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-rw-r--r--drivers/perf/fsl_imx8_ddr_perf.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/perf/fsl_imx8_ddr_perf.c b/drivers/perf/fsl_imx8_ddr_perf.c
index 1cb3861ab0e0..7d4e49565738 100644
--- a/drivers/perf/fsl_imx8_ddr_perf.c
+++ b/drivers/perf/fsl_imx8_ddr_perf.c
@@ -27,6 +27,8 @@
#define CNTL_CLEAR_MASK 0xFFFFFFFD
#define CNTL_OVER_MASK 0xFFFFFFFE
+#define CNTL_CP_SHIFT 16
+#define CNTL_CP_MASK (0xFF << CNTL_CP_SHIFT)
#define CNTL_CSV_SHIFT 24
#define CNTL_CSV_MASK (0xFFU << CNTL_CSV_SHIFT)
@@ -34,6 +36,8 @@
#define EVENT_CYCLES_COUNTER 0
#define NUM_COUNTERS 4
+/* For removing bias if cycle counter CNTL.CP is set to 0xf0 */
+#define CYCLES_COUNTER_MASK 0x0FFFFFFF
#define AXI_MASKING_REVERT 0xffff0000 /* AXI_MASKING(MSB 16bits) + AXI_ID(LSB 16bits) */
#define to_ddr_pmu(p) container_of(p, struct ddr_pmu, pmu)
@@ -426,6 +430,17 @@ static void ddr_perf_counter_enable(struct ddr_pmu *pmu, int config,
writel(0, pmu->base + reg);
val = CNTL_EN | CNTL_CLEAR;
val |= FIELD_PREP(CNTL_CSV_MASK, config);
+
+ /*
+ * On i.MX8MP we need to bias the cycle counter to overflow more often.
+ * We do this by initializing bits [23:16] of the counter value via the
+ * COUNTER_CTRL Counter Parameter (CP) field.
+ */
+ if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER_ENHANCED) {
+ if (counter == EVENT_CYCLES_COUNTER)
+ val |= FIELD_PREP(CNTL_CP_MASK, 0xf0);
+ }
+
writel(val, pmu->base + reg);
} else {
/* Disable counter */
@@ -465,6 +480,12 @@ static void ddr_perf_event_update(struct perf_event *event)
int ret;
new_raw_count = ddr_perf_read_counter(pmu, counter);
+ /* Remove the bias applied in ddr_perf_counter_enable(). */
+ if (pmu->devtype_data->quirks & DDR_CAP_AXI_ID_FILTER_ENHANCED) {
+ if (counter == EVENT_CYCLES_COUNTER)
+ new_raw_count &= CYCLES_COUNTER_MASK;
+ }
+
local64_add(new_raw_count, &event->count);
/*