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

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

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.

arch/xtensa/boot/boot-redboot/Makefile

@@ -6,24 +6,23 @@
 
 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) $(OBJCOPY_ARGS) -R .comment \
 		--add-section image=$< \
 		--set-section-flags image=contents,alloc,load,load,data \
 		$(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 $< $@

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 */

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>
 
 /*

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. */

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

arch/xtensa/include/asm/platform.h

@@ -27,31 +27,11 @@ 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)
  */

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__)
 
 /*

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);
 }