[PATCH] arm64: add OProfile support
From: Ding Tianhong
Date: Sat Apr 26 2014 - 04:40:27 EST
Add OProfile support for arm64, using the perf backend, and failing back
to generic timer based sampling if PMU interrupt is not supported.
I have test this patch on Cortex-A53 and Cortex-A57 motherboard, the OProfile
could work well by PMU irq or arch timer irq.
Signed-off-by: Xinwei Hu <huxinwei@xxxxxxxxxx>
Signed-off-by: Ding Tianhong <dingtianhong@xxxxxxxxxx>
---
arch/arm64/Kconfig | 1 +
arch/arm64/Makefile | 2 +
arch/arm64/include/asm/stacktrace.h | 1 +
arch/arm64/kernel/perf_event.c | 13 ++++-
arch/arm64/oprofile/Makefile | 13 +++++
arch/arm64/oprofile/common.c | 106 ++++++++++++++++++++++++++++++++++++
6 files changed, 135 insertions(+), 1 deletion(-)
create mode 100644 arch/arm64/oprofile/Makefile
create mode 100644 arch/arm64/oprofile/common.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e6e4d37..f711445 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -40,6 +40,7 @@ config ARM64
select HAVE_HW_BREAKPOINT if PERF_EVENTS
select HAVE_MEMBLOCK
select HAVE_PATA_PLATFORM
+ select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 2fceb71..6bb3d66 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -48,6 +48,8 @@ core-$(CONFIG_XEN) += arch/arm64/xen/
libs-y := arch/arm64/lib/ $(libs-y)
libs-y += $(LIBGCC)
+drivers-$(CONFIG_OPROFILE) += arch/arm64/oprofile/
+
# Default target when executing plain make
KBUILD_IMAGE := Image.gz
KBUILD_DTBS := dtbs
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 7318f6d..fec7e84 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -19,6 +19,7 @@
struct stackframe {
unsigned long fp;
unsigned long sp;
+ unsigned long lr;
unsigned long pc;
};
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index baf5afb..a8fd1c1 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -51,6 +51,15 @@ static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events);
/* Set at runtime when we know what CPU type we are. */
static struct arm_pmu *cpu_pmu;
+const char *perf_pmu_name(void)
+{
+ if (!cpu_pmu)
+ return NULL;
+
+ return cpu_pmu->name;
+}
+EXPORT_SYMBOL_GPL(perf_pmu_name);
+
int
armpmu_get_max_events(void)
{
@@ -640,7 +649,7 @@ enum armv8_pmuv3_perf_types {
ARMV8_PMUV3_PERFCTR_L1_DCACHE_REFILL = 0x03,
ARMV8_PMUV3_PERFCTR_L1_DCACHE_ACCESS = 0x04,
ARMV8_PMUV3_PERFCTR_PC_BRANCH_MIS_PRED = 0x10,
- ARMV8_PMUV3_PERFCTR_CLOCK_CYCLES = 0x11,
+ ARMV8_PMUV3_PERFCTR_CPU_CYCLES = 0x11,
ARMV8_PMUV3_PERFCTR_PC_BRANCH_PRED = 0x12,
/* At least one of the following is required. */
@@ -672,6 +681,8 @@ enum armv8_pmuv3_perf_types {
ARMV8_PMUV3_PERFCTR_BUS_ACCESS = 0x19,
ARMV8_PMUV3_PERFCTR_MEM_ERROR = 0x1A,
ARMV8_PMUV3_PERFCTR_BUS_CYCLES = 0x1D,
+
+ ARMV8_PMUV3_PERFCTR_CLOCK_CYCLES = 0XFF,
};
/* PMUv3 HW events mapping. */
diff --git a/arch/arm64/oprofile/Makefile b/arch/arm64/oprofile/Makefile
new file mode 100644
index 0000000..b2215c6
--- /dev/null
+++ b/arch/arm64/oprofile/Makefile
@@ -0,0 +1,13 @@
+obj-$(CONFIG_OPROFILE) += oprofile.o
+
+DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
+ oprof.o cpu_buffer.o buffer_sync.o \
+ event_buffer.o oprofile_files.o \
+ oprofilefs.o oprofile_stats.o \
+ timer_int.o )
+
+ifeq ($(CONFIG_HW_PERF_EVENTS),y)
+DRIVER_OBJS += $(addprefix ../../../drivers/oprofile/, oprofile_perf.o)
+endif
+
+oprofile-y := $(DRIVER_OBJS) common.o
diff --git a/arch/arm64/oprofile/common.c b/arch/arm64/oprofile/common.c
new file mode 100644
index 0000000..7d1c19c
--- /dev/null
+++ b/arch/arm64/oprofile/common.c
@@ -0,0 +1,106 @@
+/**
+ * @file common.c
+ *
+ * @remark Copyright 2004 Oprofile Authors
+ * @remark Copyright 2010 ARM Ltd.
+ * @remark Read the file COPYING
+ *
+ * @author Zwane Mwaikambo
+ * @author Will Deacon [move to perf]
+ */
+
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/oprofile.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <asm/stacktrace.h>
+#include <linux/uaccess.h>
+
+#include <asm/perf_event.h>
+#include <asm/ptrace.h>
+
+#ifdef CONFIG_HW_PERF_EVENTS
+
+char *op_name_from_perf_id(void)
+{
+ return perf_pmu_name();
+}
+#endif
+
+static int report_trace(struct stackframe *frame, void *d)
+{
+ unsigned int *depth = d;
+
+ if (*depth) {
+ oprofile_add_trace(frame->pc);
+ (*depth)--;
+ }
+
+ return *depth == 0;
+}
+
+/*
+ * The registers we're interested in are at the end of the variable
+ * length saved register structure. The fp points at the end of this
+ * structure so the address of this struct is:
+ * (struct frame_tail *)(xxx->fp)-1
+ */
+struct frame_tail {
+ struct frame_tail *fp;
+ unsigned long sp;
+ unsigned long lr;
+} __attribute__((packed));
+
+static struct frame_tail *user_backtrace(struct frame_tail *tail)
+{
+ struct frame_tail buftail[2];
+
+ /* Also check accessibility of one struct frame_tail beyond */
+ if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
+ return NULL;
+ if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
+ return NULL;
+
+ oprofile_add_trace(buftail[0].lr);
+
+ /* frame pointers should strictly progress back up the stack
+ * (towards higher addresses) */
+ if (tail + 1 >= buftail[0].fp)
+ return NULL;
+
+ return buftail[0].fp-1;
+}
+
+static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
+{
+ struct frame_tail *tail = ((struct frame_tail *) regs->regs[29]) - 1;
+
+ if (!user_mode(regs)) {
+ struct stackframe frame;
+ frame.fp = regs->regs[29];
+ frame.sp = regs->sp;
+ frame.lr = regs->regs[30];
+ frame.pc = regs->pc;
+ walk_stackframe(&frame, report_trace, &depth);
+ return;
+ }
+
+ while (depth-- && tail && !((unsigned long) tail & 3))
+ tail = user_backtrace(tail);
+}
+
+int __init oprofile_arch_init(struct oprofile_operations *ops)
+{
+ /* provide backtrace support also in timer mode: */
+ ops->backtrace = arm_backtrace;
+
+ return oprofile_perf_init(ops);
+}
+
+void oprofile_arch_exit(void)
+{
+ oprofile_perf_exit();
+}
--
1.8.0
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