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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
commitd635711daa98be86d4c7fd01499c34f566b54ccb (patch)
treeaa5cc3760a27c3d57146498cb82fa549547de06c /drivers/perf
parentc91265cd0efb83778f015b4d4b1129bd2cfd075e (diff)
Linux-libre 4.6.2-gnu
Diffstat (limited to 'drivers/perf')
-rw-r--r--drivers/perf/arm_pmu.c120
1 files changed, 118 insertions, 2 deletions
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 166637f29..f70090897 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -13,6 +13,7 @@
#include <linux/bitmap.h>
#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/of_device.h>
@@ -710,6 +711,104 @@ static int cpu_pmu_notify(struct notifier_block *b, unsigned long action,
return NOTIFY_OK;
}
+#ifdef CONFIG_CPU_PM
+static void cpu_pm_pmu_setup(struct arm_pmu *armpmu, unsigned long cmd)
+{
+ struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events);
+ struct perf_event *event;
+ int idx;
+
+ for (idx = 0; idx < armpmu->num_events; idx++) {
+ /*
+ * If the counter is not used skip it, there is no
+ * need of stopping/restarting it.
+ */
+ if (!test_bit(idx, hw_events->used_mask))
+ continue;
+
+ event = hw_events->events[idx];
+
+ switch (cmd) {
+ case CPU_PM_ENTER:
+ /*
+ * Stop and update the counter
+ */
+ armpmu_stop(event, PERF_EF_UPDATE);
+ break;
+ case CPU_PM_EXIT:
+ case CPU_PM_ENTER_FAILED:
+ /*
+ * Restore and enable the counter.
+ * armpmu_start() indirectly calls
+ *
+ * perf_event_update_userpage()
+ *
+ * that requires RCU read locking to be functional,
+ * wrap the call within RCU_NONIDLE to make the
+ * RCU subsystem aware this cpu is not idle from
+ * an RCU perspective for the armpmu_start() call
+ * duration.
+ */
+ RCU_NONIDLE(armpmu_start(event, PERF_EF_RELOAD));
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+static int cpu_pm_pmu_notify(struct notifier_block *b, unsigned long cmd,
+ void *v)
+{
+ struct arm_pmu *armpmu = container_of(b, struct arm_pmu, cpu_pm_nb);
+ struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events);
+ int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events);
+
+ if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus))
+ return NOTIFY_DONE;
+
+ /*
+ * Always reset the PMU registers on power-up even if
+ * there are no events running.
+ */
+ if (cmd == CPU_PM_EXIT && armpmu->reset)
+ armpmu->reset(armpmu);
+
+ if (!enabled)
+ return NOTIFY_OK;
+
+ switch (cmd) {
+ case CPU_PM_ENTER:
+ armpmu->stop(armpmu);
+ cpu_pm_pmu_setup(armpmu, cmd);
+ break;
+ case CPU_PM_EXIT:
+ cpu_pm_pmu_setup(armpmu, cmd);
+ case CPU_PM_ENTER_FAILED:
+ armpmu->start(armpmu);
+ break;
+ default:
+ return NOTIFY_DONE;
+ }
+
+ return NOTIFY_OK;
+}
+
+static int cpu_pm_pmu_register(struct arm_pmu *cpu_pmu)
+{
+ cpu_pmu->cpu_pm_nb.notifier_call = cpu_pm_pmu_notify;
+ return cpu_pm_register_notifier(&cpu_pmu->cpu_pm_nb);
+}
+
+static void cpu_pm_pmu_unregister(struct arm_pmu *cpu_pmu)
+{
+ cpu_pm_unregister_notifier(&cpu_pmu->cpu_pm_nb);
+}
+#else
+static inline int cpu_pm_pmu_register(struct arm_pmu *cpu_pmu) { return 0; }
+static inline void cpu_pm_pmu_unregister(struct arm_pmu *cpu_pmu) { }
+#endif
+
static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
{
int err;
@@ -725,6 +824,10 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
if (err)
goto out_hw_events;
+ err = cpu_pm_pmu_register(cpu_pmu);
+ if (err)
+ goto out_unregister;
+
for_each_possible_cpu(cpu) {
struct pmu_hw_events *events = per_cpu_ptr(cpu_hw_events, cpu);
raw_spin_lock_init(&events->pmu_lock);
@@ -746,6 +849,8 @@ static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
return 0;
+out_unregister:
+ unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
out_hw_events:
free_percpu(cpu_hw_events);
return err;
@@ -753,6 +858,7 @@ out_hw_events:
static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
{
+ cpu_pm_pmu_unregister(cpu_pmu);
unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
free_percpu(cpu_pmu->hw_events);
}
@@ -889,6 +995,15 @@ int arm_pmu_device_probe(struct platform_device *pdev,
if (node && (of_id = of_match_node(of_table, pdev->dev.of_node))) {
init_fn = of_id->data;
+ pmu->secure_access = of_property_read_bool(pdev->dev.of_node,
+ "secure-reg-access");
+
+ /* arm64 systems boot only as non-secure */
+ if (IS_ENABLED(CONFIG_ARM64) && pmu->secure_access) {
+ pr_warn("ignoring \"secure-reg-access\" property for arm64\n");
+ pmu->secure_access = false;
+ }
+
ret = of_pmu_irq_cfg(pmu);
if (!ret)
ret = init_fn(pmu);
@@ -898,7 +1013,7 @@ int arm_pmu_device_probe(struct platform_device *pdev,
}
if (ret) {
- pr_info("failed to probe PMU!\n");
+ pr_info("%s: failed to probe PMU!\n", of_node_full_name(node));
goto out_free;
}
@@ -918,7 +1033,8 @@ int arm_pmu_device_probe(struct platform_device *pdev,
out_destroy:
cpu_pmu_destroy(pmu);
out_free:
- pr_info("failed to register PMU devices!\n");
+ pr_info("%s: failed to register PMU devices!\n",
+ of_node_full_name(node));
kfree(pmu);
return ret;
}