On 06/06/2018 05:48 PM, Mark Rutland wrote:
On Tue, May 29, 2018 at 11:55:54AM +0100, Suzuki K Poulose wrote:
Each PMU has a set of 32bit event counters. But in some
special cases, the events could be counted using counters
which are effectively 64bit wide.
e.g, Arm V8 PMUv3 has a 64 bit cycle counter which can count
only the CPU cycles. Also, the PMU can chain the event counters
to effectively count as a 64bit counter.
Add support for tracking the events that uses 64bit counters.
This only affects the periods set for each counter in the core
driver.
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Will Deacon <will.dea...@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
---
Changes since v1:
- Rename ARMPMU_EVT_LONG => ARMPMU_EVT_64BIT
---
drivers/perf/arm_pmu.c | 14 ++++++++------
include/linux/perf/arm_pmu.h | 6 ++++++
2 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 8962d26..ff858e6 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -28,9 +28,10 @@
static DEFINE_PER_CPU(struct arm_pmu *, cpu_armpmu);
static DEFINE_PER_CPU(int, cpu_irq);
-static inline u64 arm_pmu_max_period(void)
+static inline u64 arm_pmu_event_max_period(struct perf_event *event)
{
- return (1ULL << 32) - 1;
+ return (event->hw.flags & ARMPMU_EVT_64BIT) ?
+ ~0ULL : (1ULL << 32) - 1;
}
Could we please have:
static inline u64 arm_pmu_event_max_period(struct perf_event *event)
{
if (event->hw.flags & ARMPMU_EVT_64BIT)
return GENMASK_ULL(63, 0);
else
return GENMASK_ULL(31, 0);
}
... since that's obviously balanced, with both values generated in the
same way.
Sure, will do
Suzuki
