v4.19.13 snapshot.
diff --git a/arch/nds32/mm/alignment.c b/arch/nds32/mm/alignment.c
new file mode 100644
index 0000000..e1aed9d
--- /dev/null
+++ b/arch/nds32/mm/alignment.c
@@ -0,0 +1,579 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/proc_fs.h>
+#include <linux/uaccess.h>
+#include <linux/sysctl.h>
+#include <asm/unaligned.h>
+
+#define DEBUG(enable, tagged, ...)				\
+	do{							\
+		if (enable) {					\
+			if (tagged)				\
+			pr_warn("[ %30s() ] ", __func__);	\
+			pr_warn(__VA_ARGS__);			\
+		}						\
+	} while (0)
+
+#define RT(inst)	(((inst) >> 20) & 0x1FUL)
+#define RA(inst)	(((inst) >> 15) & 0x1FUL)
+#define RB(inst)	(((inst) >> 10) & 0x1FUL)
+#define SV(inst)	(((inst) >> 8) & 0x3UL)
+#define IMM(inst)	(((inst) >> 0) & 0x7FFFUL)
+
+#define RA3(inst)	(((inst) >> 3) & 0x7UL)
+#define RT3(inst)	(((inst) >> 6) & 0x7UL)
+#define IMM3U(inst)	(((inst) >> 0) & 0x7UL)
+
+#define RA5(inst)	(((inst) >> 0) & 0x1FUL)
+#define RT4(inst)	(((inst) >> 5) & 0xFUL)
+
+#define GET_IMMSVAL(imm_value) \
+	(((imm_value >> 14) & 0x1) ? (imm_value - 0x8000) : imm_value)
+
+#define __get8_data(val,addr,err)	\
+	__asm__(					\
+	"1:	lbi.bi	%1, [%2], #1\n"			\
+	"2:\n"						\
+	"	.pushsection .text.fixup,\"ax\"\n"	\
+	"	.align	2\n"				\
+	"3:	movi	%0, #1\n"			\
+	"	j	2b\n"				\
+	"	.popsection\n"				\
+	"	.pushsection __ex_table,\"a\"\n"	\
+	"	.align	3\n"				\
+	"	.long	1b, 3b\n"			\
+	"	.popsection\n"				\
+	: "=r" (err), "=&r" (val), "=r" (addr)		\
+	: "0" (err), "2" (addr))
+
+#define get16_data(addr, val_ptr)				\
+	do {							\
+		unsigned int err = 0, v, a = addr;		\
+		__get8_data(v,a,err);				\
+		*val_ptr =  v << 0;				\
+		__get8_data(v,a,err);				\
+		*val_ptr |= v << 8;				\
+		if (err)					\
+			goto fault;				\
+		*val_ptr = le16_to_cpu(*val_ptr);		\
+	} while(0)
+
+#define get32_data(addr, val_ptr)				\
+	do {							\
+		unsigned int err = 0, v, a = addr;		\
+		__get8_data(v,a,err);				\
+		*val_ptr =  v << 0;				\
+		__get8_data(v,a,err);				\
+		*val_ptr |= v << 8;				\
+		__get8_data(v,a,err);				\
+		*val_ptr |= v << 16;				\
+		__get8_data(v,a,err);				\
+		*val_ptr |= v << 24;				\
+		if (err)					\
+			goto fault;				\
+		*val_ptr = le32_to_cpu(*val_ptr);		\
+	} while(0)
+
+#define get_data(addr, val_ptr, len)				\
+	if (len == 2)						\
+		get16_data(addr, val_ptr);			\
+	else							\
+		get32_data(addr, val_ptr);
+
+#define set16_data(addr, val)					\
+	do {							\
+		unsigned int err = 0, *ptr = addr ;		\
+		val = le32_to_cpu(val);				\
+		__asm__(					\
+                "1:	sbi.bi 	%2, [%1], #1\n"			\
+                "	srli 	%2, %2, #8\n"			\
+                "2:	sbi	%2, [%1]\n"			\
+		"3:\n"						\
+		"	.pushsection .text.fixup,\"ax\"\n"	\
+		"	.align	2\n"				\
+		"4:	movi	%0, #1\n"			\
+		"	j	3b\n"				\
+		"	.popsection\n"				\
+		"	.pushsection __ex_table,\"a\"\n"	\
+		"	.align	3\n"				\
+		"	.long	1b, 4b\n"			\
+		"	.long	2b, 4b\n"			\
+		"	.popsection\n"				\
+		: "=r" (err), "+r" (ptr), "+r" (val)		\
+		: "0" (err)					\
+		);						\
+		if (err)					\
+			goto fault;				\
+	} while(0)
+
+#define set32_data(addr, val)					\
+	do {							\
+		unsigned int err = 0, *ptr = addr ;		\
+		val = le32_to_cpu(val);				\
+		__asm__(					\
+                "1:	sbi.bi 	%2, [%1], #1\n"			\
+                "	srli 	%2, %2, #8\n"			\
+                "2:	sbi.bi 	%2, [%1], #1\n"			\
+                "	srli 	%2, %2, #8\n"			\
+                "3:	sbi.bi 	%2, [%1], #1\n"			\
+                "	srli 	%2, %2, #8\n"			\
+                "4:	sbi 	%2, [%1]\n"			\
+		"5:\n"						\
+		"	.pushsection .text.fixup,\"ax\"\n"	\
+		"	.align	2\n"				\
+		"6:	movi	%0, #1\n"			\
+		"	j	5b\n"				\
+		"	.popsection\n"				\
+		"	.pushsection __ex_table,\"a\"\n"	\
+		"	.align	3\n"				\
+		"	.long	1b, 6b\n"			\
+		"	.long	2b, 6b\n"			\
+		"	.long	3b, 6b\n"			\
+		"	.long	4b, 6b\n"			\
+		"	.popsection\n"				\
+		: "=r" (err), "+r" (ptr), "+r" (val)		\
+		: "0" (err)					\
+		);						\
+		if (err)					\
+			goto fault;				\
+	} while(0)
+#define set_data(addr, val, len)				\
+	if (len == 2)						\
+		set16_data(addr, val);				\
+	else							\
+		set32_data(addr, val);
+#define NDS32_16BIT_INSTRUCTION	0x80000000
+
+extern pte_t va_present(struct mm_struct *mm, unsigned long addr);
+extern pte_t va_kernel_present(unsigned long addr);
+extern int va_readable(struct pt_regs *regs, unsigned long addr);
+extern int va_writable(struct pt_regs *regs, unsigned long addr);
+
+int unalign_access_mode = 0, unalign_access_debug = 0;
+
+static inline unsigned long *idx_to_addr(struct pt_regs *regs, int idx)
+{
+	/* this should be consistent with ptrace.h */
+	if (idx >= 0 && idx <= 25)	/* R0-R25 */
+		return &regs->uregs[0] + idx;
+	else if (idx >= 28 && idx <= 30)	/* FP, GP, LP */
+		return &regs->fp + (idx - 28);
+	else if (idx == 31)	/* SP */
+		return &regs->sp;
+	else
+		return NULL;	/* cause a segfault */
+}
+
+static inline unsigned long get_inst(unsigned long addr)
+{
+	return be32_to_cpu(get_unaligned((u32 *) addr));
+}
+
+static inline unsigned long sign_extend(unsigned long val, int len)
+{
+	unsigned long ret = 0;
+	unsigned char *s, *t;
+	int i = 0;
+
+	val = cpu_to_le32(val);
+
+	s = (void *)&val;
+	t = (void *)&ret;
+
+	while (i++ < len)
+		*t++ = *s++;
+
+	if (((*(t - 1)) & 0x80) && (i < 4)) {
+
+		while (i++ <= 4)
+			*t++ = 0xff;
+	}
+
+	return le32_to_cpu(ret);
+}
+
+static inline int do_16(unsigned long inst, struct pt_regs *regs)
+{
+	int imm, regular, load, len, addr_mode, idx_mode;
+	unsigned long unaligned_addr, target_val, source_idx, target_idx,
+	    shift = 0;
+	switch ((inst >> 9) & 0x3F) {
+
+	case 0x12:		/* LHI333    */
+		imm = 1;
+		regular = 1;
+		load = 1;
+		len = 2;
+		addr_mode = 3;
+		idx_mode = 3;
+		break;
+	case 0x10:		/* LWI333    */
+		imm = 1;
+		regular = 1;
+		load = 1;
+		len = 4;
+		addr_mode = 3;
+		idx_mode = 3;
+		break;
+	case 0x11:		/* LWI333.bi */
+		imm = 1;
+		regular = 0;
+		load = 1;
+		len = 4;
+		addr_mode = 3;
+		idx_mode = 3;
+		break;
+	case 0x1A:		/* LWI450    */
+		imm = 0;
+		regular = 1;
+		load = 1;
+		len = 4;
+		addr_mode = 5;
+		idx_mode = 4;
+		break;
+	case 0x16:		/* SHI333    */
+		imm = 1;
+		regular = 1;
+		load = 0;
+		len = 2;
+		addr_mode = 3;
+		idx_mode = 3;
+		break;
+	case 0x14:		/* SWI333    */
+		imm = 1;
+		regular = 1;
+		load = 0;
+		len = 4;
+		addr_mode = 3;
+		idx_mode = 3;
+		break;
+	case 0x15:		/* SWI333.bi */
+		imm = 1;
+		regular = 0;
+		load = 0;
+		len = 4;
+		addr_mode = 3;
+		idx_mode = 3;
+		break;
+	case 0x1B:		/* SWI450    */
+		imm = 0;
+		regular = 1;
+		load = 0;
+		len = 4;
+		addr_mode = 5;
+		idx_mode = 4;
+		break;
+
+	default:
+		return -EFAULT;
+	}
+
+	if (addr_mode == 3) {
+		unaligned_addr = *idx_to_addr(regs, RA3(inst));
+		source_idx = RA3(inst);
+	} else {
+		unaligned_addr = *idx_to_addr(regs, RA5(inst));
+		source_idx = RA5(inst);
+	}
+
+	if (idx_mode == 3)
+		target_idx = RT3(inst);
+	else
+		target_idx = RT4(inst);
+
+	if (imm)
+		shift = IMM3U(inst) * len;
+
+	if (regular)
+		unaligned_addr += shift;
+
+	if (load) {
+		if (!access_ok(VERIFY_READ, (void *)unaligned_addr, len))
+			return -EACCES;
+
+		get_data(unaligned_addr, &target_val, len);
+		*idx_to_addr(regs, target_idx) = target_val;
+	} else {
+		if (!access_ok(VERIFY_WRITE, (void *)unaligned_addr, len))
+			return -EACCES;
+		target_val = *idx_to_addr(regs, target_idx);
+		set_data((void *)unaligned_addr, target_val, len);
+	}
+
+	if (!regular)
+		*idx_to_addr(regs, source_idx) = unaligned_addr + shift;
+	regs->ipc += 2;
+
+	return 0;
+fault:
+	return -EACCES;
+}
+
+static inline int do_32(unsigned long inst, struct pt_regs *regs)
+{
+	int imm, regular, load, len, sign_ext;
+	unsigned long unaligned_addr, target_val, shift;
+
+	unaligned_addr = *idx_to_addr(regs, RA(inst));
+
+	switch ((inst >> 25) << 1) {
+
+	case 0x02:		/* LHI       */
+		imm = 1;
+		regular = 1;
+		load = 1;
+		len = 2;
+		sign_ext = 0;
+		break;
+	case 0x0A:		/* LHI.bi    */
+		imm = 1;
+		regular = 0;
+		load = 1;
+		len = 2;
+		sign_ext = 0;
+		break;
+	case 0x22:		/* LHSI      */
+		imm = 1;
+		regular = 1;
+		load = 1;
+		len = 2;
+		sign_ext = 1;
+		break;
+	case 0x2A:		/* LHSI.bi   */
+		imm = 1;
+		regular = 0;
+		load = 1;
+		len = 2;
+		sign_ext = 1;
+		break;
+	case 0x04:		/* LWI       */
+		imm = 1;
+		regular = 1;
+		load = 1;
+		len = 4;
+		sign_ext = 0;
+		break;
+	case 0x0C:		/* LWI.bi    */
+		imm = 1;
+		regular = 0;
+		load = 1;
+		len = 4;
+		sign_ext = 0;
+		break;
+	case 0x12:		/* SHI       */
+		imm = 1;
+		regular = 1;
+		load = 0;
+		len = 2;
+		sign_ext = 0;
+		break;
+	case 0x1A:		/* SHI.bi    */
+		imm = 1;
+		regular = 0;
+		load = 0;
+		len = 2;
+		sign_ext = 0;
+		break;
+	case 0x14:		/* SWI       */
+		imm = 1;
+		regular = 1;
+		load = 0;
+		len = 4;
+		sign_ext = 0;
+		break;
+	case 0x1C:		/* SWI.bi    */
+		imm = 1;
+		regular = 0;
+		load = 0;
+		len = 4;
+		sign_ext = 0;
+		break;
+
+	default:
+		switch (inst & 0xff) {
+
+		case 0x01:	/* LH        */
+			imm = 0;
+			regular = 1;
+			load = 1;
+			len = 2;
+			sign_ext = 0;
+			break;
+		case 0x05:	/* LH.bi     */
+			imm = 0;
+			regular = 0;
+			load = 1;
+			len = 2;
+			sign_ext = 0;
+			break;
+		case 0x11:	/* LHS       */
+			imm = 0;
+			regular = 1;
+			load = 1;
+			len = 2;
+			sign_ext = 1;
+			break;
+		case 0x15:	/* LHS.bi    */
+			imm = 0;
+			regular = 0;
+			load = 1;
+			len = 2;
+			sign_ext = 1;
+			break;
+		case 0x02:	/* LW        */
+			imm = 0;
+			regular = 1;
+			load = 1;
+			len = 4;
+			sign_ext = 0;
+			break;
+		case 0x06:	/* LW.bi     */
+			imm = 0;
+			regular = 0;
+			load = 1;
+			len = 4;
+			sign_ext = 0;
+			break;
+		case 0x09:	/* SH        */
+			imm = 0;
+			regular = 1;
+			load = 0;
+			len = 2;
+			sign_ext = 0;
+			break;
+		case 0x0D:	/* SH.bi     */
+			imm = 0;
+			regular = 0;
+			load = 0;
+			len = 2;
+			sign_ext = 0;
+			break;
+		case 0x0A:	/* SW        */
+			imm = 0;
+			regular = 1;
+			load = 0;
+			len = 4;
+			sign_ext = 0;
+			break;
+		case 0x0E:	/* SW.bi     */
+			imm = 0;
+			regular = 0;
+			load = 0;
+			len = 4;
+			sign_ext = 0;
+			break;
+
+		default:
+			return -EFAULT;
+		}
+	}
+
+	if (imm)
+		shift = GET_IMMSVAL(IMM(inst)) * len;
+	else
+		shift = *idx_to_addr(regs, RB(inst)) << SV(inst);
+
+	if (regular)
+		unaligned_addr += shift;
+
+	if (load) {
+
+		if (!access_ok(VERIFY_READ, (void *)unaligned_addr, len))
+			return -EACCES;
+
+		get_data(unaligned_addr, &target_val, len);
+
+		if (sign_ext)
+			*idx_to_addr(regs, RT(inst)) =
+			    sign_extend(target_val, len);
+		else
+			*idx_to_addr(regs, RT(inst)) = target_val;
+	} else {
+
+		if (!access_ok(VERIFY_WRITE, (void *)unaligned_addr, len))
+			return -EACCES;
+
+		target_val = *idx_to_addr(regs, RT(inst));
+		set_data((void *)unaligned_addr, target_val, len);
+	}
+
+	if (!regular)
+		*idx_to_addr(regs, RA(inst)) = unaligned_addr + shift;
+
+	regs->ipc += 4;
+
+	return 0;
+fault:
+	return -EACCES;
+}
+
+int do_unaligned_access(unsigned long addr, struct pt_regs *regs)
+{
+	unsigned long inst;
+	int ret = -EFAULT;
+	mm_segment_t seg = get_fs();
+
+	inst = get_inst(regs->ipc);
+
+	DEBUG((unalign_access_debug > 0), 1,
+	      "Faulting addr: 0x%08lx, pc: 0x%08lx [inst: 0x%08lx ]\n", addr,
+	      regs->ipc, inst);
+
+	set_fs(USER_DS);
+
+	if (inst & NDS32_16BIT_INSTRUCTION)
+		ret = do_16((inst >> 16) & 0xffff, regs);
+	else
+		ret = do_32(inst, regs);
+	set_fs(seg);
+
+	return ret;
+}
+
+#ifdef CONFIG_PROC_FS
+
+static struct ctl_table alignment_tbl[3] = {
+	{
+	 .procname = "enable",
+	 .data = &unalign_access_mode,
+	 .maxlen = sizeof(unalign_access_mode),
+	 .mode = 0666,
+	 .proc_handler = &proc_dointvec
+	}
+	,
+	{
+	 .procname = "debug_info",
+	 .data = &unalign_access_debug,
+	 .maxlen = sizeof(unalign_access_debug),
+	 .mode = 0644,
+	 .proc_handler = &proc_dointvec
+	}
+	,
+	{}
+};
+
+static struct ctl_table nds32_sysctl_table[2] = {
+	{
+	 .procname = "unaligned_access",
+	 .mode = 0555,
+	 .child = alignment_tbl},
+	{}
+};
+
+static struct ctl_path nds32_path[2] = {
+	{.procname = "nds32"},
+	{}
+};
+
+/*
+ * Initialize nds32 alignment-correction interface
+ */
+static int __init nds32_sysctl_init(void)
+{
+	register_sysctl_paths(nds32_path, nds32_sysctl_table);
+	return 0;
+}
+
+__initcall(nds32_sysctl_init);
+#endif /* CONFIG_PROC_FS */