drm/i915: Mark the context and address space as closed

When the user closes the context mark it and the dependent address space
as closed. As we use an asynchronous destruct method, this has two
purposes.  First it allows us to flag the closed context and detect
internal errors if we to create any new objects for it (as it is removed
from the user's namespace, these should be internal bugs only). And
secondly, it allows us to immediately reap stale vma.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470293567-10811-27-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -907,6 +907,7 @@ struct i915_gem_context {
 	struct list_head link;
 
 	u8 remap_slice;
+	bool closed:1;
 };
 
 enum fb_op_origin {

drivers/gpu/drm/i915/i915_gem.c

@@ -2857,12 +2857,15 @@ static int __i915_vma_unbind(struct i915_vma *vma, bool wait)
 		__i915_vma_iounmap(vma);
 	}
 
+	if (likely(!vma->vm->closed)) {
 		trace_i915_vma_unbind(vma);
-
 		vma->vm->unbind_vma(vma);
+	}
 	vma->bound = 0;
 
-	list_del_init(&vma->vm_link);
+	drm_mm_remove_node(&vma->node);
+	list_move_tail(&vma->vm_link, &vma->vm->unbound_list);
+
 	if (vma->is_ggtt) {
 		if (vma->ggtt_view.type == I915_GGTT_VIEW_NORMAL) {
 			obj->map_and_fenceable = false;
@@ -2873,8 +2876,6 @@ static int __i915_vma_unbind(struct i915_vma *vma, bool wait)
 		vma->ggtt_view.pages = NULL;
 	}
 
-	drm_mm_remove_node(&vma->node);
-
 	/* Since the unbound list is global, only move to that list if
 	 * no more VMAs exist. */
 	if (--obj->bind_count == 0)
@@ -3116,7 +3117,7 @@ i915_gem_object_bind_to_vm(struct drm_i915_gem_object *obj,
 		goto err_remove_node;
 
 	list_move_tail(&obj->global_list, &dev_priv->mm.bound_list);
-	list_add_tail(&vma->vm_link, &vm->inactive_list);
+	list_move_tail(&vma->vm_link, &vm->inactive_list);
 	obj->bind_count++;
 
 	return vma;

drivers/gpu/drm/i915/i915_gem_context.c

@@ -156,6 +156,7 @@ void i915_gem_context_free(struct kref *ctx_ref)
 
 	lockdep_assert_held(&ctx->i915->drm.struct_mutex);
 	trace_i915_context_free(ctx);
+	GEM_BUG_ON(!ctx->closed);
 
 	/*
 	 * This context is going away and we need to remove all VMAs still
@@ -224,6 +225,37 @@ i915_gem_alloc_context_obj(struct drm_device *dev, size_t size)
 	return obj;
 }
 
+static void i915_ppgtt_close(struct i915_address_space *vm)
+{
+	struct list_head *phases[] = {
+		&vm->active_list,
+		&vm->inactive_list,
+		&vm->unbound_list,
+		NULL,
+	}, **phase;
+
+	GEM_BUG_ON(vm->closed);
+	vm->closed = true;
+
+	for (phase = phases; *phase; phase++) {
+		struct i915_vma *vma, *vn;
+
+		list_for_each_entry_safe(vma, vn, *phase, vm_link)
+			if (!vma->closed)
+				i915_vma_close(vma);
+	}
+}
+
+static void context_close(struct i915_gem_context *ctx)
+{
+	GEM_BUG_ON(ctx->closed);
+	ctx->closed = true;
+	if (ctx->ppgtt)
+		i915_ppgtt_close(&ctx->ppgtt->base);
+	ctx->file_priv = ERR_PTR(-EBADF);
+	i915_gem_context_put(ctx);
+}
+
 static int assign_hw_id(struct drm_i915_private *dev_priv, unsigned *out)
 {
 	int ret;
@@ -305,7 +337,7 @@ __create_hw_context(struct drm_device *dev,
 	return ctx;
 
 err_out:
-	i915_gem_context_put(ctx);
+	context_close(ctx);
 	return ERR_PTR(ret);
 }
 
@@ -334,7 +366,7 @@ i915_gem_create_context(struct drm_device *dev,
 			DRM_DEBUG_DRIVER("PPGTT setup failed (%ld)\n",
 					 PTR_ERR(ppgtt));
 			idr_remove(&file_priv->context_idr, ctx->user_handle);
-			i915_gem_context_put(ctx);
+			context_close(ctx);
 			return ERR_CAST(ppgtt);
 		}
 
@@ -505,7 +537,7 @@ void i915_gem_context_fini(struct drm_device *dev)
 
 	lockdep_assert_held(&dev->struct_mutex);
 
-	i915_gem_context_put(dctx);
+	context_close(dctx);
 	dev_priv->kernel_context = NULL;
 
 	ida_destroy(&dev_priv->context_hw_ida);
@@ -515,8 +547,7 @@ static int context_idr_cleanup(int id, void *p, void *data)
 {
 	struct i915_gem_context *ctx = p;
 
-	ctx->file_priv = ERR_PTR(-EBADF);
-	i915_gem_context_put(ctx);
+	context_close(ctx);
 	return 0;
 }
 
@@ -1014,7 +1045,7 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
 	}
 
 	idr_remove(&file_priv->context_idr, ctx->user_handle);
-	i915_gem_context_put(ctx);
+	context_close(ctx);
 	mutex_unlock(&dev->struct_mutex);
 
 	DRM_DEBUG_DRIVER("HW context %d destroyed\n", args->ctx_id);

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -2121,6 +2121,7 @@ static void i915_address_space_init(struct i915_address_space *vm,
 	drm_mm_init(&vm->mm, vm->start, vm->total);
 	INIT_LIST_HEAD(&vm->active_list);
 	INIT_LIST_HEAD(&vm->inactive_list);
+	INIT_LIST_HEAD(&vm->unbound_list);
 	list_add_tail(&vm->global_link, &dev_priv->vm_list);
 }
 
@@ -2213,9 +2214,10 @@ void  i915_ppgtt_release(struct kref *kref)
 
 	trace_i915_ppgtt_release(&ppgtt->base);
 
-	/* vmas should already be unbound */
+	/* vmas should already be unbound and destroyed */
 	WARN_ON(!list_empty(&ppgtt->base.active_list));
 	WARN_ON(!list_empty(&ppgtt->base.inactive_list));
+	WARN_ON(!list_empty(&ppgtt->base.unbound_list));
 
 	list_del(&ppgtt->base.global_link);
 	drm_mm_takedown(&ppgtt->base.mm);
@@ -3377,6 +3379,8 @@ __i915_gem_vma_create(struct drm_i915_gem_object *obj,
 	struct i915_vma *vma;
 	int i;
 
+	GEM_BUG_ON(vm->closed);
+
 	if (WARN_ON(i915_is_ggtt(vm) != !!ggtt_view))
 		return ERR_PTR(-EINVAL);
 
@@ -3384,11 +3388,11 @@ __i915_gem_vma_create(struct drm_i915_gem_object *obj,
 	if (vma == NULL)
 		return ERR_PTR(-ENOMEM);
 
-	INIT_LIST_HEAD(&vma->vm_link);
 	INIT_LIST_HEAD(&vma->obj_link);
 	INIT_LIST_HEAD(&vma->exec_list);
 	for (i = 0; i < ARRAY_SIZE(vma->last_read); i++)
 		init_request_active(&vma->last_read[i], i915_vma_retire);
+	list_add(&vma->vm_link, &vm->unbound_list);
 	vma->vm = vm;
 	vma->obj = obj;
 	vma->is_ggtt = i915_is_ggtt(vm);
@@ -3429,6 +3433,7 @@ i915_gem_obj_lookup_or_create_ggtt_vma(struct drm_i915_gem_object *obj,
 	if (!vma)
 		vma = __i915_gem_vma_create(obj, &ggtt->base, view);
 
+	GEM_BUG_ON(vma->closed);
 	return vma;
 
 }

drivers/gpu/drm/i915/i915_gem_gtt.h

@@ -319,6 +319,8 @@ struct i915_address_space {
 	u64 start;		/* Start offset always 0 for dri2 */
 	u64 total;		/* size addr space maps (ex. 2GB for ggtt) */
 
+	bool closed;
+
 	struct i915_page_scratch *scratch_page;
 	struct i915_page_table *scratch_pt;
 	struct i915_page_directory *scratch_pd;
@@ -347,6 +349,13 @@ struct i915_address_space {
 	 */
 	struct list_head inactive_list;
 
+	/**
+	 * List of vma that have been unbound.
+	 *
+	 * A reference is not held on the buffer while on this list.
+	 */
+	struct list_head unbound_list;
+
 	/* FIXME: Need a more generic return type */
 	gen6_pte_t (*pte_encode)(dma_addr_t addr,
 				 enum i915_cache_level level,

drivers/gpu/drm/i915/i915_gem_stolen.c

@@ -707,7 +707,7 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 
 	vma->bound |= GLOBAL_BIND;
 	__i915_vma_set_map_and_fenceable(vma);
-	list_add_tail(&vma->vm_link, &ggtt->base.inactive_list);
+	list_move_tail(&vma->vm_link, &ggtt->base.inactive_list);
 	obj->bind_count++;
 
 	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);