa1 from CPU0 */
+	lrw     r6, secondary_msa1
+	ld.w	r6, (r6, 0)
+	mtcr	r6, cr<31, 15>
+
+	/* set stack point */
+	lrw     r6, secondary_stack
+	ld.w	r6, (r6, 0)
+	mov	sp, r6
+
+	jmpi	csky_start_secondary
+END(_start_smp_secondary)
+#endif
diff --git a/arch/csky/kernel/irq.c b/arch/csky/kernel/irq.c
new file mode 100644
index 000000000..03a1930f1
--- /dev/null
+++ b/arch/csky/kernel/irq.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <asm/traps.h>
+#include <asm/smp.h>
+
+void __init init_IRQ(void)
+{
+	irqchip_init();
+#ifdef CONFIG_SMP
+	setup_smp_ipi();
+#endif
+}
+
+asmlinkage void __irq_entry csky_do_IRQ(struct pt_regs *regs)
+{
+	handle_arch_irq(regs);
+}
diff --git a/arch/csky/kernel/module.c b/arch/csky/kernel/module.c
new file mode 100644
index 000000000..6cd82d69c
--- /dev/null
+++ b/arch/csky/kernel/module.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+
+#ifdef CONFIG_CPU_CK810
+#define IS_BSR32(hi16, lo16)		(((hi16) & 0xFC00) == 0xE000)
+#define IS_JSRI32(hi16, lo16)		((hi16) == 0xEAE0)
+
+#define CHANGE_JSRI_TO_LRW(addr) do {					\
+	*(uint16_t *)(addr) = (*(uint16_t *)(addr) & 0xFF9F) | 0x001a;	\
+	*((uint16_t *)(addr) + 1) = *((uint16_t *)(addr) + 1) & 0xFFFF;	\
+} while (0)
+
+#define SET_JSR32_R26(addr) do {		\
+	*(uint16_t *)(addr) = 0xE8Fa;		\
+	*((uint16_t *)(addr) + 1) = 0x0000;	\
+} while (0)
+
+static void jsri_2_lrw_jsr(uint32_t *location)
+{
+	uint16_t *location_tmp = (uint16_t *)location;
+
+	if (IS_BSR32(*location_tmp, *(location_tmp + 1)))
+		return;
+
+	if (IS_JSRI32(*location_tmp, *(location_tmp + 1))) {
+		/* jsri 0x...  --> lrw r26, 0x... */
+		CHANGE_JSRI_TO_LRW(location);
+		/* lsli r0, r0 --> jsr r26 */
+		SET_JSR32_R26(location + 1);
+	}
+}
+#else
+static void inline jsri_2_lrw_jsr(uint32_t *location)
+{
+	return;
+}
+#endif
+
+int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
+		unsigned int symindex, unsigned int relsec, struct module *me)
+{
+	unsigned int i;
+	Elf32_Rela	*rel = (void *) sechdrs[relsec].sh_addr;
+	Elf32_Sym	*sym;
+	uint32_t	*location;
+	short		*temp;
+
+	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+		/* This is where to make the change */
+		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+							+ rel[i].r_offset;
+		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+						+ ELF32_R_SYM(rel[i].r_info);
+
+		switch (ELF32_R_TYPE(rel[i].r_info)) {
+		case R_CSKY_32:
+			/* We add the value into the location given */
+			*location = rel[i].r_addend + sym->st_value;
+			break;
+		case R_CSKY_PC32:
+			/* Add the value, subtract its postition */
+			*location = rel[i].r_addend + sym->st_value
+							- (uint32_t)location;
+			break;
+		case R_CSKY_PCRELJSR_IMM11BY2:
+			break;
+		case R_CSKY_PCRELJSR_IMM26BY2:
+			jsri_2_lrw_jsr(location);
+			break;
+		case R_CSKY_ADDR_HI16:
+			temp = ((short  *)location) + 1;
+			*temp = (short)
+				((rel[i].r_addend + sym->st_value) >> 16);
+			break;
+		case R_CSKY_ADDR_LO16:
+			temp = ((short  *)location) + 1;
+			*temp = (short)
+				((rel[i].r_addend + sym->st_value) & 0xffff);
+			break;
+		default:
+			pr_err("module %s: Unknown relocation: %u\n",
+				me->name, ELF32_R_TYPE(rel[i].r_info));
+			return -ENOEXEC;
+		}
+	}
+	return 0;
+}
diff --git a/arch/csky/kernel/perf_callchain.c b/arch/csky/kernel/perf_callchain.c
new file mode 100644
index 000000000..75e1f9df5
--- /dev/null
+++ b/arch/csky/kernel/perf_callchain.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/perf_event.h>
+#include <linux/uaccess.h>
+
+/* Kernel callchain */
+struct stackframe {
+	unsigned long fp;
+	unsigned long lr;
+};
+
+static int unwind_frame_kernel(struct stackframe *frame)
+{
+	unsigned long low = (unsigned long)task_stack_page(current);
+	unsigned long high = low + THREAD_SIZE;
+
+	if (unlikely(frame->fp < low || frame->fp > high))
+		return -EPERM;
+
+	if (kstack_end((void *)frame->fp) || frame->fp & 0x3)
+		return -EPERM;
+
+	*frame = *(struct stackframe *)frame->fp;
+
+	if (__kernel_text_address(frame->lr)) {
+		int graph = 0;
+
+		frame->lr = ftrace_graph_ret_addr(NULL, &graph, frame->lr,
+				NULL);
+	}
+	return 0;
+}
+
+static void notrace walk_stackframe(struct stackframe *fr,
+			struct perf_callchain_entry_ctx *entry)
+{
+	do {
+		perf_callchain_store(entry, fr->lr);
+	} while (unwind_frame_kernel(fr) >= 0);
+}
+
+/*
+ * Get the return address for a single stackframe and return a pointer to the
+ * next frame tail.
+ */
+static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry,
+			unsigned long fp, unsigned long reg_lr)
+{
+	struct stackframe buftail;
+	unsigned long lr = 0;
+	unsigned long __user *user_frame_tail = (unsigned long __user *)fp;
+
+	/* Check accessibility of one struct frame_tail beyond */
+	if (!access_ok(user_frame_tail, sizeof(buftail)))
+		return 0;
+	if (__copy_from_user_inatomic(&buftail, user_frame_tail,
+				      sizeof(buftail)))
+		return 0;
+
+	if (reg_lr != 0)
+		lr = reg_lr;
+	else
+		lr = buftail.lr;
+
+	fp = buftail.fp;
+	perf_callchain_store(entry, lr);
+
+	return fp;
+}
+
+/*
+ * This will be called when the target is in user mode
+ * This function will only be called when we use
+ * "PERF_SAMPLE_CALLCHAIN" in
+ * kernel/events/core.c:perf_prepare_sample()
+ *
+ * How to trigger perf_callchain_[user/kernel] :
+ * $ perf record -e cpu-clock --call-graph fp ./program
+ * $ perf report --call-graph
+ *
+ * On C-SKY platform, the program being sampled and the C library
+ * need to be compiled with * -mbacktrace, otherwise the user
+ * stack will not contain function frame.
+ */
+void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
+			 struct pt_regs *regs)
+{
+	struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
+	unsigned long fp = 0;
+
+	/* C-SKY does not support virtualization. */
+	if (guest_cbs && guest_cbs->is_in_guest())
+		return;
+
+	fp = regs->regs[4];
+	perf_callchain_store(entry, regs->pc);
+
+	/*
+	 * While backtrace from leaf function, lr is normally
+	 * not saved inside frame on C-SKY, so get lr from pt_regs
+	 * at the sample point. However, lr value can be incorrect if
+	 * lr is used as temp register
+	 */
+	fp = user_backtrace(entry, fp, regs->lr);
+
+	while (fp && !(fp & 0x3) && entry->nr < entry->max_stack)
+		fp = user_backtrace(entry, fp, 0);
+}
+
+void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
+			   struct pt_regs *regs)
+{
+	struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs();
+	struct stackframe fr;
+
+	/* C-SKY does not support virtualization. */
+	if (guest_cbs && guest_cbs->is_in_guest()) {
+		pr_warn("C-SKY does not support perf in guest mode!");
+		return;
+	}
+
+	fr.fp = regs->regs[4];
+	fr.lr = regs->lr;
+	walk_stackframe(&fr, entry);
+}
diff --git a/arch/csky/kernel/perf_event.c b/arch/csky/kernel/perf_event.c
new file mode 100644
index 000000000..1a29f1157
--- /dev/null
+++ b/arch/csky/kernel/perf_event.c
@@ -0,0 +1,1371 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+
+#define CSKY_PMU_MAX_EVENTS 32
+#define DEFAULT_COUNT_WIDTH 48
+
+#define HPCR		"<0, 0x0>"      /* PMU Control reg */
+#define HPSPR		"<0, 0x1>"      /* Start PC reg */
+#define HPEPR		"<0, 0x2>"      /* End PC reg */
+#define HPSIR		"<0, 0x3>"      /* Soft Counter reg */
+#define HPCNTENR	"<0, 0x4>"      /* Count Enable reg */
+#define HPINTENR	"<0, 0x5>"      /* Interrupt Enable reg */
+#define HPOFSR		"<0, 0x6>"      /* Interrupt Status reg */
+
+/* The events for a given PMU register set. */
+struct pmu_hw_events {
+	/*
+	 * The events that are active on the PMU for the given index.
+	 */
+	struct perf_event *events[CSKY_PMU_MAX_EVENTS];
+
+	/*
+	 * A 1 bit for an index indicates that the counter is being used for
+	 * an event. A 0 means that the counter can be used.
+	 */
+	unsigned long used_mask[BITS_TO_LONGS(CSKY_PMU_MAX_EVENTS)];
+};
+
+static uint64_t (*hw_raw_read_mapping[CSKY_PMU_MAX_EVENTS])(void);
+static void (*hw_raw_write_mapping[CSKY_PMU_MAX_EVENTS])(uint64_t val);
+
+static struct csky_pmu_t {
+	struct pmu			pmu;
+	struct pmu_hw_events __percpu	*hw_events;
+	struct platform_device		*plat_device;
+	uint32_t			count_width;
+	uint32_t			hpcr;
+	u64				max_period;
+} csky_pmu;
+static int csky_pmu_irq;
+
+#define to_csky_pmu(p)  (container_of(p, struct csky_pmu, pmu))
+
+#define cprgr(reg)				\
+({						\
+	unsigned int tmp;			\
+	asm volatile("cprgr %0, "reg"\n"	\
+		     : "=r"(tmp)		\
+		     :				\
+		     : "memory");		\
+	tmp;					\
+})
+
+#define cpwgr(reg, val)		\
+({				\
+	asm volatile(		\
+	"cpwgr %0, "reg"\n"	\
+	:			\
+	: "r"(val)		\
+	: "memory");		\
+})
+
+#define cprcr(reg)				\
+({						\
+	unsigned int tmp;			\
+	asm volatile("cprcr %0, "reg"\n"	\
+		     : "=r"(tmp)		\
+		     :				\
+		     : "memory");		\
+	tmp;					\
+})
+
+#define cpwcr(reg, val)		\
+({				\
+	asm volatile(		\
+	"cpwcr %0, "reg"\n"	\
+	:			\
+	: "r"(val)		\
+	: "memory");		\
+})
+
+/* cycle counter */
+static uint64_t csky_pmu_read_cc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x3>");
+		lo  = cprgr("<0, 0x2>");
+		hi  = cprgr("<0, 0x3>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_cc(uint64_t val)
+{
+	cpwgr("<0, 0x2>", (uint32_t)  val);
+	cpwgr("<0, 0x3>", (uint32_t) (val >> 32));
+}
+
+/* instruction counter */
+static uint64_t csky_pmu_read_ic(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x5>");
+		lo  = cprgr("<0, 0x4>");
+		hi  = cprgr("<0, 0x5>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_ic(uint64_t val)
+{
+	cpwgr("<0, 0x4>", (uint32_t)  val);
+	cpwgr("<0, 0x5>", (uint32_t) (val >> 32));
+}
+
+/* l1 icache access counter */
+static uint64_t csky_pmu_read_icac(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x7>");
+		lo  = cprgr("<0, 0x6>");
+		hi  = cprgr("<0, 0x7>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_icac(uint64_t val)
+{
+	cpwgr("<0, 0x6>", (uint32_t)  val);
+	cpwgr("<0, 0x7>", (uint32_t) (val >> 32));
+}
+
+/* l1 icache miss counter */
+static uint64_t csky_pmu_read_icmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x9>");
+		lo  = cprgr("<0, 0x8>");
+		hi  = cprgr("<0, 0x9>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_icmc(uint64_t val)
+{
+	cpwgr("<0, 0x8>", (uint32_t)  val);
+	cpwgr("<0, 0x9>", (uint32_t) (val >> 32));
+}
+
+/* l1 dcache access counter */
+static uint64_t csky_pmu_read_dcac(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0xb>");
+		lo  = cprgr("<0, 0xa>");
+		hi  = cprgr("<0, 0xb>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_dcac(uint64_t val)
+{
+	cpwgr("<0, 0xa>", (uint32_t)  val);
+	cpwgr("<0, 0xb>", (uint32_t) (val >> 32));
+}
+
+/* l1 dcache miss counter */
+static uint64_t csky_pmu_read_dcmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0xd>");
+		lo  = cprgr("<0, 0xc>");
+		hi  = cprgr("<0, 0xd>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_dcmc(uint64_t val)
+{
+	cpwgr("<0, 0xc>", (uint32_t)  val);
+	cpwgr("<0, 0xd>", (uint32_t) (val >> 32));
+}
+
+/* l2 cache access counter */
+static uint64_t csky_pmu_read_l2ac(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0xf>");
+		lo  = cprgr("<0, 0xe>");
+		hi  = cprgr("<0, 0xf>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_l2ac(uint64_t val)
+{
+	cpwgr("<0, 0xe>", (uint32_t)  val);
+	cpwgr("<0, 0xf>", (uint32_t) (val >> 32));
+}
+
+/* l2 cache miss counter */
+static uint64_t csky_pmu_read_l2mc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x11>");
+		lo  = cprgr("<0, 0x10>");
+		hi  = cprgr("<0, 0x11>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_l2mc(uint64_t val)
+{
+	cpwgr("<0, 0x10>", (uint32_t)  val);
+	cpwgr("<0, 0x11>", (uint32_t) (val >> 32));
+}
+
+/* I-UTLB miss counter */
+static uint64_t csky_pmu_read_iutlbmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x15>");
+		lo  = cprgr("<0, 0x14>");
+		hi  = cprgr("<0, 0x15>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_iutlbmc(uint64_t val)
+{
+	cpwgr("<0, 0x14>", (uint32_t)  val);
+	cpwgr("<0, 0x15>", (uint32_t) (val >> 32));
+}
+
+/* D-UTLB miss counter */
+static uint64_t csky_pmu_read_dutlbmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x17>");
+		lo  = cprgr("<0, 0x16>");
+		hi  = cprgr("<0, 0x17>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_dutlbmc(uint64_t val)
+{
+	cpwgr("<0, 0x16>", (uint32_t)  val);
+	cpwgr("<0, 0x17>", (uint32_t) (val >> 32));
+}
+
+/* JTLB miss counter */
+static uint64_t csky_pmu_read_jtlbmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x19>");
+		lo  = cprgr("<0, 0x18>");
+		hi  = cprgr("<0, 0x19>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_jtlbmc(uint64_t val)
+{
+	cpwgr("<0, 0x18>", (uint32_t)  val);
+	cpwgr("<0, 0x19>", (uint32_t) (val >> 32));
+}
+
+/* software counter */
+static uint64_t csky_pmu_read_softc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x1b>");
+		lo  = cprgr("<0, 0x1a>");
+		hi  = cprgr("<0, 0x1b>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_softc(uint64_t val)
+{
+	cpwgr("<0, 0x1a>", (uint32_t)  val);
+	cpwgr("<0, 0x1b>", (uint32_t) (val >> 32));
+}
+
+/* conditional branch mispredict counter */
+static uint64_t csky_pmu_read_cbmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x1d>");
+		lo  = cprgr("<0, 0x1c>");
+		hi  = cprgr("<0, 0x1d>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_cbmc(uint64_t val)
+{
+	cpwgr("<0, 0x1c>", (uint32_t)  val);
+	cpwgr("<0, 0x1d>", (uint32_t) (val >> 32));
+}
+
+/* conditional branch instruction counter */
+static uint64_t csky_pmu_read_cbic(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x1f>");
+		lo  = cprgr("<0, 0x1e>");
+		hi  = cprgr("<0, 0x1f>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_cbic(uint64_t val)
+{
+	cpwgr("<0, 0x1e>", (uint32_t)  val);
+	cpwgr("<0, 0x1f>", (uint32_t) (val >> 32));
+}
+
+/* indirect branch mispredict counter */
+static uint64_t csky_pmu_read_ibmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x21>");
+		lo  = cprgr("<0, 0x20>");
+		hi  = cprgr("<0, 0x21>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_ibmc(uint64_t val)
+{
+	cpwgr("<0, 0x20>", (uint32_t)  val);
+	cpwgr("<0, 0x21>", (uint32_t) (val >> 32));
+}
+
+/* indirect branch instruction counter */
+static uint64_t csky_pmu_read_ibic(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x23>");
+		lo  = cprgr("<0, 0x22>");
+		hi  = cprgr("<0, 0x23>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_ibic(uint64_t val)
+{
+	cpwgr("<0, 0x22>", (uint32_t)  val);
+	cpwgr("<0, 0x23>", (uint32_t) (val >> 32));
+}
+
+/* LSU spec fail counter */
+static uint64_t csky_pmu_read_lsfc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x25>");
+		lo  = cprgr("<0, 0x24>");
+		hi  = cprgr("<0, 0x25>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_lsfc(uint64_t val)
+{
+	cpwgr("<0, 0x24>", (uint32_t)  val);
+	cpwgr("<0, 0x25>", (uint32_t) (val >> 32));
+}
+
+/* store instruction counter */
+static uint64_t csky_pmu_read_sic(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x27>");
+		lo  = cprgr("<0, 0x26>");
+		hi  = cprgr("<0, 0x27>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_sic(uint64_t val)
+{
+	cpwgr("<0, 0x26>", (uint32_t)  val);
+	cpwgr("<0, 0x27>", (uint32_t) (val >> 32));
+}
+
+/* dcache read access counter */
+static uint64_t csky_pmu_read_dcrac(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x29>");
+		lo  = cprgr("<0, 0x28>");
+		hi  = cprgr("<0, 0x29>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_dcrac(uint64_t val)
+{
+	cpwgr("<0, 0x28>", (uint32_t)  val);
+	cpwgr("<0, 0x29>", (uint32_t) (val >> 32));
+}
+
+/* dcache read miss counter */
+static uint64_t csky_pmu_read_dcrmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x2b>");
+		lo  = cprgr("<0, 0x2a>");
+		hi  = cprgr("<0, 0x2b>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_dcrmc(uint64_t val)
+{
+	cpwgr("<0, 0x2a>", (uint32_t)  val);
+	cpwgr("<0, 0x2b>", (uint32_t) (val >> 32));
+}
+
+/* dcache write access counter */
+static uint64_t csky_pmu_read_dcwac(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x2d>");
+		lo  = cprgr("<0, 0x2c>");
+		hi  = cprgr("<0, 0x2d>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_dcwac(uint64_t val)
+{
+	cpwgr("<0, 0x2c>", (uint32_t)  val);
+	cpwgr("<0, 0x2d>", (uint32_t) (val >> 32));
+}
+
+/* dcache write miss counter */
+static uint64_t csky_pmu_read_dcwmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x2f>");
+		lo  = cprgr("<0, 0x2e>");
+		hi  = cprgr("<0, 0x2f>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_dcwmc(uint64_t val)
+{
+	cpwgr("<0, 0x2e>", (uint32_t)  val);
+	cpwgr("<0, 0x2f>", (uint32_t) (val >> 32));
+}
+
+/* l2cache read access counter */
+static uint64_t csky_pmu_read_l2rac(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x31>");
+		lo  = cprgr("<0, 0x30>");
+		hi  = cprgr("<0, 0x31>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_l2rac(uint64_t val)
+{
+	cpwgr("<0, 0x30>", (uint32_t)  val);
+	cpwgr("<0, 0x31>", (uint32_t) (val >> 32));
+}
+
+/* l2cache read miss counter */
+static uint64_t csky_pmu_read_l2rmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x33>");
+		lo  = cprgr("<0, 0x32>");
+		hi  = cprgr("<0, 0x33>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_l2rmc(uint64_t val)
+{
+	cpwgr("<0, 0x32>", (uint32_t)  val);
+	cpwgr("<0, 0x33>", (uint32_t) (val >> 32));
+}
+
+/* l2cache write access counter */
+static uint64_t csky_pmu_read_l2wac(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x35>");
+		lo  = cprgr("<0, 0x34>");
+		hi  = cprgr("<0, 0x35>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_l2wac(uint64_t val)
+{
+	cpwgr("<0, 0x34>", (uint32_t)  val);
+	cpwgr("<0, 0x35>", (uint32_t) (val >> 32));
+}
+
+/* l2cache write miss counter */
+static uint64_t csky_pmu_read_l2wmc(void)
+{
+	uint32_t lo, hi, tmp;
+	uint64_t result;
+
+	do {
+		tmp = cprgr("<0, 0x37>");
+		lo  = cprgr("<0, 0x36>");
+		hi  = cprgr("<0, 0x37>");
+	} while (hi != tmp);
+
+	result = (uint64_t) (hi) << 32;
+	result |= lo;
+
+	return result;
+}
+
+static void csky_pmu_write_l2wmc(uint64_t val)
+{
+	cpwgr("<0, 0x36>", (uint32_t)  val);
+	cpwgr("<0, 0x37>", (uint32_t) (val >> 32));
+}
+
+#define HW_OP_UNSUPPORTED	0xffff
+static const int csky_pmu_hw_map[PERF_COUNT_HW_MAX] = {
+	[PERF_COUNT_HW_CPU_CYCLES]		= 0x1,
+	[PERF_COUNT_HW_INSTRUCTIONS]		= 0x2,
+	[PERF_COUNT_HW_CACHE_REFERENCES]	= HW_OP_UNSUPPORTED,
+	[PERF_COUNT_HW_CACHE_MISSES]		= HW_OP_UNSUPPORTED,
+	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= 0xf,
+	[PERF_COUNT_HW_BRANCH_MISSES]		= 0xe,
+	[PERF_COUNT_HW_BUS_CYCLES]		= HW_OP_UNSUPPORTED,
+	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= HW_OP_UNSUPPORTED,
+	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= HW_OP_UNSUPPORTED,
+	[PERF_COUNT_HW_REF_CPU_CYCLES]		= HW_OP_UNSUPPORTED,
+};
+
+#define C(_x)			PERF_COUNT_HW_CACHE_##_x
+#define CACHE_OP_UNSUPPORTED	0xffff
+static const int csky_pmu_cache_map[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = {
+	[C(L1D)] = {
+#ifdef CONFIG_CPU_CK810
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)]	= 0x5,
+			[C(RESULT_MISS)]	= 0x6,
+		},
+#else
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= 0x14,
+			[C(RESULT_MISS)]	= 0x15,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= 0x16,
+			[C(RESULT_MISS)]	= 0x17,
+		},
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+#endif
+	},
+	[C(L1I)] = {
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= 0x3,
+			[C(RESULT_MISS)]	= 0x4,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+	},
+	[C(LL)] = {
+#ifdef CONFIG_CPU_CK810
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)]	= 0x7,
+			[C(RESULT_MISS)]	= 0x8,
+		},
+#else
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= 0x18,
+			[C(RESULT_MISS)]	= 0x19,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= 0x1a,
+			[C(RESULT_MISS)]	= 0x1b,
+		},
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+#endif
+	},
+	[C(DTLB)] = {
+#ifdef CONFIG_CPU_CK810
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+#else
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= 0x14,
+			[C(RESULT_MISS)]	= 0xb,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= 0x16,
+			[C(RESULT_MISS)]	= 0xb,
+		},
+#endif
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+	},
+	[C(ITLB)] = {
+#ifdef CONFIG_CPU_CK810
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+#else
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= 0x3,
+			[C(RESULT_MISS)]	= 0xa,
+		},
+#endif
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+	},
+	[C(BPU)] = {
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+	},
+	[C(NODE)] = {
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)]	= CACHE_OP_UNSUPPORTED,
+			[C(RESULT_MISS)]	= CACHE_OP_UNSUPPORTED,
+		},
+	},
+};
+
+int  csky_pmu_event_set_period(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	s64 left = local64_read(&hwc->period_left);
+	s64 period = hwc->sample_period;
+	int ret = 0;
+
+	if (unlikely(left <= -period)) {
+		left = period;
+		local64_set(&hwc->period_left, left);
+		hwc->last_period = period;
+		ret = 1;
+	}
+
+	if (unlikely(left <= 0)) {
+		left += period;
+		local64_set(&hwc->period_left, left);
+		hwc->last_period = period;
+		ret = 1;
+	}
+
+	if (left > (s64)csky_pmu.max_period)
+		left = csky_pmu.max_period;
+
+	/*
+	 * The hw event starts counting from this event offset,
+	 * mark it to be able to extract future "deltas":
+	 */
+	local64_set(&hwc->prev_count, (u64)(-left));
+
+	if (hw_raw_write_mapping[hwc->idx] != NULL)
+		hw_raw_write_mapping[hwc->idx]((u64)(-left) &
+						csky_pmu.max_period);
+
+	cpwcr(HPOFSR, ~BIT(hwc->idx) & cprcr(HPOFSR));
+
+	perf_event_update_userpage(event);
+
+	return ret;
+}
+
+static void csky_perf_event_update(struct perf_event *event,
+				   struct hw_perf_event *hwc)
+{
+	uint64_t prev_raw_count = local64_read(&hwc->prev_count);
+	/*
+	 * Sign extend count value to 64bit, otherwise delta calculation
+	 * would be incorrect when overflow occurs.
+	 */
+	uint64_t new_raw_count = sign_extend64(
+		hw_raw_read_mapping[hwc->idx](), csky_pmu.count_width - 1);
+	int64_t delta = new_raw_count - prev_raw_count;
+
+	/*
+	 * We aren't afraid of hwc->prev_count changing beneath our feet
+	 * because there's no way for us to re-enter this function anytime.
+	 */
+	local64_set(&hwc->prev_count, new_raw_count);
+	local64_add(delta, &event->count);
+	local64_sub(delta, &hwc->period_left);
+}
+
+static void csky_pmu_reset(void *info)
+{
+	cpwcr(HPCR, BIT(31) | BIT(30) | BIT(1));
+}
+
+static void csky_pmu_read(struct perf_event *event)
+{
+	csky_perf_event_update(event, &event->hw);
+}
+
+static int csky_pmu_cache_event(u64 config)
+{
+	unsigned int cache_type, cache_op, cache_result;
+
+	cache_type	= (config >>  0) & 0xff;
+	cache_op	= (config >>  8) & 0xff;
+	cache_result	= (config >> 16) & 0xff;
+
+	if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
+		return -EINVAL;
+	if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
+		return -EINVAL;
+	if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
+		return -EINVAL;
+
+	return csky_pmu_cache_map[cache_type][cache_op][cache_result];
+}
+
+static int csky_pmu_event_init(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	int ret;
+
+	switch (event->attr.type) {
+	case PERF_TYPE_HARDWARE:
+		if (event->attr.config >= PERF_COUNT_HW_MAX)
+			return -ENOENT;
+		ret = csky_pmu_hw_map[event->attr.config];
+		if (ret == HW_OP_UNSUPPORTED)
+			return -ENOENT;
+		hwc->idx = ret;
+		break;
+	case PERF_TYPE_HW_CACHE:
+		ret = csky_pmu_cache_event(event->attr.config);
+		if (ret == CACHE_OP_UNSUPPORTED)
+			return -ENOENT;
+		hwc->idx = ret;
+		break;
+	case PERF_TYPE_RAW:
+		if (hw_raw_read_mapping[event->attr.config] == NULL)
+			return -ENOENT;
+		hwc->idx = event->attr.config;
+		break;
+	default:
+		return -ENOENT;
+	}
+
+	if (event->attr.exclude_user)
+		csky_pmu.hpcr = BIT(2);
+	else if (event->attr.exclude_kernel)
+		csky_pmu.hpcr = BIT(3);
+	else
+		csky_pmu.hpcr = BIT(2) | BIT(3);
+
+	csky_pmu.hpcr |= BIT(1) | BIT(0);
+
+	return 0;
+}
+
+/* starts all counters */
+static void csky_pmu_enable(struct pmu *pmu)
+{
+	cpwcr(HPCR, csky_pmu.hpcr);
+}
+
+/* stops all counters */
+static void csky_pmu_disable(struct pmu *pmu)
+{
+	cpwcr(HPCR, BIT(1));
+}
+
+static void csky_pmu_start(struct perf_event *event, int flags)
+{
+	unsigned long flg;
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = hwc->idx;
+
+	if (WARN_ON_ONCE(idx == -1))
+		return;
+
+	if (flags & PERF_EF_RELOAD)
+		WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+
+	hwc->state = 0;
+
+	csky_pmu_event_set_period(event);
+
+	local_irq_save(flg);
+
+	cpwcr(HPINTENR, BIT(idx) | cprcr(HPINTENR));
+	cpwcr(HPCNTENR, BIT(idx) | cprcr(HPCNTENR));
+
+	local_irq_restore(flg);
+}
+
+static void csky_pmu_stop_event(struct perf_event *event)
+{
+	unsigned long flg;
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = hwc->idx;
+
+	local_irq_save(flg);
+
+	cpwcr(HPINTENR, ~BIT(idx) & cprcr(HPINTENR));
+	cpwcr(HPCNTENR, ~BIT(idx) & cprcr(HPCNTENR));
+
+	local_irq_restore(flg);
+}
+
+static void csky_pmu_stop(struct perf_event *event, int flags)
+{
+	if (!(event->hw.state & PERF_HES_STOPPED)) {
+		csky_pmu_stop_event(event);
+		event->hw.state |= PERF_HES_STOPPED;
+	}
+
+	if ((flags & PERF_EF_UPDATE) &&
+	    !(event->hw.state & PERF_HES_UPTODATE)) {
+		csky_perf_event_update(event, &event->hw);
+		event->hw.state |= PERF_HES_UPTODATE;
+	}
+}
+
+static void csky_pmu_del(struct perf_event *event, int flags)
+{
+	struct pmu_hw_events *hw_events = this_cpu_ptr(csky_pmu.hw_events);
+	struct hw_perf_event *hwc = &event->hw;
+
+	csky_pmu_stop(event, PERF_EF_UPDATE);
+
+	hw_events->events[hwc->idx] = NULL;
+
+	perf_event_update_userpage(event);
+}
+
+/* allocate hardware counter and optionally start counting */
+static int csky_pmu_add(struct perf_event *event, int flags)
+{
+	struct pmu_hw_events *hw_events = this_cpu_ptr(csky_pmu.hw_events);
+	struct hw_perf_event *hwc = &event->hw;
+
+	hw_events->events[hwc->idx] = event;
+
+	hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+
+	if (flags & PERF_EF_START)
+		csky_pmu_start(event, PERF_EF_RELOAD);
+
+	perf_event_update_userpage(event);
+
+	return 0;
+}
+
+static irqreturn_t csky_pmu_handle_irq(int irq_num, void *dev)
+{
+	struct perf_sample_data data;
+	struct pmu_hw_events *cpuc = this_cpu_ptr(csky_pmu.hw_events);
+	struct pt_regs *regs;
+	int idx;
+
+	/*
+	 * Did an overflow occur?
+	 */
+	if (!cprcr(HPOFSR))
+		return IRQ_NONE;
+
+	/*
+	 * Handle the counter(s) overflow(s)
+	 */
+	regs = get_irq_regs();
+
+	csky_pmu_disable(&csky_pmu.pmu);
+
+	for (idx = 0; idx < CSKY_PMU_MAX_EVENTS; ++idx) {
+		struct perf_event *event = cpuc->events[idx];
+		struct hw_perf_event *hwc;
+
+		/* Ignore if we don't have an event. */
+		if (!event)
+			continue;
+		/*
+		 * We have a single interrupt for all counters. Check that
+		 * each counter has overflowed before we process it.
+		 */
+		if (!(cprcr(HPOFSR) & BIT(idx)))
+			continue;
+
+		hwc = &event->hw;
+		csky_perf_event_update(event, &event->hw);
+		perf_sample_data_init(&data, 0, hwc->last_period);
+		csky_pmu_event_set_period(event);
+
+		if (perf_event_overflow(event, &data, regs))
+			csky_pmu_stop_event(event);
+	}
+
+	csky_pmu_enable(&csky_pmu.pmu);
+
+	/*
+	 * Handle the pending perf events.
+	 *
+	 * Note: this call *must* be run with interrupts disabled. For
+	 * platforms that can have the PMU interrupts raised as an NMI, this
+	 * will not work.
+	 */
+	irq_work_run();
+
+	return IRQ_HANDLED;
+}
+
+static int csky_pmu_request_irq(irq_handler_t handler)
+{
+	int err, irqs;
+	struct platform_device *pmu_device = csky_pmu.plat_device;
+
+	if (!pmu_device)
+		return -ENODEV;
+
+	irqs = min(pmu_device->num_resources, num_possible_cpus());
+	if (irqs < 1) {
+		pr_err("no irqs for PMUs defined\n");
+		return -ENODEV;
+	}
+
+	csky_pmu_irq = platform_get_irq(pmu_device, 0);
+	if (csky_pmu_irq < 0)
+		return -ENODEV;
+	err = request_percpu_irq(csky_pmu_irq, handler, "csky-pmu",
+				 this_cpu_ptr(csky_pmu.hw_events));
+	if (err) {
+		pr_err("unable to request IRQ%d for CSKY PMU counters\n",
+		       csky_pmu_irq);
+		return err;
+	}
+
+	return 0;
+}
+
+static void csky_pmu_free_irq(void)
+{
+	int irq;
+	struct platform_device *pmu_device = csky_pmu.plat_device;
+
+	irq = platform_get_irq(pmu_device, 0);
+	if (irq >= 0)
+		free_percpu_irq(irq, this_cpu_ptr(csky_pmu.hw_events));
+}
+
+int init_hw_perf_events(void)
+{
+	csky_pmu.hw_events = alloc_percpu_gfp(struct pmu_hw_events,
+					      GFP_KERNEL);
+	if (!csky_pmu.hw_events) {
+		pr_info("failed to allocate per-cpu PMU data.\n");
+		return -ENOMEM;
+	}
+
+	csky_pmu.pmu = (struct pmu) {
+		.pmu_enable	= csky_pmu_enable,
+		.pmu_disable	= csky_pmu_disable,
+		.event_init	= csky_pmu_event_init,
+		.add		= csky_pmu_add,
+		.del		= csky_pmu_del,
+		.start		= csky_pmu_start,
+		.stop		= csky_pmu_stop,
+		.read		= csky_pmu_read,
+	};
+
+	memset((void *)hw_raw_read_mapping, 0,
+		sizeof(hw_raw_read_mapping[CSKY_PMU_MAX_EVENTS]));
+
+	hw_raw_read_mapping[0x1]  = csky_pmu_read_cc;
+	hw_raw_read_mapping[0x2]  = csky_pmu_read_ic;
+	hw_raw_read_mapping[0x3]  = csky_pmu_read_icac;
+	hw_raw_read_mapping[0x4]  = csky_pmu_read_icmc;
+	hw_raw_read_mapping[0x5]  = csky_pmu_read_dcac;
+	hw_raw_read_mapping[0x6]  = csky_pmu_read_dcmc;
+	hw_raw_read_mapping[0x7]  = csky_pmu_read_l2ac;
+	hw_raw_read_mapping[0x8]  = csky_pmu_read_l2mc;
+	hw_raw_read_mapping[0xa]  = csky_pmu_read_iutlbmc;
+	hw_raw_read_mapping[0xb]  = csky_pmu_read_dutlbmc;
+	hw_raw_read_mapping[0xc]  = csky_pmu_read_jtlbmc;
+	hw_raw_read_mapping[0xd]  = csky_pmu_read_softc;
+	hw_raw_read_mapping[0xe]  = csky_pmu_read_cbmc;
+	hw_raw_read_mapping[0xf]  = csky_pmu_read_cbic;
+	hw_raw_read_mapping[0x10] = csky_pmu_read_ibmc;
+	hw_raw_read_mapping[0x11] = csky_pmu_read_ibic;
+	hw_raw_read_mapping[0x12] = csky_pmu_read_lsfc;
+	hw_raw_read_mapping[0x13] = csky_pmu_read_sic;
+	hw_raw_read_mapping[0x14] = csky_pmu_read_dcrac;
+	hw_raw_read_mapping[0x15] = csky_pmu_read_dcrmc;
+	hw_raw_read_mapping[0x16] = csky_pmu_read_dcwac;
+	hw_raw_read_mapping[0x17] = csky_pmu_read_dcwmc;
+	hw_raw_read_mapping[0x18] = csky_pmu_read_l2rac;
+	hw_raw_read_mapping[0x19] = csky_pmu_read_l2rmc;
+	hw_raw_read_mapping[0x1a] = csky_pmu_read_l2wac;
+	hw_raw_read_mapping[0x1b] = csky_pmu_read_l2wmc;
+
+	memset((void *)hw_raw_write_mapping, 0,
+		sizeof(hw_raw_write_mapping[CSKY_PMU_MAX_EVENTS]));
+
+	hw_raw_write_mapping[0x1]  = csky_pmu_write_cc;
+	hw_raw_write_mapping[0x2]  = csky_pmu_write_ic;
+	hw_raw_write_mapping[0x3]  = csky_pmu_write_icac;
+	hw_raw_write_mapping[0x4]  = csky_pmu_write_icmc;
+	hw_raw_write_mapping[0x5]  = csky_pmu_write_dcac;
+	hw_raw_write_mapping[0x6]  = csky_pmu_write_dcmc;
+	hw_raw_write_mapping[0x7]  = csky_pmu_write_l2ac;
+	hw_raw_write_mapping[0x8]  = csky_pmu_write_l2mc;
+	hw_raw_write_mapping[0xa]  = csky_pmu_write_iutlbmc;
+	hw_raw_write_mapping[0xb]  = csky_pmu_write_dutlbmc;
+	hw_raw_write_mapping[0xc]  = csky_pmu_write_jtlbmc;
+	hw_raw_write_mapping[0xd]  = csky_pmu_write_softc;
+	hw_raw_write_mapping[0xe]  = csky_pmu_write_cbmc;
+	hw_raw_write_mapping[0xf]  = csky_pmu_write_cbic;
+	hw_raw_write_mapping[0x10] = csky_pmu_write_ibmc;
+	hw_raw_write_mapping[0x11] = csky_pmu_write_ibic;
+	hw_raw_write_mapping[0x12] = csky_pmu_write_lsfc;
+	hw_raw_write_mapping[0x13] = csky_pmu_write_sic;
+	hw_raw_write_mapping[0x14] = csky_pmu_write_dcrac;
+	hw_raw_write_mapping[0x15] = csky_pmu_write_dcrmc;
+	hw_raw_write_mapping[0x16] = csky_pmu_write_dcwac;
+	hw_raw_write_mapping[0x17] = csky_pmu_write_dcwmc;
+	hw_raw_write_mapping[0x18] = csky_pmu_write_l2rac;
+	hw_raw_write_mapping[0x19] = csky_pmu_write_l2rmc;
+	hw_raw_write_mapping[0x1a] = csky_pmu_write_l2wac;
+	hw_raw_write_mapping[0x1b] = csky_pmu_write_l2wmc;
+
+	return 0;
+}
+
+static int csky_pmu_starting_cpu(unsigned int cpu)
+{
+	enable_percpu_irq(csky_pmu_irq, 0);
+	return 0;
+}
+
+static int csky_pmu_dying_cpu(unsigned int cpu)
+{
+	disable_percpu_irq(csky_pmu_irq);
+	return 0;
+}
+
+int csky_pmu_device_probe(struct platform_device *pdev,
+			  const struct of_device_id *of_table)
+{
+	struct device_node *node = pdev->dev.of_node;
+	int ret;
+
+	ret = init_hw_perf_events();
+	if (ret) {
+		pr_notice("[perf] failed to probe PMU!\n");
+		return ret;
+	}
+
+	if (of_property_read_u32(node, "count-width",
+				 &csky_pmu.count_width)) {
+		csky_pmu.count_width = DEFAULT_COUNT_WIDTH;
+	}
+	csky_pmu.max_period = BIT_ULL(csky_pmu.count_width) - 1;
+
+	csky_pmu.plat_device = pdev;
+
+	/* Ensure the PMU has sane values out of reset. */
+	on_each_cpu(csky_pmu_reset, &csky_pmu, 1);
+
+	ret = csky_pmu_request_irq(csky_pmu_handle_irq);
+	if (ret) {
+		csky_pmu.pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
+		pr_notice("[perf] PMU request irq fail!\n");
+	}
+
+	ret = cpuhp_setup_state(CPUHP_AP_PERF_ONLINE, "AP_PERF_ONLINE",
+				csky_pmu_starting_cpu,
+				csky_pmu_dying_cpu);
+	if (ret) {
+		csky_pmu_free_irq();
+		free_percpu(csky_pmu.hw_events);
+		return ret;
+	}
+
+	ret = perf_pmu_register(&csky_pmu.pmu, "cpu", PERF_TYPE_RAW);
+	if (ret) {
+		csky_pmu_free_irq();
+		free_percpu(csky_pmu.hw_events);
+	}
+
+	return ret;
+}
+
+static const struct of_device_id csky_pmu_of_device_ids[] = {
+	{.compatible = "csky,csky-pmu"},
+	{},
+};
+
+static int csky_pmu_dev_probe(struct platform_device *pdev)
+{
+	return csky_pmu_device_probe(pdev, csky_pmu_of_device_ids);
+}
+
+static struct platform_driver csky_pmu_driver = {
+	.driver = {
+		   .name = "csky-pmu",
+		   .of_match_table = csky_pmu_of_device_ids,
+		   },
+	.probe = csky_pmu_dev_probe,
+};
+
+static int __init csky_pmu_probe(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&csky_pmu_driver);
+	if (ret)
+		pr_notice("[perf] PMU initialization failed\n");
+	else
+		pr_notice("[perf] PMU initialization done\n");
+
+	return ret;
+}
+
+device_initcall(csky_pmu_probe);
diff --git a/arch/csky/kernel/perf_regs.c b/arch/csky/kernel/perf_regs.c
new file mode 100644
index 000000000..09b7f88a2
--- /dev/null
+++ b/arch/csky/kernel/perf_regs.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/perf_event.h>
+#include <linux/bug.h>
+#include <asm/perf_regs.h>
+#include <asm/ptrace.h>
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+	if (WARN_ON_ONCE((u32)idx >= PERF_REG_CSKY_MAX))
+		return 0;
+
+	return (u64)*((u32 *)regs + idx);
+}
+
+#define REG_RESERVED (~((1ULL << PERF_REG_CSKY_MAX) - 1))
+
+int perf_reg_validate(u64 mask)
+{
+	if (!mask || mask & REG_RESERVED)
+		return -EINVAL;
+
+	return 0;
+}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+	return PERF_SAMPLE_REGS_ABI_32;
+}
+
+void perf_get_regs_user(struct perf_regs *regs_user,
+			struct pt_regs *regs)
+{
+	regs_user->regs = task_pt_regs(current);
+	regs_user->abi = perf_reg_abi(current);
+}
diff --git a/arch/csky/kernel/power.c b/arch/csky/kernel/power.c
new file mode 100644
index 000000000..923ee4e38
--- /dev/null
+++ b/arch/csky/kernel/power.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/reboot.h>
+
+void (*pm_power_off)(void);
+EXPORT_SYMBOL(pm_power_off);
+
+void machine_power_off(void)
+{
+	local_irq_disable();
+	if (pm_power_off)
+		pm_power_off();
+	asm volatile ("bkpt");
+}
+
+void machine_halt(void)
+{
+	local_irq_disable();
+	if (pm_power_off)
+		pm_power_off();
+	asm volatile ("bkpt");
+}
+
+void machine_restart(char *cmd)
+{
+	local_irq_disable();
+	do_kernel_restart(cmd);
+	asm volatile ("bkpt");
+}
diff --git a/arch/csky/kernel/probes/Makefile b/arch/csky/kernel/probes/Makefile
new file mode 100644
index 000000000..1c7c6e6cb
--- /dev/null
+++ b/arch/csky/kernel/probes/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_KPROBES)		+= kprobes.o decode-insn.o simulate-insn.o
+obj-$(CONFIG_KPROBES)		+= kprobes_trampoline.o
+obj-$(CONFIG_KPROBES_ON_FTRACE)	+= ftrace.o
+obj-$(CONFIG_UPROBES)		+= uprobes.o decode-insn.o simulate-insn.o
+
+CFLAGS_REMOVE_simulate-insn.o = $(CC_FLAGS_FTRACE)
diff --git a/arch/csky/kernel/probes/decode-insn.c b/arch/csky/kernel/probes/decode-insn.c
new file mode 100644
index 000000000..bbc4edc25
--- /dev/null
+++ b/arch/csky/kernel/probes/decode-insn.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <asm/sections.h>
+
+#include "decode-insn.h"
+#include "simulate-insn.h"
+
+/* Return:
+ *   INSN_REJECTED     If instruction is one not allowed to kprobe,
+ *   INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
+ */
+enum probe_insn __kprobes
+csky_probe_decode_insn(probe_opcode_t *addr, struct arch_probe_insn *api)
+{
+	probe_opcode_t insn = le32_to_cpu(*addr);
+
+	CSKY_INSN_SET_SIMULATE(br16,		insn);
+	CSKY_INSN_SET_SIMULATE(bt16,		insn);
+	CSKY_INSN_SET_SIMULATE(bf16,		insn);
+	CSKY_INSN_SET_SIMULATE(jmp16,		insn);
+	CSKY_INSN_SET_SIMULATE(jsr16,		insn);
+	CSKY_INSN_SET_SIMULATE(lrw16,		insn);
+	CSKY_INSN_SET_SIMULATE(pop16,		insn);
+
+	CSKY_INSN_SET_SIMULATE(br32,		insn);
+	CSKY_INSN_SET_SIMULATE(bt32,		insn);
+	CSKY_INSN_SET_SIMULATE(bf32,		insn);
+	CSKY_INSN_SET_SIMULATE(jmp32,		insn);
+	CSKY_INSN_SET_SIMULATE(jsr32,		insn);
+	CSKY_INSN_SET_SIMULATE(lrw32,		insn);
+	CSKY_INSN_SET_SIMULATE(pop32,		insn);
+
+	CSKY_INSN_SET_SIMULATE(bez32,		insn);
+	CSKY_INSN_SET_SIMULATE(bnez32,		insn);
+	CSKY_INSN_SET_SIMULATE(bnezad32,	insn);
+	CSKY_INSN_SET_SIMULATE(bhsz32,		insn);
+	CSKY_INSN_SET_SIMULATE(bhz32,		insn);
+	CSKY_INSN_SET_SIMULATE(blsz32,		insn);
+	CSKY_INSN_SET_SIMULATE(blz32,		insn);
+	CSKY_INSN_SET_SIMULATE(bsr32,		insn);
+	CSKY_INSN_SET_SIMULATE(jmpi32,		insn);
+	CSKY_INSN_SET_SIMULATE(jsri32,		insn);
+
+	return INSN_GOOD;
+}
diff --git a/arch/csky/kernel/probes/decode-insn.h b/arch/csky/kernel/probes/decode-insn.h
new file mode 100644
index 000000000..9c4ad48fe
--- /dev/null
+++ b/arch/csky/kernel/probes/decode-insn.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef __CSKY_KERNEL_KPROBES_DECODE_INSN_H
+#define __CSKY_KERNEL_KPROBES_DECODE_INSN_H
+
+#include <asm/sections.h>
+#include <asm/kprobes.h>
+
+enum probe_insn {
+	INSN_REJECTED,
+	INSN_GOOD_NO_SLOT,
+	INSN_GOOD,
+};
+
+#define is_insn32(insn) ((insn & 0xc000) == 0xc000)
+
+enum probe_insn __kprobes
+csky_probe_decode_insn(probe_opcode_t *addr, struct arch_probe_insn *asi);
+
+#endif /* __CSKY_KERNEL_KPROBES_DECODE_INSN_H */
diff --git a/arch/csky/kernel/probes/ftrace.c b/arch/csky/kernel/probes/ftrace.c
new file mode 100644
index 000000000..5264763d0
--- /dev/null
+++ b/arch/csky/kernel/probes/ftrace.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kprobes.h>
+
+int arch_check_ftrace_location(struct kprobe *p)
+{
+	if (ftrace_location((unsigned long)p->addr))
+		p->flags |= KPROBE_FLAG_FTRACE;
+	return 0;
+}
+
+/* Ftrace callback handler for kprobes -- called under preepmt disabed */
+void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
+			   struct ftrace_ops *ops, struct pt_regs *regs)
+{
+	bool lr_saver = false;
+	struct kprobe *p;
+	struct kprobe_ctlblk *kcb;
+
+	/* Preempt is disabled by ftrace */
+	p = get_kprobe((kprobe_opcode_t *)ip);
+	if (!p) {
+		p = get_kprobe((kprobe_opcode_t *)(ip - MCOUNT_INSN_SIZE));
+		if (unlikely(!p) || kprobe_disabled(p))
+			return;
+		lr_saver = true;
+	}
+
+	kcb = get_kprobe_ctlblk();
+	if (kprobe_running()) {
+		kprobes_inc_nmissed_count(p);
+	} else {
+		unsigned long orig_ip = instruction_pointer(regs);
+
+		if (lr_saver)
+			ip -= MCOUNT_INSN_SIZE;
+		instruction_pointer_set(regs, ip);
+		__this_cpu_write(current_kprobe, p);
+		kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+		if (!p->pre_handler || !p->pre_handler(p, regs)) {
+			/*
+			 * Emulate singlestep (and also recover regs->pc)
+			 * as if there is a nop
+			 */
+			instruction_pointer_set(regs,
+				(unsigned long)p->addr + MCOUNT_INSN_SIZE);
+			if (unlikely(p->post_handler)) {
+				kcb->kprobe_status = KPROBE_HIT_SSDONE;
+				p->post_handler(p, regs, 0);
+			}
+			instruction_pointer_set(regs, orig_ip);
+		}
+		/*
+		 * If pre_handler returns !0, it changes regs->pc. We have to
+		 * skip emulating post_handler.
+		 */
+		__this_cpu_write(current_kprobe, NULL);
+	}
+}
+NOKPROBE_SYMBOL(kprobe_ftrace_handler);
+
+int arch_prepare_kprobe_ftrace(struct kprobe *p)
+{
+	p->ainsn.api.insn = NULL;
+	return 0;
+}
diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kprobes.c
new file mode 100644
index 000000000..79272dde7
--- /dev/null
+++ b/arch/csky/kernel/probes/kprobes.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/kprobes.h>
+#include <linux/extable.h>
+#include <linux/slab.h>
+#include <linux/stop_machine.h>
+#include <asm/ptrace.h>
+#include <linux/uaccess.h>
+#include <asm/sections.h>
+#include <asm/cacheflush.h>
+
+#include "decode-insn.h"
+
+DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
+DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+
+static void __kprobes
+post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *);
+
+struct csky_insn_patch {
+	kprobe_opcode_t	*addr;
+	u32		opcode;
+	atomic_t	cpu_count;
+};
+
+static int __kprobes patch_text_cb(void *priv)
+{
+	struct csky_insn_patch *param = priv;
+	unsigned int addr = (unsigned int)param->addr;
+
+	if (atomic_inc_return(&param->cpu_count) == num_online_cpus()) {
+		*(u16 *) addr = cpu_to_le16(param->opcode);
+		dcache_wb_range(addr, addr + 2);
+		atomic_inc(&param->cpu_count);
+	} else {
+		while (atomic_read(&param->cpu_count) <= num_online_cpus())
+			cpu_relax();
+	}
+
+	icache_inv_range(addr, addr + 2);
+
+	return 0;
+}
+
+static int __kprobes patch_text(kprobe_opcode_t *addr, u32 opcode)
+{
+	struct csky_insn_patch param = { addr, opcode, ATOMIC_INIT(0) };
+
+	return stop_machine_cpuslocked(patch_text_cb, &param, cpu_online_mask);
+}
+
+static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
+{
+	unsigned long offset = is_insn32(p->opcode) ? 4 : 2;
+
+	p->ainsn.api.restore = (unsigned long)p->addr + offset;
+
+	patch_text(p->ainsn.api.insn, p->opcode);
+}
+
+static void __kprobes arch_prepare_simulate(struct kprobe *p)
+{
+	p->ainsn.api.restore = 0;
+}
+
+static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
+{
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+
+	if (p->ainsn.api.handler)
+		p->ainsn.api.handler((u32)p->opcode, (long)p->addr, regs);
+
+	post_kprobe_handler(kcb, regs);
+}
+
+int __kprobes arch_prepare_kprobe(struct kprobe *p)
+{
+	unsigned long probe_addr = (unsigned long)p->addr;
+
+	if (probe_addr & 0x1) {
+		pr_warn("Address not aligned.\n");
+		return -EINVAL;
+	}
+
+	/* copy instruction */
+	p->opcode = le32_to_cpu(*p->addr);
+
+	/* decode instruction */
+	switch (csky_probe_decode_insn(p->addr, &p->ainsn.api)) {
+	case INSN_REJECTED:	/* insn not supported */
+		return -EINVAL;
+
+	case INSN_GOOD_NO_SLOT:	/* insn need simulation */
+		p->ainsn.api.insn = NULL;
+		break;
+
+	case INSN_GOOD:	/* instruction uses slot */
+		p->ainsn.api.insn = get_insn_slot();
+		if (!p->ainsn.api.insn)
+			return -ENOMEM;
+		break;
+	}
+
+	/* prepare the instruction */
+	if (p->ainsn.api.insn)
+		arch_prepare_ss_slot(p);
+	else
+		arch_prepare_simulate(p);
+
+	return 0;
+}
+
+/* install breakpoint in text */
+void __kprobes arch_arm_kprobe(struct kprobe *p)
+{
+	patch_text(p->addr, USR_BKPT);
+}
+
+/* remove breakpoint from text */
+void __kprobes arch_disarm_kprobe(struct kprobe *p)
+{
+	patch_text(p->addr, p->opcode);
+}
+
+void __kprobes arch_remove_kprobe(struct kprobe *p)
+{
+	if (p->ainsn.api.insn) {
+		free_insn_slot(p->ainsn.api.insn, 0);
+		p->ainsn.api.insn = NULL;
+	}
+}
+
+static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
+{
+	kcb->prev_kprobe.kp = kprobe_running();
+	kcb->prev_kprobe.status = kcb->kprobe_status;
+}
+
+static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
+{
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
+	kcb->kprobe_status = kcb->prev_kprobe.status;
+}
+
+static void __kprobes set_current_kprobe(struct kprobe *p)
+{
+	__this_cpu_write(current_kprobe, p);
+}
+
+/*
+ * Interrupts need to be disabled before single-step mode is set, and not
+ * reenabled until after single-step mode ends.
+ * Without disabling interrupt on local CPU, there is a chance of
+ * interrupt occurrence in the period of exception return and  start of
+ * out-of-line single-step, that result in wrongly single stepping
+ * into the interrupt handler.
+ */
+static void __kprobes kprobes_save_local_irqflag(struct kprobe_ctlblk *kcb,
+						struct pt_regs *regs)
+{
+	kcb->saved_sr = regs->sr;
+	regs->sr &= ~BIT(6);
+}
+
+static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb,
+						struct pt_regs *regs)
+{
+	regs->sr = kcb->saved_sr;
+}
+
+static void __kprobes
+set_ss_context(struct kprobe_ctlblk *kcb, unsigned long addr, struct kprobe *p)
+{
+	unsigned long offset = is_insn32(p->opcode) ? 4 : 2;
+
+	kcb->ss_ctx.ss_pending = true;
+	kcb->ss_ctx.match_addr = addr + offset;
+}
+
+static void __kprobes clear_ss_context(struct kprobe_ctlblk *kcb)
+{
+	kcb->ss_ctx.ss_pending = false;
+	kcb->ss_ctx.match_addr = 0;
+}
+
+#define TRACE_MODE_SI		BIT(14)
+#define TRACE_MODE_MASK		~(0x3 << 14)
+#define TRACE_MODE_RUN		0
+
+static void __kprobes setup_singlestep(struct kprobe *p,
+				       struct pt_regs *regs,
+				       struct kprobe_ctlblk *kcb, int reenter)
+{
+	unsigned long slot;
+
+	if (reenter) {
+		save_previous_kprobe(kcb);
+		set_current_kprobe(p);
+		kcb->kprobe_status = KPROBE_REENTER;
+	} else {
+		kcb->kprobe_status = KPROBE_HIT_SS;
+	}
+
+	if (p->ainsn.api.insn) {
+		/* prepare for single stepping */
+		slot = (unsigned long)p->ainsn.api.insn;
+
+		set_ss_context(kcb, slot, p);	/* mark pending ss */
+
+		/* IRQs and single stepping do not mix well. */
+		kprobes_save_local_irqflag(kcb, regs);
+		regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_SI;
+		instruction_pointer_set(regs, slot);
+	} else {
+		/* insn simulation */
+		arch_simulate_insn(p, regs);
+	}
+}
+
+static int __kprobes reenter_kprobe(struct kprobe *p,
+				    struct pt_regs *regs,
+				    struct kprobe_ctlblk *kcb)
+{
+	switch (kcb->kprobe_status) {
+	case KPROBE_HIT_SSDONE:
+	case KPROBE_HIT_ACTIVE:
+		kprobes_inc_nmissed_count(p);
+		setup_singlestep(p, regs, kcb, 1);
+		break;
+	case KPROBE_HIT_SS:
+	case KPROBE_REENTER:
+		pr_warn("Unrecoverable kprobe detected.\n");
+		dump_kprobe(p);
+		BUG();
+		break;
+	default:
+		WARN_ON(1);
+		return 0;
+	}
+
+	return 1;
+}
+
+static void __kprobes
+post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs)
+{
+	struct kprobe *cur = kprobe_running();
+
+	if (!cur)
+		return;
+
+	/* return addr restore if non-branching insn */
+	if (cur->ainsn.api.restore != 0)
+		regs->pc = cur->ainsn.api.restore;
+
+	/* restore back original saved kprobe variables and continue */
+	if (kcb->kprobe_status == KPROBE_REENTER) {
+		restore_previous_kprobe(kcb);
+		return;
+	}
+
+	/* call post handler */
+	kcb->kprobe_status = KPROBE_HIT_SSDONE;
+	if (cur->post_handler)	{
+		/* post_handler can hit breakpoint and single step
+		 * again, so we enable D-flag for recursive exception.
+		 */
+		cur->post_handler(cur, regs, 0);
+	}
+
+	reset_current_kprobe();
+}
+
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr)
+{
+	struct kprobe *cur = kprobe_running();
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+
+	switch (kcb->kprobe_status) {
+	case KPROBE_HIT_SS:
+	case KPROBE_REENTER:
+		/*
+		 * We are here because the instruction being single
+		 * stepped caused a page fault. We reset the current
+		 * kprobe and the ip points back to the probe address
+		 * and allow the page fault handler to continue as a
+		 * normal page fault.
+		 */
+		regs->pc = (unsigned long) cur->addr;
+		if (!instruction_pointer(regs))
+			BUG();
+
+		if (kcb->kprobe_status == KPROBE_REENTER)
+			restore_previous_kprobe(kcb);
+		else
+			reset_current_kprobe();
+
+		break;
+	case KPROBE_HIT_ACTIVE:
+	case KPROBE_HIT_SSDONE:
+		/*
+		 * We increment the nmissed count for accounting,
+		 * we can also use npre/npostfault count for accounting
+		 * these specific fault cases.
+		 */
+		kprobes_inc_nmissed_count(cur);
+
+		/*
+		 * We come here because instructions in the pre/post
+		 * handler caused the page_fault, this could happen
+		 * if handler tries to access user space by
+		 * copy_from_user(), get_user() etc. Let the
+		 * user-specified handler try to fix it first.
+		 */
+		if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
+			return 1;
+
+		/*
+		 * In case the user-specified fault handler returned
+		 * zero, try to fix up.
+		 */
+		if (fixup_exception(regs))
+			return 1;
+	}
+	return 0;
+}
+
+int __kprobes
+kprobe_breakpoint_handler(struct pt_regs *regs)
+{
+	struct kprobe *p, *cur_kprobe;
+	struct kprobe_ctlblk *kcb;
+	unsigned long addr = instruction_pointer(regs);
+
+	kcb = get_kprobe_ctlblk();
+	cur_kprobe = kprobe_running();
+
+	p = get_kprobe((kprobe_opcode_t *) addr);
+
+	if (p) {
+		if (cur_kprobe) {
+			if (reenter_kprobe(p, regs, kcb))
+				return 1;
+		} else {
+			/* Probe hit */
+			set_current_kprobe(p);
+			kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+
+			/*
+			 * If we have no pre-handler or it returned 0, we
+			 * continue with normal processing.  If we have a
+			 * pre-handler and it returned non-zero, it will
+			 * modify the execution path and no need to single
+			 * stepping. Let's just reset current kprobe and exit.
+			 *
+			 * pre_handler can hit a breakpoint and can step thru
+			 * before return.
+			 */
+			if (!p->pre_handler || !p->pre_handler(p, regs))
+				setup_singlestep(p, regs, kcb, 0);
+			else
+				reset_current_kprobe();
+		}
+		return 1;
+	}
+
+	/*
+	 * The breakpoint instruction was removed right
+	 * after we hit it.  Another cpu has removed
+	 * either a probepoint or a debugger breakpoint
+	 * at this address.  In either case, no further
+	 * handling of this interrupt is appropriate.
+	 * Return back to original instruction, and continue.
+	 */
+	return 0;
+}
+
+int __kprobes
+kprobe_single_step_handler(struct pt_regs *regs)
+{
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+
+	if ((kcb->ss_ctx.ss_pending)
+	    && (kcb->ss_ctx.match_addr == instruction_pointer(regs))) {
+		clear_ss_context(kcb);	/* clear pending ss */
+
+		kprobes_restore_local_irqflag(kcb, regs);
+		regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_RUN;
+
+		post_kprobe_handler(kcb, regs);
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * Provide a blacklist of symbols identifying ranges which cannot be kprobed.
+ * This blacklist is exposed to userspace via debugfs (kprobes/blacklist).
+ */
+int __init arch_populate_kprobe_blacklist(void)
+{
+	int ret;
+
+	ret = kprobe_add_area_blacklist((unsigned long)__irqentry_text_start,
+					(unsigned long)__irqentry_text_end);
+	return ret;
+}
+
+void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs)
+{
+	return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);
+}
+
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
+				      struct pt_regs *regs)
+{
+	ri->ret_addr = (kprobe_opcode_t *)regs->lr;
+	ri->fp = NULL;
+	regs->lr = (unsigned long) &kretprobe_trampoline;
+}
+
+int __kprobes arch_trampoline_kprobe(struct kprobe *p)
+{
+	return 0;
+}
+
+int __init arch_init_kprobes(void)
+{
+	return 0;
+}
diff --git a/arch/csky/kernel/probes/kprobes_trampoline.S b/arch/csky/kernel/probes/kprobes_trampoline.S
new file mode 100644
index 000000000..b1fe3af24
--- /dev/null
+++ b/arch/csky/kernel/probes/kprobes_trampoline.S
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#include <linux/linkage.h>
+
+#include <abi/entry.h>
+
+ENTRY(kretprobe_trampoline)
+	SAVE_REGS_FTRACE
+
+	mov	a0, sp /* pt_regs */
+
+	jbsr	trampoline_probe_handler
+
+	/* use the result as the return-address */
+	mov	lr, a0
+
+	RESTORE_REGS_FTRACE
+	rts
+ENDPROC(kretprobe_trampoline)
diff --git a/arch/csky/kernel/probes/simulate-insn.c b/arch/csky/kernel/probes/simulate-insn.c
new file mode 100644
index 000000000..4e464fed5
--- /dev/null
+++ b/arch/csky/kernel/probes/simulate-insn.c
@@ -0,0 +1,398 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+
+#include "decode-insn.h"
+#include "simulate-insn.h"
+
+static inline bool csky_insn_reg_get_val(struct pt_regs *regs,
+					 unsigned long index,
+					 unsigned long *ptr)
+{
+	if (index < 14)
+		*ptr = *(&regs->a0 + index);
+
+	if (index > 15 && index < 31)
+		*ptr = *(&regs->exregs[0] + index - 16);
+
+	switch (index) {
+	case 14:
+		*ptr = regs->usp;
+		break;
+	case 15:
+		*ptr = regs->lr;
+		break;
+	case 31:
+		*ptr = regs->tls;
+		break;
+	default:
+		goto fail;
+	}
+
+	return true;
+fail:
+	return false;
+}
+
+static inline bool csky_insn_reg_set_val(struct pt_regs *regs,
+					 unsigned long index,
+					 unsigned long val)
+{
+	if (index < 14)
+		*(&regs->a0 + index) = val;
+
+	if (index > 15 && index < 31)
+		*(&regs->exregs[0] + index - 16) = val;
+
+	switch (index) {
+	case 14:
+		regs->usp = val;
+		break;
+	case 15:
+		regs->lr = val;
+		break;
+	case 31:
+		regs->tls = val;
+		break;
+	default:
+		goto fail;
+	}
+
+	return true;
+fail:
+	return false;
+}
+
+void __kprobes
+simulate_br16(u32 opcode, long addr, struct pt_regs *regs)
+{
+	instruction_pointer_set(regs,
+		addr + sign_extend32((opcode & 0x3ff) << 1, 9));
+}
+
+void __kprobes
+simulate_br32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	instruction_pointer_set(regs,
+		addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+}
+
+void __kprobes
+simulate_bt16(u32 opcode, long addr, struct pt_regs *regs)
+{
+	if (regs->sr & 1)
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0x3ff) << 1, 9));
+	else
+		instruction_pointer_set(regs, addr + 2);
+}
+
+void __kprobes
+simulate_bt32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	if (regs->sr & 1)
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+	else
+		instruction_pointer_set(regs, addr + 4);
+}
+
+void __kprobes
+simulate_bf16(u32 opcode, long addr, struct pt_regs *regs)
+{
+	if (!(regs->sr & 1))
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0x3ff) << 1, 9));
+	else
+		instruction_pointer_set(regs, addr + 2);
+}
+
+void __kprobes
+simulate_bf32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	if (!(regs->sr & 1))
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+	else
+		instruction_pointer_set(regs, addr + 4);
+}
+
+void __kprobes
+simulate_jmp16(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = (opcode >> 2) & 0xf;
+
+	csky_insn_reg_get_val(regs, tmp, &tmp);
+
+	instruction_pointer_set(regs, tmp & 0xfffffffe);
+}
+
+void __kprobes
+simulate_jmp32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = opcode & 0x1f;
+
+	csky_insn_reg_get_val(regs, tmp, &tmp);
+
+	instruction_pointer_set(regs, tmp & 0xfffffffe);
+}
+
+void __kprobes
+simulate_jsr16(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = (opcode >> 2) & 0xf;
+
+	csky_insn_reg_get_val(regs, tmp, &tmp);
+
+	regs->lr = addr + 2;
+
+	instruction_pointer_set(regs, tmp & 0xfffffffe);
+}
+
+void __kprobes
+simulate_jsr32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = opcode & 0x1f;
+
+	csky_insn_reg_get_val(regs, tmp, &tmp);
+
+	regs->lr = addr + 4;
+
+	instruction_pointer_set(regs, tmp & 0xfffffffe);
+}
+
+void __kprobes
+simulate_lrw16(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long val;
+	unsigned long tmp = (opcode & 0x300) >> 3;
+	unsigned long offset = ((opcode & 0x1f) | tmp) << 2;
+
+	tmp = (opcode & 0xe0) >> 5;
+
+	val = *(unsigned int *)(instruction_pointer(regs) + offset);
+
+	csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_lrw32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long val;
+	unsigned long offset = (opcode & 0xffff0000) >> 14;
+	unsigned long tmp = opcode & 0x0000001f;
+
+	val = *(unsigned int *)
+		((instruction_pointer(regs) + offset) & 0xfffffffc);
+
+	csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_pop16(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long *tmp = (unsigned long *)regs->usp;
+	int i;
+
+	for (i = 0; i < (opcode & 0xf); i++) {
+		csky_insn_reg_set_val(regs, i + 4, *tmp);
+		tmp += 1;
+	}
+
+	if (opcode & 0x10) {
+		csky_insn_reg_set_val(regs, 15, *tmp);
+		tmp += 1;
+	}
+
+	regs->usp = (unsigned long)tmp;
+
+	instruction_pointer_set(regs, regs->lr);
+}
+
+void __kprobes
+simulate_pop32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long *tmp = (unsigned long *)regs->usp;
+	int i;
+
+	for (i = 0; i < ((opcode & 0xf0000) >> 16); i++) {
+		csky_insn_reg_set_val(regs, i + 4, *tmp);
+		tmp += 1;
+	}
+
+	if (opcode & 0x100000) {
+		csky_insn_reg_set_val(regs, 15, *tmp);
+		tmp += 1;
+	}
+
+	for (i = 0; i < ((opcode & 0xe00000) >> 21); i++) {
+		csky_insn_reg_set_val(regs, i + 16, *tmp);
+		tmp += 1;
+	}
+
+	if (opcode & 0x1000000) {
+		csky_insn_reg_set_val(regs, 29, *tmp);
+		tmp += 1;
+	}
+
+	regs->usp = (unsigned long)tmp;
+
+	instruction_pointer_set(regs, regs->lr);
+}
+
+void __kprobes
+simulate_bez32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = opcode & 0x1f;
+
+	csky_insn_reg_get_val(regs, tmp, &tmp);
+
+	if (tmp == 0) {
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+	} else
+		instruction_pointer_set(regs, addr + 4);
+}
+
+void __kprobes
+simulate_bnez32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = opcode & 0x1f;
+
+	csky_insn_reg_get_val(regs, tmp, &tmp);
+
+	if (tmp != 0) {
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+	} else
+		instruction_pointer_set(regs, addr + 4);
+}
+
+void __kprobes
+simulate_bnezad32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = opcode & 0x1f;
+	unsigned long val;
+
+	csky_insn_reg_get_val(regs, tmp, &val);
+
+	val -= 1;
+
+	if (val > 0) {
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+	} else
+		instruction_pointer_set(regs, addr + 4);
+
+	csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_bhsz32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = opcode & 0x1f;
+	unsigned long val;
+
+	csky_insn_reg_get_val(regs, tmp, &val);
+
+	if (val >= 0) {
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+	} else
+		instruction_pointer_set(regs, addr + 4);
+
+	csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_bhz32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = opcode & 0x1f;
+	unsigned long val;
+
+	csky_insn_reg_get_val(regs, tmp, &val);
+
+	if (val > 0) {
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+	} else
+		instruction_pointer_set(regs, addr + 4);
+
+	csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_blsz32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = opcode & 0x1f;
+	unsigned long val;
+
+	csky_insn_reg_get_val(regs, tmp, &val);
+
+	if (val <= 0) {
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+	} else
+		instruction_pointer_set(regs, addr + 4);
+
+	csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_blz32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp = opcode & 0x1f;
+	unsigned long val;
+
+	csky_insn_reg_get_val(regs, tmp, &val);
+
+	if (val < 0) {
+		instruction_pointer_set(regs,
+			addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+	} else
+		instruction_pointer_set(regs, addr + 4);
+
+	csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_bsr32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long tmp;
+
+	tmp = (opcode & 0xffff) << 16;
+	tmp |= (opcode & 0xffff0000) >> 16;
+
+	instruction_pointer_set(regs,
+		addr + sign_extend32((tmp & 0x3ffffff) << 1, 15));
+
+	regs->lr = addr + 4;
+}
+
+void __kprobes
+simulate_jmpi32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long val;
+	unsigned long offset = ((opcode & 0xffff0000) >> 14);
+
+	val = *(unsigned int *)
+		((instruction_pointer(regs) + offset) & 0xfffffffc);
+
+	instruction_pointer_set(regs, val);
+}
+
+void __kprobes
+simulate_jsri32(u32 opcode, long addr, struct pt_regs *regs)
+{
+	unsigned long val;
+	unsigned long offset = ((opcode & 0xffff0000) >> 14);
+
+	val = *(unsigned int *)
+		((instruction_pointer(regs) + offset) & 0xfffffffc);
+
+	regs->lr = addr + 4;
+
+	instruction_pointer_set(regs, val);
+}
diff --git a/arch/csky/kernel/probes/simulate-insn.h b/arch/csky/kernel/probes/simulate-insn.h
new file mode 100644
index 000000000..ba4cb7ef0
--- /dev/null
+++ b/arch/csky/kernel/probes/simulate-insn.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef __CSKY_KERNEL_PROBES_SIMULATE_INSN_H
+#define __CSKY_KERNEL_PROBES_SIMULATE_INSN_H
+
+#define __CSKY_INSN_FUNCS(name, mask, val)				\
+static __always_inline bool csky_insn_is_##name(probe_opcode_t code)	\
+{									\
+	BUILD_BUG_ON(~(mask) & (val));					\
+	return (code & (mask)) == (val);				\
+}									\
+void simulate_##name(u32 opcode, long addr, struct pt_regs *regs);
+
+#define CSKY_INSN_SET_SIMULATE(name, code)				\
+	do {								\
+		if (csky_insn_is_##name(code)) {			\
+			api->handler = simulate_##name;			\
+			return INSN_GOOD_NO_SLOT;			\
+		}							\
+	} while (0)
+
+__CSKY_INSN_FUNCS(br16,		0xfc00, 0x0400)
+__CSKY_INSN_FUNCS(bt16,		0xfc00, 0x0800)
+__CSKY_INSN_FUNCS(bf16,		0xfc00, 0x0c00)
+__CSKY_INSN_FUNCS(jmp16,	0xffc3, 0x7800)
+__CSKY_INSN_FUNCS(jsr16,	0xffc3, 0x7801)
+__CSKY_INSN_FUNCS(lrw16,	0xfc00, 0x1000)
+__CSKY_INSN_FUNCS(pop16,	0xffe0, 0x1480)
+
+__CSKY_INSN_FUNCS(br32,		0x0000ffff, 0x0000e800)
+__CSKY_INSN_FUNCS(bt32,		0x0000ffff, 0x0000e860)
+__CSKY_INSN_FUNCS(bf32,		0x0000ffff, 0x0000e840)
+__CSKY_INSN_FUNCS(jmp32,	0xffffffe0, 0x0000e8c0)
+__CSKY_INSN_FUNCS(jsr32,	0xffffffe0, 0x0000e8e0)
+__CSKY_INSN_FUNCS(lrw32,	0x0000ffe0, 0x0000ea80)
+__CSKY_INSN_FUNCS(pop32,	0xfe00ffff, 0x0000ebc0)
+
+__CSKY_INSN_FUNCS(bez32,	0x0000ffe0, 0x0000e900)
+__CSKY_INSN_FUNCS(bnez32,	0x0000ffe0, 0x0000e920)
+__CSKY_INSN_FUNCS(bnezad32,	0x0000ffe0, 0x0000e820)
+__CSKY_INSN_FUNCS(bhsz32,	0x0000ffe0, 0x0000e9a0)
+__CSKY_INSN_FUNCS(bhz32,	0x0000ffe0, 0x0000e940)
+__CSKY_INSN_FUNCS(blsz32,	0x0000ffe0, 0x0000e960)
+__CSKY_INSN_FUNCS(blz32,	0x0000ffe0, 0x0000e980)
+__CSKY_INSN_FUNCS(bsr32,	0x0000fc00, 0x0000e000)
+__CSKY_INSN_FUNCS(jmpi32,	0x0000ffff, 0x0000eac0)
+__CSKY_INSN_FUNCS(jsri32,	0x0000ffff, 0x0000eae0)
+
+#endif /* __CSKY_KERNEL_PROBES_SIMULATE_INSN_H */
diff --git a/arch/csky/kernel/probes/uprobes.c b/arch/csky/kernel/probes/uprobes.c
new file mode 100644
index 000000000..1a9e0961b
--- /dev/null
+++ b/arch/csky/kernel/probes/uprobes.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2014-2016 Pratyush Anand <panand@redhat.com>
+ */
+#include <linux/highmem.h>
+#include <linux/ptrace.h>
+#include <linux/uprobes.h>
+#include <asm/cacheflush.h>
+
+#include "decode-insn.h"
+
+#define UPROBE_TRAP_NR	UINT_MAX
+
+bool is_swbp_insn(uprobe_opcode_t *insn)
+{
+	return (*insn & 0xffff) == UPROBE_SWBP_INSN;
+}
+
+unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)
+{
+	return instruction_pointer(regs);
+}
+
+int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
+		unsigned long addr)
+{
+	probe_opcode_t insn;
+
+	insn = *(probe_opcode_t *)(&auprobe->insn[0]);
+
+	auprobe->insn_size = is_insn32(insn) ? 4 : 2;
+
+	switch (csky_probe_decode_insn(&insn, &auprobe->api)) {
+	case INSN_REJECTED:
+		return -EINVAL;
+
+	case INSN_GOOD_NO_SLOT:
+		auprobe->simulate = true;
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+	struct uprobe_task *utask = current->utask;
+
+	utask->autask.saved_trap_no = current->thread.trap_no;
+	current->thread.trap_no = UPROBE_TRAP_NR;
+
+	instruction_pointer_set(regs, utask->xol_vaddr);
+
+	user_enable_single_step(current);
+
+	return 0;
+}
+
+int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+	struct uprobe_task *utask = current->utask;
+
+	WARN_ON_ONCE(current->thread.trap_no != UPROBE_TRAP_NR);
+
+	instruction_pointer_set(regs, utask->vaddr + auprobe->insn_size);
+
+	user_disable_single_step(current);
+
+	return 0;
+}
+
+bool arch_uprobe_xol_was_trapped(struct task_struct *t)
+{
+	if (t->thread.trap_no != UPROBE_TRAP_NR)
+		return true;
+
+	return false;
+}
+
+bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+	probe_opcode_t insn;
+	unsigned long addr;
+
+	if (!auprobe->simulate)
+		return false;
+
+	insn = *(probe_opcode_t *)(&auprobe->insn[0]);
+	addr = instruction_pointer(regs);
+
+	if (auprobe->api.handler)
+		auprobe->api.handler(insn, addr, regs);
+
+	return true;
+}
+
+void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+	struct uprobe_task *utask = current->utask;
+
+	/*
+	 * Task has received a fatal signal, so reset back to probbed
+	 * address.
+	 */
+	instruction_pointer_set(regs, utask->vaddr);
+
+	user_disable_single_step(current);
+}
+
+bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx,
+		struct pt_regs *regs)
+{
+	if (ctx == RP_CHECK_CHAIN_CALL)
+		return regs->usp <= ret->stack;
+	else
+		return regs->usp < ret->stack;
+}
+
+unsigned long
+arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
+				  struct pt_regs *regs)
+{
+	unsigned long ra;
+
+	ra = regs->lr;
+
+	regs->lr = trampoline_vaddr;
+
+	return ra;
+}
+
+int arch_uprobe_exception_notify(struct notifier_block *self,
+				 unsigned long val, void *data)
+{
+	return NOTIFY_DONE;
+}
+
+int uprobe_breakpoint_handler(struct pt_regs *regs)
+{
+	if (uprobe_pre_sstep_notifier(regs))
+		return 1;
+
+	return 0;
+}
+
+int uprobe_single_step_handler(struct pt_regs *regs)
+{
+	if (uprobe_post_sstep_notifier(regs))
+		return 1;
+
+	return 0;
+}
diff --git a/arch/csky/kernel/process.c b/arch/csky/kernel/process.c
new file mode 100644
index 000000000..3d0ca22cd
--- /dev/null
+++ b/arch/csky/kernel/process.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/sched/debug.h>
+#include <linux/delay.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+#include <linux/ptrace.h>
+
+#include <asm/elf.h>
+#include <abi/reg_ops.h>
+
+struct cpuinfo_csky cpu_data[NR_CPUS];
+
+#ifdef CONFIG_STACKPROTECTOR
+#include <linux/stackprotector.h>
+unsigned long __stack_chk_guard __read_mostly;
+EXPORT_SYMBOL(__stack_chk_guard);
+#endif
+
+asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
+
+/*
+ * Some archs flush debug and FPU info here
+ */
+void flush_thread(void){}
+
+int copy_thread(unsigned long clone_flags,
+		unsigned long usp,
+		unsigned long kthread_arg,
+		struct task_struct *p,
+		unsigned long tls)
+{
+	struct switch_stack *childstack;
+	struct pt_regs *childregs = task_pt_regs(p);
+
+#ifdef CONFIG_CPU_HAS_FPU
+	save_to_user_fp(&p->thread.user_fp);
+#endif
+
+	childstack = ((struct switch_stack *) childregs) - 1;
+	memset(childstack, 0, sizeof(struct switch_stack));
+
+	/* setup thread.sp for switch_to !!! */
+	p->thread.sp = (unsigned long)childstack;
+
+	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
+		memset(childregs, 0, sizeof(struct pt_regs));
+		childstack->r15 = (unsigned long) ret_from_kernel_thread;
+		childstack->r10 = kthread_arg;
+		childstack->r9 = usp;
+		childregs->sr = mfcr("psr");
+	} else {
+		*childregs = *(current_pt_regs());
+		if (usp)
+			childregs->usp = usp;
+		if (clone_flags & CLONE_SETTLS)
+			task_thread_info(p)->tp_value = childregs->tls
+						      = tls;
+
+		childregs->a0 = 0;
+		childstack->r15 = (unsigned long) ret_from_fork;
+	}
+
+	return 0;
+}
+
+/* Fill in the fpu structure for a core dump.  */
+int dump_fpu(struct pt_regs *regs, struct user_fp *fpu)
+{
+	memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
+	return 1;
+}
+EXPORT_SYMBOL(dump_fpu);
+
+int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
+{
+	struct pt_regs *regs = task_pt_regs(tsk);
+
+	/* NOTE: usp is error value. */
+	ELF_CORE_COPY_REGS((*pr_regs), regs)
+
+	return 1;
+}
+
+#ifndef CONFIG_CPU_PM_NONE
+void arch_cpu_idle(void)
+{
+#ifdef CONFIG_CPU_PM_WAIT
+	asm volatile("wait\n");
+#endif
+
+#ifdef CONFIG_CPU_PM_DOZE
+	asm volatile("doze\n");
+#endif
+
+#ifdef CONFIG_CPU_PM_STOP
+	asm volatile("stop\n");
+#endif
+	raw_local_irq_enable();
+}
+#endif
diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c
new file mode 100644
index 000000000..ac07695bc
--- /dev/null
+++ b/arch/csky/kernel/ptrace.c
@@ -0,0 +1,400 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/audit.h>
+#include <linux/elf.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/ptrace.h>
+#include <linux/regset.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/signal.h>
+#include <linux/smp.h>
+#include <linux/tracehook.h>
+#include <linux/uaccess.h>
+#include <linux/user.h>
+
+#include <asm/thread_info.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+#include <asm/asm-offsets.h>
+
+#include <abi/regdef.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
+/* sets the trace bits. */
+#define TRACE_MODE_SI      (1 << 14)
+#define TRACE_MODE_RUN     0
+#define TRACE_MODE_MASK    ~(0x3 << 14)
+
+/*
+ * Make sure the single step bit is not set.
+ */
+static void singlestep_disable(struct task_struct *tsk)
+{
+	struct pt_regs *regs;
+
+	regs = task_pt_regs(tsk);
+	regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_RUN;
+
+	/* Enable irq */
+	regs->sr |= BIT(6);
+}
+
+static void singlestep_enable(struct task_struct *tsk)
+{
+	struct pt_regs *regs;
+
+	regs = task_pt_regs(tsk);
+	regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_SI;
+
+	/* Disable irq */
+	regs->sr &= ~BIT(6);
+}
+
+/*
+ * Make sure the single step bit is set.
+ */
+void user_enable_single_step(struct task_struct *child)
+{
+	singlestep_enable(child);
+}
+
+void user_disable_single_step(struct task_struct *child)
+{
+	singlestep_disable(child);
+}
+
+enum csky_regset {
+	REGSET_GPR,
+	REGSET_FPR,
+};
+
+static int gpr_get(struct task_struct *target,
+		   const struct user_regset *regset,
+		   struct membuf to)
+{
+	struct pt_regs *regs = task_pt_regs(target);
+
+	/* Abiv1 regs->tls is fake and we need sync here. */
+	regs->tls = task_thread_info(target)->tp_value;
+
+	return membuf_write(&to, regs, sizeof(*regs));
+}
+
+static int gpr_set(struct task_struct *target,
+		    const struct user_regset *regset,
+		    unsigned int pos, unsigned int count,
+		    const void *kbuf, const void __user *ubuf)
+{
+	int ret;
+	struct pt_regs regs;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
+	if (ret)
+		return ret;
+
+	/* BIT(0) of regs.sr is Condition Code/Carry bit */
+	regs.sr = (regs.sr & BIT(0)) | (task_pt_regs(target)->sr & ~BIT(0));
+#ifdef CONFIG_CPU_HAS_HILO
+	regs.dcsr = task_pt_regs(target)->dcsr;
+#endif
+	task_thread_info(target)->tp_value = regs.tls;
+
+	*task_pt_regs(target) = regs;
+
+	return 0;
+}
+
+static int fpr_get(struct task_struct *target,
+		   const struct user_regset *regset,
+		   struct membuf to)
+{
+	struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
+
+#if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
+	int i;
+	struct user_fp tmp = *regs;
+
+	for (i = 0; i < 16; i++) {
+		tmp.vr[i*4] = regs->vr[i*2];
+		tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
+	}
+
+	for (i = 0; i < 32; i++)
+		tmp.vr[64 + i] = regs->vr[32 + i];
+
+	return membuf_write(&to, &tmp, sizeof(tmp));
+#else
+	return membuf_write(&to, regs, sizeof(*regs));
+#endif
+}
+
+static int fpr_set(struct task_struct *target,
+		   const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   const void *kbuf, const void __user *ubuf)
+{
+	int ret;
+	struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
+
+#if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
+	int i;
+	struct user_fp tmp;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
+
+	*regs = tmp;
+
+	for (i = 0; i < 16; i++) {
+		regs->vr[i*2] = tmp.vr[i*4];
+		regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
+	}
+
+	for (i = 0; i < 32; i++)
+		regs->vr[32 + i] = tmp.vr[64 + i];
+#else
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
+#endif
+
+	return ret;
+}
+
+static const struct user_regset csky_regsets[] = {
+	[REGSET_GPR] = {
+		.core_note_type = NT_PRSTATUS,
+		.n = sizeof(struct pt_regs) / sizeof(u32),
+		.size = sizeof(u32),
+		.align = sizeof(u32),
+		.regset_get = gpr_get,
+		.set = gpr_set,
+	},
+	[REGSET_FPR] = {
+		.core_note_type = NT_PRFPREG,
+		.n = sizeof(struct user_fp) / sizeof(u32),
+		.size = sizeof(u32),
+		.align = sizeof(u32),
+		.regset_get = fpr_get,
+		.set = fpr_set,
+	},
+};
+
+static const struct user_regset_view user_csky_view = {
+	.name = "csky",
+	.e_machine = ELF_ARCH,
+	.regsets = csky_regsets,
+	.n = ARRAY_SIZE(csky_regsets),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &user_csky_view;
+}
+
+struct pt_regs_offset {
+	const char *name;
+	int offset;
+};
+
+#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
+#define REG_OFFSET_END {.name = NULL, .offset = 0}
+
+static const struct pt_regs_offset regoffset_table[] = {
+	REG_OFFSET_NAME(tls),
+	REG_OFFSET_NAME(lr),
+	REG_OFFSET_NAME(pc),
+	REG_OFFSET_NAME(sr),
+	REG_OFFSET_NAME(usp),
+	REG_OFFSET_NAME(orig_a0),
+	REG_OFFSET_NAME(a0),
+	REG_OFFSET_NAME(a1),
+	REG_OFFSET_NAME(a2),
+	REG_OFFSET_NAME(a3),
+	REG_OFFSET_NAME(regs[0]),
+	REG_OFFSET_NAME(regs[1]),
+	REG_OFFSET_NAME(regs[2]),
+	REG_OFFSET_NAME(regs[3]),
+	REG_OFFSET_NAME(regs[4]),
+	REG_OFFSET_NAME(regs[5]),
+	REG_OFFSET_NAME(regs[6]),
+	REG_OFFSET_NAME(regs[7]),
+	REG_OFFSET_NAME(regs[8]),
+	REG_OFFSET_NAME(regs[9]),
+#if defined(__CSKYABIV2__)
+	REG_OFFSET_NAME(exregs[0]),
+	REG_OFFSET_NAME(exregs[1]),
+	REG_OFFSET_NAME(exregs[2]),
+	REG_OFFSET_NAME(exregs[3]),
+	REG_OFFSET_NAME(exregs[4]),
+	REG_OFFSET_NAME(exregs[5]),
+	REG_OFFSET_NAME(exregs[6]),
+	REG_OFFSET_NAME(exregs[7]),
+	REG_OFFSET_NAME(exregs[8]),
+	REG_OFFSET_NAME(exregs[9]),
+	REG_OFFSET_NAME(exregs[10]),
+	REG_OFFSET_NAME(exregs[11]),
+	REG_OFFSET_NAME(exregs[12]),
+	REG_OFFSET_NAME(exregs[13]),
+	REG_OFFSET_NAME(exregs[14]),
+	REG_OFFSET_NAME(rhi),
+	REG_OFFSET_NAME(rlo),
+	REG_OFFSET_NAME(dcsr),
+#endif
+	REG_OFFSET_END,
+};
+
+/**
+ * regs_query_register_offset() - query register offset from its name
+ * @name:	the name of a register
+ *
+ * regs_query_register_offset() returns the offset of a register in struct
+ * pt_regs from its name. If the name is invalid, this returns -EINVAL;
+ */
+int regs_query_register_offset(const char *name)
+{
+	const struct pt_regs_offset *roff;
+
+	for (roff = regoffset_table; roff->name != NULL; roff++)
+		if (!strcmp(roff->name, name))
+			return roff->offset;
+	return -EINVAL;
+}
+
+/**
+ * regs_within_kernel_stack() - check the address in the stack
+ * @regs:      pt_regs which contains kernel stack pointer.
+ * @addr:      address which is checked.
+ *
+ * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
+ * If @addr is within the kernel stack, it returns true. If not, returns false.
+ */
+static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
+{
+	return (addr & ~(THREAD_SIZE - 1))  ==
+		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
+}
+
+/**
+ * regs_get_kernel_stack_nth() - get Nth entry of the stack
+ * @regs:	pt_regs which contains kernel stack pointer.
+ * @n:		stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
+ * is specified by @regs. If the @n th entry is NOT in the kernel stack,
+ * this returns 0.
+ */
+unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+
+	addr += n;
+	if (regs_within_kernel_stack(regs, (unsigned long)addr))
+		return *addr;
+	else
+		return 0;
+}
+
+void ptrace_disable(struct task_struct *child)
+{
+	singlestep_disable(child);
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+		 unsigned long addr, unsigned long data)
+{
+	long ret = -EIO;
+
+	switch (request) {
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+
+	return ret;
+}
+
+asmlinkage int syscall_trace_enter(struct pt_regs *regs)
+{
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		if (tracehook_report_syscall_entry(regs))
+			return -1;
+
+	if (secure_computing() == -1)
+		return -1;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_enter(regs, syscall_get_nr(current, regs));
+
+	audit_syscall_entry(regs_syscallid(regs), regs->a0, regs->a1, regs->a2, regs->a3);
+	return 0;
+}
+
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
+{
+	audit_syscall_exit(regs);
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(regs, 0);
+
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_exit(regs, syscall_get_return_value(current, regs));
+}
+
+void show_regs(struct pt_regs *fp)
+{
+	pr_info("\nCURRENT PROCESS:\n\n");
+	pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
+
+	if (current->mm) {
+		pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
+		       (int) current->mm->start_code,
+		       (int) current->mm->end_code,
+		       (int) current->mm->start_data,
+		       (int) current->mm->end_data,
+		       (int) current->mm->end_data,
+		       (int) current->mm->brk);
+		pr_info("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
+		       (int) current->mm->start_stack,
+		       (int) (((unsigned long) current) + 2 * PAGE_SIZE));
+	}
+
+	pr_info("PC: 0x%08lx (%pS)\n", (long)fp->pc, (void *)fp->pc);
+	pr_info("LR: 0x%08lx (%pS)\n", (long)fp->lr, (void *)fp->lr);
+	pr_info("SP: 0x%08lx\n", (long)fp);
+	pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
+	pr_info("PSR: 0x%08lx\n", (long)fp->sr);
+
+	pr_info(" a0: 0x%08lx   a1: 0x%08lx   a2: 0x%08lx   a3: 0x%08lx\n",
+		fp->a0, fp->a1, fp->a2, fp->a3);
+#if defined(__CSKYABIV2__)
+	pr_info(" r4: 0x%08lx   r5: 0x%08lx   r6: 0x%08lx   r7: 0x%08lx\n",
+		fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
+	pr_info(" r8: 0x%08lx   r9: 0x%08lx  r10: 0x%08lx  r11: 0x%08lx\n",
+		fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
+	pr_info("r12: 0x%08lx  r13: 0x%08lx  r15: 0x%08lx\n",
+		fp->regs[8], fp->regs[9], fp->lr);
+	pr_info("r16: 0x%08lx  r17: 0x%08lx  r18: 0x%08lx  r19: 0x%08lx\n",
+		fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
+	pr_info("r20: 0x%08lx  r21: 0x%08lx  r22: 0x%08lx  r23: 0x%08lx\n",
+		fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
+	pr_info("r24: 0x%08lx  r25: 0x%08lx  r26: 0x%08lx  r27: 0x%08lx\n",
+		fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
+	pr_info("r28: 0x%08lx  r29: 0x%08lx  r30: 0x%08lx  tls: 0x%08lx\n",
+		fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
+	pr_info(" hi: 0x%08lx   lo: 0x%08lx\n",
+		fp->rhi, fp->rlo);
+#else
+	pr_info(" r6: 0x%08lx   r7: 0x%08lx   r8: 0x%08lx   r9: 0x%08lx\n",
+		fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
+	pr_info("r10: 0x%08lx  r11: 0x%08lx  r12: 0x%08lx  r13: 0x%08lx\n",
+		fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
+	pr_info("r14: 0x%08lx   r1: 0x%08lx\n",
+		fp->regs[8], fp->regs[9]);
+#endif
+
+	return;
+}
diff --git a/arch/csky/kernel/setup.c b/arch/csky/kernel/setup.c
new file mode 100644
index 000000000..e4cab1605
--- /dev/null
+++ b/arch/csky/kernel/setup.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/console.h>
+#include <linux/memblock.h>
+#include <linux/initrd.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/start_kernel.h>
+#include <linux/dma-map-ops.h>
+#include <linux/screen_info.h>
+#include <asm/sections.h>
+#include <asm/mmu_context.h>
+#include <asm/pgalloc.h>
+
+#ifdef CONFIG_DUMMY_CONSOLE
+struct screen_info screen_info = {
+	.orig_video_lines	= 30,
+	.orig_video_cols	= 80,
+	.orig_video_mode	= 0,
+	.orig_video_ega_bx	= 0,
+	.orig_video_isVGA	= 1,
+	.orig_video_points	= 8
+};
+#endif
+
+static void __init csky_memblock_init(void)
+{
+	unsigned long lowmem_size = PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
+	unsigned long sseg_size = PFN_DOWN(SSEG_SIZE - PHYS_OFFSET_OFFSET);
+	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
+	signed long size;
+
+	memblock_reserve(__pa(_stext), _end - _stext);
+
+	early_init_fdt_reserve_self();
+	early_init_fdt_scan_reserved_mem();
+
+	memblock_dump_all();
+
+	min_low_pfn = PFN_UP(memblock_start_of_DRAM());
+	max_low_pfn = max_pfn = PFN_DOWN(memblock_end_of_DRAM());
+
+	size = max_pfn - min_low_pfn;
+
+	if (size >= lowmem_size) {
+		max_low_pfn = min_low_pfn + lowmem_size;
+		write_mmu_msa1(read_mmu_msa0() + SSEG_SIZE);
+	} else if (size > sseg_size) {
+		max_low_pfn = min_low_pfn + sseg_size;
+	}
+
+	max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
+
+#ifdef CONFIG_HIGHMEM
+	max_zone_pfn[ZONE_HIGHMEM] = max_pfn;
+
+	highstart_pfn = max_low_pfn;
+	highend_pfn   = max_pfn;
+#endif
+	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
+
+	dma_contiguous_reserve(0);
+
+	free_area_init(max_zone_pfn);
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+	*cmdline_p = boot_command_line;
+
+	console_verbose();
+
+	pr_info("Phys. mem: %ldMB\n",
+		(unsigned long) memblock_phys_mem_size()/1024/1024);
+
+	init_mm.start_code = (unsigned long) _stext;
+	init_mm.end_code = (unsigned long) _etext;
+	init_mm.end_data = (unsigned long) _edata;
+	init_mm.brk = (unsigned long) _end;
+
+	parse_early_param();
+
+	csky_memblock_init();
+
+	unflatten_and_copy_device_tree();
+
+#ifdef CONFIG_SMP
+	setup_smp();
+#endif
+
+	sparse_init();
+
+	fixaddr_init();
+
+#ifdef CONFIG_HIGHMEM
+	kmap_init();
+#endif
+}
+
+unsigned long va_pa_offset;
+EXPORT_SYMBOL(va_pa_offset);
+
+asmlinkage __visible void __init csky_start(unsigned int unused,
+					    void *dtb_start)
+{
+	/* Clean up bss section */
+	memset(__bss_start, 0, __bss_stop - __bss_start);
+
+	va_pa_offset = read_mmu_msa0() & ~(SSEG_SIZE - 1);
+
+	pre_trap_init();
+	pre_mmu_init();
+
+	if (dtb_start == NULL)
+		early_init_dt_scan(__dtb_start);
+	else
+		early_init_dt_scan(dtb_start);
+
+	start_kernel();
+
+	asm volatile("br .\n");
+}
diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c
new file mode 100644
index 000000000..f7c1677e5
--- /dev/null
+++ b/arch/csky/kernel/signal.c
@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/signal.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/tracehook.h>
+
+#include <asm/traps.h>
+#include <asm/ucontext.h>
+#include <asm/vdso.h>
+
+#include <abi/regdef.h>
+
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+static int restore_fpu_state(struct sigcontext __user *sc)
+{
+	int err = 0;
+	struct user_fp user_fp;
+
+	err = __copy_from_user(&user_fp, &sc->sc_user_fp, sizeof(user_fp));
+
+	restore_from_user_fp(&user_fp);
+
+	return err;
+}
+
+static int save_fpu_state(struct sigcontext __user *sc)
+{
+	struct user_fp user_fp;
+
+	save_to_user_fp(&user_fp);
+
+	return __copy_to_user(&sc->sc_user_fp, &user_fp, sizeof(user_fp));
+}
+#else
+#define restore_fpu_state(sigcontext)	(0)
+#define save_fpu_state(sigcontext)	(0)
+#endif
+
+struct rt_sigframe {
+	/*
+	 * pad[3] is compatible with the same struct defined in
+	 * gcc/libgcc/config/csky/linux-unwind.h
+	 */
+	int pad[3];
+	struct siginfo info;
+	struct ucontext uc;
+};
+
+static long restore_sigcontext(struct pt_regs *regs,
+	struct sigcontext __user *sc)
+{
+	int err = 0;
+	unsigned long sr = regs->sr;
+
+	/* sc_pt_regs is structured the same as the start of pt_regs */
+	err |= __copy_from_user(regs, &sc->sc_pt_regs, sizeof(struct pt_regs));
+
+	/* BIT(0) of regs->sr is Condition Code/Carry bit */
+	regs->sr = (sr & ~1) | (regs->sr & 1);
+
+	/* Restore the floating-point state. */
+	err |= restore_fpu_state(sc);
+
+	return err;
+}
+
+SYSCALL_DEFINE0(rt_sigreturn)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct rt_sigframe __user *frame;
+	sigset_t set;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	frame = (struct rt_sigframe __user *)regs->usp;
+
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->a0;
+
+badframe:
+	force_sig(SIGSEGV);
+	return 0;
+}
+
+static int setup_sigcontext(struct rt_sigframe __user *frame,
+	struct pt_regs *regs)
+{
+	struct sigcontext __user *sc = &frame->uc.uc_mcontext;
+	int err = 0;
+
+	err |= __copy_to_user(&sc->sc_pt_regs, regs, sizeof(struct pt_regs));
+	err |= save_fpu_state(sc);
+
+	return err;
+}
+
+static inline void __user *get_sigframe(struct ksignal *ksig,
+	struct pt_regs *regs, size_t framesize)
+{
+	unsigned long sp;
+	/* Default to using normal stack */
+	sp = regs->usp;
+
+	/*
+	 * If we are on the alternate signal stack and would overflow it, don't.
+	 * Return an always-bogus address instead so we will die with SIGSEGV.
+	 */
+	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
+		return (void __user __force *)(-1UL);
+
+	/* This is the X/Open sanctioned signal stack switching. */
+	sp = sigsp(sp, ksig) - framesize;
+
+	/* Align the stack frame. */
+	sp &= -8UL;
+
+	return (void __user *)sp;
+}
+
+static int
+setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+	int err = 0;
+	struct csky_vdso *vdso = current->mm->context.vdso;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame));
+	if (!access_ok(frame, sizeof(*frame)))
+		return -EFAULT;
+
+	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+
+	/* Create the ucontext. */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(NULL, &frame->uc.uc_link);
+	err |= __save_altstack(&frame->uc.uc_stack, regs->usp);
+	err |= setup_sigcontext(frame, regs);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+	if (err)
+		return -EFAULT;
+
+	/* Set up to return from userspace. */
+	regs->lr = (unsigned long)(vdso->rt_signal_retcode);
+
+	/*
+	 * Set up registers for signal handler.
+	 * Registers that we don't modify keep the value they had from
+	 * user-space at the time we took the signal.
+	 * We always pass siginfo and mcontext, regardless of SA_SIGINFO,
+	 * since some things rely on this (e.g. glibc's debug/segfault.c).
+	 */
+	regs->pc  = (unsigned long)ksig->ka.sa.sa_handler;
+	regs->usp = (unsigned long)frame;
+	regs->a0  = ksig->sig;				/* a0: signal number */
+	regs->a1  = (unsigned long)(&(frame->info));	/* a1: siginfo pointer */
+	regs->a2  = (unsigned long)(&(frame->uc));	/* a2: ucontext pointer */
+
+	return 0;
+}
+
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	sigset_t *oldset = sigmask_to_save();
+	int ret;
+
+	rseq_signal_deliver(ksig, regs);
+
+	/* Are we from a system call? */
+	if (in_syscall(regs)) {
+		/* Avoid additional syscall restarting via ret_from_exception */
+		forget_syscall(regs);
+
+		/* If so, check system call restarting.. */
+		switch (regs->a0) {
+		case -ERESTART_RESTARTBLOCK:
+		case -ERESTARTNOHAND:
+			regs->a0 = -EINTR;
+			break;
+
+		case -ERESTARTSYS:
+			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+				regs->a0 = -EINTR;
+				break;
+			}
+			fallthrough;
+		case -ERESTARTNOINTR:
+			regs->a0 = regs->orig_a0;
+			regs->pc -= TRAP0_SIZE;
+			break;
+		}
+	}
+
+	/* Set up the stack frame */
+	ret = setup_rt_frame(ksig, oldset, regs);
+
+	signal_setup_done(ret, ksig, 0);
+}
+
+static void do_signal(struct pt_regs *regs)
+{
+	struct ksignal ksig;
+
+	if (get_signal(&ksig)) {
+		/* Actually deliver the signal */
+		handle_signal(&ksig, regs);
+		return;
+	}
+
+	/* Did we come from a system call? */
+	if (in_syscall(regs)) {
+		/* Avoid additional syscall restarting via ret_from_exception */
+		forget_syscall(regs);
+
+		/* Restart the system call - no handlers present */
+		switch (regs->a0) {
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+			regs->a0 = regs->orig_a0;
+			regs->pc -= TRAP0_SIZE;
+			break;
+		case -ERESTART_RESTARTBLOCK:
+			regs->a0 = regs->orig_a0;
+			regs_syscallid(regs) = __NR_restart_syscall;
+			regs->pc -= TRAP0_SIZE;
+			break;
+		}
+	}
+
+	/*
+	 * If there is no signal to deliver, we just put the saved
+	 * sigmask back.
+	 */
+	restore_saved_sigmask();
+}
+
+/*
+ * notification of userspace execution resumption
+ * - triggered by the _TIF_WORK_MASK flags
+ */
+asmlinkage void do_notify_resume(struct pt_regs *regs,
+	unsigned long thread_info_flags)
+{
+	if (thread_info_flags & _TIF_UPROBE)
+		uprobe_notify_resume(regs);
+
+	/* Handle pending signal delivery */
+	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
+		do_signal(regs);
+
+	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+		tracehook_notify_resume(regs);
+		rseq_handle_notify_resume(NULL, regs);
+	}
+}
diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c
new file mode 100644
index 000000000..1a8d7eaf1
--- /dev/null
+++ b/arch/csky/kernel/smp.c
@@ -0,0 +1,329 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
+#include <linux/percpu.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/irq_work.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/seq_file.h>
+#include <linux/sched/task_stack.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/hotplug.h>
+#include <asm/irq.h>
+#include <asm/traps.h>
+#include <asm/sections.h>
+#include <asm/mmu_context.h>
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+#endif
+
+enum ipi_message_type {
+	IPI_EMPTY,
+	IPI_RESCHEDULE,
+	IPI_CALL_FUNC,
+	IPI_IRQ_WORK,
+	IPI_MAX
+};
+
+struct ipi_data_struct {
+	unsigned long bits ____cacheline_aligned;
+	unsigned long stats[IPI_MAX] ____cacheline_aligned;
+};
+static DEFINE_PER_CPU(struct ipi_data_struct, ipi_data);
+
+static irqreturn_t handle_ipi(int irq, void *dev)
+{
+	unsigned long *stats = this_cpu_ptr(&ipi_data)->stats;
+
+	while (true) {
+		unsigned long ops;
+
+		ops = xchg(&this_cpu_ptr(&ipi_data)->bits, 0);
+		if (ops == 0)
+			return IRQ_HANDLED;
+
+		if (ops & (1 << IPI_RESCHEDULE)) {
+			stats[IPI_RESCHEDULE]++;
+			scheduler_ipi();
+		}
+
+		if (ops & (1 << IPI_CALL_FUNC)) {
+			stats[IPI_CALL_FUNC]++;
+			generic_smp_call_function_interrupt();
+		}
+
+		if (ops & (1 << IPI_IRQ_WORK)) {
+			stats[IPI_IRQ_WORK]++;
+			irq_work_run();
+		}
+
+		BUG_ON((ops >> IPI_MAX) != 0);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void (*send_arch_ipi)(const struct cpumask *mask);
+
+static int ipi_irq;
+void __init set_send_ipi(void (*func)(const struct cpumask *mask), int irq)
+{
+	if (send_arch_ipi)
+		return;
+
+	send_arch_ipi = func;
+	ipi_irq = irq;
+}
+
+static void
+send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
+{
+	int i;
+
+	for_each_cpu(i, to_whom)
+		set_bit(operation, &per_cpu_ptr(&ipi_data, i)->bits);
+
+	smp_mb();
+	send_arch_ipi(to_whom);
+}
+
+static const char * const ipi_names[] = {
+	[IPI_EMPTY]		= "Empty interrupts",
+	[IPI_RESCHEDULE]	= "Rescheduling interrupts",
+	[IPI_CALL_FUNC]		= "Function call interrupts",
+	[IPI_IRQ_WORK]		= "Irq work interrupts",
+};
+
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+	unsigned int cpu, i;
+
+	for (i = 0; i < IPI_MAX; i++) {
+		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
+			   prec >= 4 ? " " : "");
+		for_each_online_cpu(cpu)
+			seq_printf(p, "%10lu ",
+				per_cpu_ptr(&ipi_data, cpu)->stats[i]);
+		seq_printf(p, " %s\n", ipi_names[i]);
+	}
+
+	return 0;
+}
+
+void arch_send_call_function_ipi_mask(struct cpumask *mask)
+{
+	send_ipi_message(mask, IPI_CALL_FUNC);
+}
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+	send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
+}
+
+static void ipi_stop(void *unused)
+{
+	while (1);
+}
+
+void smp_send_stop(void)
+{
+	on_each_cpu(ipi_stop, NULL, 1);
+}
+
+void smp_send_reschedule(int cpu)
+{
+	send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
+}
+
+#ifdef CONFIG_IRQ_WORK
+void arch_irq_work_raise(void)
+{
+	send_ipi_message(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
+}
+#endif
+
+void __init smp_prepare_boot_cpu(void)
+{
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+}
+
+static int ipi_dummy_dev;
+
+void __init setup_smp_ipi(void)
+{
+	int rc;
+
+	if (ipi_irq == 0)
+		return;
+
+	rc = request_percpu_irq(ipi_irq, handle_ipi, "IPI Interrupt",
+				&ipi_dummy_dev);
+	if (rc)
+		panic("%s IRQ request failed\n", __func__);
+
+	enable_percpu_irq(ipi_irq, 0);
+}
+
+void __init setup_smp(void)
+{
+	struct device_node *node = NULL;
+	int cpu;
+
+	for_each_of_cpu_node(node) {
+		if (!of_device_is_available(node))
+			continue;
+
+		if (of_property_read_u32(node, "reg", &cpu))
+			continue;
+
+		if (cpu >= NR_CPUS)
+			continue;
+
+		set_cpu_possible(cpu, true);
+		set_cpu_present(cpu, true);
+	}
+}
+
+extern void _start_smp_secondary(void);
+
+volatile unsigned int secondary_hint;
+volatile unsigned int secondary_hint2;
+volatile unsigned int secondary_ccr;
+volatile unsigned int secondary_stack;
+
+unsigned long secondary_msa1;
+
+int __cpu_up(unsigned int cpu, struct task_struct *tidle)
+{
+	unsigned long mask = 1 << cpu;
+
+	secondary_stack =
+		(unsigned int) task_stack_page(tidle) + THREAD_SIZE - 8;
+	secondary_hint = mfcr("cr31");
+	secondary_hint2 = mfcr("cr<21, 1>");
+	secondary_ccr  = mfcr("cr18");
+	secondary_msa1 = read_mmu_msa1();
+
+	/*
+	 * Because other CPUs are in reset status, we must flush data
+	 * from cache to out and secondary CPUs use them in
+	 * csky_start_secondary(void)
+	 */
+	mtcr("cr17", 0x22);
+
+	if (mask & mfcr("cr<29, 0>")) {
+		send_arch_ipi(cpumask_of(cpu));
+	} else {
+		/* Enable cpu in SMP reset ctrl reg */
+		mask |= mfcr("cr<29, 0>");
+		mtcr("cr<29, 0>", mask);
+	}
+
+	/* Wait for the cpu online */
+	while (!cpu_online(cpu));
+
+	secondary_stack = 0;
+
+	return 0;
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+}
+
+int setup_profiling_timer(unsigned int multiplier)
+{
+	return -EINVAL;
+}
+
+void csky_start_secondary(void)
+{
+	struct mm_struct *mm = &init_mm;
+	unsigned int cpu = smp_processor_id();
+
+	mtcr("cr31", secondary_hint);
+	mtcr("cr<21, 1>", secondary_hint2);
+	mtcr("cr18", secondary_ccr);
+
+	mtcr("vbr", vec_base);
+
+	flush_tlb_all();
+	write_mmu_pagemask(0);
+	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
+	TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
+
+#ifdef CONFIG_CPU_HAS_FPU
+	init_fpu();
+#endif
+
+	enable_percpu_irq(ipi_irq, 0);
+
+	mmget(mm);
+	mmgrab(mm);
+	current->active_mm = mm;
+	cpumask_set_cpu(cpu, mm_cpumask(mm));
+
+	notify_cpu_starting(cpu);
+	set_cpu_online(cpu, true);
+
+	pr_info("CPU%u Online: %s...\n", cpu, __func__);
+
+	local_irq_enable();
+	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+int __cpu_disable(void)
+{
+	unsigned int cpu = smp_processor_id();
+
+	set_cpu_online(cpu, false);
+
+	irq_migrate_all_off_this_cpu();
+
+	clear_tasks_mm_cpumask(cpu);
+
+	return 0;
+}
+
+void __cpu_die(unsigned int cpu)
+{
+	if (!cpu_wait_death(cpu, 5)) {
+		pr_crit("CPU%u: shutdown failed\n", cpu);
+		return;
+	}
+	pr_notice("CPU%u: shutdown\n", cpu);
+}
+
+void arch_cpu_idle_dead(void)
+{
+	idle_task_exit();
+
+	cpu_report_death();
+
+	while (!secondary_stack)
+		arch_cpu_idle();
+
+	local_irq_disable();
+
+	asm volatile(
+		"mov	sp, %0\n"
+		"mov	r8, %0\n"
+		"jmpi	csky_start_secondary"
+		:
+		: "r" (secondary_stack));
+}
+#endif
diff --git a/arch/csky/kernel/stacktrace.c b/arch/csky/kernel/stacktrace.c
new file mode 100644
index 000000000..16ae20a0a
--- /dev/null
+++ b/arch/csky/kernel/stacktrace.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/sched/debug.h>
+#include <linux/sched/task_stack.h>
+#include <linux/stacktrace.h>
+#include <linux/ftrace.h>
+#include <linux/ptrace.h>
+
+#ifdef CONFIG_FRAME_POINTER
+
+struct stackframe {
+	unsigned long fp;
+	unsigned long ra;
+};
+
+void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
+			     bool (*fn)(unsigned long, void *), void *arg)
+{
+	unsigned long fp, sp, pc;
+
+	if (regs) {
+		fp = frame_pointer(regs);
+		sp = user_stack_pointer(regs);
+		pc = instruction_pointer(regs);
+	} else if (task == NULL || task == current) {
+		const register unsigned long current_sp __asm__ ("sp");
+		const register unsigned long current_fp __asm__ ("r8");
+		fp = current_fp;
+		sp = current_sp;
+		pc = (unsigned long)walk_stackframe;
+	} else {
+		/* task blocked in __switch_to */
+		fp = thread_saved_fp(task);
+		sp = thread_saved_sp(task);
+		pc = thread_saved_lr(task);
+	}
+
+	for (;;) {
+		unsigned long low, high;
+		struct stackframe *frame;
+
+		if (unlikely(!__kernel_text_address(pc) || fn(pc, arg)))
+			break;
+
+		/* Validate frame pointer */
+		low = sp;
+		high = ALIGN(sp, THREAD_SIZE);
+		if (unlikely(fp < low || fp > high || fp & 0x3))
+			break;
+		/* Unwind stack frame */
+		frame = (struct stackframe *)fp;
+		sp = fp;
+		fp = frame->fp;
+		pc = ftrace_graph_ret_addr(current, NULL, frame->ra,
+					   (unsigned long *)(fp - 8));
+	}
+}
+
+#else /* !CONFIG_FRAME_POINTER */
+
+static void notrace walk_stackframe(struct task_struct *task,
+	struct pt_regs *regs, bool (*fn)(unsigned long, void *), void *arg)
+{
+	unsigned long sp, pc;
+	unsigned long *ksp;
+
+	if (regs) {
+		sp = user_stack_pointer(regs);
+		pc = instruction_pointer(regs);
+	} else if (task == NULL || task == current) {
+		const register unsigned long current_sp __asm__ ("sp");
+		sp = current_sp;
+		pc = (unsigned long)walk_stackframe;
+	} else {
+		/* task blocked in __switch_to */
+		sp = thread_saved_sp(task);
+		pc = thread_saved_lr(task);
+	}
+
+	if (unlikely(sp & 0x3))
+		return;
+
+	ksp = (unsigned long *)sp;
+	while (!kstack_end(ksp)) {
+		if (__kernel_text_address(pc) && unlikely(fn(pc, arg)))
+			break;
+		pc = (*ksp++) - 0x4;
+	}
+}
+#endif /* CONFIG_FRAME_POINTER */
+
+static bool print_trace_address(unsigned long pc, void *arg)
+{
+	print_ip_sym((const char *)arg, pc);
+	return false;
+}
+
+void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
+{
+	pr_cont("Call Trace:\n");
+	walk_stackframe(task, NULL, print_trace_address, (void *)loglvl);
+}
+
+static bool save_wchan(unsigned long pc, void *arg)
+{
+	if (!in_sched_functions(pc)) {
+		unsigned long *p = arg;
+		*p = pc;
+		return true;
+	}
+	return false;
+}
+
+unsigned long get_wchan(struct task_struct *task)
+{
+	unsigned long pc = 0;
+
+	if (likely(task && task != current && task->state != TASK_RUNNING))
+		walk_stackframe(task, NULL, save_wchan, &pc);
+	return pc;
+}
+
+#ifdef CONFIG_STACKTRACE
+static bool __save_trace(unsigned long pc, void *arg, bool nosched)
+{
+	struct stack_trace *trace = arg;
+
+	if (unlikely(nosched && in_sched_functions(pc)))
+		return false;
+	if (unlikely(trace->skip > 0)) {
+		trace->skip--;
+		return false;
+	}
+
+	trace->entries[trace->nr_entries++] = pc;
+	return (trace->nr_entries >= trace->max_entries);
+}
+
+static bool save_trace(unsigned long pc, void *arg)
+{
+	return __save_trace(pc, arg, false);
+}
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+	walk_stackframe(tsk, NULL, save_trace, trace);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+void save_stack_trace(struct stack_trace *trace)
+{
+	save_stack_trace_tsk(NULL, trace);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+#endif /* CONFIG_STACKTRACE */
diff --git a/arch/csky/kernel/syscall.c b/arch/csky/kernel/syscall.c
new file mode 100644
index 000000000..3d30e58a4
--- /dev/null
+++ b/arch/csky/kernel/syscall.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/syscalls.h>
+
+SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
+{
+	struct thread_info *ti = task_thread_info(current);
+	struct pt_regs *reg = current_pt_regs();
+
+	reg->tls = addr;
+	ti->tp_value = addr;
+
+	return 0;
+}
+
+SYSCALL_DEFINE6(mmap2,
+	unsigned long, addr,
+	unsigned long, len,
+	unsigned long, prot,
+	unsigned long, flags,
+	unsigned long, fd,
+	off_t, offset)
+{
+	if (unlikely(offset & (~PAGE_MASK >> 12)))
+		return -EINVAL;
+
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       offset >> (PAGE_SHIFT - 12));
+}
+
+/*
+ * for abiv1 the 64bits args should be even th, So we need mov the advice
+ * forward.
+ */
+SYSCALL_DEFINE4(csky_fadvise64_64,
+	int, fd,
+	int, advice,
+	loff_t, offset,
+	loff_t, len)
+{
+	return ksys_fadvise64_64(fd, offset, len, advice);
+}
diff --git a/arch/csky/kernel/syscall_table.c b/arch/csky/kernel/syscall_table.c
new file mode 100644
index 000000000..a0c238c53
--- /dev/null
+++ b/arch/csky/kernel/syscall_table.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/syscalls.h>
+#include <asm/syscalls.h>
+
+#undef __SYSCALL
+#define __SYSCALL(nr, call)[nr] = (call),
+
+#define sys_fadvise64_64 sys_csky_fadvise64_64
+void * const sys_call_table[__NR_syscalls] __page_aligned_data = {
+	[0 ... __NR_syscalls - 1] = sys_ni_syscall,
+#include <asm/unistd.h>
+};
diff --git a/arch/csky/kernel/time.c b/arch/csky/kernel/time.c
new file mode 100644
index 000000000..52379d866
--- /dev/null
+++ b/arch/csky/kernel/time.c
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/clocksource.h>
+#include <linux/of_clk.h>
+
+void __init time_init(void)
+{
+	of_clk_init(NULL);
+	timer_probe();
+}
diff --git a/arch/csky/kernel/traps.c b/arch/csky/kernel/traps.c
new file mode 100644
index 000000000..15711efa1
--- /dev/null
+++ b/arch/csky/kernel/traps.c
@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/user.h>
+#include <linux/string.h>
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <linux/ptrace.h>
+#include <linux/kallsyms.h>
+#include <linux/rtc.h>
+#include <linux/uaccess.h>
+#include <linux/kprobes.h>
+#include <linux/kdebug.h>
+#include <linux/sched/debug.h>
+
+#include <asm/setup.h>
+#include <asm/traps.h>
+#include <asm/pgalloc.h>
+#include <asm/siginfo.h>
+
+#include <asm/mmu_context.h>
+
+#ifdef CONFIG_CPU_HAS_FPU
+#include <abi/fpu.h>
+#endif
+
+int show_unhandled_signals = 1;
+
+/* Defined in entry.S */
+asmlinkage void csky_trap(void);
+
+asmlinkage void csky_systemcall(void);
+asmlinkage void csky_cmpxchg(void);
+asmlinkage void csky_get_tls(void);
+asmlinkage void csky_irq(void);
+
+asmlinkage void csky_tlbinvalidl(void);
+asmlinkage void csky_tlbinvalids(void);
+asmlinkage void csky_tlbmodified(void);
+
+/* Defined in head.S */
+asmlinkage void _start_smp_secondary(void);
+
+void __init pre_trap_init(void)
+{
+	int i;
+
+	mtcr("vbr", vec_base);
+
+	for (i = 1; i < 128; i++)
+		VEC_INIT(i, csky_trap);
+}
+
+void __init trap_init(void)
+{
+	VEC_INIT(VEC_AUTOVEC, csky_irq);
+
+	/* setup trap0 trap2 trap3 */
+	VEC_INIT(VEC_TRAP0, csky_systemcall);
+	VEC_INIT(VEC_TRAP2, csky_cmpxchg);
+	VEC_INIT(VEC_TRAP3, csky_get_tls);
+
+	/* setup MMU TLB exception */
+	VEC_INIT(VEC_TLBINVALIDL, csky_tlbinvalidl);
+	VEC_INIT(VEC_TLBINVALIDS, csky_tlbinvalids);
+	VEC_INIT(VEC_TLBMODIFIED, csky_tlbmodified);
+
+#ifdef CONFIG_CPU_HAS_FPU
+	init_fpu();
+#endif
+
+#ifdef CONFIG_SMP
+	mtcr("cr<28, 0>", virt_to_phys(vec_base));
+
+	VEC_INIT(VEC_RESET, (void *)virt_to_phys(_start_smp_secondary));
+#endif
+}
+
+static DEFINE_SPINLOCK(die_lock);
+
+void die(struct pt_regs *regs, const char *str)
+{
+	static int die_counter;
+	int ret;
+
+	oops_enter();
+
+	spin_lock_irq(&die_lock);
+	console_verbose();
+	bust_spinlocks(1);
+
+	pr_emerg("%s [#%d]\n", str, ++die_counter);
+	print_modules();
+	show_regs(regs);
+	show_stack(current, (unsigned long *)regs->regs[4], KERN_INFO);
+
+	ret = notify_die(DIE_OOPS, str, regs, 0, trap_no(regs), SIGSEGV);
+
+	bust_spinlocks(0);
+	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
+	spin_unlock_irq(&die_lock);
+	oops_exit();
+
+	if (in_interrupt())
+		panic("Fatal exception in interrupt");
+	if (panic_on_oops)
+		panic("Fatal exception");
+	if (ret != NOTIFY_STOP)
+		make_task_dead(SIGSEGV);
+}
+
+void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
+{
+	struct task_struct *tsk = current;
+
+	if (show_unhandled_signals && unhandled_signal(tsk, signo)
+	    && printk_ratelimit()) {
+		pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x%08lx",
+			tsk->comm, task_pid_nr(tsk), signo, code, addr);
+		print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
+		pr_cont("\n");
+		show_regs(regs);
+	}
+
+	force_sig_fault(signo, code, (void __user *)addr);
+}
+
+static void do_trap_error(struct pt_regs *regs, int signo, int code,
+	unsigned long addr, const char *str)
+{
+	current->thread.trap_no = trap_no(regs);
+
+	if (user_mode(regs)) {
+		do_trap(regs, signo, code, addr);
+	} else {
+		if (!fixup_exception(regs))
+			die(regs, str);
+	}
+}
+
+#define DO_ERROR_INFO(name, signo, code, str)				\
+asmlinkage __visible void name(struct pt_regs *regs)			\
+{									\
+	do_trap_error(regs, signo, code, regs->pc, "Oops - " str);	\
+}
+
+DO_ERROR_INFO(do_trap_unknown,
+	SIGILL, ILL_ILLTRP, "unknown exception");
+DO_ERROR_INFO(do_trap_zdiv,
+	SIGFPE, FPE_INTDIV, "error zero div exception");
+DO_ERROR_INFO(do_trap_buserr,
+	SIGSEGV, ILL_ILLADR, "error bus error exception");
+
+asmlinkage void do_trap_misaligned(struct pt_regs *regs)
+{
+#ifdef CONFIG_CPU_NEED_SOFTALIGN
+	csky_alignment(regs);
+#else
+	current->thread.trap_no = trap_no(regs);
+	do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->pc,
+		      "Oops - load/store address misaligned");
+#endif
+}
+
+asmlinkage void do_trap_bkpt(struct pt_regs *regs)
+{
+#ifdef CONFIG_KPROBES
+	if (kprobe_single_step_handler(regs))
+		return;
+#endif
+#ifdef CONFIG_UPROBES
+	if (uprobe_single_step_handler(regs))
+		return;
+#endif
+	if (user_mode(regs)) {
+		send_sig(SIGTRAP, current, 0);
+		return;
+	}
+
+	do_trap_error(regs, SIGILL, ILL_ILLTRP, regs->pc,
+		      "Oops - illegal trap exception");
+}
+
+asmlinkage void do_trap_illinsn(struct pt_regs *regs)
+{
+	current->thread.trap_no = trap_no(regs);
+
+#ifdef CONFIG_KPROBES
+	if (kprobe_breakpoint_handler(regs))
+		return;
+#endif
+#ifdef CONFIG_UPROBES
+	if (uprobe_breakpoint_handler(regs))
+		return;
+#endif
+#ifndef CONFIG_CPU_NO_USER_BKPT
+	if (*(uint16_t *)instruction_pointer(regs) != USR_BKPT) {
+		send_sig(SIGTRAP, current, 0);
+		return;
+	}
+#endif
+
+	do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc,
+		      "Oops - illegal instruction exception");
+}
+
+asmlinkage void do_trap_fpe(struct pt_regs *regs)
+{
+#ifdef CONFIG_CPU_HAS_FPU
+	return fpu_fpe(regs);
+#else
+	do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->pc,
+		      "Oops - fpu instruction exception");
+#endif
+}
+
+asmlinkage void do_trap_priv(struct pt_regs *regs)
+{
+#ifdef CONFIG_CPU_HAS_FPU
+	if (user_mode(regs) && fpu_libc_helper(regs))
+		return;
+#endif
+	do_trap_error(regs, SIGILL, ILL_PRVOPC, regs->pc,
+		      "Oops - illegal privileged exception");
+}
+
+asmlinkage void trap_c(struct pt_regs *regs)
+{
+	switch (trap_no(regs)) {
+	case VEC_ZERODIV:
+		do_trap_zdiv(regs);
+		break;
+	case VEC_TRACE:
+		do_trap_bkpt(regs);
+		break;
+	case VEC_ILLEGAL:
+		do_trap_illinsn(regs);
+		break;
+	case VEC_TRAP1:
+	case VEC_BREAKPOINT:
+		do_trap_bkpt(regs);
+		break;
+	case VEC_ACCESS:
+		do_trap_buserr(regs);
+		break;
+	case VEC_ALIGN:
+		do_trap_misaligned(regs);
+		break;
+	case VEC_FPE:
+		do_trap_fpe(regs);
+		break;
+	case VEC_PRIV:
+		do_trap_priv(regs);
+		break;
+	default:
+		do_trap_unknown(regs);
+		break;
+	}
+}
diff --git a/arch/csky/kernel/vdso.c b/arch/csky/kernel/vdso.c
new file mode 100644
index 000000000..abc3dbc65
--- /dev/null
+++ b/arch/csky/kernel/vdso.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/binfmts.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/unistd.h>
+#include <linux/uaccess.h>
+
+#include <asm/vdso.h>
+#include <asm/cacheflush.h>
+
+static struct page *vdso_page;
+
+static int __init init_vdso(void)
+{
+	struct csky_vdso *vdso;
+	int err = 0;
+
+	vdso_page = alloc_page(GFP_KERNEL);
+	if (!vdso_page)
+		panic("Cannot allocate vdso");
+
+	vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
+	if (!vdso)
+		panic("Cannot map vdso");
+
+	clear_page(vdso);
+
+	err = setup_vdso_page(vdso->rt_signal_retcode);
+	if (err)
+		panic("Cannot set signal return code, err: %x.", err);
+
+	dcache_wb_range((unsigned long)vdso, (unsigned long)vdso + 16);
+
+	vunmap(vdso);
+
+	return 0;
+}
+subsys_initcall(init_vdso);
+
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+{
+	int ret;
+	unsigned long addr;
+	struct mm_struct *mm = current->mm;
+
+	mmap_write_lock(mm);
+
+	addr = get_unmapped_area(NULL, STACK_TOP, PAGE_SIZE, 0, 0);
+	if (IS_ERR_VALUE(addr)) {
+		ret = addr;
+		goto up_fail;
+	}
+
+	ret = install_special_mapping(
+			mm,
+			addr,
+			PAGE_SIZE,
+			VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+			&vdso_page);
+	if (ret)
+		goto up_fail;
+
+	mm->context.vdso = (void *)addr;
+
+up_fail:
+	mmap_write_unlock(mm);
+	return ret;
+}
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+	if (vma->vm_mm == NULL)
+		return NULL;
+
+	if (vma->vm_start == (long)vma->vm_mm->context.vdso)
+		return "[vdso]";
+	else
+		return NULL;
+}
diff --git a/arch/csky/kernel/vmlinux.lds.S b/arch/csky/kernel/vmlinux.lds.S
new file mode 100644
index 000000000..f03033e17
--- /dev/null
+++ b/arch/csky/kernel/vmlinux.lds.S
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <asm/vmlinux.lds.h>
+#include <asm/page.h>
+#include <asm/memory.h>
+
+OUTPUT_ARCH(csky)
+ENTRY(_start)
+
+#ifndef __cskyBE__
+jiffies = jiffies_64;
+#else
+jiffies = jiffies_64 + 4;
+#endif
+
+#define VBR_BASE \
+	. = ALIGN(1024); \
+	vec_base = .; \
+	. += 512;
+
+SECTIONS
+{
+	. = PAGE_OFFSET + PHYS_OFFSET_OFFSET;
+
+	_stext = .;
+	__init_begin = .;
+	HEAD_TEXT_SECTION
+	INIT_TEXT_SECTION(PAGE_SIZE)
+	INIT_DATA_SECTION(PAGE_SIZE)
+	PERCPU_SECTION(L1_CACHE_BYTES)
+	. = ALIGN(PAGE_SIZE);
+	__init_end = .;
+
+	.text : AT(ADDR(.text) - LOAD_OFFSET) {
+		_text = .;
+		IRQENTRY_TEXT
+		SOFTIRQENTRY_TEXT
+		TEXT_TEXT
+		SCHED_TEXT
+		CPUIDLE_TEXT
+		LOCK_TEXT
+		KPROBES_TEXT
+		*(.fixup)
+		*(.gnu.warning)
+	} = 0
+	_etext = .;
+
+	/* __init_begin __init_end must be page aligned for free_initmem */
+	. = ALIGN(PAGE_SIZE);
+
+
+	_sdata = .;
+	RO_DATA(PAGE_SIZE)
+	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+	_edata = .;
+
+#ifdef CONFIG_HAVE_TCM
+	.tcm_start : {
+		. = ALIGN(PAGE_SIZE);
+		__tcm_start = .;
+	}
+
+	.text_data_tcm FIXADDR_TCM : AT(__tcm_start)
+	{
+		. = ALIGN(4);
+		__stcm_text_data = .;
+		*(.tcm.text)
+		*(.tcm.rodata)
+#ifndef CONFIG_HAVE_DTCM
+		*(.tcm.data)
+#endif
+		. = ALIGN(4);
+		__etcm_text_data = .;
+	}
+
+	. = ADDR(.tcm_start) + SIZEOF(.tcm_start) + SIZEOF(.text_data_tcm);
+
+#ifdef CONFIG_HAVE_DTCM
+	#define ITCM_SIZE	CONFIG_ITCM_NR_PAGES * PAGE_SIZE
+
+	.dtcm_start : {
+		__dtcm_start = .;
+	}
+
+	.data_tcm FIXADDR_TCM + ITCM_SIZE : AT(__dtcm_start)
+	{
+		. = ALIGN(4);
+		__stcm_data = .;
+		*(.tcm.data)
+		. = ALIGN(4);
+		__etcm_data = .;
+	}
+
+	. = ADDR(.dtcm_start) + SIZEOF(.data_tcm);
+
+	.tcm_end : AT(ADDR(.dtcm_start) + SIZEOF(.data_tcm)) {
+#else
+	.tcm_end : AT(ADDR(.tcm_start) + SIZEOF(.text_data_tcm)) {
+#endif
+		. = ALIGN(PAGE_SIZE);
+		__tcm_end = .;
+	}
+#endif
+
+	EXCEPTION_TABLE(L1_CACHE_BYTES)
+	BSS_SECTION(L1_CACHE_BYTES, PAGE_SIZE, L1_CACHE_BYTES)
+	VBR_BASE
+	_end = . ;
+
+	STABS_DEBUG
+	DWARF_DEBUG
+	ELF_DETAILS
+
+	DISCARDS
+}
diff --git a/arch/csky/lib/Makefile b/arch/csky/lib/Makefile
new file mode 100644
index 000000000..7fbdbb2c4
--- /dev/null
+++ b/arch/csky/lib/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+lib-y  := usercopy.o delay.o
+obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/csky/lib/delay.c b/arch/csky/lib/delay.c
new file mode 100644
index 000000000..22570b079
--- /dev/null
+++ b/arch/csky/lib/delay.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+
+void __delay(unsigned long loops)
+{
+	asm volatile (
+		"mov r0, r0\n"
+		"1:declt %0\n"
+		"bf	1b"
+		: "=r"(loops)
+		: "0"(loops));
+}
+EXPORT_SYMBOL(__delay);
+
+void __const_udelay(unsigned long xloops)
+{
+	unsigned long long loops;
+
+	loops = (unsigned long long)xloops * loops_per_jiffy * HZ;
+
+	__delay(loops >> 32);
+}
+EXPORT_SYMBOL(__const_udelay);
+
+void __udelay(unsigned long usecs)
+{
+	__const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long nsecs)
+{
+	__const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
+}
+EXPORT_SYMBOL(__ndelay);
diff --git a/arch/csky/lib/error-inject.c b/arch/csky/lib/error-inject.c
new file mode 100644
index 000000000..c15fb36fe
--- /dev/null
+++ b/arch/csky/lib/error-inject.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/error-injection.h>
+#include <linux/kprobes.h>
+
+void override_function_with_return(struct pt_regs *regs)
+{
+	instruction_pointer_set(regs, regs->lr);
+}
+NOKPROBE_SYMBOL(override_function_with_return);
diff --git a/arch/csky/lib/usercopy.c b/arch/csky/lib/usercopy.c
new file mode 100644
index 000000000..3c9bd645e
--- /dev/null
+++ b/arch/csky/lib/usercopy.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/uaccess.h>
+#include <linux/types.h>
+
+unsigned long raw_copy_from_user(void *to, const void *from,
+			unsigned long n)
+{
+	___copy_from_user(to, from, n);
+	return n;
+}
+EXPORT_SYMBOL(raw_copy_from_user);
+
+unsigned long raw_copy_to_user(void *to, const void *from,
+			unsigned long n)
+{
+	___copy_to_user(to, from, n);
+	return n;
+}
+EXPORT_SYMBOL(raw_copy_to_user);
+
+
+/*
+ * copy a null terminated string from userspace.
+ */
+#define __do_strncpy_from_user(dst, src, count, res)	\
+do {							\
+	int tmp;					\
+	long faultres;					\
+	asm volatile(					\
+	"       cmpnei  %3, 0           \n"		\
+	"       bf      4f              \n"		\
+	"1:     cmpnei  %1, 0          	\n"		\
+	"       bf      5f              \n"		\
+	"2:     ldb     %4, (%3, 0)     \n"		\
+	"       stb     %4, (%2, 0)     \n"		\
+	"       cmpnei  %4, 0           \n"		\
+	"       bf      3f              \n"		\
+	"       addi    %3,  1          \n"		\
+	"       addi    %2,  1          \n"		\
+	"       subi    %1,  1          \n"		\
+	"       br      1b              \n"		\
+	"3:     subu	%0, %1          \n"		\
+	"       br      5f              \n"		\
+	"4:     mov     %0, %5          \n"		\
+	"       br      5f              \n"		\
+	".section __ex_table, \"a\"     \n"		\
+	".align   2                     \n"		\
+	".long    2b, 4b                \n"		\
+	".previous                      \n"		\
+	"5:                             \n"		\
+	: "=r"(res), "=r"(count), "=r"(dst),		\
+	  "=r"(src), "=r"(tmp),   "=r"(faultres)	\
+	: "5"(-EFAULT), "0"(count), "1"(count),		\
+	  "2"(dst), "3"(src)				\
+	: "memory", "cc");				\
+} while (0)
+
+/*
+ * __strncpy_from_user: - Copy a NUL terminated string from userspace,
+ * with less checking.
+ * @dst:   Destination address, in kernel space.  This buffer must be at
+ *         least @count bytes long.
+ * @src:   Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ * Caller must check the specified block with access_ok() before calling
+ * this function.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+long __strncpy_from_user(char *dst, const char *src, long count)
+{
+	long res;
+
+	__do_strncpy_from_user(dst, src, count, res);
+	return res;
+}
+EXPORT_SYMBOL(__strncpy_from_user);
+
+/*
+ * strncpy_from_user: - Copy a NUL terminated string from userspace.
+ * @dst:   Destination address, in kernel space.  This buffer must be at
+ *         least @count bytes long.
+ * @src:   Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+long strncpy_from_user(char *dst, const char *src, long count)
+{
+	long res = -EFAULT;
+
+	if (access_ok(src, 1))
+		__do_strncpy_from_user(dst, src, count, res);
+	return res;
+}
+EXPORT_SYMBOL(strncpy_from_user);
+
+/*
+ * strlen_user: - Get the size of a string in user space.
+ * @str: The string to measure.
+ * @n:   The maximum valid length
+ *
+ * Get the size of a NUL-terminated string in user space.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ * On exception, returns 0.
+ * If the string is too long, returns a value greater than @n.
+ */
+long strnlen_user(const char *s, long n)
+{
+	unsigned long res, tmp;
+
+	if (s == NULL)
+		return 0;
+
+	asm volatile(
+	"       cmpnei  %1, 0           \n"
+	"       bf      3f              \n"
+	"1:     cmpnei  %0, 0           \n"
+	"       bf      3f              \n"
+	"2:     ldb     %3, (%1, 0)     \n"
+	"       cmpnei  %3, 0           \n"
+	"       bf      3f              \n"
+	"       subi    %0,  1          \n"
+	"       addi    %1,  1          \n"
+	"       br      1b              \n"
+	"3:     subu    %2, %0          \n"
+	"       addi    %2,  1          \n"
+	"       br      5f              \n"
+	"4:     movi    %0, 0           \n"
+	"       br      5f              \n"
+	".section __ex_table, \"a\"     \n"
+	".align   2                     \n"
+	".long    2b, 4b                \n"
+	".previous                      \n"
+	"5:                             \n"
+	: "=r"(n), "=r"(s), "=r"(res), "=r"(tmp)
+	: "0"(n), "1"(s), "2"(n)
+	: "memory", "cc");
+
+	return res;
+}
+EXPORT_SYMBOL(strnlen_user);
+
+#define __do_clear_user(addr, size)			\
+do {							\
+	int __d0, zvalue, tmp;				\
+							\
+	asm volatile(					\
+	"0:     cmpnei  %1, 0           \n"		\
+	"       bf      7f              \n"		\
+	"       mov     %3, %1          \n"		\
+	"       andi    %3, 3           \n"		\
+	"       cmpnei  %3, 0           \n"		\
+	"       bf      1f              \n"		\
+	"       br      5f              \n"		\
+	"1:     cmplti  %0, 32          \n" /* 4W */	\
+	"       bt      3f              \n"		\
+	"8:     stw     %2, (%1, 0)     \n"		\
+	"10:    stw     %2, (%1, 4)     \n"		\
+	"11:    stw     %2, (%1, 8)     \n"		\
+	"12:    stw     %2, (%1, 12)    \n"		\
+	"13:    stw     %2, (%1, 16)    \n"		\
+	"14:    stw     %2, (%1, 20)    \n"		\
+	"15:    stw     %2, (%1, 24)    \n"		\
+	"16:    stw     %2, (%1, 28)    \n"		\
+	"       addi    %1, 32          \n"		\
+	"       subi    %0, 32          \n"		\
+	"       br      1b              \n"		\
+	"3:     cmplti  %0, 4           \n" /* 1W */	\
+	"       bt      5f              \n"		\
+	"4:     stw     %2, (%1, 0)     \n"		\
+	"       addi    %1, 4           \n"		\
+	"       subi    %0, 4           \n"		\
+	"       br      3b              \n"		\
+	"5:     cmpnei  %0, 0           \n" /* 1B */	\
+	"9:     bf      7f              \n"		\
+	"6:     stb     %2, (%1, 0)     \n"		\
+	"       addi    %1,  1          \n"		\
+	"       subi    %0,  1          \n"		\
+	"       br      5b              \n"		\
+	".section __ex_table,\"a\"      \n"		\
+	".align   2                     \n"		\
+	".long    8b, 9b                \n"		\
+	".long    10b, 9b               \n"		\
+	".long    11b, 9b               \n"		\
+	".long    12b, 9b               \n"		\
+	".long    13b, 9b               \n"		\
+	".long    14b, 9b               \n"		\
+	".long    15b, 9b               \n"		\
+	".long    16b, 9b               \n"		\
+	".long    4b, 9b                \n"		\
+	".long    6b, 9b                \n"		\
+	".previous                      \n"		\
+	"7:                             \n"		\
+	: "=r"(size), "=r" (__d0),			\
+	  "=r"(zvalue), "=r"(tmp)			\
+	: "0"(size), "1"(addr), "2"(0)			\
+	: "memory", "cc");				\
+} while (0)
+
+/*
+ * clear_user: - Zero a block of memory in user space.
+ * @to:   Destination address, in user space.
+ * @n:    Number of bytes to zero.
+ *
+ * Zero a block of memory in user space.
+ *
+ * Returns number of bytes that could not be cleared.
+ * On success, this will be zero.
+ */
+unsigned long
+clear_user(void __user *to, unsigned long n)
+{
+	if (access_ok(to, n))
+		__do_clear_user(to, n);
+	return n;
+}
+EXPORT_SYMBOL(clear_user);
+
+/*
+ * __clear_user: - Zero a block of memory in user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @n:    Number of bytes to zero.
+ *
+ * Zero a block of memory in user space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be cleared.
+ * On success, this will be zero.
+ */
+unsigned long
+__clear_user(void __user *to, unsigned long n)
+{
+	__do_clear_user(to, n);
+	return n;
+}
+EXPORT_SYMBOL(__clear_user);
diff --git a/arch/csky/mm/Makefile b/arch/csky/mm/Makefile
new file mode 100644
index 000000000..6e7696e55
--- /dev/null
+++ b/arch/csky/mm/Makefile
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0-only
+ifeq ($(CONFIG_CPU_HAS_CACHEV2),y)
+obj-y +=			cachev2.o
+CFLAGS_REMOVE_cachev2.o = $(CC_FLAGS_FTRACE)
+else
+obj-y +=			cachev1.o
+CFLAGS_REMOVE_cachev1.o = $(CC_FLAGS_FTRACE)
+endif
+
+obj-y +=			dma-mapping.o
+obj-y +=			fault.o
+obj-$(CONFIG_HIGHMEM) +=	highmem.o
+obj-y +=			init.o
+obj-y +=			ioremap.o
+obj-y +=			syscache.o
+obj-y +=			tlb.o
+obj-y +=			asid.o
+obj-y +=			context.o
+obj-$(CONFIG_HAVE_TCM) +=	tcm.o
diff --git a/arch/csky/mm/asid.c b/arch/csky/mm/asid.c
new file mode 100644
index 000000000..b2e914745
--- /dev/null
+++ b/arch/csky/mm/asid.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic ASID allocator.
+ *
+ * Based on arch/arm/mm/context.c
+ *
+ * Copyright (C) 2002-2003 Deep Blue Solutions Ltd, all rights reserved.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/slab.h>
+#include <linux/mm_types.h>
+
+#include <asm/asid.h>
+
+#define reserved_asid(info, cpu) *per_cpu_ptr((info)->reserved, cpu)
+
+#define ASID_MASK(info)			(~GENMASK((info)->bits - 1, 0))
+#define ASID_FIRST_VERSION(info)	(1UL << ((info)->bits))
+
+#define asid2idx(info, asid)		(((asid) & ~ASID_MASK(info)) >> (info)->ctxt_shift)
+#define idx2asid(info, idx)		(((idx) << (info)->ctxt_shift) & ~ASID_MASK(info))
+
+static void flush_context(struct asid_info *info)
+{
+	int i;
+	u64 asid;
+
+	/* Update the list of reserved ASIDs and the ASID bitmap. */
+	bitmap_clear(info->map, 0, NUM_CTXT_ASIDS(info));
+
+	for_each_possible_cpu(i) {
+		asid = atomic64_xchg_relaxed(&active_asid(info, i), 0);
+		/*
+		 * If this CPU has already been through a
+		 * rollover, but hasn't run another task in
+		 * the meantime, we must preserve its reserved
+		 * ASID, as this is the only trace we have of
+		 * the process it is still running.
+		 */
+		if (asid == 0)
+			asid = reserved_asid(info, i);
+		__set_bit(asid2idx(info, asid), info->map);
+		reserved_asid(info, i) = asid;
+	}
+
+	/*
+	 * Queue a TLB invalidation for each CPU to perform on next
+	 * context-switch
+	 */
+	cpumask_setall(&info->flush_pending);
+}
+
+static bool check_update_reserved_asid(struct asid_info *info, u64 asid,
+				       u64 newasid)
+{
+	int cpu;
+	bool hit = false;
+
+	/*
+	 * Iterate over the set of reserved ASIDs looking for a match.
+	 * If we find one, then we can update our mm to use newasid
+	 * (i.e. the same ASID in the current generation) but we can't
+	 * exit the loop early, since we need to ensure that all copies
+	 * of the old ASID are updated to reflect the mm. Failure to do
+	 * so could result in us missing the reserved ASID in a future
+	 * generation.
+	 */
+	for_each_possible_cpu(cpu) {
+		if (reserved_asid(info, cpu) == asid) {
+			hit = true;
+			reserved_asid(info, cpu) = newasid;
+		}
+	}
+
+	return hit;
+}
+
+static u64 new_context(struct asid_info *info, atomic64_t *pasid,
+		       struct mm_struct *mm)
+{
+	static u32 cur_idx = 1;
+	u64 asid = atomic64_read(pasid);
+	u64 generation = atomic64_read(&info->generation);
+
+	if (asid != 0) {
+		u64 newasid = generation | (asid & ~ASID_MASK(info));
+
+		/*
+		 * If our current ASID was active during a rollover, we
+		 * can continue to use it and this was just a false alarm.
+		 */
+		if (check_update_reserved_asid(info, asid, newasid))
+			return newasid;
+
+		/*
+		 * We had a valid ASID in a previous life, so try to re-use
+		 * it if possible.
+		 */
+		if (!__test_and_set_bit(asid2idx(info, asid), info->map))
+			return newasid;
+	}
+
+	/*
+	 * Allocate a free ASID. If we can't find one, take a note of the
+	 * currently active ASIDs and mark the TLBs as requiring flushes.  We
+	 * always count from ASID #2 (index 1), as we use ASID #0 when setting
+	 * a reserved TTBR0 for the init_mm and we allocate ASIDs in even/odd
+	 * pairs.
+	 */
+	asid = find_next_zero_bit(info->map, NUM_CTXT_ASIDS(info), cur_idx);
+	if (asid != NUM_CTXT_ASIDS(info))
+		goto set_asid;
+
+	/* We're out of ASIDs, so increment the global generation count */
+	generation = atomic64_add_return_relaxed(ASID_FIRST_VERSION(info),
+						 &info->generation);
+	flush_context(info);
+
+	/* We have more ASIDs than CPUs, so this will always succeed */
+	asid = find_next_zero_bit(info->map, NUM_CTXT_ASIDS(info), 1);
+
+set_asid:
+	__set_bit(asid, info->map);
+	cur_idx = asid;
+	cpumask_clear(mm_cpumask(mm));
+	return idx2asid(info, asid) | generation;
+}
+
+/*
+ * Generate a new ASID for the context.
+ *
+ * @pasid: Pointer to the current ASID batch allocated. It will be updated
+ * with the new ASID batch.
+ * @cpu: current CPU ID. Must have been acquired through get_cpu()
+ */
+void asid_new_context(struct asid_info *info, atomic64_t *pasid,
+		      unsigned int cpu, struct mm_struct *mm)
+{
+	unsigned long flags;
+	u64 asid;
+
+	raw_spin_lock_irqsave(&info->lock, flags);
+	/* Check that our ASID belongs to the current generation. */
+	asid = atomic64_read(pasid);
+	if ((asid ^ atomic64_read(&info->generation)) >> info->bits) {
+		asid = new_context(info, pasid, mm);
+		atomic64_set(pasid, asid);
+	}
+
+	if (cpumask_test_and_clear_cpu(cpu, &info->flush_pending))
+		info->flush_cpu_ctxt_cb();
+
+	atomic64_set(&active_asid(info, cpu), asid);
+	cpumask_set_cpu(cpu, mm_cpumask(mm));
+	raw_spin_unlock_irqrestore(&info->lock, flags);
+}
+
+/*
+ * Initialize the ASID allocator
+ *
+ * @info: Pointer to the asid allocator structure
+ * @bits: Number of ASIDs available
+ * @asid_per_ctxt: Number of ASIDs to allocate per-context. ASIDs are
+ * allocated contiguously for a given context. This value should be a power of
+ * 2.
+ */
+int asid_allocator_init(struct asid_info *info,
+			u32 bits, unsigned int asid_per_ctxt,
+			void (*flush_cpu_ctxt_cb)(void))
+{
+	info->bits = bits;
+	info->ctxt_shift = ilog2(asid_per_ctxt);
+	info->flush_cpu_ctxt_cb = flush_cpu_ctxt_cb;
+	/*
+	 * Expect allocation after rollover to fail if we don't have at least
+	 * one more ASID than CPUs. ASID #0 is always reserved.
+	 */
+	WARN_ON(NUM_CTXT_ASIDS(info) - 1 <= num_possible_cpus());
+	atomic64_set(&info->generation, ASID_FIRST_VERSION(info));
+	info->map = kcalloc(BITS_TO_LONGS(NUM_CTXT_ASIDS(info)),
+			    sizeof(*info->map), GFP_KERNEL);
+	if (!info->map)
+		return -ENOMEM;
+
+	raw_spin_lock_init(&info->lock);
+
+	return 0;
+}
diff --git a/arch/csky/mm/cachev1.c b/arch/csky/mm/cachev1.c
new file mode 100644
index 000000000..5a5a9804a
--- /dev/null
+++ b/arch/csky/mm/cachev1.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/spinlock.h>
+#include <asm/cache.h>
+#include <abi/reg_ops.h>
+
+/* for L1-cache */
+#define INS_CACHE		(1 << 0)
+#define DATA_CACHE		(1 << 1)
+#define CACHE_INV		(1 << 4)
+#define CACHE_CLR		(1 << 5)
+#define CACHE_OMS		(1 << 6)
+#define CACHE_ITS		(1 << 7)
+#define CACHE_LICF		(1 << 31)
+
+/* for L2-cache */
+#define CR22_LEVEL_SHIFT	(1)
+#define CR22_SET_SHIFT		(7)
+#define CR22_WAY_SHIFT		(30)
+#define CR22_WAY_SHIFT_L2	(29)
+
+static DEFINE_SPINLOCK(cache_lock);
+
+static inline void cache_op_line(unsigned long i, unsigned int val)
+{
+	mtcr("cr22", i);
+	mtcr("cr17", val);
+}
+
+#define CCR2_L2E (1 << 3)
+static void cache_op_all(unsigned int value, unsigned int l2)
+{
+	mtcr("cr17", value | CACHE_CLR);
+	mb();
+
+	if (l2 && (mfcr_ccr2() & CCR2_L2E)) {
+		mtcr("cr24", value | CACHE_CLR);
+		mb();
+	}
+}
+
+static void cache_op_range(
+	unsigned int start,
+	unsigned int end,
+	unsigned int value,
+	unsigned int l2)
+{
+	unsigned long i, flags;
+	unsigned int val = value | CACHE_CLR | CACHE_OMS;
+	bool l2_sync;
+
+	if (unlikely((end - start) >= PAGE_SIZE) ||
+	    unlikely(start < PAGE_OFFSET) ||
+	    unlikely(start >= PAGE_OFFSET + LOWMEM_LIMIT)) {
+		cache_op_all(value, l2);
+		return;
+	}
+
+	if ((mfcr_ccr2() & CCR2_L2E) && l2)
+		l2_sync = 1;
+	else
+		l2_sync = 0;
+
+	spin_lock_irqsave(&cache_lock, flags);
+
+	i = start & ~(L1_CACHE_BYTES - 1);
+	for (; i < end; i += L1_CACHE_BYTES) {
+		cache_op_line(i, val);
+		if (l2_sync) {
+			mb();
+			mtcr("cr24", val);
+		}
+	}
+	spin_unlock_irqrestore(&cache_lock, flags);
+
+	mb();
+}
+
+void dcache_wb_line(unsigned long start)
+{
+	asm volatile("idly4\n":::"memory");
+	cache_op_line(start, DATA_CACHE|CACHE_CLR);
+	mb();
+}
+
+void icache_inv_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, INS_CACHE|CACHE_INV, 0);
+}
+
+void icache_inv_all(void)
+{
+	cache_op_all(INS_CACHE|CACHE_INV, 0);
+}
+
+void local_icache_inv_all(void *priv)
+{
+	cache_op_all(INS_CACHE|CACHE_INV, 0);
+}
+
+void dcache_wb_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, DATA_CACHE|CACHE_CLR, 0);
+}
+
+void dcache_wbinv_all(void)
+{
+	cache_op_all(DATA_CACHE|CACHE_CLR|CACHE_INV, 0);
+}
+
+void cache_wbinv_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, INS_CACHE|DATA_CACHE|CACHE_CLR|CACHE_INV, 0);
+}
+EXPORT_SYMBOL(cache_wbinv_range);
+
+void cache_wbinv_all(void)
+{
+	cache_op_all(INS_CACHE|DATA_CACHE|CACHE_CLR|CACHE_INV, 0);
+}
+
+void dma_wbinv_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, DATA_CACHE|CACHE_CLR|CACHE_INV, 1);
+}
+
+void dma_inv_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, DATA_CACHE|CACHE_CLR|CACHE_INV, 1);
+}
+
+void dma_wb_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, DATA_CACHE|CACHE_CLR|CACHE_INV, 1);
+}
diff --git a/arch/csky/mm/cachev2.c b/arch/csky/mm/cachev2.c
new file mode 100644
index 000000000..7a9664adc
--- /dev/null
+++ b/arch/csky/mm/cachev2.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+#include <asm/cache.h>
+#include <asm/barrier.h>
+
+/* for L1-cache */
+#define INS_CACHE		(1 << 0)
+#define DATA_CACHE		(1 << 1)
+#define CACHE_INV		(1 << 4)
+#define CACHE_CLR		(1 << 5)
+#define CACHE_OMS		(1 << 6)
+
+void local_icache_inv_all(void *priv)
+{
+	mtcr("cr17", INS_CACHE|CACHE_INV);
+	sync_is();
+}
+
+#ifdef CONFIG_CPU_HAS_ICACHE_INS
+void icache_inv_range(unsigned long start, unsigned long end)
+{
+	unsigned long i = start & ~(L1_CACHE_BYTES - 1);
+
+	for (; i < end; i += L1_CACHE_BYTES)
+		asm volatile("icache.iva %0\n"::"r"(i):"memory");
+	sync_is();
+}
+#else
+struct cache_range {
+	unsigned long start;
+	unsigned long end;
+};
+
+static DEFINE_SPINLOCK(cache_lock);
+
+static inline void cache_op_line(unsigned long i, unsigned int val)
+{
+	mtcr("cr22", i);
+	mtcr("cr17", val);
+}
+
+void local_icache_inv_range(void *priv)
+{
+	struct cache_range *param = priv;
+	unsigned long i = param->start & ~(L1_CACHE_BYTES - 1);
+	unsigned long flags;
+
+	spin_lock_irqsave(&cache_lock, flags);
+
+	for (; i < param->end; i += L1_CACHE_BYTES)
+		cache_op_line(i, INS_CACHE | CACHE_INV | CACHE_OMS);
+
+	spin_unlock_irqrestore(&cache_lock, flags);
+
+	sync_is();
+}
+
+void icache_inv_range(unsigned long start, unsigned long end)
+{
+	struct cache_range param = { start, end };
+
+	if (irqs_disabled())
+		local_icache_inv_range(&param);
+	else
+		on_each_cpu(local_icache_inv_range, &param, 1);
+}
+#endif
+
+inline void dcache_wb_line(unsigned long start)
+{
+	asm volatile("dcache.cval1 %0\n"::"r"(start):"memory");
+	sync_is();
+}
+
+void dcache_wb_range(unsigned long start, unsigned long end)
+{
+	unsigned long i = start & ~(L1_CACHE_BYTES - 1);
+
+	for (; i < end; i += L1_CACHE_BYTES)
+		asm volatile("dcache.cval1 %0\n"::"r"(i):"memory");
+	sync_is();
+}
+
+void cache_wbinv_range(unsigned long start, unsigned long end)
+{
+	dcache_wb_range(start, end);
+	icache_inv_range(start, end);
+}
+EXPORT_SYMBOL(cache_wbinv_range);
+
+void dma_wbinv_range(unsigned long start, unsigned long end)
+{
+	unsigned long i = start & ~(L1_CACHE_BYTES - 1);
+
+	for (; i < end; i += L1_CACHE_BYTES)
+		asm volatile("dcache.civa %0\n"::"r"(i):"memory");
+	sync_is();
+}
+
+void dma_inv_range(unsigned long start, unsigned long end)
+{
+	unsigned long i = start & ~(L1_CACHE_BYTES - 1);
+
+	for (; i < end; i += L1_CACHE_BYTES)
+		asm volatile("dcache.iva %0\n"::"r"(i):"memory");
+	sync_is();
+}
+
+void dma_wb_range(unsigned long start, unsigned long end)
+{
+	unsigned long i = start & ~(L1_CACHE_BYTES - 1);
+
+	for (; i < end; i += L1_CACHE_BYTES)
+		asm volatile("dcache.cva %0\n"::"r"(i):"memory");
+	sync_is();
+}
diff --git a/arch/csky/mm/context.c b/arch/csky/mm/context.c
new file mode 100644
index 000000000..0d95bdd93
--- /dev/null
+++ b/arch/csky/mm/context.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/bitops.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+
+#include <asm/asid.h>
+#include <asm/mmu_context.h>
+#include <asm/smp.h>
+#include <asm/tlbflush.h>
+
+static DEFINE_PER_CPU(atomic64_t, active_asids);
+static DEFINE_PER_CPU(u64, reserved_asids);
+
+struct asid_info asid_info;
+
+void check_and_switch_context(struct mm_struct *mm, unsigned int cpu)
+{
+	asid_check_context(&asid_info, &mm->context.asid, cpu, mm);
+}
+
+static void asid_flush_cpu_ctxt(void)
+{
+	local_tlb_invalid_all();
+}
+
+static int asids_init(void)
+{
+	BUG_ON(((1 << CONFIG_CPU_ASID_BITS) - 1) <= num_possible_cpus());
+
+	if (asid_allocator_init(&asid_info, CONFIG_CPU_ASID_BITS, 1,
+				asid_flush_cpu_ctxt))
+		panic("Unable to initialize ASID allocator for %lu ASIDs\n",
+		      NUM_ASIDS(&asid_info));
+
+	asid_info.active = &active_asids;
+	asid_info.reserved = &reserved_asids;
+
+	pr_info("ASID allocator initialised with %lu entries\n",
+		NUM_CTXT_ASIDS(&asid_info));
+
+	return 0;
+}
+early_initcall(asids_init);
diff --git a/arch/csky/mm/dma-mapping.c b/arch/csky/mm/dma-mapping.c
new file mode 100644
index 000000000..c3a775a7e
--- /dev/null
+++ b/arch/csky/mm/dma-mapping.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/cache.h>
+#include <linux/dma-map-ops.h>
+#include <linux/genalloc.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/types.h>
+#include <linux/version.h>
+#include <asm/cache.h>
+
+static inline void cache_op(phys_addr_t paddr, size_t size,
+			    void (*fn)(unsigned long start, unsigned long end))
+{
+	struct page *page    = phys_to_page(paddr);
+	void *start          = __va(page_to_phys(page));
+	unsigned long offset = offset_in_page(paddr);
+	size_t left          = size;
+
+	do {
+		size_t len = left;
+
+		if (offset + len > PAGE_SIZE)
+			len = PAGE_SIZE - offset;
+
+		if (PageHighMem(page)) {
+			start = kmap_atomic(page);
+
+			fn((unsigned long)start + offset,
+					(unsigned long)start + offset + len);
+
+			kunmap_atomic(start);
+		} else {
+			fn((unsigned long)start + offset,
+					(unsigned long)start + offset + len);
+		}
+		offset = 0;
+
+		page++;
+		start += PAGE_SIZE;
+		left -= len;
+	} while (left);
+}
+
+static void dma_wbinv_set_zero_range(unsigned long start, unsigned long end)
+{
+	memset((void *)start, 0, end - start);
+	dma_wbinv_range(start, end);
+}
+
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
+	cache_op(page_to_phys(page), size, dma_wbinv_set_zero_range);
+}
+
+void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
+		enum dma_data_direction dir)
+{
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		cache_op(paddr, size, dma_wb_range);
+		break;
+	case DMA_FROM_DEVICE:
+	case DMA_BIDIRECTIONAL:
+		cache_op(paddr, size, dma_wbinv_range);
+		break;
+	default:
+		BUG();
+	}
+}
+
+void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
+		enum dma_data_direction dir)
+{
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		return;
+	case DMA_FROM_DEVICE:
+	case DMA_BIDIRECTIONAL:
+		cache_op(paddr, size, dma_inv_range);
+		break;
+	default:
+		BUG();
+	}
+}
diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
new file mode 100644
index 000000000..081b178b4
--- /dev/null
+++ b/arch/csky/mm/fault.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/signal.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/version.h>
+#include <linux/vt_kern.h>
+#include <linux/extable.h>
+#include <linux/uaccess.h>
+#include <linux/perf_event.h>
+#include <linux/kprobes.h>
+
+#include <asm/hardirq.h>
+#include <asm/mmu_context.h>
+#include <asm/traps.h>
+#include <asm/page.h>
+
+int fixup_exception(struct pt_regs *regs)
+{
+	const struct exception_table_entry *fixup;
+
+	fixup = search_exception_tables(instruction_pointer(regs));
+	if (fixup) {
+		regs->pc = fixup->nextinsn;
+
+		return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * This routine handles page faults. It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ */
+asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
+			      unsigned long mmu_meh)
+{
+	struct vm_area_struct *vma = NULL;
+	struct task_struct *tsk = current;
+	struct mm_struct *mm = tsk->mm;
+	int si_code;
+	int fault;
+	unsigned long address = mmu_meh & PAGE_MASK;
+
+	if (kprobe_page_fault(regs, tsk->thread.trap_no))
+		return;
+
+	si_code = SEGV_MAPERR;
+
+#ifndef CONFIG_CPU_HAS_TLBI
+	/*
+	 * We fault-in kernel-space virtual memory on-demand. The
+	 * 'reference' page table is init_mm.pgd.
+	 *
+	 * NOTE! We MUST NOT take any locks for this case. We may
+	 * be in an interrupt or a critical region, and should
+	 * only copy the information from the master page table,
+	 * nothing more.
+	 */
+	if (unlikely(address >= VMALLOC_START) &&
+	    unlikely(address <= VMALLOC_END)) {
+		/*
+		 * Synchronize this task's top level page-table
+		 * with the 'reference' page table.
+		 *
+		 * Do _not_ use "tsk" here. We might be inside
+		 * an interrupt in the middle of a task switch..
+		 */
+		int offset = pgd_index(address);
+		pgd_t *pgd, *pgd_k;
+		pud_t *pud, *pud_k;
+		pmd_t *pmd, *pmd_k;
+		pte_t *pte_k;
+
+		unsigned long pgd_base;
+
+		pgd_base = (unsigned long)__va(get_pgd());
+		pgd = (pgd_t *)pgd_base + offset;
+		pgd_k = init_mm.pgd + offset;
+
+		if (!pgd_present(*pgd_k))
+			goto no_context;
+		set_pgd(pgd, *pgd_k);
+
+		pud = (pud_t *)pgd;
+		pud_k = (pud_t *)pgd_k;
+		if (!pud_present(*pud_k))
+			goto no_context;
+
+		pmd = pmd_offset(pud, address);
+		pmd_k = pmd_offset(pud_k, address);
+		if (!pmd_present(*pmd_k))
+			goto no_context;
+		set_pmd(pmd, *pmd_k);
+
+		pte_k = pte_offset_kernel(pmd_k, address);
+		if (!pte_present(*pte_k))
+			goto no_context;
+		return;
+	}
+#endif
+
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+	/*
+	 * If we're in an interrupt or have no user
+	 * context, we must not take the fault..
+	 */
+	if (in_atomic() || !mm)
+		goto bad_area_nosemaphore;
+
+	mmap_read_lock(mm);
+	vma = find_vma(mm, address);
+	if (!vma)
+		goto bad_area;
+	if (vma->vm_start <= address)
+		goto good_area;
+	if (!(vma->vm_flags & VM_GROWSDOWN))
+		goto bad_area;
+	if (expand_stack(vma, address))
+		goto bad_area;
+	/*
+	 * Ok, we have a good vm_area for this memory access, so
+	 * we can handle it..
+	 */
+good_area:
+	si_code = SEGV_ACCERR;
+
+	if (write) {
+		if (!(vma->vm_flags & VM_WRITE))
+			goto bad_area;
+	} else {
+		if (unlikely(!vma_is_accessible(vma)))
+			goto bad_area;
+	}
+
+	/*
+	 * If for any reason at all we couldn't handle the fault,
+	 * make sure we exit gracefully rather than endlessly redo
+	 * the fault.
+	 */
+	fault = handle_mm_fault(vma, address, write ? FAULT_FLAG_WRITE : 0,
+				regs);
+	if (unlikely(fault & VM_FAULT_ERROR)) {
+		if (fault & VM_FAULT_OOM)
+			goto out_of_memory;
+		else if (fault & VM_FAULT_SIGBUS)
+			goto do_sigbus;
+		else if (fault & VM_FAULT_SIGSEGV)
+			goto bad_area;
+		BUG();
+	}
+	mmap_read_unlock(mm);
+	return;
+
+	/*
+	 * Something tried to access memory that isn't in our memory map..
+	 * Fix it, but check if it's kernel or user first..
+	 */
+bad_area:
+	mmap_read_unlock(mm);
+
+bad_area_nosemaphore:
+	/* User mode accesses just cause a SIGSEGV */
+	if (user_mode(regs)) {
+		tsk->thread.trap_no = trap_no(regs);
+		force_sig_fault(SIGSEGV, si_code, (void __user *)address);
+		return;
+	}
+
+no_context:
+	tsk->thread.trap_no = trap_no(regs);
+
+	/* Are we prepared to handle this kernel fault? */
+	if (fixup_exception(regs))
+		return;
+
+	/*
+	 * Oops. The kernel tried to access some bad page. We'll have to
+	 * terminate things with extreme prejudice.
+	 */
+	bust_spinlocks(1);
+	pr_alert("Unable to handle kernel paging request at virtual "
+		 "address 0x%08lx, pc: 0x%08lx\n", address, regs->pc);
+	die(regs, "Oops");
+
+out_of_memory:
+	tsk->thread.trap_no = trap_no(regs);
+
+	/*
+	 * We ran out of memory, call the OOM killer, and return the userspace
+	 * (which will retry the fault, or kill us if we got oom-killed).
+	 */
+	pagefault_out_of_memory();
+	return;
+
+do_sigbus:
+	tsk->thread.trap_no = trap_no(regs);
+
+	mmap_read_unlock(mm);
+
+	/* Kernel mode? Handle exceptions or die */
+	if (!user_mode(regs))
+		goto no_context;
+
+	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
+}
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
new file mode 100644
index 000000000..89c10800a
--- /dev/null
+++ b/arch/csky/mm/highmem.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/module.h>
+#include <linux/highmem.h>
+#include <linux/smp.h>
+#include <linux/memblock.h>
+#include <asm/fixmap.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+
+static pte_t *kmap_pte;
+
+unsigned long highstart_pfn, highend_pfn;
+
+void kmap_flush_tlb(unsigned long addr)
+{
+	flush_tlb_one(addr);
+}
+EXPORT_SYMBOL(kmap_flush_tlb);
+
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
+{
+	unsigned long vaddr;
+	int idx, type;
+
+	type = kmap_atomic_idx_push();
+	idx = type + KM_TYPE_NR*smp_processor_id();
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+#ifdef CONFIG_DEBUG_HIGHMEM
+	BUG_ON(!pte_none(*(kmap_pte - idx)));
+#endif
+	set_pte(kmap_pte-idx, mk_pte(page, prot));
+	flush_tlb_one((unsigned long)vaddr);
+
+	return (void *)vaddr;
+}
+EXPORT_SYMBOL(kmap_atomic_high_prot);
+
+void kunmap_atomic_high(void *kvaddr)
+{
+	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
+	int idx;
+
+	if (vaddr < FIXADDR_START)
+		return;
+
+#ifdef CONFIG_DEBUG_HIGHMEM
+	idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
+
+	BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
+
+	pte_clear(&init_mm, vaddr, kmap_pte - idx);
+	flush_tlb_one(vaddr);
+#else
+	(void) idx; /* to kill a warning */
+#endif
+	kmap_atomic_idx_pop();
+}
+EXPORT_SYMBOL(kunmap_atomic_high);
+
+/*
+ * This is the same as kmap_atomic() but can map memory that doesn't
+ * have a struct page associated with it.
+ */
+void *kmap_atomic_pfn(unsigned long pfn)
+{
+	unsigned long vaddr;
+	int idx, type;
+
+	pagefault_disable();
+
+	type = kmap_atomic_idx_push();
+	idx = type + KM_TYPE_NR*smp_processor_id();
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+	set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
+	flush_tlb_one(vaddr);
+
+	return (void *) vaddr;
+}
+
+static void __init kmap_pages_init(void)
+{
+	unsigned long vaddr;
+	pgd_t *pgd;
+	pmd_t *pmd;
+	pud_t *pud;
+	pte_t *pte;
+
+	vaddr = PKMAP_BASE;
+	fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
+
+	pgd = swapper_pg_dir + pgd_index(vaddr);
+	pud = (pud_t *)pgd;
+	pmd = pmd_offset(pud, vaddr);
+	pte = pte_offset_kernel(pmd, vaddr);
+	pkmap_page_table = pte;
+}
+
+void __init kmap_init(void)
+{
+	unsigned long vaddr;
+
+	kmap_pages_init();
+
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
+
+	kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
+}
diff --git a/arch/csky/mm/init.c b/arch/csky/mm/init.c
new file mode 100644
index 000000000..af6271283
--- /dev/null
+++ b/arch/csky/mm/init.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/bug.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/pagemap.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/memblock.h>
+#include <linux/swap.h>
+#include <linux/proc_fs.h>
+#include <linux/pfn.h>
+#include <linux/initrd.h>
+
+#include <asm/setup.h>
+#include <asm/cachectl.h>
+#include <asm/dma.h>
+#include <asm/pgalloc.h>
+#include <asm/mmu_context.h>
+#include <asm/sections.h>
+#include <asm/tlb.h>
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
+pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
+EXPORT_SYMBOL(invalid_pte_table);
+unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
+						__page_aligned_bss;
+EXPORT_SYMBOL(empty_zero_page);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+static void __init setup_initrd(void)
+{
+	unsigned long size;
+
+	if (initrd_start >= initrd_end) {
+		pr_err("initrd not found or empty");
+		goto disable;
+	}
+
+	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
+		pr_err("initrd extends beyond end of memory");
+		goto disable;
+	}
+
+	size = initrd_end - initrd_start;
+
+	if (memblock_is_region_reserved(__pa(initrd_start), size)) {
+		pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region",
+		       __pa(initrd_start), size);
+		goto disable;
+	}
+
+	memblock_reserve(__pa(initrd_start), size);
+
+	pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
+		(void *)(initrd_start), size);
+
+	initrd_below_start_ok = 1;
+
+	return;
+
+disable:
+	initrd_start = initrd_end = 0;
+
+	pr_err(" - disabling initrd\n");
+}
+#endif
+
+void __init mem_init(void)
+{
+#ifdef CONFIG_HIGHMEM
+	unsigned long tmp;
+
+	max_mapnr = highend_pfn;
+#else
+	max_mapnr = max_low_pfn;
+#endif
+	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	setup_initrd();
+#endif
+
+	memblock_free_all();
+
+#ifdef CONFIG_HIGHMEM
+	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
+		struct page *page = pfn_to_page(tmp);
+
+		/* FIXME not sure about */
+		if (!memblock_is_reserved(tmp << PAGE_SHIFT))
+			free_highmem_page(page);
+	}
+#endif
+	mem_init_print_info(NULL);
+}
+
+extern char __init_begin[], __init_end[];
+
+void free_initmem(void)
+{
+	unsigned long addr;
+
+	addr = (unsigned long) &__init_begin;
+
+	while (addr < (unsigned long) &__init_end) {
+		ClearPageReserved(virt_to_page(addr));
+		init_page_count(virt_to_page(addr));
+		free_page(addr);
+		totalram_pages_inc();
+		addr += PAGE_SIZE;
+	}
+
+	pr_info("Freeing unused kernel memory: %dk freed\n",
+	((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
+}
+
+void pgd_init(unsigned long *p)
+{
+	int i;
+
+	for (i = 0; i < PTRS_PER_PGD; i++)
+		p[i] = __pa(invalid_pte_table);
+}
+
+void __init pre_mmu_init(void)
+{
+	/*
+	 * Setup page-table and enable TLB-hardrefill
+	 */
+	flush_tlb_all();
+	pgd_init((unsigned long *)swapper_pg_dir);
+	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
+	TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
+
+	/* Setup page mask to 4k */
+	write_mmu_pagemask(0);
+}
+
+void __init fixrange_init(unsigned long start, unsigned long end,
+			pgd_t *pgd_base)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	int i, j, k;
+	unsigned long vaddr;
+
+	vaddr = start;
+	i = pgd_index(vaddr);
+	j = pud_index(vaddr);
+	k = pmd_index(vaddr);
+	pgd = pgd_base + i;
+
+	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
+		pud = (pud_t *)pgd;
+		for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
+			pmd = (pmd_t *)pud;
+			for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
+				if (pmd_none(*pmd)) {
+					pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
+					if (!pte)
+						panic("%s: Failed to allocate %lu bytes align=%lx\n",
+						      __func__, PAGE_SIZE,
+						      PAGE_SIZE);
+
+					set_pmd(pmd, __pmd(__pa(pte)));
+					BUG_ON(pte != pte_offset_kernel(pmd, 0));
+				}
+				vaddr += PMD_SIZE;
+			}
+			k = 0;
+		}
+		j = 0;
+	}
+}
+
+void __init fixaddr_init(void)
+{
+	unsigned long vaddr;
+
+	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
+	fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
+}
diff --git a/arch/csky/mm/ioremap.c b/arch/csky/mm/ioremap.c
new file mode 100644
index 000000000..70c8268d3
--- /dev/null
+++ b/arch/csky/mm/ioremap.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+			      unsigned long size, pgprot_t vma_prot)
+{
+	if (!pfn_valid(pfn)) {
+		return pgprot_noncached(vma_prot);
+	} else if (file->f_flags & O_SYNC) {
+		return pgprot_writecombine(vma_prot);
+	}
+
+	return vma_prot;
+}
+EXPORT_SYMBOL(phys_mem_access_prot);
diff --git a/arch/csky/mm/syscache.c b/arch/csky/mm/syscache.c
new file mode 100644
index 000000000..cd847ad62
--- /dev/null
+++ b/arch/csky/mm/syscache.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/syscalls.h>
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+#include <asm/cachectl.h>
+
+SYSCALL_DEFINE3(cacheflush,
+		void __user *, addr,
+		unsigned long, bytes,
+		int, cache)
+{
+	switch (cache) {
+	case BCACHE:
+	case DCACHE:
+		dcache_wb_range((unsigned long)addr,
+				(unsigned long)addr + bytes);
+		if (cache != BCACHE)
+			break;
+		fallthrough;
+	case ICACHE:
+		flush_icache_mm_range(current->mm,
+				(unsigned long)addr,
+				(unsigned long)addr + bytes);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
diff --git a/arch/csky/mm/tcm.c b/arch/csky/mm/tcm.c
new file mode 100644
index 000000000..ddeb36328
--- /dev/null
+++ b/arch/csky/mm/tcm.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/highmem.h>
+#include <linux/genalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/fixmap.h>
+
+#if (CONFIG_ITCM_RAM_BASE == 0xffffffff)
+#error "You should define ITCM_RAM_BASE"
+#endif
+
+#ifdef CONFIG_HAVE_DTCM
+#if (CONFIG_DTCM_RAM_BASE == 0xffffffff)
+#error "You should define DTCM_RAM_BASE"
+#endif
+
+#if (CONFIG_DTCM_RAM_BASE == CONFIG_ITCM_RAM_BASE)
+#error "You should define correct DTCM_RAM_BASE"
+#endif
+#endif
+
+extern char __tcm_start, __tcm_end, __dtcm_start;
+
+static struct gen_pool *tcm_pool;
+
+static void __init tcm_mapping_init(void)
+{
+	pte_t *tcm_pte;
+	unsigned long vaddr, paddr;
+	int i;
+
+	paddr = CONFIG_ITCM_RAM_BASE;
+
+	if (pfn_valid(PFN_DOWN(CONFIG_ITCM_RAM_BASE)))
+		goto panic;
+
+#ifndef CONFIG_HAVE_DTCM
+	for (i = 0; i < TCM_NR_PAGES; i++) {
+#else
+	for (i = 0; i < CONFIG_ITCM_NR_PAGES; i++) {
+#endif
+		vaddr = __fix_to_virt(FIX_TCM - i);
+
+		tcm_pte =
+			pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
+
+		set_pte(tcm_pte, pfn_pte(__phys_to_pfn(paddr), PAGE_KERNEL));
+
+		flush_tlb_one(vaddr);
+
+		paddr = paddr + PAGE_SIZE;
+	}
+
+#ifdef CONFIG_HAVE_DTCM
+	if (pfn_valid(PFN_DOWN(CONFIG_DTCM_RAM_BASE)))
+		goto panic;
+
+	paddr = CONFIG_DTCM_RAM_BASE;
+
+	for (i = 0; i < CONFIG_DTCM_NR_PAGES; i++) {
+		vaddr = __fix_to_virt(FIX_TCM - CONFIG_ITCM_NR_PAGES - i);
+
+		tcm_pte =
+			pte_offset_kernel((pmd_t *) pgd_offset_k(vaddr), vaddr);
+
+		set_pte(tcm_pte, pfn_pte(__phys_to_pfn(paddr), PAGE_KERNEL));
+
+		flush_tlb_one(vaddr);
+
+		paddr = paddr + PAGE_SIZE;
+	}
+#endif
+
+#ifndef CONFIG_HAVE_DTCM
+	memcpy((void *)__fix_to_virt(FIX_TCM),
+				&__tcm_start, &__tcm_end - &__tcm_start);
+
+	pr_info("%s: mapping tcm va:0x%08lx to pa:0x%08x\n",
+			__func__, __fix_to_virt(FIX_TCM), CONFIG_ITCM_RAM_BASE);
+
+	pr_info("%s: __tcm_start va:0x%08lx size:%d\n",
+			__func__, (unsigned long)&__tcm_start, &__tcm_end - &__tcm_start);
+#else
+	memcpy((void *)__fix_to_virt(FIX_TCM),
+				&__tcm_start, &__dtcm_start - &__tcm_start);
+
+	pr_info("%s: mapping itcm va:0x%08lx to pa:0x%08x\n",
+			__func__, __fix_to_virt(FIX_TCM), CONFIG_ITCM_RAM_BASE);
+
+	pr_info("%s: __itcm_start va:0x%08lx size:%d\n",
+			__func__, (unsigned long)&__tcm_start, &__dtcm_start - &__tcm_start);
+
+	memcpy((void *)__fix_to_virt(FIX_TCM - CONFIG_ITCM_NR_PAGES),
+				&__dtcm_start, &__tcm_end - &__dtcm_start);
+
+	pr_info("%s: mapping dtcm va:0x%08lx to pa:0x%08x\n",
+			__func__, __fix_to_virt(FIX_TCM - CONFIG_ITCM_NR_PAGES),
+						CONFIG_DTCM_RAM_BASE);
+
+	pr_info("%s: __dtcm_start va:0x%08lx size:%d\n",
+			__func__, (unsigned long)&__dtcm_start, &__tcm_end - &__dtcm_start);
+
+#endif
+	return;
+panic:
+	panic("TCM init error");
+}
+
+void *tcm_alloc(size_t len)
+{
+	unsigned long vaddr;
+
+	if (!tcm_pool)
+		return NULL;
+
+	vaddr = gen_pool_alloc(tcm_pool, len);
+	if (!vaddr)
+		return NULL;
+
+	return (void *) vaddr;
+}
+EXPORT_SYMBOL(tcm_alloc);
+
+void tcm_free(void *addr, size_t len)
+{
+	gen_pool_free(tcm_pool, (unsigned long) addr, len);
+}
+EXPORT_SYMBOL(tcm_free);
+
+static int __init tcm_setup_pool(void)
+{
+#ifndef CONFIG_HAVE_DTCM
+	u32 pool_size = (u32) (TCM_NR_PAGES * PAGE_SIZE)
+				- (u32) (&__tcm_end - &__tcm_start);
+
+	u32 tcm_pool_start = __fix_to_virt(FIX_TCM)
+				+ (u32) (&__tcm_end - &__tcm_start);
+#else
+	u32 pool_size = (u32) (CONFIG_DTCM_NR_PAGES * PAGE_SIZE)
+				- (u32) (&__tcm_end - &__dtcm_start);
+
+	u32 tcm_pool_start = __fix_to_virt(FIX_TCM - CONFIG_ITCM_NR_PAGES)
+				+ (u32) (&__tcm_end - &__dtcm_start);
+#endif
+	int ret;
+
+	tcm_pool = gen_pool_create(2, -1);
+
+	ret = gen_pool_add(tcm_pool, tcm_pool_start, pool_size, -1);
+	if (ret) {
+		pr_err("%s: gen_pool add failed!\n", __func__);
+		return ret;
+	}
+
+	pr_info("%s: Added %d bytes @ 0x%08x to memory pool\n",
+		__func__, pool_size, tcm_pool_start);
+
+	return 0;
+}
+
+static int __init tcm_init(void)
+{
+	tcm_mapping_init();
+
+	tcm_setup_pool();
+
+	return 0;
+}
+arch_initcall(tcm_init);
diff --git a/arch/csky/mm/tlb.c b/arch/csky/mm/tlb.c
new file mode 100644
index 000000000..ed1512381
--- /dev/null
+++ b/arch/csky/mm/tlb.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+
+#include <asm/mmu_context.h>
+#include <asm/setup.h>
+
+/*
+ * One C-SKY MMU TLB entry contain two PFN/page entry, ie:
+ * 1VPN -> 2PFN
+ */
+#define TLB_ENTRY_SIZE		(PAGE_SIZE * 2)
+#define TLB_ENTRY_SIZE_MASK	(PAGE_MASK << 1)
+
+void flush_tlb_all(void)
+{
+	tlb_invalid_all();
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+#ifdef CONFIG_CPU_HAS_TLBI
+	asm volatile("tlbi.asids %0"::"r"(cpu_asid(mm)));
+#else
+	tlb_invalid_all();
+#endif
+}
+
+/*
+ * MMU operation regs only could invalid tlb entry in jtlb and we
+ * need change asid field to invalid I-utlb & D-utlb.
+ */
+#ifndef CONFIG_CPU_HAS_TLBI
+#define restore_asid_inv_utlb(oldpid, newpid) \
+do { \
+	if (oldpid == newpid) \
+		write_mmu_entryhi(oldpid + 1); \
+	write_mmu_entryhi(oldpid); \
+} while (0)
+#endif
+
+void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+			unsigned long end)
+{
+	unsigned long newpid = cpu_asid(vma->vm_mm);
+
+	start &= TLB_ENTRY_SIZE_MASK;
+	end   += TLB_ENTRY_SIZE - 1;
+	end   &= TLB_ENTRY_SIZE_MASK;
+
+#ifdef CONFIG_CPU_HAS_TLBI
+	while (start < end) {
+		asm volatile("tlbi.vas %0"::"r"(start | newpid));
+		start += 2*PAGE_SIZE;
+	}
+	sync_is();
+#else
+	{
+	unsigned long flags, oldpid;
+
+	local_irq_save(flags);
+	oldpid = read_mmu_entryhi() & ASID_MASK;
+	while (start < end) {
+		int idx;
+
+		write_mmu_entryhi(start | newpid);
+		start += 2*PAGE_SIZE;
+		tlb_probe();
+		idx = read_mmu_index();
+		if (idx >= 0)
+			tlb_invalid_indexed();
+	}
+	restore_asid_inv_utlb(oldpid, newpid);
+	local_irq_restore(flags);
+	}
+#endif
+}
+
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+	start &= TLB_ENTRY_SIZE_MASK;
+	end   += TLB_ENTRY_SIZE - 1;
+	end   &= TLB_ENTRY_SIZE_MASK;
+
+#ifdef CONFIG_CPU_HAS_TLBI
+	while (start < end) {
+		asm volatile("tlbi.vaas %0"::"r"(start));
+		start += 2*PAGE_SIZE;
+	}
+	sync_is();
+#else
+	{
+	unsigned long flags, oldpid;
+
+	local_irq_save(flags);
+	oldpid = read_mmu_entryhi() & ASID_MASK;
+	while (start < end) {
+		int idx;
+
+		write_mmu_entryhi(start | oldpid);
+		start += 2*PAGE_SIZE;
+		tlb_probe();
+		idx = read_mmu_index();
+		if (idx >= 0)
+			tlb_invalid_indexed();
+	}
+	restore_asid_inv_utlb(oldpid, oldpid);
+	local_irq_restore(flags);
+	}
+#endif
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
+{
+	int newpid = cpu_asid(vma->vm_mm);
+
+	addr &= TLB_ENTRY_SIZE_MASK;
+
+#ifdef CONFIG_CPU_HAS_TLBI
+	asm volatile("tlbi.vas %0"::"r"(addr | newpid));
+	sync_is();
+#else
+	{
+	int oldpid, idx;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	oldpid = read_mmu_entryhi() & ASID_MASK;
+	write_mmu_entryhi(addr | newpid);
+	tlb_probe();
+	idx = read_mmu_index();
+	if (idx >= 0)
+		tlb_invalid_indexed();
+
+	restore_asid_inv_utlb(oldpid, newpid);
+	local_irq_restore(flags);
+	}
+#endif
+}
+
+void flush_tlb_one(unsigned long addr)
+{
+	addr &= TLB_ENTRY_SIZE_MASK;
+
+#ifdef CONFIG_CPU_HAS_TLBI
+	asm volatile("tlbi.vaas %0"::"r"(addr));
+	sync_is();
+#else
+	{
+	int oldpid, idx;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	oldpid = read_mmu_entryhi() & ASID_MASK;
+	write_mmu_entryhi(addr | oldpid);
+	tlb_probe();
+	idx = read_mmu_index();
+	if (idx >= 0)
+		tlb_invalid_indexed();
+
+	restore_asid_inv_utlb(oldpid, oldpid);
+	local_irq_restore(flags);
+	}
+#endif
+}
+EXPORT_SYMBOL(flush_tlb_one);