1 files changed, 281 insertions, 52 deletions

diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index 3fcd752d6146..aad83df89bac 100644
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -2,32 +2,183 @@
  * @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/errno.h>
 #include <linux/init.h>
+#include <linux/mutex.h>
 #include <linux/oprofile.h>
-#include <linux/errno.h>
+#include <linux/perf_event.h>
 #include <linux/slab.h>
 #include <linux/sysdev.h>
-#include <linux/mutex.h>
+#include <asm/stacktrace.h>
+#include <linux/uaccess.h>
+
+#include <asm/perf_event.h>
+#include <asm/ptrace.h>
 
-#include "op_counter.h"
-#include "op_arm_model.h"
+#ifdef CONFIG_HW_PERF_EVENTS
+/*
+ * Per performance monitor configuration as set via oprofilefs.
+ */
+struct op_counter_config {
+        unsigned long count;
+        unsigned long enabled;
+        unsigned long event;
+        unsigned long unit_mask;
+        unsigned long kernel;
+        unsigned long user;
+        struct perf_event_attr attr;
+};
 
-static struct op_arm_model_spec *op_arm_model;
 static int op_arm_enabled;
 static DEFINE_MUTEX(op_arm_mutex);
 
-struct op_counter_config *counter_config;
+static struct op_counter_config *counter_config;
+static struct perf_event **perf_events[nr_cpumask_bits];
+static int perf_num_counters;
+
+/*
+ * Overflow callback for oprofile.
+ */
+static void op_overflow_handler(struct perf_event *event, int unused,
+                        struct perf_sample_data *data, struct pt_regs *regs)
+{
+        int id;
+        u32 cpu = smp_processor_id();
+
+        for (id = 0; id < perf_num_counters; ++id)
+                if (perf_events[cpu][id] == event)
+                        break;
+
+        if (id != perf_num_counters)
+                oprofile_add_sample(regs, id);
+        else
+                pr_warning("oprofile: ignoring spurious overflow "
+                                "on cpu %u\n", cpu);
+}
+
+/*
+ * Called by op_arm_setup to create perf attributes to mirror the oprofile
+ * settings in counter_config. Attributes are created as `pinned' events and
+ * so are permanently scheduled on the PMU.
+ */
+static void op_perf_setup(void)
+{
+        int i;
+        u32 size = sizeof(struct perf_event_attr);
+        struct perf_event_attr *attr;
+
+        for (i = 0; i < perf_num_counters; ++i) {
+                attr = &counter_config[i].attr;
+                memset(attr, 0, size);
+                attr->type              = PERF_TYPE_RAW;
+                attr->size              = size;
+                attr->config            = counter_config[i].event;
+                attr->sample_period     = counter_config[i].count;
+                attr->pinned            = 1;
+        }
+}
+
+static int op_create_counter(int cpu, int event)
+{
+        int ret = 0;
+        struct perf_event *pevent;
+
+        if (!counter_config[event].enabled || (perf_events[cpu][event] != NULL))
+                return ret;
+
+        pevent = perf_event_create_kernel_counter(&counter_config[event].attr,
+                                                  cpu, -1,
+                                                  op_overflow_handler);
+
+        if (IS_ERR(pevent)) {
+                ret = PTR_ERR(pevent);
+        } else if (pevent->state != PERF_EVENT_STATE_ACTIVE) {
+                pr_warning("oprofile: failed to enable event %d "
+                                "on CPU %d\n", event, cpu);
+                ret = -EBUSY;
+        } else {
+                perf_events[cpu][event] = pevent;
+        }
+
+        return ret;
+}
+
+static void op_destroy_counter(int cpu, int event)
+{
+        struct perf_event *pevent = perf_events[cpu][event];
+
+        if (pevent) {
+                perf_event_release_kernel(pevent);
+                perf_events[cpu][event] = NULL;
+        }
+}
+
+/*
+ * Called by op_arm_start to create active perf events based on the
+ * perviously configured attributes.
+ */
+static int op_perf_start(void)
+{
+        int cpu, event, ret = 0;
+
+        for_each_online_cpu(cpu) {
+                for (event = 0; event < perf_num_counters; ++event) {
+                        ret = op_create_counter(cpu, event);
+                        if (ret)
+                                goto out;
+                }
+        }
+
+out:
+        return ret;
+}
+
+/*
+ * Called by op_arm_stop at the end of a profiling run.
+ */
+static void op_perf_stop(void)
+{
+        int cpu, event;
+
+        for_each_online_cpu(cpu)
+                for (event = 0; event < perf_num_counters; ++event)
+                        op_destroy_counter(cpu, event);
+}
+
+
+static char *op_name_from_perf_id(enum arm_perf_pmu_ids id)
+{
+        switch (id) {
+        case ARM_PERF_PMU_ID_XSCALE1:
+                return "arm/xscale1";
+        case ARM_PERF_PMU_ID_XSCALE2:
+                return "arm/xscale2";
+        case ARM_PERF_PMU_ID_V6:
+                return "arm/armv6";
+        case ARM_PERF_PMU_ID_V6MP:
+                return "arm/mpcore";
+        case ARM_PERF_PMU_ID_CA8:
+                return "arm/armv7";
+        case ARM_PERF_PMU_ID_CA9:
+                return "arm/armv7-ca9";
+        default:
+                return NULL;
+        }
+}
 
 static int op_arm_create_files(struct super_block *sb, struct dentry *root)
 {
         unsigned int i;
 
-        for (i = 0; i < op_arm_model->num_counters; i++) {
+        for (i = 0; i < perf_num_counters; i++) {
                 struct dentry *dir;
                 char buf[4];
 
@@ -46,12 +197,10 @@ static int op_arm_create_files(struct super_block *sb, struct dentry *root)
 
 static int op_arm_setup(void)
 {
-        int ret;
-
         spin_lock(&oprofilefs_lock);
-        ret = op_arm_model->setup_ctrs();
+        op_perf_setup();
         spin_unlock(&oprofilefs_lock);
-        return ret;
+        return 0;
 }
 
 static int op_arm_start(void)
@@ -60,8 +209,9 @@ static int op_arm_start(void)
 
         mutex_lock(&op_arm_mutex);
         if (!op_arm_enabled) {
-                ret = op_arm_model->start();
-                op_arm_enabled = !ret;
+                ret = 0;
+                op_perf_start();
+                op_arm_enabled = 1;
         }
         mutex_unlock(&op_arm_mutex);
         return ret;
@@ -71,7 +221,7 @@ static void op_arm_stop(void)
 {
         mutex_lock(&op_arm_mutex);
         if (op_arm_enabled)
-                op_arm_model->stop();
+                op_perf_stop();
         op_arm_enabled = 0;
         mutex_unlock(&op_arm_mutex);
 }
@@ -81,7 +231,7 @@ static int op_arm_suspend(struct sys_device *dev, pm_message_t state)
 {
         mutex_lock(&op_arm_mutex);
         if (op_arm_enabled)
-                op_arm_model->stop();
+                op_perf_stop();
         mutex_unlock(&op_arm_mutex);
         return 0;
 }
@@ -89,7 +239,7 @@ static int op_arm_suspend(struct sys_device *dev, pm_message_t state)
 static int op_arm_resume(struct sys_device *dev)
 {
         mutex_lock(&op_arm_mutex);
-        if (op_arm_enabled && op_arm_model->start())
+        if (op_arm_enabled && op_perf_start())
                 op_arm_enabled = 0;
         mutex_unlock(&op_arm_mutex);
         return 0;
@@ -126,58 +276,137 @@ static void  exit_driverfs(void)
 #define exit_driverfs() do { } while (0)
 #endif /* CONFIG_PM */
 
-int __init oprofile_arch_init(struct oprofile_operations *ops)
+static int report_trace(struct stackframe *frame, void *d)
 {
-        struct op_arm_model_spec *spec = NULL;
-        int ret = -ENODEV;
+        unsigned int *depth = d;
 
-        ops->backtrace = arm_backtrace;
+        if (*depth) {
+                oprofile_add_trace(frame->pc);
+                (*depth)--;
+        }
 
-#ifdef CONFIG_CPU_XSCALE
-        spec = &op_xscale_spec;
-#endif
+        return *depth == 0;
+}
 
-#ifdef CONFIG_OPROFILE_ARMV6
-        spec = &op_armv6_spec;
-#endif
+/*
+ * 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));
 
-#ifdef CONFIG_OPROFILE_MPCORE
-        spec = &op_mpcore_spec;
-#endif
+static struct frame_tail* user_backtrace(struct frame_tail *tail)
+{
+        struct frame_tail buftail[2];
 
-#ifdef CONFIG_OPROFILE_ARMV7
-        spec = &op_armv7_spec;
-#endif
+        /* 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;
 
-        if (spec) {
-                ret = spec->init();
-                if (ret < 0)
-                        return ret;
+        oprofile_add_trace(buftail[0].lr);
 
-                counter_config = kcalloc(spec->num_counters, sizeof(struct op_counter_config),
-                                         GFP_KERNEL);
-                if (!counter_config)
-                        return -ENOMEM;
+        /* frame pointers should strictly progress back up the stack
+         * (towards higher addresses) */
+        if (tail >= 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->ARM_fp) - 1;
+
+        if (!user_mode(regs)) {
+                struct stackframe frame;
+                frame.fp = regs->ARM_fp;
+                frame.sp = regs->ARM_sp;
+                frame.lr = regs->ARM_lr;
+                frame.pc = regs->ARM_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)
+{
+        int cpu, ret = 0;
+
+        perf_num_counters = armpmu_get_max_events();
+
+        counter_config = kcalloc(perf_num_counters,
+                        sizeof(struct op_counter_config), GFP_KERNEL);
 
-                op_arm_model = spec;
-                init_driverfs();
-                ops->create_files = op_arm_create_files;
-                ops->setup = op_arm_setup;
-                ops->shutdown = op_arm_stop;
-                ops->start = op_arm_start;
-                ops->stop = op_arm_stop;
-                ops->cpu_type = op_arm_model->name;
-                printk(KERN_INFO "oprofile: using %s\n", spec->name);
+        if (!counter_config) {
+                pr_info("oprofile: failed to allocate %d "
+                                "counters\n", perf_num_counters);
+                return -ENOMEM;
         }
 
+        for_each_possible_cpu(cpu) {
+                perf_events[cpu] = kcalloc(perf_num_counters,
+                                sizeof(struct perf_event *), GFP_KERNEL);
+                if (!perf_events[cpu]) {
+                        pr_info("oprofile: failed to allocate %d perf events "
+                                        "for cpu %d\n", perf_num_counters, cpu);
+                        while (--cpu >= 0)
+                                kfree(perf_events[cpu]);
+                        return -ENOMEM;
+                }
+        }
+
+        init_driverfs();
+        ops->backtrace          = arm_backtrace;
+        ops->create_files       = op_arm_create_files;
+        ops->setup              = op_arm_setup;
+        ops->start              = op_arm_start;
+        ops->stop               = op_arm_stop;
+        ops->shutdown           = op_arm_stop;
+        ops->cpu_type           = op_name_from_perf_id(armpmu_get_pmu_id());
+
+        if (!ops->cpu_type)
+                ret = -ENODEV;
+        else
+                pr_info("oprofile: using %s\n", ops->cpu_type);
+
         return ret;
 }
 
 void oprofile_arch_exit(void)
 {
-        if (op_arm_model) {
+        int cpu, id;
+        struct perf_event *event;
+
+        if (*perf_events) {
                 exit_driverfs();
-                op_arm_model = NULL;
+                for_each_possible_cpu(cpu) {
+                        for (id = 0; id < perf_num_counters; ++id) {
+                                event = perf_events[cpu][id];
+                                if (event != NULL)
+                                        perf_event_release_kernel(event);
+                        }
+                        kfree(perf_events[cpu]);
+                }
         }
-        kfree(counter_config);
+
+        if (counter_config)
+                kfree(counter_config);
+}
+#else
+int __init oprofile_arch_init(struct oprofile_operations *ops)
+{
+        pr_info("oprofile: hardware counters not available\n");
+        return -ENODEV;
 }
+void oprofile_arch_exit(void) {}
+#endif /* CONFIG_HW_PERF_EVENTS */