drm/i915/huc: Load HuC only if requested

Our new "enable_guc" modparam allows to control whenever HuC
should be loaded. However existing code will try load and
authenticate HuC always when we use the GuC. This patch is
trying to enforce modparam selection.

v2: no need to cast PTR_ERR (Chris)
    fetch/fini only if required (Michal)
    fix wrong break (Sagar)
v3: add new goto label (Sagar)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171206135316.32556-7-michal.wajdeczko@intel.com

drivers/gpu/drm/i915/intel_huc.c

@@ -181,17 +181,17 @@ static int huc_ucode_xfer(struct intel_uc_fw *huc_fw, struct i915_vma *vma)
  * intel_huc_init_hw() - load HuC uCode to device
  * @huc: intel_huc structure
  *
- * Called from guc_setup() during driver loading and also after a GPU reset.
- * Be note that HuC loading must be done before GuC loading.
+ * Called from intel_uc_init_hw() during driver loading and also after a GPU
+ * reset. Be note that HuC loading must be done before GuC loading.
  *
  * The firmware image should have already been fetched into memory by the
- * earlier call to intel_huc_init(), so here we need only check that
+ * earlier call to intel_uc_init_fw(), so here we need only check that
  * is succeeded, and then transfer the image to the h/w.
  *
  */
-void intel_huc_init_hw(struct intel_huc *huc)
+int intel_huc_init_hw(struct intel_huc *huc)
 {
-	intel_uc_fw_upload(&huc->fw, huc_ucode_xfer);
+	return intel_uc_fw_upload(&huc->fw, huc_ucode_xfer);
 }
 
 /**
@@ -205,7 +205,7 @@ void intel_huc_init_hw(struct intel_huc *huc)
  * signature through intel_guc_auth_huc(). It then waits for 50ms for
  * firmware verification ACK and unpins the object.
  */
-void intel_huc_auth(struct intel_huc *huc)
+int intel_huc_auth(struct intel_huc *huc)
 {
 	struct drm_i915_private *i915 = huc_to_i915(huc);
 	struct intel_guc *guc = &i915->guc;
@@ -213,14 +213,14 @@ void intel_huc_auth(struct intel_huc *huc)
 	int ret;
 
 	if (huc->fw.load_status != INTEL_UC_FIRMWARE_SUCCESS)
-		return;
+		return -ENOEXEC;
 
 	vma = i915_gem_object_ggtt_pin(huc->fw.obj, NULL, 0, 0,
 				PIN_OFFSET_BIAS | GUC_WOPCM_TOP);
 	if (IS_ERR(vma)) {
-		DRM_ERROR("failed to pin huc fw object %d\n",
-				(int)PTR_ERR(vma));
-		return;
+		ret = PTR_ERR(vma);
+		DRM_ERROR("HuC: Failed to pin huc fw object %d\n", ret);
+		return ret;
 	}
 
 	ret = intel_guc_auth_huc(guc,
@@ -243,4 +243,5 @@ void intel_huc_auth(struct intel_huc *huc)
 
 out:
 	i915_vma_unpin(vma);
+	return ret;
 }

drivers/gpu/drm/i915/intel_huc.h

@@ -35,7 +35,7 @@ struct intel_huc {
 };
 
 void intel_huc_init_early(struct intel_huc *huc);
-void intel_huc_init_hw(struct intel_huc *huc);
-void intel_huc_auth(struct intel_huc *huc);
+int intel_huc_init_hw(struct intel_huc *huc);
+int intel_huc_auth(struct intel_huc *huc);
 
 #endif

drivers/gpu/drm/i915/intel_uc.c

@@ -119,7 +119,9 @@ void intel_uc_init_fw(struct drm_i915_private *dev_priv)
 	if (!USES_GUC(dev_priv))
 		return;
 
-	intel_uc_fw_fetch(dev_priv, &dev_priv->huc.fw);
+	if (USES_HUC(dev_priv))
+		intel_uc_fw_fetch(dev_priv, &dev_priv->huc.fw);
+
 	intel_uc_fw_fetch(dev_priv, &dev_priv->guc.fw);
 }
 
@@ -129,7 +131,9 @@ void intel_uc_fini_fw(struct drm_i915_private *dev_priv)
 		return;
 
 	intel_uc_fw_fini(&dev_priv->guc.fw);
-	intel_uc_fw_fini(&dev_priv->huc.fw);
+
+	if (USES_HUC(dev_priv))
+		intel_uc_fw_fini(&dev_priv->huc.fw);
 }
 
 /**
@@ -186,6 +190,7 @@ static void guc_disable_communication(struct intel_guc *guc)
 int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 {
 	struct intel_guc *guc = &dev_priv->guc;
+	struct intel_huc *huc = &dev_priv->huc;
 	int ret, attempts;
 
 	if (!USES_GUC(dev_priv))
@@ -233,7 +238,12 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 		if (ret)
 			goto err_submission;
 
-		intel_huc_init_hw(&dev_priv->huc);
+		if (USES_HUC(dev_priv)) {
+			ret = intel_huc_init_hw(huc);
+			if (ret)
+				goto err_submission;
+		}
+
 		intel_guc_init_params(guc);
 		ret = intel_guc_fw_upload(guc);
 		if (ret == 0 || ret != -EAGAIN)
@@ -251,7 +261,12 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 	if (ret)
 		goto err_log_capture;
 
-	intel_huc_auth(&dev_priv->huc);
+	if (USES_HUC(dev_priv)) {
+		ret = intel_huc_auth(huc);
+		if (ret)
+			goto err_communication;
+	}
+
 	if (USES_GUC_SUBMISSION(dev_priv)) {
 		if (i915_modparams.guc_log_level >= 0)
 			gen9_enable_guc_interrupts(dev_priv);
@@ -265,6 +280,8 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 		 guc->fw.major_ver_found, guc->fw.minor_ver_found);
 	dev_info(dev_priv->drm.dev, "GuC submission %s\n",
 		 enableddisabled(USES_GUC_SUBMISSION(dev_priv)));
+	dev_info(dev_priv->drm.dev, "HuC %s\n",
+		 enableddisabled(USES_HUC(dev_priv)));
 
 	return 0;
 
@@ -272,8 +289,9 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 	 * We've failed to load the firmware :(
 	 */
 err_interrupts:
-	guc_disable_communication(guc);
 	gen9_disable_guc_interrupts(dev_priv);
+err_communication:
+	guc_disable_communication(guc);
 err_log_capture:
 	guc_capture_load_err_log(guc);
 err_submission: