[RFC PATCH v4] drm/amdgpu: Remove kfd eviction fence before release bo

[Pan, Xinhui]

No need to trigger eviction as the memory mapping will not be used anymore.

All pt/pd bos share same resv, hence the same shared eviction fence. Everytime page table is freed, the fence will be signled and that cuases kfd unexcepted evictions.

Signed-off-by: xinhui pan <xinhui.pan at example.com>
---
change from v3:
fix a coding error

change from v2:
based on Chris' drm/ttm: rework BO delayed delete patchset.

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    |  1 +
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 36 +++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c    |  2 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |  1 +
 drivers/gpu/drm/ttm/ttm_bo.c                  | 16 +++++----
 5 files changed, 49 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 47b0f2957d1f..265b1ed7264c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -96,6 +96,7 @@ struct amdgpu_amdkfd_fence *amdgpu_amdkfd_fence_create(u64 context,
 						       struct mm_struct *mm);
 bool amdkfd_fence_check_mm(struct dma_fence *f, struct mm_struct *mm);
 struct amdgpu_amdkfd_fence *to_amdgpu_amdkfd_fence(struct dma_fence *f);
+int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo);
 
 struct amdkfd_process_info {
 	/* List head of all VMs that belong to a KFD process */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index ef721cb65868..d4b117065c1e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -276,6 +276,41 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
 	return 0;
 }
 
+int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo)
+{
+	struct amdgpu_bo *root = bo;
+	struct amdgpu_vm_bo_base *vm_bo;
+	struct amdgpu_vm *vm;
+	struct amdkfd_process_info *info;
+	struct amdgpu_amdkfd_fence *ef;
+	int ret;
+
+	while (root->parent)
+		root = root->parent;
+
+	vm_bo = root->vm_bo;
+	if (!vm_bo)
+		return 0;
+
+	vm = vm_bo->vm;
+	if (!vm)
+		return 0;
+
+	info = vm->process_info;
+	if (!info || !info->eviction_fence)
+		return 0;
+
+	ef = container_of(dma_fence_get(&info->eviction_fence->base),
+			struct amdgpu_amdkfd_fence, base);
+
+	BUG_ON(!dma_resv_trylock(&bo->tbo.base._resv));
+	ret = amdgpu_amdkfd_remove_eviction_fence(bo, ef);
+	dma_resv_unlock(&bo->tbo.base._resv);
+
+	dma_fence_put(&ef->base);
+	return ret;
+}
+
 static int amdgpu_amdkfd_bo_validate(struct amdgpu_bo *bo, uint32_t domain,
 				     bool wait)
 {
@@ -1051,6 +1086,7 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
 		WARN_ON(!list_empty(&process_info->userptr_valid_list));
 		WARN_ON(!list_empty(&process_info->userptr_inval_list));
 
+		vm->process_info = NULL;
 		dma_fence_put(&process_info->eviction_fence->base);
 		cancel_delayed_work_sync(&process_info->restore_userptr_work);
 		put_pid(process_info->pid);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 6f60a581e3ba..3784d178c965 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -1307,6 +1307,8 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo)
 	if (abo->kfd_bo)
 		amdgpu_amdkfd_unreserve_memory_limit(abo);
 
+	amdgpu_amdkfd_remove_fence_on_pt_pd_bos(abo);
+
 	if (bo->mem.mem_type != TTM_PL_VRAM || !bo->mem.mm_node ||
 	    !(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE))
 		return;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 247f328b7223..eca4ec66c1ee 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -3109,6 +3109,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 	}
 
 	amdgpu_vm_free_pts(adev, vm, NULL);
+	root->vm_bo = NULL;
 	amdgpu_bo_unreserve(root);
 	amdgpu_bo_unref(&root);
 	WARN_ON(vm->root.base.bo);
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 6c3cea509e25..855d3566381e 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -399,8 +399,7 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
 	BUG_ON(!dma_resv_trylock(&bo->base._resv));
 
 	r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
-	if (r)
-		dma_resv_unlock(&bo->base._resv);
+	dma_resv_unlock(&bo->base._resv);
 
 	return r;
 }
@@ -565,9 +564,6 @@ static void ttm_bo_release(struct kref *kref)
 	int ret;
 
 	if (!bo->deleted) {
-		if (bo->bdev->driver->release_notify)
-			bo->bdev->driver->release_notify(bo);
-
 		drm_vma_offset_remove(bdev->vma_manager, &bo->base.vma_node);
 		ttm_mem_io_lock(man, false);
 		ttm_mem_io_free_vm(bo);
@@ -581,6 +577,14 @@ static void ttm_bo_release(struct kref *kref)
 			dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
 						  30 * HZ);
 		}
+
+		spin_lock(&ttm_bo_glob.lru_lock);
+		if (bo->type != ttm_bo_type_sg)
+			bo->base.resv = &bo->base._resv;
+		spin_unlock(&ttm_bo_glob.lru_lock);
+
+		if (bo->bdev->driver->release_notify)
+			bo->bdev->driver->release_notify(bo);
 	}
 
 	if (!dma_resv_test_signaled_rcu(bo->base.resv, true)) {
@@ -599,8 +603,6 @@ static void ttm_bo_release(struct kref *kref)
 		}
 
 		spin_lock(&ttm_bo_glob.lru_lock);
-		if (bo->type != ttm_bo_type_sg)
-			bo->base.resv = &bo->base._resv;
 		kref_init(&bo->kref);
 		list_add_tail(&bo->ddestroy, &bdev->ddestroy);
 		spin_unlock(&ttm_bo_glob.lru_lock);
-- 
2.17.1