[PATCH 6/7] sh: oprofile: Use perf-events oprofile backend

From: Matt Fleming
Date: Mon Oct 04 2010 - 16:44:52 EST


Now that we've got a generic perf-events based oprofile backend we might
as well make use of it seeing as SH doesn't do anything special with its
oprofile backend. Also introduce a new CONFIG_HW_PERF_EVENTS symbol so
that we can fallback to using the timer interrupt for oprofile if the
CPU doesn't support perf events.

Signed-off-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxx>
---
arch/sh/Kconfig | 13 +++++
arch/sh/oprofile/Makefile | 4 ++
arch/sh/oprofile/common.c | 109 ++++---------------------------------------
arch/sh/oprofile/op_impl.h | 33 -------------
4 files changed, 28 insertions(+), 131 deletions(-)
delete mode 100644 arch/sh/oprofile/op_impl.h

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 33990fa..35b6c3f 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -249,6 +249,11 @@ config ARCH_SHMOBILE
select PM
select PM_RUNTIME

+config CPU_HAS_PMU
+ depends on CPU_SH4 || CPU_SH4A
+ default y
+ bool
+
if SUPERH32

choice
@@ -738,6 +743,14 @@ config GUSA_RB
LLSC, this should be more efficient than the other alternative of
disabling interrupts around the atomic sequence.

+config HW_PERF_EVENTS
+ bool "Enable hardware performance counter support for perf events"
+ depends on PERF_EVENTS && CPU_HAS_PMU
+ default y
+ help
+ Enable hardware performance counter support for perf events. If
+ disabled, perf events will use software events only.
+
source "drivers/sh/Kconfig"

endmenu
diff --git a/arch/sh/oprofile/Makefile b/arch/sh/oprofile/Makefile
index 4886c5c..e85aae7 100644
--- a/arch/sh/oprofile/Makefile
+++ b/arch/sh/oprofile/Makefile
@@ -6,4 +6,8 @@ DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
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 backtrace.o
diff --git a/arch/sh/oprofile/common.c b/arch/sh/oprofile/common.c
index ac60493..449f842 100644
--- a/arch/sh/oprofile/common.c
+++ b/arch/sh/oprofile/common.c
@@ -18,113 +18,26 @@
#include <linux/errno.h>
#include <linux/smp.h>
#include <asm/processor.h>
-#include "op_impl.h"
-
-static struct op_sh_model *model;
-
-static struct op_counter_config ctr[20];

+#ifdef CONFIG_HW_PERF_EVENTS
extern void sh_backtrace(struct pt_regs * const regs, unsigned int depth);

-static int op_sh_setup(void)
-{
- /* Pre-compute the values to stuff in the hardware registers. */
- model->reg_setup(ctr);
-
- /* Configure the registers on all cpus. */
- on_each_cpu(model->cpu_setup, NULL, 1);
-
- return 0;
-}
-
-static int op_sh_create_files(struct super_block *sb, struct dentry *root)
-{
- int i, ret = 0;
-
- for (i = 0; i < model->num_counters; i++) {
- struct dentry *dir;
- char buf[4];
-
- snprintf(buf, sizeof(buf), "%d", i);
- dir = oprofilefs_mkdir(sb, root, buf);
-
- ret |= oprofilefs_create_ulong(sb, dir, "enabled", &ctr[i].enabled);
- ret |= oprofilefs_create_ulong(sb, dir, "event", &ctr[i].event);
- ret |= oprofilefs_create_ulong(sb, dir, "kernel", &ctr[i].kernel);
- ret |= oprofilefs_create_ulong(sb, dir, "user", &ctr[i].user);
-
- if (model->create_files)
- ret |= model->create_files(sb, dir);
- else
- ret |= oprofilefs_create_ulong(sb, dir, "count", &ctr[i].count);
-
- /* Dummy entries */
- ret |= oprofilefs_create_ulong(sb, dir, "unit_mask", &ctr[i].unit_mask);
- }
-
- return ret;
-}
-
-static int op_sh_start(void)
-{
- /* Enable performance monitoring for all counters. */
- on_each_cpu(model->cpu_start, NULL, 1);
-
- return 0;
-}
-
-static void op_sh_stop(void)
-{
- /* Disable performance monitoring for all counters. */
- on_each_cpu(model->cpu_stop, NULL, 1);
-}
-
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
- struct op_sh_model *lmodel = NULL;
- int ret;
-
- /*
- * Always assign the backtrace op. If the counter initialization
- * fails, we fall back to the timer which will still make use of
- * this.
- */
ops->backtrace = sh_backtrace;

- /*
- * XXX
- *
- * All of the SH7750/SH-4A counters have been converted to perf,
- * this infrastructure hook is left for other users until they've
- * had a chance to convert over, at which point all of this
- * will be deleted.
- */
-
- if (!lmodel)
- return -ENODEV;
- if (!(current_cpu_data.flags & CPU_HAS_PERF_COUNTER))
- return -ENODEV;
-
- ret = lmodel->init();
- if (unlikely(ret != 0))
- return ret;
-
- model = lmodel;
-
- ops->setup = op_sh_setup;
- ops->create_files = op_sh_create_files;
- ops->start = op_sh_start;
- ops->stop = op_sh_stop;
- ops->cpu_type = lmodel->cpu_type;
-
- printk(KERN_INFO "oprofile: using %s performance monitoring.\n",
- lmodel->cpu_type);
-
- return 0;
+ return oprofile_perf_init(ops);
}

void oprofile_arch_exit(void)
{
- if (model && model->exit)
- model->exit();
+ oprofile_perf_exit();
+}
+#else
+int __init oprofile_arch_init(struct oprofile_operations *ops)
+{
+ pr_info("oprofile: hardware counters not available\n");
+ return -ENODEV;
}
+void __exit oprofile_arch_exit(void) {}
+#endif /* CONFIG_HW_PERF_EVENTS */
diff --git a/arch/sh/oprofile/op_impl.h b/arch/sh/oprofile/op_impl.h
deleted file mode 100644
index 1244479..0000000
--- a/arch/sh/oprofile/op_impl.h
+++ /dev/null
@@ -1,33 +0,0 @@
-#ifndef __OP_IMPL_H
-#define __OP_IMPL_H
-
-/* Per-counter configuration as set via oprofilefs. */
-struct op_counter_config {
- unsigned long enabled;
- unsigned long event;
-
- unsigned long count;
-
- /* Dummy values for userspace tool compliance */
- unsigned long kernel;
- unsigned long user;
- unsigned long unit_mask;
-};
-
-/* Per-architecture configury and hooks. */
-struct op_sh_model {
- void (*reg_setup)(struct op_counter_config *);
- int (*create_files)(struct super_block *sb, struct dentry *dir);
- void (*cpu_setup)(void *dummy);
- int (*init)(void);
- void (*exit)(void);
- void (*cpu_start)(void *args);
- void (*cpu_stop)(void *args);
- char *cpu_type;
- unsigned char num_counters;
-};
-
-/* arch/sh/oprofile/common.c */
-extern void sh_backtrace(struct pt_regs * const regs, unsigned int depth);
-
-#endif /* __OP_IMPL_H */
--
1.7.1

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