1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/display/xe_panic.c b/drivers/gpu/drm/xe/display/xe_panic.c
new file mode 100644
index 000000000000..df663286092a
--- /dev/null
+++ b/drivers/gpu/drm/xe/display/xe_panic.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: MIT
+/* Copyright © 2025 Intel Corporation */
+
+#include <drm/drm_cache.h>
+#include <drm/drm_panic.h>
+
+#include "intel_display_types.h"
+#include "intel_fb.h"
+#include "intel_panic.h"
+#include "xe_bo.h"
+#include "xe_res_cursor.h"
+
+struct intel_panic {
+	struct xe_res_cursor res;
+	struct iosys_map vmap;
+
+	int page;
+};
+
+static void xe_panic_kunmap(struct intel_panic *panic)
+{
+	if (!panic->vmap.is_iomem && iosys_map_is_set(&panic->vmap)) {
+		drm_clflush_virt_range(panic->vmap.vaddr, PAGE_SIZE);
+		kunmap_local(panic->vmap.vaddr);
+	}
+	iosys_map_clear(&panic->vmap);
+	panic->page = -1;
+}
+
+/*
+ * The scanout buffer pages are not mapped, so for each pixel,
+ * use kmap_local_page_try_from_panic() to map the page, and write the pixel.
+ * Try to keep the map from the previous pixel, to avoid too much map/unmap.
+ */
+static void xe_panic_page_set_pixel(struct drm_scanout_buffer *sb, unsigned int x,
+				    unsigned int y, u32 color)
+{
+	struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
+	struct intel_panic *panic = fb->panic;
+	struct xe_bo *bo = gem_to_xe_bo(intel_fb_bo(&fb->base));
+	unsigned int new_page;
+	unsigned int offset;
+
+	if (fb->panic_tiling)
+		offset = fb->panic_tiling(sb->width, x, y);
+	else
+		offset = y * sb->pitch[0] + x * sb->format->cpp[0];
+
+	new_page = offset >> PAGE_SHIFT;
+	offset = offset % PAGE_SIZE;
+	if (new_page != panic->page) {
+		if (xe_bo_is_vram(bo)) {
+			/* Display is always mapped on root tile */
+			struct xe_vram_region *vram = xe_bo_device(bo)->mem.vram;
+
+			if (panic->page < 0 || new_page < panic->page) {
+				xe_res_first(bo->ttm.resource, new_page * PAGE_SIZE,
+					     bo->ttm.base.size - new_page * PAGE_SIZE, &panic->res);
+			} else {
+				xe_res_next(&panic->res, PAGE_SIZE * (new_page - panic->page));
+			}
+			iosys_map_set_vaddr_iomem(&panic->vmap,
+						  vram->mapping + panic->res.start);
+		} else {
+			xe_panic_kunmap(panic);
+			iosys_map_set_vaddr(&panic->vmap,
+					    ttm_bo_kmap_try_from_panic(&bo->ttm,
+								       new_page));
+		}
+		panic->page = new_page;
+	}
+
+	if (iosys_map_is_set(&panic->vmap))
+		iosys_map_wr(&panic->vmap, offset, u32, color);
+}
+
+struct intel_panic *intel_panic_alloc(void)
+{
+	struct intel_panic *panic;
+
+	panic = kzalloc(sizeof(*panic), GFP_KERNEL);
+
+	return panic;
+}
+
+int intel_panic_setup(struct intel_panic *panic, struct drm_scanout_buffer *sb)
+{
+	struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
+	struct xe_bo *bo = gem_to_xe_bo(intel_fb_bo(&fb->base));
+
+	if (xe_bo_is_vram(bo) && !xe_bo_is_visible_vram(bo))
+		return -ENODEV;
+
+	panic->page = -1;
+	sb->set_pixel = xe_panic_page_set_pixel;
+	return 0;
+}
+
+void intel_panic_finish(struct intel_panic *panic)
+{
+	xe_panic_kunmap(panic);
+}