Adding upstream version 4.19.249.upstream/4.19.249upstream

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

11 files changed, 3796 insertions, 0 deletions

diff --git a/arch/arc/mm/Makefile b/arch/arc/mm/Makefile
new file mode 100644
index 000000000..3703a4969
--- /dev/null
+++ b/arch/arc/mm/Makefile
@@ -0,0 +1,11 @@
+#
+# Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+
+obj-y	:= extable.o ioremap.o dma.o fault.o init.o
+obj-y	+= tlb.o tlbex.o cache.o mmap.o
+obj-$(CONFIG_HIGHMEM)	+= highmem.o
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
new file mode 100644
index 000000000..c5254c596
--- /dev/null
+++ b/arch/arc/mm/cache.c
@@ -0,0 +1,1332 @@
+/*
+ * ARC Cache Management
+ *
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/cache.h>
+#include <linux/mmu_context.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <linux/pagemap.h>
+#include <asm/cacheflush.h>
+#include <asm/cachectl.h>
+#include <asm/setup.h>
+
+#ifdef CONFIG_ISA_ARCV2
+#define USE_RGN_FLSH	1
+#endif
+
+static int l2_line_sz;
+static int ioc_exists;
+int slc_enable = 1, ioc_enable = 1;
+unsigned long perip_base = ARC_UNCACHED_ADDR_SPACE; /* legacy value for boot */
+unsigned long perip_end = 0xFFFFFFFF; /* legacy value */
+
+void (*_cache_line_loop_ic_fn)(phys_addr_t paddr, unsigned long vaddr,
+			       unsigned long sz, const int op, const int full_page);
+
+void (*__dma_cache_wback_inv)(phys_addr_t start, unsigned long sz);
+void (*__dma_cache_inv)(phys_addr_t start, unsigned long sz);
+void (*__dma_cache_wback)(phys_addr_t start, unsigned long sz);
+
+char *arc_cache_mumbojumbo(int c, char *buf, int len)
+{
+	int n = 0;
+	struct cpuinfo_arc_cache *p;
+
+#define PR_CACHE(p, cfg, str)						\
+	if (!(p)->line_len)						\
+		n += scnprintf(buf + n, len - n, str"\t\t: N/A\n");	\
+	else								\
+		n += scnprintf(buf + n, len - n,			\
+			str"\t\t: %uK, %dway/set, %uB Line, %s%s%s\n",	\
+			(p)->sz_k, (p)->assoc, (p)->line_len,		\
+			(p)->vipt ? "VIPT" : "PIPT",			\
+			(p)->alias ? " aliasing" : "",			\
+			IS_USED_CFG(cfg));
+
+	PR_CACHE(&cpuinfo_arc700[c].icache, CONFIG_ARC_HAS_ICACHE, "I-Cache");
+	PR_CACHE(&cpuinfo_arc700[c].dcache, CONFIG_ARC_HAS_DCACHE, "D-Cache");
+
+	p = &cpuinfo_arc700[c].slc;
+	if (p->line_len)
+		n += scnprintf(buf + n, len - n,
+			       "SLC\t\t: %uK, %uB Line%s\n",
+			       p->sz_k, p->line_len, IS_USED_RUN(slc_enable));
+
+	n += scnprintf(buf + n, len - n, "Peripherals\t: %#lx%s%s\n",
+		       perip_base,
+		       IS_AVAIL3(ioc_exists, ioc_enable, ", IO-Coherency (per-device) "));
+
+	return buf;
+}
+
+/*
+ * Read the Cache Build Confuration Registers, Decode them and save into
+ * the cpuinfo structure for later use.
+ * No Validation done here, simply read/convert the BCRs
+ */
+static void read_decode_cache_bcr_arcv2(int cpu)
+{
+	struct cpuinfo_arc_cache *p_slc = &cpuinfo_arc700[cpu].slc;
+	struct bcr_generic sbcr;
+
+	struct bcr_slc_cfg {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		unsigned int pad:24, way:2, lsz:2, sz:4;
+#else
+		unsigned int sz:4, lsz:2, way:2, pad:24;
+#endif
+	} slc_cfg;
+
+	struct bcr_clust_cfg {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		unsigned int pad:7, c:1, num_entries:8, num_cores:8, ver:8;
+#else
+		unsigned int ver:8, num_cores:8, num_entries:8, c:1, pad:7;
+#endif
+	} cbcr;
+
+	struct bcr_volatile {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		unsigned int start:4, limit:4, pad:22, order:1, disable:1;
+#else
+		unsigned int disable:1, order:1, pad:22, limit:4, start:4;
+#endif
+	} vol;
+
+
+	READ_BCR(ARC_REG_SLC_BCR, sbcr);
+	if (sbcr.ver) {
+		READ_BCR(ARC_REG_SLC_CFG, slc_cfg);
+		p_slc->sz_k = 128 << slc_cfg.sz;
+		l2_line_sz = p_slc->line_len = (slc_cfg.lsz == 0) ? 128 : 64;
+	}
+
+	READ_BCR(ARC_REG_CLUSTER_BCR, cbcr);
+	if (cbcr.c)
+		ioc_exists = 1;
+	else
+		ioc_enable = 0;
+
+	/* HS 2.0 didn't have AUX_VOL */
+	if (cpuinfo_arc700[cpu].core.family > 0x51) {
+		READ_BCR(AUX_VOL, vol);
+		perip_base = vol.start << 28;
+		/* HS 3.0 has limit and strict-ordering fields */
+		if (cpuinfo_arc700[cpu].core.family > 0x52)
+			perip_end = (vol.limit << 28) - 1;
+	}
+}
+
+void read_decode_cache_bcr(void)
+{
+	struct cpuinfo_arc_cache *p_ic, *p_dc;
+	unsigned int cpu = smp_processor_id();
+	struct bcr_cache {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		unsigned int pad:12, line_len:4, sz:4, config:4, ver:8;
+#else
+		unsigned int ver:8, config:4, sz:4, line_len:4, pad:12;
+#endif
+	} ibcr, dbcr;
+
+	p_ic = &cpuinfo_arc700[cpu].icache;
+	READ_BCR(ARC_REG_IC_BCR, ibcr);
+
+	if (!ibcr.ver)
+		goto dc_chk;
+
+	if (ibcr.ver <= 3) {
+		BUG_ON(ibcr.config != 3);
+		p_ic->assoc = 2;		/* Fixed to 2w set assoc */
+	} else if (ibcr.ver >= 4) {
+		p_ic->assoc = 1 << ibcr.config;	/* 1,2,4,8 */
+	}
+
+	p_ic->line_len = 8 << ibcr.line_len;
+	p_ic->sz_k = 1 << (ibcr.sz - 1);
+	p_ic->vipt = 1;
+	p_ic->alias = p_ic->sz_k/p_ic->assoc/TO_KB(PAGE_SIZE) > 1;
+
+dc_chk:
+	p_dc = &cpuinfo_arc700[cpu].dcache;
+	READ_BCR(ARC_REG_DC_BCR, dbcr);
+
+	if (!dbcr.ver)
+		goto slc_chk;
+
+	if (dbcr.ver <= 3) {
+		BUG_ON(dbcr.config != 2);
+		p_dc->assoc = 4;		/* Fixed to 4w set assoc */
+		p_dc->vipt = 1;
+		p_dc->alias = p_dc->sz_k/p_dc->assoc/TO_KB(PAGE_SIZE) > 1;
+	} else if (dbcr.ver >= 4) {
+		p_dc->assoc = 1 << dbcr.config;	/* 1,2,4,8 */
+		p_dc->vipt = 0;
+		p_dc->alias = 0;		/* PIPT so can't VIPT alias */
+	}
+
+	p_dc->line_len = 16 << dbcr.line_len;
+	p_dc->sz_k = 1 << (dbcr.sz - 1);
+
+slc_chk:
+	if (is_isa_arcv2())
+                read_decode_cache_bcr_arcv2(cpu);
+}
+
+/*
+ * Line Operation on {I,D}-Cache
+ */
+
+#define OP_INV		0x1
+#define OP_FLUSH	0x2
+#define OP_FLUSH_N_INV	0x3
+#define OP_INV_IC	0x4
+
+/*
+ *		I-Cache Aliasing in ARC700 VIPT caches (MMU v1-v3)
+ *
+ * ARC VIPT I-cache uses vaddr to index into cache and paddr to match the tag.
+ * The orig Cache Management Module "CDU" only required paddr to invalidate a
+ * certain line since it sufficed as index in Non-Aliasing VIPT cache-geometry.
+ * Infact for distinct V1,V2,P: all of {V1-P},{V2-P},{P-P} would end up fetching
+ * the exact same line.
+ *
+ * However for larger Caches (way-size > page-size) - i.e. in Aliasing config,
+ * paddr alone could not be used to correctly index the cache.
+ *
+ * ------------------
+ * MMU v1/v2 (Fixed Page Size 8k)
+ * ------------------
+ * The solution was to provide CDU with these additonal vaddr bits. These
+ * would be bits [x:13], x would depend on cache-geometry, 13 comes from
+ * standard page size of 8k.
+ * H/w folks chose [17:13] to be a future safe range, and moreso these 5 bits
+ * of vaddr could easily be "stuffed" in the paddr as bits [4:0] since the
+ * orig 5 bits of paddr were anyways ignored by CDU line ops, as they
+ * represent the offset within cache-line. The adv of using this "clumsy"
+ * interface for additional info was no new reg was needed in CDU programming
+ * model.
+ *
+ * 17:13 represented the max num of bits passable, actual bits needed were
+ * fewer, based on the num-of-aliases possible.
+ * -for 2 alias possibility, only bit 13 needed (32K cache)
+ * -for 4 alias possibility, bits 14:13 needed (64K cache)
+ *
+ * ------------------
+ * MMU v3
+ * ------------------
+ * This ver of MMU supports variable page sizes (1k-16k): although Linux will
+ * only support 8k (default), 16k and 4k.
+ * However from hardware perspective, smaller page sizes aggravate aliasing
+ * meaning more vaddr bits needed to disambiguate the cache-line-op ;
+ * the existing scheme of piggybacking won't work for certain configurations.
+ * Two new registers IC_PTAG and DC_PTAG inttoduced.
+ * "tag" bits are provided in PTAG, index bits in existing IVIL/IVDL/FLDL regs
+ */
+
+static inline
+void __cache_line_loop_v2(phys_addr_t paddr, unsigned long vaddr,
+			  unsigned long sz, const int op, const int full_page)
+{
+	unsigned int aux_cmd;
+	int num_lines;
+
+	if (op == OP_INV_IC) {
+		aux_cmd = ARC_REG_IC_IVIL;
+	} else {
+		/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
+		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
+	}
+
+	/* Ensure we properly floor/ceil the non-line aligned/sized requests
+	 * and have @paddr - aligned to cache line and integral @num_lines.
+	 * This however can be avoided for page sized since:
+	 *  -@paddr will be cache-line aligned already (being page aligned)
+	 *  -@sz will be integral multiple of line size (being page sized).
+	 */
+	if (!full_page) {
+		sz += paddr & ~CACHE_LINE_MASK;
+		paddr &= CACHE_LINE_MASK;
+		vaddr &= CACHE_LINE_MASK;
+	}
+
+	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
+
+	/* MMUv2 and before: paddr contains stuffed vaddrs bits */
+	paddr |= (vaddr >> PAGE_SHIFT) & 0x1F;
+
+	while (num_lines-- > 0) {
+		write_aux_reg(aux_cmd, paddr);
+		paddr += L1_CACHE_BYTES;
+	}
+}
+
+/*
+ * For ARC700 MMUv3 I-cache and D-cache flushes
+ *  - ARC700 programming model requires paddr and vaddr be passed in seperate
+ *    AUX registers (*_IV*L and *_PTAG respectively) irrespective of whether the
+ *    caches actually alias or not.
+ * -  For HS38, only the aliasing I-cache configuration uses the PTAG reg
+ *    (non aliasing I-cache version doesn't; while D-cache can't possibly alias)
+ */
+static inline
+void __cache_line_loop_v3(phys_addr_t paddr, unsigned long vaddr,
+			  unsigned long sz, const int op, const int full_page)
+{
+	unsigned int aux_cmd, aux_tag;
+	int num_lines;
+
+	if (op == OP_INV_IC) {
+		aux_cmd = ARC_REG_IC_IVIL;
+		aux_tag = ARC_REG_IC_PTAG;
+	} else {
+		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
+		aux_tag = ARC_REG_DC_PTAG;
+	}
+
+	/* Ensure we properly floor/ceil the non-line aligned/sized requests
+	 * and have @paddr - aligned to cache line and integral @num_lines.
+	 * This however can be avoided for page sized since:
+	 *  -@paddr will be cache-line aligned already (being page aligned)
+	 *  -@sz will be integral multiple of line size (being page sized).
+	 */
+	if (!full_page) {
+		sz += paddr & ~CACHE_LINE_MASK;
+		paddr &= CACHE_LINE_MASK;
+		vaddr &= CACHE_LINE_MASK;
+	}
+	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
+
+	/*
+	 * MMUv3, cache ops require paddr in PTAG reg
+	 * if V-P const for loop, PTAG can be written once outside loop
+	 */
+	if (full_page)
+		write_aux_reg(aux_tag, paddr);
+
+	/*
+	 * This is technically for MMU v4, using the MMU v3 programming model
+	 * Special work for HS38 aliasing I-cache configuration with PAE40
+	 *   - upper 8 bits of paddr need to be written into PTAG_HI
+	 *   - (and needs to be written before the lower 32 bits)
+	 * Note that PTAG_HI is hoisted outside the line loop
+	 */
+	if (is_pae40_enabled() && op == OP_INV_IC)
+		write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
+
+	while (num_lines-- > 0) {
+		if (!full_page) {
+			write_aux_reg(aux_tag, paddr);
+			paddr += L1_CACHE_BYTES;
+		}
+
+		write_aux_reg(aux_cmd, vaddr);
+		vaddr += L1_CACHE_BYTES;
+	}
+}
+
+#ifndef USE_RGN_FLSH
+
+/*
+ * In HS38x (MMU v4), I-cache is VIPT (can alias), D-cache is PIPT
+ * Here's how cache ops are implemented
+ *
+ *  - D-cache: only paddr needed (in DC_IVDL/DC_FLDL)
+ *  - I-cache Non Aliasing: Despite VIPT, only paddr needed (in IC_IVIL)
+ *  - I-cache Aliasing: Both vaddr and paddr needed (in IC_IVIL, IC_PTAG
+ *    respectively, similar to MMU v3 programming model, hence
+ *    __cache_line_loop_v3() is used)
+ *
+ * If PAE40 is enabled, independent of aliasing considerations, the higher bits
+ * needs to be written into PTAG_HI
+ */
+static inline
+void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
+			  unsigned long sz, const int op, const int full_page)
+{
+	unsigned int aux_cmd;
+	int num_lines;
+
+	if (op == OP_INV_IC) {
+		aux_cmd = ARC_REG_IC_IVIL;
+	} else {
+		/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
+		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
+	}
+
+	/* Ensure we properly floor/ceil the non-line aligned/sized requests
+	 * and have @paddr - aligned to cache line and integral @num_lines.
+	 * This however can be avoided for page sized since:
+	 *  -@paddr will be cache-line aligned already (being page aligned)
+	 *  -@sz will be integral multiple of line size (being page sized).
+	 */
+	if (!full_page) {
+		sz += paddr & ~CACHE_LINE_MASK;
+		paddr &= CACHE_LINE_MASK;
+	}
+
+	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
+
+	/*
+	 * For HS38 PAE40 configuration
+	 *   - upper 8 bits of paddr need to be written into PTAG_HI
+	 *   - (and needs to be written before the lower 32 bits)
+	 */
+	if (is_pae40_enabled()) {
+		if (op == OP_INV_IC)
+			/*
+			 * Non aliasing I-cache in HS38,
+			 * aliasing I-cache handled in __cache_line_loop_v3()
+			 */
+			write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
+		else
+			write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
+	}
+
+	while (num_lines-- > 0) {
+		write_aux_reg(aux_cmd, paddr);
+		paddr += L1_CACHE_BYTES;
+	}
+}
+
+#else
+
+/*
+ * optimized flush operation which takes a region as opposed to iterating per line
+ */
+static inline
+void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
+			  unsigned long sz, const int op, const int full_page)
+{
+	unsigned int s, e;
+
+	/* Only for Non aliasing I-cache in HS38 */
+	if (op == OP_INV_IC) {
+		s = ARC_REG_IC_IVIR;
+		e = ARC_REG_IC_ENDR;
+	} else {
+		s = ARC_REG_DC_STARTR;
+		e = ARC_REG_DC_ENDR;
+	}
+
+	if (!full_page) {
+		/* for any leading gap between @paddr and start of cache line */
+		sz += paddr & ~CACHE_LINE_MASK;
+		paddr &= CACHE_LINE_MASK;
+
+		/*
+		 *  account for any trailing gap to end of cache line
+		 *  this is equivalent to DIV_ROUND_UP() in line ops above
+		 */
+		sz += L1_CACHE_BYTES - 1;
+	}
+
+	if (is_pae40_enabled()) {
+		/* TBD: check if crossing 4TB boundary */
+		if (op == OP_INV_IC)
+			write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
+		else
+			write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
+	}
+
+	/* ENDR needs to be set ahead of START */
+	write_aux_reg(e, paddr + sz);	/* ENDR is exclusive */
+	write_aux_reg(s, paddr);
+
+	/* caller waits on DC_CTRL.FS */
+}
+
+#endif
+
+#if (CONFIG_ARC_MMU_VER < 3)
+#define __cache_line_loop	__cache_line_loop_v2
+#elif (CONFIG_ARC_MMU_VER == 3)
+#define __cache_line_loop	__cache_line_loop_v3
+#elif (CONFIG_ARC_MMU_VER > 3)
+#define __cache_line_loop	__cache_line_loop_v4
+#endif
+
+#ifdef CONFIG_ARC_HAS_DCACHE
+
+/***************************************************************
+ * Machine specific helpers for Entire D-Cache or Per Line ops
+ */
+
+#ifndef USE_RGN_FLSH
+/*
+ * this version avoids extra read/write of DC_CTRL for flush or invalid ops
+ * in the non region flush regime (such as for ARCompact)
+ */
+static inline void __before_dc_op(const int op)
+{
+	if (op == OP_FLUSH_N_INV) {
+		/* Dcache provides 2 cmd: FLUSH or INV
+		 * INV inturn has sub-modes: DISCARD or FLUSH-BEFORE
+		 * flush-n-inv is achieved by INV cmd but with IM=1
+		 * So toggle INV sub-mode depending on op request and default
+		 */
+		const unsigned int ctl = ARC_REG_DC_CTRL;
+		write_aux_reg(ctl, read_aux_reg(ctl) | DC_CTRL_INV_MODE_FLUSH);
+	}
+}
+
+#else
+
+static inline void __before_dc_op(const int op)
+{
+	const unsigned int ctl = ARC_REG_DC_CTRL;
+	unsigned int val = read_aux_reg(ctl);
+
+	if (op == OP_FLUSH_N_INV) {
+		val |= DC_CTRL_INV_MODE_FLUSH;
+	}
+
+	if (op != OP_INV_IC) {
+		/*
+		 * Flush / Invalidate is provided by DC_CTRL.RNG_OP 0 or 1
+		 * combined Flush-n-invalidate uses DC_CTRL.IM = 1 set above
+		 */
+		val &= ~DC_CTRL_RGN_OP_MSK;
+		if (op & OP_INV)
+			val |= DC_CTRL_RGN_OP_INV;
+	}
+	write_aux_reg(ctl, val);
+}
+
+#endif
+
+
+static inline void __after_dc_op(const int op)
+{
+	if (op & OP_FLUSH) {
+		const unsigned int ctl = ARC_REG_DC_CTRL;
+		unsigned int reg;
+
+		/* flush / flush-n-inv both wait */
+		while ((reg = read_aux_reg(ctl)) & DC_CTRL_FLUSH_STATUS)
+			;
+
+		/* Switch back to default Invalidate mode */
+		if (op == OP_FLUSH_N_INV)
+			write_aux_reg(ctl, reg & ~DC_CTRL_INV_MODE_FLUSH);
+	}
+}
+
+/*
+ * Operation on Entire D-Cache
+ * @op = {OP_INV, OP_FLUSH, OP_FLUSH_N_INV}
+ * Note that constant propagation ensures all the checks are gone
+ * in generated code
+ */
+static inline void __dc_entire_op(const int op)
+{
+	int aux;
+
+	__before_dc_op(op);
+
+	if (op & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
+		aux = ARC_REG_DC_IVDC;
+	else
+		aux = ARC_REG_DC_FLSH;
+
+	write_aux_reg(aux, 0x1);
+
+	__after_dc_op(op);
+}
+
+static inline void __dc_disable(void)
+{
+	const int r = ARC_REG_DC_CTRL;
+
+	__dc_entire_op(OP_FLUSH_N_INV);
+	write_aux_reg(r, read_aux_reg(r) | DC_CTRL_DIS);
+}
+
+static void __dc_enable(void)
+{
+	const int r = ARC_REG_DC_CTRL;
+
+	write_aux_reg(r, read_aux_reg(r) & ~DC_CTRL_DIS);
+}
+
+/* For kernel mappings cache operation: index is same as paddr */
+#define __dc_line_op_k(p, sz, op)	__dc_line_op(p, p, sz, op)
+
+/*
+ * D-Cache Line ops: Per Line INV (discard or wback+discard) or FLUSH (wback)
+ */
+static inline void __dc_line_op(phys_addr_t paddr, unsigned long vaddr,
+				unsigned long sz, const int op)
+{
+	const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	__before_dc_op(op);
+
+	__cache_line_loop(paddr, vaddr, sz, op, full_page);
+
+	__after_dc_op(op);
+
+	local_irq_restore(flags);
+}
+
+#else
+
+#define __dc_entire_op(op)
+#define __dc_disable()
+#define __dc_enable()
+#define __dc_line_op(paddr, vaddr, sz, op)
+#define __dc_line_op_k(paddr, sz, op)
+
+#endif /* CONFIG_ARC_HAS_DCACHE */
+
+#ifdef CONFIG_ARC_HAS_ICACHE
+
+static inline void __ic_entire_inv(void)
+{
+	write_aux_reg(ARC_REG_IC_IVIC, 1);
+	read_aux_reg(ARC_REG_IC_CTRL);	/* blocks */
+}
+
+static inline void
+__ic_line_inv_vaddr_local(phys_addr_t paddr, unsigned long vaddr,
+			  unsigned long sz)
+{
+	const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	(*_cache_line_loop_ic_fn)(paddr, vaddr, sz, OP_INV_IC, full_page);
+	local_irq_restore(flags);
+}
+
+#ifndef CONFIG_SMP
+
+#define __ic_line_inv_vaddr(p, v, s)	__ic_line_inv_vaddr_local(p, v, s)
+
+#else
+
+struct ic_inv_args {
+	phys_addr_t paddr, vaddr;
+	int sz;
+};
+
+static void __ic_line_inv_vaddr_helper(void *info)
+{
+        struct ic_inv_args *ic_inv = info;
+
+        __ic_line_inv_vaddr_local(ic_inv->paddr, ic_inv->vaddr, ic_inv->sz);
+}
+
+static void __ic_line_inv_vaddr(phys_addr_t paddr, unsigned long vaddr,
+				unsigned long sz)
+{
+	struct ic_inv_args ic_inv = {
+		.paddr = paddr,
+		.vaddr = vaddr,
+		.sz    = sz
+	};
+
+	on_each_cpu(__ic_line_inv_vaddr_helper, &ic_inv, 1);
+}
+
+#endif	/* CONFIG_SMP */
+
+#else	/* !CONFIG_ARC_HAS_ICACHE */
+
+#define __ic_entire_inv()
+#define __ic_line_inv_vaddr(pstart, vstart, sz)
+
+#endif /* CONFIG_ARC_HAS_ICACHE */
+
+noinline void slc_op_rgn(phys_addr_t paddr, unsigned long sz, const int op)
+{
+#ifdef CONFIG_ISA_ARCV2
+	/*
+	 * SLC is shared between all cores and concurrent aux operations from
+	 * multiple cores need to be serialized using a spinlock
+	 * A concurrent operation can be silently ignored and/or the old/new
+	 * operation can remain incomplete forever (lockup in SLC_CTRL_BUSY loop
+	 * below)
+	 */
+	static DEFINE_SPINLOCK(lock);
+	unsigned long flags;
+	unsigned int ctrl;
+	phys_addr_t end;
+
+	spin_lock_irqsave(&lock, flags);
+
+	/*
+	 * The Region Flush operation is specified by CTRL.RGN_OP[11..9]
+	 *  - b'000 (default) is Flush,
+	 *  - b'001 is Invalidate if CTRL.IM == 0
+	 *  - b'001 is Flush-n-Invalidate if CTRL.IM == 1
+	 */
+	ctrl = read_aux_reg(ARC_REG_SLC_CTRL);
+
+	/* Don't rely on default value of IM bit */
+	if (!(op & OP_FLUSH))		/* i.e. OP_INV */
+		ctrl &= ~SLC_CTRL_IM;	/* clear IM: Disable flush before Inv */
+	else
+		ctrl |= SLC_CTRL_IM;
+
+	if (op & OP_INV)
+		ctrl |= SLC_CTRL_RGN_OP_INV;	/* Inv or flush-n-inv */
+	else
+		ctrl &= ~SLC_CTRL_RGN_OP_INV;
+
+	write_aux_reg(ARC_REG_SLC_CTRL, ctrl);
+
+	/*
+	 * Lower bits are ignored, no need to clip
+	 * END needs to be setup before START (latter triggers the operation)
+	 * END can't be same as START, so add (l2_line_sz - 1) to sz
+	 */
+	end = paddr + sz + l2_line_sz - 1;
+	if (is_pae40_enabled())
+		write_aux_reg(ARC_REG_SLC_RGN_END1, upper_32_bits(end));
+
+	write_aux_reg(ARC_REG_SLC_RGN_END, lower_32_bits(end));
+
+	if (is_pae40_enabled())
+		write_aux_reg(ARC_REG_SLC_RGN_START1, upper_32_bits(paddr));
+
+	write_aux_reg(ARC_REG_SLC_RGN_START, lower_32_bits(paddr));
+
+	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
+	read_aux_reg(ARC_REG_SLC_CTRL);
+
+	while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
+
+	spin_unlock_irqrestore(&lock, flags);
+#endif
+}
+
+noinline void slc_op_line(phys_addr_t paddr, unsigned long sz, const int op)
+{
+#ifdef CONFIG_ISA_ARCV2
+	/*
+	 * SLC is shared between all cores and concurrent aux operations from
+	 * multiple cores need to be serialized using a spinlock
+	 * A concurrent operation can be silently ignored and/or the old/new
+	 * operation can remain incomplete forever (lockup in SLC_CTRL_BUSY loop
+	 * below)
+	 */
+	static DEFINE_SPINLOCK(lock);
+
+	const unsigned long SLC_LINE_MASK = ~(l2_line_sz - 1);
+	unsigned int ctrl, cmd;
+	unsigned long flags;
+	int num_lines;
+
+	spin_lock_irqsave(&lock, flags);
+
+	ctrl = read_aux_reg(ARC_REG_SLC_CTRL);
+
+	/* Don't rely on default value of IM bit */
+	if (!(op & OP_FLUSH))		/* i.e. OP_INV */
+		ctrl &= ~SLC_CTRL_IM;	/* clear IM: Disable flush before Inv */
+	else
+		ctrl |= SLC_CTRL_IM;
+
+	write_aux_reg(ARC_REG_SLC_CTRL, ctrl);
+
+	cmd = op & OP_INV ? ARC_AUX_SLC_IVDL : ARC_AUX_SLC_FLDL;
+
+	sz += paddr & ~SLC_LINE_MASK;
+	paddr &= SLC_LINE_MASK;
+
+	num_lines = DIV_ROUND_UP(sz, l2_line_sz);
+
+	while (num_lines-- > 0) {
+		write_aux_reg(cmd, paddr);
+		paddr += l2_line_sz;
+	}
+
+	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
+	read_aux_reg(ARC_REG_SLC_CTRL);
+
+	while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
+
+	spin_unlock_irqrestore(&lock, flags);
+#endif
+}
+
+#define slc_op(paddr, sz, op)	slc_op_rgn(paddr, sz, op)
+
+noinline static void slc_entire_op(const int op)
+{
+	unsigned int ctrl, r = ARC_REG_SLC_CTRL;
+
+	ctrl = read_aux_reg(r);
+
+	if (!(op & OP_FLUSH))		/* i.e. OP_INV */
+		ctrl &= ~SLC_CTRL_IM;	/* clear IM: Disable flush before Inv */
+	else
+		ctrl |= SLC_CTRL_IM;
+
+	write_aux_reg(r, ctrl);
+
+	if (op & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
+		write_aux_reg(ARC_REG_SLC_INVALIDATE, 0x1);
+	else
+		write_aux_reg(ARC_REG_SLC_FLUSH, 0x1);
+
+	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
+	read_aux_reg(r);
+
+	/* Important to wait for flush to complete */
+	while (read_aux_reg(r) & SLC_CTRL_BUSY);
+}
+
+static inline void arc_slc_disable(void)
+{
+	const int r = ARC_REG_SLC_CTRL;
+
+	slc_entire_op(OP_FLUSH_N_INV);
+	write_aux_reg(r, read_aux_reg(r) | SLC_CTRL_DIS);
+}
+
+static inline void arc_slc_enable(void)
+{
+	const int r = ARC_REG_SLC_CTRL;
+
+	write_aux_reg(r, read_aux_reg(r) & ~SLC_CTRL_DIS);
+}
+
+/***********************************************************
+ * Exported APIs
+ */
+
+/*
+ * Handle cache congruency of kernel and userspace mappings of page when kernel
+ * writes-to/reads-from
+ *
+ * The idea is to defer flushing of kernel mapping after a WRITE, possible if:
+ *  -dcache is NOT aliasing, hence any U/K-mappings of page are congruent
+ *  -U-mapping doesn't exist yet for page (finalised in update_mmu_cache)
+ *  -In SMP, if hardware caches are coherent
+ *
+ * There's a corollary case, where kernel READs from a userspace mapped page.
+ * If the U-mapping is not congruent to to K-mapping, former needs flushing.
+ */
+void flush_dcache_page(struct page *page)
+{
+	struct address_space *mapping;
+
+	if (!cache_is_vipt_aliasing()) {
+		clear_bit(PG_dc_clean, &page->flags);
+		return;
+	}
+
+	/* don't handle anon pages here */
+	mapping = page_mapping_file(page);
+	if (!mapping)
+		return;
+
+	/*
+	 * pagecache page, file not yet mapped to userspace
+	 * Make a note that K-mapping is dirty
+	 */
+	if (!mapping_mapped(mapping)) {
+		clear_bit(PG_dc_clean, &page->flags);
+	} else if (page_mapcount(page)) {
+
+		/* kernel reading from page with U-mapping */
+		phys_addr_t paddr = (unsigned long)page_address(page);
+		unsigned long vaddr = page->index << PAGE_SHIFT;
+
+		if (addr_not_cache_congruent(paddr, vaddr))
+			__flush_dcache_page(paddr, vaddr);
+	}
+}
+EXPORT_SYMBOL(flush_dcache_page);
+
+/*
+ * DMA ops for systems with L1 cache only
+ * Make memory coherent with L1 cache by flushing/invalidating L1 lines
+ */
+static void __dma_cache_wback_inv_l1(phys_addr_t start, unsigned long sz)
+{
+	__dc_line_op_k(start, sz, OP_FLUSH_N_INV);
+}
+
+static void __dma_cache_inv_l1(phys_addr_t start, unsigned long sz)
+{
+	__dc_line_op_k(start, sz, OP_INV);
+}
+
+static void __dma_cache_wback_l1(phys_addr_t start, unsigned long sz)
+{
+	__dc_line_op_k(start, sz, OP_FLUSH);
+}
+
+/*
+ * DMA ops for systems with both L1 and L2 caches, but without IOC
+ * Both L1 and L2 lines need to be explicitly flushed/invalidated
+ */
+static void __dma_cache_wback_inv_slc(phys_addr_t start, unsigned long sz)
+{
+	__dc_line_op_k(start, sz, OP_FLUSH_N_INV);
+	slc_op(start, sz, OP_FLUSH_N_INV);
+}
+
+static void __dma_cache_inv_slc(phys_addr_t start, unsigned long sz)
+{
+	__dc_line_op_k(start, sz, OP_INV);
+	slc_op(start, sz, OP_INV);
+}
+
+static void __dma_cache_wback_slc(phys_addr_t start, unsigned long sz)
+{
+	__dc_line_op_k(start, sz, OP_FLUSH);
+	slc_op(start, sz, OP_FLUSH);
+}
+
+/*
+ * Exported DMA API
+ */
+void dma_cache_wback_inv(phys_addr_t start, unsigned long sz)
+{
+	__dma_cache_wback_inv(start, sz);
+}
+EXPORT_SYMBOL(dma_cache_wback_inv);
+
+void dma_cache_inv(phys_addr_t start, unsigned long sz)
+{
+	__dma_cache_inv(start, sz);
+}
+EXPORT_SYMBOL(dma_cache_inv);
+
+void dma_cache_wback(phys_addr_t start, unsigned long sz)
+{
+	__dma_cache_wback(start, sz);
+}
+EXPORT_SYMBOL(dma_cache_wback);
+
+/*
+ * This is API for making I/D Caches consistent when modifying
+ * kernel code (loadable modules, kprobes, kgdb...)
+ * This is called on insmod, with kernel virtual address for CODE of
+ * the module. ARC cache maintenance ops require PHY address thus we
+ * need to convert vmalloc addr to PHY addr
+ */
+void flush_icache_range(unsigned long kstart, unsigned long kend)
+{
+	unsigned int tot_sz;
+
+	WARN(kstart < TASK_SIZE, "%s() can't handle user vaddr", __func__);
+
+	/* Shortcut for bigger flush ranges.
+	 * Here we don't care if this was kernel virtual or phy addr
+	 */
+	tot_sz = kend - kstart;
+	if (tot_sz > PAGE_SIZE) {
+		flush_cache_all();
+		return;
+	}
+
+	/* Case: Kernel Phy addr (0x8000_0000 onwards) */
+	if (likely(kstart > PAGE_OFFSET)) {
+		/*
+		 * The 2nd arg despite being paddr will be used to index icache
+		 * This is OK since no alternate virtual mappings will exist
+		 * given the callers for this case: kprobe/kgdb in built-in
+		 * kernel code only.
+		 */
+		__sync_icache_dcache(kstart, kstart, kend - kstart);
+		return;
+	}
+
+	/*
+	 * Case: Kernel Vaddr (0x7000_0000 to 0x7fff_ffff)
+	 * (1) ARC Cache Maintenance ops only take Phy addr, hence special
+	 *     handling of kernel vaddr.
+	 *
+	 * (2) Despite @tot_sz being < PAGE_SIZE (bigger cases handled already),
+	 *     it still needs to handle  a 2 page scenario, where the range
+	 *     straddles across 2 virtual pages and hence need for loop
+	 */
+	while (tot_sz > 0) {
+		unsigned int off, sz;
+		unsigned long phy, pfn;
+
+		off = kstart % PAGE_SIZE;
+		pfn = vmalloc_to_pfn((void *)kstart);
+		phy = (pfn << PAGE_SHIFT) + off;
+		sz = min_t(unsigned int, tot_sz, PAGE_SIZE - off);
+		__sync_icache_dcache(phy, kstart, sz);
+		kstart += sz;
+		tot_sz -= sz;
+	}
+}
+EXPORT_SYMBOL(flush_icache_range);
+
+/*
+ * General purpose helper to make I and D cache lines consistent.
+ * @paddr is phy addr of region
+ * @vaddr is typically user vaddr (breakpoint) or kernel vaddr (vmalloc)
+ *    However in one instance, when called by kprobe (for a breakpt in
+ *    builtin kernel code) @vaddr will be paddr only, meaning CDU operation will
+ *    use a paddr to index the cache (despite VIPT). This is fine since since a
+ *    builtin kernel page will not have any virtual mappings.
+ *    kprobe on loadable module will be kernel vaddr.
+ */
+void __sync_icache_dcache(phys_addr_t paddr, unsigned long vaddr, int len)
+{
+	__dc_line_op(paddr, vaddr, len, OP_FLUSH_N_INV);
+	__ic_line_inv_vaddr(paddr, vaddr, len);
+}
+
+/* wrapper to compile time eliminate alignment checks in flush loop */
+void __inv_icache_page(phys_addr_t paddr, unsigned long vaddr)
+{
+	__ic_line_inv_vaddr(paddr, vaddr, PAGE_SIZE);
+}
+
+/*
+ * wrapper to clearout kernel or userspace mappings of a page
+ * For kernel mappings @vaddr == @paddr
+ */
+void __flush_dcache_page(phys_addr_t paddr, unsigned long vaddr)
+{
+	__dc_line_op(paddr, vaddr & PAGE_MASK, PAGE_SIZE, OP_FLUSH_N_INV);
+}
+
+noinline void flush_cache_all(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	__ic_entire_inv();
+	__dc_entire_op(OP_FLUSH_N_INV);
+
+	local_irq_restore(flags);
+
+}
+
+#ifdef CONFIG_ARC_CACHE_VIPT_ALIASING
+
+void flush_cache_mm(struct mm_struct *mm)
+{
+	flush_cache_all();
+}
+
+void flush_cache_page(struct vm_area_struct *vma, unsigned long u_vaddr,
+		      unsigned long pfn)
+{
+	phys_addr_t paddr = pfn << PAGE_SHIFT;
+
+	u_vaddr &= PAGE_MASK;
+
+	__flush_dcache_page(paddr, u_vaddr);
+
+	if (vma->vm_flags & VM_EXEC)
+		__inv_icache_page(paddr, u_vaddr);
+}
+
+void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
+		       unsigned long end)
+{
+	flush_cache_all();
+}
+
+void flush_anon_page(struct vm_area_struct *vma, struct page *page,
+		     unsigned long u_vaddr)
+{
+	/* TBD: do we really need to clear the kernel mapping */
+	__flush_dcache_page((phys_addr_t)page_address(page), u_vaddr);
+	__flush_dcache_page((phys_addr_t)page_address(page),
+			    (phys_addr_t)page_address(page));
+
+}
+
+#endif
+
+void copy_user_highpage(struct page *to, struct page *from,
+	unsigned long u_vaddr, struct vm_area_struct *vma)
+{
+	void *kfrom = kmap_atomic(from);
+	void *kto = kmap_atomic(to);
+	int clean_src_k_mappings = 0;
+
+	/*
+	 * If SRC page was already mapped in userspace AND it's U-mapping is
+	 * not congruent with K-mapping, sync former to physical page so that
+	 * K-mapping in memcpy below, sees the right data
+	 *
+	 * Note that while @u_vaddr refers to DST page's userspace vaddr, it is
+	 * equally valid for SRC page as well
+	 *
+	 * For !VIPT cache, all of this gets compiled out as
+	 * addr_not_cache_congruent() is 0
+	 */
+	if (page_mapcount(from) && addr_not_cache_congruent(kfrom, u_vaddr)) {
+		__flush_dcache_page((unsigned long)kfrom, u_vaddr);
+		clean_src_k_mappings = 1;
+	}
+
+	copy_page(kto, kfrom);
+
+	/*
+	 * Mark DST page K-mapping as dirty for a later finalization by
+	 * update_mmu_cache(). Although the finalization could have been done
+	 * here as well (given that both vaddr/paddr are available).
+	 * But update_mmu_cache() already has code to do that for other
+	 * non copied user pages (e.g. read faults which wire in pagecache page
+	 * directly).
+	 */
+	clear_bit(PG_dc_clean, &to->flags);
+
+	/*
+	 * if SRC was already usermapped and non-congruent to kernel mapping
+	 * sync the kernel mapping back to physical page
+	 */
+	if (clean_src_k_mappings) {
+		__flush_dcache_page((unsigned long)kfrom, (unsigned long)kfrom);
+		set_bit(PG_dc_clean, &from->flags);
+	} else {
+		clear_bit(PG_dc_clean, &from->flags);
+	}
+
+	kunmap_atomic(kto);
+	kunmap_atomic(kfrom);
+}
+
+void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
+{
+	clear_page(to);
+	clear_bit(PG_dc_clean, &page->flags);
+}
+EXPORT_SYMBOL(clear_user_page);
+
+/**********************************************************************
+ * Explicit Cache flush request from user space via syscall
+ * Needed for JITs which generate code on the fly
+ */
+SYSCALL_DEFINE3(cacheflush, uint32_t, start, uint32_t, sz, uint32_t, flags)
+{
+	/* TBD: optimize this */
+	flush_cache_all();
+	return 0;
+}
+
+/*
+ * IO-Coherency (IOC) setup rules:
+ *
+ * 1. Needs to be at system level, so only once by Master core
+ *    Non-Masters need not be accessing caches at that time
+ *    - They are either HALT_ON_RESET and kick started much later or
+ *    - if run on reset, need to ensure that arc_platform_smp_wait_to_boot()
+ *      doesn't perturb caches or coherency unit
+ *
+ * 2. caches (L1 and SLC) need to be purged (flush+inv) before setting up IOC,
+ *    otherwise any straggler data might behave strangely post IOC enabling
+ *
+ * 3. All Caches need to be disabled when setting up IOC to elide any in-flight
+ *    Coherency transactions
+ */
+noinline void __init arc_ioc_setup(void)
+{
+	unsigned int ioc_base, mem_sz;
+
+	/*
+	 * If IOC was already enabled (due to bootloader) it technically needs to
+	 * be reconfigured with aperture base,size corresponding to Linux memory map
+	 * which will certainly be different than uboot's. But disabling and
+	 * reenabling IOC when DMA might be potentially active is tricky business.
+	 * To avoid random memory issues later, just panic here and ask user to
+	 * upgrade bootloader to one which doesn't enable IOC
+	 */
+	if (read_aux_reg(ARC_REG_IO_COH_ENABLE) & ARC_IO_COH_ENABLE_BIT)
+		panic("IOC already enabled, please upgrade bootloader!\n");
+
+	if (!ioc_enable)
+		return;
+
+	/*
+	 * As for today we don't support both IOC and ZONE_HIGHMEM enabled
+	 * simultaneously. This happens because as of today IOC aperture covers
+	 * only ZONE_NORMAL (low mem) and any dma transactions outside this
+	 * region won't be HW coherent.
+	 * If we want to use both IOC and ZONE_HIGHMEM we can use
+	 * bounce_buffer to handle dma transactions to HIGHMEM.
+	 * Also it is possible to modify dma_direct cache ops or increase IOC
+	 * aperture size if we are planning to use HIGHMEM without PAE.
+	 */
+	if (IS_ENABLED(CONFIG_HIGHMEM))
+		panic("IOC and HIGHMEM can't be used simultaneously");
+
+	/* Flush + invalidate + disable L1 dcache */
+	__dc_disable();
+
+	/* Flush + invalidate SLC */
+	if (read_aux_reg(ARC_REG_SLC_BCR))
+		slc_entire_op(OP_FLUSH_N_INV);
+
+	/*
+	 * currently IOC Aperture covers entire DDR
+	 * TBD: fix for PGU + 1GB of low mem
+	 * TBD: fix for PAE
+	 */
+	mem_sz = arc_get_mem_sz();
+
+	if (!is_power_of_2(mem_sz) || mem_sz < 4096)
+		panic("IOC Aperture size must be power of 2 larger than 4KB");
+
+	/*
+	 * IOC Aperture size decoded as 2 ^ (SIZE + 2) KB,
+	 * so setting 0x11 implies 512MB, 0x12 implies 1GB...
+	 */
+	write_aux_reg(ARC_REG_IO_COH_AP0_SIZE, order_base_2(mem_sz >> 10) - 2);
+
+	/* for now assume kernel base is start of IOC aperture */
+	ioc_base = CONFIG_LINUX_RAM_BASE;
+
+	if (ioc_base % mem_sz != 0)
+		panic("IOC Aperture start must be aligned to the size of the aperture");
+
+	write_aux_reg(ARC_REG_IO_COH_AP0_BASE, ioc_base >> 12);
+	write_aux_reg(ARC_REG_IO_COH_PARTIAL, ARC_IO_COH_PARTIAL_BIT);
+	write_aux_reg(ARC_REG_IO_COH_ENABLE, ARC_IO_COH_ENABLE_BIT);
+
+	/* Re-enable L1 dcache */
+	__dc_enable();
+}
+
+/*
+ * Cache related boot time checks/setups only needed on master CPU:
+ *  - Geometry checks (kernel build and hardware agree: e.g. L1_CACHE_BYTES)
+ *    Assume SMP only, so all cores will have same cache config. A check on
+ *    one core suffices for all
+ *  - IOC setup / dma callbacks only need to be done once
+ */
+void __init arc_cache_init_master(void)
+{
+	unsigned int __maybe_unused cpu = smp_processor_id();
+
+	if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) {
+		struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
+
+		if (!ic->line_len)
+			panic("cache support enabled but non-existent cache\n");
+
+		if (ic->line_len != L1_CACHE_BYTES)
+			panic("ICache line [%d] != kernel Config [%d]",
+			      ic->line_len, L1_CACHE_BYTES);
+
+		/*
+		 * In MMU v4 (HS38x) the aliasing icache config uses IVIL/PTAG
+		 * pair to provide vaddr/paddr respectively, just as in MMU v3
+		 */
+		if (is_isa_arcv2() && ic->alias)
+			_cache_line_loop_ic_fn = __cache_line_loop_v3;
+		else
+			_cache_line_loop_ic_fn = __cache_line_loop;
+	}
+
+	if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) {
+		struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
+
+		if (!dc->line_len)
+			panic("cache support enabled but non-existent cache\n");
+
+		if (dc->line_len != L1_CACHE_BYTES)
+			panic("DCache line [%d] != kernel Config [%d]",
+			      dc->line_len, L1_CACHE_BYTES);
+
+		/* check for D-Cache aliasing on ARCompact: ARCv2 has PIPT */
+		if (is_isa_arcompact()) {
+			int handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
+			int num_colors = dc->sz_k/dc->assoc/TO_KB(PAGE_SIZE);
+
+			if (dc->alias) {
+				if (!handled)
+					panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
+				if (CACHE_COLORS_NUM != num_colors)
+					panic("CACHE_COLORS_NUM not optimized for config\n");
+			} else if (!dc->alias && handled) {
+				panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
+			}
+		}
+	}
+
+	/*
+	 * Check that SMP_CACHE_BYTES (and hence ARCH_DMA_MINALIGN) is larger
+	 * or equal to any cache line length.
+	 */
+	BUILD_BUG_ON_MSG(L1_CACHE_BYTES > SMP_CACHE_BYTES,
+			 "SMP_CACHE_BYTES must be >= any cache line length");
+	if (is_isa_arcv2() && (l2_line_sz > SMP_CACHE_BYTES))
+		panic("L2 Cache line [%d] > kernel Config [%d]\n",
+		      l2_line_sz, SMP_CACHE_BYTES);
+
+	/* Note that SLC disable not formally supported till HS 3.0 */
+	if (is_isa_arcv2() && l2_line_sz && !slc_enable)
+		arc_slc_disable();
+
+	if (is_isa_arcv2() && ioc_exists)
+		arc_ioc_setup();
+
+	if (is_isa_arcv2() && l2_line_sz && slc_enable) {
+		__dma_cache_wback_inv = __dma_cache_wback_inv_slc;
+		__dma_cache_inv = __dma_cache_inv_slc;
+		__dma_cache_wback = __dma_cache_wback_slc;
+	} else {
+		__dma_cache_wback_inv = __dma_cache_wback_inv_l1;
+		__dma_cache_inv = __dma_cache_inv_l1;
+		__dma_cache_wback = __dma_cache_wback_l1;
+	}
+	/*
+	 * In case of IOC (say IOC+SLC case), pointers above could still be set
+	 * but end up not being relevant as the first function in chain is not
+	 * called at all for @dma_direct_ops
+	 *     arch_sync_dma_for_cpu() -> dma_cache_*() -> __dma_cache_*()
+	 */
+}
+
+void __ref arc_cache_init(void)
+{
+	unsigned int __maybe_unused cpu = smp_processor_id();
+	char str[256];
+
+	pr_info("%s", arc_cache_mumbojumbo(0, str, sizeof(str)));
+
+	if (!cpu)
+		arc_cache_init_master();
+
+	/*
+	 * In PAE regime, TLB and cache maintenance ops take wider addresses
+	 * And even if PAE is not enabled in kernel, the upper 32-bits still need
+	 * to be zeroed to keep the ops sane.
+	 * As an optimization for more common !PAE enabled case, zero them out
+	 * once at init, rather than checking/setting to 0 for every runtime op
+	 */
+	if (is_isa_arcv2() && pae40_exist_but_not_enab()) {
+
+		if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE))
+			write_aux_reg(ARC_REG_IC_PTAG_HI, 0);
+
+		if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE))
+			write_aux_reg(ARC_REG_DC_PTAG_HI, 0);
+
+		if (l2_line_sz) {
+			write_aux_reg(ARC_REG_SLC_RGN_END1, 0);
+			write_aux_reg(ARC_REG_SLC_RGN_START1, 0);
+		}
+	}
+}
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
new file mode 100644
index 000000000..c75d5c347
--- /dev/null
+++ b/arch/arc/mm/dma.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/dma-noncoherent.h>
+#include <asm/cache.h>
+#include <asm/cacheflush.h>
+
+/*
+ * ARCH specific callbacks for generic noncoherent DMA ops (dma/noncoherent.c)
+ *  - hardware IOC not available (or "dma-coherent" not set for device in DT)
+ *  - But still handle both coherent and non-coherent requests from caller
+ *
+ * For DMA coherent hardware (IOC) generic code suffices
+ */
+void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		gfp_t gfp, unsigned long attrs)
+{
+	unsigned long order = get_order(size);
+	struct page *page;
+	phys_addr_t paddr;
+	void *kvaddr;
+	bool need_coh = !(attrs & DMA_ATTR_NON_CONSISTENT);
+
+	/*
+	 * __GFP_HIGHMEM flag is cleared by upper layer functions
+	 * (in include/linux/dma-mapping.h) so we should never get a
+	 * __GFP_HIGHMEM here.
+	 */
+	BUG_ON(gfp & __GFP_HIGHMEM);
+
+	page = alloc_pages(gfp, order);
+	if (!page)
+		return NULL;
+
+	/* This is linear addr (0x8000_0000 based) */
+	paddr = page_to_phys(page);
+
+	*dma_handle = paddr;
+
+	/*
+	 * A coherent buffer needs MMU mapping to enforce non-cachability.
+	 * kvaddr is kernel Virtual address (0x7000_0000 based).
+	 */
+	if (need_coh) {
+		kvaddr = ioremap_nocache(paddr, size);
+		if (kvaddr == NULL) {
+			__free_pages(page, order);
+			return NULL;
+		}
+	} else {
+		kvaddr = (void *)(u32)paddr;
+	}
+
+	/*
+	 * Evict any existing L1 and/or L2 lines for the backing page
+	 * in case it was used earlier as a normal "cached" page.
+	 * Yeah this bit us - STAR 9000898266
+	 *
+	 * Although core does call flush_cache_vmap(), it gets kvaddr hence
+	 * can't be used to efficiently flush L1 and/or L2 which need paddr
+	 * Currently flush_cache_vmap nukes the L1 cache completely which
+	 * will be optimized as a separate commit
+	 */
+	if (need_coh)
+		dma_cache_wback_inv(paddr, size);
+
+	return kvaddr;
+}
+
+void arch_dma_free(struct device *dev, size_t size, void *vaddr,
+		dma_addr_t dma_handle, unsigned long attrs)
+{
+	phys_addr_t paddr = dma_handle;
+	struct page *page = virt_to_page(paddr);
+
+	if (!(attrs & DMA_ATTR_NON_CONSISTENT))
+		iounmap((void __force __iomem *)vaddr);
+
+	__free_pages(page, get_order(size));
+}
+
+int arch_dma_mmap(struct device *dev, struct vm_area_struct *vma,
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs)
+{
+	unsigned long user_count = vma_pages(vma);
+	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	unsigned long pfn = __phys_to_pfn(dma_addr);
+	unsigned long off = vma->vm_pgoff;
+	int ret = -ENXIO;
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
+		return ret;
+
+	if (off < count && user_count <= (count - off)) {
+		ret = remap_pfn_range(vma, vma->vm_start,
+				      pfn + off,
+				      user_count << PAGE_SHIFT,
+				      vma->vm_page_prot);
+	}
+
+	return ret;
+}
+
+/*
+ * Cache operations depending on function and direction argument, inspired by
+ * https://lkml.org/lkml/2018/5/18/979
+ * "dma_sync_*_for_cpu and direction=TO_DEVICE (was Re: [PATCH 02/20]
+ * dma-mapping: provide a generic dma-noncoherent implementation)"
+ *
+ *          |   map          ==  for_device     |   unmap     ==  for_cpu
+ *          |----------------------------------------------------------------
+ * TO_DEV   |   writeback        writeback      |   none          none
+ * FROM_DEV |   invalidate       invalidate     |   invalidate*   invalidate*
+ * BIDIR    |   writeback+inv    writeback+inv  |   invalidate    invalidate
+ *
+ *     [*] needed for CPU speculative prefetches
+ *
+ * NOTE: we don't check the validity of direction argument as it is done in
+ * upper layer functions (in include/linux/dma-mapping.h)
+ */
+
+void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
+		size_t size, enum dma_data_direction dir)
+{
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		dma_cache_wback(paddr, size);
+		break;
+
+	case DMA_FROM_DEVICE:
+		dma_cache_inv(paddr, size);
+		break;
+
+	case DMA_BIDIRECTIONAL:
+		dma_cache_wback_inv(paddr, size);
+		break;
+
+	default:
+		break;
+	}
+}
+
+void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
+		size_t size, enum dma_data_direction dir)
+{
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		break;
+
+	/* FROM_DEVICE invalidate needed if speculative CPU prefetch only */
+	case DMA_FROM_DEVICE:
+	case DMA_BIDIRECTIONAL:
+		dma_cache_inv(paddr, size);
+		break;
+
+	default:
+		break;
+	}
+}
+
+/*
+ * Plug in coherent or noncoherent dma ops
+ */
+void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+			const struct iommu_ops *iommu, bool coherent)
+{
+	/*
+	 * IOC hardware snoops all DMA traffic keeping the caches consistent
+	 * with memory - eliding need for any explicit cache maintenance of
+	 * DMA buffers - so we can use dma_direct cache ops.
+	 */
+	if (is_isa_arcv2() && ioc_enable && coherent) {
+		set_dma_ops(dev, &dma_direct_ops);
+		dev_info(dev, "use dma_direct_ops cache ops\n");
+	} else {
+		set_dma_ops(dev, &dma_noncoherent_ops);
+		dev_info(dev, "use dma_noncoherent_ops cache ops\n");
+	}
+}
diff --git a/arch/arc/mm/extable.c b/arch/arc/mm/extable.c
new file mode 100644
index 000000000..72125a34e
--- /dev/null
+++ b/arch/arc/mm/extable.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Borrowed heavily from MIPS
+ */
+
+#include <linux/export.h>
+#include <linux/extable.h>
+#include <linux/uaccess.h>
+
+int fixup_exception(struct pt_regs *regs)
+{
+	const struct exception_table_entry *fixup;
+
+	fixup = search_exception_tables(instruction_pointer(regs));
+	if (fixup) {
+		regs->ret = fixup->fixup;
+
+		return 1;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
+
+unsigned long arc_clear_user_noinline(void __user *to,
+		unsigned long n)
+{
+	return __arc_clear_user(to, n);
+}
+EXPORT_SYMBOL(arc_clear_user_noinline);
+
+long arc_strncpy_from_user_noinline(char *dst, const char __user *src,
+		long count)
+{
+	return __arc_strncpy_from_user(dst, src, count);
+}
+EXPORT_SYMBOL(arc_strncpy_from_user_noinline);
+
+long arc_strnlen_user_noinline(const char __user *src, long n)
+{
+	return __arc_strnlen_user(src, n);
+}
+EXPORT_SYMBOL(arc_strnlen_user_noinline);
+#endif
diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
new file mode 100644
index 000000000..4e8143de3
--- /dev/null
+++ b/arch/arc/mm/fault.c
@@ -0,0 +1,238 @@
+/* Page Fault Handling for ARC (TLB Miss / ProtV)
+ *
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/signal.h>
+#include <linux/interrupt.h>
+#include <linux/sched/signal.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/uaccess.h>
+#include <linux/kdebug.h>
+#include <linux/perf_event.h>
+#include <linux/mm_types.h>
+#include <asm/pgalloc.h>
+#include <asm/mmu.h>
+
+/*
+ * kernel virtual address is required to implement vmalloc/pkmap/fixmap
+ * Refer to asm/processor.h for System Memory Map
+ *
+ * It simply copies the PMD entry (pointer to 2nd level page table or hugepage)
+ * from swapper pgdir to task pgdir. The 2nd level table/page is thus shared
+ */
+noinline static int handle_kernel_vaddr_fault(unsigned long address)
+{
+	/*
+	 * Synchronize this task's top level page-table
+	 * with the 'reference' page table.
+	 */
+	pgd_t *pgd, *pgd_k;
+	pud_t *pud, *pud_k;
+	pmd_t *pmd, *pmd_k;
+
+	pgd = pgd_offset_fast(current->active_mm, address);
+	pgd_k = pgd_offset_k(address);
+
+	if (!pgd_present(*pgd_k))
+		goto bad_area;
+
+	pud = pud_offset(pgd, address);
+	pud_k = pud_offset(pgd_k, address);
+	if (!pud_present(*pud_k))
+		goto bad_area;
+
+	pmd = pmd_offset(pud, address);
+	pmd_k = pmd_offset(pud_k, address);
+	if (!pmd_present(*pmd_k))
+		goto bad_area;
+
+	set_pmd(pmd, *pmd_k);
+
+	/* XXX: create the TLB entry here */
+	return 0;
+
+bad_area:
+	return 1;
+}
+
+void do_page_fault(unsigned long address, struct pt_regs *regs)
+{
+	struct vm_area_struct *vma = NULL;
+	struct task_struct *tsk = current;
+	struct mm_struct *mm = tsk->mm;
+	int si_code = SEGV_MAPERR;
+	int ret;
+	vm_fault_t fault;
+	int write = regs->ecr_cause & ECR_C_PROTV_STORE;  /* ST/EX */
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+
+	/*
+	 * 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 (address >= VMALLOC_START && !user_mode(regs)) {
+		ret = handle_kernel_vaddr_fault(address);
+		if (unlikely(ret))
+			goto no_context;
+		else
+			return;
+	}
+
+	/*
+	 * If we're in an interrupt or have no user
+	 * context, we must not take the fault..
+	 */
+	if (faulthandler_disabled() || !mm)
+		goto no_context;
+
+	if (user_mode(regs))
+		flags |= FAULT_FLAG_USER;
+retry:
+	down_read(&mm->mmap_sem);
+	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;
+
+	/* Handle protection violation, execute on heap or stack */
+
+	if ((regs->ecr_vec == ECR_V_PROTV) &&
+	    (regs->ecr_cause == ECR_C_PROTV_INST_FETCH))
+		goto bad_area;
+
+	if (write) {
+		if (!(vma->vm_flags & VM_WRITE))
+			goto bad_area;
+		flags |= FAULT_FLAG_WRITE;
+	} else {
+		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+			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, flags);
+
+	if (unlikely(fatal_signal_pending(current))) {
+
+		/*
+		 * if fault retry, mmap_sem already relinquished by core mm
+		 * so OK to return to user mode (with signal handled first)
+		 */
+		if (fault & VM_FAULT_RETRY) {
+			if (!user_mode(regs))
+				goto no_context;
+			return;
+		}
+	}
+
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+
+	if (likely(!(fault & VM_FAULT_ERROR))) {
+		if (flags & FAULT_FLAG_ALLOW_RETRY) {
+			/* To avoid updating stats twice for retry case */
+			if (fault & VM_FAULT_MAJOR) {
+				tsk->maj_flt++;
+				perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
+					      regs, address);
+			} else {
+				tsk->min_flt++;
+				perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
+					      regs, address);
+			}
+
+			if (fault & VM_FAULT_RETRY) {
+				flags &= ~FAULT_FLAG_ALLOW_RETRY;
+				flags |= FAULT_FLAG_TRIED;
+				goto retry;
+			}
+		}
+
+		/* Fault Handled Gracefully */
+		up_read(&mm->mmap_sem);
+		return;
+	}
+
+	if (fault & VM_FAULT_OOM)
+		goto out_of_memory;
+	else if (fault & VM_FAULT_SIGSEGV)
+		goto bad_area;
+	else if (fault & VM_FAULT_SIGBUS)
+		goto do_sigbus;
+
+	/* no man's land */
+	BUG();
+
+	/*
+	 * 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:
+	up_read(&mm->mmap_sem);
+
+	/* User mode accesses just cause a SIGSEGV */
+	if (user_mode(regs)) {
+		tsk->thread.fault_address = address;
+		force_sig_fault(SIGSEGV, si_code, (void __user *)address, tsk);
+		return;
+	}
+
+no_context:
+	/* Are we prepared to handle this kernel fault?
+	 *
+	 * (The kernel has valid exception-points in the source
+	 *  when it accesses user-memory. When it fails in one
+	 *  of those points, we find it in a table and do a jump
+	 *  to some fixup code that loads an appropriate error
+	 *  code)
+	 */
+	if (fixup_exception(regs))
+		return;
+
+	die("Oops", regs, address);
+
+out_of_memory:
+	up_read(&mm->mmap_sem);
+
+	if (user_mode(regs)) {
+		pagefault_out_of_memory();
+		return;
+	}
+
+	goto no_context;
+
+do_sigbus:
+	up_read(&mm->mmap_sem);
+
+	if (!user_mode(regs))
+		goto no_context;
+
+	tsk->thread.fault_address = address;
+	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, tsk);
+}
diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
new file mode 100644
index 000000000..77ff64a87
--- /dev/null
+++ b/arch/arc/mm/highmem.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2015 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/bootmem.h>
+#include <linux/export.h>
+#include <linux/highmem.h>
+#include <asm/processor.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+
+/*
+ * HIGHMEM API:
+ *
+ * kmap() API provides sleep semantics hence referred to as "permanent maps"
+ * It allows mapping LAST_PKMAP pages, using @last_pkmap_nr as the cursor
+ * for book-keeping
+ *
+ * kmap_atomic() can't sleep (calls pagefault_disable()), thus it provides
+ * shortlived ala "temporary mappings" which historically were implemented as
+ * fixmaps (compile time addr etc). Their book-keeping is done per cpu.
+ *
+ *	Both these facts combined (preemption disabled and per-cpu allocation)
+ *	means the total number of concurrent fixmaps will be limited to max
+ *	such allocations in a single control path. Thus KM_TYPE_NR (another
+ *	historic relic) is a small'ish number which caps max percpu fixmaps
+ *
+ * ARC HIGHMEM Details
+ *
+ * - the kernel vaddr space from 0x7z to 0x8z (currently used by vmalloc/module)
+ *   is now shared between vmalloc and kmap (non overlapping though)
+ *
+ * - Both fixmap/pkmap use a dedicated page table each, hooked up to swapper PGD
+ *   This means each only has 1 PGDIR_SIZE worth of kvaddr mappings, which means
+ *   2M of kvaddr space for typical config (8K page and 11:8:13 traversal split)
+ *
+ * - fixmap anyhow needs a limited number of mappings. So 2M kvaddr == 256 PTE
+ *   slots across NR_CPUS would be more than sufficient (generic code defines
+ *   KM_TYPE_NR as 20).
+ *
+ * - pkmap being preemptible, in theory could do with more than 256 concurrent
+ *   mappings. However, generic pkmap code: map_new_virtual(), doesn't traverse
+ *   the PGD and only works with a single page table @pkmap_page_table, hence
+ *   sets the limit
+ */
+
+extern pte_t * pkmap_page_table;
+static pte_t * fixmap_page_table;
+
+void *kmap(struct page *page)
+{
+	BUG_ON(in_interrupt());
+	if (!PageHighMem(page))
+		return page_address(page);
+
+	return kmap_high(page);
+}
+EXPORT_SYMBOL(kmap);
+
+void *kmap_atomic(struct page *page)
+{
+	int idx, cpu_idx;
+	unsigned long vaddr;
+
+	preempt_disable();
+	pagefault_disable();
+	if (!PageHighMem(page))
+		return page_address(page);
+
+	cpu_idx = kmap_atomic_idx_push();
+	idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
+	vaddr = FIXMAP_ADDR(idx);
+
+	set_pte_at(&init_mm, vaddr, fixmap_page_table + idx,
+		   mk_pte(page, kmap_prot));
+
+	return (void *)vaddr;
+}
+EXPORT_SYMBOL(kmap_atomic);
+
+void __kunmap_atomic(void *kv)
+{
+	unsigned long kvaddr = (unsigned long)kv;
+
+	if (kvaddr >= FIXMAP_BASE && kvaddr < (FIXMAP_BASE + FIXMAP_SIZE)) {
+
+		/*
+		 * Because preemption is disabled, this vaddr can be associated
+		 * with the current allocated index.
+		 * But in case of multiple live kmap_atomic(), it still relies on
+		 * callers to unmap in right order.
+		 */
+		int cpu_idx = kmap_atomic_idx();
+		int idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
+
+		WARN_ON(kvaddr != FIXMAP_ADDR(idx));
+
+		pte_clear(&init_mm, kvaddr, fixmap_page_table + idx);
+		local_flush_tlb_kernel_range(kvaddr, kvaddr + PAGE_SIZE);
+
+		kmap_atomic_idx_pop();
+	}
+
+	pagefault_enable();
+	preempt_enable();
+}
+EXPORT_SYMBOL(__kunmap_atomic);
+
+static noinline pte_t * __init alloc_kmap_pgtable(unsigned long kvaddr)
+{
+	pgd_t *pgd_k;
+	pud_t *pud_k;
+	pmd_t *pmd_k;
+	pte_t *pte_k;
+
+	pgd_k = pgd_offset_k(kvaddr);
+	pud_k = pud_offset(pgd_k, kvaddr);
+	pmd_k = pmd_offset(pud_k, kvaddr);
+
+	pte_k = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
+	pmd_populate_kernel(&init_mm, pmd_k, pte_k);
+	return pte_k;
+}
+
+void __init kmap_init(void)
+{
+	/* Due to recursive include hell, we can't do this in processor.h */
+	BUILD_BUG_ON(PAGE_OFFSET < (VMALLOC_END + FIXMAP_SIZE + PKMAP_SIZE));
+
+	BUILD_BUG_ON(KM_TYPE_NR > PTRS_PER_PTE);
+	pkmap_page_table = alloc_kmap_pgtable(PKMAP_BASE);
+
+	BUILD_BUG_ON(LAST_PKMAP > PTRS_PER_PTE);
+	fixmap_page_table = alloc_kmap_pgtable(FIXMAP_BASE);
+}
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
new file mode 100644
index 000000000..f890b2f9f
--- /dev/null
+++ b/arch/arc/mm/init.c
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#ifdef CONFIG_BLK_DEV_INITRD
+#include <linux/initrd.h>
+#endif
+#include <linux/of_fdt.h>
+#include <linux/swap.h>
+#include <linux/module.h>
+#include <linux/highmem.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+#include <asm/arcregs.h>
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
+char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
+EXPORT_SYMBOL(empty_zero_page);
+
+static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
+static unsigned long low_mem_sz;
+
+#ifdef CONFIG_HIGHMEM
+static unsigned long min_high_pfn, max_high_pfn;
+static u64 high_mem_start;
+static u64 high_mem_sz;
+#endif
+
+#ifdef CONFIG_DISCONTIGMEM
+struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
+EXPORT_SYMBOL(node_data);
+#endif
+
+long __init arc_get_mem_sz(void)
+{
+	return low_mem_sz;
+}
+
+/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
+static int __init setup_mem_sz(char *str)
+{
+	low_mem_sz = memparse(str, NULL) & PAGE_MASK;
+
+	/* early console might not be setup yet - it will show up later */
+	pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
+
+	return 0;
+}
+early_param("mem", setup_mem_sz);
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+	int in_use = 0;
+
+	if (!low_mem_sz) {
+		if (base != low_mem_start)
+			panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
+
+		low_mem_sz = size;
+		in_use = 1;
+	} else {
+#ifdef CONFIG_HIGHMEM
+		high_mem_start = base;
+		high_mem_sz = size;
+		in_use = 1;
+#endif
+	}
+
+	pr_info("Memory @ %llx [%lldM] %s\n",
+		base, TO_MB(size), !in_use ? "Not used":"");
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+static int __init early_initrd(char *p)
+{
+	unsigned long start, size;
+	char *endp;
+
+	start = memparse(p, &endp);
+	if (*endp == ',') {
+		size = memparse(endp + 1, NULL);
+
+		initrd_start = (unsigned long)__va(start);
+		initrd_end = (unsigned long)__va(start + size);
+	}
+	return 0;
+}
+early_param("initrd", early_initrd);
+#endif
+
+/*
+ * First memory setup routine called from setup_arch()
+ * 1. setup swapper's mm @init_mm
+ * 2. Count the pages we have and setup bootmem allocator
+ * 3. zone setup
+ */
+void __init setup_arch_memory(void)
+{
+	unsigned long zones_size[MAX_NR_ZONES];
+	unsigned long zones_holes[MAX_NR_ZONES];
+
+	init_mm.start_code = (unsigned long)_text;
+	init_mm.end_code = (unsigned long)_etext;
+	init_mm.end_data = (unsigned long)_edata;
+	init_mm.brk = (unsigned long)_end;
+
+	/* first page of system - kernel .vector starts here */
+	min_low_pfn = ARCH_PFN_OFFSET;
+
+	/* Last usable page of low mem */
+	max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
+
+#ifdef CONFIG_FLATMEM
+	/* pfn_valid() uses this */
+	max_mapnr = max_low_pfn - min_low_pfn;
+#endif
+
+	/*------------- bootmem allocator setup -----------------------*/
+
+	/*
+	 * seed the bootmem allocator after any DT memory node parsing or
+	 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
+	 *
+	 * Only low mem is added, otherwise we have crashes when allocating
+	 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
+	 * avail memory, ending in highmem with a > 32-bit address. However
+	 * it then tries to memset it with a truncaed 32-bit handle, causing
+	 * the crash
+	 */
+
+	memblock_add_node(low_mem_start, low_mem_sz, 0);
+	memblock_reserve(CONFIG_LINUX_LINK_BASE,
+			 __pa(_end) - CONFIG_LINUX_LINK_BASE);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (initrd_start)
+		memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
+#endif
+
+	early_init_fdt_reserve_self();
+	early_init_fdt_scan_reserved_mem();
+
+	memblock_dump_all();
+
+	/*----------------- node/zones setup --------------------------*/
+	memset(zones_size, 0, sizeof(zones_size));
+	memset(zones_holes, 0, sizeof(zones_holes));
+
+	zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
+	zones_holes[ZONE_NORMAL] = 0;
+
+	/*
+	 * We can't use the helper free_area_init(zones[]) because it uses
+	 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
+	 * when our kernel doesn't start at PAGE_OFFSET, i.e.
+	 * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE
+	 */
+	free_area_init_node(0,			/* node-id */
+			    zones_size,		/* num pages per zone */
+			    min_low_pfn,	/* first pfn of node */
+			    zones_holes);	/* holes */
+
+#ifdef CONFIG_HIGHMEM
+	/*
+	 * Populate a new node with highmem
+	 *
+	 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
+	 * than addresses in normal ala low memory (0x8000_0000 based).
+	 * Even with PAE, the huge peripheral space hole would waste a lot of
+	 * mem with single mem_map[]. This warrants a mem_map per region design.
+	 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
+	 *
+	 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
+	 * populated with normal memory zone while node 1 only has highmem
+	 */
+	node_set_online(1);
+
+	min_high_pfn = PFN_DOWN(high_mem_start);
+	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
+
+	zones_size[ZONE_NORMAL] = 0;
+	zones_holes[ZONE_NORMAL] = 0;
+
+	zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;
+	zones_holes[ZONE_HIGHMEM] = 0;
+
+	free_area_init_node(1,			/* node-id */
+			    zones_size,		/* num pages per zone */
+			    min_high_pfn,	/* first pfn of node */
+			    zones_holes);	/* holes */
+
+	high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
+	kmap_init();
+#endif
+}
+
+/*
+ * mem_init - initializes memory
+ *
+ * Frees up bootmem
+ * Calculates and displays memory available/used
+ */
+void __init mem_init(void)
+{
+#ifdef CONFIG_HIGHMEM
+	unsigned long tmp;
+
+	reset_all_zones_managed_pages();
+	for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
+		free_highmem_page(pfn_to_page(tmp));
+#endif
+
+	free_all_bootmem();
+	mem_init_print_info(NULL);
+}
+
+/*
+ * free_initmem: Free all the __init memory.
+ */
+void __ref free_initmem(void)
+{
+	free_initmem_default(-1);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+#endif
diff --git a/arch/arc/mm/ioremap.c b/arch/arc/mm/ioremap.c
new file mode 100644
index 000000000..9881bd740
--- /dev/null
+++ b/arch/arc/mm/ioremap.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/cache.h>
+
+static inline bool arc_uncached_addr_space(phys_addr_t paddr)
+{
+	if (is_isa_arcompact()) {
+		if (paddr >= ARC_UNCACHED_ADDR_SPACE)
+			return true;
+	} else if (paddr >= perip_base && paddr <= perip_end) {
+		return true;
+	}
+
+	return false;
+}
+
+void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
+{
+	phys_addr_t end;
+
+	/* Don't allow wraparound or zero size */
+	end = paddr + size - 1;
+	if (!size || (end < paddr))
+		return NULL;
+
+	/*
+	 * If the region is h/w uncached, MMU mapping can be elided as optim
+	 * The cast to u32 is fine as this region can only be inside 4GB
+	 */
+	if (arc_uncached_addr_space(paddr))
+		return (void __iomem *)(u32)paddr;
+
+	return ioremap_prot(paddr, size, PAGE_KERNEL_NO_CACHE);
+}
+EXPORT_SYMBOL(ioremap);
+
+/*
+ * ioremap with access flags
+ * Cache semantics wise it is same as ioremap - "forced" uncached.
+ * However unlike vanilla ioremap which bypasses ARC MMU for addresses in
+ * ARC hardware uncached region, this one still goes thru the MMU as caller
+ * might need finer access control (R/W/X)
+ */
+void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
+			   unsigned long flags)
+{
+	unsigned long vaddr;
+	struct vm_struct *area;
+	phys_addr_t off, end;
+	pgprot_t prot = __pgprot(flags);
+
+	/* Don't allow wraparound, zero size */
+	end = paddr + size - 1;
+	if ((!size) || (end < paddr))
+		return NULL;
+
+	/* An early platform driver might end up here */
+	if (!slab_is_available())
+		return NULL;
+
+	/* force uncached */
+	prot = pgprot_noncached(prot);
+
+	/* Mappings have to be page-aligned */
+	off = paddr & ~PAGE_MASK;
+	paddr &= PAGE_MASK;
+	size = PAGE_ALIGN(end + 1) - paddr;
+
+	/*
+	 * Ok, go for it..
+	 */
+	area = get_vm_area(size, VM_IOREMAP);
+	if (!area)
+		return NULL;
+	area->phys_addr = paddr;
+	vaddr = (unsigned long)area->addr;
+	if (ioremap_page_range(vaddr, vaddr + size, paddr, prot)) {
+		vunmap((void __force *)vaddr);
+		return NULL;
+	}
+	return (void __iomem *)(off + (char __iomem *)vaddr);
+}
+EXPORT_SYMBOL(ioremap_prot);
+
+
+void iounmap(const void __iomem *addr)
+{
+	/* weird double cast to handle phys_addr_t > 32 bits */
+	if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
+		return;
+
+	vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
+}
+EXPORT_SYMBOL(iounmap);
diff --git a/arch/arc/mm/mmap.c b/arch/arc/mm/mmap.c
new file mode 100644
index 000000000..2e13683df
--- /dev/null
+++ b/arch/arc/mm/mmap.c
@@ -0,0 +1,79 @@
+/*
+ * ARC700 mmap
+ *
+ * (started from arm version - for VIPT alias handling)
+ *
+ * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/sched/mm.h>
+
+#include <asm/cacheflush.h>
+
+#define COLOUR_ALIGN(addr, pgoff)			\
+	((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) +	\
+	 (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
+
+/*
+ * 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.
+ */
+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;
+	int aliasing = cache_is_vipt_aliasing();
+	struct vm_unmapped_area_info info;
+
+	/*
+	 * We only need to do colour alignment if D cache aliases.
+	 */
+	if (aliasing)
+		do_align = filp || (flags & MAP_SHARED);
+
+	/*
+	 * We enforce the MAP_FIXED case.
+	 */
+	if (flags & MAP_FIXED) {
+		if (aliasing && 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/arc/mm/tlb.c b/arch/arc/mm/tlb.c
new file mode 100644
index 000000000..fa18c00b0
--- /dev/null
+++ b/arch/arc/mm/tlb.c
@@ -0,0 +1,1008 @@
+/*
+ * TLB Management (flush/create/diagnostics) for ARC700
+ *
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * vineetg: Aug 2011
+ *  -Reintroduce duplicate PD fixup - some customer chips still have the issue
+ *
+ * vineetg: May 2011
+ *  -No need to flush_cache_page( ) for each call to update_mmu_cache()
+ *   some of the LMBench tests improved amazingly
+ *      = page-fault thrice as fast (75 usec to 28 usec)
+ *      = mmap twice as fast (9.6 msec to 4.6 msec),
+ *      = fork (5.3 msec to 3.7 msec)
+ *
+ * vineetg: April 2011 :
+ *  -MMU v3: PD{0,1} bits layout changed: They don't overlap anymore,
+ *      helps avoid a shift when preparing PD0 from PTE
+ *
+ * vineetg: April 2011 : Preparing for MMU V3
+ *  -MMU v2/v3 BCRs decoded differently
+ *  -Remove TLB_SIZE hardcoding as it's variable now: 256 or 512
+ *  -tlb_entry_erase( ) can be void
+ *  -local_flush_tlb_range( ):
+ *      = need not "ceil" @end
+ *      = walks MMU only if range spans < 32 entries, as opposed to 256
+ *
+ * Vineetg: Sept 10th 2008
+ *  -Changes related to MMU v2 (Rel 4.8)
+ *
+ * Vineetg: Aug 29th 2008
+ *  -In TLB Flush operations (Metal Fix MMU) there is a explict command to
+ *    flush Micro-TLBS. If TLB Index Reg is invalid prior to TLBIVUTLB cmd,
+ *    it fails. Thus need to load it with ANY valid value before invoking
+ *    TLBIVUTLB cmd
+ *
+ * Vineetg: Aug 21th 2008:
+ *  -Reduced the duration of IRQ lockouts in TLB Flush routines
+ *  -Multiple copies of TLB erase code seperated into a "single" function
+ *  -In TLB Flush routines, interrupt disabling moved UP to retrieve ASID
+ *       in interrupt-safe region.
+ *
+ * Vineetg: April 23rd Bug #93131
+ *    Problem: tlb_flush_kernel_range() doesn't do anything if the range to
+ *              flush is more than the size of TLB itself.
+ *
+ * Rahul Trivedi : Codito Technologies 2004
+ */
+
+#include <linux/module.h>
+#include <linux/bug.h>
+#include <linux/mm_types.h>
+
+#include <asm/arcregs.h>
+#include <asm/setup.h>
+#include <asm/mmu_context.h>
+#include <asm/mmu.h>
+
+/*			Need for ARC MMU v2
+ *
+ * ARC700 MMU-v1 had a Joint-TLB for Code and Data and is 2 way set-assoc.
+ * For a memcpy operation with 3 players (src/dst/code) such that all 3 pages
+ * map into same set, there would be contention for the 2 ways causing severe
+ * Thrashing.
+ *
+ * Although J-TLB is 2 way set assoc, ARC700 caches J-TLB into uTLBS which has
+ * much higher associativity. u-D-TLB is 8 ways, u-I-TLB is 4 ways.
+ * Given this, the thrasing problem should never happen because once the 3
+ * J-TLB entries are created (even though 3rd will knock out one of the prev
+ * two), the u-D-TLB and u-I-TLB will have what is required to accomplish memcpy
+ *
+ * Yet we still see the Thrashing because a J-TLB Write cause flush of u-TLBs.
+ * This is a simple design for keeping them in sync. So what do we do?
+ * The solution which James came up was pretty neat. It utilised the assoc
+ * of uTLBs by not invalidating always but only when absolutely necessary.
+ *
+ * - Existing TLB commands work as before
+ * - New command (TLBWriteNI) for TLB write without clearing uTLBs
+ * - New command (TLBIVUTLB) to invalidate uTLBs.
+ *
+ * The uTLBs need only be invalidated when pages are being removed from the
+ * OS page table. If a 'victim' TLB entry is being overwritten in the main TLB
+ * as a result of a miss, the removed entry is still allowed to exist in the
+ * uTLBs as it is still valid and present in the OS page table. This allows the
+ * full associativity of the uTLBs to hide the limited associativity of the main
+ * TLB.
+ *
+ * During a miss handler, the new "TLBWriteNI" command is used to load
+ * entries without clearing the uTLBs.
+ *
+ * When the OS page table is updated, TLB entries that may be associated with a
+ * removed page are removed (flushed) from the TLB using TLBWrite. In this
+ * circumstance, the uTLBs must also be cleared. This is done by using the
+ * existing TLBWrite command. An explicit IVUTLB is also required for those
+ * corner cases when TLBWrite was not executed at all because the corresp
+ * J-TLB entry got evicted/replaced.
+ */
+
+
+/* A copy of the ASID from the PID reg is kept in asid_cache */
+DEFINE_PER_CPU(unsigned int, asid_cache) = MM_CTXT_FIRST_CYCLE;
+
+static int __read_mostly pae_exists;
+
+/*
+ * Utility Routine to erase a J-TLB entry
+ * Caller needs to setup Index Reg (manually or via getIndex)
+ */
+static inline void __tlb_entry_erase(void)
+{
+	write_aux_reg(ARC_REG_TLBPD1, 0);
+
+	if (is_pae40_enabled())
+		write_aux_reg(ARC_REG_TLBPD1HI, 0);
+
+	write_aux_reg(ARC_REG_TLBPD0, 0);
+	write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite);
+}
+
+#if (CONFIG_ARC_MMU_VER < 4)
+
+static inline unsigned int tlb_entry_lkup(unsigned long vaddr_n_asid)
+{
+	unsigned int idx;
+
+	write_aux_reg(ARC_REG_TLBPD0, vaddr_n_asid);
+
+	write_aux_reg(ARC_REG_TLBCOMMAND, TLBProbe);
+	idx = read_aux_reg(ARC_REG_TLBINDEX);
+
+	return idx;
+}
+
+static void tlb_entry_erase(unsigned int vaddr_n_asid)
+{
+	unsigned int idx;
+
+	/* Locate the TLB entry for this vaddr + ASID */
+	idx = tlb_entry_lkup(vaddr_n_asid);
+
+	/* No error means entry found, zero it out */
+	if (likely(!(idx & TLB_LKUP_ERR))) {
+		__tlb_entry_erase();
+	} else {
+		/* Duplicate entry error */
+		WARN(idx == TLB_DUP_ERR, "Probe returned Dup PD for %x\n",
+					   vaddr_n_asid);
+	}
+}
+
+/****************************************************************************
+ * ARC700 MMU caches recently used J-TLB entries (RAM) as uTLBs (FLOPs)
+ *
+ * New IVUTLB cmd in MMU v2 explictly invalidates the uTLB
+ *
+ * utlb_invalidate ( )
+ *  -For v2 MMU calls Flush uTLB Cmd
+ *  -For v1 MMU does nothing (except for Metal Fix v1 MMU)
+ *      This is because in v1 TLBWrite itself invalidate uTLBs
+ ***************************************************************************/
+
+static void utlb_invalidate(void)
+{
+#if (CONFIG_ARC_MMU_VER >= 2)
+
+#if (CONFIG_ARC_MMU_VER == 2)
+	/* MMU v2 introduced the uTLB Flush command.
+	 * There was however an obscure hardware bug, where uTLB flush would
+	 * fail when a prior probe for J-TLB (both totally unrelated) would
+	 * return lkup err - because the entry didn't exist in MMU.
+	 * The Workround was to set Index reg with some valid value, prior to
+	 * flush. This was fixed in MMU v3 hence not needed any more
+	 */
+	unsigned int idx;
+
+	/* make sure INDEX Reg is valid */
+	idx = read_aux_reg(ARC_REG_TLBINDEX);
+
+	/* If not write some dummy val */
+	if (unlikely(idx & TLB_LKUP_ERR))
+		write_aux_reg(ARC_REG_TLBINDEX, 0xa);
+#endif
+
+	write_aux_reg(ARC_REG_TLBCOMMAND, TLBIVUTLB);
+#endif
+
+}
+
+static void tlb_entry_insert(unsigned int pd0, pte_t pd1)
+{
+	unsigned int idx;
+
+	/*
+	 * First verify if entry for this vaddr+ASID already exists
+	 * This also sets up PD0 (vaddr, ASID..) for final commit
+	 */
+	idx = tlb_entry_lkup(pd0);
+
+	/*
+	 * If Not already present get a free slot from MMU.
+	 * Otherwise, Probe would have located the entry and set INDEX Reg
+	 * with existing location. This will cause Write CMD to over-write
+	 * existing entry with new PD0 and PD1
+	 */
+	if (likely(idx & TLB_LKUP_ERR))
+		write_aux_reg(ARC_REG_TLBCOMMAND, TLBGetIndex);
+
+	/* setup the other half of TLB entry (pfn, rwx..) */
+	write_aux_reg(ARC_REG_TLBPD1, pd1);
+
+	/*
+	 * Commit the Entry to MMU
+	 * It doesn't sound safe to use the TLBWriteNI cmd here
+	 * which doesn't flush uTLBs. I'd rather be safe than sorry.
+	 */
+	write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite);
+}
+
+#else	/* CONFIG_ARC_MMU_VER >= 4) */
+
+static void utlb_invalidate(void)
+{
+	/* No need since uTLB is always in sync with JTLB */
+}
+
+static void tlb_entry_erase(unsigned int vaddr_n_asid)
+{
+	write_aux_reg(ARC_REG_TLBPD0, vaddr_n_asid | _PAGE_PRESENT);
+	write_aux_reg(ARC_REG_TLBCOMMAND, TLBDeleteEntry);
+}
+
+static void tlb_entry_insert(unsigned int pd0, pte_t pd1)
+{
+	write_aux_reg(ARC_REG_TLBPD0, pd0);
+	write_aux_reg(ARC_REG_TLBPD1, pd1);
+
+	if (is_pae40_enabled())
+		write_aux_reg(ARC_REG_TLBPD1HI, (u64)pd1 >> 32);
+
+	write_aux_reg(ARC_REG_TLBCOMMAND, TLBInsertEntry);
+}
+
+#endif
+
+/*
+ * Un-conditionally (without lookup) erase the entire MMU contents
+ */
+
+noinline void local_flush_tlb_all(void)
+{
+	struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
+	unsigned long flags;
+	unsigned int entry;
+	int num_tlb = mmu->sets * mmu->ways;
+
+	local_irq_save(flags);
+
+	/* Load PD0 and PD1 with template for a Blank Entry */
+	write_aux_reg(ARC_REG_TLBPD1, 0);
+
+	if (is_pae40_enabled())
+		write_aux_reg(ARC_REG_TLBPD1HI, 0);
+
+	write_aux_reg(ARC_REG_TLBPD0, 0);
+
+	for (entry = 0; entry < num_tlb; entry++) {
+		/* write this entry to the TLB */
+		write_aux_reg(ARC_REG_TLBINDEX, entry);
+		write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite);
+	}
+
+	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
+		const int stlb_idx = 0x800;
+
+		/* Blank sTLB entry */
+		write_aux_reg(ARC_REG_TLBPD0, _PAGE_HW_SZ);
+
+		for (entry = stlb_idx; entry < stlb_idx + 16; entry++) {
+			write_aux_reg(ARC_REG_TLBINDEX, entry);
+			write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite);
+		}
+	}
+
+	utlb_invalidate();
+
+	local_irq_restore(flags);
+}
+
+/*
+ * Flush the entrie MM for userland. The fastest way is to move to Next ASID
+ */
+noinline void local_flush_tlb_mm(struct mm_struct *mm)
+{
+	/*
+	 * Small optimisation courtesy IA64
+	 * flush_mm called during fork,exit,munmap etc, multiple times as well.
+	 * Only for fork( ) do we need to move parent to a new MMU ctxt,
+	 * all other cases are NOPs, hence this check.
+	 */
+	if (atomic_read(&mm->mm_users) == 0)
+		return;
+
+	/*
+	 * - Move to a new ASID, but only if the mm is still wired in
+	 *   (Android Binder ended up calling this for vma->mm != tsk->mm,
+	 *    causing h/w - s/w ASID to get out of sync)
+	 * - Also get_new_mmu_context() new implementation allocates a new
+	 *   ASID only if it is not allocated already - so unallocate first
+	 */
+	destroy_context(mm);
+	if (current->mm == mm)
+		get_new_mmu_context(mm);
+}
+
+/*
+ * Flush a Range of TLB entries for userland.
+ * @start is inclusive, while @end is exclusive
+ * Difference between this and Kernel Range Flush is
+ *  -Here the fastest way (if range is too large) is to move to next ASID
+ *      without doing any explicit Shootdown
+ *  -In case of kernel Flush, entry has to be shot down explictly
+ */
+void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+			   unsigned long end)
+{
+	const unsigned int cpu = smp_processor_id();
+	unsigned long flags;
+
+	/* If range @start to @end is more than 32 TLB entries deep,
+	 * its better to move to a new ASID rather than searching for
+	 * individual entries and then shooting them down
+	 *
+	 * The calc above is rough, doesn't account for unaligned parts,
+	 * since this is heuristics based anyways
+	 */
+	if (unlikely((end - start) >= PAGE_SIZE * 32)) {
+		local_flush_tlb_mm(vma->vm_mm);
+		return;
+	}
+
+	/*
+	 * @start moved to page start: this alone suffices for checking
+	 * loop end condition below, w/o need for aligning @end to end
+	 * e.g. 2000 to 4001 will anyhow loop twice
+	 */
+	start &= PAGE_MASK;
+
+	local_irq_save(flags);
+
+	if (asid_mm(vma->vm_mm, cpu) != MM_CTXT_NO_ASID) {
+		while (start < end) {
+			tlb_entry_erase(start | hw_pid(vma->vm_mm, cpu));
+			start += PAGE_SIZE;
+		}
+	}
+
+	utlb_invalidate();
+
+	local_irq_restore(flags);
+}
+
+/* Flush the kernel TLB entries - vmalloc/modules (Global from MMU perspective)
+ *  @start, @end interpreted as kvaddr
+ * Interestingly, shared TLB entries can also be flushed using just
+ * @start,@end alone (interpreted as user vaddr), although technically SASID
+ * is also needed. However our smart TLbProbe lookup takes care of that.
+ */
+void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+	unsigned long flags;
+
+	/* exactly same as above, except for TLB entry not taking ASID */
+
+	if (unlikely((end - start) >= PAGE_SIZE * 32)) {
+		local_flush_tlb_all();
+		return;
+	}
+
+	start &= PAGE_MASK;
+
+	local_irq_save(flags);
+	while (start < end) {
+		tlb_entry_erase(start);
+		start += PAGE_SIZE;
+	}
+
+	utlb_invalidate();
+
+	local_irq_restore(flags);
+}
+
+/*
+ * Delete TLB entry in MMU for a given page (??? address)
+ * NOTE One TLB entry contains translation for single PAGE
+ */
+
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+	const unsigned int cpu = smp_processor_id();
+	unsigned long flags;
+
+	/* Note that it is critical that interrupts are DISABLED between
+	 * checking the ASID and using it flush the TLB entry
+	 */
+	local_irq_save(flags);
+
+	if (asid_mm(vma->vm_mm, cpu) != MM_CTXT_NO_ASID) {
+		tlb_entry_erase((page & PAGE_MASK) | hw_pid(vma->vm_mm, cpu));
+		utlb_invalidate();
+	}
+
+	local_irq_restore(flags);
+}
+
+#ifdef CONFIG_SMP
+
+struct tlb_args {
+	struct vm_area_struct *ta_vma;
+	unsigned long ta_start;
+	unsigned long ta_end;
+};
+
+static inline void ipi_flush_tlb_page(void *arg)
+{
+	struct tlb_args *ta = arg;
+
+	local_flush_tlb_page(ta->ta_vma, ta->ta_start);
+}
+
+static inline void ipi_flush_tlb_range(void *arg)
+{
+	struct tlb_args *ta = arg;
+
+	local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline void ipi_flush_pmd_tlb_range(void *arg)
+{
+	struct tlb_args *ta = arg;
+
+	local_flush_pmd_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
+}
+#endif
+
+static inline void ipi_flush_tlb_kernel_range(void *arg)
+{
+	struct tlb_args *ta = (struct tlb_args *)arg;
+
+	local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);
+}
+
+void flush_tlb_all(void)
+{
+	on_each_cpu((smp_call_func_t)local_flush_tlb_all, NULL, 1);
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+	on_each_cpu_mask(mm_cpumask(mm), (smp_call_func_t)local_flush_tlb_mm,
+			 mm, 1);
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
+{
+	struct tlb_args ta = {
+		.ta_vma = vma,
+		.ta_start = uaddr
+	};
+
+	on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_page, &ta, 1);
+}
+
+void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+		     unsigned long end)
+{
+	struct tlb_args ta = {
+		.ta_vma = vma,
+		.ta_start = start,
+		.ta_end = end
+	};
+
+	on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_range, &ta, 1);
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
+			 unsigned long end)
+{
+	struct tlb_args ta = {
+		.ta_vma = vma,
+		.ta_start = start,
+		.ta_end = end
+	};
+
+	on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_pmd_tlb_range, &ta, 1);
+}
+#endif
+
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+	struct tlb_args ta = {
+		.ta_start = start,
+		.ta_end = end
+	};
+
+	on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
+}
+#endif
+
+/*
+ * Routine to create a TLB entry
+ */
+void create_tlb(struct vm_area_struct *vma, unsigned long vaddr, pte_t *ptep)
+{
+	unsigned long flags;
+	unsigned int asid_or_sasid, rwx;
+	unsigned long pd0;
+	pte_t pd1;
+
+	/*
+	 * create_tlb() assumes that current->mm == vma->mm, since
+	 * -it ASID for TLB entry is fetched from MMU ASID reg (valid for curr)
+	 * -completes the lazy write to SASID reg (again valid for curr tsk)
+	 *
+	 * Removing the assumption involves
+	 * -Using vma->mm->context{ASID,SASID}, as opposed to MMU reg.
+	 * -Fix the TLB paranoid debug code to not trigger false negatives.
+	 * -More importantly it makes this handler inconsistent with fast-path
+	 *  TLB Refill handler which always deals with "current"
+	 *
+	 * Lets see the use cases when current->mm != vma->mm and we land here
+	 *  1. execve->copy_strings()->__get_user_pages->handle_mm_fault
+	 *     Here VM wants to pre-install a TLB entry for user stack while
+	 *     current->mm still points to pre-execve mm (hence the condition).
+	 *     However the stack vaddr is soon relocated (randomization) and
+	 *     move_page_tables() tries to undo that TLB entry.
+	 *     Thus not creating TLB entry is not any worse.
+	 *
+	 *  2. ptrace(POKETEXT) causes a CoW - debugger(current) inserting a
+	 *     breakpoint in debugged task. Not creating a TLB now is not
+	 *     performance critical.
+	 *
+	 * Both the cases above are not good enough for code churn.
+	 */
+	if (current->active_mm != vma->vm_mm)
+		return;
+
+	local_irq_save(flags);
+
+	tlb_paranoid_check(asid_mm(vma->vm_mm, smp_processor_id()), vaddr);
+
+	vaddr &= PAGE_MASK;
+
+	/* update this PTE credentials */
+	pte_val(*ptep) |= (_PAGE_PRESENT | _PAGE_ACCESSED);
+
+	/* Create HW TLB(PD0,PD1) from PTE  */
+
+	/* ASID for this task */
+	asid_or_sasid = read_aux_reg(ARC_REG_PID) & 0xff;
+
+	pd0 = vaddr | asid_or_sasid | (pte_val(*ptep) & PTE_BITS_IN_PD0);
+
+	/*
+	 * ARC MMU provides fully orthogonal access bits for K/U mode,
+	 * however Linux only saves 1 set to save PTE real-estate
+	 * Here we convert 3 PTE bits into 6 MMU bits:
+	 * -Kernel only entries have Kr Kw Kx 0 0 0
+	 * -User entries have mirrored K and U bits
+	 */
+	rwx = pte_val(*ptep) & PTE_BITS_RWX;
+
+	if (pte_val(*ptep) & _PAGE_GLOBAL)
+		rwx <<= 3;		/* r w x => Kr Kw Kx 0 0 0 */
+	else
+		rwx |= (rwx << 3);	/* r w x => Kr Kw Kx Ur Uw Ux */
+
+	pd1 = rwx | (pte_val(*ptep) & PTE_BITS_NON_RWX_IN_PD1);
+
+	tlb_entry_insert(pd0, pd1);
+
+	local_irq_restore(flags);
+}
+
+/*
+ * Called at the end of pagefault, for a userspace mapped page
+ *  -pre-install the corresponding TLB entry into MMU
+ *  -Finalize the delayed D-cache flush of kernel mapping of page due to
+ *  	flush_dcache_page(), copy_user_page()
+ *
+ * Note that flush (when done) involves both WBACK - so physical page is
+ * in sync as well as INV - so any non-congruent aliases don't remain
+ */
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr_unaligned,
+		      pte_t *ptep)
+{
+	unsigned long vaddr = vaddr_unaligned & PAGE_MASK;
+	phys_addr_t paddr = pte_val(*ptep) & PAGE_MASK;
+	struct page *page = pfn_to_page(pte_pfn(*ptep));
+
+	create_tlb(vma, vaddr, ptep);
+
+	if (page == ZERO_PAGE(0)) {
+		return;
+	}
+
+	/*
+	 * Exec page : Independent of aliasing/page-color considerations,
+	 *	       since icache doesn't snoop dcache on ARC, any dirty
+	 *	       K-mapping of a code page needs to be wback+inv so that
+	 *	       icache fetch by userspace sees code correctly.
+	 * !EXEC page: If K-mapping is NOT congruent to U-mapping, flush it
+	 *	       so userspace sees the right data.
+	 *  (Avoids the flush for Non-exec + congruent mapping case)
+	 */
+	if ((vma->vm_flags & VM_EXEC) ||
+	     addr_not_cache_congruent(paddr, vaddr)) {
+
+		int dirty = !test_and_set_bit(PG_dc_clean, &page->flags);
+		if (dirty) {
+			/* wback + inv dcache lines (K-mapping) */
+			__flush_dcache_page(paddr, paddr);
+
+			/* invalidate any existing icache lines (U-mapping) */
+			if (vma->vm_flags & VM_EXEC)
+				__inv_icache_page(paddr, vaddr);
+		}
+	}
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+/*
+ * MMUv4 in HS38x cores supports Super Pages which are basis for Linux THP
+ * support.
+ *
+ * Normal and Super pages can co-exist (ofcourse not overlap) in TLB with a
+ * new bit "SZ" in TLB page descriptor to distinguish between them.
+ * Super Page size is configurable in hardware (4K to 16M), but fixed once
+ * RTL builds.
+ *
+ * The exact THP size a Linx configuration will support is a function of:
+ *  - MMU page size (typical 8K, RTL fixed)
+ *  - software page walker address split between PGD:PTE:PFN (typical
+ *    11:8:13, but can be changed with 1 line)
+ * So for above default, THP size supported is 8K * (2^8) = 2M
+ *
+ * Default Page Walker is 2 levels, PGD:PTE:PFN, which in THP regime
+ * reduces to 1 level (as PTE is folded into PGD and canonically referred
+ * to as PMD).
+ * Thus THP PMD accessors are implemented in terms of PTE (just like sparc)
+ */
+
+void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
+				 pmd_t *pmd)
+{
+	pte_t pte = __pte(pmd_val(*pmd));
+	update_mmu_cache(vma, addr, &pte);
+}
+
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				pgtable_t pgtable)
+{
+	struct list_head *lh = (struct list_head *) pgtable;
+
+	assert_spin_locked(&mm->page_table_lock);
+
+	/* FIFO */
+	if (!pmd_huge_pte(mm, pmdp))
+		INIT_LIST_HEAD(lh);
+	else
+		list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
+	pmd_huge_pte(mm, pmdp) = pgtable;
+}
+
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
+{
+	struct list_head *lh;
+	pgtable_t pgtable;
+
+	assert_spin_locked(&mm->page_table_lock);
+
+	pgtable = pmd_huge_pte(mm, pmdp);
+	lh = (struct list_head *) pgtable;
+	if (list_empty(lh))
+		pmd_huge_pte(mm, pmdp) = NULL;
+	else {
+		pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
+		list_del(lh);
+	}
+
+	pte_val(pgtable[0]) = 0;
+	pte_val(pgtable[1]) = 0;
+
+	return pgtable;
+}
+
+void local_flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
+			       unsigned long end)
+{
+	unsigned int cpu;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	cpu = smp_processor_id();
+
+	if (likely(asid_mm(vma->vm_mm, cpu) != MM_CTXT_NO_ASID)) {
+		unsigned int asid = hw_pid(vma->vm_mm, cpu);
+
+		/* No need to loop here: this will always be for 1 Huge Page */
+		tlb_entry_erase(start | _PAGE_HW_SZ | asid);
+	}
+
+	local_irq_restore(flags);
+}
+
+#endif
+
+/* Read the Cache Build Confuration Registers, Decode them and save into
+ * the cpuinfo structure for later use.
+ * No Validation is done here, simply read/convert the BCRs
+ */
+void read_decode_mmu_bcr(void)
+{
+	struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
+	unsigned int tmp;
+	struct bcr_mmu_1_2 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		unsigned int ver:8, ways:4, sets:4, u_itlb:8, u_dtlb:8;
+#else
+		unsigned int u_dtlb:8, u_itlb:8, sets:4, ways:4, ver:8;
+#endif
+	} *mmu2;
+
+	struct bcr_mmu_3 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	unsigned int ver:8, ways:4, sets:4, res:3, sasid:1, pg_sz:4,
+		     u_itlb:4, u_dtlb:4;
+#else
+	unsigned int u_dtlb:4, u_itlb:4, pg_sz:4, sasid:1, res:3, sets:4,
+		     ways:4, ver:8;
+#endif
+	} *mmu3;
+
+	struct bcr_mmu_4 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	unsigned int ver:8, sasid:1, sz1:4, sz0:4, res:2, pae:1,
+		     n_ways:2, n_entry:2, n_super:2, u_itlb:3, u_dtlb:3;
+#else
+	/*           DTLB      ITLB      JES        JE         JA      */
+	unsigned int u_dtlb:3, u_itlb:3, n_super:2, n_entry:2, n_ways:2,
+		     pae:1, res:2, sz0:4, sz1:4, sasid:1, ver:8;
+#endif
+	} *mmu4;
+
+	tmp = read_aux_reg(ARC_REG_MMU_BCR);
+	mmu->ver = (tmp >> 24);
+
+	if (is_isa_arcompact()) {
+		if (mmu->ver <= 2) {
+			mmu2 = (struct bcr_mmu_1_2 *)&tmp;
+			mmu->pg_sz_k = TO_KB(0x2000);
+			mmu->sets = 1 << mmu2->sets;
+			mmu->ways = 1 << mmu2->ways;
+			mmu->u_dtlb = mmu2->u_dtlb;
+			mmu->u_itlb = mmu2->u_itlb;
+		} else {
+			mmu3 = (struct bcr_mmu_3 *)&tmp;
+			mmu->pg_sz_k = 1 << (mmu3->pg_sz - 1);
+			mmu->sets = 1 << mmu3->sets;
+			mmu->ways = 1 << mmu3->ways;
+			mmu->u_dtlb = mmu3->u_dtlb;
+			mmu->u_itlb = mmu3->u_itlb;
+			mmu->sasid = mmu3->sasid;
+		}
+	} else {
+		mmu4 = (struct bcr_mmu_4 *)&tmp;
+		mmu->pg_sz_k = 1 << (mmu4->sz0 - 1);
+		mmu->s_pg_sz_m = 1 << (mmu4->sz1 - 11);
+		mmu->sets = 64 << mmu4->n_entry;
+		mmu->ways = mmu4->n_ways * 2;
+		mmu->u_dtlb = mmu4->u_dtlb * 4;
+		mmu->u_itlb = mmu4->u_itlb * 4;
+		mmu->sasid = mmu4->sasid;
+		pae_exists = mmu->pae = mmu4->pae;
+	}
+}
+
+char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len)
+{
+	int n = 0;
+	struct cpuinfo_arc_mmu *p_mmu = &cpuinfo_arc700[cpu_id].mmu;
+	char super_pg[64] = "";
+
+	if (p_mmu->s_pg_sz_m)
+		scnprintf(super_pg, 64, "%dM Super Page %s",
+			  p_mmu->s_pg_sz_m,
+			  IS_USED_CFG(CONFIG_TRANSPARENT_HUGEPAGE));
+
+	n += scnprintf(buf + n, len - n,
+		      "MMU [v%x]\t: %dk PAGE, %sJTLB %d (%dx%d), uDTLB %d, uITLB %d%s%s\n",
+		       p_mmu->ver, p_mmu->pg_sz_k, super_pg,
+		       p_mmu->sets * p_mmu->ways, p_mmu->sets, p_mmu->ways,
+		       p_mmu->u_dtlb, p_mmu->u_itlb,
+		       IS_AVAIL2(p_mmu->pae, ", PAE40 ", CONFIG_ARC_HAS_PAE40));
+
+	return buf;
+}
+
+int pae40_exist_but_not_enab(void)
+{
+	return pae_exists && !is_pae40_enabled();
+}
+
+void arc_mmu_init(void)
+{
+	struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
+	char str[256];
+	int compat = 0;
+
+	pr_info("%s", arc_mmu_mumbojumbo(0, str, sizeof(str)));
+
+	/*
+	 * Can't be done in processor.h due to header include depenedencies
+	 */
+	BUILD_BUG_ON(!IS_ALIGNED((CONFIG_ARC_KVADDR_SIZE << 20), PMD_SIZE));
+
+	/*
+	 * stack top size sanity check,
+	 * Can't be done in processor.h due to header include depenedencies
+	 */
+	BUILD_BUG_ON(!IS_ALIGNED(STACK_TOP, PMD_SIZE));
+
+	/*
+	 * Ensure that MMU features assumed by kernel exist in hardware.
+	 * For older ARC700 cpus, it has to be exact match, since the MMU
+	 * revisions were not backwards compatible (MMUv3 TLB layout changed
+	 * so even if kernel for v2 didn't use any new cmds of v3, it would
+	 * still not work.
+	 * For HS cpus, MMUv4 was baseline and v5 is backwards compatible
+	 * (will run older software).
+	 */
+	if (is_isa_arcompact() && mmu->ver == CONFIG_ARC_MMU_VER)
+		compat = 1;
+	else if (is_isa_arcv2() && mmu->ver >= CONFIG_ARC_MMU_VER)
+		compat = 1;
+
+	if (!compat) {
+		panic("MMU ver %d doesn't match kernel built for %d...\n",
+		      mmu->ver, CONFIG_ARC_MMU_VER);
+	}
+
+	if (mmu->pg_sz_k != TO_KB(PAGE_SIZE))
+		panic("MMU pg size != PAGE_SIZE (%luk)\n", TO_KB(PAGE_SIZE));
+
+	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
+	    mmu->s_pg_sz_m != TO_MB(HPAGE_PMD_SIZE))
+		panic("MMU Super pg size != Linux HPAGE_PMD_SIZE (%luM)\n",
+		      (unsigned long)TO_MB(HPAGE_PMD_SIZE));
+
+	if (IS_ENABLED(CONFIG_ARC_HAS_PAE40) && !mmu->pae)
+		panic("Hardware doesn't support PAE40\n");
+
+	/* Enable the MMU */
+	write_aux_reg(ARC_REG_PID, MMU_ENABLE);
+
+	/* In smp we use this reg for interrupt 1 scratch */
+#ifndef CONFIG_SMP
+	/* swapper_pg_dir is the pgd for the kernel, used by vmalloc */
+	write_aux_reg(ARC_REG_SCRATCH_DATA0, swapper_pg_dir);
+#endif
+
+	if (pae40_exist_but_not_enab())
+		write_aux_reg(ARC_REG_TLBPD1HI, 0);
+}
+
+/*
+ * TLB Programmer's Model uses Linear Indexes: 0 to {255, 511} for 128 x {2,4}
+ * The mapping is Column-first.
+ *		---------------------	-----------
+ *		|way0|way1|way2|way3|	|way0|way1|
+ *		---------------------	-----------
+ * [set0]	|  0 |  1 |  2 |  3 |	|  0 |  1 |
+ * [set1]	|  4 |  5 |  6 |  7 |	|  2 |  3 |
+ *		~		    ~	~	  ~
+ * [set127]	| 508| 509| 510| 511|	| 254| 255|
+ *		---------------------	-----------
+ * For normal operations we don't(must not) care how above works since
+ * MMU cmd getIndex(vaddr) abstracts that out.
+ * However for walking WAYS of a SET, we need to know this
+ */
+#define SET_WAY_TO_IDX(mmu, set, way)  ((set) * mmu->ways + (way))
+
+/* Handling of Duplicate PD (TLB entry) in MMU.
+ * -Could be due to buggy customer tapeouts or obscure kernel bugs
+ * -MMU complaints not at the time of duplicate PD installation, but at the
+ *      time of lookup matching multiple ways.
+ * -Ideally these should never happen - but if they do - workaround by deleting
+ *      the duplicate one.
+ * -Knob to be verbose abt it.(TODO: hook them up to debugfs)
+ */
+volatile int dup_pd_silent; /* Be slient abt it or complain (default) */
+
+void do_tlb_overlap_fault(unsigned long cause, unsigned long address,
+			  struct pt_regs *regs)
+{
+	struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
+	unsigned long flags;
+	int set, n_ways = mmu->ways;
+
+	n_ways = min(n_ways, 4);
+	BUG_ON(mmu->ways > 4);
+
+	local_irq_save(flags);
+
+	/* loop thru all sets of TLB */
+	for (set = 0; set < mmu->sets; set++) {
+
+		int is_valid, way;
+		unsigned int pd0[4];
+
+		/* read out all the ways of current set */
+		for (way = 0, is_valid = 0; way < n_ways; way++) {
+			write_aux_reg(ARC_REG_TLBINDEX,
+					  SET_WAY_TO_IDX(mmu, set, way));
+			write_aux_reg(ARC_REG_TLBCOMMAND, TLBRead);
+			pd0[way] = read_aux_reg(ARC_REG_TLBPD0);
+			is_valid |= pd0[way] & _PAGE_PRESENT;
+			pd0[way] &= PAGE_MASK;
+		}
+
+		/* If all the WAYS in SET are empty, skip to next SET */
+		if (!is_valid)
+			continue;
+
+		/* Scan the set for duplicate ways: needs a nested loop */
+		for (way = 0; way < n_ways - 1; way++) {
+
+			int n;
+
+			if (!pd0[way])
+				continue;
+
+			for (n = way + 1; n < n_ways; n++) {
+				if (pd0[way] != pd0[n])
+					continue;
+
+				if (!dup_pd_silent)
+					pr_info("Dup TLB PD0 %08x @ set %d ways %d,%d\n",
+						pd0[way], set, way, n);
+
+				/*
+				 * clear entry @way and not @n.
+				 * This is critical to our optimised loop
+				 */
+				pd0[way] = 0;
+				write_aux_reg(ARC_REG_TLBINDEX,
+						SET_WAY_TO_IDX(mmu, set, way));
+				__tlb_entry_erase();
+			}
+		}
+	}
+
+	local_irq_restore(flags);
+}
+
+/***********************************************************************
+ * Diagnostic Routines
+ *  -Called from Low Level TLB Hanlders if things don;t look good
+ **********************************************************************/
+
+#ifdef CONFIG_ARC_DBG_TLB_PARANOIA
+
+/*
+ * Low Level ASM TLB handler calls this if it finds that HW and SW ASIDS
+ * don't match
+ */
+void print_asid_mismatch(int mm_asid, int mmu_asid, int is_fast_path)
+{
+	pr_emerg("ASID Mismatch in %s Path Handler: sw-pid=0x%x hw-pid=0x%x\n",
+	       is_fast_path ? "Fast" : "Slow", mm_asid, mmu_asid);
+
+	__asm__ __volatile__("flag 1");
+}
+
+void tlb_paranoid_check(unsigned int mm_asid, unsigned long addr)
+{
+	unsigned int mmu_asid;
+
+	mmu_asid = read_aux_reg(ARC_REG_PID) & 0xff;
+
+	/*
+	 * At the time of a TLB miss/installation
+	 *   - HW version needs to match SW version
+	 *   - SW needs to have a valid ASID
+	 */
+	if (addr < 0x70000000 &&
+	    ((mm_asid == MM_CTXT_NO_ASID) ||
+	      (mmu_asid != (mm_asid & MM_CTXT_ASID_MASK))))
+		print_asid_mismatch(mm_asid, mmu_asid, 0);
+}
+#endif
diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S
new file mode 100644
index 000000000..0e1e47a67
--- /dev/null
+++ b/arch/arc/mm/tlbex.S
@@ -0,0 +1,405 @@
+/*
+ * TLB Exception Handling for ARC
+ *
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Vineetg: April 2011 :
+ *  -MMU v1: moved out legacy code into a seperate file
+ *  -MMU v3: PD{0,1} bits layout changed: They don't overlap anymore,
+ *      helps avoid a shift when preparing PD0 from PTE
+ *
+ * Vineetg: July 2009
+ *  -For MMU V2, we need not do heuristics at the time of commiting a D-TLB
+ *   entry, so that it doesn't knock out it's I-TLB entry
+ *  -Some more fine tuning:
+ *   bmsk instead of add, asl.cc instead of branch, delay slot utilise etc
+ *
+ * Vineetg: July 2009
+ *  -Practically rewrote the I/D TLB Miss handlers
+ *   Now 40 and 135 instructions a peice as compared to 131 and 449 resp.
+ *   Hence Leaner by 1.5 K
+ *   Used Conditional arithmetic to replace excessive branching
+ *   Also used short instructions wherever possible
+ *
+ * Vineetg: Aug 13th 2008
+ *  -Passing ECR (Exception Cause REG) to do_page_fault( ) for printing
+ *   more information in case of a Fatality
+ *
+ * Vineetg: March 25th Bug #92690
+ *  -Added Debug Code to check if sw-ASID == hw-ASID
+
+ * Rahul Trivedi, Amit Bhor: Codito Technologies 2004
+ */
+
+#include <linux/linkage.h>
+#include <asm/entry.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/arcregs.h>
+#include <asm/cache.h>
+#include <asm/processor.h>
+#include <asm/tlb-mmu1.h>
+
+#ifdef CONFIG_ISA_ARCOMPACT
+;-----------------------------------------------------------------
+; ARC700 Exception Handling doesn't auto-switch stack and it only provides
+; ONE scratch AUX reg "ARC_REG_SCRATCH_DATA0"
+;
+; For Non-SMP, the scratch AUX reg is repurposed to cache task PGD, so a
+; "global" is used to free-up FIRST core reg to be able to code the rest of
+; exception prologue (IRQ auto-disabled on Exceptions, so it's IRQ-safe).
+; Since the Fast Path TLB Miss handler is coded with 4 regs, the remaining 3
+; need to be saved as well by extending the "global" to be 4 words. Hence
+;	".size   ex_saved_reg1, 16"
+; [All of this dance is to avoid stack switching for each TLB Miss, since we
+; only need to save only a handful of regs, as opposed to complete reg file]
+;
+; For ARC700 SMP, the "global" obviously can't be used for free up the FIRST
+; core reg as it will not be SMP safe.
+; Thus scratch AUX reg is used (and no longer used to cache task PGD).
+; To save the rest of 3 regs - per cpu, the global is made "per-cpu".
+; Epilogue thus has to locate the "per-cpu" storage for regs.
+; To avoid cache line bouncing the per-cpu global is aligned/sized per
+; L1_CACHE_SHIFT, despite fundamentally needing to be 12 bytes only. Hence
+;	".size   ex_saved_reg1, (CONFIG_NR_CPUS << L1_CACHE_SHIFT)"
+
+; As simple as that....
+;--------------------------------------------------------------------------
+
+; scratch memory to save [r0-r3] used to code TLB refill Handler
+ARCFP_DATA ex_saved_reg1
+	.align 1 << L1_CACHE_SHIFT
+	.type   ex_saved_reg1, @object
+#ifdef CONFIG_SMP
+	.size   ex_saved_reg1, (CONFIG_NR_CPUS << L1_CACHE_SHIFT)
+ex_saved_reg1:
+	.zero (CONFIG_NR_CPUS << L1_CACHE_SHIFT)
+#else
+	.size   ex_saved_reg1, 16
+ex_saved_reg1:
+	.zero 16
+#endif
+
+.macro TLBMISS_FREEUP_REGS
+#ifdef CONFIG_SMP
+	sr  r0, [ARC_REG_SCRATCH_DATA0]	; freeup r0 to code with
+	GET_CPU_ID  r0			; get to per cpu scratch mem,
+	asl r0, r0, L1_CACHE_SHIFT	; cache line wide per cpu
+	add r0, @ex_saved_reg1, r0
+#else
+	st    r0, [@ex_saved_reg1]
+	mov_s r0, @ex_saved_reg1
+#endif
+	st_s  r1, [r0, 4]
+	st_s  r2, [r0, 8]
+	st_s  r3, [r0, 12]
+
+	; VERIFY if the ASID in MMU-PID Reg is same as
+	; one in Linux data structures
+
+	tlb_paranoid_check_asm
+.endm
+
+.macro TLBMISS_RESTORE_REGS
+#ifdef CONFIG_SMP
+	GET_CPU_ID  r0			; get to per cpu scratch mem
+	asl r0, r0, L1_CACHE_SHIFT	; each is cache line wide
+	add r0, @ex_saved_reg1, r0
+	ld_s  r3, [r0,12]
+	ld_s  r2, [r0, 8]
+	ld_s  r1, [r0, 4]
+	lr    r0, [ARC_REG_SCRATCH_DATA0]
+#else
+	mov_s r0, @ex_saved_reg1
+	ld_s  r3, [r0,12]
+	ld_s  r2, [r0, 8]
+	ld_s  r1, [r0, 4]
+	ld_s  r0, [r0]
+#endif
+.endm
+
+#else	/* ARCv2 */
+
+.macro TLBMISS_FREEUP_REGS
+	PUSH  r0
+	PUSH  r1
+	PUSH  r2
+	PUSH  r3
+.endm
+
+.macro TLBMISS_RESTORE_REGS
+	POP   r3
+	POP   r2
+	POP   r1
+	POP   r0
+.endm
+
+#endif
+
+;============================================================================
+;  Troubleshooting Stuff
+;============================================================================
+
+; Linux keeps ASID (Address Space ID) in task->active_mm->context.asid
+; When Creating TLB Entries, instead of doing 3 dependent loads from memory,
+; we use the MMU PID Reg to get current ASID.
+; In bizzare scenrios SW and HW ASID can get out-of-sync which is trouble.
+; So we try to detect this in TLB Mis shandler
+
+.macro tlb_paranoid_check_asm
+
+#ifdef CONFIG_ARC_DBG_TLB_PARANOIA
+
+	GET_CURR_TASK_ON_CPU  r3
+	ld r0, [r3, TASK_ACT_MM]
+	ld r0, [r0, MM_CTXT+MM_CTXT_ASID]
+	breq r0, 0, 55f	; Error if no ASID allocated
+
+	lr r1, [ARC_REG_PID]
+	and r1, r1, 0xFF
+
+	and r2, r0, 0xFF	; MMU PID bits only for comparison
+	breq r1, r2, 5f
+
+55:
+	; Error if H/w and S/w ASID don't match, but NOT if in kernel mode
+	lr  r2, [erstatus]
+	bbit0 r2, STATUS_U_BIT, 5f
+
+	; We sure are in troubled waters, Flag the error, but to do so
+	; need to switch to kernel mode stack to call error routine
+	GET_TSK_STACK_BASE   r3, sp
+
+	; Call printk to shoutout aloud
+	mov r2, 1
+	j print_asid_mismatch
+
+5:	; ASIDs match so proceed normally
+	nop
+
+#endif
+
+.endm
+
+;============================================================================
+;TLB Miss handling Code
+;============================================================================
+
+;-----------------------------------------------------------------------------
+; This macro does the page-table lookup for the faulting address.
+; OUT: r0 = PTE faulted on, r1 = ptr to PTE, r2 = Faulting V-address
+.macro LOAD_FAULT_PTE
+
+	lr  r2, [efa]
+
+#ifndef CONFIG_SMP
+	lr  r1, [ARC_REG_SCRATCH_DATA0] ; current pgd
+#else
+	GET_CURR_TASK_ON_CPU  r1
+	ld  r1, [r1, TASK_ACT_MM]
+	ld  r1, [r1, MM_PGD]
+#endif
+
+	lsr     r0, r2, PGDIR_SHIFT     ; Bits for indexing into PGD
+	ld.as   r3, [r1, r0]            ; PGD entry corresp to faulting addr
+	tst	r3, r3
+	bz	do_slow_path_pf         ; if no Page Table, do page fault
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	and.f	0, r3, _PAGE_HW_SZ	; Is this Huge PMD (thp)
+	add2.nz	r1, r1, r0
+	bnz.d	2f		; YES: PGD == PMD has THP PTE: stop pgd walk
+	mov.nz	r0, r3
+
+#endif
+	and	r1, r3, PAGE_MASK
+
+	; Get the PTE entry: The idea is
+	; (1) x = addr >> PAGE_SHIFT 	-> masks page-off bits from @fault-addr
+	; (2) y = x & (PTRS_PER_PTE - 1) -> to get index
+	; (3) z = (pgtbl + y * 4)
+
+#ifdef CONFIG_ARC_HAS_PAE40
+#define PTE_SIZE_LOG	3	/* 8 == 2 ^ 3 */
+#else
+#define PTE_SIZE_LOG	2	/* 4 == 2 ^ 2 */
+#endif
+
+	; multiply in step (3) above avoided by shifting lesser in step (1)
+	lsr     r0, r2, ( PAGE_SHIFT - PTE_SIZE_LOG )
+	and     r0, r0, ( (PTRS_PER_PTE - 1) << PTE_SIZE_LOG )
+	ld.aw   r0, [r1, r0]            ; r0: PTE (lower word only for PAE40)
+					; r1: PTE ptr
+
+2:
+
+.endm
+
+;-----------------------------------------------------------------
+; Convert Linux PTE entry into TLB entry
+; A one-word PTE entry is programmed as two-word TLB Entry [PD0:PD1] in mmu
+;    (for PAE40, two-words PTE, while three-word TLB Entry [PD0:PD1:PD1HI])
+; IN: r0 = PTE, r1 = ptr to PTE
+
+.macro CONV_PTE_TO_TLB
+	and    r3, r0, PTE_BITS_RWX	;          r  w  x
+	asl    r2, r3, 3		; Kr Kw Kx 0  0  0 (GLOBAL, kernel only)
+	and.f  0,  r0, _PAGE_GLOBAL
+	or.z   r2, r2, r3		; Kr Kw Kx Ur Uw Ux (!GLOBAL, user page)
+
+	and r3, r0, PTE_BITS_NON_RWX_IN_PD1 ; Extract PFN+cache bits from PTE
+	or  r3, r3, r2
+
+	sr  r3, [ARC_REG_TLBPD1]    	; paddr[31..13] | Kr Kw Kx Ur Uw Ux | C
+#ifdef	CONFIG_ARC_HAS_PAE40
+	ld	r3, [r1, 4]		; paddr[39..32]
+	sr	r3, [ARC_REG_TLBPD1HI]
+#endif
+
+	and r2, r0, PTE_BITS_IN_PD0 ; Extract other PTE flags: (V)alid, (G)lb
+
+	lr  r3,[ARC_REG_TLBPD0]     ; MMU prepares PD0 with vaddr and asid
+
+	or  r3, r3, r2              ; S | vaddr | {sasid|asid}
+	sr  r3,[ARC_REG_TLBPD0]     ; rewrite PD0
+.endm
+
+;-----------------------------------------------------------------
+; Commit the TLB entry into MMU
+
+.macro COMMIT_ENTRY_TO_MMU
+#if (CONFIG_ARC_MMU_VER < 4)
+
+#ifdef CONFIG_EZNPS_MTM_EXT
+	/* verify if entry for this vaddr+ASID already exists */
+	sr    TLBProbe, [ARC_REG_TLBCOMMAND]
+	lr    r0, [ARC_REG_TLBINDEX]
+	bbit0 r0, 31, 88f
+#endif
+
+	/* Get free TLB slot: Set = computed from vaddr, way = random */
+	sr  TLBGetIndex, [ARC_REG_TLBCOMMAND]
+
+	/* Commit the Write */
+#if (CONFIG_ARC_MMU_VER >= 2)   /* introduced in v2 */
+	sr TLBWriteNI, [ARC_REG_TLBCOMMAND]
+#else
+	sr TLBWrite, [ARC_REG_TLBCOMMAND]
+#endif
+
+#else
+	sr TLBInsertEntry, [ARC_REG_TLBCOMMAND]
+#endif
+
+88:
+.endm
+
+
+ARCFP_CODE	;Fast Path Code, candidate for ICCM
+
+;-----------------------------------------------------------------------------
+; I-TLB Miss Exception Handler
+;-----------------------------------------------------------------------------
+
+ENTRY(EV_TLBMissI)
+
+	TLBMISS_FREEUP_REGS
+
+	;----------------------------------------------------------------
+	; Get the PTE corresponding to V-addr accessed, r2 is setup with EFA
+	LOAD_FAULT_PTE
+
+	;----------------------------------------------------------------
+	; VERIFY_PTE: Check if PTE permissions approp for executing code
+	cmp_s   r2, VMALLOC_START
+	mov_s   r2, (_PAGE_PRESENT | _PAGE_EXECUTE)
+	or.hs   r2, r2, _PAGE_GLOBAL
+
+	and     r3, r0, r2  ; Mask out NON Flag bits from PTE
+	xor.f   r3, r3, r2  ; check ( ( pte & flags_test ) == flags_test )
+	bnz     do_slow_path_pf
+
+	; Let Linux VM know that the page was accessed
+	or      r0, r0, _PAGE_ACCESSED  ; set Accessed Bit
+	st_s    r0, [r1]                ; Write back PTE
+
+	CONV_PTE_TO_TLB
+	COMMIT_ENTRY_TO_MMU
+	TLBMISS_RESTORE_REGS
+EV_TLBMissI_fast_ret:	; additional label for VDK OS-kit instrumentation
+	rtie
+
+END(EV_TLBMissI)
+
+;-----------------------------------------------------------------------------
+; D-TLB Miss Exception Handler
+;-----------------------------------------------------------------------------
+
+ENTRY(EV_TLBMissD)
+
+	TLBMISS_FREEUP_REGS
+
+	;----------------------------------------------------------------
+	; Get the PTE corresponding to V-addr accessed
+	; If PTE exists, it will setup, r0 = PTE, r1 = Ptr to PTE, r2 = EFA
+	LOAD_FAULT_PTE
+
+	;----------------------------------------------------------------
+	; VERIFY_PTE: Chk if PTE permissions approp for data access (R/W/R+W)
+
+	cmp_s	r2, VMALLOC_START
+	mov_s   r2, _PAGE_PRESENT	; common bit for K/U PTE
+	or.hs	r2, r2, _PAGE_GLOBAL	; kernel PTE only
+
+	; Linux PTE [RWX] bits are semantically overloaded:
+	; -If PAGE_GLOBAL set, they refer to kernel-only flags (vmalloc)
+	; -Otherwise they are user-mode permissions, and those are exactly
+	;  same for kernel mode as well (e.g. copy_(to|from)_user)
+
+	lr      r3, [ecr]
+	btst_s  r3, ECR_C_BIT_DTLB_LD_MISS	; Read Access
+	or.nz   r2, r2, _PAGE_READ      	; chk for Read flag in PTE
+	btst_s  r3, ECR_C_BIT_DTLB_ST_MISS	; Write Access
+	or.nz   r2, r2, _PAGE_WRITE     	; chk for Write flag in PTE
+	; Above laddering takes care of XCHG access (both R and W)
+
+	; By now, r2 setup with all the Flags we need to check in PTE
+	and     r3, r0, r2              ; Mask out NON Flag bits from PTE
+	brne.d  r3, r2, do_slow_path_pf ; is ((pte & flags_test) == flags_test)
+
+	;----------------------------------------------------------------
+	; UPDATE_PTE: Let Linux VM know that page was accessed/dirty
+	lr      r3, [ecr]
+	or      r0, r0, _PAGE_ACCESSED        ; Accessed bit always
+	btst_s  r3,  ECR_C_BIT_DTLB_ST_MISS   ; See if it was a Write Access ?
+	or.nz   r0, r0, _PAGE_DIRTY           ; if Write, set Dirty bit as well
+	st_s    r0, [r1]                      ; Write back PTE
+
+	CONV_PTE_TO_TLB
+
+#if (CONFIG_ARC_MMU_VER == 1)
+	; MMU with 2 way set assoc J-TLB, needs some help in pathetic case of
+	; memcpy where 3 parties contend for 2 ways, ensuing a livelock.
+	; But only for old MMU or one with Metal Fix
+	TLB_WRITE_HEURISTICS
+#endif
+
+	COMMIT_ENTRY_TO_MMU
+	TLBMISS_RESTORE_REGS
+EV_TLBMissD_fast_ret:	; additional label for VDK OS-kit instrumentation
+	rtie
+
+;-------- Common routine to call Linux Page Fault Handler -----------
+do_slow_path_pf:
+
+	; Restore the 4-scratch regs saved by fast path miss handler
+	TLBMISS_RESTORE_REGS
+
+	; Slow path TLB Miss handled as a regular ARC Exception
+	; (stack switching / save the complete reg-file).
+	b  call_do_page_fault
+END(EV_TLBMissD)