perf: Add helper function to return number of counters

[deliverable/linux.git] / arch / arm / oprofile / common.c

diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index 0691176899ffc24f0a176d154a34f5b7200c6047..1e971a7fcf82685f5651cd8114b20d59efbde166 100644 (file)
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -43,7 +43,7 @@ static DEFINE_MUTEX(op_arm_mutex);
 
 static struct op_counter_config *counter_config;
 static struct perf_event **perf_events[nr_cpumask_bits];
-static int perf_num_counters;
+static int num_counters;
 
 /*
  * Overflow callback for oprofile.
@@ -54,11 +54,11 @@ static void op_overflow_handler(struct perf_event *event, int unused,
        int id;
        u32 cpu = smp_processor_id();
 
-       for (id = 0; id < perf_num_counters; ++id)
+       for (id = 0; id < num_counters; ++id)
                if (perf_events[cpu][id] == event)
                        break;
 
-       if (id != perf_num_counters)
+       if (id != num_counters)
                oprofile_add_sample(regs, id);
        else
                pr_warning("oprofile: ignoring spurious overflow "
@@ -76,7 +76,7 @@ static void op_perf_setup(void)
        u32 size = sizeof(struct perf_event_attr);
        struct perf_event_attr *attr;
 
-       for (i = 0; i < perf_num_counters; ++i) {
+       for (i = 0; i < num_counters; ++i) {
                attr = &counter_config[i].attr;
                memset(attr, 0, size);
                attr->type              = PERF_TYPE_RAW;
@@ -131,7 +131,7 @@ static int op_perf_start(void)
        int cpu, event, ret = 0;
 
        for_each_online_cpu(cpu) {
-               for (event = 0; event < perf_num_counters; ++event) {
+               for (event = 0; event < num_counters; ++event) {
                        ret = op_create_counter(cpu, event);
                        if (ret)
                                goto out;
@@ -150,7 +150,7 @@ static void op_perf_stop(void)
        int cpu, event;
 
        for_each_online_cpu(cpu)
-               for (event = 0; event < perf_num_counters; ++event)
+               for (event = 0; event < num_counters; ++event)
                        op_destroy_counter(cpu, event);
 }
 
@@ -179,7 +179,7 @@ static int op_arm_create_files(struct super_block *sb, struct dentry *root)
 {
        unsigned int i;
 
-       for (i = 0; i < perf_num_counters; i++) {
+       for (i = 0; i < num_counters; i++) {
                struct dentry *dir;
                char buf[4];
 
@@ -275,7 +275,7 @@ out:
        return ret;
 }
 
-static void  exit_driverfs(void)
+static void __exit exit_driverfs(void)
 {
        platform_device_unregister(oprofile_pdev);
        platform_driver_unregister(&oprofile_driver);
@@ -351,32 +351,37 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
 {
        int cpu, ret = 0;
 
-       perf_num_counters = armpmu_get_max_events();
+       memset(&perf_events, 0, sizeof(perf_events));
 
-       counter_config = kcalloc(perf_num_counters,
+       num_counters = perf_num_counters();
+       if (num_counters <= 0) {
+               pr_info("oprofile: no performance counters\n");
+               ret = -ENODEV;
+               goto out;
+       }
+
+       counter_config = kcalloc(num_counters,
                        sizeof(struct op_counter_config), GFP_KERNEL);
 
        if (!counter_config) {
                pr_info("oprofile: failed to allocate %d "
-                               "counters\n", perf_num_counters);
-               return -ENOMEM;
+                               "counters\n", num_counters);
+               ret = -ENOMEM;
+               goto out;
        }
 
        ret = init_driverfs();
-       if (ret) {
-               kfree(counter_config);
-               return ret;
-       }
+       if (ret)
+               goto out;
 
        for_each_possible_cpu(cpu) {
-               perf_events[cpu] = kcalloc(perf_num_counters,
+               perf_events[cpu] = kcalloc(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;
+                                       "for cpu %d\n", num_counters, cpu);
+                       ret = -ENOMEM;
+                       goto out;
                }
        }
 
@@ -393,28 +398,33 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
        else
                pr_info("oprofile: using %s\n", ops->cpu_type);
 
+out:
+       if (ret) {
+               for_each_possible_cpu(cpu)
+                       kfree(perf_events[cpu]);
+               kfree(counter_config);
+       }
+
        return ret;
 }
 
-void oprofile_arch_exit(void)
+void __exit oprofile_arch_exit(void)
 {
        int cpu, id;
        struct perf_event *event;
 
-       if (*perf_events) {
-               exit_driverfs();
-               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]);
+       for_each_possible_cpu(cpu) {
+               for (id = 0; id < num_counters; ++id) {
+                       event = perf_events[cpu][id];
+                       if (event)
+                               perf_event_release_kernel(event);
                }
+
+               kfree(perf_events[cpu]);
        }
 
-       if (counter_config)
-               kfree(counter_config);
+       kfree(counter_config);
+       exit_driverfs();
 }
 #else
 int __init oprofile_arch_init(struct oprofile_operations *ops)
@@ -422,5 +432,5 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
        pr_info("oprofile: hardware counters not available\n");
        return -ENODEV;
 }
-void oprofile_arch_exit(void) {}
+void __exit oprofile_arch_exit(void) {}
 #endif /* CONFIG_HW_PERF_EVENTS */