On 10/28/25 23:06, Timur Kristóf wrote:
> Binds a BO that is allocated in VRAM to the GART page table.
>
> Useful when a kernel BO is located in VRAM but
> needs to be accessed from the GART address space,
> for example to give a kernel BO a 32-bit address
> when GART is placed in LOW address space.
>
> Co-developed-by: Christian König <[email protected]>
> Signed-off-by: Christian König <[email protected]>
> Signed-off-by: Timur Kristóf <[email protected]>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c | 41 ++++++++++++++++++++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h | 2 ++
> 2 files changed, 43 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> index 83f3b94ed975..19b5e72a6a26 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
> @@ -390,6 +390,47 @@ void amdgpu_gart_bind(struct amdgpu_device *adev,
> uint64_t offset,
> amdgpu_gart_map(adev, offset, pages, dma_addr, flags, adev->gart.ptr);
> }
>
> +/**
> + * amdgpu_gart_bind - bind VRAM BO into the GART page table
That should be the function name or otherwise you get automated warnings.
> + *
> + * @adev: amdgpu_device pointer
> + * @offset: offset into the GPU's gart aperture
> + * @bo: the BO whose pages should be mapped
> + * @flags: page table entry flags
> + *
> + * Binds a BO that is allocated in VRAM to the GART page table
> + * (all ASICs).
> + * Useful when a kernel BO is located in VRAM but
> + * needs to be accessed from the GART address space,
> + * for example to give a kernel BO a 32-bit address
> + * when GART is placed in LOW address space.
> + */
> +void amdgpu_gart_bind_vram_bo(struct amdgpu_device *adev, uint64_t offset,
> + struct amdgpu_bo *bo, uint64_t flags)
Please not the BO but just the VRAM pa.
> +{
> + u64 pa, bo_size;
> + u32 num_pages, start_page, i, idx;
> +
> + if (!adev->gart.ptr)
> + return;
> +
> + if (!drm_dev_enter(adev_to_drm(adev), &idx))
> + return;
> +
> + pa = amdgpu_gmc_vram_pa(adev, bo);
> + bo_size = amdgpu_bo_size(bo);
> + num_pages = ALIGN(bo_size, AMDGPU_GPU_PAGE_SIZE) / AMDGPU_GPU_PAGE_SIZE;
> + start_page = offset / AMDGPU_GPU_PAGE_SIZE;
> +
> + for (i = 0; i < num_pages; ++i) {
> + amdgpu_gmc_set_pte_pde(adev, adev->gart.ptr,
> + start_page + i, pa + AMDGPU_GPU_PAGE_SIZE * i, flags);
> + }
> +
Ideally amdgpu_gart_map() should be able to take both dma_addr array or VRAM pa
(or have two map functions).
This way we could cleanup the code in amdgpu_ttm_map_buffer as well.
> + amdgpu_gart_invalidate_tlb(adev);
IIRC we moved that out of amdgpu_gart_bind(), probably best to do so here as
well.
Regards,
Christian.
> + drm_dev_exit(idx);
> +}
> +
> /**
> * amdgpu_gart_invalidate_tlb - invalidate gart TLB
> *
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h
> index 7cc980bf4725..756548d0b520 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.h
> @@ -64,5 +64,7 @@ void amdgpu_gart_map(struct amdgpu_device *adev, uint64_t
> offset,
> void *dst);
> void amdgpu_gart_bind(struct amdgpu_device *adev, uint64_t offset,
> int pages, dma_addr_t *dma_addr, uint64_t flags);
> +void amdgpu_gart_bind_vram_bo(struct amdgpu_device *adev, uint64_t offset,
> + struct amdgpu_bo *bo, uint64_t flags);
> void amdgpu_gart_invalidate_tlb(struct amdgpu_device *adev);
> #endif
