drm/amdgpu: nuke the VM PD/PT shadow handling

This was only used as workaround for recovering the page tables after
VRAM was lost and is no longer necessary after the function
amdgpu_vm_bo_reset_state_machine() started to do the same.

Compute never used shadows either, so the only proplematic case left is
SVM and that is most likely not recoverable in any way when VRAM is
lost.

Signed-off-by: Christian König <[e-mail]>
Acked-by: Lijo Lazar <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

···
 
 	struct amdgpu_virt	virt;
 
-	/* link all shadow bo */
-	struct list_head                shadow_list;
-	struct mutex                    shadow_list_lock;
-
 	/* record hw reset is performed */
 	bool has_hw_reset;
 	u8				reset_magic[AMDGPU_RESET_MAGIC_NUM];

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

···
 	spin_lock_init(&adev->mm_stats.lock);
 	spin_lock_init(&adev->wb.lock);
 
-	INIT_LIST_HEAD(&adev->shadow_list);
-	mutex_init(&adev->shadow_list_lock);
-
 	INIT_LIST_HEAD(&adev->reset_list);
 
 	INIT_LIST_HEAD(&adev->ras_list);
···
 }
 
 /**
- * amdgpu_device_recover_vram - Recover some VRAM contents
- *
- * @adev: amdgpu_device pointer
- *
- * Restores the contents of VRAM buffers from the shadows in GTT.  Used to
- * restore things like GPUVM page tables after a GPU reset where
- * the contents of VRAM might be lost.
- *
- * Returns:
- * 0 on success, negative error code on failure.
- */
-static int amdgpu_device_recover_vram(struct amdgpu_device *adev)
-{
-	struct dma_fence *fence = NULL, *next = NULL;
-	struct amdgpu_bo *shadow;
-	struct amdgpu_bo_vm *vmbo;
-	long r = 1, tmo;
-
-	if (amdgpu_sriov_runtime(adev))
-		tmo = msecs_to_jiffies(8000);
-	else
-		tmo = msecs_to_jiffies(100);
-
-	dev_info(adev->dev, "recover vram bo from shadow start\n");
-	mutex_lock(&adev->shadow_list_lock);
-	list_for_each_entry(vmbo, &adev->shadow_list, shadow_list) {
-		/* If vm is compute context or adev is APU, shadow will be NULL */
-		if (!vmbo->shadow)
-			continue;
-		shadow = vmbo->shadow;
-
-		/* No need to recover an evicted BO */
-		if (!shadow->tbo.resource ||
-		    shadow->tbo.resource->mem_type != TTM_PL_TT ||
-		    shadow->tbo.resource->start == AMDGPU_BO_INVALID_OFFSET ||
-		    shadow->parent->tbo.resource->mem_type != TTM_PL_VRAM)
-			continue;
-
-		r = amdgpu_bo_restore_shadow(shadow, &next);
-		if (r)
-			break;
-
-		if (fence) {
-			tmo = dma_fence_wait_timeout(fence, false, tmo);
-			dma_fence_put(fence);
-			fence = next;
-			if (tmo == 0) {
-				r = -ETIMEDOUT;
-				break;
-			} else if (tmo < 0) {
-				r = tmo;
-				break;
-			}
-		} else {
-			fence = next;
-		}
-	}
-	mutex_unlock(&adev->shadow_list_lock);
-
-	if (fence)
-		tmo = dma_fence_wait_timeout(fence, false, tmo);
-	dma_fence_put(fence);
-
-	if (r < 0 || tmo <= 0) {
-		dev_err(adev->dev, "recover vram bo from shadow failed, r is %ld, tmo is %ld\n", r, tmo);
-		return -EIO;
-	}
-
-	dev_info(adev->dev, "recover vram bo from shadow done\n");
-	return 0;
-}
-
-
-/**
  * amdgpu_device_reset_sriov - reset ASIC for SR-IOV vf
  *
  * @adev: amdgpu_device pointer
···
 	if (r)
 		return r;
 
-	if (adev->virt.gim_feature & AMDGIM_FEATURE_GIM_FLR_VRAMLOST) {
+	if (adev->virt.gim_feature & AMDGIM_FEATURE_GIM_FLR_VRAMLOST)
 		amdgpu_inc_vram_lost(adev);
-		r = amdgpu_device_recover_vram(adev);
-	}
-	if (r)
-		return r;
 
 	/* need to be called during full access so we can't do it later like
 	 * bare-metal does.
···
 			}
 		}
 
-		if (!r)
-			r = amdgpu_device_recover_vram(tmp_adev);
-		else
+		if (r)
 			tmp_adev->asic_reset_res = r;
 	}
 

drivers/gpu/drm/amd/amdgpu/amdgpu_object.c

···
 	amdgpu_bo_destroy(tbo);
 }
 
-static void amdgpu_bo_vm_destroy(struct ttm_buffer_object *tbo)
-{
-	struct amdgpu_device *adev = amdgpu_ttm_adev(tbo->bdev);
-	struct amdgpu_bo *shadow_bo = ttm_to_amdgpu_bo(tbo), *bo;
-	struct amdgpu_bo_vm *vmbo;
-
-	bo = shadow_bo->parent;
-	vmbo = to_amdgpu_bo_vm(bo);
-	/* in case amdgpu_device_recover_vram got NULL of bo->parent */
-	if (!list_empty(&vmbo->shadow_list)) {
-		mutex_lock(&adev->shadow_list_lock);
-		list_del_init(&vmbo->shadow_list);
-		mutex_unlock(&adev->shadow_list_lock);
-	}
-
-	amdgpu_bo_destroy(tbo);
-}
-
 /**
  * amdgpu_bo_is_amdgpu_bo - check if the buffer object is an &amdgpu_bo
  * @bo: buffer object to be checked
···
 bool amdgpu_bo_is_amdgpu_bo(struct ttm_buffer_object *bo)
 {
 	if (bo->destroy == &amdgpu_bo_destroy ||
-	    bo->destroy == &amdgpu_bo_user_destroy ||
-	    bo->destroy == &amdgpu_bo_vm_destroy)
+	    bo->destroy == &amdgpu_bo_user_destroy)
 		return true;
 
 	return false;
···
 
 	*vmbo_ptr = to_amdgpu_bo_vm(bo_ptr);
 	return r;
-}
-
-/**
- * amdgpu_bo_add_to_shadow_list - add a BO to the shadow list
- *
- * @vmbo: BO that will be inserted into the shadow list
- *
- * Insert a BO to the shadow list.
- */
-void amdgpu_bo_add_to_shadow_list(struct amdgpu_bo_vm *vmbo)
-{
-	struct amdgpu_device *adev = amdgpu_ttm_adev(vmbo->bo.tbo.bdev);
-
-	mutex_lock(&adev->shadow_list_lock);
-	list_add_tail(&vmbo->shadow_list, &adev->shadow_list);
-	vmbo->shadow->parent = amdgpu_bo_ref(&vmbo->bo);
-	vmbo->shadow->tbo.destroy = &amdgpu_bo_vm_destroy;
-	mutex_unlock(&adev->shadow_list_lock);
-}
-
-/**
- * amdgpu_bo_restore_shadow - restore an &amdgpu_bo shadow
- *
- * @shadow: &amdgpu_bo shadow to be restored
- * @fence: dma_fence associated with the operation
- *
- * Copies a buffer object's shadow content back to the object.
- * This is used for recovering a buffer from its shadow in case of a gpu
- * reset where vram context may be lost.
- *
- * Returns:
- * 0 for success or a negative error code on failure.
- */
-int amdgpu_bo_restore_shadow(struct amdgpu_bo *shadow, struct dma_fence **fence)
-
-{
-	struct amdgpu_device *adev = amdgpu_ttm_adev(shadow->tbo.bdev);
-	struct amdgpu_ring *ring = adev->mman.buffer_funcs_ring;
-	uint64_t shadow_addr, parent_addr;
-
-	shadow_addr = amdgpu_bo_gpu_offset(shadow);
-	parent_addr = amdgpu_bo_gpu_offset(shadow->parent);
-
-	return amdgpu_copy_buffer(ring, shadow_addr, parent_addr,
-				  amdgpu_bo_size(shadow), NULL, fence,
-				  true, false, 0);
 }
 
 /**

drivers/gpu/drm/amd/amdgpu/amdgpu_object.h

···
 
 struct amdgpu_bo_vm {
 	struct amdgpu_bo		bo;
-	struct amdgpu_bo		*shadow;
-	struct list_head		shadow_list;
 	struct amdgpu_vm_bo_base        entries[];
 };
 
···
 	return bo->flags & AMDGPU_GEM_CREATE_ENCRYPTED;
 }
 
-/**
- * amdgpu_bo_shadowed - check if the BO is shadowed
- *
- * @bo: BO to be tested.
- *
- * Returns:
- * NULL if not shadowed or else return a BO pointer.
- */
-static inline struct amdgpu_bo *amdgpu_bo_shadowed(struct amdgpu_bo *bo)
-{
-	if (bo->tbo.type == ttm_bo_type_kernel)
-		return to_amdgpu_bo_vm(bo)->shadow;
-
-	return NULL;
-}
-
 bool amdgpu_bo_is_amdgpu_bo(struct ttm_buffer_object *bo);
 void amdgpu_bo_placement_from_domain(struct amdgpu_bo *abo, u32 domain);
 
···
 u64 amdgpu_bo_gpu_offset_no_check(struct amdgpu_bo *bo);
 void amdgpu_bo_get_memory(struct amdgpu_bo *bo,
 			  struct amdgpu_mem_stats *stats);
-void amdgpu_bo_add_to_shadow_list(struct amdgpu_bo_vm *vmbo);
-int amdgpu_bo_restore_shadow(struct amdgpu_bo *shadow,
-			     struct dma_fence **fence);
 uint32_t amdgpu_bo_get_preferred_domain(struct amdgpu_device *adev,
 					    uint32_t domain);
 

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

···
 {
 	uint64_t new_vm_generation = amdgpu_vm_generation(adev, vm);
 	struct amdgpu_vm_bo_base *bo_base;
-	struct amdgpu_bo *shadow;
 	struct amdgpu_bo *bo;
 	int r;
 
···
 		spin_unlock(&vm->status_lock);
 
 		bo = bo_base->bo;
-		shadow = amdgpu_bo_shadowed(bo);
 
 		r = validate(param, bo);
 		if (r)
 			return r;
-		if (shadow) {
-			r = validate(param, shadow);
-			if (r)
-				return r;
-		}
 
 		if (bo->tbo.type != ttm_bo_type_kernel) {
 			amdgpu_vm_bo_moved(bo_base);
···
 {
 	struct amdgpu_vm_bo_base *bo_base;
 
-	/* shadow bo doesn't have bo base, its validation needs its parent */
-	if (bo->parent && (amdgpu_bo_shadowed(bo->parent) == bo))
-		bo = bo->parent;
-
 	for (bo_base = bo->vm_bo; bo_base; bo_base = bo_base->next) {
 		struct amdgpu_vm *vm = bo_base->vm;
 
···
 	root_bo = amdgpu_bo_ref(&root->bo);
 	r = amdgpu_bo_reserve(root_bo, true);
 	if (r) {
-		amdgpu_bo_unref(&root->shadow);
 		amdgpu_bo_unref(&root_bo);
 		goto error_free_delayed;
 	}
···
 	dma_fence_put(vm->last_update);
 	vm->last_update = dma_fence_get_stub();
 	vm->is_compute_context = true;
-
-	/* Free the shadow bo for compute VM */
-	amdgpu_bo_unref(&to_amdgpu_bo_vm(vm->root.bo)->shadow);
-
-	goto unreserve_bo;
 
 unreserve_bo:
 	amdgpu_bo_unreserve(vm->root.bo);

drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c

···
 	if (r)
 		return r;
 
-	if (vmbo->shadow) {
-		struct amdgpu_bo *shadow = vmbo->shadow;
-
-		r = ttm_bo_validate(&shadow->tbo, &shadow->placement, &ctx);
-		if (r)
-			return r;
-	}
-
 	if (!drm_dev_enter(adev_to_drm(adev), &idx))
 		return -ENODEV;
 
···
 			int32_t xcp_id)
 {
 	struct amdgpu_bo_param bp;
-	struct amdgpu_bo *bo;
-	struct dma_resv *resv;
 	unsigned int num_entries;
-	int r;
 
 	memset(&bp, 0, sizeof(bp));
 
···
 	if (vm->root.bo)
 		bp.resv = vm->root.bo->tbo.base.resv;
 
-	r = amdgpu_bo_create_vm(adev, &bp, vmbo);
-	if (r)
-		return r;
-
-	bo = &(*vmbo)->bo;
-	if (vm->is_compute_context || (adev->flags & AMD_IS_APU)) {
-		(*vmbo)->shadow = NULL;
-		return 0;
-	}
-
-	if (!bp.resv)
-		WARN_ON(dma_resv_lock(bo->tbo.base.resv,
-				      NULL));
-	resv = bp.resv;
-	memset(&bp, 0, sizeof(bp));
-	bp.size = amdgpu_vm_pt_size(adev, level);
-	bp.domain = AMDGPU_GEM_DOMAIN_GTT;
-	bp.flags = AMDGPU_GEM_CREATE_CPU_GTT_USWC;
-	bp.type = ttm_bo_type_kernel;
-	bp.resv = bo->tbo.base.resv;
-	bp.bo_ptr_size = sizeof(struct amdgpu_bo);
-	bp.xcp_id_plus1 = xcp_id + 1;
-
-	r = amdgpu_bo_create(adev, &bp, &(*vmbo)->shadow);
-
-	if (!resv)
-		dma_resv_unlock(bo->tbo.base.resv);
-
-	if (r) {
-		amdgpu_bo_unref(&bo);
-		return r;
-	}
-
-	amdgpu_bo_add_to_shadow_list(*vmbo);
-
-	return 0;
+	return amdgpu_bo_create_vm(adev, &bp, vmbo);
 }
 
 /**
···
 	return 0;
 
 error_free_pt:
-	amdgpu_bo_unref(&pt->shadow);
 	amdgpu_bo_unref(&pt_bo);
 	return r;
 }
···
  */
 static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry)
 {
-	struct amdgpu_bo *shadow;
-
 	if (!entry->bo)
 		return;
 
 	entry->bo->vm_bo = NULL;
-	shadow = amdgpu_bo_shadowed(entry->bo);
-	if (shadow) {
-		ttm_bo_set_bulk_move(&shadow->tbo, NULL);
-		amdgpu_bo_unref(&shadow);
-	}
 	ttm_bo_set_bulk_move(&entry->bo->tbo, NULL);
 
 	spin_lock(&entry->vm->status_lock);

drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c

···
  */
 static int amdgpu_vm_sdma_map_table(struct amdgpu_bo_vm *table)
 {
-	int r;
-
-	r = amdgpu_ttm_alloc_gart(&table->bo.tbo);
-	if (r)
-		return r;
-
-	if (table->shadow)
-		r = amdgpu_ttm_alloc_gart(&table->shadow->tbo);
-
-	return r;
+	return amdgpu_ttm_alloc_gart(&table->bo.tbo);
 }
 
 /* Allocate a new job for @count PTE updates */
···
 
 		if (!p->pages_addr) {
 			/* set page commands needed */
-			if (vmbo->shadow)
-				amdgpu_vm_sdma_set_ptes(p, vmbo->shadow, pe, addr,
-							count, incr, flags);
 			amdgpu_vm_sdma_set_ptes(p, bo, pe, addr, count,
 						incr, flags);
 			return 0;
 		}
 
 		/* copy commands needed */
-		ndw -= p->adev->vm_manager.vm_pte_funcs->copy_pte_num_dw *
-			(vmbo->shadow ? 2 : 1);
+		ndw -= p->adev->vm_manager.vm_pte_funcs->copy_pte_num_dw;
 
 		/* for padding */
 		ndw -= 7;
···
 			pte[i] |= flags;
 		}
 
-		if (vmbo->shadow)
-			amdgpu_vm_sdma_copy_ptes(p, vmbo->shadow, pe, nptes);
 		amdgpu_vm_sdma_copy_ptes(p, bo, pe, nptes);
 
 		pe += nptes * 8;