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perf tests: Introduce perf_regs_load function on ARM

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Introducing perf_regs_load function, which is going
to be used for dwarf unwind test in following patches.

It takes single argument as a pointer to the regs dump
buffer and populates it with current registers values.

Signed-off-by: Jean Pihet <jean.pihet@linaro.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1400229672-16104-2-git-send-email-jean.pihet@linaro.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
This commit is contained in:
Jean Pihet 2014-05-16 10:41:10 +02:00 committed by Jiri Olsa
parent 21a8b756b8
commit 3418f9667e
3 changed files with 61 additions and 0 deletions
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1
tools/perf/arch/arm/Makefile
View File

@ -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

2
tools/perf/arch/arm/include/perf_regs.h
View File

@ -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

58
tools/perf/arch/arm/tests/regs_load.S Normal file
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@ -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)