[v2 1/2] drm/xe/fbdev: Limit the usage of stolen for LNL+

[Uma Shankar]

As per recommendation in the workarounds:
WA_22019338487

There is an issue with accessing Stolen memory pages due a
hardware limitation. Limit the usage of stolen memory for
fbdev for LNL+. Don't use BIOS FB from stolen on LNL+ and
assign the same from system memory.

v2: Corrected the WA Number, limited WA to LNL and
    Adopted XE_WA framework as suggested by Lucas and Matt.

Signed-off-by: Uma Shankar <uma.shankar at intel.com>
---
 drivers/gpu/drm/xe/display/intel_fbdev_fb.c   | 20 ++++++++++++++++++-
 drivers/gpu/drm/xe/display/xe_plane_initial.c | 12 +++++++++++
 drivers/gpu/drm/xe/xe_wa_oob.rules            |  1 +
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/display/intel_fbdev_fb.c b/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
index 816ad13821a8..9c70c9158108 100644
--- a/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
+++ b/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
@@ -10,6 +10,8 @@
 #include "xe_bo.h"
 #include "xe_gt.h"
 #include "xe_ttm_stolen_mgr.h"
+#include "xe_wa.h"
+#include <generated/xe_wa_oob.h>
 
 struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
 					       struct drm_fb_helper_surface_size *sizes)
@@ -20,6 +22,9 @@ struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
 	struct drm_mode_fb_cmd2 mode_cmd = {};
 	struct drm_i915_gem_object *obj;
 	int size;
+	bool wa_22019338487 = false;
+	struct xe_gt *gt;
+	u8 id;
 
 	/* we don't do packed 24bpp */
 	if (sizes->surface_bpp == 24)
@@ -37,7 +42,19 @@ struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
 	size = PAGE_ALIGN(size);
 	obj = ERR_PTR(-ENODEV);
 
-	if (!IS_DGFX(xe)) {
+	/*
+	 * WA_22019338487:
+	 * There is an issue with accessing Stolen memory pages
+	 * due a hardware limitation. Limit the usage of stolen
+	 * memory for fbdev for LNL+. Don't use BIOS FB from
+	 * stolen on LNL+ and assign the same from system memory
+	 */
+	for_each_gt(gt, xe, id) {
+		if (XE_WA(gt, 22019338487))
+			wa_22019338487 = true;
+	}
+
+	if (!IS_DGFX(xe) && !wa_22019338487) {
 		obj = xe_bo_create_pin_map(xe, xe_device_get_root_tile(xe),
 					   NULL, size,
 					   ttm_bo_type_kernel, XE_BO_FLAG_SCANOUT |
@@ -48,6 +65,7 @@ struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
 		else
 			drm_info(&xe->drm, "Allocated fbdev into stolen failed: %li\n", PTR_ERR(obj));
 	}
+
 	if (IS_ERR(obj)) {
 		obj = xe_bo_create_pin_map(xe, xe_device_get_root_tile(xe), NULL, size,
 					   ttm_bo_type_kernel, XE_BO_FLAG_SCANOUT |
diff --git a/drivers/gpu/drm/xe/display/xe_plane_initial.c b/drivers/gpu/drm/xe/display/xe_plane_initial.c
index 5eccd6abb3ef..7e93ddad6df8 100644
--- a/drivers/gpu/drm/xe/display/xe_plane_initial.c
+++ b/drivers/gpu/drm/xe/display/xe_plane_initial.c
@@ -18,6 +18,8 @@
 #include "intel_frontbuffer.h"
 #include "intel_plane_initial.h"
 #include "xe_bo.h"
+#include "xe_wa.h"
+#include <generated/xe_wa_oob.h>
 
 static bool
 intel_reuse_initial_plane_obj(struct intel_crtc *this,
@@ -104,6 +106,16 @@ initial_plane_bo(struct xe_device *xe,
 		phys_base = base;
 		flags |= XE_BO_FLAG_STOLEN;
 
+		/*
+		 * WA_22019338487:
+		 * There is an issue with accessing Stolen memory pages
+		 * due a hardware limitation. Limit the usage of stolen
+		 * memory for fbdev for LNL+. Don't use BIOS FB from
+		 * stolen on LNL+ and assign the same from system memory
+		 */
+		if (XE_WA(tile0->primary_gt, 22019338487))
+			return NULL;
+
 		/*
 		 * If the FB is too big, just don't use it since fbdev is not very
 		 * important and we should probably use that space with FBC or other
diff --git a/drivers/gpu/drm/xe/xe_wa_oob.rules b/drivers/gpu/drm/xe/xe_wa_oob.rules
index 08f7336881e3..9b08fedbf85c 100644
--- a/drivers/gpu/drm/xe/xe_wa_oob.rules
+++ b/drivers/gpu/drm/xe/xe_wa_oob.rules
@@ -29,4 +29,5 @@
 13011645652	GRAPHICS_VERSION(2004)
 22019338487	MEDIA_VERSION(2000)
 		GRAPHICS_VERSION(2001)
+		GRAPHICS_VERSION(2004)
 16023588340	GRAPHICS_VERSION(2001)
-- 
2.42.0