drm/i915: Add a fault injection point to WOPCM init

Add a fault injection point in the WOPCM initialization path.

v4:
Move the injection inside the WOPCM init function.

Signed-off-by: Jakub Bartmiński <jakub.bartminski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180727141148.30874-5-jakub.bartminski@intel.com

drivers/gpu/drm/i915/intel_wopcm.c

@@ -168,6 +168,9 @@ int intel_wopcm_init(struct intel_wopcm *wopcm)
 
 	GEM_BUG_ON(!wopcm->size);
 
+	if (i915_inject_load_failure())
+		return -E2BIG;
+
 	if (guc_fw_size >= wopcm->size) {
 		DRM_ERROR("GuC FW (%uKiB) is too big to fit in WOPCM.",
 			  guc_fw_size / 1024);