drm/i915/uc: Add params for specifying firmware

`guc_firmware_path` and `huc_firmware_path` module parameters are added.

Using the parameter disables version checks and loads desired firmware
instead of the default one.

v2: make params unsafe && notice about disabled fw check (J. Lahtinen)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/i915_params.c

@@ -59,6 +59,8 @@ struct i915_params i915 __read_mostly = {
 	.enable_guc_loading = 0,
 	.enable_guc_submission = 0,
 	.guc_log_level = -1,
+	.guc_firmware_path = NULL,
+	.huc_firmware_path = NULL,
 	.enable_dp_mst = true,
 	.inject_load_failure = 0,
 	.enable_dpcd_backlight = false,
@@ -230,6 +232,14 @@ module_param_named(guc_log_level, i915.guc_log_level, int, 0400);
 MODULE_PARM_DESC(guc_log_level,
 	"GuC firmware logging level (-1:disabled (default), 0-3:enabled)");
 
+module_param_named_unsafe(guc_firmware_path, i915.guc_firmware_path, charp, 0400);
+MODULE_PARM_DESC(guc_firmware_path,
+	"GuC firmware path to use instead of the default one");
+
+module_param_named_unsafe(huc_firmware_path, i915.huc_firmware_path, charp, 0400);
+MODULE_PARM_DESC(huc_firmware_path,
+	"HuC firmware path to use instead of the default one");
+
 module_param_named_unsafe(enable_dp_mst, i915.enable_dp_mst, bool, 0600);
 MODULE_PARM_DESC(enable_dp_mst,
 	"Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");

drivers/gpu/drm/i915/i915_params.h

@@ -46,6 +46,8 @@
 	func(int, enable_guc_loading); \
 	func(int, enable_guc_submission); \
 	func(int, guc_log_level); \
+	func(char *, guc_firmware_path); \
+	func(char *, huc_firmware_path); \
 	func(int, use_mmio_flip); \
 	func(int, mmio_debug); \
 	func(int, edp_vswing); \

drivers/gpu/drm/i915/intel_guc_loader.c

@@ -407,7 +407,11 @@ int intel_guc_select_fw(struct intel_guc *guc)
 	guc->fw.load_status = INTEL_UC_FIRMWARE_NONE;
 	guc->fw.fw = INTEL_UC_FW_TYPE_GUC;
 
-	if (IS_SKYLAKE(dev_priv)) {
+	if (i915.guc_firmware_path) {
+		guc->fw.path = i915.guc_firmware_path;
+		guc->fw.major_ver_wanted = 0;
+		guc->fw.minor_ver_wanted = 0;
+	} else if (IS_SKYLAKE(dev_priv)) {
 		guc->fw.path = I915_SKL_GUC_UCODE;
 		guc->fw.major_ver_wanted = SKL_FW_MAJOR;
 		guc->fw.minor_ver_wanted = SKL_FW_MINOR;

drivers/gpu/drm/i915/intel_huc.c

@@ -153,7 +153,11 @@ void intel_huc_select_fw(struct intel_huc *huc)
 	huc->fw.load_status = INTEL_UC_FIRMWARE_NONE;
 	huc->fw.fw = INTEL_UC_FW_TYPE_HUC;
 
-	if (IS_SKYLAKE(dev_priv)) {
+	if (i915.huc_firmware_path) {
+		huc->fw.path = i915.huc_firmware_path;
+		huc->fw.major_ver_wanted = 0;
+		huc->fw.minor_ver_wanted = 0;
+	} else if (IS_SKYLAKE(dev_priv)) {
 		huc->fw.path = I915_SKL_HUC_UCODE;
 		huc->fw.major_ver_wanted = SKL_HUC_FW_MAJOR;
 		huc->fw.minor_ver_wanted = SKL_HUC_FW_MINOR;

drivers/gpu/drm/i915/intel_uc.c

@@ -356,8 +356,10 @@ void intel_uc_prepare_fw(struct drm_i915_private *dev_priv,
 		goto fail;
 	}
 
-	if (uc_fw->major_ver_found != uc_fw->major_ver_wanted ||
-	    uc_fw->minor_ver_found < uc_fw->minor_ver_wanted) {
+	if (uc_fw->major_ver_wanted == 0 && uc_fw->minor_ver_wanted == 0) {
+		DRM_NOTE("Skipping uC firmware version check\n");
+	} else if (uc_fw->major_ver_found != uc_fw->major_ver_wanted ||
+		   uc_fw->minor_ver_found < uc_fw->minor_ver_wanted) {
 		DRM_NOTE("uC firmware version %d.%d, required %d.%d\n",
 			uc_fw->major_ver_found, uc_fw->minor_ver_found,
 			uc_fw->major_ver_wanted, uc_fw->minor_ver_wanted);