Re: [PATCH v6 1/4] perf: arm_cspmu: Split 64-bit write to 32-bit writes

On 15/08/2023 21:46, Ilkka Koskinen wrote:

Hi Suzuki,

On Tue, 15 Aug 2023, Suzuki K Poulose wrote:

quoted

On 15/08/2023 07:35, Ilkka Koskinen wrote:

quoted

Split the 64-bit register accesses if 64-bit access is not supported
by the PMU.

Signed-off-by: Ilkka Koskinen <redacted>
Reviewed-by: Besar Wicaksono <redacted>

Do we need a Fixes tag ?

I believe, NVIDIA's PMU supports 64-bit access while Ampere's one 
doesn't and since this patchset enables support for the latter one, it 
doesn't seem like we need a Fixes tag here.

Ok, makes sense.

Suzuki

Cheers, Ilkka

quoted

With that:

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Suzuki

quoted

---
  drivers/perf/arm_cspmu/arm_cspmu.c | 5 ++++-
  1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c 

b/drivers/perf/arm_cspmu/arm_cspmu.c
index 04be94b4aa48..6387cbad7a7d 100644

--- a/drivers/perf/arm_cspmu/arm_cspmu.c
+++ b/drivers/perf/arm_cspmu/arm_cspmu.c

@@ -715,7 +715,10 @@ static void arm_cspmu_write_counter(struct 

perf_event *event, u64 val)
      if (use_64b_counter_reg(cspmu)) {
          offset = counter_offset(sizeof(u64), event->hw.idx);
  -        writeq(val, cspmu->base1 + offset);
+        if (cspmu->has_atomic_dword)
+            writeq(val, cspmu->base1 + offset);
+        else
+            lo_hi_writeq(val, cspmu->base1 + offset);

quoted

      } else {
          offset = counter_offset(sizeof(u32), event->hw.idx);