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path: root/drivers/perf/arm_smmuv3_pmu.c
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Diffstat (limited to 'drivers/perf/arm_smmuv3_pmu.c')
-rw-r--r--drivers/perf/arm_smmuv3_pmu.c48
1 files changed, 41 insertions, 7 deletions
diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
index a4f4b488a2de..da71c741cb46 100644
--- a/drivers/perf/arm_smmuv3_pmu.c
+++ b/drivers/perf/arm_smmuv3_pmu.c
@@ -35,6 +35,7 @@
*/
#include <linux/acpi.h>
+#include <linux/acpi_iort.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/cpuhotplug.h>
@@ -93,6 +94,8 @@
#define SMMU_PMCG_PA_SHIFT 12
+#define SMMU_PMCG_EVCNTR_RDONLY BIT(0)
+
static int cpuhp_state_num;
struct smmu_pmu {
@@ -108,6 +111,7 @@ struct smmu_pmu {
void __iomem *reg_base;
void __iomem *reloc_base;
u64 counter_mask;
+ u32 options;
bool global_filter;
u32 global_filter_span;
u32 global_filter_sid;
@@ -222,15 +226,27 @@ static void smmu_pmu_set_period(struct smmu_pmu *smmu_pmu,
u32 idx = hwc->idx;
u64 new;
- /*
- * We limit the max period to half the max counter value of the counter
- * size, so that even in the case of extreme interrupt latency the
- * counter will (hopefully) not wrap past its initial value.
- */
- new = smmu_pmu->counter_mask >> 1;
+ if (smmu_pmu->options & SMMU_PMCG_EVCNTR_RDONLY) {
+ /*
+ * On platforms that require this quirk, if the counter starts
+ * at < half_counter value and wraps, the current logic of
+ * handling the overflow may not work. It is expected that,
+ * those platforms will have full 64 counter bits implemented
+ * so that such a possibility is remote(eg: HiSilicon HIP08).
+ */
+ new = smmu_pmu_counter_get_value(smmu_pmu, idx);
+ } else {
+ /*
+ * We limit the max period to half the max counter value
+ * of the counter size, so that even in the case of extreme
+ * interrupt latency the counter will (hopefully) not wrap
+ * past its initial value.
+ */
+ new = smmu_pmu->counter_mask >> 1;
+ smmu_pmu_counter_set_value(smmu_pmu, idx, new);
+ }
local64_set(&hwc->prev_count, new);
- smmu_pmu_counter_set_value(smmu_pmu, idx, new);
}
static void smmu_pmu_set_event_filter(struct perf_event *event,
@@ -665,6 +681,22 @@ static void smmu_pmu_reset(struct smmu_pmu *smmu_pmu)
smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);
}
+static void smmu_pmu_get_acpi_options(struct smmu_pmu *smmu_pmu)
+{
+ u32 model;
+
+ model = *(u32 *)dev_get_platdata(smmu_pmu->dev);
+
+ switch (model) {
+ case IORT_SMMU_V3_PMCG_HISI_HIP08:
+ /* HiSilicon Erratum 162001800 */
+ smmu_pmu->options |= SMMU_PMCG_EVCNTR_RDONLY;
+ break;
+ }
+
+ dev_notice(smmu_pmu->dev, "option mask 0x%x\n", smmu_pmu->options);
+}
+
static int smmu_pmu_probe(struct platform_device *pdev)
{
struct smmu_pmu *smmu_pmu;
@@ -744,6 +776,8 @@ static int smmu_pmu_probe(struct platform_device *pdev)
return -EINVAL;
}
+ smmu_pmu_get_acpi_options(smmu_pmu);
+
/* Pick one CPU to be the preferred one to use */
smmu_pmu->on_cpu = raw_smp_processor_id();
WARN_ON(irq_set_affinity_hint(smmu_pmu->irq,