diff options
| -rw-r--r-- | tools/perf/arch/arm/Makefile | 1 | ||||
| -rw-r--r-- | tools/perf/arch/arm/include/perf_regs.h | 2 | ||||
| -rw-r--r-- | tools/perf/arch/arm/tests/regs_load.S | 58 |
3 files changed, 61 insertions, 0 deletions
diff --git a/tools/perf/arch/arm/Makefile b/tools/perf/arch/arm/Makefile index 67e9b3d38e89..9b8f87e8c7b9 100644 --- a/tools/perf/arch/arm/Makefile +++ b/tools/perf/arch/arm/Makefile @@ -4,4 +4,5 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o endif ifndef NO_LIBUNWIND LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libunwind.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/regs_load.o endif diff --git a/tools/perf/arch/arm/include/perf_regs.h b/tools/perf/arch/arm/include/perf_regs.h index bcca511f5884..33abcfa3057c 100644 --- a/tools/perf/arch/arm/include/perf_regs.h +++ b/tools/perf/arch/arm/include/perf_regs.h @@ -5,6 +5,8 @@ #include <linux/types.h> #include <asm/perf_regs.h> +void perf_regs_load(u64 *regs); + #define PERF_REGS_MASK ((1ULL << PERF_REG_ARM_MAX) - 1) #define PERF_REG_IP PERF_REG_ARM_PC #define PERF_REG_SP PERF_REG_ARM_SP diff --git a/tools/perf/arch/arm/tests/regs_load.S b/tools/perf/arch/arm/tests/regs_load.S new file mode 100644 index 000000000000..e09e983946fe --- /dev/null +++ b/tools/perf/arch/arm/tests/regs_load.S @@ -0,0 +1,58 @@ +#include <linux/linkage.h> + +#define R0 0x00 +#define R1 0x08 +#define R2 0x10 +#define R3 0x18 +#define R4 0x20 +#define R5 0x28 +#define R6 0x30 +#define R7 0x38 +#define R8 0x40 +#define R9 0x48 +#define SL 0x50 +#define FP 0x58 +#define IP 0x60 +#define SP 0x68 +#define LR 0x70 +#define PC 0x78 + +/* + * Implementation of void perf_regs_load(u64 *regs); + * + * This functions fills in the 'regs' buffer from the actual registers values, + * in the way the perf built-in unwinding test expects them: + * - the PC at the time at the call to this function. Since this function + * is called using a bl instruction, the PC value is taken from LR. + * The built-in unwinding test then unwinds the call stack from the dwarf + * information in unwind__get_entries. + * + * Notes: + * - the 8 bytes stride in the registers offsets comes from the fact + * that the registers are stored in an u64 array (u64 *regs), + * - the regs buffer needs to be zeroed before the call to this function, + * in this case using a calloc in dwarf-unwind.c. + */ + +.text +.type perf_regs_load,%function +ENTRY(perf_regs_load) + str r0, [r0, #R0] + str r1, [r0, #R1] + str r2, [r0, #R2] + str r3, [r0, #R3] + str r4, [r0, #R4] + str r5, [r0, #R5] + str r6, [r0, #R6] + str r7, [r0, #R7] + str r8, [r0, #R8] + str r9, [r0, #R9] + str sl, [r0, #SL] + str fp, [r0, #FP] + str ip, [r0, #IP] + str sp, [r0, #SP] + str lr, [r0, #LR] + str lr, [r0, #PC] // store pc as lr in order to skip the call + // to this function + mov pc, lr +ENDPROC(perf_regs_load) |