sh: oprofile: Use perf-events oprofile backend

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.

Also, to avoid a section mismatch warning we need to annotate
oprofile_arch_exit() with an __exit marker.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>

4 files changed, 40 insertions, 125 deletions

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 33990fa95af0..35b6c3f85173 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 4886c5c1786c..e85aae73e3dc 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 ac604937f3ee..e10d89376f9b 100644
--- a/arch/sh/oprofile/common.c
+++ b/arch/sh/oprofile/common.c
@@ -17,114 +17,45 @@
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/smp.h>
+#include <linux/perf_event.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)
+char *op_name_from_perf_id(void)
 {
-        int i, ret = 0;
+        const char *pmu;
+        char buf[20];
+        int size;
 
-        for (i = 0; i < model->num_counters; i++) {
-                struct dentry *dir;
-                char buf[4];
+        pmu = perf_pmu_name();
+        if (!pmu)
+                return NULL;
 
-                snprintf(buf, sizeof(buf), "%d", i);
-                dir = oprofilefs_mkdir(sb, root, buf);
+        size = snprintf(buf, sizeof(buf), "sh/%s", pmu);
+        if (size > -1 && size < sizeof(buf))
+                return 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;
+        return NULL;
 }
 
-static int op_sh_start(void)
+int __init oprofile_arch_init(struct oprofile_operations *ops)
 {
-        /* Enable performance monitoring for all counters.  */
-        on_each_cpu(model->cpu_start, NULL, 1);
+        ops->backtrace = sh_backtrace;
 
-        return 0;
+        return oprofile_perf_init(ops);
 }
 
-static void op_sh_stop(void)
+void __exit oprofile_arch_exit(void)
 {
-        /* Disable performance monitoring for all counters.  */
-        on_each_cpu(model->cpu_stop, NULL, 1);
+        oprofile_perf_exit();
 }
-
+#else
 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;
-}
-
-void oprofile_arch_exit(void)
-{
-        if (model && model->exit)
-                model->exit();
+        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 1244479ceb29..000000000000
--- 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 */