4 files changed, 19 insertions, 20 deletions

diff --git a/drivers/perf/arm-ccn.c b/drivers/perf/arm-ccn.c
index fea354d6fb29..d50edef91f59 100644
--- a/drivers/perf/arm-ccn.c
+++ b/drivers/perf/arm-ccn.c
@@ -328,15 +328,15 @@ static ssize_t arm_ccn_pmu_event_show(struct device *dev,
 			struct arm_ccn_pmu_event, attr);
 	ssize_t res;
 
-	res = snprintf(buf, PAGE_SIZE, "type=0x%x", event->type);
+	res = scnprintf(buf, PAGE_SIZE, "type=0x%x", event->type);
 	if (event->event)
-		res += snprintf(buf + res, PAGE_SIZE - res, ",event=0x%x",
+		res += scnprintf(buf + res, PAGE_SIZE - res, ",event=0x%x",
 				event->event);
 	if (event->def)
-		res += snprintf(buf + res, PAGE_SIZE - res, ",%s",
+		res += scnprintf(buf + res, PAGE_SIZE - res, ",%s",
 				event->def);
 	if (event->mask)
-		res += snprintf(buf + res, PAGE_SIZE - res, ",mask=0x%x",
+		res += scnprintf(buf + res, PAGE_SIZE - res, ",mask=0x%x",
 				event->mask);
 
 	/* Arguments required by an event */
@@ -344,25 +344,25 @@ static ssize_t arm_ccn_pmu_event_show(struct device *dev,
 	case CCN_TYPE_CYCLES:
 		break;
 	case CCN_TYPE_XP:
-		res += snprintf(buf + res, PAGE_SIZE - res,
+		res += scnprintf(buf + res, PAGE_SIZE - res,
 				",xp=?,vc=?");
 		if (event->event == CCN_EVENT_WATCHPOINT)
-			res += snprintf(buf + res, PAGE_SIZE - res,
+			res += scnprintf(buf + res, PAGE_SIZE - res,
 					",port=?,dir=?,cmp_l=?,cmp_h=?,mask=?");
 		else
-			res += snprintf(buf + res, PAGE_SIZE - res,
+			res += scnprintf(buf + res, PAGE_SIZE - res,
 					",bus=?");
 
 		break;
 	case CCN_TYPE_MN:
-		res += snprintf(buf + res, PAGE_SIZE - res, ",node=%d", ccn->mn_id);
+		res += scnprintf(buf + res, PAGE_SIZE - res, ",node=%d", ccn->mn_id);
 		break;
 	default:
-		res += snprintf(buf + res, PAGE_SIZE - res, ",node=?");
+		res += scnprintf(buf + res, PAGE_SIZE - res, ",node=?");
 		break;
 	}
 
-	res += snprintf(buf + res, PAGE_SIZE - res, "\n");
+	res += scnprintf(buf + res, PAGE_SIZE - res, "\n");
 
 	return res;
 }
diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index acce8781c456..f5c7a845cd7b 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -24,8 +24,6 @@ static int arm_pmu_acpi_register_irq(int cpu)
 	int gsi, trigger;
 
 	gicc = acpi_cpu_get_madt_gicc(cpu);
-	if (WARN_ON(!gicc))
-		return -EINVAL;
 
 	gsi = gicc->performance_interrupt;
 
@@ -64,11 +62,10 @@ static void arm_pmu_acpi_unregister_irq(int cpu)
 	int gsi;
 
 	gicc = acpi_cpu_get_madt_gicc(cpu);
-	if (!gicc)
-		return;
 
 	gsi = gicc->performance_interrupt;
-	acpi_unregister_gsi(gsi);
+	if (gsi)
+		acpi_unregister_gsi(gsi);
 }
 
 #if IS_ENABLED(CONFIG_ARM_SPE_PMU)
diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index 4e4984a55cd1..b72c04852599 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -831,7 +831,7 @@ static void *arm_spe_pmu_setup_aux(struct perf_event *event, void **pages,
 	 * parts and give userspace a fighting chance of getting some
 	 * useful data out of it.
 	 */
-	if (!nr_pages || (snapshot && (nr_pages & 1)))
+	if (snapshot && (nr_pages & 1))
 		return NULL;
 
 	if (cpu == -1)
diff --git a/drivers/perf/fsl_imx8_ddr_perf.c b/drivers/perf/fsl_imx8_ddr_perf.c
index 95dca2cb5265..90884d14f95f 100644
--- a/drivers/perf/fsl_imx8_ddr_perf.c
+++ b/drivers/perf/fsl_imx8_ddr_perf.c
@@ -388,9 +388,10 @@ static void ddr_perf_counter_enable(struct ddr_pmu *pmu, int config,
 
 	if (enable) {
 		/*
-		 * must disable first, then enable again
-		 * otherwise, cycle counter will not work
-		 * if previous state is enabled.
+		 * cycle counter is special which should firstly write 0 then
+		 * write 1 into CLEAR bit to clear it. Other counters only
+		 * need write 0 into CLEAR bit and it turns out to be 1 by
+		 * hardware. Below enable flow is harmless for all counters.
 		 */
 		writel(0, pmu->base + reg);
 		val = CNTL_EN | CNTL_CLEAR;
@@ -398,7 +399,8 @@ static void ddr_perf_counter_enable(struct ddr_pmu *pmu, int config,
 		writel(val, pmu->base + reg);
 	} else {
 		/* Disable counter */
-		writel(0, pmu->base + reg);
+		val = readl_relaxed(pmu->base + reg) & CNTL_EN_MASK;
+		writel(val, pmu->base + reg);
 	}
 }