Use DMABufs with dynamic attachment to DMA-map GTT BOs on other GPUs.
Signed-off-by: Felix Kuehling Felix.Kuehling@amd.com --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 2 + .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 74 ++++++++++++++++++- 2 files changed, 75 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h index fc3514ed1b74..3ea51982b720 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h @@ -41,6 +41,7 @@ struct amdgpu_device; enum kfd_mem_attachment_type { KFD_MEM_ATT_SHARED, /* Share kgd_mem->bo or another attachment's */ KFD_MEM_ATT_USERPTR, /* SG bo to DMA map pages from a userptr bo */ + KFD_MEM_ATT_DMABUF, /* DMAbuf to DMA map TTM BOs */ };
struct kfd_mem_attachment { @@ -56,6 +57,7 @@ struct kfd_mem_attachment { struct kgd_mem { struct mutex lock; struct amdgpu_bo *bo; + struct dma_buf *dmabuf; struct list_head attachments; /* protected by amdkfd_process_info.lock */ struct ttm_validate_buffer validate_list; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index 1416f3c03f1d..bb3a96ab8f20 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -522,6 +522,16 @@ kfd_mem_dmamap_userptr(struct kgd_mem *mem, return ret; }
+static int +kfd_mem_dmamap_dmabuf(struct kfd_mem_attachment *attachment) +{ + struct ttm_operation_ctx ctx = {.interruptible = true}; + struct amdgpu_bo *bo = attachment->bo_va->base.bo; + + amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT); + return ttm_bo_validate(&bo->tbo, &bo->placement, &ctx); +} + static int kfd_mem_dmamap_attachment(struct kgd_mem *mem, struct kfd_mem_attachment *attachment) @@ -531,6 +541,8 @@ kfd_mem_dmamap_attachment(struct kgd_mem *mem, return 0; case KFD_MEM_ATT_USERPTR: return kfd_mem_dmamap_userptr(mem, attachment); + case KFD_MEM_ATT_DMABUF: + return kfd_mem_dmamap_dmabuf(attachment); default: WARN_ON_ONCE(1); } @@ -560,6 +572,19 @@ kfd_mem_dmaunmap_userptr(struct kgd_mem *mem, ttm->sg = NULL; }
+static void +kfd_mem_dmaunmap_dmabuf(struct kfd_mem_attachment *attachment) +{ + struct ttm_operation_ctx ctx = {.interruptible = true}; + struct amdgpu_bo *bo = attachment->bo_va->base.bo; + + amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU); + ttm_bo_validate(&bo->tbo, &bo->placement, &ctx); + /* FIXME: This does not guarantee that amdgpu_ttm_tt_unpopulate is + * called + */ +} + static void kfd_mem_dmaunmap_attachment(struct kgd_mem *mem, struct kfd_mem_attachment *attachment) @@ -570,6 +595,9 @@ kfd_mem_dmaunmap_attachment(struct kgd_mem *mem, case KFD_MEM_ATT_USERPTR: kfd_mem_dmaunmap_userptr(mem, attachment); break; + case KFD_MEM_ATT_DMABUF: + kfd_mem_dmaunmap_dmabuf(attachment); + break; default: WARN_ON_ONCE(1); } @@ -601,6 +629,36 @@ kfd_mem_attach_userptr(struct amdgpu_device *adev, struct kgd_mem *mem, return 0; }
+static int +kfd_mem_attach_dmabuf(struct amdgpu_device *adev, struct kgd_mem *mem, + struct amdgpu_bo **bo) +{ + struct drm_gem_object *gobj; + + if (!mem->dmabuf) { + mem->dmabuf = amdgpu_gem_prime_export(&mem->bo->tbo.base, + mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ? + DRM_RDWR : 0); + if (IS_ERR(mem->dmabuf)) { + mem->dmabuf = NULL; + return PTR_ERR(mem->dmabuf); + } + } + + gobj = amdgpu_gem_prime_import(&adev->ddev, mem->dmabuf); + if (IS_ERR(gobj)) + return PTR_ERR(gobj); + + /* Import takes an extra reference on the dmabuf. Drop it now to + * avoid leaking it. We only need the one reference in + * kgd_mem->dmabuf. + */ + dma_buf_put(mem->dmabuf); + + *bo = gem_to_amdgpu_bo(gobj); + return 0; +} + /* kfd_mem_attach - Add a BO to a VM * * Everything that needs to bo done only once when a BO is first added @@ -658,8 +716,20 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem, ret = kfd_mem_attach_userptr(adev, mem, &bo[i]); if (ret) goto unwind; + } else if (mem->domain == AMDGPU_GEM_DOMAIN_GTT && + mem->bo->tbo.type != ttm_bo_type_sg) { + /* GTT BOs use DMA-mapping ability of dynamic-attach + * DMA bufs. TODO: The same should work for VRAM on + * large-BAR GPUs. + */ + attachment[i]->type = KFD_MEM_ATT_DMABUF; + ret = kfd_mem_attach_dmabuf(adev, mem, &bo[i]); + if (ret) + goto unwind; } else { - /* FIXME: Need to DMA-map other BO types */ + /* FIXME: Need to DMA-map other BO types: + * large-BAR VRAM, doorbells, MMIO remap + */ attachment[i]->type = KFD_MEM_ATT_SHARED; bo[i] = mem->bo; drm_gem_object_get(&bo[i]->tbo.base); @@ -1558,6 +1628,8 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu( }
/* Free the BO*/ + if (mem->dmabuf) + dma_buf_put(mem->dmabuf); drm_gem_object_put(&mem->bo->tbo.base); mutex_destroy(&mem->lock); kfree(mem);