+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;
+ }
+}