Merge tag 'xtensa-20230627' of https://github.com/jcmvbkbc/linux-xtensa

Pull xtensa updates from Max Filippov:

 - clean up platform_* interface of the xtensa architecture

 - enable HAVE_ASM_MODVERSIONS

 - drop ARCH_WANT_FRAME_POINTERS

 - clean up unaligned access exception handler

 - provide handler for load/store exceptions

 - various small fixes and cleanups

* tag 'xtensa-20230627' of https://github.com/jcmvbkbc/linux-xtensa:
  xtensa: dump userspace code around the exception PC
  xtensa: rearrange show_stack output
  xtensa: add load/store exception handler
  xtensa: rearrange unaligned exception handler
  xtensa: always install slow handler for unaligned access exception
  xtensa: move early_trap_init from kasan_early_init to init_arch
  xtensa: drop ARCH_WANT_FRAME_POINTERS
  xtensa: report trax and perf counters in cpuinfo
  xtensa: add asm-prototypes.h
  xtensa: only build __strncpy_user with CONFIG_ARCH_HAS_STRNCPY_FROM_USER
  xtensa: drop bcopy implementation
  xtensa: drop EXPORT_SYMBOL for common_exception_return
  xtensa: boot-redboot: clean up Makefile
  xtensa: clean up default platform functions
  xtensa: drop platform_halt and platform_power_off
  xtensa: drop platform_restart
  xtensa: drop platform_heartbeat
  xtensa: xt2000: drop empty platform_init

41 files changed, 467 insertions, 326 deletions

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 3c6e5471f025..c1bcfc2a8581 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -16,7 +16,6 @@ config XTENSA
 	select ARCH_USE_MEMTEST
 	select ARCH_USE_QUEUED_RWLOCKS
 	select ARCH_USE_QUEUED_SPINLOCKS
-	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select BUILDTIME_TABLE_SORT
 	select CLONE_BACKWARDS
@@ -35,6 +34,7 @@ config XTENSA
 	select HAVE_ARCH_KCSAN
 	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_ARCH_TRACEHOOK
+	select HAVE_ASM_MODVERSIONS
 	select HAVE_CONTEXT_TRACKING_USER
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DMA_CONTIGUOUS
@@ -203,6 +203,18 @@ config XTENSA_UNALIGNED_USER
 
 	  Say Y here to enable unaligned memory access in user space.
 
+config XTENSA_LOAD_STORE
+	bool "Load/store exception handler for memory only readable with l32"
+	help
+	  The Xtensa architecture only allows reading memory attached to its
+	  instruction bus with l32r and l32i instructions, all other
+	  instructions raise an exception with the LoadStoreErrorCause code.
+	  This makes it hard to use some configurations, e.g. store string
+	  literals in FLASH memory attached to the instruction bus.
+
+	  Say Y here to enable exception handler that allows transparent
+	  byte and 2-byte access to memory attached to instruction bus.
+
 config HAVE_SMP
 	bool "System Supports SMP (MX)"
 	depends on XTENSA_VARIANT_CUSTOM
diff --git a/arch/xtensa/Kconfig.debug b/arch/xtensa/Kconfig.debug
index 83cc8d12fa0e..e84172a7763c 100644
--- a/arch/xtensa/Kconfig.debug
+++ b/arch/xtensa/Kconfig.debug
@@ -38,3 +38,11 @@ config PRINT_STACK_DEPTH
 	help
 	  This option allows you to set the stack depth that the kernel
 	  prints in stack traces.
+
+config PRINT_USER_CODE_ON_UNHANDLED_EXCEPTION
+	bool "Dump user code around unhandled exception address"
+	help
+	  Enable this option to display user code around PC of the unhandled
+	  exception (starting at address aligned on 16 byte boundary).
+	  This may simplify finding faulting code in the absence of other
+	  debug facilities.
diff --git a/arch/xtensa/boot/boot-redboot/Makefile b/arch/xtensa/boot/boot-redboot/Makefile
index 1d1d46215b1c..c0eef3f6f32d 100644
--- a/arch/xtensa/boot/boot-redboot/Makefile
+++ b/arch/xtensa/boot/boot-redboot/Makefile
@@ -6,16 +6,12 @@
 
 OBJCOPY_ARGS := -O $(if $(CONFIG_CPU_BIG_ENDIAN),elf32-xtensa-be,elf32-xtensa-le)
 
-LD_ARGS	= -T $(srctree)/$(obj)/boot.ld
-
 boot-y	:= bootstrap.o
 targets	+= $(boot-y)
 
 OBJS	:= $(addprefix $(obj)/,$(boot-y))
 LIBS	:= arch/xtensa/boot/lib/lib.a arch/xtensa/lib/lib.a
 
-LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
-
 $(obj)/zImage.o: $(obj)/../vmlinux.bin.gz $(OBJS)
 	$(Q)$(OBJCOPY) $(OBJCOPY_ARGS) -R .comment \
 		--add-section image=$< \
@@ -23,7 +19,10 @@ $(obj)/zImage.o: $(obj)/../vmlinux.bin.gz $(OBJS)
 		$(OBJS) $@
 
 $(obj)/zImage.elf: $(obj)/zImage.o $(LIBS)
-	$(Q)$(LD) $(LD_ARGS) -o $@ $^ -L/xtensa-elf/lib $(LIBGCC)
+	$(Q)$(LD) $(KBUILD_LDFLAGS) \
+		-T $(srctree)/$(obj)/boot.ld \
+		--build-id=none \
+		-o $@ $^
 
 $(obj)/../zImage.redboot: $(obj)/zImage.elf
 	$(Q)$(OBJCOPY) -S -O binary $< $@
diff --git a/arch/xtensa/include/asm/asm-prototypes.h b/arch/xtensa/include/asm/asm-prototypes.h
new file mode 100644
index 000000000000..b0da61812b85
--- /dev/null
+++ b/arch/xtensa/include/asm/asm-prototypes.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_PROTOTYPES_H
+#define __ASM_PROTOTYPES_H
+
+#include <asm/cacheflush.h>
+#include <asm/checksum.h>
+#include <asm/ftrace.h>
+#include <asm/page.h>
+#include <asm/string.h>
+#include <asm/uaccess.h>
+
+#include <asm-generic/asm-prototypes.h>
+
+/*
+ * gcc internal math functions
+ */
+long long __ashrdi3(long long, int);
+long long __ashldi3(long long, int);
+long long __bswapdi2(long long);
+int __bswapsi2(int);
+long long __lshrdi3(long long, int);
+int __divsi3(int, int);
+int __modsi3(int, int);
+int __mulsi3(int, int);
+unsigned int __udivsi3(unsigned int, unsigned int);
+unsigned int __umodsi3(unsigned int, unsigned int);
+unsigned long long __umulsidi3(unsigned int, unsigned int);
+
+#endif /* __ASM_PROTOTYPES_H */
diff --git a/arch/xtensa/include/asm/asmmacro.h b/arch/xtensa/include/asm/asmmacro.h
index e3474ca411ff..01bf7d9dbb19 100644
--- a/arch/xtensa/include/asm/asmmacro.h
+++ b/arch/xtensa/include/asm/asmmacro.h
@@ -11,6 +11,7 @@
 #ifndef _XTENSA_ASMMACRO_H
 #define _XTENSA_ASMMACRO_H
 
+#include <asm-generic/export.h>
 #include <asm/core.h>
 
 /*
diff --git a/arch/xtensa/include/asm/core.h b/arch/xtensa/include/asm/core.h
index f856d2bcb9f3..0e1bb6f019d6 100644
--- a/arch/xtensa/include/asm/core.h
+++ b/arch/xtensa/include/asm/core.h
@@ -26,6 +26,14 @@
 #define XCHAL_SPANNING_WAY 0
 #endif
 
+#ifndef XCHAL_HAVE_TRAX
+#define XCHAL_HAVE_TRAX 0
+#endif
+
+#ifndef XCHAL_NUM_PERF_COUNTERS
+#define XCHAL_NUM_PERF_COUNTERS 0
+#endif
+
 #if XCHAL_HAVE_WINDOWED
 #if defined(CONFIG_USER_ABI_DEFAULT) || defined(CONFIG_USER_ABI_CALL0_PROBE)
 /* Whether windowed ABI is supported in userspace. */
diff --git a/arch/xtensa/include/asm/ftrace.h b/arch/xtensa/include/asm/ftrace.h
index 6c6d9a9f185f..0ea4f84cd558 100644
--- a/arch/xtensa/include/asm/ftrace.h
+++ b/arch/xtensa/include/asm/ftrace.h
@@ -13,17 +13,8 @@
 #include <asm/processor.h>
 
 #ifndef __ASSEMBLY__
-#define ftrace_return_address0 ({ unsigned long a0, a1; \
-		__asm__ __volatile__ ( \
-			"mov %0, a0\n" \
-			"mov %1, a1\n" \
-			: "=r"(a0), "=r"(a1)); \
-		MAKE_PC_FROM_RA(a0, a1); })
-
-#ifdef CONFIG_FRAME_POINTER
 extern unsigned long return_address(unsigned level);
 #define ftrace_return_address(n) return_address(n)
-#endif
 #endif /* __ASSEMBLY__ */
 
 #ifdef CONFIG_FUNCTION_TRACER
diff --git a/arch/xtensa/include/asm/platform.h b/arch/xtensa/include/asm/platform.h
index 354ca942de40..94f13fabf7cd 100644
--- a/arch/xtensa/include/asm/platform.h
+++ b/arch/xtensa/include/asm/platform.h
@@ -28,31 +28,11 @@ extern void platform_init(bp_tag_t*);
 extern void platform_setup (char **);
 
 /*
- * platform_restart is called to restart the system.
- */
-extern void platform_restart (void);
-
-/*
- * platform_halt is called to stop the system and halt.
- */
-extern void platform_halt (void);
-
-/*
- * platform_power_off is called to stop the system and power it off.
- */
-extern void platform_power_off (void);
-
-/*
  * platform_idle is called from the idle function.
  */
 extern void platform_idle (void);
 
 /*
- * platform_heartbeat is called every HZ
- */
-extern void platform_heartbeat (void);
-
-/*
  * platform_calibrate_ccount calibrates cpu clock freq (CONFIG_XTENSA_CALIBRATE)
  */
 extern void platform_calibrate_ccount (void);
diff --git a/arch/xtensa/include/asm/string.h b/arch/xtensa/include/asm/string.h
index 89b51a0c752f..ffce43513fa2 100644
--- a/arch/xtensa/include/asm/string.h
+++ b/arch/xtensa/include/asm/string.h
@@ -118,9 +118,6 @@ extern void *__memcpy(void *__to, __const__ void *__from, size_t __n);
 extern void *memmove(void *__dest, __const__ void *__src, size_t __n);
 extern void *__memmove(void *__dest, __const__ void *__src, size_t __n);
 
-/* Don't build bcopy at all ...  */
-#define __HAVE_ARCH_BCOPY
-
 #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
 
 /*
diff --git a/arch/xtensa/include/asm/traps.h b/arch/xtensa/include/asm/traps.h
index 6f74ccc0c7ea..212c3b9ff407 100644
--- a/arch/xtensa/include/asm/traps.h
+++ b/arch/xtensa/include/asm/traps.h
@@ -47,6 +47,7 @@ __init trap_set_handler(int cause, xtensa_exception_handler *handler);
 asmlinkage void fast_illegal_instruction_user(void);
 asmlinkage void fast_syscall_user(void);
 asmlinkage void fast_alloca(void);
+asmlinkage void fast_load_store(void);
 asmlinkage void fast_unaligned(void);
 asmlinkage void fast_second_level_miss(void);
 asmlinkage void fast_store_prohibited(void);
@@ -64,8 +65,14 @@ void do_unhandled(struct pt_regs *regs);
 static inline void __init early_trap_init(void)
 {
 	static struct exc_table init_exc_table __initdata = {
+#ifdef CONFIG_XTENSA_LOAD_STORE
+		.fast_kernel_handler[EXCCAUSE_LOAD_STORE_ERROR] =
+			fast_load_store,
+#endif
+#ifdef CONFIG_MMU
 		.fast_kernel_handler[EXCCAUSE_DTLB_MISS] =
 			fast_second_level_miss,
+#endif
 	};
 	xtensa_set_sr(&init_exc_table, excsave1);
 }
diff --git a/arch/xtensa/kernel/align.S b/arch/xtensa/kernel/align.S
index d062c732ef18..20d6b4961001 100644
--- a/arch/xtensa/kernel/align.S
+++ b/arch/xtensa/kernel/align.S
@@ -22,7 +22,17 @@
 #include <asm/asmmacro.h>
 #include <asm/processor.h>
 
-#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
+#if XCHAL_UNALIGNED_LOAD_EXCEPTION || defined CONFIG_XTENSA_LOAD_STORE
+#define LOAD_EXCEPTION_HANDLER
+#endif
+
+#if XCHAL_UNALIGNED_STORE_EXCEPTION || defined LOAD_EXCEPTION_HANDLER
+#define ANY_EXCEPTION_HANDLER
+#endif
+
+#if XCHAL_HAVE_WINDOWED
+#define UNALIGNED_USER_EXCEPTION
+#endif
 
 /*  First-level exception handler for unaligned exceptions.
  *
@@ -58,10 +68,6 @@
  *  BE  shift left / mask 0 0 X X
  */
 
-#if XCHAL_HAVE_WINDOWED
-#define UNALIGNED_USER_EXCEPTION
-#endif
-
 #if XCHAL_HAVE_BE
 
 #define HWORD_START	16
@@ -103,7 +109,7 @@
  *
  *	       23			    0
  *		-----------------------------
- *	res	          0000           0010
+ *	L8UI	xxxx xxxx 0000 ssss tttt 0010
  *	L16UI	xxxx xxxx 0001 ssss tttt 0010
  *	L32I	xxxx xxxx 0010 ssss tttt 0010
  *	XXX	          0011 ssss tttt 0010
@@ -128,9 +134,11 @@
 
 #define OP0_L32I_N	0x8		/* load immediate narrow */
 #define OP0_S32I_N	0x9		/* store immediate narrow */
+#define OP0_LSAI	0x2		/* load/store */
 #define OP1_SI_MASK	0x4		/* OP1 bit set for stores */
 #define OP1_SI_BIT	2		/* OP1 bit number for stores */
 
+#define OP1_L8UI	0x0
 #define OP1_L32I	0x2
 #define OP1_L16UI	0x1
 #define OP1_L16SI	0x9
@@ -155,60 +163,74 @@
  */
 
 	.literal_position
-ENTRY(fast_unaligned)
+#ifdef CONFIG_XTENSA_LOAD_STORE
+ENTRY(fast_load_store)
 
-	/* Note: We don't expect the address to be aligned on a word
-	 *       boundary. After all, the processor generated that exception
-	 *       and it would be a hardware fault.
-	 */
+	call0	.Lsave_and_load_instruction
 
-	/* Save some working register */
+	/* Analyze the instruction (load or store?). */
 
-	s32i	a4, a2, PT_AREG4
-	s32i	a5, a2, PT_AREG5
-	s32i	a6, a2, PT_AREG6
-	s32i	a7, a2, PT_AREG7
-	s32i	a8, a2, PT_AREG8
+	extui	a0, a4, INSN_OP0, 4	# get insn.op0 nibble
 
-	rsr	a0, depc
-	s32i	a0, a2, PT_AREG2
-	s32i	a3, a2, PT_AREG3
+#if XCHAL_HAVE_DENSITY
+	_beqi	a0, OP0_L32I_N, 1f	# L32I.N, jump
+#endif
+	bnei	a0, OP0_LSAI, .Linvalid_instruction
+	/* 'store indicator bit' set, jump */
+	bbsi.l	a4, OP1_SI_BIT + INSN_OP1, .Linvalid_instruction
 
-	rsr	a3, excsave1
-	movi	a4, fast_unaligned_fixup
-	s32i	a4, a3, EXC_TABLE_FIXUP
+1:
+	movi	a3, ~3
+	and	a3, a3, a8		# align memory address
 
-	/* Keep value of SAR in a0 */
+	__ssa8	a8
 
-	rsr	a0, sar
-	rsr	a8, excvaddr		# load unaligned memory address
+#ifdef CONFIG_MMU
+	/* l32e can't be used here even when it's available. */
+	/* TODO access_ok(a3) could be used here */
+	j	.Linvalid_instruction
+#endif
+	l32i	a5, a3, 0
+	l32i	a6, a3, 4
+	__src_b	a3, a5, a6		# a3 has the data word
 
-	/* Now, identify one of the following load/store instructions.
-	 *
-	 * The only possible danger of a double exception on the
-	 * following l32i instructions is kernel code in vmalloc
-	 * memory. The processor was just executing at the EPC_1
-	 * address, and indeed, already fetched the instruction.  That
-	 * guarantees a TLB mapping, which hasn't been replaced by
-	 * this unaligned exception handler that uses only static TLB
-	 * mappings. However, high-level interrupt handlers might
-	 * modify TLB entries, so for the generic case, we register a
-	 * TABLE_FIXUP handler here, too.
-	 */
+#if XCHAL_HAVE_DENSITY
+	addi	a7, a7, 2		# increment PC (assume 16-bit insn)
+	_beqi	a0, OP0_L32I_N, .Lload_w# l32i.n: jump
+	addi	a7, a7, 1
+#else
+	addi	a7, a7, 3
+#endif
 
-	/* a3...a6 saved on stack, a2 = SP */
+	extui	a5, a4, INSN_OP1, 4
+	_beqi	a5, OP1_L32I, .Lload_w
+	bnei	a5, OP1_L8UI, .Lload16
+	extui	a3, a3, 0, 8
+	j	.Lload_w
 
-	/* Extract the instruction that caused the unaligned access. */
+ENDPROC(fast_load_store)
+#endif
 
-	rsr	a7, epc1	# load exception address
-	movi	a3, ~3
-	and	a3, a3, a7	# mask lower bits
+/*
+ * Entry condition:
+ *
+ *   a0:	trashed, original value saved on stack (PT_AREG0)
+ *   a1:	a1
+ *   a2:	new stack pointer, original in DEPC
+ *   a3:	a3
+ *   depc:	a2, original value saved on stack (PT_DEPC)
+ *   excsave_1:	dispatch table
+ *
+ *   PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC
+ *	     <  VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception
+ */
 
-	l32i	a4, a3, 0	# load 2 words
-	l32i	a5, a3, 4
+#ifdef ANY_EXCEPTION_HANDLER
+ENTRY(fast_unaligned)
 
-	__ssa8	a7
-	__src_b	a4, a4, a5	# a4 has the instruction
+#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
+
+	call0	.Lsave_and_load_instruction
 
 	/* Analyze the instruction (load or store?). */
 
@@ -222,12 +244,17 @@ ENTRY(fast_unaligned)
 	/* 'store indicator bit' not set, jump */
 	_bbci.l	a4, OP1_SI_BIT + INSN_OP1, .Lload
 
+#endif
+#if XCHAL_UNALIGNED_STORE_EXCEPTION
+
 	/* Store: Jump to table entry to get the value in the source register.*/
 
 .Lstore:movi	a5, .Lstore_table	# table
 	extui	a6, a4, INSN_T, 4	# get source register
 	addx8	a5, a6, a5
 	jx	a5			# jump into table
+#endif
+#if XCHAL_UNALIGNED_LOAD_EXCEPTION
 
 	/* Load: Load memory address. */
 
@@ -249,7 +276,7 @@ ENTRY(fast_unaligned)
 	addi	a7, a7, 2		# increment PC (assume 16-bit insn)
 
 	extui	a5, a4, INSN_OP0, 4
-	_beqi	a5, OP0_L32I_N, 1f	# l32i.n: jump
+	_beqi	a5, OP0_L32I_N, .Lload_w# l32i.n: jump
 
 	addi	a7, a7, 1
 #else
@@ -257,21 +284,26 @@ ENTRY(fast_unaligned)
 #endif
 
 	extui	a5, a4, INSN_OP1, 4
-	_beqi	a5, OP1_L32I, 1f	# l32i: jump
-
+	_beqi	a5, OP1_L32I, .Lload_w	# l32i: jump
+#endif
+#ifdef LOAD_EXCEPTION_HANDLER
+.Lload16:
 	extui	a3, a3, 0, 16		# extract lower 16 bits
-	_beqi	a5, OP1_L16UI, 1f
+	_beqi	a5, OP1_L16UI, .Lload_w
 	addi	a5, a5, -OP1_L16SI
-	_bnez	a5, .Linvalid_instruction_load
+	_bnez	a5, .Linvalid_instruction
 
 	/* sign extend value */
-
+#if XCHAL_HAVE_SEXT
+	sext	a3, a3, 15
+#else
 	slli	a3, a3, 16
 	srai	a3, a3, 16
+#endif
 
 	/* Set target register. */
 
-1:
+.Lload_w:
 	extui	a4, a4, INSN_T, 4	# extract target register
 	movi	a5, .Lload_table
 	addx8	a4, a4, a5
@@ -295,30 +327,32 @@ ENTRY(fast_unaligned)
 	mov	a13, a3		;	_j .Lexit;	.align 8
 	mov	a14, a3		;	_j .Lexit;	.align 8
 	mov	a15, a3		;	_j .Lexit;	.align 8
-
+#endif
+#if XCHAL_UNALIGNED_STORE_EXCEPTION
 .Lstore_table:
-	l32i	a3, a2, PT_AREG0;	_j 1f;	.align 8
-	mov	a3, a1;			_j 1f;	.align 8	# fishy??
-	l32i	a3, a2, PT_AREG2;	_j 1f;	.align 8
-	l32i	a3, a2, PT_AREG3;	_j 1f;	.align 8
-	l32i	a3, a2, PT_AREG4;	_j 1f;	.align 8
-	l32i	a3, a2, PT_AREG5;	_j 1f;	.align 8
-	l32i	a3, a2, PT_AREG6;	_j 1f;	.align 8
-	l32i	a3, a2, PT_AREG7;	_j 1f;	.align 8
-	l32i	a3, a2, PT_AREG8;	_j 1f;	.align 8
-	mov	a3, a9		;	_j 1f;	.align 8
-	mov	a3, a10		;	_j 1f;	.align 8
-	mov	a3, a11		;	_j 1f;	.align 8
-	mov	a3, a12		;	_j 1f;	.align 8
-	mov	a3, a13		;	_j 1f;	.align 8
-	mov	a3, a14		;	_j 1f;	.align 8
-	mov	a3, a15		;	_j 1f;	.align 8
+	l32i	a3, a2, PT_AREG0;	_j .Lstore_w;	.align 8
+	mov	a3, a1;			_j .Lstore_w;	.align 8	# fishy??
+	l32i	a3, a2, PT_AREG2;	_j .Lstore_w;	.align 8
+	l32i	a3, a2, PT_AREG3;	_j .Lstore_w;	.align 8
+	l32i	a3, a2, PT_AREG4;	_j .Lstore_w;	.align 8
+	l32i	a3, a2, PT_AREG5;	_j .Lstore_w;	.align 8
+	l32i	a3, a2, PT_AREG6;	_j .Lstore_w;	.align 8
+	l32i	a3, a2, PT_AREG7;	_j .Lstore_w;	.align 8
+	l32i	a3, a2, PT_AREG8;	_j .Lstore_w;	.align 8
+	mov	a3, a9		;	_j .Lstore_w;	.align 8
+	mov	a3, a10		;	_j .Lstore_w;	.align 8
+	mov	a3, a11		;	_j .Lstore_w;	.align 8
+	mov	a3, a12		;	_j .Lstore_w;	.align 8
+	mov	a3, a13		;	_j .Lstore_w;	.align 8
+	mov	a3, a14		;	_j .Lstore_w;	.align 8
+	mov	a3, a15		;	_j .Lstore_w;	.align 8
+#endif
 
+#ifdef ANY_EXCEPTION_HANDLER
 	/* We cannot handle this exception. */
 
 	.extern _kernel_exception
-.Linvalid_instruction_load:
-.Linvalid_instruction_store:
+.Linvalid_instruction:
 
 	movi	a4, 0
 	rsr	a3, excsave1
@@ -326,6 +360,7 @@ ENTRY(fast_unaligned)
 
 	/* Restore a4...a8 and SAR, set SP, and jump to default exception. */
 
+	l32i	a0, a2, PT_SAR
 	l32i	a8, a2, PT_AREG8
 	l32i	a7, a2, PT_AREG7
 	l32i	a6, a2, PT_AREG6
@@ -342,9 +377,11 @@ ENTRY(fast_unaligned)
 
 2:	movi	a0, _user_exception
 	jx	a0
+#endif
+#if XCHAL_UNALIGNED_STORE_EXCEPTION
 
-1: 	# a7: instruction pointer, a4: instruction, a3: value
-
+	# a7: instruction pointer, a4: instruction, a3: value
+.Lstore_w:
 	movi	a6, 0			# mask: ffffffff:00000000
 
 #if XCHAL_HAVE_DENSITY
@@ -361,7 +398,7 @@ ENTRY(fast_unaligned)
 
 	extui	a5, a4, INSN_OP1, 4	# extract OP1
 	_beqi	a5, OP1_S32I, 1f	# jump if 32 bit store
-	_bnei	a5, OP1_S16I, .Linvalid_instruction_store
+	_bnei	a5, OP1_S16I, .Linvalid_instruction
 
 	movi	a5, -1
 	__extl	a3, a3			# get 16-bit value
@@ -406,7 +443,8 @@ ENTRY(fast_unaligned)
 #else
 	s32i	a6, a4, 4
 #endif
-
+#endif
+#ifdef ANY_EXCEPTION_HANDLER
 .Lexit:
 #if XCHAL_HAVE_LOOPS
 	rsr	a4, lend		# check if we reached LEND
@@ -434,6 +472,7 @@ ENTRY(fast_unaligned)
 
 	/* Restore working register */
 
+	l32i	a0, a2, PT_SAR
 	l32i	a8, a2, PT_AREG8
 	l32i	a7, a2, PT_AREG7
 	l32i	a6, a2, PT_AREG6
@@ -448,6 +487,59 @@ ENTRY(fast_unaligned)
 	l32i	a2, a2, PT_AREG2
 	rfe
 
+	.align	4
+.Lsave_and_load_instruction:
+
+	/* Save some working register */
+
+	s32i	a3, a2, PT_AREG3
+	s32i	a4, a2, PT_AREG4
+	s32i	a5, a2, PT_AREG5
+	s32i	a6, a2, PT_AREG6
+	s32i	a7, a2, PT_AREG7
+	s32i	a8, a2, PT_AREG8
+
+	rsr	a4, depc
+	s32i	a4, a2, PT_AREG2
+
+	rsr	a5, sar
+	s32i	a5, a2, PT_SAR
+
+	rsr	a3, excsave1
+	movi	a4, fast_unaligned_fixup
+	s32i	a4, a3, EXC_TABLE_FIXUP
+
+	rsr	a8, excvaddr		# load unaligned memory address
+
+	/* Now, identify one of the following load/store instructions.
+	 *
+	 * The only possible danger of a double exception on the
+	 * following l32i instructions is kernel code in vmalloc
+	 * memory. The processor was just executing at the EPC_1
+	 * address, and indeed, already fetched the instruction.  That
+	 * guarantees a TLB mapping, which hasn't been replaced by
+	 * this unaligned exception handler that uses only static TLB
+	 * mappings. However, high-level interrupt handlers might
+	 * modify TLB entries, so for the generic case, we register a
+	 * TABLE_FIXUP handler here, too.
+	 */
+
+	/* a3...a6 saved on stack, a2 = SP */
+
+	/* Extract the instruction that caused the unaligned access. */
+
+	rsr	a7, epc1	# load exception address
+	movi	a3, ~3
+	and	a3, a3, a7	# mask lower bits
+
+	l32i	a4, a3, 0	# load 2 words
+	l32i	a5, a3, 4
+
+	__ssa8	a7
+	__src_b	a4, a4, a5	# a4 has the instruction
+
+	ret
+#endif
 ENDPROC(fast_unaligned)
 
 ENTRY(fast_unaligned_fixup)
@@ -459,10 +551,11 @@ ENTRY(fast_unaligned_fixup)
 	l32i	a7, a2, PT_AREG7
 	l32i	a6, a2, PT_AREG6
 	l32i	a5, a2, PT_AREG5
-	l32i	a4, a2, PT_AREG4
+	l32i	a4, a2, PT_SAR
 	l32i	a0, a2, PT_AREG2
-	xsr	a0, depc			# restore depc and a0
-	wsr	a0, sar
+	wsr	a4, sar
+	wsr	a0, depc			# restore depc and a0
+	l32i	a4, a2, PT_AREG4
 
 	rsr	a0, exccause
 	s32i	a0, a2, PT_DEPC			# mark as a regular exception
@@ -483,5 +576,4 @@ ENTRY(fast_unaligned_fixup)
 	jx	a0
 
 ENDPROC(fast_unaligned_fixup)
-
-#endif /* XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION */
+#endif
diff --git a/arch/xtensa/kernel/mcount.S b/arch/xtensa/kernel/mcount.S
index 51daaf4e0b82..309b3298258f 100644
--- a/arch/xtensa/kernel/mcount.S
+++ b/arch/xtensa/kernel/mcount.S
@@ -78,6 +78,7 @@ ENTRY(_mcount)
 #error Unsupported Xtensa ABI
 #endif
 ENDPROC(_mcount)
+EXPORT_SYMBOL(_mcount)
 
 ENTRY(ftrace_stub)
 	abi_entry_default
diff --git a/arch/xtensa/kernel/platform.c b/arch/xtensa/kernel/platform.c
index ac1e0e566995..926b8bf0f14c 100644
--- a/arch/xtensa/kernel/platform.c
+++ b/arch/xtensa/kernel/platform.c
@@ -17,27 +17,28 @@
 #include <asm/platform.h>
 #include <asm/timex.h>
 
-#define _F(r,f,a,b)							\
-	r __platform_##f a b;                                   	\
-	r platform_##f a __attribute__((weak, alias("__platform_"#f)))
-
 /*
  * Default functions that are used if no platform specific function is defined.
- * (Please, refer to include/asm-xtensa/platform.h for more information)
+ * (Please, refer to arch/xtensa/include/asm/platform.h for more information)
  */
 
-_F(void, init, (bp_tag_t *first), { });
-_F(void, setup, (char** cmd), { });
-_F(void, restart, (void), { while(1); });
-_F(void, halt, (void), { while(1); });
-_F(void, power_off, (void), { while(1); });
-_F(void, idle, (void), { __asm__ __volatile__ ("waiti 0" ::: "memory"); });
-_F(void, heartbeat, (void), { });
+void __weak __init platform_init(bp_tag_t *first)
+{
+}
+
+void __weak __init platform_setup(char **cmd)
+{
+}
+
+void __weak platform_idle(void)
+{
+	__asm__ __volatile__ ("waiti 0" ::: "memory");
+}
 
 #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
-_F(void, calibrate_ccount, (void),
+void __weak platform_calibrate_ccount(void)
 {
 	pr_err("ERROR: Cannot calibrate cpu frequency! Assuming 10MHz.\n");
 	ccount_freq = 10 * 1000000UL;
-});
+}
 #endif
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index 9191738f9941..aba3ff4e60d8 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -22,6 +22,7 @@
 #include <linux/screen_info.h>
 #include <linux/kernel.h>
 #include <linux/percpu.h>
+#include <linux/reboot.h>
 #include <linux/cpu.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
@@ -46,6 +47,7 @@
 #include <asm/smp.h>
 #include <asm/sysmem.h>
 #include <asm/timex.h>
+#include <asm/traps.h>
 
 #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
 struct screen_info screen_info = {
@@ -241,6 +243,12 @@ void __init early_init_devtree(void *params)
 
 void __init init_arch(bp_tag_t *bp_start)
 {
+	/* Initialize basic exception handling if configuration may need it */
+
+	if (IS_ENABLED(CONFIG_KASAN) ||
+	    IS_ENABLED(CONFIG_XTENSA_LOAD_STORE))
+		early_trap_init();
+
 	/* Initialize MMU. */
 
 	init_mmu();
@@ -522,19 +530,30 @@ void cpu_reset(void)
 
 void machine_restart(char * cmd)
 {
-	platform_restart();
+	local_irq_disable();
+	smp_send_stop();
+	do_kernel_restart(cmd);
+	pr_err("Reboot failed -- System halted\n");
+	while (1)
+		cpu_relax();
 }
 
 void machine_halt(void)
 {
-	platform_halt();
-	while (1);
+	local_irq_disable();
+	smp_send_stop();
+	do_kernel_power_off();
+	while (1)
+		cpu_relax();
 }
 
 void machine_power_off(void)
 {
-	platform_power_off();
-	while (1);
+	local_irq_disable();
+	smp_send_stop();
+	do_kernel_power_off();
+	while (1)
+		cpu_relax();
 }
 #ifdef CONFIG_PROC_FS
 
@@ -574,6 +593,12 @@ c_show(struct seq_file *f, void *slot)
 # if XCHAL_HAVE_OCD
 		     "ocd "
 # endif
+#if XCHAL_HAVE_TRAX
+		     "trax "
+#endif
+#if XCHAL_NUM_PERF_COUNTERS
+		     "perf "
+#endif
 #endif
 #if XCHAL_HAVE_DENSITY
 	    	     "density "
@@ -623,11 +648,13 @@ c_show(struct seq_file *f, void *slot)
 	seq_printf(f,"physical aregs\t: %d\n"
 		     "misc regs\t: %d\n"
 		     "ibreak\t\t: %d\n"
-		     "dbreak\t\t: %d\n",
+		     "dbreak\t\t: %d\n"
+		     "perf counters\t: %d\n",
 		     XCHAL_NUM_AREGS,
 		     XCHAL_NUM_MISC_REGS,
 		     XCHAL_NUM_IBREAK,
-		     XCHAL_NUM_DBREAK);
+		     XCHAL_NUM_DBREAK,
+		     XCHAL_NUM_PERF_COUNTERS);
 
 
 	/* Interrupt. */
diff --git a/arch/xtensa/kernel/stacktrace.c b/arch/xtensa/kernel/stacktrace.c
index 7f7755cd28f0..f643ea5e36da 100644
--- a/arch/xtensa/kernel/stacktrace.c
+++ b/arch/xtensa/kernel/stacktrace.c
@@ -237,8 +237,6 @@ EXPORT_SYMBOL_GPL(save_stack_trace);
 
 #endif
 
-#ifdef CONFIG_FRAME_POINTER
-
 struct return_addr_data {
 	unsigned long addr;
 	unsigned skip;
@@ -271,5 +269,3 @@ unsigned long return_address(unsigned level)
 	return r.addr;
 }
 EXPORT_SYMBOL(return_address);
-
-#endif
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c
index 16b8a6273772..1c3dfea843ec 100644
--- a/arch/xtensa/kernel/time.c
+++ b/arch/xtensa/kernel/time.c
@@ -121,10 +121,6 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id)
 
 	set_linux_timer(get_linux_timer());
 	evt->event_handler(evt);
-
-	/* Allow platform to do something useful (Wdog). */
-	platform_heartbeat();
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index f0a7d1c2641e..17eb180eff7c 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -54,9 +54,10 @@ static void do_interrupt(struct pt_regs *regs);
 #if XTENSA_FAKE_NMI
 static void do_nmi(struct pt_regs *regs);
 #endif
-#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
-static void do_unaligned_user(struct pt_regs *regs);
+#ifdef CONFIG_XTENSA_LOAD_STORE
+static void do_load_store(struct pt_regs *regs);
 #endif
+static void do_unaligned_user(struct pt_regs *regs);
 static void do_multihit(struct pt_regs *regs);
 #if XTENSA_HAVE_COPROCESSORS
 static void do_coprocessor(struct pt_regs *regs);
@@ -91,7 +92,10 @@ static dispatch_init_table_t __initdata dispatch_init_table[] = {
 { EXCCAUSE_SYSTEM_CALL,		USER,	   fast_syscall_user },
 { EXCCAUSE_SYSTEM_CALL,		0,	   system_call },
 /* EXCCAUSE_INSTRUCTION_FETCH unhandled */
-/* EXCCAUSE_LOAD_STORE_ERROR unhandled*/
+#ifdef CONFIG_XTENSA_LOAD_STORE
+{ EXCCAUSE_LOAD_STORE_ERROR,	USER|KRNL, fast_load_store },
+{ EXCCAUSE_LOAD_STORE_ERROR,	0,	   do_load_store },
+#endif
 { EXCCAUSE_LEVEL1_INTERRUPT,	0,	   do_interrupt },
 #ifdef SUPPORT_WINDOWED
 { EXCCAUSE_ALLOCA,		USER|KRNL, fast_alloca },
@@ -102,9 +106,9 @@ static dispatch_init_table_t __initdata dispatch_init_table[] = {
 #ifdef CONFIG_XTENSA_UNALIGNED_USER
 { EXCCAUSE_UNALIGNED,		USER,	   fast_unaligned },
 #endif
-{ EXCCAUSE_UNALIGNED,		0,	   do_unaligned_user },
 { EXCCAUSE_UNALIGNED,		KRNL,	   fast_unaligned },
 #endif
+{ EXCCAUSE_UNALIGNED,		0,	   do_unaligned_user },
 #ifdef CONFIG_MMU
 { EXCCAUSE_ITLB_MISS,			0,	   do_page_fault },
 { EXCCAUSE_ITLB_MISS,			USER|KRNL, fast_second_level_miss},
@@ -171,6 +175,23 @@ __die_if_kernel(const char *str, struct pt_regs *regs, long err)
 		die(str, regs, err);
 }
 
+#ifdef CONFIG_PRINT_USER_CODE_ON_UNHANDLED_EXCEPTION
+static inline void dump_user_code(struct pt_regs *regs)
+{
+	char buf[32];
+
+	if (copy_from_user(buf, (void __user *)(regs->pc & -16), sizeof(buf)) == 0) {
+		print_hex_dump(KERN_INFO, " ", DUMP_PREFIX_NONE,
+			       32, 1, buf, sizeof(buf), false);
+
+	}
+}
+#else
+static inline void dump_user_code(struct pt_regs *regs)
+{
+}
+#endif
+
 /*
  * Unhandled Exceptions. Kill user task or panic if in kernel space.
  */
@@ -186,6 +207,7 @@ void do_unhandled(struct pt_regs *regs)
 			    "\tEXCCAUSE is %ld\n",
 			    current->comm, task_pid_nr(current), regs->pc,
 			    regs->exccause);
+	dump_user_code(regs);
 	force_sig(SIGILL);
 }
 
@@ -349,6 +371,19 @@ static void do_div0(struct pt_regs *regs)
 	force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->pc);
 }
 
+#ifdef CONFIG_XTENSA_LOAD_STORE
+static void do_load_store(struct pt_regs *regs)
+{
+	__die_if_kernel("Unhandled load/store exception in kernel",
+			regs, SIGKILL);
+
+	pr_info_ratelimited("Load/store error to %08lx in '%s' (pid = %d, pc = %#010lx)\n",
+			    regs->excvaddr, current->comm,
+			    task_pid_nr(current), regs->pc);
+	force_sig_fault(SIGBUS, BUS_ADRERR, (void *)regs->excvaddr);
+}
+#endif
+
 /*
  * Handle unaligned memory accesses from user space. Kill task.
  *
@@ -356,7 +391,6 @@ static void do_div0(struct pt_regs *regs)
  * accesses causes from user space.
  */
 
-#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
 static void do_unaligned_user(struct pt_regs *regs)
 {
 	__die_if_kernel("Unhandled unaligned exception in kernel",
@@ -368,7 +402,6 @@ static void do_unaligned_user(struct pt_regs *regs)
 			    task_pid_nr(current), regs->pc);
 	force_sig_fault(SIGBUS, BUS_ADRALN, (void *) regs->excvaddr);
 }
-#endif
 
 #if XTENSA_HAVE_COPROCESSORS
 static void do_coprocessor(struct pt_regs *regs)
@@ -534,31 +567,58 @@ static void show_trace(struct task_struct *task, unsigned long *sp,
 }
 
 #define STACK_DUMP_ENTRY_SIZE 4
-#define STACK_DUMP_LINE_SIZE 32
+#define STACK_DUMP_LINE_SIZE 16
 static size_t kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
 
-void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
+struct stack_fragment
 {
-	size_t len, off = 0;
-
-	if (!sp)
-		sp = stack_pointer(task);
+	size_t len;
+	size_t off;
+	u8 *sp;
+	const char *loglvl;
+};
 
-	len = min((-(size_t)sp) & (THREAD_SIZE - STACK_DUMP_ENTRY_SIZE),
-		  kstack_depth_to_print * STACK_DUMP_ENTRY_SIZE);
+static int show_stack_fragment_cb(struct stackframe *frame, void *data)
+{
+	struct stack_fragment *sf = data;
 
-	printk("%sStack:\n", loglvl);
-	while (off < len) {
+	while (sf->off < sf->len) {
 		u8 line[STACK_DUMP_LINE_SIZE];
-		size_t line_len = len - off > STACK_DUMP_LINE_SIZE ?
-			STACK_DUMP_LINE_SIZE : len - off;
+		size_t line_len = sf->len - sf->off > STACK_DUMP_LINE_SIZE ?
+			STACK_DUMP_LINE_SIZE : sf->len - sf->off;
+		bool arrow = sf->off == 0;
 
-		__memcpy(line, (u8 *)sp + off, line_len);
-		print_hex_dump(loglvl, " ", DUMP_PREFIX_NONE,
+		if (frame && frame->sp == (unsigned long)(sf->sp + sf->off))
+			arrow = true;
+
+		__memcpy(line, sf->sp + sf->off, line_len);
+		print_hex_dump(sf->loglvl, arrow ? "> " : "  ", DUMP_PREFIX_NONE,
 			       STACK_DUMP_LINE_SIZE, STACK_DUMP_ENTRY_SIZE,
 			       line, line_len, false);
-		off += STACK_DUMP_LINE_SIZE;
+		sf->off += STACK_DUMP_LINE_SIZE;
+		if (arrow)
+			return 0;
 	}
+	return 1;
+}
+
+void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
+{
+	struct stack_fragment sf;
+
+	if (!sp)
+		sp = stack_pointer(task);
+
+	sf.len = min((-(size_t)sp) & (THREAD_SIZE - STACK_DUMP_ENTRY_SIZE),
+		     kstack_depth_to_print * STACK_DUMP_ENTRY_SIZE);
+	sf.off = 0;
+	sf.sp = (u8 *)sp;
+	sf.loglvl = loglvl;
+
+	printk("%sStack:\n", loglvl);
+	walk_stackframe(sp, show_stack_fragment_cb, &sf);
+	while (sf.off < sf.len)
+		show_stack_fragment_cb(NULL, &sf);
 	show_trace(task, sp, loglvl);
 }
 
diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c
index 17a7ef86fd0d..62d81e76e18e 100644
--- a/arch/xtensa/kernel/xtensa_ksyms.c
+++ b/arch/xtensa/kernel/xtensa_ksyms.c
@@ -13,71 +13,10 @@
  */
 
 #include <linux/module.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/interrupt.h>
-#include <asm/irq.h>
-#include <linux/in6.h>
-
-#include <linux/uaccess.h>
-#include <asm/cacheflush.h>
-#include <asm/checksum.h>
-#include <asm/dma.h>
-#include <asm/io.h>
-#include <asm/page.h>
-#include <asm/ftrace.h>
-#ifdef CONFIG_BLK_DEV_FD
-#include <asm/floppy.h>
-#endif
-#ifdef CONFIG_NET
-#include <net/checksum.h>
-#endif /* CONFIG_NET */
-
-
-/*
- * String functions
- */
-EXPORT_SYMBOL(memset);
-EXPORT_SYMBOL(memcpy);
-EXPORT_SYMBOL(memmove);
-EXPORT_SYMBOL(__memset);
-EXPORT_SYMBOL(__memcpy);
-EXPORT_SYMBOL(__memmove);
-#ifdef CONFIG_ARCH_HAS_STRNCPY_FROM_USER
-EXPORT_SYMBOL(__strncpy_user);
-#endif
-EXPORT_SYMBOL(clear_page);
-EXPORT_SYMBOL(copy_page);
+#include <asm/pgtable.h>
 
 EXPORT_SYMBOL(empty_zero_page);
 
-/*
- * gcc internal math functions
- */
-extern long long __ashrdi3(long long, int);
-extern long long __ashldi3(long long, int);
-extern long long __bswapdi2(long long);
-extern int __bswapsi2(int);
-extern long long __lshrdi3(long long, int);
-extern int __divsi3(int, int);
-extern int __modsi3(int, int);
-extern int __mulsi3(int, int);
-extern unsigned int __udivsi3(unsigned int, unsigned int);
-extern unsigned int __umodsi3(unsigned int, unsigned int);
-extern unsigned long long __umulsidi3(unsigned int, unsigned int);
-
-EXPORT_SYMBOL(__ashldi3);
-EXPORT_SYMBOL(__ashrdi3);
-EXPORT_SYMBOL(__bswapdi2);
-EXPORT_SYMBOL(__bswapsi2);
-EXPORT_SYMBOL(__lshrdi3);
-EXPORT_SYMBOL(__divsi3);
-EXPORT_SYMBOL(__modsi3);
-EXPORT_SYMBOL(__mulsi3);
-EXPORT_SYMBOL(__udivsi3);
-EXPORT_SYMBOL(__umodsi3);
-EXPORT_SYMBOL(__umulsidi3);
-
 unsigned int __sync_fetch_and_and_4(volatile void *p, unsigned int v)
 {
 	BUG();
@@ -89,35 +28,3 @@ unsigned int __sync_fetch_and_or_4(volatile void *p, unsigned int v)
 	BUG();
 }
 EXPORT_SYMBOL(__sync_fetch_and_or_4);
-
-/*
- * Networking support
- */
-EXPORT_SYMBOL(csum_partial);
-EXPORT_SYMBOL(csum_partial_copy_generic);
-
-/*
- * Architecture-specific symbols
- */
-EXPORT_SYMBOL(__xtensa_copy_user);
-EXPORT_SYMBOL(__invalidate_icache_range);
-
-/*
- * Kernel hacking ...
- */
-
-#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
-// FIXME EXPORT_SYMBOL(screen_info);
-#endif
-
-extern long common_exception_return;
-EXPORT_SYMBOL(common_exception_return);
-
-#ifdef CONFIG_FUNCTION_TRACER
-EXPORT_SYMBOL(_mcount);
-#endif
-
-EXPORT_SYMBOL(__invalidate_dcache_range);
-#if XCHAL_DCACHE_IS_WRITEBACK
-EXPORT_SYMBOL(__flush_dcache_range);
-#endif
diff --git a/arch/xtensa/lib/Makefile b/arch/xtensa/lib/Makefile
index c9c2614188f7..6e5b2232668c 100644
--- a/arch/xtensa/lib/Makefile
+++ b/arch/xtensa/lib/Makefile
@@ -6,7 +6,8 @@
 lib-y	+= memcopy.o memset.o checksum.o \
 	   ashldi3.o ashrdi3.o bswapdi2.o bswapsi2.o lshrdi3.o \
 	   divsi3.o udivsi3.o modsi3.o umodsi3.o mulsi3.o umulsidi3.o \
-	   usercopy.o strncpy_user.o strnlen_user.o
+	   usercopy.o strnlen_user.o
+lib-$(CONFIG_ARCH_HAS_STRNCPY_FROM_USER) += strncpy_user.o
 lib-$(CONFIG_PCI) += pci-auto.o
 lib-$(CONFIG_KCSAN) += kcsan-stubs.o
 KCSAN_SANITIZE_kcsan-stubs.o := n
diff --git a/arch/xtensa/lib/ashldi3.S b/arch/xtensa/lib/ashldi3.S
index 67fb0da9e432..cd6b731215d3 100644
--- a/arch/xtensa/lib/ashldi3.S
+++ b/arch/xtensa/lib/ashldi3.S
@@ -26,3 +26,4 @@ ENTRY(__ashldi3)
 	abi_ret_default
 
 ENDPROC(__ashldi3)
+EXPORT_SYMBOL(__ashldi3)
diff --git a/arch/xtensa/lib/ashrdi3.S b/arch/xtensa/lib/ashrdi3.S
index cbf052c512cc..07bc6e758020 100644
--- a/arch/xtensa/lib/ashrdi3.S
+++ b/arch/xtensa/lib/ashrdi3.S
@@ -26,3 +26,4 @@ ENTRY(__ashrdi3)
 	abi_ret_default
 
 ENDPROC(__ashrdi3)
+EXPORT_SYMBOL(__ashrdi3)
diff --git a/arch/xtensa/lib/bswapdi2.S b/arch/xtensa/lib/bswapdi2.S
index d8e52e05eba6..5d94a9352887 100644
--- a/arch/xtensa/lib/bswapdi2.S
+++ b/arch/xtensa/lib/bswapdi2.S
@@ -19,3 +19,4 @@ ENTRY(__bswapdi2)
 	abi_ret_default
 
 ENDPROC(__bswapdi2)
+EXPORT_SYMBOL(__bswapdi2)
diff --git a/arch/xtensa/lib/bswapsi2.S b/arch/xtensa/lib/bswapsi2.S
index 9c1de1344f79..fbfb8613d410 100644
--- a/arch/xtensa/lib/bswapsi2.S
+++ b/arch/xtensa/lib/bswapsi2.S
@@ -14,3 +14,4 @@ ENTRY(__bswapsi2)
 	abi_ret_default
 
 ENDPROC(__bswapsi2)
+EXPORT_SYMBOL(__bswapsi2)
diff --git a/arch/xtensa/lib/checksum.S b/arch/xtensa/lib/checksum.S
index cf1bed1a5bd6..ffee6f94c8f8 100644
--- a/arch/xtensa/lib/checksum.S
+++ b/arch/xtensa/lib/checksum.S
@@ -169,6 +169,7 @@ ENTRY(csum_partial)
 	j	5b		/* branch to handle the remaining byte */
 
 ENDPROC(csum_partial)
+EXPORT_SYMBOL(csum_partial)
 
 /*
  * Copy from ds while checksumming, otherwise like csum_partial
@@ -346,6 +347,7 @@ EX(10f)	s8i	a8, a3, 1
 	j	4b		/* process the possible trailing odd byte */
 
 ENDPROC(csum_partial_copy_generic)
+EXPORT_SYMBOL(csum_partial_copy_generic)
 
 
 # Exception handler:
diff --git a/arch/xtensa/lib/divsi3.S b/arch/xtensa/lib/divsi3.S
index b044b4744a8b..edb3c4ad971b 100644
--- a/arch/xtensa/lib/divsi3.S
+++ b/arch/xtensa/lib/divsi3.S
@@ -72,3 +72,4 @@ ENTRY(__divsi3)
 	abi_ret_default
 
 ENDPROC(__divsi3)
+EXPORT_SYMBOL(__divsi3)
diff --git a/arch/xtensa/lib/lshrdi3.S b/arch/xtensa/lib/lshrdi3.S
index 129ef8d1725b..e432e1a40702 100644
--- a/arch/xtensa/lib/lshrdi3.S
+++ b/arch/xtensa/lib/lshrdi3.S
@@ -26,3 +26,4 @@ ENTRY(__lshrdi3)
 	abi_ret_default
 
 ENDPROC(__lshrdi3)
+EXPORT_SYMBOL(__lshrdi3)
diff --git a/arch/xtensa/lib/memcopy.S b/arch/xtensa/lib/memcopy.S
index b20d206bcb71..f60760396cee 100644
--- a/arch/xtensa/lib/memcopy.S
+++ b/arch/xtensa/lib/memcopy.S
@@ -273,21 +273,8 @@ WEAK(memcpy)
 	abi_ret_default
 
 ENDPROC(__memcpy)
-
-/*
- * void bcopy(const void *src, void *dest, size_t n);
- */
-
-ENTRY(bcopy)
-
-	abi_entry_default
-	# a2=src, a3=dst, a4=len
-	mov	a5, a3
-	mov	a3, a2
-	mov	a2, a5
-	j	.Lmovecommon	# go to common code for memmove+bcopy
-
-ENDPROC(bcopy)
+EXPORT_SYMBOL(__memcpy)
+EXPORT_SYMBOL(memcpy)
 
 /*
  * void *memmove(void *dst, const void *src, size_t len);
@@ -551,3 +538,5 @@ WEAK(memmove)
 	abi_ret_default
 
 ENDPROC(__memmove)
+EXPORT_SYMBOL(__memmove)
+EXPORT_SYMBOL(memmove)
diff --git a/arch/xtensa/lib/memset.S b/arch/xtensa/lib/memset.S
index 59b1524fd601..262c3f39f945 100644
--- a/arch/xtensa/lib/memset.S
+++ b/arch/xtensa/lib/memset.S
@@ -142,6 +142,8 @@ EX(10f) s8i	a3, a5, 0
 	abi_ret_default
 
 ENDPROC(__memset)
+EXPORT_SYMBOL(__memset)
+EXPORT_SYMBOL(memset)
 
 	.section .fixup, "ax"
 	.align	4
diff --git a/arch/xtensa/lib/modsi3.S b/arch/xtensa/lib/modsi3.S
index d00e77181e20..c5f4295c6868 100644
--- a/arch/xtensa/lib/modsi3.S
+++ b/arch/xtensa/lib/modsi3.S
@@ -60,6 +60,7 @@ ENTRY(__modsi3)
 	abi_ret_default
 
 ENDPROC(__modsi3)
+EXPORT_SYMBOL(__modsi3)
 
 #if !XCHAL_HAVE_NSA
 	.section .rodata
diff --git a/arch/xtensa/lib/mulsi3.S b/arch/xtensa/lib/mulsi3.S
index 91a9d7c62f96..c6b4fd46bfa9 100644
--- a/arch/xtensa/lib/mulsi3.S
+++ b/arch/xtensa/lib/mulsi3.S
@@ -131,3 +131,4 @@ ENTRY(__mulsi3)
 	abi_ret_default
 
 ENDPROC(__mulsi3)
+EXPORT_SYMBOL(__mulsi3)
diff --git a/arch/xtensa/lib/strncpy_user.S b/arch/xtensa/lib/strncpy_user.S
index 0731912227d3..9841d1694cdf 100644
--- a/arch/xtensa/lib/strncpy_user.S
+++ b/arch/xtensa/lib/strncpy_user.S
@@ -201,6 +201,7 @@ EX(10f)	s8i	a9, a11, 0
 	abi_ret_default
 
 ENDPROC(__strncpy_user)
+EXPORT_SYMBOL(__strncpy_user)
 
 	.section .fixup, "ax"
 	.align	4
diff --git a/arch/xtensa/lib/strnlen_user.S b/arch/xtensa/lib/strnlen_user.S
index 3d391dca3efb..cdcf57474164 100644
--- a/arch/xtensa/lib/strnlen_user.S
+++ b/arch/xtensa/lib/strnlen_user.S
@@ -133,6 +133,7 @@ EX(10f)	l32i	a9, a4, 0	# get word with first two bytes of string
 	abi_ret_default
 
 ENDPROC(__strnlen_user)
+EXPORT_SYMBOL(__strnlen_user)
 
 	.section .fixup, "ax"
 	.align	4
diff --git a/arch/xtensa/lib/udivsi3.S b/arch/xtensa/lib/udivsi3.S
index d2477e0786cf..59ea2dfc3f72 100644
--- a/arch/xtensa/lib/udivsi3.S
+++ b/arch/xtensa/lib/udivsi3.S
@@ -66,3 +66,4 @@ ENTRY(__udivsi3)
 	abi_ret_default
 
 ENDPROC(__udivsi3)
+EXPORT_SYMBOL(__udivsi3)
diff --git a/arch/xtensa/lib/umodsi3.S b/arch/xtensa/lib/umodsi3.S
index 5f031bfa0354..d39a7e56a971 100644
--- a/arch/xtensa/lib/umodsi3.S
+++ b/arch/xtensa/lib/umodsi3.S
@@ -55,3 +55,4 @@ ENTRY(__umodsi3)
 	abi_ret_default
 
 ENDPROC(__umodsi3)
+EXPORT_SYMBOL(__umodsi3)
diff --git a/arch/xtensa/lib/umulsidi3.S b/arch/xtensa/lib/umulsidi3.S
index 136081647942..8c7a94a0c5d0 100644
--- a/arch/xtensa/lib/umulsidi3.S
+++ b/arch/xtensa/lib/umulsidi3.S
@@ -228,3 +228,4 @@ ENTRY(__umulsidi3)
 #endif /* XCHAL_NO_MUL */
 
 ENDPROC(__umulsidi3)
+EXPORT_SYMBOL(__umulsidi3)
diff --git a/arch/xtensa/lib/usercopy.S b/arch/xtensa/lib/usercopy.S
index 16128c094c62..2c665c0b408e 100644
--- a/arch/xtensa/lib/usercopy.S
+++ b/arch/xtensa/lib/usercopy.S
@@ -283,6 +283,7 @@ EX(10f)	s8i	a6, a5,  0
 	abi_ret(STACK_SIZE)
 
 ENDPROC(__xtensa_copy_user)
+EXPORT_SYMBOL(__xtensa_copy_user)
 
 	.section .fixup, "ax"
 	.align	4
diff --git a/arch/xtensa/mm/kasan_init.c b/arch/xtensa/mm/kasan_init.c
index 1fef24db2ff6..f00d122aa806 100644
--- a/arch/xtensa/mm/kasan_init.c
+++ b/arch/xtensa/mm/kasan_init.c
@@ -14,7 +14,6 @@
 #include <linux/kernel.h>
 #include <asm/initialize_mmu.h>
 #include <asm/tlbflush.h>
-#include <asm/traps.h>
 
 void __init kasan_early_init(void)
 {
@@ -31,7 +30,6 @@ void __init kasan_early_init(void)
 		BUG_ON(!pmd_none(*pmd));
 		set_pmd(pmd, __pmd((unsigned long)kasan_early_shadow_pte));
 	}
-	early_trap_init();
 }
 
 static void __init populate(void *start, void *end)
diff --git a/arch/xtensa/mm/misc.S b/arch/xtensa/mm/misc.S
index 0527bf6e3211..ec36f73c4765 100644
--- a/arch/xtensa/mm/misc.S
+++ b/arch/xtensa/mm/misc.S
@@ -47,6 +47,7 @@ ENTRY(clear_page)
 	abi_ret_default
 
 ENDPROC(clear_page)
+EXPORT_SYMBOL(clear_page)
 
 /*
  * copy_page and copy_user_page are the same for non-cache-aliased configs.
@@ -89,6 +90,7 @@ ENTRY(copy_page)
 	abi_ret_default
 
 ENDPROC(copy_page)
+EXPORT_SYMBOL(copy_page)
 
 #ifdef CONFIG_MMU
 /*
@@ -367,6 +369,7 @@ ENTRY(__invalidate_icache_range)
 	abi_ret_default
 
 ENDPROC(__invalidate_icache_range)
+EXPORT_SYMBOL(__invalidate_icache_range)
 
 /*
  * void __flush_invalidate_dcache_range(ulong start, ulong size)
@@ -397,6 +400,7 @@ ENTRY(__flush_dcache_range)
 	abi_ret_default
 
 ENDPROC(__flush_dcache_range)
+EXPORT_SYMBOL(__flush_dcache_range)
 
 /*
  * void _invalidate_dcache_range(ulong start, ulong size)
@@ -411,6 +415,7 @@ ENTRY(__invalidate_dcache_range)
 	abi_ret_default
 
 ENDPROC(__invalidate_dcache_range)
+EXPORT_SYMBOL(__invalidate_dcache_range)
 
 /*
  * void _invalidate_icache_all(void)
diff --git a/arch/xtensa/platforms/iss/setup.c b/arch/xtensa/platforms/iss/setup.c
index d3433e1bb94e..0f1fe132691e 100644
--- a/arch/xtensa/platforms/iss/setup.c
+++ b/arch/xtensa/platforms/iss/setup.c
@@ -16,6 +16,7 @@
 #include <linux/notifier.h>
 #include <linux/panic_notifier.h>
 #include <linux/printk.h>
+#include <linux/reboot.h>
 #include <linux/string.h>
 
 #include <asm/platform.h>
@@ -24,26 +25,27 @@
 #include <platform/simcall.h>
 
 
-void platform_halt(void)
-{
-	pr_info(" ** Called platform_halt() **\n");
-	simc_exit(0);
-}
-
-void platform_power_off(void)
+static int iss_power_off(struct sys_off_data *unused)
 {
 	pr_info(" ** Called platform_power_off() **\n");
 	simc_exit(0);
+	return NOTIFY_DONE;
 }
 
-void platform_restart(void)
+static int iss_restart(struct notifier_block *this,
+		       unsigned long event, void *ptr)
 {
 	/* Flush and reset the mmu, simulate a processor reset, and
 	 * jump to the reset vector. */
 	cpu_reset();
-	/* control never gets here */
+
+	return NOTIFY_DONE;
 }
 
+static struct notifier_block iss_restart_block = {
+	.notifier_call = iss_restart,
+};
+
 static int
 iss_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
 {
@@ -82,4 +84,8 @@ void __init platform_setup(char **p_cmdline)
 	}
 
 	atomic_notifier_chain_register(&panic_notifier_list, &iss_panic_block);
+	register_restart_handler(&iss_restart_block);
+	register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
+				 SYS_OFF_PRIO_PLATFORM,
+				 iss_power_off, NULL);
 }
diff --git a/arch/xtensa/platforms/xt2000/setup.c b/arch/xtensa/platforms/xt2000/setup.c
index 0dc22c371614..258e01a51fd8 100644
--- a/arch/xtensa/platforms/xt2000/setup.c
+++ b/arch/xtensa/platforms/xt2000/setup.c
@@ -23,6 +23,7 @@
 #include <linux/platform_device.h>
 #include <linux/serial.h>
 #include <linux/serial_8250.h>
+#include <linux/timer.h>
 
 #include <asm/processor.h>
 #include <asm/platform.h>
@@ -41,51 +42,46 @@ static void led_print (int f, char *s)
 		    break;
 }
 
-void platform_halt(void)
-{
-	led_print (0, "  HALT  ");
-	local_irq_disable();
-	while (1);
-}
-
-void platform_power_off(void)
+static int xt2000_power_off(struct sys_off_data *unused)
 {
 	led_print (0, "POWEROFF");
 	local_irq_disable();
 	while (1);
+	return NOTIFY_DONE;
 }
 
-void platform_restart(void)
+static int xt2000_restart(struct notifier_block *this,
+			  unsigned long event, void *ptr)
 {
 	/* Flush and reset the mmu, simulate a processor reset, and
 	 * jump to the reset vector. */
 	cpu_reset();
-	/* control never gets here */
+
+	return NOTIFY_DONE;
 }
 
+static struct notifier_block xt2000_restart_block = {
+	.notifier_call = xt2000_restart,
+};
+
 void __init platform_setup(char** cmdline)
 {
 	led_print (0, "LINUX   ");
 }
 
-/* early initialization */
+/* Heartbeat. Let the LED blink. */
 
-void __init platform_init(bp_tag_t *first)
-{
-}
+static void xt2000_heartbeat(struct timer_list *unused);
 
-/* Heartbeat. Let the LED blink. */
+static DEFINE_TIMER(heartbeat_timer, xt2000_heartbeat);
 
-void platform_heartbeat(void)
+static void xt2000_heartbeat(struct timer_list *unused)
 {
-	static int i, t;
+	static int i;
 
-	if (--t < 0)
-	{
-		t = 59;
-		led_print(7, i ? ".": " ");
-		i ^= 1;
-	}
+	led_print(7, i ? "." : " ");
+	i ^= 1;
+	mod_timer(&heartbeat_timer, jiffies + HZ / 2);
 }
 
 //#define RS_TABLE_SIZE 2
@@ -143,7 +139,11 @@ static int __init xt2000_setup_devinit(void)
 {
 	platform_device_register(&xt2000_serial8250_device);
 	platform_device_register(&xt2000_sonic_device);
-
+	mod_timer(&heartbeat_timer, jiffies + HZ / 2);
+	register_restart_handler(&xt2000_restart_block);
+	register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
+				 SYS_OFF_PRIO_DEFAULT,
+				 xt2000_power_off, NULL);
 	return 0;
 }
 
diff --git a/arch/xtensa/platforms/xtfpga/setup.c b/arch/xtensa/platforms/xtfpga/setup.c
index c79c1d09ea86..a2432f081710 100644
--- a/arch/xtensa/platforms/xtfpga/setup.c
+++ b/arch/xtensa/platforms/xtfpga/setup.c
@@ -33,23 +33,17 @@
 #include <platform/lcd.h>
 #include <platform/hardware.h>
 
-void platform_halt(void)
-{
-	lcd_disp_at_pos(" HALT ", 0);
-	local_irq_disable();
-	while (1)
-		cpu_relax();
-}
-
-void platform_power_off(void)
+static int xtfpga_power_off(struct sys_off_data *unused)
 {
 	lcd_disp_at_pos("POWEROFF", 0);
 	local_irq_disable();
 	while (1)
 		cpu_relax();
+	return NOTIFY_DONE;
 }
 
-void platform_restart(void)
+static int xtfpga_restart(struct notifier_block *this,
+			  unsigned long event, void *ptr)
 {
 	/* Try software reset first. */
 	WRITE_ONCE(*(u32 *)XTFPGA_SWRST_VADDR, 0xdead);
@@ -58,9 +52,14 @@ void platform_restart(void)
 	 * simulate a processor reset, and jump to the reset vector.
 	 */
 	cpu_reset();
-	/* control never gets here */
+
+	return NOTIFY_DONE;
 }
 
+static struct notifier_block xtfpga_restart_block = {
+	.notifier_call = xtfpga_restart,
+};
+
 #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
 
 void __init platform_calibrate_ccount(void)
@@ -70,6 +69,14 @@ void __init platform_calibrate_ccount(void)
 
 #endif
 
+static void __init xtfpga_register_handlers(void)
+{
+	register_restart_handler(&xtfpga_restart_block);
+	register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
+				 SYS_OFF_PRIO_DEFAULT,
+				 xtfpga_power_off, NULL);
+}
+
 #ifdef CONFIG_USE_OF
 
 static void __init xtfpga_clk_setup(struct device_node *np)
@@ -134,6 +141,9 @@ static int __init machine_setup(void)
 	if ((eth = of_find_compatible_node(eth, NULL, "opencores,ethoc")))
 		update_local_mac(eth);
 	of_node_put(eth);
+
+	xtfpga_register_handlers();
+
 	return 0;
 }
 arch_initcall(machine_setup);
@@ -281,6 +291,8 @@ static int __init xtavnet_init(void)
 	pr_info("XTFPGA: Ethernet MAC %pM\n", ethoc_pdata.hwaddr);
 	ethoc_pdata.eth_clkfreq = *(long *)XTFPGA_CLKFRQ_VADDR;
 
+	xtfpga_register_handlers();
+
 	return 0;
 }