[PATCH V2 3/3] perf/powerpc :add support for sampling intr machine state

From: Anju T
Date: Mon Oct 26 2015 - 08:45:28 EST


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@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/perf/Makefile | 1 +
arch/powerpc/perf/perf_regs.c | 87 +++++++++++++++++++++++++++++++++++++++++++
tools/perf/config/Makefile | 5 +++
4 files changed, 94 insertions(+)
create mode 100644 arch/powerpc/perf/perf_regs.c

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5ef2711..768d700 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -116,6 +116,7 @@ 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..0d53815 100644
--- a/arch/powerpc/perf/Makefile
+++ b/arch/powerpc/perf/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_FSL_EMB_PERF_EVENT) += core-fsl-emb.o
obj-$(CONFIG_FSL_EMB_PERF_EVENT_E500) += e500-pmu.o e6500-pmu.o

obj-$(CONFIG_HV_PERF_CTRS) += hv-24x7.o hv-gpci.o hv-common.o
+obj-$(CONFIG_PERF_EVENTS) += perf_regs.o

obj-$(CONFIG_PPC64) += $(obj64-y)
obj-$(CONFIG_PPC32) += $(obj32-y)
diff --git a/arch/powerpc/perf/perf_regs.c b/arch/powerpc/perf/perf_regs.c
new file mode 100644
index 0000000..2474dc4
--- /dev/null
+++ b/arch/powerpc/perf/perf_regs.c
@@ -0,0 +1,87 @@
+#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)
+{
+ return;
+ /*TODO :Update this function when
+ PERF_SAMPLE_REGS_USER is enabled */
+}
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index 094ddae..64e5af3 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -23,6 +23,11 @@ $(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)
$(call detected,CONFIG_X86)
--
2.1.0

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