The ARMv8 Performance Monitors Extension includes an architectural
event type named CHAIN which allows for chaining counters together.
Let's extract the test for this event into a header file such that
other users, such as KVM (for PMU emulation) can make use of.
Signed-off-by: Andrew Murray <andrew.murray at arm.com>
---
arch/arm64/include/asm/perf_event.h | 5 +++++
arch/arm64/kernel/perf_event.c | 2 +-
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/perf_event.h b/arch/arm64/include/asm/perf_event.h
index c593761..cd13f3f 100644
--- a/arch/arm64/include/asm/perf_event.h
+++ b/arch/arm64/include/asm/perf_event.h
@@ -219,6 +219,11 @@
#define ARMV8_PMU_USERENR_CR (1 << 2) /* Cycle counter can be read at EL0 */
#define ARMV8_PMU_USERENR_ER (1 << 3) /* Event counter can be read at EL0 */
+static inline bool armv8pmu_evtype_is_chain(u64 evtype)
+{
+ return (evtype == ARMV8_PMUV3_PERFCTR_CHAIN);
+}
+
#ifdef CONFIG_PERF_EVENTS
struct pt_regs;
extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 1620a37..4cd1f7a 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -850,7 +850,7 @@ static int armv8pmu_set_event_filter(struct hw_perf_event *event,
static int armv8pmu_filter_match(struct perf_event *event)
{
unsigned long evtype = event->hw.config_base & ARMV8_PMU_EVTYPE_EVENT;
- return evtype != ARMV8_PMUV3_PERFCTR_CHAIN;
+ return !armv8pmu_evtype_is_chain(evtype);
}
static void armv8pmu_reset(void *info)
--
2.7.4
