drm: Nuke modifier[1-3]

It has been suggested that having per-plane modifiers is making life
more difficult for userspace, so let's just retire modifier[1-3] and
use modifier[0] to apply to the entire framebuffer.

Obviosuly this means that if individual planes need different tiling
layouts and whatnot we will need a new modifier for each combination
of planes with different tiling layouts.

For a bit of extra backwards compatilbilty the kernel will allow
non-zero modifier[1+] but it require that they will match modifier[0].
This in case there's existing userspace out there that sets
modifier[1+] to something non-zero with planar formats.

Mostly a cocci job, with a bit of manual stuff mixed in.

@@
struct drm_framebuffer *fb;
expression E;
@@
- fb->modifier[E]
+ fb->modifier

@@
struct drm_framebuffer fb;
expression E;
@@
- fb.modifier[E]
+ fb.modifier

Cc: Kristian Høgsberg <hoegsberg@gmail.com>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tomeu Vizoso <tomeu@tomeuvizoso.net>
Cc: dczaplejewicz@collabora.co.uk
Suggested-by: Kristian Høgsberg <hoegsberg@gmail.com>
Acked-by: Ben Widawsky <ben@bwidawsk.net>
Acked-by: Daniel Stone <daniels@collabora.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1479295996-26246-1-git-send-email-ville.syrjala@linux.intel.com

include/uapi/drm/drm_mode.h

@@ -408,17 +408,20 @@ struct drm_mode_fb_cmd2 {
 	 * offsets[1].  Note that offsets[0] will generally
 	 * be 0 (but this is not required).
 	 *
-	 * To accommodate tiled, compressed, etc formats, a per-plane
+	 * To accommodate tiled, compressed, etc formats, a
 	 * modifier can be specified.  The default value of zero
 	 * indicates "native" format as specified by the fourcc.
-	 * Vendor specific modifier token.  This allows, for example,
-	 * different tiling/swizzling pattern on different planes.
-	 * See discussion above of DRM_FORMAT_MOD_xxx.
+	 * Vendor specific modifier token.  Note that even though
+	 * it looks like we have a modifier per-plane, we in fact
+	 * do not. The modifier for each plane must be identical.
+	 * Thus all combinations of different data layouts for
+	 * multi plane formats must be enumerated as separate
+	 * modifiers.
 	 */
 	__u32 handles[4];
 	__u32 pitches[4]; /* pitch for each plane */
 	__u32 offsets[4]; /* offset of each plane */
-	__u64 modifier[4]; /* ie, tiling, compressed (per plane) */
+	__u64 modifier[4]; /* ie, tiling, compress */
 };
 
 #define DRM_MODE_FB_DIRTY_ANNOTATE_COPY 0x01