drm/i915/huc: Unified css_header struct for GuC and HuC

HuC firmware css header has almost exactly same definition as GuC
firmware except for the sw_version. Also, add a new member fw_type
into intel_uc_fw to indicate what kind of fw it is. So, the loader
will pull right sw_version from header.

v2: rebased on-top of drm-intel-nightly
v3: rebased. Rename device_id to guc_branch_client_version,
make guc_sw_version a union. <Jeff Mcgee>. Put UC_FW_TYPE_GUC
and UC_FW_TYPE_HUC into an enum.
v4: rebased on top of drm-tip.Update dev to dev_priv in
intel_uc_fw_fetch.
v5: rebased. Add INTEL_ prefix to an enum. Add fw_type declaration
from patch 1.Combine two different unions for huc and guc version,
reserved etc into one union with two structs.
v6: rebased. Change fw_type to enum.
v7: rebased. Rename the enum fw_type to intel_uc_fw_type.

Cc: Michal Wajdeczko <michal.wajdeczko.@intel.com>
Tested-by: Xiang Haihao <haihao.xiang@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Alex Dai <yu.dai@intel.com>
Signed-off-by: Peter Antoine <peter.antoine@intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1484356631-16139-3-git-send-email-anusha.srivatsa@intel.com

drivers/gpu/drm/i915/intel_guc_fwif.h

@@ -145,7 +145,7 @@
  * The GuC firmware layout looks like this:
  *
  *     +-------------------------------+
- *     |        guc_css_header         |
+ *     |         uc_css_header         |
  *     |                               |
  *     | contains major/minor version  |
  *     +-------------------------------+
@@ -172,9 +172,16 @@
  * 3. Length info of each component can be found in header, in dwords.
  * 4. Modulus and exponent key are not required by driver. They may not appear
  *    in fw. So driver will load a truncated firmware in this case.
+ *
+ * HuC firmware layout is same as GuC firmware.
+ *
+ * HuC firmware css header is different. However, the only difference is where
+ * the version information is saved. The uc_css_header is unified to support
+ * both. Driver should get HuC version from uc_css_header.huc_sw_version, while
+ * uc_css_header.guc_sw_version for GuC.
  */
 
-struct guc_css_header {
+struct uc_css_header {
 	uint32_t module_type;
 	/* header_size includes all non-uCode bits, including css_header, rsa
 	 * key, modulus key and exponent data. */
@@ -205,8 +212,16 @@ struct guc_css_header {
 
 	char username[8];
 	char buildnumber[12];
-	uint32_t device_id;
-	uint32_t guc_sw_version;
+	union {
+		struct {
+			uint32_t branch_client_version;
+			uint32_t sw_version;
+	} guc;
+		struct {
+			uint32_t sw_version;
+			uint32_t reserved;
+	} huc;
+	};
 	uint32_t prod_preprod_fw;
 	uint32_t reserved[12];
 	uint32_t header_info;

drivers/gpu/drm/i915/intel_guc_loader.c

@@ -589,7 +589,7 @@ void intel_uc_fw_fetch(struct drm_i915_private *dev_priv,
 	struct pci_dev *pdev = dev_priv->drm.pdev;
 	struct drm_i915_gem_object *obj;
 	const struct firmware *fw = NULL;
-	struct guc_css_header *css;
+	struct uc_css_header *css;
 	size_t size;
 	int err;
 
@@ -606,19 +606,19 @@ void intel_uc_fw_fetch(struct drm_i915_private *dev_priv,
 		uc_fw->path, fw);
 
 	/* Check the size of the blob before examining buffer contents */
-	if (fw->size < sizeof(struct guc_css_header)) {
+	if (fw->size < sizeof(struct uc_css_header)) {
 		DRM_NOTE("Firmware header is missing\n");
 		goto fail;
 	}
 
-	css = (struct guc_css_header *)fw->data;
+	css = (struct uc_css_header *)fw->data;
 
 	/* Firmware bits always start from header */
 	uc_fw->header_offset = 0;
 	uc_fw->header_size = (css->header_size_dw - css->modulus_size_dw -
 		css->key_size_dw - css->exponent_size_dw) * sizeof(u32);
 
-	if (uc_fw->header_size != sizeof(struct guc_css_header)) {
+	if (uc_fw->header_size != sizeof(struct uc_css_header)) {
 		DRM_NOTE("CSS header definition mismatch\n");
 		goto fail;
 	}
@@ -642,21 +642,36 @@ void intel_uc_fw_fetch(struct drm_i915_private *dev_priv,
 		goto fail;
 	}
 
-	/* Header and uCode will be loaded to WOPCM. Size of the two. */
-	size = uc_fw->header_size + uc_fw->ucode_size;
-	if (size > guc_wopcm_size(dev_priv)) {
-		DRM_NOTE("Firmware is too large to fit in WOPCM\n");
-		goto fail;
-	}
-
 	/*
 	 * The GuC firmware image has the version number embedded at a well-known
 	 * offset within the firmware blob; note that major / minor version are
 	 * TWO bytes each (i.e. u16), although all pointers and offsets are defined
 	 * in terms of bytes (u8).
 	 */
-	uc_fw->major_ver_found = css->guc_sw_version >> 16;
-	uc_fw->minor_ver_found = css->guc_sw_version & 0xFFFF;
+	switch (uc_fw->fw) {
+	case INTEL_UC_FW_TYPE_GUC:
+		/* Header and uCode will be loaded to WOPCM. Size of the two. */
+		size = uc_fw->header_size + uc_fw->ucode_size;
+
+		/* Top 32k of WOPCM is reserved (8K stack + 24k RC6 context). */
+		if (size > guc_wopcm_size(dev_priv)) {
+			DRM_ERROR("Firmware is too large to fit in WOPCM\n");
+			goto fail;
+		}
+		uc_fw->major_ver_found = css->guc.sw_version >> 16;
+		uc_fw->minor_ver_found = css->guc.sw_version & 0xFFFF;
+		break;
+
+	case INTEL_UC_FW_TYPE_HUC:
+		uc_fw->major_ver_found = css->huc.sw_version >> 16;
+		uc_fw->minor_ver_found = css->huc.sw_version & 0xFFFF;
+		break;
+
+	default:
+		DRM_ERROR("Unknown firmware type %d\n", uc_fw->fw);
+		err = -ENOEXEC;
+		goto fail;
+	}
 
 	if (uc_fw->major_ver_found != uc_fw->major_ver_wanted ||
 	    uc_fw->minor_ver_found < uc_fw->minor_ver_wanted) {

drivers/gpu/drm/i915/intel_uc.h

@@ -100,6 +100,11 @@ enum intel_uc_fw_status {
 	INTEL_UC_FIRMWARE_SUCCESS
 };
 
+enum intel_uc_fw_type {
+	INTEL_UC_FW_TYPE_GUC,
+	INTEL_UC_FW_TYPE_HUC
+};
+
 /*
  * This structure encapsulates all the data needed during the process
  * of fetching, caching, and loading the firmware image into the GuC.
@@ -116,6 +121,7 @@ struct intel_uc_fw {
 	uint16_t major_ver_found;
 	uint16_t minor_ver_found;
 
+	enum intel_uc_fw_type fw;
 	uint32_t header_size;
 	uint32_t header_offset;
 	uint32_t rsa_size;