diff options
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index 03c1e5e3580c..5fe29e4972d8 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -2461,6 +2461,27 @@ static int amdgpu_ttm_prepare_job(struct amdgpu_device *adev, DMA_RESV_USAGE_BOOKKEEP); } +static int amdgpu_calc_bytes_per_packet(u32 max_bytes_per_packet, + u32 byte_count) +{ + /* Byte count is dword-aligned and fits a single packet */ + if (!(byte_count & 0x3) && byte_count <= max_bytes_per_packet) + return max_bytes_per_packet; + + /* + * Align down maximum byte count to 256 bytes so that + * the copy optimally uses all memory channels and + * also to ensure that SDMA can use its dword mode, which + * is faster. + * + * This assumes that the starting addresses of BOs are always + * dword aligned, which should be the case for every copy + * operation in the kernel, because the kernel always copies + * pages. + */ + return ALIGN_DOWN(max_bytes_per_packet, SZ_256); +} + int amdgpu_copy_buffer(struct amdgpu_device *adev, struct amdgpu_ttm_buffer_entity *entity, uint64_t src_offset, @@ -2484,7 +2505,8 @@ int amdgpu_copy_buffer(struct amdgpu_device *adev, return -EINVAL; } - max_bytes = adev->mman.buffer_funcs->copy_max_bytes; + max_bytes = amdgpu_calc_bytes_per_packet(adev->mman.buffer_funcs->copy_max_bytes, + byte_count); num_loops = DIV_ROUND_UP(byte_count, max_bytes); num_dw = ALIGN(num_loops * adev->mman.buffer_funcs->copy_num_dw, 8); r = amdgpu_ttm_prepare_job(adev, entity, num_dw, @@ -2528,7 +2550,8 @@ static int amdgpu_ttm_fill_mem(struct amdgpu_device *adev, unsigned int i; int r; - max_bytes = adev->mman.buffer_funcs->fill_max_bytes; + max_bytes = amdgpu_calc_bytes_per_packet(adev->mman.buffer_funcs->fill_max_bytes, + byte_count); num_loops = DIV_ROUND_UP_ULL(byte_count, max_bytes); num_dw = ALIGN(num_loops * adev->mman.buffer_funcs->fill_num_dw, 8); r = amdgpu_ttm_prepare_job(adev, entity, num_dw, resv, |