drm/xe/wopcm: fix WOPCM size for LNL+

Starting on LNL the WOPCM size is 8MB instead of 4, so we need to avoid
using the [0, 8MB) range of the GGTT as that can be unaccessible from
the microcontrollers.

Note that the proper long-term fix here is to read the WOPCM size from
the HW, but that is a more serious rework that would be difficult to
backport, so we can do that as a follow-up.

Fixes: 9c57bc0 ("drm/xe/lnl: Drop force_probe requirement")
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Shuicheng Lin <shuicheng.lin@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Shuicheng Lin <shuicheng.lin@intel.com>
Link: https://patch.msgid.link/20260713221758.3285744-2-daniele.ceraolospurio@intel.com
(cherry picked from commit 3033b0b)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

Author: dceraolo

drivers/gpu/drm/xe/xe_wopcm.c

@@ -49,9 +49,9 @@
  */
 
 /* Default WOPCM size is 2MB from Gen11, 1MB on previous platforms */
-/* FIXME: Larger size require for 2 tile PVC, do a proper probe sooner or later */
+/* FIXME: Larger size require for some platforms, do a proper probe sooner or later */
 #define DGFX_WOPCM_SIZE			SZ_4M
-/* FIXME: Larger size require for MTL, do a proper probe sooner or later */
+#define LNL_WOPCM_SIZE			SZ_8M
 #define MTL_WOPCM_SIZE			SZ_4M
 #define WOPCM_SIZE			SZ_2M
 
@@ -179,9 +179,14 @@ static int __wopcm_init_regs(struct xe_device *xe, struct xe_gt *gt,
 
 u32 xe_wopcm_size(struct xe_device *xe)
 {
-	return IS_DGFX(xe) ? DGFX_WOPCM_SIZE :
-		xe->info.platform == XE_METEORLAKE ? MTL_WOPCM_SIZE :
-		WOPCM_SIZE;
+	if (xe->info.platform >= XE_LUNARLAKE)
+		return LNL_WOPCM_SIZE;
+	else if (IS_DGFX(xe))
+		return DGFX_WOPCM_SIZE;
+	else if (xe->info.platform == XE_METEORLAKE)
+		return MTL_WOPCM_SIZE;
+	else
+		return WOPCM_SIZE;
 }
 
 static u32 max_wopcm_size(struct xe_device *xe)