drm/amdgpu: Keep a bo-reference per-attachment

For now they all reference the same BO. For correct DMA mappings they will
refer to different BOs per-GPU.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Oak Zeng <Oak.Zeng@amd.com>
Acked-by: Ramesh Errabolu <Ramesh.Errabolu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 7008edd..ee42d56 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -491,11 +491,11 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
                struct amdgpu_vm *vm, bool is_aql,
                struct kfd_mem_attachment **p_attachment)
 {
-       int ret;
-       struct kfd_mem_attachment *attachment;
-       struct amdgpu_bo *bo = mem->bo;
+       unsigned long bo_size = mem->bo->tbo.base.size;
        uint64_t va = mem->va;
-       unsigned long bo_size = bo->tbo.base.size;
+       struct kfd_mem_attachment *attachment;
+       struct amdgpu_bo *bo;
+       int ret;
 
        if (!va) {
                pr_err("Invalid VA when adding BO to VM\n");
@@ -512,6 +512,14 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
        pr_debug("\t add VA 0x%llx - 0x%llx to vm %p\n", va,
                        va + bo_size, vm);
 
+       /* FIXME: For now all attachments use the same BO. This is incorrect
+        * because one BO can only have one DMA mapping for one GPU. We need
+        * one BO per GPU, e.g. a DMABuf import with dynamic attachment. This
+        * will be addressed one BO-type at a time in subsequent patches.
+        */
+       bo = mem->bo;
+       drm_gem_object_get(&bo->tbo.base);
+
        /* Add BO to VM internal data structures*/
        attachment->bo_va = amdgpu_vm_bo_add(adev, vm, bo);
        if (!attachment->bo_va) {
@@ -531,7 +539,7 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
 
        /* Allocate validate page tables if needed */
        ret = vm_validate_pt_pd_bos(vm);
-       if (ret) {
+       if (unlikely(ret)) {
                pr_err("validate_pt_pd_bos() failed\n");
                goto err_alloc_pts;
        }
@@ -542,15 +550,19 @@ err_alloc_pts:
        amdgpu_vm_bo_rmv(adev, attachment->bo_va);
        list_del(&attachment->list);
 err_vmadd:
+       drm_gem_object_put(&bo->tbo.base);
        kfree(attachment);
        return ret;
 }
 
 static void kfd_mem_detach(struct kfd_mem_attachment *attachment)
 {
+       struct amdgpu_bo *bo = attachment->bo_va->base.bo;
+
        pr_debug("\t remove VA 0x%llx in entry %p\n",
                        attachment->va, attachment);
        amdgpu_vm_bo_rmv(attachment->adev, attachment->bo_va);
+       drm_gem_object_put(&bo->tbo.base);
        list_del(&attachment->list);
        kfree(attachment);
 }