Re: [RFC][PATCH 3/3]perf/powerpc :add support for sampling intr machine state

[AnjuTSudhakar <anju@linux.vnet.ibm.com>]

On Tuesday 20 October 2015 09:50 AM, Madhavan Srinivasan wrote:
>
> On Monday 19 October 2015 05:48 PM, Anju T wrote:
>> From: Anju <anju@linux.vnet.ibm.com>
>>
>> The registers to sample are passed through the sample_regs_intr bitmask.
>> The name and bit position for each register is defined in asm/perf_regs.h.
>> This feature can be enabled by using -I option with perf  record command.
>> To display the sampled register values use perf script -D.
>> The kernel uses the "PERF" register ids to find offset of the register in 'struct pt_regs'.
>> CONFIG_HAVE_PERF_REGS will enable sampling of the interrupted machine state.
>>
>> Signed-off-by: Anju T <anju@linux.vnet.ibm.com>
>> ---
>>   arch/powerpc/Kconfig          |  1 +
>>   arch/powerpc/perf/Makefile    |  2 +-
>>   arch/powerpc/perf/perf_regs.c | 85 +++++++++++++++++++++++++++++++++++++++++++
>>   tools/perf/config/Makefile    |  4 ++
>>   4 files changed, 91 insertions(+), 1 deletion(-)
>>   create mode 100644 arch/powerpc/perf/perf_regs.c
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 9a7057e..c4ce60d 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -119,6 +119,7 @@ config PPC
>>   	select GENERIC_ATOMIC64 if PPC32
>>   	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
>>   	select HAVE_PERF_EVENTS
>> +	select HAVE_PERF_REGS
>>   	select HAVE_REGS_AND_STACK_ACCESS_API
>>   	select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64
>>   	select ARCH_WANT_IPC_PARSE_VERSION
>> diff --git a/arch/powerpc/perf/Makefile b/arch/powerpc/perf/Makefile
>> index f9c083a..8e7f545 100644
>> --- a/arch/powerpc/perf/Makefile
>> +++ b/arch/powerpc/perf/Makefile
>> @@ -7,7 +7,7 @@ obj64-$(CONFIG_PPC_PERF_CTRS)	+= power4-pmu.o ppc970-pmu.o power5-pmu.o \
>>   				   power5+-pmu.o power6-pmu.o power7-pmu.o \
>>   				   power8-pmu.o
>>   obj32-$(CONFIG_PPC_PERF_CTRS)	+= mpc7450-pmu.o
>> -
>> +obj-$(CONFIG_PERF_EVENTS)      	+= perf_regs.o
>>   obj-$(CONFIG_FSL_EMB_PERF_EVENT) += core-fsl-emb.o
>>   obj-$(CONFIG_FSL_EMB_PERF_EVENT_E500) += e500-pmu.o e6500-pmu.o
>>
>> diff --git a/arch/powerpc/perf/perf_regs.c b/arch/powerpc/perf/perf_regs.c
>> new file mode 100644
>> index 0000000..7a71de2
>> --- /dev/null
>> +++ b/arch/powerpc/perf/perf_regs.c
>> @@ -0,0 +1,85 @@
>> +#include <linux/errno.h>
>> +#include <linux/kernel.h>
>> +#include <linux/sched.h>
>> +#include <linux/perf_event.h>
>> +#include <linux/bug.h>
>> +#include <linux/stddef.h>
>> +#include <asm/ptrace.h>
>> +#include <asm/perf_regs.h>
>> +
>> +#define PT_REGS_OFFSET(id, r) [id] = offsetof(struct pt_regs, r)
>> +
>> +#define REG_RESERVED (~((1ULL << PERF_REG_POWERPC_MAX) - 1))
>> +
>> +static unsigned int pt_regs_offset[PERF_REG_POWERPC_MAX] = {
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR0, gpr[0]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR1, gpr[1]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR2, gpr[2]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR3, gpr[3]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR4, gpr[4]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR5, gpr[5]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR6, gpr[6]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR7, gpr[7]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR8, gpr[8]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR9, gpr[9]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR10, gpr[10]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR11, gpr[11]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR12, gpr[12]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR13, gpr[13]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR14, gpr[14]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR15, gpr[15]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR16, gpr[16]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR17, gpr[17]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR18, gpr[18]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR19, gpr[19]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR20, gpr[20]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR21, gpr[21]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR22, gpr[22]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR23, gpr[23]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR24, gpr[24]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR25, gpr[25]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR26, gpr[26]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR27, gpr[27]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR28, gpr[28]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR29, gpr[29]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR30, gpr[30]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_GPR31, gpr[31]),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_NIP, nip),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_MSR, msr),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_ORIG_R3, orig_gpr3),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_CTR, ctr),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_LNK, link),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_XER, xer),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_CCR, ccr),
>> +#ifdef __powerpc64__
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_SOFTE, softe),
>> +#else
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_MQ, mq),
>> +#endif
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_TRAP, trap),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_DAR, dar),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_DSISR, dsisr),
>> +	PT_REGS_OFFSET(PERF_REG_POWERPC_RESULT, result),
>> +};
>> +u64 perf_reg_value(struct pt_regs *regs, int idx)
>> +{
>> +	if (WARN_ON_ONCE(idx >= PERF_REG_POWERPC_MAX))
>> +		return 0;
>> +	return regs_get_register(regs, pt_regs_offset[idx]);
>> +}
>> +int perf_reg_validate(u64 mask)
>> +{
>> +	if (!mask || mask & REG_RESERVED)
>> +		return -EINVAL;
>> +	return 0;
>> +}
>> +u64 perf_reg_abi(struct task_struct *task)
>> +{
>> +	return PERF_SAMPLE_REGS_ABI_64;
>> +}
>> +void perf_get_regs_user(struct perf_regs *regs_user,
>> +			struct pt_regs *regs,
>> +			struct pt_regs *regs_user_copy)
>> +{
> Kindly add comment to update the function when
> enabling perf_sample_reg_user.
>
> Maddy
Ok . will add that.
>> +	return;
>> +}
>> diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
>> index 827557f..4da9190 100644
>> --- a/tools/perf/config/Makefile
>> +++ b/tools/perf/config/Makefile
>> @@ -22,6 +22,10 @@ include $(src-perf)/config/Makefile.arch
>>   $(call detected_var,ARCH)
>>
>>   NO_PERF_REGS := 1
>> +#Additional ARCH settings for ppc64
>> +ifeq ($(ARCH),powerpc)
>> +	NO_PERF_REGS :=0
>> +endif
>>
>>   # Additional ARCH settings for x86
>>   ifeq ($(ARCH),x86)
Thanks
Anju