drm/i915/uc: Update drawing for firmware layout

Sphinx was rendering firmware layout as html table, but since
we want to add sizes relations switch to plain text graphics.

v2: also update text and do it before move (Daniele)
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190725141308.24660-2-michal.wajdeczko@intel.com

Documentation/gpu/i915.rst

@@ -430,6 +430,12 @@ WOPCM Layout
 GuC
 ===
 
+Firmware Layout
+-------------------
+
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h
+   :doc: Firmware Layout
+
 GuC-specific firmware loader
 ----------------------------
 
@@ -445,12 +451,6 @@ GuC-based command submission
 .. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
    :internal:
 
-GuC Firmware Layout
--------------------
-
-.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h
-   :doc: GuC Firmware Layout
-
 GuC Address Space
 -----------------
 

drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h

@@ -122,23 +122,20 @@
 #define GUC_CTL_MAX_DWORDS		(SOFT_SCRATCH_COUNT - 2) /* [1..14] */
 
 /**
- * DOC: GuC Firmware Layout
+ * DOC: Firmware Layout
  *
- * The GuC firmware layout looks like this:
+ * The GuC/HuC firmware layout looks like this::
  *
- *     +-------------------------------+
- *     |         uc_css_header         |
- *     |                               |
- *     | contains major/minor version  |
- *     +-------------------------------+
- *     |             uCode             |
- *     +-------------------------------+
- *     |         RSA signature         |
- *     +-------------------------------+
- *     |          modulus key          |
- *     +-------------------------------+
- *     |          exponent val         |
- *     +-------------------------------+
+ *      +======================================================================+
+ *      |  Firmware blob                                                       |
+ *      +===============+===============+============+============+============+
+ *      |  CSS header   |     uCode     |  RSA key   |  modulus   |  exponent  |
+ *      +===============+===============+============+============+============+
+ *       <-header size->                 <---header size continued ----------->
+ *       <--- size ----------------------------------------------------------->
+ *                                       <-key size->
+ *                                                    <-mod size->
+ *                                                                 <-exp size->
  *
  * The firmware may or may not have modulus key and exponent data. The header,
  * uCode and RSA signature are must-have components that will be used by driver.
@@ -155,8 +152,8 @@
  * 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.
- * Only HuC version information is saved in a different way.
+ * The only difference between GuC and HuC firmwares is how the version
+ * information is saved.
  */
 
 struct uc_css_header {