Adding upstream version 5.10.209.upstream/5.10.209upstream

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

11 files changed, 2222 insertions, 0 deletions

diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile
new file mode 100644
index 000000000..678333936
--- /dev/null
+++ b/arch/s390/lib/Makefile
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for s390-specific library files..
+#
+
+lib-y += delay.o string.o uaccess.o find.o spinlock.o
+obj-y += mem.o xor.o
+lib-$(CONFIG_KPROBES) += probes.o
+lib-$(CONFIG_UPROBES) += probes.o
+
+# Instrumenting memory accesses to __user data (in different address space)
+# produce false positives
+KASAN_SANITIZE_uaccess.o := n
+
+obj-$(CONFIG_S390_UNWIND_SELFTEST) += test_unwind.o
+CFLAGS_test_unwind.o += -fno-optimize-sibling-calls
+
+lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c
new file mode 100644
index 000000000..8c0c68e77
--- /dev/null
+++ b/arch/s390/lib/delay.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    Precise Delay Loops for S390
+ *
+ *    Copyright IBM Corp. 1999, 2008
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
+ */
+
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/timex.h>
+#include <linux/export.h>
+#include <linux/irqflags.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <asm/vtimer.h>
+#include <asm/div64.h>
+#include <asm/idle.h>
+
+void __delay(unsigned long loops)
+{
+        /*
+         * To end the bloody studid and useless discussion about the
+         * BogoMips number I took the liberty to define the __delay
+         * function in a way that that resulting BogoMips number will
+         * yield the megahertz number of the cpu. The important function
+         * is udelay and that is done using the tod clock. -- martin.
+         */
+	asm volatile("0: brct %0,0b" : : "d" ((loops/2) + 1));
+}
+EXPORT_SYMBOL(__delay);
+
+static void __udelay_disabled(unsigned long long usecs)
+{
+	unsigned long cr0, cr0_new, psw_mask;
+	struct s390_idle_data idle;
+	u64 end;
+
+	end = get_tod_clock() + (usecs << 12);
+	__ctl_store(cr0, 0, 0);
+	cr0_new = cr0 & ~CR0_IRQ_SUBCLASS_MASK;
+	cr0_new |= (1UL << (63 - 52)); /* enable clock comparator irq */
+	__ctl_load(cr0_new, 0, 0);
+	psw_mask = __extract_psw() | PSW_MASK_EXT | PSW_MASK_WAIT;
+	set_clock_comparator(end);
+	set_cpu_flag(CIF_IGNORE_IRQ);
+	psw_idle(&idle, psw_mask);
+	trace_hardirqs_off();
+	clear_cpu_flag(CIF_IGNORE_IRQ);
+	set_clock_comparator(S390_lowcore.clock_comparator);
+	__ctl_load(cr0, 0, 0);
+}
+
+static void __udelay_enabled(unsigned long long usecs)
+{
+	u64 clock_saved, end;
+
+	end = get_tod_clock_fast() + (usecs << 12);
+	do {
+		clock_saved = 0;
+		if (tod_after(S390_lowcore.clock_comparator, end)) {
+			clock_saved = local_tick_disable();
+			set_clock_comparator(end);
+		}
+		enabled_wait();
+		if (clock_saved)
+			local_tick_enable(clock_saved);
+	} while (get_tod_clock_fast() < end);
+}
+
+/*
+ * Waits for 'usecs' microseconds using the TOD clock comparator.
+ */
+void __udelay(unsigned long long usecs)
+{
+	unsigned long flags;
+
+	preempt_disable();
+	local_irq_save(flags);
+	if (in_irq()) {
+		__udelay_disabled(usecs);
+		goto out;
+	}
+	if (in_softirq()) {
+		if (raw_irqs_disabled_flags(flags))
+			__udelay_disabled(usecs);
+		else
+			__udelay_enabled(usecs);
+		goto out;
+	}
+	if (raw_irqs_disabled_flags(flags)) {
+		local_bh_disable();
+		__udelay_disabled(usecs);
+		_local_bh_enable();
+		goto out;
+	}
+	__udelay_enabled(usecs);
+out:
+	local_irq_restore(flags);
+	preempt_enable();
+}
+EXPORT_SYMBOL(__udelay);
+
+/*
+ * Simple udelay variant. To be used on startup and reboot
+ * when the interrupt handler isn't working.
+ */
+void udelay_simple(unsigned long long usecs)
+{
+	u64 end;
+
+	end = get_tod_clock_fast() + (usecs << 12);
+	while (get_tod_clock_fast() < end)
+		cpu_relax();
+}
+
+void __ndelay(unsigned long long nsecs)
+{
+	u64 end;
+
+	nsecs <<= 9;
+	do_div(nsecs, 125);
+	end = get_tod_clock_fast() + nsecs;
+	if (nsecs & ~0xfffUL)
+		__udelay(nsecs >> 12);
+	while (get_tod_clock_fast() < end)
+		barrier();
+}
+EXPORT_SYMBOL(__ndelay);
diff --git a/arch/s390/lib/error-inject.c b/arch/s390/lib/error-inject.c
new file mode 100644
index 000000000..8c9d4da87
--- /dev/null
+++ b/arch/s390/lib/error-inject.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <asm/ptrace.h>
+#include <linux/error-injection.h>
+#include <linux/kprobes.h>
+
+void override_function_with_return(struct pt_regs *regs)
+{
+	/*
+	 * Emulate 'br 14'. 'regs' is captured by kprobes on entry to some
+	 * kernel function.
+	 */
+	regs->psw.addr = regs->gprs[14];
+}
+NOKPROBE_SYMBOL(override_function_with_return);
diff --git a/arch/s390/lib/find.c b/arch/s390/lib/find.c
new file mode 100644
index 000000000..96a8a2e2d
--- /dev/null
+++ b/arch/s390/lib/find.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MSB0 numbered special bitops handling.
+ *
+ * The bits are numbered:
+ *   |0..............63|64............127|128...........191|192...........255|
+ *
+ * The reason for this bit numbering is the fact that the hardware sets bits
+ * in a bitmap starting at bit 0 (MSB) and we don't want to scan the bitmap
+ * from the 'wrong end'.
+ */
+
+#include <linux/compiler.h>
+#include <linux/bitops.h>
+#include <linux/export.h>
+
+unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size)
+{
+	const unsigned long *p = addr;
+	unsigned long result = 0;
+	unsigned long tmp;
+
+	while (size & ~(BITS_PER_LONG - 1)) {
+		if ((tmp = *(p++)))
+			goto found;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+	tmp = (*p) & (~0UL << (BITS_PER_LONG - size));
+	if (!tmp)		/* Are any bits set? */
+		return result + size;	/* Nope. */
+found:
+	return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
+}
+EXPORT_SYMBOL(find_first_bit_inv);
+
+unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
+				unsigned long offset)
+{
+	const unsigned long *p = addr + (offset / BITS_PER_LONG);
+	unsigned long result = offset & ~(BITS_PER_LONG - 1);
+	unsigned long tmp;
+
+	if (offset >= size)
+		return size;
+	size -= result;
+	offset %= BITS_PER_LONG;
+	if (offset) {
+		tmp = *(p++);
+		tmp &= (~0UL >> offset);
+		if (size < BITS_PER_LONG)
+			goto found_first;
+		if (tmp)
+			goto found_middle;
+		size -= BITS_PER_LONG;
+		result += BITS_PER_LONG;
+	}
+	while (size & ~(BITS_PER_LONG-1)) {
+		if ((tmp = *(p++)))
+			goto found_middle;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+	tmp = *p;
+found_first:
+	tmp &= (~0UL << (BITS_PER_LONG - size));
+	if (!tmp)		/* Are any bits set? */
+		return result + size;	/* Nope. */
+found_middle:
+	return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
+}
+EXPORT_SYMBOL(find_next_bit_inv);
diff --git a/arch/s390/lib/mem.S b/arch/s390/lib/mem.S
new file mode 100644
index 000000000..dc0874f2e
--- /dev/null
+++ b/arch/s390/lib/mem.S
@@ -0,0 +1,191 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * String handling functions.
+ *
+ * Copyright IBM Corp. 2012
+ */
+
+#include <linux/linkage.h>
+#include <asm/export.h>
+#include <asm/nospec-insn.h>
+
+	GEN_BR_THUNK %r14
+
+/*
+ * void *memmove(void *dest, const void *src, size_t n)
+ */
+WEAK(memmove)
+ENTRY(__memmove)
+	ltgr	%r4,%r4
+	lgr	%r1,%r2
+	jz	.Lmemmove_exit
+	aghi	%r4,-1
+	clgr	%r2,%r3
+	jnh	.Lmemmove_forward
+	la	%r5,1(%r4,%r3)
+	clgr	%r2,%r5
+	jl	.Lmemmove_reverse
+.Lmemmove_forward:
+	srlg	%r0,%r4,8
+	ltgr	%r0,%r0
+	jz	.Lmemmove_forward_remainder
+.Lmemmove_forward_loop:
+	mvc	0(256,%r1),0(%r3)
+	la	%r1,256(%r1)
+	la	%r3,256(%r3)
+	brctg	%r0,.Lmemmove_forward_loop
+.Lmemmove_forward_remainder:
+	larl	%r5,.Lmemmove_mvc
+	ex	%r4,0(%r5)
+.Lmemmove_exit:
+	BR_EX	%r14
+.Lmemmove_reverse:
+	ic	%r0,0(%r4,%r3)
+	stc	%r0,0(%r4,%r1)
+	brctg	%r4,.Lmemmove_reverse
+	ic	%r0,0(%r4,%r3)
+	stc	%r0,0(%r4,%r1)
+	BR_EX	%r14
+.Lmemmove_mvc:
+	mvc	0(1,%r1),0(%r3)
+ENDPROC(__memmove)
+EXPORT_SYMBOL(memmove)
+
+/*
+ * memset implementation
+ *
+ * This code corresponds to the C construct below. We do distinguish
+ * between clearing (c == 0) and setting a memory array (c != 0) simply
+ * because nearly all memset invocations in the kernel clear memory and
+ * the xc instruction is preferred in such cases.
+ *
+ * void *memset(void *s, int c, size_t n)
+ * {
+ *	if (likely(c == 0))
+ *		return __builtin_memset(s, 0, n);
+ *	return __builtin_memset(s, c, n);
+ * }
+ */
+WEAK(memset)
+ENTRY(__memset)
+	ltgr	%r4,%r4
+	jz	.Lmemset_exit
+	ltgr	%r3,%r3
+	jnz	.Lmemset_fill
+	aghi	%r4,-1
+	srlg	%r3,%r4,8
+	ltgr	%r3,%r3
+	lgr	%r1,%r2
+	jz	.Lmemset_clear_remainder
+.Lmemset_clear_loop:
+	xc	0(256,%r1),0(%r1)
+	la	%r1,256(%r1)
+	brctg	%r3,.Lmemset_clear_loop
+.Lmemset_clear_remainder:
+	larl	%r3,.Lmemset_xc
+	ex	%r4,0(%r3)
+.Lmemset_exit:
+	BR_EX	%r14
+.Lmemset_fill:
+	cghi	%r4,1
+	lgr	%r1,%r2
+	je	.Lmemset_fill_exit
+	aghi	%r4,-2
+	srlg	%r5,%r4,8
+	ltgr	%r5,%r5
+	jz	.Lmemset_fill_remainder
+.Lmemset_fill_loop:
+	stc	%r3,0(%r1)
+	mvc	1(255,%r1),0(%r1)
+	la	%r1,256(%r1)
+	brctg	%r5,.Lmemset_fill_loop
+.Lmemset_fill_remainder:
+	stc	%r3,0(%r1)
+	larl	%r5,.Lmemset_mvc
+	ex	%r4,0(%r5)
+	BR_EX	%r14
+.Lmemset_fill_exit:
+	stc	%r3,0(%r1)
+	BR_EX	%r14
+.Lmemset_xc:
+	xc	0(1,%r1),0(%r1)
+.Lmemset_mvc:
+	mvc	1(1,%r1),0(%r1)
+ENDPROC(__memset)
+EXPORT_SYMBOL(memset)
+
+/*
+ * memcpy implementation
+ *
+ * void *memcpy(void *dest, const void *src, size_t n)
+ */
+WEAK(memcpy)
+ENTRY(__memcpy)
+	ltgr	%r4,%r4
+	jz	.Lmemcpy_exit
+	aghi	%r4,-1
+	srlg	%r5,%r4,8
+	ltgr	%r5,%r5
+	lgr	%r1,%r2
+	jnz	.Lmemcpy_loop
+.Lmemcpy_remainder:
+	larl	%r5,.Lmemcpy_mvc
+	ex	%r4,0(%r5)
+.Lmemcpy_exit:
+	BR_EX	%r14
+.Lmemcpy_loop:
+	mvc	0(256,%r1),0(%r3)
+	la	%r1,256(%r1)
+	la	%r3,256(%r3)
+	brctg	%r5,.Lmemcpy_loop
+	j	.Lmemcpy_remainder
+.Lmemcpy_mvc:
+	mvc	0(1,%r1),0(%r3)
+ENDPROC(__memcpy)
+EXPORT_SYMBOL(memcpy)
+
+/*
+ * __memset16/32/64
+ *
+ * void *__memset16(uint16_t *s, uint16_t v, size_t count)
+ * void *__memset32(uint32_t *s, uint32_t v, size_t count)
+ * void *__memset64(uint64_t *s, uint64_t v, size_t count)
+ */
+.macro __MEMSET bits,bytes,insn
+ENTRY(__memset\bits)
+	ltgr	%r4,%r4
+	jz	.L__memset_exit\bits
+	cghi	%r4,\bytes
+	je	.L__memset_store\bits
+	aghi	%r4,-(\bytes+1)
+	srlg	%r5,%r4,8
+	ltgr	%r5,%r5
+	lgr	%r1,%r2
+	jz	.L__memset_remainder\bits
+.L__memset_loop\bits:
+	\insn	%r3,0(%r1)
+	mvc	\bytes(256-\bytes,%r1),0(%r1)
+	la	%r1,256(%r1)
+	brctg	%r5,.L__memset_loop\bits
+.L__memset_remainder\bits:
+	\insn	%r3,0(%r1)
+	larl	%r5,.L__memset_mvc\bits
+	ex	%r4,0(%r5)
+	BR_EX	%r14
+.L__memset_store\bits:
+	\insn	%r3,0(%r2)
+.L__memset_exit\bits:
+	BR_EX	%r14
+.L__memset_mvc\bits:
+	mvc	\bytes(1,%r1),0(%r1)
+ENDPROC(__memset\bits)
+.endm
+
+__MEMSET 16,2,sth
+EXPORT_SYMBOL(__memset16)
+
+__MEMSET 32,4,st
+EXPORT_SYMBOL(__memset32)
+
+__MEMSET 64,8,stg
+EXPORT_SYMBOL(__memset64)
diff --git a/arch/s390/lib/probes.c b/arch/s390/lib/probes.c
new file mode 100644
index 000000000..1e184a034
--- /dev/null
+++ b/arch/s390/lib/probes.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    Common helper functions for kprobes and uprobes
+ *
+ *    Copyright IBM Corp. 2014
+ */
+
+#include <linux/errno.h>
+#include <asm/kprobes.h>
+#include <asm/dis.h>
+
+int probe_is_prohibited_opcode(u16 *insn)
+{
+	if (!is_known_insn((unsigned char *)insn))
+		return -EINVAL;
+	switch (insn[0] >> 8) {
+	case 0x0c:	/* bassm */
+	case 0x0b:	/* bsm	 */
+	case 0x83:	/* diag  */
+	case 0x44:	/* ex	 */
+	case 0xac:	/* stnsm */
+	case 0xad:	/* stosm */
+		return -EINVAL;
+	case 0xc6:
+		switch (insn[0] & 0x0f) {
+		case 0x00: /* exrl   */
+			return -EINVAL;
+		}
+	}
+	switch (insn[0]) {
+	case 0x0101:	/* pr	 */
+	case 0xb25a:	/* bsa	 */
+	case 0xb240:	/* bakr  */
+	case 0xb258:	/* bsg	 */
+	case 0xb218:	/* pc	 */
+	case 0xb228:	/* pt	 */
+	case 0xb98d:	/* epsw	 */
+	case 0xe560:	/* tbegin */
+	case 0xe561:	/* tbeginc */
+	case 0xb2f8:	/* tend	 */
+		return -EINVAL;
+	}
+	return 0;
+}
+
+int probe_get_fixup_type(u16 *insn)
+{
+	/* default fixup method */
+	int fixup = FIXUP_PSW_NORMAL;
+
+	switch (insn[0] >> 8) {
+	case 0x05:	/* balr	*/
+	case 0x0d:	/* basr */
+		fixup = FIXUP_RETURN_REGISTER;
+		/* if r2 = 0, no branch will be taken */
+		if ((insn[0] & 0x0f) == 0)
+			fixup |= FIXUP_BRANCH_NOT_TAKEN;
+		break;
+	case 0x06:	/* bctr	*/
+	case 0x07:	/* bcr	*/
+		fixup = FIXUP_BRANCH_NOT_TAKEN;
+		break;
+	case 0x45:	/* bal	*/
+	case 0x4d:	/* bas	*/
+		fixup = FIXUP_RETURN_REGISTER;
+		break;
+	case 0x47:	/* bc	*/
+	case 0x46:	/* bct	*/
+	case 0x86:	/* bxh	*/
+	case 0x87:	/* bxle	*/
+		fixup = FIXUP_BRANCH_NOT_TAKEN;
+		break;
+	case 0x82:	/* lpsw	*/
+		fixup = FIXUP_NOT_REQUIRED;
+		break;
+	case 0xb2:	/* lpswe */
+		if ((insn[0] & 0xff) == 0xb2)
+			fixup = FIXUP_NOT_REQUIRED;
+		break;
+	case 0xa7:	/* bras	*/
+		if ((insn[0] & 0x0f) == 0x05)
+			fixup |= FIXUP_RETURN_REGISTER;
+		break;
+	case 0xc0:
+		if ((insn[0] & 0x0f) == 0x05)	/* brasl */
+			fixup |= FIXUP_RETURN_REGISTER;
+		break;
+	case 0xeb:
+		switch (insn[2] & 0xff) {
+		case 0x44: /* bxhg  */
+		case 0x45: /* bxleg */
+			fixup = FIXUP_BRANCH_NOT_TAKEN;
+			break;
+		}
+		break;
+	case 0xe3:	/* bctg	*/
+		if ((insn[2] & 0xff) == 0x46)
+			fixup = FIXUP_BRANCH_NOT_TAKEN;
+		break;
+	case 0xec:
+		switch (insn[2] & 0xff) {
+		case 0xe5: /* clgrb */
+		case 0xe6: /* cgrb  */
+		case 0xf6: /* crb   */
+		case 0xf7: /* clrb  */
+		case 0xfc: /* cgib  */
+		case 0xfd: /* cglib */
+		case 0xfe: /* cib   */
+		case 0xff: /* clib  */
+			fixup = FIXUP_BRANCH_NOT_TAKEN;
+			break;
+		}
+		break;
+	}
+	return fixup;
+}
+
+int probe_is_insn_relative_long(u16 *insn)
+{
+	/* Check if we have a RIL-b or RIL-c format instruction which
+	 * we need to modify in order to avoid instruction emulation. */
+	switch (insn[0] >> 8) {
+	case 0xc0:
+		if ((insn[0] & 0x0f) == 0x00) /* larl */
+			return true;
+		break;
+	case 0xc4:
+		switch (insn[0] & 0x0f) {
+		case 0x02: /* llhrl  */
+		case 0x04: /* lghrl  */
+		case 0x05: /* lhrl   */
+		case 0x06: /* llghrl */
+		case 0x07: /* sthrl  */
+		case 0x08: /* lgrl   */
+		case 0x0b: /* stgrl  */
+		case 0x0c: /* lgfrl  */
+		case 0x0d: /* lrl    */
+		case 0x0e: /* llgfrl */
+		case 0x0f: /* strl   */
+			return true;
+		}
+		break;
+	case 0xc6:
+		switch (insn[0] & 0x0f) {
+		case 0x02: /* pfdrl  */
+		case 0x04: /* cghrl  */
+		case 0x05: /* chrl   */
+		case 0x06: /* clghrl */
+		case 0x07: /* clhrl  */
+		case 0x08: /* cgrl   */
+		case 0x0a: /* clgrl  */
+		case 0x0c: /* cgfrl  */
+		case 0x0d: /* crl    */
+		case 0x0e: /* clgfrl */
+		case 0x0f: /* clrl   */
+			return true;
+		}
+		break;
+	}
+	return false;
+}
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
new file mode 100644
index 000000000..9b2dab5a6
--- /dev/null
+++ b/arch/s390/lib/spinlock.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    Out of line spinlock code.
+ *
+ *    Copyright IBM Corp. 2004, 2006
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/spinlock.h>
+#include <linux/jiffies.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/percpu.h>
+#include <asm/alternative.h>
+#include <asm/io.h>
+
+int spin_retry = -1;
+
+static int __init spin_retry_init(void)
+{
+	if (spin_retry < 0)
+		spin_retry = 1000;
+	return 0;
+}
+early_initcall(spin_retry_init);
+
+/**
+ * spin_retry= parameter
+ */
+static int __init spin_retry_setup(char *str)
+{
+	spin_retry = simple_strtoul(str, &str, 0);
+	return 1;
+}
+__setup("spin_retry=", spin_retry_setup);
+
+struct spin_wait {
+	struct spin_wait *next, *prev;
+	int node_id;
+} __aligned(32);
+
+static DEFINE_PER_CPU_ALIGNED(struct spin_wait, spin_wait[4]);
+
+#define _Q_LOCK_CPU_OFFSET	0
+#define _Q_LOCK_STEAL_OFFSET	16
+#define _Q_TAIL_IDX_OFFSET	18
+#define _Q_TAIL_CPU_OFFSET	20
+
+#define _Q_LOCK_CPU_MASK	0x0000ffff
+#define _Q_LOCK_STEAL_ADD	0x00010000
+#define _Q_LOCK_STEAL_MASK	0x00030000
+#define _Q_TAIL_IDX_MASK	0x000c0000
+#define _Q_TAIL_CPU_MASK	0xfff00000
+
+#define _Q_LOCK_MASK		(_Q_LOCK_CPU_MASK | _Q_LOCK_STEAL_MASK)
+#define _Q_TAIL_MASK		(_Q_TAIL_IDX_MASK | _Q_TAIL_CPU_MASK)
+
+void arch_spin_lock_setup(int cpu)
+{
+	struct spin_wait *node;
+	int ix;
+
+	node = per_cpu_ptr(&spin_wait[0], cpu);
+	for (ix = 0; ix < 4; ix++, node++) {
+		memset(node, 0, sizeof(*node));
+		node->node_id = ((cpu + 1) << _Q_TAIL_CPU_OFFSET) +
+			(ix << _Q_TAIL_IDX_OFFSET);
+	}
+}
+
+static inline int arch_load_niai4(int *lock)
+{
+	int owner;
+
+	asm_inline volatile(
+		ALTERNATIVE("", ".long 0xb2fa0040", 49)	/* NIAI 4 */
+		"	l	%0,%1\n"
+		: "=d" (owner) : "Q" (*lock) : "memory");
+	return owner;
+}
+
+static inline int arch_cmpxchg_niai8(int *lock, int old, int new)
+{
+	int expected = old;
+
+	asm_inline volatile(
+		ALTERNATIVE("", ".long 0xb2fa0080", 49)	/* NIAI 8 */
+		"	cs	%0,%3,%1\n"
+		: "=d" (old), "=Q" (*lock)
+		: "0" (old), "d" (new), "Q" (*lock)
+		: "cc", "memory");
+	return expected == old;
+}
+
+static inline struct spin_wait *arch_spin_decode_tail(int lock)
+{
+	int ix, cpu;
+
+	ix = (lock & _Q_TAIL_IDX_MASK) >> _Q_TAIL_IDX_OFFSET;
+	cpu = (lock & _Q_TAIL_CPU_MASK) >> _Q_TAIL_CPU_OFFSET;
+	return per_cpu_ptr(&spin_wait[ix], cpu - 1);
+}
+
+static inline int arch_spin_yield_target(int lock, struct spin_wait *node)
+{
+	if (lock & _Q_LOCK_CPU_MASK)
+		return lock & _Q_LOCK_CPU_MASK;
+	if (node == NULL || node->prev == NULL)
+		return 0;	/* 0 -> no target cpu */
+	while (node->prev)
+		node = node->prev;
+	return node->node_id >> _Q_TAIL_CPU_OFFSET;
+}
+
+static inline void arch_spin_lock_queued(arch_spinlock_t *lp)
+{
+	struct spin_wait *node, *next;
+	int lockval, ix, node_id, tail_id, old, new, owner, count;
+
+	ix = S390_lowcore.spinlock_index++;
+	barrier();
+	lockval = SPINLOCK_LOCKVAL;	/* cpu + 1 */
+	node = this_cpu_ptr(&spin_wait[ix]);
+	node->prev = node->next = NULL;
+	node_id = node->node_id;
+
+	/* Enqueue the node for this CPU in the spinlock wait queue */
+	while (1) {
+		old = READ_ONCE(lp->lock);
+		if ((old & _Q_LOCK_CPU_MASK) == 0 &&
+		    (old & _Q_LOCK_STEAL_MASK) != _Q_LOCK_STEAL_MASK) {
+			/*
+			 * The lock is free but there may be waiters.
+			 * With no waiters simply take the lock, if there
+			 * are waiters try to steal the lock. The lock may
+			 * be stolen three times before the next queued
+			 * waiter will get the lock.
+			 */
+			new = (old ? (old + _Q_LOCK_STEAL_ADD) : 0) | lockval;
+			if (__atomic_cmpxchg_bool(&lp->lock, old, new))
+				/* Got the lock */
+				goto out;
+			/* lock passing in progress */
+			continue;
+		}
+		/* Make the node of this CPU the new tail. */
+		new = node_id | (old & _Q_LOCK_MASK);
+		if (__atomic_cmpxchg_bool(&lp->lock, old, new))
+			break;
+	}
+	/* Set the 'next' pointer of the tail node in the queue */
+	tail_id = old & _Q_TAIL_MASK;
+	if (tail_id != 0) {
+		node->prev = arch_spin_decode_tail(tail_id);
+		WRITE_ONCE(node->prev->next, node);
+	}
+
+	/* Pass the virtual CPU to the lock holder if it is not running */
+	owner = arch_spin_yield_target(old, node);
+	if (owner && arch_vcpu_is_preempted(owner - 1))
+		smp_yield_cpu(owner - 1);
+
+	/* Spin on the CPU local node->prev pointer */
+	if (tail_id != 0) {
+		count = spin_retry;
+		while (READ_ONCE(node->prev) != NULL) {
+			if (count-- >= 0)
+				continue;
+			count = spin_retry;
+			/* Query running state of lock holder again. */
+			owner = arch_spin_yield_target(old, node);
+			if (owner && arch_vcpu_is_preempted(owner - 1))
+				smp_yield_cpu(owner - 1);
+		}
+	}
+
+	/* Spin on the lock value in the spinlock_t */
+	count = spin_retry;
+	while (1) {
+		old = READ_ONCE(lp->lock);
+		owner = old & _Q_LOCK_CPU_MASK;
+		if (!owner) {
+			tail_id = old & _Q_TAIL_MASK;
+			new = ((tail_id != node_id) ? tail_id : 0) | lockval;
+			if (__atomic_cmpxchg_bool(&lp->lock, old, new))
+				/* Got the lock */
+				break;
+			continue;
+		}
+		if (count-- >= 0)
+			continue;
+		count = spin_retry;
+		if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(owner - 1))
+			smp_yield_cpu(owner - 1);
+	}
+
+	/* Pass lock_spin job to next CPU in the queue */
+	if (node_id && tail_id != node_id) {
+		/* Wait until the next CPU has set up the 'next' pointer */
+		while ((next = READ_ONCE(node->next)) == NULL)
+			;
+		next->prev = NULL;
+	}
+
+ out:
+	S390_lowcore.spinlock_index--;
+}
+
+static inline void arch_spin_lock_classic(arch_spinlock_t *lp)
+{
+	int lockval, old, new, owner, count;
+
+	lockval = SPINLOCK_LOCKVAL;	/* cpu + 1 */
+
+	/* Pass the virtual CPU to the lock holder if it is not running */
+	owner = arch_spin_yield_target(READ_ONCE(lp->lock), NULL);
+	if (owner && arch_vcpu_is_preempted(owner - 1))
+		smp_yield_cpu(owner - 1);
+
+	count = spin_retry;
+	while (1) {
+		old = arch_load_niai4(&lp->lock);
+		owner = old & _Q_LOCK_CPU_MASK;
+		/* Try to get the lock if it is free. */
+		if (!owner) {
+			new = (old & _Q_TAIL_MASK) | lockval;
+			if (arch_cmpxchg_niai8(&lp->lock, old, new)) {
+				/* Got the lock */
+				return;
+			}
+			continue;
+		}
+		if (count-- >= 0)
+			continue;
+		count = spin_retry;
+		if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(owner - 1))
+			smp_yield_cpu(owner - 1);
+	}
+}
+
+void arch_spin_lock_wait(arch_spinlock_t *lp)
+{
+	if (test_cpu_flag(CIF_DEDICATED_CPU))
+		arch_spin_lock_queued(lp);
+	else
+		arch_spin_lock_classic(lp);
+}
+EXPORT_SYMBOL(arch_spin_lock_wait);
+
+int arch_spin_trylock_retry(arch_spinlock_t *lp)
+{
+	int cpu = SPINLOCK_LOCKVAL;
+	int owner, count;
+
+	for (count = spin_retry; count > 0; count--) {
+		owner = READ_ONCE(lp->lock);
+		/* Try to get the lock if it is free. */
+		if (!owner) {
+			if (__atomic_cmpxchg_bool(&lp->lock, 0, cpu))
+				return 1;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL(arch_spin_trylock_retry);
+
+void arch_read_lock_wait(arch_rwlock_t *rw)
+{
+	if (unlikely(in_interrupt())) {
+		while (READ_ONCE(rw->cnts) & 0x10000)
+			barrier();
+		return;
+	}
+
+	/* Remove this reader again to allow recursive read locking */
+	__atomic_add_const(-1, &rw->cnts);
+	/* Put the reader into the wait queue */
+	arch_spin_lock(&rw->wait);
+	/* Now add this reader to the count value again */
+	__atomic_add_const(1, &rw->cnts);
+	/* Loop until the writer is done */
+	while (READ_ONCE(rw->cnts) & 0x10000)
+		barrier();
+	arch_spin_unlock(&rw->wait);
+}
+EXPORT_SYMBOL(arch_read_lock_wait);
+
+void arch_write_lock_wait(arch_rwlock_t *rw)
+{
+	int old;
+
+	/* Add this CPU to the write waiters */
+	__atomic_add(0x20000, &rw->cnts);
+
+	/* Put the writer into the wait queue */
+	arch_spin_lock(&rw->wait);
+
+	while (1) {
+		old = READ_ONCE(rw->cnts);
+		if ((old & 0x1ffff) == 0 &&
+		    __atomic_cmpxchg_bool(&rw->cnts, old, old | 0x10000))
+			/* Got the lock */
+			break;
+		barrier();
+	}
+
+	arch_spin_unlock(&rw->wait);
+}
+EXPORT_SYMBOL(arch_write_lock_wait);
+
+void arch_spin_relax(arch_spinlock_t *lp)
+{
+	int cpu;
+
+	cpu = READ_ONCE(lp->lock) & _Q_LOCK_CPU_MASK;
+	if (!cpu)
+		return;
+	if (MACHINE_IS_LPAR && !arch_vcpu_is_preempted(cpu - 1))
+		return;
+	smp_yield_cpu(cpu - 1);
+}
+EXPORT_SYMBOL(arch_spin_relax);
diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c
new file mode 100644
index 000000000..db4e539d8
--- /dev/null
+++ b/arch/s390/lib/string.c
@@ -0,0 +1,371 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    Optimized string functions
+ *
+ *  S390 version
+ *    Copyright IBM Corp. 2004
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+
+#define IN_ARCH_STRING_C 1
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/export.h>
+
+/*
+ * Helper functions to find the end of a string
+ */
+static inline char *__strend(const char *s)
+{
+	register unsigned long r0 asm("0") = 0;
+
+	asm volatile ("0: srst  %0,%1\n"
+		      "   jo    0b"
+		      : "+d" (r0), "+a" (s) :  : "cc", "memory");
+	return (char *) r0;
+}
+
+static inline char *__strnend(const char *s, size_t n)
+{
+	register unsigned long r0 asm("0") = 0;
+	const char *p = s + n;
+
+	asm volatile ("0: srst  %0,%1\n"
+		      "   jo    0b"
+		      : "+d" (p), "+a" (s) : "d" (r0) : "cc", "memory");
+	return (char *) p;
+}
+
+/**
+ * strlen - Find the length of a string
+ * @s: The string to be sized
+ *
+ * returns the length of @s
+ */
+#ifdef __HAVE_ARCH_STRLEN
+size_t strlen(const char *s)
+{
+	return __strend(s) - s;
+}
+EXPORT_SYMBOL(strlen);
+#endif
+
+/**
+ * strnlen - Find the length of a length-limited string
+ * @s: The string to be sized
+ * @n: The maximum number of bytes to search
+ *
+ * returns the minimum of the length of @s and @n
+ */
+#ifdef __HAVE_ARCH_STRNLEN
+size_t strnlen(const char *s, size_t n)
+{
+	return __strnend(s, n) - s;
+}
+EXPORT_SYMBOL(strnlen);
+#endif
+
+/**
+ * strcpy - Copy a %NUL terminated string
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ *
+ * returns a pointer to @dest
+ */
+#ifdef __HAVE_ARCH_STRCPY
+char *strcpy(char *dest, const char *src)
+{
+	register int r0 asm("0") = 0;
+	char *ret = dest;
+
+	asm volatile ("0: mvst  %0,%1\n"
+		      "   jo    0b"
+		      : "+&a" (dest), "+&a" (src) : "d" (r0)
+		      : "cc", "memory" );
+	return ret;
+}
+EXPORT_SYMBOL(strcpy);
+#endif
+
+/**
+ * strlcpy - Copy a %NUL terminated string into a sized buffer
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ * @size: size of destination buffer
+ *
+ * Compatible with *BSD: the result is always a valid
+ * NUL-terminated string that fits in the buffer (unless,
+ * of course, the buffer size is zero). It does not pad
+ * out the result like strncpy() does.
+ */
+#ifdef __HAVE_ARCH_STRLCPY
+size_t strlcpy(char *dest, const char *src, size_t size)
+{
+	size_t ret = __strend(src) - src;
+
+	if (size) {
+		size_t len = (ret >= size) ? size-1 : ret;
+		dest[len] = '\0';
+		memcpy(dest, src, len);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(strlcpy);
+#endif
+
+/**
+ * strncpy - Copy a length-limited, %NUL-terminated string
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ * @n: The maximum number of bytes to copy
+ *
+ * The result is not %NUL-terminated if the source exceeds
+ * @n bytes.
+ */
+#ifdef __HAVE_ARCH_STRNCPY
+char *strncpy(char *dest, const char *src, size_t n)
+{
+	size_t len = __strnend(src, n) - src;
+	memset(dest + len, 0, n - len);
+	memcpy(dest, src, len);
+	return dest;
+}
+EXPORT_SYMBOL(strncpy);
+#endif
+
+/**
+ * strcat - Append one %NUL-terminated string to another
+ * @dest: The string to be appended to
+ * @src: The string to append to it
+ *
+ * returns a pointer to @dest
+ */
+#ifdef __HAVE_ARCH_STRCAT
+char *strcat(char *dest, const char *src)
+{
+	register int r0 asm("0") = 0;
+	unsigned long dummy;
+	char *ret = dest;
+
+	asm volatile ("0: srst  %0,%1\n"
+		      "   jo    0b\n"
+		      "1: mvst  %0,%2\n"
+		      "   jo    1b"
+		      : "=&a" (dummy), "+a" (dest), "+a" (src)
+		      : "d" (r0), "0" (0UL) : "cc", "memory" );
+	return ret;
+}
+EXPORT_SYMBOL(strcat);
+#endif
+
+/**
+ * strlcat - Append a length-limited, %NUL-terminated string to another
+ * @dest: The string to be appended to
+ * @src: The string to append to it
+ * @n: The size of the destination buffer.
+ */
+#ifdef __HAVE_ARCH_STRLCAT
+size_t strlcat(char *dest, const char *src, size_t n)
+{
+	size_t dsize = __strend(dest) - dest;
+	size_t len = __strend(src) - src;
+	size_t res = dsize + len;
+
+	if (dsize < n) {
+		dest += dsize;
+		n -= dsize;
+		if (len >= n)
+			len = n - 1;
+		dest[len] = '\0';
+		memcpy(dest, src, len);
+	}
+	return res;
+}
+EXPORT_SYMBOL(strlcat);
+#endif
+
+/**
+ * strncat - Append a length-limited, %NUL-terminated string to another
+ * @dest: The string to be appended to
+ * @src: The string to append to it
+ * @n: The maximum numbers of bytes to copy
+ *
+ * returns a pointer to @dest
+ *
+ * Note that in contrast to strncpy, strncat ensures the result is
+ * terminated.
+ */
+#ifdef __HAVE_ARCH_STRNCAT
+char *strncat(char *dest, const char *src, size_t n)
+{
+	size_t len = __strnend(src, n) - src;
+	char *p = __strend(dest);
+
+	p[len] = '\0';
+	memcpy(p, src, len);
+	return dest;
+}
+EXPORT_SYMBOL(strncat);
+#endif
+
+/**
+ * strcmp - Compare two strings
+ * @s1: One string
+ * @s2: Another string
+ *
+ * returns   0 if @s1 and @s2 are equal,
+ *	   < 0 if @s1 is less than @s2
+ *	   > 0 if @s1 is greater than @s2
+ */
+#ifdef __HAVE_ARCH_STRCMP
+int strcmp(const char *s1, const char *s2)
+{
+	register int r0 asm("0") = 0;
+	int ret = 0;
+
+	asm volatile ("0: clst %2,%3\n"
+		      "   jo   0b\n"
+		      "   je   1f\n"
+		      "   ic   %0,0(%2)\n"
+		      "   ic   %1,0(%3)\n"
+		      "   sr   %0,%1\n"
+		      "1:"
+		      : "+d" (ret), "+d" (r0), "+a" (s1), "+a" (s2)
+		      : : "cc", "memory");
+	return ret;
+}
+EXPORT_SYMBOL(strcmp);
+#endif
+
+/**
+ * strrchr - Find the last occurrence of a character in a string
+ * @s: The string to be searched
+ * @c: The character to search for
+ */
+#ifdef __HAVE_ARCH_STRRCHR
+char *strrchr(const char *s, int c)
+{
+	ssize_t len = __strend(s) - s;
+
+	do {
+		if (s[len] == (char)c)
+			return (char *)s + len;
+	} while (--len >= 0);
+	return NULL;
+}
+EXPORT_SYMBOL(strrchr);
+#endif
+
+static inline int clcle(const char *s1, unsigned long l1,
+			const char *s2, unsigned long l2)
+{
+	register unsigned long r2 asm("2") = (unsigned long) s1;
+	register unsigned long r3 asm("3") = (unsigned long) l1;
+	register unsigned long r4 asm("4") = (unsigned long) s2;
+	register unsigned long r5 asm("5") = (unsigned long) l2;
+	int cc;
+
+	asm volatile ("0: clcle %1,%3,0\n"
+		      "   jo    0b\n"
+		      "   ipm   %0\n"
+		      "   srl   %0,28"
+		      : "=&d" (cc), "+a" (r2), "+a" (r3),
+			"+a" (r4), "+a" (r5) : : "cc", "memory");
+	return cc;
+}
+
+/**
+ * strstr - Find the first substring in a %NUL terminated string
+ * @s1: The string to be searched
+ * @s2: The string to search for
+ */
+#ifdef __HAVE_ARCH_STRSTR
+char *strstr(const char *s1, const char *s2)
+{
+	int l1, l2;
+
+	l2 = __strend(s2) - s2;
+	if (!l2)
+		return (char *) s1;
+	l1 = __strend(s1) - s1;
+	while (l1-- >= l2) {
+		int cc;
+
+		cc = clcle(s1, l2, s2, l2);
+		if (!cc)
+			return (char *) s1;
+		s1++;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(strstr);
+#endif
+
+/**
+ * memchr - Find a character in an area of memory.
+ * @s: The memory area
+ * @c: The byte to search for
+ * @n: The size of the area.
+ *
+ * returns the address of the first occurrence of @c, or %NULL
+ * if @c is not found
+ */
+#ifdef __HAVE_ARCH_MEMCHR
+void *memchr(const void *s, int c, size_t n)
+{
+	register int r0 asm("0") = (char) c;
+	const void *ret = s + n;
+
+	asm volatile ("0: srst  %0,%1\n"
+		      "   jo    0b\n"
+		      "   jl	1f\n"
+		      "   la    %0,0\n"
+		      "1:"
+		      : "+a" (ret), "+&a" (s) : "d" (r0) : "cc", "memory");
+	return (void *) ret;
+}
+EXPORT_SYMBOL(memchr);
+#endif
+
+/**
+ * memcmp - Compare two areas of memory
+ * @s1: One area of memory
+ * @s2: Another area of memory
+ * @n: The size of the area.
+ */
+#ifdef __HAVE_ARCH_MEMCMP
+int memcmp(const void *s1, const void *s2, size_t n)
+{
+	int ret;
+
+	ret = clcle(s1, n, s2, n);
+	if (ret)
+		ret = ret == 1 ? -1 : 1;
+	return ret;
+}
+EXPORT_SYMBOL(memcmp);
+#endif
+
+/**
+ * memscan - Find a character in an area of memory.
+ * @s: The memory area
+ * @c: The byte to search for
+ * @n: The size of the area.
+ *
+ * returns the address of the first occurrence of @c, or 1 byte past
+ * the area if @c is not found
+ */
+#ifdef __HAVE_ARCH_MEMSCAN
+void *memscan(void *s, int c, size_t n)
+{
+	register int r0 asm("0") = (char) c;
+	const void *ret = s + n;
+
+	asm volatile ("0: srst  %0,%1\n"
+		      "   jo    0b\n"
+		      : "+a" (ret), "+&a" (s) : "d" (r0) : "cc", "memory");
+	return (void *) ret;
+}
+EXPORT_SYMBOL(memscan);
+#endif
diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c
new file mode 100644
index 000000000..b0b67e6d1
--- /dev/null
+++ b/arch/s390/lib/test_unwind.c
@@ -0,0 +1,353 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test module for unwind_for_each_frame
+ */
+
+#define pr_fmt(fmt) "test_unwind: " fmt
+#include <asm/unwind.h>
+#include <linux/completion.h>
+#include <linux/kallsyms.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/kprobes.h>
+#include <linux/wait.h>
+#include <asm/irq.h>
+#include <asm/delay.h>
+
+#define BT_BUF_SIZE (PAGE_SIZE * 4)
+
+/*
+ * To avoid printk line limit split backtrace by lines
+ */
+static void print_backtrace(char *bt)
+{
+	char *p;
+
+	while (true) {
+		p = strsep(&bt, "\n");
+		if (!p)
+			break;
+		pr_err("%s\n", p);
+	}
+}
+
+/*
+ * Calls unwind_for_each_frame(task, regs, sp) and verifies that the result
+ * contains unwindme_func2 followed by unwindme_func1.
+ */
+static noinline int test_unwind(struct task_struct *task, struct pt_regs *regs,
+				unsigned long sp)
+{
+	int frame_count, prev_is_func2, seen_func2_func1;
+	const int max_frames = 128;
+	struct unwind_state state;
+	size_t bt_pos = 0;
+	int ret = 0;
+	char *bt;
+
+	bt = kmalloc(BT_BUF_SIZE, GFP_ATOMIC);
+	if (!bt) {
+		pr_err("failed to allocate backtrace buffer\n");
+		return -ENOMEM;
+	}
+	/* Unwind. */
+	frame_count = 0;
+	prev_is_func2 = 0;
+	seen_func2_func1 = 0;
+	unwind_for_each_frame(&state, task, regs, sp) {
+		unsigned long addr = unwind_get_return_address(&state);
+		char sym[KSYM_SYMBOL_LEN];
+
+		if (frame_count++ == max_frames)
+			break;
+		if (state.reliable && !addr) {
+			pr_err("unwind state reliable but addr is 0\n");
+			kfree(bt);
+			return -EINVAL;
+		}
+		sprint_symbol(sym, addr);
+		if (bt_pos < BT_BUF_SIZE) {
+			bt_pos += snprintf(bt + bt_pos, BT_BUF_SIZE - bt_pos,
+					   state.reliable ? " [%-7s%px] %pSR\n" :
+							    "([%-7s%px] %pSR)\n",
+					   stack_type_name(state.stack_info.type),
+					   (void *)state.sp, (void *)state.ip);
+			if (bt_pos >= BT_BUF_SIZE)
+				pr_err("backtrace buffer is too small\n");
+		}
+		frame_count += 1;
+		if (prev_is_func2 && str_has_prefix(sym, "unwindme_func1"))
+			seen_func2_func1 = 1;
+		prev_is_func2 = str_has_prefix(sym, "unwindme_func2");
+	}
+
+	/* Check the results. */
+	if (unwind_error(&state)) {
+		pr_err("unwind error\n");
+		ret = -EINVAL;
+	}
+	if (!seen_func2_func1) {
+		pr_err("unwindme_func2 and unwindme_func1 not found\n");
+		ret = -EINVAL;
+	}
+	if (frame_count == max_frames) {
+		pr_err("Maximum number of frames exceeded\n");
+		ret = -EINVAL;
+	}
+	if (ret)
+		print_backtrace(bt);
+	kfree(bt);
+	return ret;
+}
+
+/* State of the task being unwound. */
+struct unwindme {
+	int flags;
+	int ret;
+	struct task_struct *task;
+	struct completion task_ready;
+	wait_queue_head_t task_wq;
+	unsigned long sp;
+};
+
+static struct unwindme *unwindme;
+
+/* Values of unwindme.flags. */
+#define UWM_DEFAULT		0x0
+#define UWM_THREAD		0x1	/* Unwind a separate task. */
+#define UWM_REGS		0x2	/* Pass regs to test_unwind(). */
+#define UWM_SP			0x4	/* Pass sp to test_unwind(). */
+#define UWM_CALLER		0x8	/* Unwind starting from caller. */
+#define UWM_SWITCH_STACK	0x10	/* Use CALL_ON_STACK. */
+#define UWM_IRQ			0x20	/* Unwind from irq context. */
+#define UWM_PGM			0x40	/* Unwind from program check handler. */
+
+static __always_inline unsigned long get_psw_addr(void)
+{
+	unsigned long psw_addr;
+
+	asm volatile(
+		"basr	%[psw_addr],0\n"
+		: [psw_addr] "=d" (psw_addr));
+	return psw_addr;
+}
+
+#ifdef CONFIG_KPROBES
+static int pgm_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+	struct unwindme *u = unwindme;
+
+	u->ret = test_unwind(NULL, (u->flags & UWM_REGS) ? regs : NULL,
+			     (u->flags & UWM_SP) ? u->sp : 0);
+	return 0;
+}
+#endif
+
+/* This function may or may not appear in the backtrace. */
+static noinline int unwindme_func4(struct unwindme *u)
+{
+	if (!(u->flags & UWM_CALLER))
+		u->sp = current_frame_address();
+	if (u->flags & UWM_THREAD) {
+		complete(&u->task_ready);
+		wait_event(u->task_wq, kthread_should_park());
+		kthread_parkme();
+		return 0;
+#ifdef CONFIG_KPROBES
+	} else if (u->flags & UWM_PGM) {
+		struct kprobe kp;
+		int ret;
+
+		unwindme = u;
+		memset(&kp, 0, sizeof(kp));
+		kp.symbol_name = "do_report_trap";
+		kp.pre_handler = pgm_pre_handler;
+		ret = register_kprobe(&kp);
+		if (ret < 0) {
+			pr_err("register_kprobe failed %d\n", ret);
+			return -EINVAL;
+		}
+
+		/*
+		 * Trigger operation exception; use insn notation to bypass
+		 * llvm's integrated assembler sanity checks.
+		 */
+		asm volatile(
+			"	.insn	e,0x0000\n"	/* illegal opcode */
+			"0:	nopr	%%r7\n"
+			EX_TABLE(0b, 0b)
+			:);
+
+		unregister_kprobe(&kp);
+		unwindme = NULL;
+		return u->ret;
+#endif
+	} else {
+		struct pt_regs regs;
+
+		memset(&regs, 0, sizeof(regs));
+		regs.psw.addr = get_psw_addr();
+		regs.gprs[15] = current_stack_pointer();
+		return test_unwind(NULL,
+				   (u->flags & UWM_REGS) ? &regs : NULL,
+				   (u->flags & UWM_SP) ? u->sp : 0);
+	}
+}
+
+/* This function may or may not appear in the backtrace. */
+static noinline int unwindme_func3(struct unwindme *u)
+{
+	u->sp = current_frame_address();
+	return unwindme_func4(u);
+}
+
+/* This function must appear in the backtrace. */
+static noinline int unwindme_func2(struct unwindme *u)
+{
+	unsigned long flags;
+	int rc;
+
+	if (u->flags & UWM_SWITCH_STACK) {
+		local_irq_save(flags);
+		local_mcck_disable();
+		rc = CALL_ON_STACK(unwindme_func3, S390_lowcore.nodat_stack, 1, u);
+		local_mcck_enable();
+		local_irq_restore(flags);
+		return rc;
+	} else {
+		return unwindme_func3(u);
+	}
+}
+
+/* This function must follow unwindme_func2 in the backtrace. */
+static noinline int unwindme_func1(void *u)
+{
+	return unwindme_func2((struct unwindme *)u);
+}
+
+static void unwindme_irq_handler(struct ext_code ext_code,
+				       unsigned int param32,
+				       unsigned long param64)
+{
+	struct unwindme *u = READ_ONCE(unwindme);
+
+	if (u && u->task == current) {
+		unwindme = NULL;
+		u->task = NULL;
+		u->ret = unwindme_func1(u);
+	}
+}
+
+static int test_unwind_irq(struct unwindme *u)
+{
+	preempt_disable();
+	if (register_external_irq(EXT_IRQ_CLK_COMP, unwindme_irq_handler)) {
+		pr_info("Couldn't register external interrupt handler");
+		return -1;
+	}
+	u->task = current;
+	unwindme = u;
+	udelay(1);
+	unregister_external_irq(EXT_IRQ_CLK_COMP, unwindme_irq_handler);
+	preempt_enable();
+	return u->ret;
+}
+
+/* Spawns a task and passes it to test_unwind(). */
+static int test_unwind_task(struct unwindme *u)
+{
+	struct task_struct *task;
+	int ret;
+
+	/* Initialize thread-related fields. */
+	init_completion(&u->task_ready);
+	init_waitqueue_head(&u->task_wq);
+
+	/*
+	 * Start the task and wait until it reaches unwindme_func4() and sleeps
+	 * in (task_ready, unwind_done] range.
+	 */
+	task = kthread_run(unwindme_func1, u, "%s", __func__);
+	if (IS_ERR(task)) {
+		pr_err("kthread_run() failed\n");
+		return PTR_ERR(task);
+	}
+	/*
+	 * Make sure task reaches unwindme_func4 before parking it,
+	 * we might park it before kthread function has been executed otherwise
+	 */
+	wait_for_completion(&u->task_ready);
+	kthread_park(task);
+	/* Unwind. */
+	ret = test_unwind(task, NULL, (u->flags & UWM_SP) ? u->sp : 0);
+	kthread_stop(task);
+	return ret;
+}
+
+static int test_unwind_flags(int flags)
+{
+	struct unwindme u;
+
+	u.flags = flags;
+	if (u.flags & UWM_THREAD)
+		return test_unwind_task(&u);
+	else if (u.flags & UWM_IRQ)
+		return test_unwind_irq(&u);
+	else
+		return unwindme_func1(&u);
+}
+
+static int test_unwind_init(void)
+{
+	int ret = 0;
+
+#define TEST(flags)							\
+do {									\
+	pr_info("[ RUN      ] " #flags "\n");				\
+	if (!test_unwind_flags((flags))) {				\
+		pr_info("[       OK ] " #flags "\n");			\
+	} else {							\
+		pr_err("[  FAILED  ] " #flags "\n");			\
+		ret = -EINVAL;						\
+	}								\
+} while (0)
+
+	TEST(UWM_DEFAULT);
+	TEST(UWM_SP);
+	TEST(UWM_REGS);
+	TEST(UWM_SWITCH_STACK);
+	TEST(UWM_SP | UWM_REGS);
+	TEST(UWM_CALLER | UWM_SP);
+	TEST(UWM_CALLER | UWM_SP | UWM_REGS);
+	TEST(UWM_CALLER | UWM_SP | UWM_REGS | UWM_SWITCH_STACK);
+	TEST(UWM_THREAD);
+	TEST(UWM_THREAD | UWM_SP);
+	TEST(UWM_THREAD | UWM_CALLER | UWM_SP);
+	TEST(UWM_IRQ);
+	TEST(UWM_IRQ | UWM_SWITCH_STACK);
+	TEST(UWM_IRQ | UWM_SP);
+	TEST(UWM_IRQ | UWM_REGS);
+	TEST(UWM_IRQ | UWM_SP | UWM_REGS);
+	TEST(UWM_IRQ | UWM_CALLER | UWM_SP);
+	TEST(UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS);
+	TEST(UWM_IRQ | UWM_CALLER | UWM_SP | UWM_REGS | UWM_SWITCH_STACK);
+#ifdef CONFIG_KPROBES
+	TEST(UWM_PGM);
+	TEST(UWM_PGM | UWM_SP);
+	TEST(UWM_PGM | UWM_REGS);
+	TEST(UWM_PGM | UWM_SP | UWM_REGS);
+#endif
+#undef TEST
+
+	return ret;
+}
+
+static void test_unwind_exit(void)
+{
+}
+
+module_init(test_unwind_init);
+module_exit(test_unwind_exit);
+MODULE_LICENSE("GPL");
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
new file mode 100644
index 000000000..fcfd78f99
--- /dev/null
+++ b/arch/s390/lib/uaccess.c
@@ -0,0 +1,448 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Standard user space access functions based on mvcp/mvcs and doing
+ *  interesting things in the secondary space mode.
+ *
+ *    Copyright IBM Corp. 2006,2014
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ *		 Gerald Schaefer (gerald.schaefer@de.ibm.com)
+ */
+
+#include <linux/jump_label.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <asm/mmu_context.h>
+#include <asm/facility.h>
+
+#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
+static DEFINE_STATIC_KEY_FALSE(have_mvcos);
+
+static int __init uaccess_init(void)
+{
+	if (test_facility(27))
+		static_branch_enable(&have_mvcos);
+	return 0;
+}
+early_initcall(uaccess_init);
+
+static inline int copy_with_mvcos(void)
+{
+	if (static_branch_likely(&have_mvcos))
+		return 1;
+	return 0;
+}
+#else
+static inline int copy_with_mvcos(void)
+{
+	return 1;
+}
+#endif
+
+void set_fs(mm_segment_t fs)
+{
+	current->thread.mm_segment = fs;
+	if (fs == USER_DS) {
+		__ctl_load(S390_lowcore.user_asce, 1, 1);
+		clear_cpu_flag(CIF_ASCE_PRIMARY);
+	} else {
+		__ctl_load(S390_lowcore.kernel_asce, 1, 1);
+		set_cpu_flag(CIF_ASCE_PRIMARY);
+	}
+	if (fs & 1) {
+		if (fs == USER_DS_SACF)
+			__ctl_load(S390_lowcore.user_asce, 7, 7);
+		else
+			__ctl_load(S390_lowcore.kernel_asce, 7, 7);
+		set_cpu_flag(CIF_ASCE_SECONDARY);
+	}
+}
+EXPORT_SYMBOL(set_fs);
+
+mm_segment_t enable_sacf_uaccess(void)
+{
+	mm_segment_t old_fs;
+	unsigned long asce, cr;
+	unsigned long flags;
+
+	old_fs = current->thread.mm_segment;
+	if (old_fs & 1)
+		return old_fs;
+	/* protect against a concurrent page table upgrade */
+	local_irq_save(flags);
+	current->thread.mm_segment |= 1;
+	asce = S390_lowcore.kernel_asce;
+	if (likely(old_fs == USER_DS)) {
+		__ctl_store(cr, 1, 1);
+		if (cr != S390_lowcore.kernel_asce) {
+			__ctl_load(S390_lowcore.kernel_asce, 1, 1);
+			set_cpu_flag(CIF_ASCE_PRIMARY);
+		}
+		asce = S390_lowcore.user_asce;
+	}
+	__ctl_store(cr, 7, 7);
+	if (cr != asce) {
+		__ctl_load(asce, 7, 7);
+		set_cpu_flag(CIF_ASCE_SECONDARY);
+	}
+	local_irq_restore(flags);
+	return old_fs;
+}
+EXPORT_SYMBOL(enable_sacf_uaccess);
+
+void disable_sacf_uaccess(mm_segment_t old_fs)
+{
+	current->thread.mm_segment = old_fs;
+	if (old_fs == USER_DS && test_facility(27)) {
+		__ctl_load(S390_lowcore.user_asce, 1, 1);
+		clear_cpu_flag(CIF_ASCE_PRIMARY);
+	}
+}
+EXPORT_SYMBOL(disable_sacf_uaccess);
+
+static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
+						 unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0x01UL;
+	unsigned long tmp1, tmp2;
+
+	tmp1 = -4096UL;
+	asm volatile(
+		"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
+		"6: jz    4f\n"
+		"1: algr  %0,%3\n"
+		"   slgr  %1,%3\n"
+		"   slgr  %2,%3\n"
+		"   j     0b\n"
+		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
+		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
+		"   slgr  %4,%1\n"
+		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
+		"   jnh   5f\n"
+		"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
+		"7: slgr  %0,%4\n"
+		"   j     5f\n"
+		"4: slgr  %0,%0\n"
+		"5:\n"
+		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
+		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
+						unsigned long size)
+{
+	unsigned long tmp1, tmp2;
+	mm_segment_t old_fs;
+
+	old_fs = enable_sacf_uaccess();
+	tmp1 = -256UL;
+	asm volatile(
+		"   sacf  0\n"
+		"0: mvcp  0(%0,%2),0(%1),%3\n"
+		"7: jz    5f\n"
+		"1: algr  %0,%3\n"
+		"   la    %1,256(%1)\n"
+		"   la    %2,256(%2)\n"
+		"2: mvcp  0(%0,%2),0(%1),%3\n"
+		"8: jnz   1b\n"
+		"   j     5f\n"
+		"3: la    %4,255(%1)\n"	/* %4 = ptr + 255 */
+		"   lghi  %3,-4096\n"
+		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
+		"   slgr  %4,%1\n"
+		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
+		"   jnh   6f\n"
+		"4: mvcp  0(%4,%2),0(%1),%3\n"
+		"9: slgr  %0,%4\n"
+		"   j     6f\n"
+		"5: slgr  %0,%0\n"
+		"6: sacf  768\n"
+		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
+		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
+		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: : "cc", "memory");
+	disable_sacf_uaccess(old_fs);
+	return size;
+}
+
+unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	if (copy_with_mvcos())
+		return copy_from_user_mvcos(to, from, n);
+	return copy_from_user_mvcp(to, from, n);
+}
+EXPORT_SYMBOL(raw_copy_from_user);
+
+static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
+					       unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0x010000UL;
+	unsigned long tmp1, tmp2;
+
+	tmp1 = -4096UL;
+	asm volatile(
+		"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+		"6: jz    4f\n"
+		"1: algr  %0,%3\n"
+		"   slgr  %1,%3\n"
+		"   slgr  %2,%3\n"
+		"   j     0b\n"
+		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
+		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
+		"   slgr  %4,%1\n"
+		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
+		"   jnh   5f\n"
+		"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
+		"7: slgr  %0,%4\n"
+		"   j     5f\n"
+		"4: slgr  %0,%0\n"
+		"5:\n"
+		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
+		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
+					      unsigned long size)
+{
+	unsigned long tmp1, tmp2;
+	mm_segment_t old_fs;
+
+	old_fs = enable_sacf_uaccess();
+	tmp1 = -256UL;
+	asm volatile(
+		"   sacf  0\n"
+		"0: mvcs  0(%0,%1),0(%2),%3\n"
+		"7: jz    5f\n"
+		"1: algr  %0,%3\n"
+		"   la    %1,256(%1)\n"
+		"   la    %2,256(%2)\n"
+		"2: mvcs  0(%0,%1),0(%2),%3\n"
+		"8: jnz   1b\n"
+		"   j     5f\n"
+		"3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
+		"   lghi  %3,-4096\n"
+		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
+		"   slgr  %4,%1\n"
+		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
+		"   jnh   6f\n"
+		"4: mvcs  0(%4,%1),0(%2),%3\n"
+		"9: slgr  %0,%4\n"
+		"   j     6f\n"
+		"5: slgr  %0,%0\n"
+		"6: sacf  768\n"
+		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
+		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
+		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: : "cc", "memory");
+	disable_sacf_uaccess(old_fs);
+	return size;
+}
+
+unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	if (copy_with_mvcos())
+		return copy_to_user_mvcos(to, from, n);
+	return copy_to_user_mvcs(to, from, n);
+}
+EXPORT_SYMBOL(raw_copy_to_user);
+
+static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
+					       unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0x010001UL;
+	unsigned long tmp1, tmp2;
+
+	tmp1 = -4096UL;
+	/* FIXME: copy with reduced length. */
+	asm volatile(
+		"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+		"   jz	  2f\n"
+		"1: algr  %0,%3\n"
+		"   slgr  %1,%3\n"
+		"   slgr  %2,%3\n"
+		"   j	  0b\n"
+		"2:slgr  %0,%0\n"
+		"3: \n"
+		EX_TABLE(0b,3b)
+		: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
+		: "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
+					     unsigned long size)
+{
+	mm_segment_t old_fs;
+	unsigned long tmp1;
+
+	old_fs = enable_sacf_uaccess();
+	asm volatile(
+		"   sacf  256\n"
+		"   aghi  %0,-1\n"
+		"   jo	  5f\n"
+		"   bras  %3,3f\n"
+		"0: aghi  %0,257\n"
+		"1: mvc	  0(1,%1),0(%2)\n"
+		"   la	  %1,1(%1)\n"
+		"   la	  %2,1(%2)\n"
+		"   aghi  %0,-1\n"
+		"   jnz	  1b\n"
+		"   j	  5f\n"
+		"2: mvc	  0(256,%1),0(%2)\n"
+		"   la	  %1,256(%1)\n"
+		"   la	  %2,256(%2)\n"
+		"3: aghi  %0,-256\n"
+		"   jnm	  2b\n"
+		"4: ex	  %0,1b-0b(%3)\n"
+		"5: slgr  %0,%0\n"
+		"6: sacf  768\n"
+		EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
+		: "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
+		: : "cc", "memory");
+	disable_sacf_uaccess(old_fs);
+	return size;
+}
+
+unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+	if (copy_with_mvcos())
+		return copy_in_user_mvcos(to, from, n);
+	return copy_in_user_mvc(to, from, n);
+}
+EXPORT_SYMBOL(raw_copy_in_user);
+
+static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0x010000UL;
+	unsigned long tmp1, tmp2;
+
+	tmp1 = -4096UL;
+	asm volatile(
+		"0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
+		"   jz	  4f\n"
+		"1: algr  %0,%2\n"
+		"   slgr  %1,%2\n"
+		"   j	  0b\n"
+		"2: la	  %3,4095(%1)\n"/* %4 = to + 4095 */
+		"   nr	  %3,%2\n"	/* %4 = (to + 4095) & -4096 */
+		"   slgr  %3,%1\n"
+		"   clgr  %0,%3\n"	/* copy crosses next page boundary? */
+		"   jnh	  5f\n"
+		"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
+		"   slgr  %0,%3\n"
+		"   j	  5f\n"
+		"4: slgr  %0,%0\n"
+		"5:\n"
+		EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+		: "+&a" (size), "+&a" (to), "+a" (tmp1), "=&a" (tmp2)
+		: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
+{
+	mm_segment_t old_fs;
+	unsigned long tmp1, tmp2;
+
+	old_fs = enable_sacf_uaccess();
+	asm volatile(
+		"   sacf  256\n"
+		"   aghi  %0,-1\n"
+		"   jo    5f\n"
+		"   bras  %3,3f\n"
+		"   xc    0(1,%1),0(%1)\n"
+		"0: aghi  %0,257\n"
+		"   la    %2,255(%1)\n" /* %2 = ptr + 255 */
+		"   srl   %2,12\n"
+		"   sll   %2,12\n"	/* %2 = (ptr + 255) & -4096 */
+		"   slgr  %2,%1\n"
+		"   clgr  %0,%2\n"	/* clear crosses next page boundary? */
+		"   jnh   5f\n"
+		"   aghi  %2,-1\n"
+		"1: ex    %2,0(%3)\n"
+		"   aghi  %2,1\n"
+		"   slgr  %0,%2\n"
+		"   j     5f\n"
+		"2: xc    0(256,%1),0(%1)\n"
+		"   la    %1,256(%1)\n"
+		"3: aghi  %0,-256\n"
+		"   jnm   2b\n"
+		"4: ex    %0,0(%3)\n"
+		"5: slgr  %0,%0\n"
+		"6: sacf  768\n"
+		EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
+		: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
+		: : "cc", "memory");
+	disable_sacf_uaccess(old_fs);
+	return size;
+}
+
+unsigned long __clear_user(void __user *to, unsigned long size)
+{
+	if (copy_with_mvcos())
+			return clear_user_mvcos(to, size);
+	return clear_user_xc(to, size);
+}
+EXPORT_SYMBOL(__clear_user);
+
+static inline unsigned long strnlen_user_srst(const char __user *src,
+					      unsigned long size)
+{
+	register unsigned long reg0 asm("0") = 0;
+	unsigned long tmp1, tmp2;
+
+	asm volatile(
+		"   la    %2,0(%1)\n"
+		"   la    %3,0(%0,%1)\n"
+		"   slgr  %0,%0\n"
+		"   sacf  256\n"
+		"0: srst  %3,%2\n"
+		"   jo    0b\n"
+		"   la    %0,1(%3)\n"	/* strnlen_user results includes \0 */
+		"   slgr  %0,%1\n"
+		"1: sacf  768\n"
+		EX_TABLE(0b,1b)
+		: "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
+		: "d" (reg0) : "cc", "memory");
+	return size;
+}
+
+unsigned long __strnlen_user(const char __user *src, unsigned long size)
+{
+	mm_segment_t old_fs;
+	unsigned long len;
+
+	if (unlikely(!size))
+		return 0;
+	old_fs = enable_sacf_uaccess();
+	len = strnlen_user_srst(src, size);
+	disable_sacf_uaccess(old_fs);
+	return len;
+}
+EXPORT_SYMBOL(__strnlen_user);
+
+long __strncpy_from_user(char *dst, const char __user *src, long size)
+{
+	size_t done, len, offset, len_str;
+
+	if (unlikely(size <= 0))
+		return 0;
+	done = 0;
+	do {
+		offset = (size_t)src & (L1_CACHE_BYTES - 1);
+		len = min(size - done, L1_CACHE_BYTES - offset);
+		if (copy_from_user(dst, src, len))
+			return -EFAULT;
+		len_str = strnlen(dst, len);
+		done += len_str;
+		src += len_str;
+		dst += len_str;
+	} while ((len_str == len) && (done < size));
+	return done;
+}
+EXPORT_SYMBOL(__strncpy_from_user);
diff --git a/arch/s390/lib/xor.c b/arch/s390/lib/xor.c
new file mode 100644
index 000000000..29d9470db
--- /dev/null
+++ b/arch/s390/lib/xor.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Optimized xor_block operation for RAID4/5
+ *
+ * Copyright IBM Corp. 2016
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/raid/xor.h>
+#include <asm/xor.h>
+
+static void xor_xc_2(unsigned long bytes, unsigned long *p1, unsigned long *p2)
+{
+	asm volatile(
+		"	larl	1,2f\n"
+		"	aghi	%0,-1\n"
+		"	jm	3f\n"
+		"	srlg	0,%0,8\n"
+		"	ltgr	0,0\n"
+		"	jz	1f\n"
+		"0:	xc	0(256,%1),0(%2)\n"
+		"	la	%1,256(%1)\n"
+		"	la	%2,256(%2)\n"
+		"	brctg	0,0b\n"
+		"1:	ex	%0,0(1)\n"
+		"	j	3f\n"
+		"2:	xc	0(1,%1),0(%2)\n"
+		"3:\n"
+		: : "d" (bytes), "a" (p1), "a" (p2)
+		: "0", "1", "cc", "memory");
+}
+
+static void xor_xc_3(unsigned long bytes, unsigned long *p1, unsigned long *p2,
+		     unsigned long *p3)
+{
+	asm volatile(
+		"	larl	1,2f\n"
+		"	aghi	%0,-1\n"
+		"	jm	3f\n"
+		"	srlg	0,%0,8\n"
+		"	ltgr	0,0\n"
+		"	jz	1f\n"
+		"0:	xc	0(256,%1),0(%2)\n"
+		"	xc	0(256,%1),0(%3)\n"
+		"	la	%1,256(%1)\n"
+		"	la	%2,256(%2)\n"
+		"	la	%3,256(%3)\n"
+		"	brctg	0,0b\n"
+		"1:	ex	%0,0(1)\n"
+		"	ex	%0,6(1)\n"
+		"	j	3f\n"
+		"2:	xc	0(1,%1),0(%2)\n"
+		"	xc	0(1,%1),0(%3)\n"
+		"3:\n"
+		: "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3)
+		: : "0", "1", "cc", "memory");
+}
+
+static void xor_xc_4(unsigned long bytes, unsigned long *p1, unsigned long *p2,
+		     unsigned long *p3, unsigned long *p4)
+{
+	asm volatile(
+		"	larl	1,2f\n"
+		"	aghi	%0,-1\n"
+		"	jm	3f\n"
+		"	srlg	0,%0,8\n"
+		"	ltgr	0,0\n"
+		"	jz	1f\n"
+		"0:	xc	0(256,%1),0(%2)\n"
+		"	xc	0(256,%1),0(%3)\n"
+		"	xc	0(256,%1),0(%4)\n"
+		"	la	%1,256(%1)\n"
+		"	la	%2,256(%2)\n"
+		"	la	%3,256(%3)\n"
+		"	la	%4,256(%4)\n"
+		"	brctg	0,0b\n"
+		"1:	ex	%0,0(1)\n"
+		"	ex	%0,6(1)\n"
+		"	ex	%0,12(1)\n"
+		"	j	3f\n"
+		"2:	xc	0(1,%1),0(%2)\n"
+		"	xc	0(1,%1),0(%3)\n"
+		"	xc	0(1,%1),0(%4)\n"
+		"3:\n"
+		: "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3), "+a" (p4)
+		: : "0", "1", "cc", "memory");
+}
+
+static void xor_xc_5(unsigned long bytes, unsigned long *p1, unsigned long *p2,
+		     unsigned long *p3, unsigned long *p4, unsigned long *p5)
+{
+	/* Get around a gcc oddity */
+	register unsigned long *reg7 asm ("7") = p5;
+
+	asm volatile(
+		"	larl	1,2f\n"
+		"	aghi	%0,-1\n"
+		"	jm	3f\n"
+		"	srlg	0,%0,8\n"
+		"	ltgr	0,0\n"
+		"	jz	1f\n"
+		"0:	xc	0(256,%1),0(%2)\n"
+		"	xc	0(256,%1),0(%3)\n"
+		"	xc	0(256,%1),0(%4)\n"
+		"	xc	0(256,%1),0(%5)\n"
+		"	la	%1,256(%1)\n"
+		"	la	%2,256(%2)\n"
+		"	la	%3,256(%3)\n"
+		"	la	%4,256(%4)\n"
+		"	la	%5,256(%5)\n"
+		"	brctg	0,0b\n"
+		"1:	ex	%0,0(1)\n"
+		"	ex	%0,6(1)\n"
+		"	ex	%0,12(1)\n"
+		"	ex	%0,18(1)\n"
+		"	j	3f\n"
+		"2:	xc	0(1,%1),0(%2)\n"
+		"	xc	0(1,%1),0(%3)\n"
+		"	xc	0(1,%1),0(%4)\n"
+		"	xc	0(1,%1),0(%5)\n"
+		"3:\n"
+		: "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3), "+a" (p4),
+		  "+a" (reg7)
+		: : "0", "1", "cc", "memory");
+}
+
+struct xor_block_template xor_block_xc = {
+	.name = "xc",
+	.do_2 = xor_xc_2,
+	.do_3 = xor_xc_3,
+	.do_4 = xor_xc_4,
+	.do_5 = xor_xc_5,
+};
+EXPORT_SYMBOL(xor_block_xc);