1 files changed, 41 insertions, 1 deletions

diff --git a/drivers/perf/hisilicon/hisi_uncore_uc_pmu.c b/drivers/perf/hisilicon/hisi_uncore_uc_pmu.c
index 636fb79647c8..481dcc9e8fbf 100644
--- a/drivers/perf/hisilicon/hisi_uncore_uc_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_uc_pmu.c
@@ -287,12 +287,52 @@ static u64 hisi_uc_pmu_read_counter(struct hisi_pmu *uc_pmu,
 	return readq(uc_pmu->base + HISI_UC_CNTR_REGn(hwc->idx));
 }
 
-static void hisi_uc_pmu_write_counter(struct hisi_pmu *uc_pmu,
+static bool hisi_uc_pmu_get_glb_en_state(struct hisi_pmu *uc_pmu)
+{
+	u32 val;
+
+	val = readl(uc_pmu->base + HISI_UC_EVENT_CTRL_REG);
+	return !!FIELD_GET(HISI_UC_EVENT_GLB_EN, val);
+}
+
+static void hisi_uc_pmu_write_counter_normal(struct hisi_pmu *uc_pmu,
 				      struct hw_perf_event *hwc, u64 val)
 {
 	writeq(val, uc_pmu->base + HISI_UC_CNTR_REGn(hwc->idx));
 }
 
+static void hisi_uc_pmu_write_counter_quirk_v2(struct hisi_pmu *uc_pmu,
+				      struct hw_perf_event *hwc, u64 val)
+{
+	hisi_uc_pmu_start_counters(uc_pmu);
+	hisi_uc_pmu_write_counter_normal(uc_pmu, hwc, val);
+	hisi_uc_pmu_stop_counters(uc_pmu);
+}
+
+static void hisi_uc_pmu_write_counter(struct hisi_pmu *uc_pmu,
+				      struct hw_perf_event *hwc, u64 val)
+{
+	bool enable = hisi_uc_pmu_get_glb_en_state(uc_pmu);
+	bool erratum = uc_pmu->identifier == HISI_PMU_V2;
+
+	/*
+	 * HiSilicon UC PMU v2 suffers the erratum 162700402 that the
+	 * PMU counter cannot be set due to the lack of clock under power
+	 * saving mode. This will lead to error or inaccurate counts.
+	 * The clock can be enabled by the PMU global enabling control.
+	 * The irq handler and pmu_start() will call the function to set
+	 * period. If the function under irq context, the PMU has been
+	 * enabled therefore we set counter directly. Other situations
+	 * the PMU is disabled, we need to enable it to turn on the
+	 * counter clock to set period, and then restore PMU enable
+	 * status, the counter can hold its value without a clock.
+	 */
+	if (enable || !erratum)
+		hisi_uc_pmu_write_counter_normal(uc_pmu, hwc, val);
+	else
+		hisi_uc_pmu_write_counter_quirk_v2(uc_pmu, hwc, val);
+}
+
 static void hisi_uc_pmu_enable_counter_int(struct hisi_pmu *uc_pmu,
 					   struct hw_perf_event *hwc)
 {