drm/i915: Retry execbuffer pinning after clearing the GTT

If we fail to pin all of the buffers in an execbuffer request, go through
and clear the GTT and try again to see if its just a matter of fragmentation

Signed-off-by: Keith Packard <[e-mail]>
Signed-off-by: Eric Anholt <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/i915/i915_gem.c

···
 }
 
 static int
+i915_gem_evict_everything(struct drm_device *dev)
+{
+	int ret;
+
+	for (;;) {
+		ret = i915_gem_evict_something(dev);
+		if (ret != 0)
+			break;
+	}
+	return ret;
+}
+
+static int
 i915_gem_object_get_page_list(struct drm_gem_object *obj)
 {
 	struct drm_i915_gem_object *obj_priv = obj->driver_private;
···
 
 		ret = i915_gem_evict_something(dev);
 		if (ret != 0) {
-			DRM_ERROR("Failed to evict a buffer %d\n", ret);
+			if (ret != -ERESTARTSYS)
+				DRM_ERROR("Failed to evict a buffer %d\n", ret);
 			return ret;
 		}
 		goto search_free;
···
 	int ret, i, pinned = 0;
 	uint64_t exec_offset;
 	uint32_t seqno, flush_domains;
+	int pin_tries;
 
 #if WATCH_EXEC
 	DRM_INFO("buffers_ptr %d buffer_count %d len %08x\n",
···
 		return -EBUSY;
 	}
 
-	/* Look up object handles and perform the relocations */
+	/* Look up object handles */
 	for (i = 0; i < args->buffer_count; i++) {
 		object_list[i] = drm_gem_object_lookup(dev, file_priv,
 						       exec_list[i].handle);
···
 			ret = -EBADF;
 			goto err;
 		}
+	}
 
-		object_list[i]->pending_read_domains = 0;
-		object_list[i]->pending_write_domain = 0;
-		ret = i915_gem_object_pin_and_relocate(object_list[i],
-						       file_priv,
-						       &exec_list[i]);
-		if (ret) {
-			DRM_ERROR("object bind and relocate failed %d\n", ret);
+	/* Pin and relocate */
+	for (pin_tries = 0; ; pin_tries++) {
+		ret = 0;
+		for (i = 0; i < args->buffer_count; i++) {
+			object_list[i]->pending_read_domains = 0;
+			object_list[i]->pending_write_domain = 0;
+			ret = i915_gem_object_pin_and_relocate(object_list[i],
+							       file_priv,
+							       &exec_list[i]);
+			if (ret)
+				break;
+			pinned = i + 1;
+		}
+		/* success */
+		if (ret == 0)
+			break;
+
+		/* error other than GTT full, or we've already tried again */
+		if (ret != -ENOMEM || pin_tries >= 1) {
+			DRM_ERROR("Failed to pin buffers %d\n", ret);
 			goto err;
 		}
-		pinned = i + 1;
+
+		/* unpin all of our buffers */
+		for (i = 0; i < pinned; i++)
+			i915_gem_object_unpin(object_list[i]);
+
+		/* evict everyone we can from the aperture */
+		ret = i915_gem_evict_everything(dev);
+		if (ret)
+			goto err;
 	}
 
 	/* Set the pending read domains for the batch buffer to COMMAND */