Am 01.07.21 um 11:57 schrieb YuBiao Wang:
[Why]
GPU timing counters are read via KIQ under sriov, which will introduce
a delay.
[How]
It could be directly read by MMIO.
v2: Add additional check to prevent carryover issue.
v3: Only check for carryover for once to prevent performance issue.
v4: Add comments of the rough frequency where carryover happens.
v5: Remove mutex and gfxoff ctrl unused with current timing registers.
Signed-off-by: YuBiao Wang <YuBiao.Wang@xxxxxxx>
Acked-by: Horace Chen <horace.chen@xxxxxxx>
The preemption_disable()/_enable() would still be nice to have I think.
Anyway patch is Reviewed-by: Christian König <christian.koenig@xxxxxxx>
either way.
Regards,
Christian.
---
drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
index ff7e9f49040e..5f4eae9c9526 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
@@ -7609,10 +7609,8 @@ static int gfx_v10_0_soft_reset(void *handle)
static uint64_t gfx_v10_0_get_gpu_clock_counter(struct amdgpu_device *adev)
{
- uint64_t clock;
+ uint64_t clock, clock_lo, clock_hi, hi_check;
- amdgpu_gfx_off_ctrl(adev, false);
- mutex_lock(&adev->gfx.gpu_clock_mutex);
switch (adev->asic_type) {
case CHIP_VANGOGH:
case CHIP_YELLOW_CARP:
@@ -7620,12 +7618,19 @@ static uint64_t gfx_v10_0_get_gpu_clock_counter(struct amdgpu_device *adev)
((uint64_t)RREG32_SOC15(SMUIO, 0, mmGOLDEN_TSC_COUNT_UPPER_Vangogh) << 32ULL);
break;
default:
- clock = (uint64_t)RREG32_SOC15(SMUIO, 0, mmGOLDEN_TSC_COUNT_LOWER) |
- ((uint64_t)RREG32_SOC15(SMUIO, 0, mmGOLDEN_TSC_COUNT_UPPER) << 32ULL);
+ clock_hi = RREG32_SOC15_NO_KIQ(SMUIO, 0, mmGOLDEN_TSC_COUNT_UPPER);
+ clock_lo = RREG32_SOC15_NO_KIQ(SMUIO, 0, mmGOLDEN_TSC_COUNT_LOWER);
+ hi_check = RREG32_SOC15_NO_KIQ(SMUIO, 0, mmGOLDEN_TSC_COUNT_UPPER);
+ /* The GFX clock frequency is 100MHz, which sets 32-bit carry over
+ * roughly every 42 seconds.
+ */
+ if (hi_check != clock_hi) {
+ clock_lo = RREG32_SOC15_NO_KIQ(SMUIO, 0, mmGOLDEN_TSC_COUNT_LOWER);
+ clock_hi = hi_check;
+ }
+ clock = (uint64_t)clock_lo | ((uint64_t)clock_hi << 32ULL);
break;
}
- mutex_unlock(&adev->gfx.gpu_clock_mutex);
- amdgpu_gfx_off_ctrl(adev, true);
return clock;
}
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