drm/amdgpu: add new unlocked flag for PTE updates

For HMM support we need the ability to invalidate PTEs from
a MM callback where we can't lock the root PD.

Add a new flag to better support this instead of assuming
that all invalidation updates are unlocked.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1446,7 +1446,7 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
 		uint64_t incr, entry_end, pe_start;
 		struct amdgpu_bo *pt;
 
-		if (flags & (AMDGPU_PTE_VALID | AMDGPU_PTE_PRT)) {
+		if (!params->unlocked) {
 			/* make sure that the page tables covering the
 			 * address range are actually allocated
 			 */
@@ -1458,8 +1458,12 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
 
 		shift = amdgpu_vm_level_shift(adev, cursor.level);
 		parent_shift = amdgpu_vm_level_shift(adev, cursor.level - 1);
-		if (adev->asic_type < CHIP_VEGA10 &&
-		    (flags & AMDGPU_PTE_VALID)) {
+		if (params->unlocked) {
+			/* Unlocked updates are only allowed on the leaves */
+			if (amdgpu_vm_pt_descendant(adev, &cursor))
+				continue;
+		} else if (adev->asic_type < CHIP_VEGA10 &&
+			   (flags & AMDGPU_PTE_VALID)) {
 			/* No huge page support before GMC v9 */
 			if (cursor.level != AMDGPU_VM_PTB) {
 				if (!amdgpu_vm_pt_descendant(adev, &cursor))
@@ -1558,6 +1562,7 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
  * @adev: amdgpu_device pointer
  * @vm: requested vm
  * @immediate: immediate submission in a page fault
+ * @unlocked: unlocked invalidation during MM callback
  * @resv: fences we need to sync to
  * @start: start of mapped range
  * @last: last mapped entry
@@ -1573,7 +1578,7 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
  */
 static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 				       struct amdgpu_vm *vm, bool immediate,
-				       struct dma_resv *resv,
+				       bool unlocked, struct dma_resv *resv,
 				       uint64_t start, uint64_t last,
 				       uint64_t flags, uint64_t addr,
 				       dma_addr_t *pages_addr,
@@ -1603,11 +1608,12 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 		goto error_unlock;
 	}
 
-	if (flags & (AMDGPU_PTE_VALID | AMDGPU_PTE_PRT)) {
-		struct amdgpu_bo *root = vm->root.base.bo;
+	if (!unlocked && !dma_fence_is_signaled(vm->last_unlocked)) {
+		struct dma_fence *tmp = dma_fence_get_stub();
 
-		if (!dma_fence_is_signaled(vm->last_immediate))
-			amdgpu_bo_fence(root, vm->last_immediate, true);
+		amdgpu_bo_fence(vm->root.base.bo, vm->last_unlocked, true);
+		swap(vm->last_unlocked, tmp);
+		dma_fence_put(tmp);
 	}
 
 	r = vm->update_funcs->prepare(&params, resv, sync_mode);
@@ -1721,7 +1727,7 @@ static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
 		}
 
 		last = min((uint64_t)mapping->last, start + max_entries - 1);
-		r = amdgpu_vm_bo_update_mapping(adev, vm, false, resv,
+		r = amdgpu_vm_bo_update_mapping(adev, vm, false, false, resv,
 						start, last, flags, addr,
 						dma_addr, fence);
 		if (r)
@@ -2018,7 +2024,7 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
 		    mapping->start < AMDGPU_GMC_HOLE_START)
 			init_pte_value = AMDGPU_PTE_DEFAULT_ATC;
 
-		r = amdgpu_vm_bo_update_mapping(adev, vm, false, resv,
+		r = amdgpu_vm_bo_update_mapping(adev, vm, false, false, resv,
 						mapping->start, mapping->last,
 						init_pte_value, 0, NULL, &f);
 		amdgpu_vm_free_mapping(adev, vm, mapping, f);
@@ -2582,7 +2588,7 @@ bool amdgpu_vm_evictable(struct amdgpu_bo *bo)
 		return false;
 
 	/* Don't evict VM page tables while they are updated */
-	if (!dma_fence_is_signaled(bo_base->vm->last_immediate)) {
+	if (!dma_fence_is_signaled(bo_base->vm->last_unlocked)) {
 		amdgpu_vm_eviction_unlock(bo_base->vm);
 		return false;
 	}
@@ -2759,7 +2765,7 @@ long amdgpu_vm_wait_idle(struct amdgpu_vm *vm, long timeout)
 	if (timeout <= 0)
 		return timeout;
 
-	return dma_fence_wait_timeout(vm->last_immediate, true, timeout);
+	return dma_fence_wait_timeout(vm->last_unlocked, true, timeout);
 }
 
 /**
@@ -2831,7 +2837,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 	else
 		vm->update_funcs = &amdgpu_vm_sdma_funcs;
 	vm->last_update = NULL;
-	vm->last_immediate = dma_fence_get_stub();
+	vm->last_unlocked = dma_fence_get_stub();
 
 	mutex_init(&vm->eviction_lock);
 	vm->evicting = false;
@@ -2885,7 +2891,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 	vm->root.base.bo = NULL;
 
 error_free_delayed:
-	dma_fence_put(vm->last_immediate);
+	dma_fence_put(vm->last_unlocked);
 	drm_sched_entity_destroy(&vm->delayed);
 
 error_free_immediate:
@@ -3086,8 +3092,8 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 		vm->pasid = 0;
 	}
 
-	dma_fence_wait(vm->last_immediate, false);
-	dma_fence_put(vm->last_immediate);
+	dma_fence_wait(vm->last_unlocked, false);
+	dma_fence_put(vm->last_unlocked);
 
 	list_for_each_entry_safe(mapping, tmp, &vm->freed, list) {
 		if (mapping->flags & AMDGPU_PTE_PRT && prt_fini_needed) {
@@ -3337,8 +3343,8 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, unsigned int pasid,
 		value = 0;
 	}
 
-	r = amdgpu_vm_bo_update_mapping(adev, vm, true, NULL, addr, addr + 1,
-					flags, value, NULL, NULL);
+	r = amdgpu_vm_bo_update_mapping(adev, vm, true, false, NULL, addr,
+					addr + 1, flags, value, NULL, NULL);
 	if (r)
 		goto error_unlock;
 

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

@@ -210,6 +210,11 @@ struct amdgpu_vm_update_params {
 	 */
 	bool immediate;
 
+	/**
+	 * @unlocked: true if the root BO is not locked
+	 */
+	bool unlocked;
+
 	/**
 	 * @pages_addr:
 	 *
@@ -277,8 +282,8 @@ struct amdgpu_vm {
 	struct drm_sched_entity	immediate;
 	struct drm_sched_entity	delayed;
 
-	/* Last submission to the scheduler entities */
-	struct dma_fence	*last_immediate;
+	/* Last unlocked submission to the scheduler entities */
+	struct dma_fence	*last_unlocked;
 
 	unsigned int		pasid;
 	/* dedicated to vm */

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

@@ -92,8 +92,8 @@ static int amdgpu_vm_sdma_commit(struct amdgpu_vm_update_params *p,
 {
 	struct amdgpu_ib *ib = p->job->ibs;
 	struct drm_sched_entity *entity;
-	struct dma_fence *f, *tmp;
 	struct amdgpu_ring *ring;
+	struct dma_fence *f;
 	int r;
 
 	entity = p->immediate ? &p->vm->immediate : &p->vm->delayed;
@@ -106,13 +106,13 @@ static int amdgpu_vm_sdma_commit(struct amdgpu_vm_update_params *p,
 	if (r)
 		goto error;
 
-	if (p->immediate) {
-		tmp = dma_fence_get(f);
-		swap(p->vm->last_immediate, f);
+	if (p->unlocked) {
+		struct dma_fence *tmp = dma_fence_get(f);
+
+		swap(p->vm->last_unlocked, f);
 		dma_fence_put(tmp);
 	} else {
-		dma_resv_add_shared_fence(p->vm->root.base.bo->tbo.base.resv,
-					  f);
+		amdgpu_bo_fence(p->vm->root.base.bo, f, true);
 	}
 
 	if (fence && !p->immediate)