drm/i915: Propagate error from drm_gem_object_init()

Propagate the real error from drm_gem_object_init(). Note this also
fixes some confusion in the error return from i915_gem_alloc_object...

v2:
(Matthew Auld)
  - updated new users of gem_alloc_object from latest drm-nightly
  - replaced occurrences of IS_ERR_OR_NULL() with IS_ERR()
v3:
(Joonas Lahtinen)
  - fix double "From:" in commit message
  - add goto teardown path
v4:
(Matthew Auld)
  - rebase with i915_gem_alloc_object name change

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
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/1461587533-8841-1-git-send-email-matthew.auld@intel.com
[Joonas: Removed spurious " = NULL" from _init() function]
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/i915_gem.c

@@ -382,8 +382,8 @@ i915_gem_create(struct drm_file *file,
 
 	/* Allocate the new object */
 	obj = i915_gem_object_create(dev, size);
-	if (obj == NULL)
-		return -ENOMEM;
+	if (IS_ERR(obj))
+		return PTR_ERR(obj);
 
 	ret = drm_gem_handle_create(file, &obj->base, &handle);
 	/* drop reference from allocate - handle holds it now */
@@ -4501,15 +4501,15 @@ struct drm_i915_gem_object *i915_gem_object_create(struct drm_device *dev,
 	struct drm_i915_gem_object *obj;
 	struct address_space *mapping;
 	gfp_t mask;
+	int ret;
 
 	obj = i915_gem_object_alloc(dev);
 	if (obj == NULL)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
-	if (drm_gem_object_init(dev, &obj->base, size) != 0) {
-		i915_gem_object_free(obj);
-		return NULL;
-	}
+	ret = drm_gem_object_init(dev, &obj->base, size);
+	if (ret)
+		goto fail;
 
 	mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
 	if (IS_CRESTLINE(dev) || IS_BROADWATER(dev)) {
@@ -4546,6 +4546,11 @@ struct drm_i915_gem_object *i915_gem_object_create(struct drm_device *dev,
 	trace_i915_gem_object_create(obj);
 
 	return obj;
+
+fail:
+	i915_gem_object_free(obj);
+
+	return ERR_PTR(ret);
 }
 
 static bool discard_backing_storage(struct drm_i915_gem_object *obj)
@@ -5351,7 +5356,7 @@ i915_gem_object_create_from_data(struct drm_device *dev,
 	int ret;
 
 	obj = i915_gem_object_create(dev, round_up(size, PAGE_SIZE));
-	if (IS_ERR_OR_NULL(obj))
+	if (IS_ERR(obj))
 		return obj;
 
 	ret = i915_gem_object_set_to_cpu_domain(obj, true);

drivers/gpu/drm/i915/i915_gem_batch_pool.c

@@ -135,8 +135,8 @@ i915_gem_batch_pool_get(struct i915_gem_batch_pool *pool,
 		int ret;
 
 		obj = i915_gem_object_create(pool->dev, size);
-		if (obj == NULL)
-			return ERR_PTR(-ENOMEM);
+		if (IS_ERR(obj))
+			return obj;
 
 		ret = i915_gem_object_get_pages(obj);
 		if (ret)

drivers/gpu/drm/i915/i915_gem_context.c

@@ -179,8 +179,8 @@ i915_gem_alloc_context_obj(struct drm_device *dev, size_t size)
 	int ret;
 
 	obj = i915_gem_object_create(dev, size);
-	if (obj == NULL)
-		return ERR_PTR(-ENOMEM);
+	if (IS_ERR(obj))
+		return obj;
 
 	/*
 	 * Try to make the context utilize L3 as well as LLC.

drivers/gpu/drm/i915/i915_gem_render_state.c

@@ -58,8 +58,8 @@ static int render_state_init(struct render_state *so, struct drm_device *dev)
 		return -EINVAL;
 
 	so->obj = i915_gem_object_create(dev, 4096);
-	if (so->obj == NULL)
-		return -ENOMEM;
+	if (IS_ERR(so->obj))
+		return PTR_ERR(so->obj);
 
 	ret = i915_gem_obj_ggtt_pin(so->obj, 4096, 0);
 	if (ret)

drivers/gpu/drm/i915/i915_guc_submission.c

@@ -588,7 +588,7 @@ static struct drm_i915_gem_object *gem_allocate_guc_obj(struct drm_device *dev,
 	struct drm_i915_gem_object *obj;
 
 	obj = i915_gem_object_create(dev, size);
-	if (!obj)
+	if (IS_ERR(obj))
 		return NULL;
 
 	if (i915_gem_object_get_pages(obj)) {

drivers/gpu/drm/i915/intel_display.c

@@ -10321,8 +10321,8 @@ intel_framebuffer_create_for_mode(struct drm_device *dev,
 
 	obj = i915_gem_object_create(dev,
 				    intel_framebuffer_size_for_mode(mode, bpp));
-	if (obj == NULL)
-		return ERR_PTR(-ENOMEM);
+	if (IS_ERR(obj))
+		return ERR_CAST(obj);
 
 	mode_cmd.width = mode->hdisplay;
 	mode_cmd.height = mode->vdisplay;

drivers/gpu/drm/i915/intel_fbdev.c

@@ -151,9 +151,9 @@ static int intelfb_alloc(struct drm_fb_helper *helper,
 		obj = i915_gem_object_create_stolen(dev, size);
 	if (obj == NULL)
 		obj = i915_gem_object_create(dev, size);
-	if (!obj) {
+	if (IS_ERR(obj)) {
 		DRM_ERROR("failed to allocate framebuffer\n");
-		ret = -ENOMEM;
+		ret = PTR_ERR(obj);
 		goto out;
 	}
 

drivers/gpu/drm/i915/intel_lrc.c

@@ -1474,9 +1474,11 @@ static int lrc_setup_wa_ctx_obj(struct intel_engine_cs *engine, u32 size)
 
 	engine->wa_ctx.obj = i915_gem_object_create(engine->dev,
 						   PAGE_ALIGN(size));
-	if (!engine->wa_ctx.obj) {
+	if (IS_ERR(engine->wa_ctx.obj)) {
 		DRM_DEBUG_DRIVER("alloc LRC WA ctx backing obj failed.\n");
-		return -ENOMEM;
+		ret = PTR_ERR(engine->wa_ctx.obj);
+		engine->wa_ctx.obj = NULL;
+		return ret;
 	}
 
 	ret = i915_gem_obj_ggtt_pin(engine->wa_ctx.obj, PAGE_SIZE, 0);
@@ -2666,9 +2668,9 @@ int intel_lr_context_deferred_alloc(struct intel_context *ctx,
 	context_size += PAGE_SIZE * LRC_PPHWSP_PN;
 
 	ctx_obj = i915_gem_object_create(dev, context_size);
-	if (!ctx_obj) {
+	if (IS_ERR(ctx_obj)) {
 		DRM_DEBUG_DRIVER("Alloc LRC backing obj failed.\n");
-		return -ENOMEM;
+		return PTR_ERR(ctx_obj);
 	}
 
 	ringbuf = intel_engine_create_ringbuffer(engine, 4 * PAGE_SIZE);

drivers/gpu/drm/i915/intel_overlay.c

@@ -1397,7 +1397,7 @@ void intel_setup_overlay(struct drm_device *dev)
 		reg_bo = i915_gem_object_create_stolen(dev, PAGE_SIZE);
 	if (reg_bo == NULL)
 		reg_bo = i915_gem_object_create(dev, PAGE_SIZE);
-	if (reg_bo == NULL)
+	if (IS_ERR(reg_bo))
 		goto out_free;
 	overlay->reg_bo = reg_bo;
 

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -672,9 +672,10 @@ intel_init_pipe_control(struct intel_engine_cs *engine)
 	WARN_ON(engine->scratch.obj);
 
 	engine->scratch.obj = i915_gem_object_create(engine->dev, 4096);
-	if (engine->scratch.obj == NULL) {
+	if (IS_ERR(engine->scratch.obj)) {
 		DRM_ERROR("Failed to allocate seqno page\n");
-		ret = -ENOMEM;
+		ret = PTR_ERR(engine->scratch.obj);
+		engine->scratch.obj = NULL;
 		goto err;
 	}
 
@@ -2033,9 +2034,9 @@ static int init_status_page(struct intel_engine_cs *engine)
 		int ret;
 
 		obj = i915_gem_object_create(engine->dev, 4096);
-		if (obj == NULL) {
+		if (IS_ERR(obj)) {
 			DRM_ERROR("Failed to allocate status page\n");
-			return -ENOMEM;
+			return PTR_ERR(obj);
 		}
 
 		ret = i915_gem_object_set_cache_level(obj, I915_CACHE_LLC);
@@ -2174,8 +2175,8 @@ static int intel_alloc_ringbuffer_obj(struct drm_device *dev,
 		obj = i915_gem_object_create_stolen(dev, ringbuf->size);
 	if (obj == NULL)
 		obj = i915_gem_object_create(dev, ringbuf->size);
-	if (obj == NULL)
-		return -ENOMEM;
+	if (IS_ERR(obj))
+		return PTR_ERR(obj);
 
 	/* mark ring buffers as read-only from GPU side by default */
 	obj->gt_ro = 1;
@@ -2787,7 +2788,7 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
 	if (INTEL_INFO(dev)->gen >= 8) {
 		if (i915_semaphore_is_enabled(dev)) {
 			obj = i915_gem_object_create(dev, 4096);
-			if (obj == NULL) {
+			if (IS_ERR(obj)) {
 				DRM_ERROR("Failed to allocate semaphore bo. Disabling semaphores\n");
 				i915.semaphores = 0;
 			} else {
@@ -2896,9 +2897,9 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
 	/* Workaround batchbuffer to combat CS tlb bug. */
 	if (HAS_BROKEN_CS_TLB(dev)) {
 		obj = i915_gem_object_create(dev, I830_WA_SIZE);
-		if (obj == NULL) {
+		if (IS_ERR(obj)) {
 			DRM_ERROR("Failed to allocate batch bo\n");
-			return -ENOMEM;
+			return PTR_ERR(obj);
 		}
 
 		ret = i915_gem_obj_ggtt_pin(obj, 0, 0);