drm/i915: Add HuC firmware size related restriction for Gen9 and CNL A0

On CNL A0 and Gen9, there's a hardware restriction that requires the
available GuC WOPCM size to be larger than or equal to HuC firmware size.

This patch adds new verification code to ensure the available GuC WOPCM
size to be larger than or equal to HuC firmware size on both Gen9 and CNL
A0.

v6:
 - Extended HuC FW size check against GuC WOPCM size to all
   Gen9 and CNL A0 platforms

v7:
 - Fixed patch format issues

v8:
 - Renamed variables and functions to avoid ambiguity (Joonas)
 - Updated commit message and comments to be more comprehensive (Sagar)

v9:
 - Moved code that is not related to restriction check into a separate
   patch and updated the commit message accordingly (Sagar/Michal)
 - Avoided to call uc_get_fw_size for better layer isolation (Michal)

v10:
 - Shorten function names and reorganized size_check code to have clear
   isolation (Joonas)
 - Removed unnecessary comments (Joonas)

v11:
 - Fixed logic error in size check (Michal)

v12:
 - Add space between "HuC FW" and "(%uKiB)" in error message (Michal)

v13:
 - Updated the ordering of s-o-b/cc/r-b tags (Sagar)

BSpec: 10875
Signed-off-by: Jackie Li <yaodong.li@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: John Spotswood <john.a.spotswood@intel.com>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> (v8)
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com> (v11)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v12)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1520987574-19351-4-git-send-email-yaodong.li@intel.com

drivers/gpu/drm/i915/intel_wopcm.c

@@ -105,14 +105,36 @@ static inline int gen9_check_dword_gap(u32 guc_wopcm_base, u32 guc_wopcm_size)
 	return 0;
 }
 
+static inline int gen9_check_huc_fw_fits(u32 guc_wopcm_size, u32 huc_fw_size)
+{
+	/*
+	 * On Gen9 & CNL A0, hardware requires the total available GuC WOPCM
+	 * size to be larger than or equal to HuC firmware size. Otherwise,
+	 * firmware uploading would fail.
+	 */
+	if (huc_fw_size > guc_wopcm_size - GUC_WOPCM_RESERVED) {
+		DRM_ERROR("HuC FW (%uKiB) won't fit in GuC WOPCM (%uKiB).\n",
+			  huc_fw_size / 1024,
+			  (guc_wopcm_size - GUC_WOPCM_RESERVED) / 1024);
+		return -E2BIG;
+	}
+
+	return 0;
+}
+
 static inline int check_hw_restriction(struct drm_i915_private *i915,
-				       u32 guc_wopcm_base, u32 guc_wopcm_size)
+				       u32 guc_wopcm_base, u32 guc_wopcm_size,
+				       u32 huc_fw_size)
 {
 	int err = 0;
 
 	if (IS_GEN9(i915))
 		err = gen9_check_dword_gap(guc_wopcm_base, guc_wopcm_size);
 
+	if (!err &&
+	    (IS_GEN9(i915) || IS_CNL_REVID(i915, CNL_REVID_A0, CNL_REVID_A0)))
+		err = gen9_check_huc_fw_fits(guc_wopcm_size, huc_fw_size);
+
 	return err;
 }
 
@@ -175,7 +197,8 @@ int intel_wopcm_init(struct intel_wopcm *wopcm)
 		return -E2BIG;
 	}
 
-	err = check_hw_restriction(i915, guc_wopcm_base, guc_wopcm_size);
+	err = check_hw_restriction(i915, guc_wopcm_base, guc_wopcm_size,
+				   huc_fw_size);
 	if (err)
 		return err;