[PATCH 1/4] drm/amdgpu: optimize amdgpu_device_vram_access a bit.
Christian König
ckoenig.leichtzumerken at gmail.com
Thu Feb 6 14:30:48 UTC 2020
Only write the _HI register when necessary.
Signed-off-by: Christian König <christian.koenig at amd.com>
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
Acked-by: Jonathan Kim <Jonathan.Kim at amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index f33c49ed4f94..be4e6c33d7e3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -184,20 +184,25 @@ bool amdgpu_device_supports_baco(struct drm_device *dev)
void amdgpu_device_vram_access(struct amdgpu_device *adev, loff_t pos,
uint32_t *buf, size_t size, bool write)
{
- uint64_t last;
unsigned long flags;
+ uint32_t hi = ~0;
+ uint64_t last;
+
+ spin_lock_irqsave(&adev->mmio_idx_lock, flags);
+ for (last = pos + size; pos < last; pos += 4) {
+ uint32_t tmp = pos >> 31;
- last = size - 4;
- for (last += pos; pos <= last; pos += 4) {
- spin_lock_irqsave(&adev->mmio_idx_lock, flags);
WREG32_NO_KIQ(mmMM_INDEX, ((uint32_t)pos) | 0x80000000);
- WREG32_NO_KIQ(mmMM_INDEX_HI, pos >> 31);
+ if (tmp != hi) {
+ WREG32_NO_KIQ(mmMM_INDEX_HI, tmp);
+ hi = tmp;
+ }
if (write)
WREG32_NO_KIQ(mmMM_DATA, *buf++);
else
*buf++ = RREG32_NO_KIQ(mmMM_DATA);
- spin_unlock_irqrestore(&adev->mmio_idx_lock, flags);
}
+ spin_unlock_irqrestore(&adev->mmio_idx_lock, flags);
}
/*
--
2.17.1
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