drm/i915/cmdparser: Use explicit goto for error paths

In the next patch we will be adding a second valid
termination condition which will require a small
amount of refactoring to share logic with the BB_END
case.

Refactor all error conditions to jump to a dedicated
exit path, with 'break' reserved only for a successful
parse.

Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>

1 files changed, 13 insertions, 12 deletions

diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 6794034c8ced..dc5bcbc3ba6e 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -1338,21 +1338,15 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine,
         do {
                 u32 length;
 
-                if (*cmd == MI_BATCH_BUFFER_END) {
-                        if (needs_clflush_after) {
-                                void *ptr = page_mask_bits(shadow_batch_obj->mm.mapping);
-                                drm_clflush_virt_range(ptr,
-                                                       (void *)(cmd + 1) - ptr);
-                        }
+                if (*cmd == MI_BATCH_BUFFER_END)
                         break;
-                }
 
                 desc = find_cmd(engine, *cmd, desc, &default_desc);
                 if (!desc) {
                         DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n",
                                          *cmd);
                         ret = -EINVAL;
-                        break;
+                        goto err;
                 }
 
                 /*
@@ -1362,7 +1356,7 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine,
                  */
                 if (desc->cmd.value == MI_BATCH_BUFFER_START) {
                         ret = -EACCES;
-                        break;
+                        goto err;
                 }
 
                 if (desc->flags & CMD_DESC_FIXED)
@@ -1376,22 +1370,29 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine,
                                          length,
                                          batch_end - cmd);
                         ret = -EINVAL;
-                        break;
+                        goto err;
                 }
 
                 if (!check_cmd(engine, desc, cmd, length)) {
                         ret = -EACCES;
-                        break;
+                        goto err;
                 }
 
                 cmd += length;
                 if  (cmd >= batch_end) {
                         DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
                         ret = -EINVAL;
-                        break;
+                        goto err;
                 }
         } while (1);
 
+        if (needs_clflush_after) {
+                void *ptr = page_mask_bits(shadow_batch_obj->mm.mapping);
+
+                drm_clflush_virt_range(ptr, (void *)(cmd + 1) - ptr);
+        }
+
+err:
         i915_gem_object_unpin_map(shadow_batch_obj);
         return ret;
 }