1 files changed, 101 insertions, 5 deletions

diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index dca3537a8dcc..79a3de515ece 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -17,10 +17,30 @@
 #include <linux/irqdomain.h>
 #include <linux/of_irq.h>
 #include <linux/of.h>
+#include <linux/cpu_pm.h>
 
 #include <asm/sbi.h>
 #include <asm/hwcap.h>
 
+PMU_FORMAT_ATTR(event, "config:0-47");
+PMU_FORMAT_ATTR(firmware, "config:63");
+
+static struct attribute *riscv_arch_formats_attr[] = {
+	&format_attr_event.attr,
+	&format_attr_firmware.attr,
+	NULL,
+};
+
+static struct attribute_group riscv_pmu_format_group = {
+	.name = "format",
+	.attrs = riscv_arch_formats_attr,
+};
+
+static const struct attribute_group *riscv_pmu_attr_groups[] = {
+	&riscv_pmu_format_group,
+	NULL,
+};
+
 union sbi_pmu_ctr_info {
 	unsigned long value;
 	struct {
@@ -666,12 +686,15 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
 		child = of_get_compatible_child(cpu, "riscv,cpu-intc");
 		if (!child) {
 			pr_err("Failed to find INTC node\n");
+			of_node_put(cpu);
 			return -ENODEV;
 		}
 		domain = irq_find_host(child);
 		of_node_put(child);
-		if (domain)
+		if (domain) {
+			of_node_put(cpu);
 			break;
+		}
 	}
 	if (!domain) {
 		pr_err("Failed to find INTC IRQ root domain\n");
@@ -693,6 +716,73 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
 	return 0;
 }
 
+#ifdef CONFIG_CPU_PM
+static int riscv_pm_pmu_notify(struct notifier_block *b, unsigned long cmd,
+				void *v)
+{
+	struct riscv_pmu *rvpmu = container_of(b, struct riscv_pmu, riscv_pm_nb);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(rvpmu->hw_events);
+	int enabled = bitmap_weight(cpuc->used_hw_ctrs, RISCV_MAX_COUNTERS);
+	struct perf_event *event;
+	int idx;
+
+	if (!enabled)
+		return NOTIFY_OK;
+
+	for (idx = 0; idx < RISCV_MAX_COUNTERS; idx++) {
+		event = cpuc->events[idx];
+		if (!event)
+			continue;
+
+		switch (cmd) {
+		case CPU_PM_ENTER:
+			/*
+			 * Stop and update the counter
+			 */
+			riscv_pmu_stop(event, PERF_EF_UPDATE);
+			break;
+		case CPU_PM_EXIT:
+		case CPU_PM_ENTER_FAILED:
+			/*
+			 * Restore and enable the counter.
+			 *
+			 * 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 riscv_pmu_start() call
+			 * duration.
+			 */
+			RCU_NONIDLE(riscv_pmu_start(event, PERF_EF_RELOAD));
+			break;
+		default:
+			break;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static int riscv_pm_pmu_register(struct riscv_pmu *pmu)
+{
+	pmu->riscv_pm_nb.notifier_call = riscv_pm_pmu_notify;
+	return cpu_pm_register_notifier(&pmu->riscv_pm_nb);
+}
+
+static void riscv_pm_pmu_unregister(struct riscv_pmu *pmu)
+{
+	cpu_pm_unregister_notifier(&pmu->riscv_pm_nb);
+}
+#else
+static inline int riscv_pm_pmu_register(struct riscv_pmu *pmu) { return 0; }
+static inline void riscv_pm_pmu_unregister(struct riscv_pmu *pmu) { }
+#endif
+
+static void riscv_pmu_destroy(struct riscv_pmu *pmu)
+{
+	riscv_pm_pmu_unregister(pmu);
+	cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
+}
+
 static int pmu_sbi_device_probe(struct platform_device *pdev)
 {
 	struct riscv_pmu *pmu = NULL;
@@ -720,6 +810,7 @@ static int pmu_sbi_device_probe(struct platform_device *pdev)
 		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
 		pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;
 	}
+	pmu->pmu.attr_groups = riscv_pmu_attr_groups;
 	pmu->num_counters = num_counters;
 	pmu->ctr_start = pmu_sbi_ctr_start;
 	pmu->ctr_stop = pmu_sbi_ctr_stop;
@@ -733,14 +824,19 @@ static int pmu_sbi_device_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = riscv_pm_pmu_register(pmu);
+	if (ret)
+		goto out_unregister;
+
 	ret = perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW);
-	if (ret) {
-		cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARTING, &pmu->node);
-		return ret;
-	}
+	if (ret)
+		goto out_unregister;
 
 	return 0;
 
+out_unregister:
+	riscv_pmu_destroy(pmu);
+
 out_free:
 	kfree(pmu);
 	return ret;