[Intel-gfx] [PATCH 8/8] drm/i915/uc: Simplify firwmare path handling

[Arkadiusz Hiler]

Currently fw->path values can represent one of three possible states:

 1) NULL - device without the uC
 2) '\0' - device with the uC but have no firmware
 3) else - device with the uC and we have firmware

Second case is used only to WARN at a later stage.

We can WARN right away and merge cases 1 and 2.

Code can be even further simplified and common (HuC/GuC logic) happening
right before the fetch can be offloaded to the common function.

v2: fewer temporary variables, more straightforward flow (M. Wajdeczko)

Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Michal Winiarski <michal.winiarski at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler at intel.com>
---
 drivers/gpu/drm/i915/intel_guc_loader.c | 39 +++++++++++----------------------
 drivers/gpu/drm/i915/intel_huc.c        | 20 +++++------------
 drivers/gpu/drm/i915/intel_uc.c         |  5 +++--
 3 files changed, 22 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
index 549a254..aade185 100644
--- a/drivers/gpu/drm/i915/intel_guc_loader.c
+++ b/drivers/gpu/drm/i915/intel_guc_loader.c
@@ -433,12 +433,8 @@ int intel_guc_init_hw(struct drm_i915_private *dev_priv)
 		intel_uc_fw_status_repr(guc_fw->load_status));
 
 	if (fw_path == NULL) {
-		/* Device is known to have no uCode (e.g. no GuC) */
+		/* We do not have uCode for the device */
 		return -ENXIO;
-	} else if (*fw_path == '\0') {
-		/* Device has a GuC but we don't know what f/w to load? */
-		WARN(1, "No GuC firmware known for this platform!\n");
-		return -ENODEV;
 	}
 
 	/* Fetch failed, or already fetched but failed to load? */
@@ -474,7 +470,6 @@ int intel_guc_init_hw(struct drm_i915_private *dev_priv)
 	return 0;
 }
 
-
 /**
  * intel_guc_fetch_fw() - determine and fetch firmware
  * @guc:	intel_guc struct
@@ -487,39 +482,31 @@ int intel_guc_init_hw(struct drm_i915_private *dev_priv)
 void intel_guc_fetch_fw(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
-	const char *fw_path;
 
-	if (!HAS_GUC_UCODE(dev_priv)) {
-		fw_path = NULL;
-	} else if (IS_SKYLAKE(dev_priv)) {
-		fw_path = I915_SKL_GUC_UCODE;
+	guc->fw.path = NULL;
+	guc->fw.fetch_status = INTEL_UC_FIRMWARE_NONE;
+	guc->fw.load_status = INTEL_UC_FIRMWARE_NONE;
+	guc->fw.fw = INTEL_UC_FW_TYPE_GUC;
+
+	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;
 	} else if (IS_BROXTON(dev_priv)) {
-		fw_path = I915_BXT_GUC_UCODE;
+		guc->fw.path = I915_BXT_GUC_UCODE;
 		guc->fw.major_ver_wanted = BXT_FW_MAJOR;
 		guc->fw.minor_ver_wanted = BXT_FW_MINOR;
 	} else if (IS_KABYLAKE(dev_priv)) {
-		fw_path = I915_KBL_GUC_UCODE;
+		guc->fw.path = I915_KBL_GUC_UCODE;
 		guc->fw.major_ver_wanted = KBL_FW_MAJOR;
 		guc->fw.minor_ver_wanted = KBL_FW_MINOR;
 	} else {
-		fw_path = "";	/* unknown device */
+		WARN(1, "No GuC firmware known for platform with GuC!\n");
+		i915.enable_guc_loading = 0;
+		return;
 	}
 
-	guc->fw.path = fw_path;
-	guc->fw.fetch_status = INTEL_UC_FIRMWARE_NONE;
-	guc->fw.load_status = INTEL_UC_FIRMWARE_NONE;
-
-	if (fw_path == NULL)
-		return;
-	if (*fw_path == '\0')
-		return;
-
-	guc->fw.fetch_status = INTEL_UC_FIRMWARE_PENDING;
-	DRM_DEBUG_DRIVER("GuC firmware pending, path %s\n", fw_path);
 	guc->fw.fetch(dev_priv, &guc->fw);
-	/* status must now be FAIL or SUCCESS */
 }
 
 /**
diff --git a/drivers/gpu/drm/i915/intel_huc.c b/drivers/gpu/drm/i915/intel_huc.c
index 7527988..c94e22f 100644
--- a/drivers/gpu/drm/i915/intel_huc.c
+++ b/drivers/gpu/drm/i915/intel_huc.c
@@ -155,37 +155,29 @@ static int huc_ucode_xfer(struct drm_i915_private *dev_priv)
 void intel_huc_fetch_fw(struct intel_huc *huc)
 {
 	struct drm_i915_private *dev_priv = huc_to_i915(huc);
-	const char *fw_path = NULL;
 
 	huc->fw.path = NULL;
 	huc->fw.fetch_status = INTEL_UC_FIRMWARE_NONE;
 	huc->fw.load_status = INTEL_UC_FIRMWARE_NONE;
 	huc->fw.fw = INTEL_UC_FW_TYPE_HUC;
 
-	if (!HAS_HUC_UCODE(dev_priv))
-		return;
-
 	if (IS_SKYLAKE(dev_priv)) {
-		fw_path = I915_SKL_HUC_UCODE;
+		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;
 	} else if (IS_BROXTON(dev_priv)) {
-		fw_path = I915_BXT_HUC_UCODE;
+		huc->fw.path = I915_BXT_HUC_UCODE;
 		huc->fw.major_ver_wanted = BXT_HUC_FW_MAJOR;
 		huc->fw.minor_ver_wanted = BXT_HUC_FW_MINOR;
 	} else if (IS_KABYLAKE(dev_priv)) {
-		fw_path = I915_KBL_HUC_UCODE;
+		huc->fw.path = I915_KBL_HUC_UCODE;
 		huc->fw.major_ver_wanted = KBL_HUC_FW_MAJOR;
 		huc->fw.minor_ver_wanted = KBL_HUC_FW_MINOR;
+	} else {
+		WARN(1, "No HuC firmware known for platform with HuC!\n");
+		return;
 	}
 
-	huc->fw.path = fw_path;
-	huc->fw.fetch_status = INTEL_UC_FIRMWARE_PENDING;
-
-	DRM_DEBUG_DRIVER("HuC firmware pending, path %s\n", fw_path);
-
-	WARN(huc->fw.path == NULL, "HuC present but no fw path\n");
-
 	huc->fw.fetch(dev_priv, &huc->fw);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index 2bb49b7..6f2d3f6 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -267,8 +267,9 @@ static void uc_fetch_fw(struct drm_i915_private *dev_priv,
 	size_t size;
 	int err;
 
-	DRM_DEBUG_DRIVER("before requesting firmware: uC fw fetch status %s\n",
-		intel_uc_fw_status_repr(uc_fw->fetch_status));
+	uc_fw->fetch_status = INTEL_UC_FIRMWARE_PENDING;
+
+	DRM_DEBUG_DRIVER("uC firmware pending, path %s\n", uc_fw->path);
 
 	err = request_firmware(&fw, uc_fw->path, &pdev->dev);
 	if (err)
-- 
2.9.3