[PATCH 11/12] drm/panic: Move panic display code into helper library

[Thomas Zimmermann <tzimmermann@suse.de>]

Move drm_plane_helper_display_panic_screen() and the existing panic-
display code into drm_panic_helper.c. Rename symbols accordingly.
Also update the QR-related code and the bindings accordingly.

Link the rsp. object file into drm_kms_helper.ko. Eventually the code
will become a DRM drawing library, together with DRM's format and draw
helpers. This requires more preparation. until then, KMS helpers serve
as a module. All DRM drivers link it anyway.

Add a new section about drawing helpers to the documentation of the KMS
helpers. List format and panic helpers there.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 Documentation/gpu/drm-kms-helpers.rst         |  11 +-
 MAINTAINERS                                   |   5 +-
 drivers/gpu/drm/Kconfig                       |   5 +
 drivers/gpu/drm/Makefile                      |   3 +-
 drivers/gpu/drm/drm_crtc_internal.h           |   2 -
 drivers/gpu/drm/drm_drv.c                     |   1 -
 drivers/gpu/drm/drm_kms_helper_common.c       |  14 +
 drivers/gpu/drm/drm_panic.c                   | 891 -----------------
 drivers/gpu/drm/drm_panic_helper.c            | 913 ++++++++++++++++++
 ...drm_panic_qr.rs => drm_panic_helper_qr.rs} |   4 +-
 drivers/gpu/drm/drm_panic_internal.h          |   4 +
 ...m_panic_test.c => drm_panic_helper_test.c} |  24 +-
 include/drm/drm_panic.h                       |   7 -
 include/drm/drm_panic_helper.h                |   5 +
 rust/bindings/bindings_helper.h               |   4 +-
 15 files changed, 972 insertions(+), 921 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_panic_helper.c
 rename drivers/gpu/drm/{drm_panic_qr.rs => drm_panic_helper_qr.rs} (99%)
 rename drivers/gpu/drm/tests/{drm_panic_test.c => drm_panic_helper_test.c} (88%)

diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index 94cfc26acecc..400cd0112713 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -118,12 +118,21 @@ fbdev Helper Functions Reference
 .. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
    :export:
 
-format Helper Functions Reference
+Draw Helper Functions Reference
 =================================
 
+Format-Conversion Helper Reference
+----------------------------------
+
 .. kernel-doc:: drivers/gpu/drm/drm_format_helper.c
    :export:
 
+Panic Helper Reference
+----------------------
+
+.. kernel-doc:: drivers/gpu/drm/drm_panic_helper.c
+   :export:
+
 Framebuffer DMA Helper Functions Reference
 ==========================================
 
diff --git a/MAINTAINERS b/MAINTAINERS
index f3dfdd9314bd..f7e7c6e2d285 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9019,8 +9019,9 @@ T:	git https://gitlab.freedesktop.org/drm/misc/kernel.git
 F:	drivers/gpu/drm/drm_draw.c
 F:	drivers/gpu/drm/drm_draw_internal.h
 F:	drivers/gpu/drm/drm_panic.c
+F:	drivers/gpu/drm/drm_panic_helper.c
 F:	drivers/gpu/drm/drm_panic_internal.h
-F:	drivers/gpu/drm/tests/drm_panic_test.c
+F:	drivers/gpu/drm/tests/drm_panic_helper_test.c
 F:	include/drm/drm_panic.h
 F:	include/drm/drm_panic_helper.h
 
@@ -9031,7 +9032,7 @@ L:	dri-devel@lists.freedesktop.org
 L:	rust-for-linux@vger.kernel.org
 S:	Supported
 T:	git https://gitlab.freedesktop.org/drm/misc/kernel.git
-F:	drivers/gpu/drm/drm_panic_qr.rs
+F:	drivers/gpu/drm/drm_panic_helper_qr.rs
 
 DRM PRIVACY-SCREEN CLASS
 M:	Hans de Goede <hansg@kernel.org>
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 323422861e8f..cdfd72d9a9c5 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -45,6 +45,7 @@ config DRM_MIPI_DSI
 config DRM_KMS_HELPER
 	tristate
 	depends on DRM
+	select DRM_PANIC_HELPER if DRM_PANIC
 	select FB_CORE if DRM_FBDEV_EMULATION
 	help
 	  CRTC helpers for KMS drivers.
@@ -130,6 +131,10 @@ config DRM_PANIC_SCREEN_QR_VERSION
 	  Smaller QR code are easier to read, but will contain less debugging
 	  data. Default is 40.
 
+config DRM_PANIC_HELPER
+	bool
+	depends on DRM_TTM
+
 config DRM_RAS
 	bool "DRM RAS support"
 	depends on DRM
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index e635fcffd379..f0c340aa2ec6 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -92,7 +92,6 @@ drm-$(CONFIG_DRM_PRIVACY_SCREEN) += \
 drm-$(CONFIG_DRM_ACCEL) += ../../accel/drm_accel.o
 drm-$(CONFIG_DRM_PANIC) += drm_panic.o
 drm-$(CONFIG_DRM_DRAW) += drm_draw.o
-drm-$(CONFIG_DRM_PANIC_SCREEN_QR_CODE) += drm_panic_qr.o
 drm-$(CONFIG_DRM_RAS) += drm_ras.o drm_ras_nl.o drm_ras_genl_family.o
 obj-$(CONFIG_DRM)	+= drm.o
 
@@ -157,6 +156,8 @@ drm_kms_helper-y := \
 	drm_simple_kms_helper.o \
 	drm_vblank_helper.o
 drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
+drm_kms_helper-$(CONFIG_DRM_PANIC_HELPER) += drm_panic_helper.o
+drm_kms_helper-$(CONFIG_DRM_PANIC_SCREEN_QR_CODE) += drm_panic_helper_qr.o
 drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
 obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
 
diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
index 83146ffef00c..3492787c3697 100644
--- a/drivers/gpu/drm/drm_crtc_internal.h
+++ b/drivers/gpu/drm/drm_crtc_internal.h
@@ -322,13 +322,11 @@ bool drm_panic_is_enabled(struct drm_device *dev);
 void drm_panic_register(struct drm_device *dev);
 void drm_panic_unregister(struct drm_device *dev);
 void drm_panic_init(void);
-void drm_panic_exit(void);
 #else
 static inline bool drm_panic_is_enabled(struct drm_device *dev) { return false; }
 static inline void drm_panic_register(struct drm_device *dev) {}
 static inline void drm_panic_unregister(struct drm_device *dev) {}
 static inline void drm_panic_init(void) {}
-static inline void drm_panic_exit(void) {}
 #endif
 
 #endif /* __DRM_CRTC_INTERNAL_H__ */
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 02ff02931515..1e813645b3eb 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -1248,7 +1248,6 @@ static void drm_core_exit(void)
 {
 	drm_ras_genl_family_unregister();
 	drm_privacy_screen_lookup_exit();
-	drm_panic_exit();
 	accel_core_exit();
 	unregister_chrdev(DRM_MAJOR, "drm");
 	drm_debugfs_remove_root();
diff --git a/drivers/gpu/drm/drm_kms_helper_common.c b/drivers/gpu/drm/drm_kms_helper_common.c
index 0c7550c0462b..b5d5b469b444 100644
--- a/drivers/gpu/drm/drm_kms_helper_common.c
+++ b/drivers/gpu/drm/drm_kms_helper_common.c
@@ -27,6 +27,20 @@
 
 #include <linux/module.h>
 
+#include "drm_panic_internal.h"
+
+static int __init drm_kms_helper_init(void)
+{
+	return drm_panic_helper_init();
+}
+module_init(drm_kms_helper_init);
+
+static void __exit drm_kms_helper_exit(void)
+{
+	drm_panic_helper_exit();
+}
+module_exit(drm_kms_helper_exit);
+
 MODULE_AUTHOR("David Airlie, Jesse Barnes");
 MODULE_DESCRIPTION("DRM KMS helper");
 MODULE_LICENSE("GPL and additional rights");
diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index b3a71fddf2de..c8b59a6e7f99 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -7,34 +7,22 @@
  */
 
 #include <linux/export.h>
-#include <linux/font.h>
-#include <linux/highmem.h>
 #include <linux/init.h>
-#include <linux/iosys-map.h>
 #include <linux/kdebug.h>
 #include <linux/kmsg_dump.h>
-#include <linux/linux_logo.h>
 #include <linux/list.h>
 #include <linux/math.h>
 #include <linux/module.h>
 #include <linux/overflow.h>
 #include <linux/printk.h>
 #include <linux/types.h>
-#include <linux/utsname.h>
-#include <linux/zlib.h>
 
 #include <drm/drm_drv.h>
-#include <drm/drm_fourcc.h>
-#include <drm/drm_framebuffer.h>
-#include <drm/drm_modeset_helper_vtables.h>
 #include <drm/drm_panic.h>
-#include <drm/drm_panic_helper.h>
 #include <drm/drm_plane.h>
 #include <drm/drm_print.h>
-#include <drm/drm_rect.h>
 
 #include "drm_crtc_internal.h"
-#include "drm_draw_internal.h"
 #include "drm_panic_internal.h"
 
 MODULE_AUTHOR("Jocelyn Falempe");
@@ -58,755 +46,10 @@ MODULE_LICENSE("GPL");
  * drm_plane_helper_display_panic_screen() for a generic implementation.
  */
 
-struct drm_panic_line {
-	u32 len;
-	const char *txt;
-};
-
-#define PANIC_LINE(s) {.len = sizeof(s) - 1, .txt = s}
-
-static struct drm_panic_line panic_msg[] = {
-	PANIC_LINE("KERNEL PANIC!"),
-	PANIC_LINE(""),
-	PANIC_LINE("Please reboot your computer."),
-	PANIC_LINE(""),
-	PANIC_LINE(""), /* will be replaced by the panic description */
-};
-
-static const size_t panic_msg_lines = ARRAY_SIZE(panic_msg);
-
-static const struct drm_panic_line logo_ascii[] = {
-	PANIC_LINE("     .--.        _"),
-	PANIC_LINE("    |o_o |      | |"),
-	PANIC_LINE("    |:_/ |      | |"),
-	PANIC_LINE("   //   \\ \\     |_|"),
-	PANIC_LINE("  (|     | )     _"),
-	PANIC_LINE(" /'\\_   _/`\\    (_)"),
-	PANIC_LINE(" \\___)=(___/"),
-};
-
-static const size_t logo_ascii_lines = ARRAY_SIZE(logo_ascii);
-
-#if defined(CONFIG_LOGO) && !defined(MODULE)
-static const struct linux_logo *logo_mono;
-
-static int drm_panic_setup_logo(void)
-{
-	const struct linux_logo *logo = fb_find_logo(1);
-	const unsigned char *logo_data;
-	struct linux_logo *logo_dup;
-
-	if (!logo || logo->type != LINUX_LOGO_MONO)
-		return 0;
-
-	/* The logo is __init, so we must make a copy for later use */
-	logo_data = kmemdup(logo->data,
-			    size_mul(DIV_ROUND_UP(logo->width, BITS_PER_BYTE), logo->height),
-			    GFP_KERNEL);
-	if (!logo_data)
-		return -ENOMEM;
-
-	logo_dup = kmemdup(logo, sizeof(*logo), GFP_KERNEL);
-	if (!logo_dup) {
-		kfree(logo_data);
-		return -ENOMEM;
-	}
-
-	logo_dup->data = logo_data;
-	logo_mono = logo_dup;
-
-	return 0;
-}
-
-device_initcall(drm_panic_setup_logo);
-#else
-#define logo_mono	((const struct linux_logo *)NULL)
-#endif
-
-/*
- *  Blit & Fill functions
- */
-static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip,
-				 const u8 *sbuf8, unsigned int spitch, unsigned int scale,
-				 u32 fg_color)
-{
-	unsigned int y, x;
-
-	for (y = 0; y < drm_rect_height(clip); y++)
-		for (x = 0; x < drm_rect_width(clip); x++)
-			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
-				sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color);
-}
-
-static void drm_panic_write_pixel16(void *vaddr, unsigned int offset, u16 color)
-{
-	u16 *p = vaddr + offset;
-
-	*p = color;
-}
-
-static void drm_panic_write_pixel24(void *vaddr, unsigned int offset, u32 color)
-{
-	u8 *p = vaddr + offset;
-
-	*p++ = color & 0xff;
-	color >>= 8;
-	*p++ = color & 0xff;
-	color >>= 8;
-	*p = color & 0xff;
-}
-
-/*
- * Special case if the pixel crosses page boundaries
- */
-static void drm_panic_write_pixel24_xpage(void *vaddr, struct page *next_page,
-					  unsigned int offset, u32 color)
-{
-	u8 *vaddr2;
-	u8 *p = vaddr + offset;
-
-	vaddr2 = kmap_local_page_try_from_panic(next_page);
-
-	*p++ = color & 0xff;
-	color >>= 8;
-
-	if (offset == PAGE_SIZE - 1)
-		p = vaddr2;
-
-	*p++ = color & 0xff;
-	color >>= 8;
-
-	if (offset == PAGE_SIZE - 2)
-		p = vaddr2;
-
-	*p = color & 0xff;
-	kunmap_local(vaddr2);
-}
-
-static void drm_panic_write_pixel32(void *vaddr, unsigned int offset, u32 color)
-{
-	u32 *p = vaddr + offset;
-
-	*p = color;
-}
-
-static void drm_panic_write_pixel(void *vaddr, unsigned int offset, u32 color, unsigned int cpp)
-{
-	switch (cpp) {
-	case 2:
-		drm_panic_write_pixel16(vaddr, offset, color);
-		break;
-	case 3:
-		drm_panic_write_pixel24(vaddr, offset, color);
-		break;
-	case 4:
-		drm_panic_write_pixel32(vaddr, offset, color);
-		break;
-	default:
-		pr_debug_once("Can't blit with pixel width %d\n", cpp);
-	}
-}
-
-/*
- * 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 drm_panic_blit_page(struct page **pages, unsigned int dpitch,
-				unsigned int cpp, const u8 *sbuf8,
-				unsigned int spitch, struct drm_rect *clip,
-				unsigned int scale, u32 fg32)
-{
-	unsigned int y, x;
-	unsigned int page = ~0;
-	unsigned int height = drm_rect_height(clip);
-	unsigned int width = drm_rect_width(clip);
-	void *vaddr = NULL;
-
-	for (y = 0; y < height; y++) {
-		for (x = 0; x < width; x++) {
-			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) {
-				unsigned int new_page;
-				unsigned int offset;
-
-				offset = (y + clip->y1) * dpitch + (x + clip->x1) * cpp;
-				new_page = offset >> PAGE_SHIFT;
-				offset = offset % PAGE_SIZE;
-				if (new_page != page) {
-					if (!pages[new_page])
-						continue;
-					if (vaddr)
-						kunmap_local(vaddr);
-					page = new_page;
-					vaddr = kmap_local_page_try_from_panic(pages[page]);
-				}
-				if (!vaddr)
-					continue;
-
-				// Special case for 24bit, as a pixel might cross page boundaries
-				if (cpp == 3 && offset + 3 > PAGE_SIZE)
-					drm_panic_write_pixel24_xpage(vaddr, pages[page + 1],
-								      offset, fg32);
-				else
-					drm_panic_write_pixel(vaddr, offset, fg32, cpp);
-			}
-		}
-	}
-	if (vaddr)
-		kunmap_local(vaddr);
-}
-
-/*
- * drm_panic_blit - convert a monochrome image to a linear framebuffer
- * @sb: destination scanout buffer
- * @clip: destination rectangle
- * @sbuf8: source buffer, in monochrome format, 8 pixels per byte.
- * @spitch: source pitch in bytes
- * @scale: integer scale, source buffer is scale time smaller than destination
- *         rectangle
- * @fg_color: foreground color, in destination format
- *
- * This can be used to draw a font character, which is a monochrome image, to a
- * framebuffer in other supported format.
- */
-static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
-			   const u8 *sbuf8, unsigned int spitch,
-			   unsigned int scale, u32 fg_color)
-
-{
-	struct iosys_map map;
-
-	if (sb->set_pixel)
-		return drm_panic_blit_pixel(sb, clip, sbuf8, spitch, scale, fg_color);
-
-	if (sb->pages)
-		return drm_panic_blit_page(sb->pages, sb->pitch[0], sb->format->cpp[0],
-					   sbuf8, spitch, clip, scale, fg_color);
-
-	map = sb->map[0];
-	iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);
-
-	switch (sb->format->cpp[0]) {
-	case 2:
-		drm_draw_blit16(&map, sb->pitch[0], sbuf8, spitch,
-				drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
-	break;
-	case 3:
-		drm_draw_blit24(&map, sb->pitch[0], sbuf8, spitch,
-				drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
-	break;
-	case 4:
-		drm_draw_blit32(&map, sb->pitch[0], sbuf8, spitch,
-				drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
-	break;
-	default:
-		WARN_ONCE(1, "Can't blit with pixel width %d\n", sb->format->cpp[0]);
-	}
-}
-
-static void drm_panic_fill_pixel(struct drm_scanout_buffer *sb,
-				 struct drm_rect *clip,
-				 u32 color)
-{
-	unsigned int y, x;
-
-	for (y = 0; y < drm_rect_height(clip); y++)
-		for (x = 0; x < drm_rect_width(clip); x++)
-			sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, color);
-}
-
-static void drm_panic_fill_page(struct page **pages, unsigned int dpitch,
-				unsigned int cpp, struct drm_rect *clip,
-				u32 color)
-{
-	unsigned int y, x;
-	unsigned int page = ~0;
-	void *vaddr = NULL;
-
-	for (y = clip->y1; y < clip->y2; y++) {
-		for (x = clip->x1; x < clip->x2; x++) {
-			unsigned int new_page;
-			unsigned int offset;
-
-			offset = y * dpitch + x * cpp;
-			new_page = offset >> PAGE_SHIFT;
-			offset = offset % PAGE_SIZE;
-			if (new_page != page) {
-				if (vaddr)
-					kunmap_local(vaddr);
-				page = new_page;
-				vaddr = kmap_local_page_try_from_panic(pages[page]);
-			}
-			if (!vaddr)
-				continue;
-
-			// Special case for 24bit, as a pixel might cross page boundaries
-			if (cpp == 3 && offset + 3 > PAGE_SIZE)
-				drm_panic_write_pixel24_xpage(vaddr, pages[page + 1],
-							      offset, color);
-			else
-				drm_panic_write_pixel(vaddr, offset, color, cpp);
-		}
-	}
-	if (vaddr)
-		kunmap_local(vaddr);
-}
-
-/*
- * drm_panic_fill - Fill a rectangle with a color
- * @sb: destination scanout buffer
- * @clip: destination rectangle
- * @color: foreground color, in destination format
- *
- * Fill a rectangle with a color, in a linear framebuffer.
- */
-static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip,
-			   u32 color)
-{
-	struct iosys_map map;
-
-	if (sb->set_pixel)
-		return drm_panic_fill_pixel(sb, clip, color);
-
-	if (sb->pages)
-		return drm_panic_fill_page(sb->pages, sb->pitch[0], sb->format->cpp[0],
-					   clip, color);
-
-	map = sb->map[0];
-	iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);
-
-	switch (sb->format->cpp[0]) {
-	case 2:
-		drm_draw_fill16(&map, sb->pitch[0], drm_rect_height(clip),
-				drm_rect_width(clip), color);
-	break;
-	case 3:
-		drm_draw_fill24(&map, sb->pitch[0], drm_rect_height(clip),
-				drm_rect_width(clip), color);
-	break;
-	case 4:
-		drm_draw_fill32(&map, sb->pitch[0], drm_rect_height(clip),
-				drm_rect_width(clip), color);
-	break;
-	default:
-		WARN_ONCE(1, "Can't fill with pixel width %d\n", sb->format->cpp[0]);
-	}
-}
-
-static unsigned int get_max_line_len(const struct drm_panic_line *lines, int len)
-{
-	int i;
-	unsigned int max = 0;
-
-	for (i = 0; i < len; i++)
-		max = max(lines[i].len, max);
-	return max;
-}
-
-/*
- * Draw a text in a rectangle on a framebuffer. The text is truncated if it overflows the rectangle
- */
-static void draw_txt_rectangle(struct drm_scanout_buffer *sb,
-			       const struct font_desc *font,
-			       const struct drm_panic_line *msg,
-			       unsigned int msg_lines,
-			       bool centered,
-			       struct drm_rect *clip,
-			       u32 color)
-{
-	int i, j;
-	const u8 *src;
-	size_t font_pitch = DIV_ROUND_UP(font->width, 8);
-	struct drm_rect rec;
-
-	msg_lines = min(msg_lines,  drm_rect_height(clip) / font->height);
-	for (i = 0; i < msg_lines; i++) {
-		size_t line_len = min(msg[i].len, drm_rect_width(clip) / font->width);
-
-		rec.y1 = clip->y1 +  i * font->height;
-		rec.y2 = rec.y1 + font->height;
-		rec.x1 = clip->x1;
-
-		if (centered)
-			rec.x1 += (drm_rect_width(clip) - (line_len * font->width)) / 2;
-
-		for (j = 0; j < line_len; j++) {
-			src = font_data_glyph_buf(font->data, font->width, font->height,
-						  (unsigned char)msg[i].txt[j]);
-			rec.x2 = rec.x1 + font->width;
-			if (src)
-				drm_panic_blit(sb, &rec, src, font_pitch, 1, color);
-			rec.x1 += font->width;
-		}
-	}
-}
-
-static void drm_panic_logo_rect(struct drm_rect *rect, const struct font_desc *font)
-{
-	if (logo_mono) {
-		drm_rect_init(rect, 0, 0, logo_mono->width, logo_mono->height);
-	} else {
-		int logo_width = get_max_line_len(logo_ascii, logo_ascii_lines) * font->width;
-
-		drm_rect_init(rect, 0, 0, logo_width, logo_ascii_lines * font->height);
-	}
-}
-
-static void drm_panic_logo_draw(struct drm_scanout_buffer *sb, struct drm_rect *rect,
-				const struct font_desc *font, u32 fg_color)
-{
-	if (rect->x2 > sb->width || rect->y2 > sb->height)
-		return;
-
-	if (logo_mono)
-		drm_panic_blit(sb, rect, logo_mono->data,
-			       DIV_ROUND_UP(drm_rect_width(rect), 8), 1, fg_color);
-	else
-		draw_txt_rectangle(sb, font, logo_ascii, logo_ascii_lines, false, rect,
-				   fg_color);
-}
-
-static int draw_panic_screen_user(struct drm_scanout_buffer *sb, u32 fg_color, u32 bg_color)
-{
-	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
-	struct drm_rect r_screen, r_logo, r_msg;
-	unsigned int msg_width, msg_height;
-
-	if (!font)
-		return -EINVAL;
-
-	fg_color = drm_draw_color_from_xrgb8888(fg_color, sb->format->format);
-	bg_color = drm_draw_color_from_xrgb8888(bg_color, sb->format->format);
-
-	r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
-	drm_panic_logo_rect(&r_logo, font);
-
-	msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width);
-	msg_height = min(panic_msg_lines * font->height, sb->height);
-	r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height);
-
-	/* Center the panic message */
-	drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, (sb->height - r_msg.y2) / 2);
-
-	/* Fill with the background color, and draw text on top */
-	drm_panic_fill(sb, &r_screen, bg_color);
-
-	if (!drm_rect_overlap(&r_logo, &r_msg))
-		drm_panic_logo_draw(sb, &r_logo, font, fg_color);
-
-	draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color);
-
-	return 0;
-}
-
-/*
- * Draw one line of kmsg, and handle wrapping if it won't fit in the screen width.
- * Return the y-offset of the next line.
- */
-static int draw_line_with_wrap(struct drm_scanout_buffer *sb, const struct font_desc *font,
-			       struct drm_panic_line *line, int yoffset, u32 fg_color)
-{
-	int chars_per_row = sb->width / font->width;
-	struct drm_rect r_txt = DRM_RECT_INIT(0, yoffset, sb->width, font->height);
-	struct drm_panic_line line_wrap;
-
-	if (line->len > chars_per_row) {
-		line_wrap.len = line->len % chars_per_row;
-		line_wrap.txt = line->txt + line->len - line_wrap.len;
-		draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color);
-		r_txt.y1 -= font->height;
-		if (r_txt.y1 < 0)
-			return r_txt.y1;
-		while (line_wrap.txt > line->txt) {
-			line_wrap.txt -= chars_per_row;
-			line_wrap.len = chars_per_row;
-			draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color);
-			r_txt.y1 -= font->height;
-			if (r_txt.y1 < 0)
-				return r_txt.y1;
-		}
-	} else {
-		draw_txt_rectangle(sb, font, line, 1, false, &r_txt, fg_color);
-		r_txt.y1 -= font->height;
-	}
-	return r_txt.y1;
-}
-
-/*
- * Draw the kmsg buffer to the screen, starting from the youngest message at the bottom,
- * and going up until reaching the top of the screen.
- */
-static int draw_panic_screen_kmsg(struct drm_scanout_buffer *sb, u32 fg_color, u32 bg_color)
-{
-	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
-	struct drm_rect r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
-	struct kmsg_dump_iter iter;
-	char kmsg_buf[512];
-	size_t kmsg_len;
-	struct drm_panic_line line;
-	int yoffset;
-
-	if (!font || font->width > sb->width)
-		return -EINVAL;
-
-	fg_color = drm_draw_color_from_xrgb8888(fg_color, sb->format->format);
-	bg_color = drm_draw_color_from_xrgb8888(bg_color, sb->format->format);
-
-	yoffset = sb->height - font->height - (sb->height % font->height) / 2;
-
-	/* Fill with the background color, and draw text on top */
-	drm_panic_fill(sb, &r_screen, bg_color);
-
-	kmsg_dump_rewind(&iter);
-	while (kmsg_dump_get_buffer(&iter, false, kmsg_buf, sizeof(kmsg_buf), &kmsg_len)) {
-		char *start;
-		char *end;
-
-		/* ignore terminating NUL and newline */
-		start = kmsg_buf + kmsg_len - 2;
-		end = kmsg_buf + kmsg_len - 1;
-		while (start > kmsg_buf && yoffset >= 0) {
-			while (start > kmsg_buf && *start != '\n')
-				start--;
-			/* don't count the newline character */
-			line.txt = start + (start == kmsg_buf ? 0 : 1);
-			line.len = end - line.txt;
-
-			yoffset = draw_line_with_wrap(sb, font, &line, yoffset, fg_color);
-			end = start;
-			start--;
-		}
-	}
-
-	return 0;
-}
-
 #if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
-/*
- * It is unwise to allocate memory in the panic callback, so the buffers are
- * pre-allocated. Only 2 buffers and the zlib workspace are needed.
- * Two buffers are enough, using the following buffer usage:
- * 1) kmsg messages are dumped in buffer1
- * 2) kmsg is zlib-compressed into buffer2
- * 3) compressed kmsg is encoded as QR-code Numeric stream in buffer1
- * 4) QR-code image is generated in buffer2
- * The Max QR code size is V40, 177x177, 4071 bytes for image, 2956 bytes for
- * data segments.
- *
- * Typically, ~7500 bytes of kmsg, are compressed into 2800 bytes, which fits in
- * a V40 QR-code (177x177).
- *
- * If CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL is not set, the kmsg data will be put
- * directly in the QR code.
- * 1) kmsg messages are dumped in buffer1
- * 2) kmsg message is encoded as byte stream in buffer2
- * 3) QR-code image is generated in buffer1
- */
-
 static uint panic_qr_version = CONFIG_DRM_PANIC_SCREEN_QR_VERSION;
 module_param(panic_qr_version, uint, 0644);
 MODULE_PARM_DESC(panic_qr_version, "maximum version (size) of the QR code");
-
-#define MAX_QR_DATA 2956
-#define MAX_ZLIB_RATIO 3
-#define QR_BUFFER1_SIZE (MAX_ZLIB_RATIO * MAX_QR_DATA) /* Must also be > 4071  */
-#define QR_BUFFER2_SIZE 4096
-#define QR_MARGIN	4	/* 4 modules of foreground color around the qr code */
-
-/* Compression parameters */
-#define COMPR_LEVEL 6
-#define WINDOW_BITS 12
-#define MEM_LEVEL 4
-
-static u8 qrbuf1[QR_BUFFER1_SIZE];
-static u8 qrbuf2[QR_BUFFER2_SIZE];
-static struct z_stream_s stream;
-
-static void __init drm_panic_qr_init(void)
-{
-	int wssize;
-
-	wssize = zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL);
-	if (WARN_ON_ONCE(wssize < 0))
-		return;
-	/* best-effort allocation; can be NULL */
-	stream.workspace = kmalloc(wssize, GFP_KERNEL);
-
-	/* touch memory so that pages are there in the case of a panic */
-	memset(qrbuf1, 0, sizeof(qrbuf1));
-	memset(qrbuf2, 0, sizeof(qrbuf2));
-	if (stream.workspace)
-		memset(stream.workspace, 0, wssize);
-}
-
-static void drm_panic_qr_exit(void)
-{
-	kfree(stream.workspace);
-	stream.workspace = NULL;
-}
-
-static int drm_panic_get_qr_code_url(u8 **qr_image, unsigned int qr_version)
-{
-	struct kmsg_dump_iter iter;
-	char url[256];
-	size_t kmsg_len, max_kmsg_size;
-	char *kmsg;
-	int ret;
-	size_t max_qr_data_size, url_len;
-
-	ret = snprintf(url, sizeof(url), CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL "?a=%s&v=%s&z=",
-		       utsname()->machine, utsname()->release);
-	if (ret >= sizeof(url))
-		return -EINVAL;
-	url_len = ret;
-
-	max_qr_data_size = drm_panic_qr_max_data_size(qr_version, url_len);
-	max_kmsg_size = min(MAX_ZLIB_RATIO * max_qr_data_size, sizeof(qrbuf1));
-
-	/* get kmsg to buffer 1 */
-	kmsg_dump_rewind(&iter);
-	kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len);
-
-	if (!kmsg_len)
-		return -ENODATA;
-	kmsg = qrbuf1;
-
-try_again:
-	if (zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
-			      MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK)
-		return -EINVAL;
-
-	stream.next_in = kmsg;
-	stream.avail_in = kmsg_len;
-	stream.total_in = 0;
-	stream.next_out = qrbuf2;
-	stream.avail_out = sizeof(qrbuf2);
-	stream.total_out = 0;
-
-	if (zlib_deflate(&stream, Z_FINISH) != Z_STREAM_END)
-		return -EINVAL;
-
-	if (zlib_deflateEnd(&stream) != Z_OK)
-		return -EINVAL;
-
-	if (stream.total_out > max_qr_data_size) {
-		/* too much data for the QR code, so skip the first line and try again */
-		kmsg = strchr(kmsg, '\n');
-		if (!kmsg)
-			return -EINVAL;
-		/* skip the first \n */
-		kmsg += 1;
-		kmsg_len = strlen(kmsg);
-		goto try_again;
-	}
-	*qr_image = qrbuf2;
-
-	/* generate qr code image in buffer2 */
-	return drm_panic_qr_generate(url, qrbuf2, stream.total_out, sizeof(qrbuf2),
-				     qrbuf1, sizeof(qrbuf1));
-}
-
-static int drm_panic_get_qr_code_raw(u8 **qr_image, unsigned int qr_version)
-{
-	struct kmsg_dump_iter iter;
-	size_t kmsg_len;
-	size_t max_kmsg_size = min(drm_panic_qr_max_data_size(qr_version, 0),
-				   sizeof(qrbuf1));
-
-	kmsg_dump_rewind(&iter);
-	kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len);
-	if (!kmsg_len)
-		return -ENODATA;
-
-	*qr_image = qrbuf1;
-	return drm_panic_qr_generate(NULL, qrbuf1, kmsg_len, sizeof(qrbuf1),
-				     qrbuf2, sizeof(qrbuf2));
-}
-
-static int drm_panic_get_qr_code(u8 **qr_image, unsigned int qr_version)
-{
-	if (strlen(CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL) > 0)
-		return drm_panic_get_qr_code_url(qr_image, qr_version);
-	else
-		return drm_panic_get_qr_code_raw(qr_image, qr_version);
-}
-
-/*
- * Draw the panic message at the center of the screen, with a QR Code
- */
-static int draw_panic_screen_qr_code(struct drm_scanout_buffer *sb,
-				     u32 fg_color, u32 bg_color,
-				     unsigned int qr_version)
-{
-	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
-	struct drm_rect r_screen, r_logo, r_msg, r_qr, r_qr_canvas;
-	unsigned int max_qr_size, scale;
-	unsigned int msg_width, msg_height;
-	int qr_width, qr_canvas_width, qr_pitch, v_margin;
-	u8 *qr_image;
-
-	if (!stream.workspace)
-		return -ENOMEM;
-	if (!font)
-		return -EINVAL;
-
-	fg_color = drm_draw_color_from_xrgb8888(fg_color, sb->format->format);
-	bg_color = drm_draw_color_from_xrgb8888(bg_color, sb->format->format);
-
-	r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
-
-	drm_panic_logo_rect(&r_logo, font);
-
-	msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width);
-	msg_height = min(panic_msg_lines * font->height, sb->height);
-	r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height);
-
-	max_qr_size = min(3 * sb->width / 4, 3 * sb->height / 4);
-
-	qr_width = drm_panic_get_qr_code(&qr_image, qr_version);
-	if (qr_width <= 0)
-		return -ENOSPC;
-
-	qr_canvas_width = qr_width + QR_MARGIN * 2;
-	scale = max_qr_size / qr_canvas_width;
-	/* QR code is not readable if not scaled at least by 2 */
-	if (scale < 2)
-		return -ENOSPC;
-
-	pr_debug("QR width %d and scale %d\n", qr_width, scale);
-	r_qr_canvas = DRM_RECT_INIT(0, 0, qr_canvas_width * scale, qr_canvas_width * scale);
-
-	v_margin = sb->height - drm_rect_height(&r_qr_canvas) - drm_rect_height(&r_msg);
-	if (v_margin < 0)
-		return -ENOSPC;
-	v_margin /= 5;
-
-	drm_rect_translate(&r_qr_canvas, (sb->width - r_qr_canvas.x2) / 2, 2 * v_margin);
-	r_qr = DRM_RECT_INIT(r_qr_canvas.x1 + QR_MARGIN * scale, r_qr_canvas.y1 + QR_MARGIN * scale,
-			     qr_width * scale, qr_width * scale);
-
-	/* Center the panic message */
-	drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2,
-			   3 * v_margin + drm_rect_height(&r_qr_canvas));
-
-	/* Fill with the background color, and draw text on top */
-	drm_panic_fill(sb, &r_screen, bg_color);
-
-	if (!drm_rect_overlap(&r_logo, &r_msg) && !drm_rect_overlap(&r_logo, &r_qr_canvas))
-		drm_panic_logo_draw(sb, &r_logo, font, fg_color);
-
-	draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color);
-
-	/* Draw the qr code */
-	qr_pitch = DIV_ROUND_UP(qr_width, 8);
-	drm_panic_fill(sb, &r_qr_canvas, fg_color);
-	drm_panic_fill(sb, &r_qr, bg_color);
-	drm_panic_blit(sb, &r_qr, qr_image, qr_pitch, scale, fg_color);
-	return 0;
-}
-#else
-static void drm_panic_qr_init(void) {};
-static void drm_panic_qr_exit(void) {};
 #endif
 
 static enum drm_panic_type drm_panic_type = -1;
@@ -853,127 +96,6 @@ MODULE_PARM_DESC(panic_screen,
 #endif
 		 CONFIG_DRM_PANIC_SCREEN "]");
 
-/*
- * drm_panic_is_format_supported()
- * @format: a fourcc color code
- * Returns: true if supported, false otherwise.
- *
- * Check if drm_panic will be able to use this color format.
- */
-static bool drm_panic_is_format_supported(const struct drm_format_info *format)
-{
-	if (format->num_planes != 1)
-		return false;
-	return drm_draw_can_convert_from_xrgb8888(format->format);
-}
-
-static int draw_panic_dispatch(struct drm_scanout_buffer *sb, enum drm_panic_type panic_type,
-			       u32 fg_color, u32 bg_color, unsigned int qr_version)
-{
-	int ret;
-
-retry:
-	switch (panic_type) {
-	case DRM_PANIC_TYPE_KMSG:
-		ret = draw_panic_screen_kmsg(sb, fg_color, bg_color);
-		if (ret) {
-			panic_type = DRM_PANIC_TYPE_USER;
-			goto retry;
-		}
-		break;
-#if IS_ENABLED(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
-	case DRM_PANIC_TYPE_QR:
-		ret = draw_panic_screen_qr_code(sb, fg_color, bg_color, qr_version);
-		if (ret) {
-			panic_type = DRM_PANIC_TYPE_USER;
-			goto retry;
-		}
-		break;
-#endif
-	case DRM_PANIC_TYPE_USER:
-	default:
-		ret = draw_panic_screen_user(sb, fg_color, bg_color);
-	}
-
-	return ret;
-}
-
-static void drm_panic_set_description(const char *description)
-{
-	u32 len;
-
-	if (description) {
-		struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1];
-
-		desc_line->txt = description;
-		len = strlen(description);
-		/* ignore the last newline character */
-		if (len && description[len - 1] == '\n')
-			len -= 1;
-		desc_line->len = len;
-	}
-}
-
-static void drm_panic_clear_description(void)
-{
-	struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1];
-
-	desc_line->len = 0;
-	desc_line->txt = NULL;
-}
-
-/**
- * drm_plane_helper_display_panic_screen - Displays a panic screen according to the given settings
- * @plane: the DRM plane to display to
- * @description: error message to display
- * @panic_type: type of panic screen
- * @fg_color: text foreground color
- * @bg_color: text background color
- * @qr_version: version of the QR code, if any
- *
- * This helper display a panic screen on common primary planes. The panic
- * screen can either display a kernel message, a user message or a QR code.
- *
- * The helper uses struct drm_plane_helper_funcs.get_scanout_buffer, where
- * the plane can provide a scanout buffer that the panic handler can draw to.
- * Currently only linear buffer and a few color formats are supported.
- *
- * Optionally the plane can also provide a &drm_plane_helper_funcs.panic_flush
- * callback, which the DRM panic handler calls after drawing to send additional
- * commands to the hardware to make the scanout buffer visible.
- */
-void drm_plane_helper_display_panic_screen(struct drm_plane *plane, const char *description,
-					   enum drm_panic_type panic_type,
-					   u32 fg_color, u32 bg_color, unsigned int qr_version)
-{
-	struct drm_scanout_buffer sb = { };
-	int ret;
-
-	ret = plane->helper_private->get_scanout_buffer(plane, &sb);
-
-	if (ret || !drm_panic_is_format_supported(sb.format))
-		return;
-
-	/* One of these should be set, or it can't draw pixels */
-	if (!sb.set_pixel && !sb.pages && iosys_map_is_null(&sb.map[0]))
-		return;
-
-	drm_panic_set_description(description);
-
-	ret = draw_panic_dispatch(&sb, drm_panic_type, fg_color, bg_color, qr_version);
-	if (!ret) {
-		/*
-		 * Only flush if we have a panic screen to display. Otherwise
-		 * it's probably better to leave the display output as-is.
-		 */
-		if (plane->helper_private->panic_flush)
-			plane->helper_private->panic_flush(plane);
-	}
-
-	drm_panic_clear_description();
-}
-EXPORT_SYMBOL(drm_plane_helper_display_panic_screen);
-
 #define drm_panic_trylock(dev, flags) \
 	raw_spin_trylock_irqsave(&(dev)->mode_config.panic_lock, flags)
 
@@ -1132,17 +254,4 @@ void __init drm_panic_init(void)
 			CONFIG_DRM_PANIC_SCREEN);
 		drm_panic_type = DRM_PANIC_TYPE_USER;
 	}
-	drm_panic_qr_init();
-}
-
-/**
- * drm_panic_exit() - Free the resources taken by drm_panic_exit()
- */
-void drm_panic_exit(void)
-{
-	drm_panic_qr_exit();
 }
-
-#ifdef CONFIG_DRM_KUNIT_TEST
-#include "tests/drm_panic_test.c"
-#endif
diff --git a/drivers/gpu/drm/drm_panic_helper.c b/drivers/gpu/drm/drm_panic_helper.c
new file mode 100644
index 000000000000..3d612f9f3a37
--- /dev/null
+++ b/drivers/gpu/drm/drm_panic_helper.c
@@ -0,0 +1,913 @@
+// SPDX-License-Identifier: GPL-2.0 or MIT
+
+#include <linux/export.h>
+#include <linux/font.h>
+#include <linux/highmem.h>
+#include <linux/iosys-map.h>
+#include <linux/linux_logo.h>
+#include <linux/utsname.h>
+#include <linux/zlib.h>
+
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_panic.h>
+#include <drm/drm_panic_helper.h>
+#include <drm/drm_plane.h>
+#include <drm/drm_rect.h>
+
+#include "drm_draw_internal.h"
+#include "drm_panic_internal.h"
+
+struct drm_panic_line {
+	u32 len;
+	const char *txt;
+};
+
+#define PANIC_LINE(s) {.len = sizeof(s) - 1, .txt = s}
+
+static struct drm_panic_line panic_msg[] = {
+	PANIC_LINE("KERNEL PANIC!"),
+	PANIC_LINE(""),
+	PANIC_LINE("Please reboot your computer."),
+	PANIC_LINE(""),
+	PANIC_LINE(""), /* will be replaced by the panic description */
+};
+
+static const size_t panic_msg_lines = ARRAY_SIZE(panic_msg);
+
+static const struct drm_panic_line logo_ascii[] = {
+	PANIC_LINE("     .--.        _"),
+	PANIC_LINE("    |o_o |      | |"),
+	PANIC_LINE("    |:_/ |      | |"),
+	PANIC_LINE("   //   \\ \\     |_|"),
+	PANIC_LINE("  (|     | )     _"),
+	PANIC_LINE(" /'\\_   _/`\\    (_)"),
+	PANIC_LINE(" \\___)=(___/"),
+};
+
+static const size_t logo_ascii_lines = ARRAY_SIZE(logo_ascii);
+
+#if defined(CONFIG_LOGO) && !defined(MODULE)
+static const struct linux_logo *logo_mono;
+
+static int __init drm_panic_helper_setup_logo(void)
+{
+	const struct linux_logo *logo = fb_find_logo(1);
+	const unsigned char *logo_data;
+	struct linux_logo *logo_dup;
+
+	if (!logo || logo->type != LINUX_LOGO_MONO)
+		return 0;
+
+	/* The logo is __init, so we must make a copy for later use */
+	logo_data = kmemdup(logo->data,
+			    size_mul(DIV_ROUND_UP(logo->width, BITS_PER_BYTE), logo->height),
+			    GFP_KERNEL);
+	if (!logo_data)
+		return -ENOMEM;
+
+	logo_dup = kmemdup(logo, sizeof(*logo), GFP_KERNEL);
+	if (!logo_dup) {
+		kfree(logo_data);
+		return -ENOMEM;
+	}
+
+	logo_dup->data = logo_data;
+	logo_mono = logo_dup;
+
+	return 0;
+}
+#else
+#define logo_mono	((const struct linux_logo *)NULL)
+static int __init drm_panic_helper_setup_logo(void)
+{
+	return 0;
+}
+#endif
+
+/*
+ *  Blit & Fill functions
+ */
+static void drm_panic_helper_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip,
+					const u8 *sbuf8, unsigned int spitch, unsigned int scale,
+					u32 fg_color)
+{
+	unsigned int y, x;
+
+	for (y = 0; y < drm_rect_height(clip); y++)
+		for (x = 0; x < drm_rect_width(clip); x++)
+			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
+				sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color);
+}
+
+static void drm_panic_helper_write_pixel16(void *vaddr, unsigned int offset, u16 color)
+{
+	u16 *p = vaddr + offset;
+
+	*p = color;
+}
+
+static void drm_panic_helper_write_pixel24(void *vaddr, unsigned int offset, u32 color)
+{
+	u8 *p = vaddr + offset;
+
+	*p++ = color & 0xff;
+	color >>= 8;
+	*p++ = color & 0xff;
+	color >>= 8;
+	*p = color & 0xff;
+}
+
+/*
+ * Special case if the pixel crosses page boundaries
+ */
+static void drm_panic_helper_write_pixel24_xpage(void *vaddr, struct page *next_page,
+						 unsigned int offset, u32 color)
+{
+	u8 *vaddr2;
+	u8 *p = vaddr + offset;
+
+	vaddr2 = kmap_local_page_try_from_panic(next_page);
+
+	*p++ = color & 0xff;
+	color >>= 8;
+
+	if (offset == PAGE_SIZE - 1)
+		p = vaddr2;
+
+	*p++ = color & 0xff;
+	color >>= 8;
+
+	if (offset == PAGE_SIZE - 2)
+		p = vaddr2;
+
+	*p = color & 0xff;
+	kunmap_local(vaddr2);
+}
+
+static void drm_panic_helper_write_pixel32(void *vaddr, unsigned int offset, u32 color)
+{
+	u32 *p = vaddr + offset;
+
+	*p = color;
+}
+
+static void drm_panic_helper_write_pixel(void *vaddr, unsigned int offset, u32 color,
+					 unsigned int cpp)
+{
+	switch (cpp) {
+	case 2:
+		drm_panic_helper_write_pixel16(vaddr, offset, color);
+		break;
+	case 3:
+		drm_panic_helper_write_pixel24(vaddr, offset, color);
+		break;
+	case 4:
+		drm_panic_helper_write_pixel32(vaddr, offset, color);
+		break;
+	default:
+		pr_debug_once("Can't blit with pixel width %d\n", cpp);
+	}
+}
+
+/*
+ * 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 drm_panic_helper_blit_page(struct page **pages, unsigned int dpitch,
+				       unsigned int cpp, const u8 *sbuf8,
+				       unsigned int spitch, struct drm_rect *clip,
+				       unsigned int scale, u32 fg32)
+{
+	unsigned int y, x;
+	unsigned int page = ~0;
+	unsigned int height = drm_rect_height(clip);
+	unsigned int width = drm_rect_width(clip);
+	void *vaddr = NULL;
+
+	for (y = 0; y < height; y++) {
+		for (x = 0; x < width; x++) {
+			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) {
+				unsigned int new_page;
+				unsigned int offset;
+
+				offset = (y + clip->y1) * dpitch + (x + clip->x1) * cpp;
+				new_page = offset >> PAGE_SHIFT;
+				offset = offset % PAGE_SIZE;
+				if (new_page != page) {
+					if (!pages[new_page])
+						continue;
+					if (vaddr)
+						kunmap_local(vaddr);
+					page = new_page;
+					vaddr = kmap_local_page_try_from_panic(pages[page]);
+				}
+				if (!vaddr)
+					continue;
+
+				// Special case for 24bit, as a pixel might cross page boundaries
+				if (cpp == 3 && offset + 3 > PAGE_SIZE)
+					drm_panic_helper_write_pixel24_xpage(vaddr,
+									     pages[page + 1],
+									     offset, fg32);
+				else
+					drm_panic_helper_write_pixel(vaddr, offset, fg32, cpp);
+			}
+		}
+	}
+	if (vaddr)
+		kunmap_local(vaddr);
+}
+
+/*
+ * drm_panic_helper_blit - convert a monochrome image to a linear framebuffer
+ * @sb: destination scanout buffer
+ * @clip: destination rectangle
+ * @sbuf8: source buffer, in monochrome format, 8 pixels per byte.
+ * @spitch: source pitch in bytes
+ * @scale: integer scale, source buffer is scale time smaller than destination
+ *         rectangle
+ * @fg_color: foreground color, in destination format
+ *
+ * This can be used to draw a font character, which is a monochrome image, to a
+ * framebuffer in other supported format.
+ */
+static void drm_panic_helper_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
+				  const u8 *sbuf8, unsigned int spitch,
+				  unsigned int scale, u32 fg_color)
+
+{
+	struct iosys_map map;
+
+	if (sb->set_pixel)
+		return drm_panic_helper_blit_pixel(sb, clip, sbuf8, spitch, scale, fg_color);
+
+	if (sb->pages)
+		return drm_panic_helper_blit_page(sb->pages, sb->pitch[0], sb->format->cpp[0],
+						  sbuf8, spitch, clip, scale, fg_color);
+
+	map = sb->map[0];
+	iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);
+
+	switch (sb->format->cpp[0]) {
+	case 2:
+		drm_draw_blit16(&map, sb->pitch[0], sbuf8, spitch,
+				drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
+	break;
+	case 3:
+		drm_draw_blit24(&map, sb->pitch[0], sbuf8, spitch,
+				drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
+	break;
+	case 4:
+		drm_draw_blit32(&map, sb->pitch[0], sbuf8, spitch,
+				drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
+	break;
+	default:
+		WARN_ONCE(1, "Can't blit with pixel width %d\n", sb->format->cpp[0]);
+	}
+}
+
+static void drm_panic_helper_fill_pixel(struct drm_scanout_buffer *sb,
+					struct drm_rect *clip,
+					u32 color)
+{
+	unsigned int y, x;
+
+	for (y = 0; y < drm_rect_height(clip); y++)
+		for (x = 0; x < drm_rect_width(clip); x++)
+			sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, color);
+}
+
+static void drm_panic_helper_fill_page(struct page **pages, unsigned int dpitch,
+				       unsigned int cpp, struct drm_rect *clip,
+				       u32 color)
+{
+	unsigned int y, x;
+	unsigned int page = ~0;
+	void *vaddr = NULL;
+
+	for (y = clip->y1; y < clip->y2; y++) {
+		for (x = clip->x1; x < clip->x2; x++) {
+			unsigned int new_page;
+			unsigned int offset;
+
+			offset = y * dpitch + x * cpp;
+			new_page = offset >> PAGE_SHIFT;
+			offset = offset % PAGE_SIZE;
+			if (new_page != page) {
+				if (vaddr)
+					kunmap_local(vaddr);
+				page = new_page;
+				vaddr = kmap_local_page_try_from_panic(pages[page]);
+			}
+			if (!vaddr)
+				continue;
+
+			// Special case for 24bit, as a pixel might cross page boundaries
+			if (cpp == 3 && offset + 3 > PAGE_SIZE)
+				drm_panic_helper_write_pixel24_xpage(vaddr, pages[page + 1],
+								     offset, color);
+			else
+				drm_panic_helper_write_pixel(vaddr, offset, color, cpp);
+		}
+	}
+	if (vaddr)
+		kunmap_local(vaddr);
+}
+
+/*
+ * drm_panic_helper_fill - Fill a rectangle with a color
+ * @sb: destination scanout buffer
+ * @clip: destination rectangle
+ * @color: foreground color, in destination format
+ *
+ * Fill a rectangle with a color, in a linear framebuffer.
+ */
+static void drm_panic_helper_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip,
+				  u32 color)
+{
+	struct iosys_map map;
+
+	if (sb->set_pixel)
+		return drm_panic_helper_fill_pixel(sb, clip, color);
+
+	if (sb->pages)
+		return drm_panic_helper_fill_page(sb->pages, sb->pitch[0], sb->format->cpp[0],
+						  clip, color);
+
+	map = sb->map[0];
+	iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);
+
+	switch (sb->format->cpp[0]) {
+	case 2:
+		drm_draw_fill16(&map, sb->pitch[0], drm_rect_height(clip),
+				drm_rect_width(clip), color);
+	break;
+	case 3:
+		drm_draw_fill24(&map, sb->pitch[0], drm_rect_height(clip),
+				drm_rect_width(clip), color);
+	break;
+	case 4:
+		drm_draw_fill32(&map, sb->pitch[0], drm_rect_height(clip),
+				drm_rect_width(clip), color);
+	break;
+	default:
+		WARN_ONCE(1, "Can't fill with pixel width %d\n", sb->format->cpp[0]);
+	}
+}
+
+static unsigned int get_max_line_len(const struct drm_panic_line *lines, int len)
+{
+	int i;
+	unsigned int max = 0;
+
+	for (i = 0; i < len; i++)
+		max = max(lines[i].len, max);
+	return max;
+}
+
+/*
+ * Draw a text in a rectangle on a framebuffer. The text is truncated if it overflows the rectangle
+ */
+static void draw_txt_rectangle(struct drm_scanout_buffer *sb,
+			       const struct font_desc *font,
+			       const struct drm_panic_line *msg,
+			       unsigned int msg_lines,
+			       bool centered,
+			       struct drm_rect *clip,
+			       u32 color)
+{
+	int i, j;
+	const u8 *src;
+	size_t font_pitch = DIV_ROUND_UP(font->width, 8);
+	struct drm_rect rec;
+
+	msg_lines = min(msg_lines,  drm_rect_height(clip) / font->height);
+	for (i = 0; i < msg_lines; i++) {
+		size_t line_len = min(msg[i].len, drm_rect_width(clip) / font->width);
+
+		rec.y1 = clip->y1 +  i * font->height;
+		rec.y2 = rec.y1 + font->height;
+		rec.x1 = clip->x1;
+
+		if (centered)
+			rec.x1 += (drm_rect_width(clip) - (line_len * font->width)) / 2;
+
+		for (j = 0; j < line_len; j++) {
+			src = font_data_glyph_buf(font->data, font->width, font->height,
+						  (unsigned char)msg[i].txt[j]);
+			rec.x2 = rec.x1 + font->width;
+			if (src)
+				drm_panic_helper_blit(sb, &rec, src, font_pitch, 1, color);
+			rec.x1 += font->width;
+		}
+	}
+}
+
+static void drm_panic_helper_logo_rect(struct drm_rect *rect, const struct font_desc *font)
+{
+	if (logo_mono) {
+		drm_rect_init(rect, 0, 0, logo_mono->width, logo_mono->height);
+	} else {
+		int logo_width = get_max_line_len(logo_ascii, logo_ascii_lines) * font->width;
+
+		drm_rect_init(rect, 0, 0, logo_width, logo_ascii_lines * font->height);
+	}
+}
+
+static void drm_panic_helper_logo_draw(struct drm_scanout_buffer *sb, struct drm_rect *rect,
+				       const struct font_desc *font, u32 fg_color)
+{
+	if (rect->x2 > sb->width || rect->y2 > sb->height)
+		return;
+
+	if (logo_mono)
+		drm_panic_helper_blit(sb, rect, logo_mono->data,
+				      DIV_ROUND_UP(drm_rect_width(rect), 8), 1, fg_color);
+	else
+		draw_txt_rectangle(sb, font, logo_ascii, logo_ascii_lines, false, rect,
+				   fg_color);
+}
+
+static int drm_panic_helper_draw_screen_user(struct drm_scanout_buffer *sb,
+					     u32 fg_color, u32 bg_color)
+{
+	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
+	struct drm_rect r_screen, r_logo, r_msg;
+	unsigned int msg_width, msg_height;
+
+	if (!font)
+		return -EINVAL;
+
+	fg_color = drm_draw_color_from_xrgb8888(fg_color, sb->format->format);
+	bg_color = drm_draw_color_from_xrgb8888(bg_color, sb->format->format);
+
+	r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
+	drm_panic_helper_logo_rect(&r_logo, font);
+
+	msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width);
+	msg_height = min(panic_msg_lines * font->height, sb->height);
+	r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height);
+
+	/* Center the panic message */
+	drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, (sb->height - r_msg.y2) / 2);
+
+	/* Fill with the background color, and draw text on top */
+	drm_panic_helper_fill(sb, &r_screen, bg_color);
+
+	if (!drm_rect_overlap(&r_logo, &r_msg))
+		drm_panic_helper_logo_draw(sb, &r_logo, font, fg_color);
+
+	draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color);
+
+	return 0;
+}
+
+/*
+ * Draw one line of kmsg, and handle wrapping if it won't fit in the screen width.
+ * Return the y-offset of the next line.
+ */
+static int draw_line_with_wrap(struct drm_scanout_buffer *sb, const struct font_desc *font,
+			       struct drm_panic_line *line, int yoffset, u32 fg_color)
+{
+	int chars_per_row = sb->width / font->width;
+	struct drm_rect r_txt = DRM_RECT_INIT(0, yoffset, sb->width, font->height);
+	struct drm_panic_line line_wrap;
+
+	if (line->len > chars_per_row) {
+		line_wrap.len = line->len % chars_per_row;
+		line_wrap.txt = line->txt + line->len - line_wrap.len;
+		draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color);
+		r_txt.y1 -= font->height;
+		if (r_txt.y1 < 0)
+			return r_txt.y1;
+		while (line_wrap.txt > line->txt) {
+			line_wrap.txt -= chars_per_row;
+			line_wrap.len = chars_per_row;
+			draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color);
+			r_txt.y1 -= font->height;
+			if (r_txt.y1 < 0)
+				return r_txt.y1;
+		}
+	} else {
+		draw_txt_rectangle(sb, font, line, 1, false, &r_txt, fg_color);
+		r_txt.y1 -= font->height;
+	}
+	return r_txt.y1;
+}
+
+/*
+ * Draw the kmsg buffer to the screen, starting from the youngest message at the bottom,
+ * and going up until reaching the top of the screen.
+ */
+static int drm_panic_helper_draw_screen_kmsg(struct drm_scanout_buffer *sb,
+					     u32 fg_color, u32 bg_color)
+{
+	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
+	struct drm_rect r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
+	struct kmsg_dump_iter iter;
+	char kmsg_buf[512];
+	size_t kmsg_len;
+	struct drm_panic_line line;
+	int yoffset;
+
+	if (!font || font->width > sb->width)
+		return -EINVAL;
+
+	fg_color = drm_draw_color_from_xrgb8888(fg_color, sb->format->format);
+	bg_color = drm_draw_color_from_xrgb8888(bg_color, sb->format->format);
+
+	yoffset = sb->height - font->height - (sb->height % font->height) / 2;
+
+	/* Fill with the background color, and draw text on top */
+	drm_panic_helper_fill(sb, &r_screen, bg_color);
+
+	kmsg_dump_rewind(&iter);
+	while (kmsg_dump_get_buffer(&iter, false, kmsg_buf, sizeof(kmsg_buf), &kmsg_len)) {
+		char *start;
+		char *end;
+
+		/* ignore terminating NUL and newline */
+		start = kmsg_buf + kmsg_len - 2;
+		end = kmsg_buf + kmsg_len - 1;
+		while (start > kmsg_buf && yoffset >= 0) {
+			while (start > kmsg_buf && *start != '\n')
+				start--;
+			/* don't count the newline character */
+			line.txt = start + (start == kmsg_buf ? 0 : 1);
+			line.len = end - line.txt;
+
+			yoffset = draw_line_with_wrap(sb, font, &line, yoffset, fg_color);
+			end = start;
+			start--;
+		}
+	}
+
+	return 0;
+}
+
+#if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
+/*
+ * It is unwise to allocate memory in the panic callback, so the buffers are
+ * pre-allocated. Only 2 buffers and the zlib workspace are needed.
+ * Two buffers are enough, using the following buffer usage:
+ * 1) kmsg messages are dumped in buffer1
+ * 2) kmsg is zlib-compressed into buffer2
+ * 3) compressed kmsg is encoded as QR-code Numeric stream in buffer1
+ * 4) QR-code image is generated in buffer2
+ * The Max QR code size is V40, 177x177, 4071 bytes for image, 2956 bytes for
+ * data segments.
+ *
+ * Typically, ~7500 bytes of kmsg, are compressed into 2800 bytes, which fits in
+ * a V40 QR-code (177x177).
+ *
+ * If CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL is not set, the kmsg data will be put
+ * directly in the QR code.
+ * 1) kmsg messages are dumped in buffer1
+ * 2) kmsg message is encoded as byte stream in buffer2
+ * 3) QR-code image is generated in buffer1
+ */
+
+#define MAX_QR_DATA 2956
+#define MAX_ZLIB_RATIO 3
+#define QR_BUFFER1_SIZE (MAX_ZLIB_RATIO * MAX_QR_DATA) /* Must also be > 4071  */
+#define QR_BUFFER2_SIZE 4096
+#define QR_MARGIN	4	/* 4 modules of foreground color around the qr code */
+
+/* Compression parameters */
+#define COMPR_LEVEL 6
+#define WINDOW_BITS 12
+#define MEM_LEVEL 4
+
+static u8 qrbuf1[QR_BUFFER1_SIZE];
+static u8 qrbuf2[QR_BUFFER2_SIZE];
+static struct z_stream_s stream;
+
+static void __init drm_panic_helper_qr_init(void)
+{
+	int wssize;
+
+	wssize = zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL);
+	if (WARN_ON_ONCE(wssize < 0))
+		return;
+	/* best-effort allocation; can be NULL */
+	stream.workspace = kmalloc(wssize, GFP_KERNEL);
+
+	/* touch memory so that pages are there in the case of a panic */
+	memset(qrbuf1, 0, sizeof(qrbuf1));
+	memset(qrbuf2, 0, sizeof(qrbuf2));
+	if (stream.workspace)
+		memset(stream.workspace, 0, wssize);
+}
+
+static void __exit drm_panic_helper_qr_exit(void)
+{
+	kfree(stream.workspace);
+	stream.workspace = NULL;
+}
+
+static int drm_panic_helper_get_qr_code_url(u8 **qr_image, unsigned int qr_version)
+{
+	struct kmsg_dump_iter iter;
+	char url[256];
+	size_t kmsg_len, max_kmsg_size;
+	char *kmsg;
+	int ret;
+	size_t max_qr_data_size, url_len;
+
+	ret = snprintf(url, sizeof(url), CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL "?a=%s&v=%s&z=",
+		       utsname()->machine, utsname()->release);
+	if (ret >= sizeof(url))
+		return -EINVAL;
+	url_len = ret;
+
+	max_qr_data_size = drm_panic_helper_qr_max_data_size(qr_version, url_len);
+	max_kmsg_size = min(MAX_ZLIB_RATIO * max_qr_data_size, sizeof(qrbuf1));
+
+	/* get kmsg to buffer 1 */
+	kmsg_dump_rewind(&iter);
+	kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len);
+
+	if (!kmsg_len)
+		return -ENODATA;
+	kmsg = qrbuf1;
+
+try_again:
+	if (zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
+			      MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK)
+		return -EINVAL;
+
+	stream.next_in = kmsg;
+	stream.avail_in = kmsg_len;
+	stream.total_in = 0;
+	stream.next_out = qrbuf2;
+	stream.avail_out = sizeof(qrbuf2);
+	stream.total_out = 0;
+
+	if (zlib_deflate(&stream, Z_FINISH) != Z_STREAM_END)
+		return -EINVAL;
+
+	if (zlib_deflateEnd(&stream) != Z_OK)
+		return -EINVAL;
+
+	if (stream.total_out > max_qr_data_size) {
+		/* too much data for the QR code, so skip the first line and try again */
+		kmsg = strchr(kmsg, '\n');
+		if (!kmsg)
+			return -EINVAL;
+		/* skip the first \n */
+		kmsg += 1;
+		kmsg_len = strlen(kmsg);
+		goto try_again;
+	}
+	*qr_image = qrbuf2;
+
+	/* generate qr code image in buffer2 */
+	return drm_panic_helper_qr_generate(url, qrbuf2, stream.total_out, ARRAY_SIZE(qrbuf2),
+					    qrbuf1, sizeof(qrbuf1));
+}
+
+static int drm_panic_helper_get_qr_code_raw(u8 **qr_image, unsigned int qr_version)
+{
+	struct kmsg_dump_iter iter;
+	size_t kmsg_len;
+	size_t max_kmsg_size = min(drm_panic_helper_qr_max_data_size(qr_version, 0),
+				   sizeof(qrbuf1));
+
+	kmsg_dump_rewind(&iter);
+	kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len);
+	if (!kmsg_len)
+		return -ENODATA;
+
+	*qr_image = qrbuf1;
+	return drm_panic_helper_qr_generate(NULL, qrbuf1, kmsg_len, sizeof(qrbuf1),
+					    qrbuf2, sizeof(qrbuf2));
+}
+
+static int drm_panic_helper_get_qr_code(u8 **qr_image, unsigned int qr_version)
+{
+	if (strlen(CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL) > 0)
+		return drm_panic_helper_get_qr_code_url(qr_image, qr_version);
+	else
+		return drm_panic_helper_get_qr_code_raw(qr_image, qr_version);
+}
+
+/*
+ * Draw the panic message at the center of the screen, with a QR Code
+ */
+static int drm_panic_helper_draw_screen_qr_code(struct drm_scanout_buffer *sb,
+						u32 fg_color, u32 bg_color,
+						unsigned int qr_version)
+{
+	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
+	struct drm_rect r_screen, r_logo, r_msg, r_qr, r_qr_canvas;
+	unsigned int max_qr_size, scale;
+	unsigned int msg_width, msg_height;
+	int qr_width, qr_canvas_width, qr_pitch, v_margin;
+	u8 *qr_image;
+
+	if (!stream.workspace)
+		return -ENOMEM;
+	if (!font)
+		return -EINVAL;
+
+	fg_color = drm_draw_color_from_xrgb8888(fg_color, sb->format->format);
+	bg_color = drm_draw_color_from_xrgb8888(bg_color, sb->format->format);
+
+	r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
+
+	drm_panic_helper_logo_rect(&r_logo, font);
+
+	msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width);
+	msg_height = min(panic_msg_lines * font->height, sb->height);
+	r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height);
+
+	max_qr_size = min(3 * sb->width / 4, 3 * sb->height / 4);
+
+	qr_width = drm_panic_helper_get_qr_code(&qr_image, qr_version);
+	if (qr_width <= 0)
+		return -ENOSPC;
+
+	qr_canvas_width = qr_width + QR_MARGIN * 2;
+	scale = max_qr_size / qr_canvas_width;
+	/* QR code is not readable if not scaled at least by 2 */
+	if (scale < 2)
+		return -ENOSPC;
+
+	pr_debug("QR width %d and scale %d\n", qr_width, scale);
+	r_qr_canvas = DRM_RECT_INIT(0, 0, qr_canvas_width * scale, qr_canvas_width * scale);
+
+	v_margin = sb->height - drm_rect_height(&r_qr_canvas) - drm_rect_height(&r_msg);
+	if (v_margin < 0)
+		return -ENOSPC;
+	v_margin /= 5;
+
+	drm_rect_translate(&r_qr_canvas, (sb->width - r_qr_canvas.x2) / 2, 2 * v_margin);
+	r_qr = DRM_RECT_INIT(r_qr_canvas.x1 + QR_MARGIN * scale, r_qr_canvas.y1 + QR_MARGIN * scale,
+			     qr_width * scale, qr_width * scale);
+
+	/* Center the panic message */
+	drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2,
+			   3 * v_margin + drm_rect_height(&r_qr_canvas));
+
+	/* Fill with the background color, and draw text on top */
+	drm_panic_helper_fill(sb, &r_screen, bg_color);
+
+	if (!drm_rect_overlap(&r_logo, &r_msg) && !drm_rect_overlap(&r_logo, &r_qr_canvas))
+		drm_panic_helper_logo_draw(sb, &r_logo, font, fg_color);
+
+	draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color);
+
+	/* Draw the qr code */
+	qr_pitch = DIV_ROUND_UP(qr_width, 8);
+	drm_panic_helper_fill(sb, &r_qr_canvas, fg_color);
+	drm_panic_helper_fill(sb, &r_qr, bg_color);
+	drm_panic_helper_blit(sb, &r_qr, qr_image, qr_pitch, scale, fg_color);
+	return 0;
+}
+#else
+static void __init drm_panic_helper_qr_init(void) {};
+static void __exit drm_panic_helper_qr_exit(void) {};
+#endif
+
+/*
+ * drm_panic_helper_format_is_supported()
+ * @format: a fourcc color code
+ * Returns: true if supported, false otherwise.
+ *
+ * Check if drm_panic will be able to use this color format.
+ */
+static bool drm_panic_helper_format_is_supported(const struct drm_format_info *format)
+{
+	if (format->num_planes != 1)
+		return false;
+	return drm_draw_can_convert_from_xrgb8888(format->format);
+}
+
+static int draw_panic_helper_dispatch(struct drm_scanout_buffer *sb,
+				      enum drm_panic_type panic_type,
+				      u32 fg_color, u32 bg_color,
+				      unsigned int qr_version)
+{
+	int ret;
+
+retry:
+	switch (panic_type) {
+	case DRM_PANIC_TYPE_KMSG:
+		ret = drm_panic_helper_draw_screen_kmsg(sb, fg_color, bg_color);
+		if (ret) {
+			panic_type = DRM_PANIC_TYPE_USER;
+			goto retry;
+		}
+		break;
+#if IS_ENABLED(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
+	case DRM_PANIC_TYPE_QR:
+		ret = drm_panic_helper_draw_screen_qr_code(sb, fg_color, bg_color, qr_version);
+		if (ret) {
+			panic_type = DRM_PANIC_TYPE_USER;
+			goto retry;
+		}
+		break;
+#endif
+	case DRM_PANIC_TYPE_USER:
+	default:
+		ret = drm_panic_helper_draw_screen_user(sb, fg_color, bg_color);
+	}
+
+	return ret;
+}
+
+static void drm_panic_helper_set_description(const char *description)
+{
+	u32 len;
+
+	if (description) {
+		struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1];
+
+		desc_line->txt = description;
+		len = strlen(description);
+		/* ignore the last newline character */
+		if (len && description[len - 1] == '\n')
+			len -= 1;
+		desc_line->len = len;
+	}
+}
+
+static void drm_panic_helper_clear_description(void)
+{
+	struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1];
+
+	desc_line->len = 0;
+	desc_line->txt = NULL;
+}
+
+/**
+ * drm_plane_helper_display_panic_screen - Displays a panic screen according to the given settings
+ * @plane: the DRM plane to display to
+ * @description: error message to display
+ * @panic_type: type of panic screen
+ * @fg_color: text foreground color
+ * @bg_color: text background color
+ * @qr_version: version of the QR code, if any
+ *
+ * This helper display a panic screen on common primary planes. The panic
+ * screen can either display a kernel message, a user message or a QR code.
+ *
+ * The helper uses struct drm_plane_helper_funcs.get_scanout_buffer, where
+ * the plane can provide a scanout buffer that the panic handler can draw to.
+ * Currently only linear buffer and a few color formats are supported.
+ *
+ * Optionally the plane can also provide a &drm_plane_helper_funcs.panic_flush
+ * callback, which the DRM panic handler calls after drawing to send additional
+ * commands to the hardware to make the scanout buffer visible.
+ */
+void drm_plane_helper_display_panic_screen(struct drm_plane *plane, const char *description,
+					   enum drm_panic_type panic_type,
+					   u32 fg_color, u32 bg_color, unsigned int qr_version)
+{
+	struct drm_scanout_buffer sb = { };
+	int ret;
+
+	ret = plane->helper_private->get_scanout_buffer(plane, &sb);
+
+	if (ret || !drm_panic_helper_format_is_supported(sb.format))
+		return;
+
+	/* One of these should be set, or it can't draw pixels */
+	if (!sb.set_pixel && !sb.pages && iosys_map_is_null(&sb.map[0]))
+		return;
+
+	drm_panic_helper_set_description(description);
+
+	ret = draw_panic_helper_dispatch(&sb, panic_type, fg_color, bg_color, qr_version);
+	if (!ret) {
+		/*
+		 * Only flush if we have a panic screen to display. Otherwise
+		 * it's probably better to leave the display output as-is.
+		 */
+		if (plane->helper_private->panic_flush)
+			plane->helper_private->panic_flush(plane);
+	}
+
+	drm_panic_helper_clear_description();
+}
+EXPORT_SYMBOL(drm_plane_helper_display_panic_screen);
+
+int __init drm_panic_helper_init(void)
+{
+	drm_panic_helper_setup_logo();
+	drm_panic_helper_qr_init();
+
+	return 0;
+}
+
+void __exit drm_panic_helper_exit(void)
+{
+	drm_panic_helper_qr_exit();
+}
+
+#ifdef CONFIG_DRM_KUNIT_TEST
+#include "tests/drm_panic_helper_test.c"
+#endif
diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_helper_qr.rs
similarity index 99%
rename from drivers/gpu/drm/drm_panic_qr.rs
rename to drivers/gpu/drm/drm_panic_helper_qr.rs
index ac27e86c601c..22966956331e 100644
--- a/drivers/gpu/drm/drm_panic_qr.rs
+++ b/drivers/gpu/drm/drm_panic_helper_qr.rs
@@ -938,7 +938,7 @@ fn draw_all(&mut self, data: impl Iterator<Item = u8>) {
 ///
 /// They must remain valid for the duration of the function call.
 #[export]
-pub unsafe extern "C" fn drm_panic_qr_generate(
+pub unsafe extern "C" fn drm_panic_helper_qr_generate(
     url: *const kernel::ffi::c_char,
     data: *mut u8,
     data_len: usize,
@@ -994,7 +994,7 @@ fn draw_all(&mut self, data: impl Iterator<Item = u8>) {
 /// Always safe to call.
 // Required to be unsafe due to the `#[export]` annotation.
 #[export]
-pub unsafe extern "C" fn drm_panic_qr_max_data_size(version: u8, url_len: usize) -> usize {
+pub unsafe extern "C" fn drm_panic_helper_qr_max_data_size(version: u8, url_len: usize) -> usize {
     #[expect(clippy::manual_range_contains)]
     if version < 1 || version > 40 {
         return 0;
diff --git a/drivers/gpu/drm/drm_panic_internal.h b/drivers/gpu/drm/drm_panic_internal.h
index c68d64c56e15..8aa91e80eb4d 100644
--- a/drivers/gpu/drm/drm_panic_internal.h
+++ b/drivers/gpu/drm/drm_panic_internal.h
@@ -52,4 +52,8 @@ static inline void drm_panic_lock(struct drm_device *dev, unsigned long flags) {
 static inline void drm_panic_unlock(struct drm_device *dev, unsigned long flags) {}
 #endif
 
+/* drm_panic_helper.c */
+int drm_panic_helper_init(void);
+void drm_panic_helper_exit(void);
+
 #endif /* __DRM_PANIC_INTERNAL_H__ */
diff --git a/drivers/gpu/drm/tests/drm_panic_test.c b/drivers/gpu/drm/tests/drm_panic_helper_test.c
similarity index 88%
rename from drivers/gpu/drm/tests/drm_panic_test.c
rename to drivers/gpu/drm/tests/drm_panic_helper_test.c
index 196496238d23..fcff8d2dccbe 100644
--- a/drivers/gpu/drm/tests/drm_panic_test.c
+++ b/drivers/gpu/drm/tests/drm_panic_helper_test.c
@@ -3,7 +3,7 @@
  * Copyright (c) 2025 Red Hat.
  * Author: Jocelyn Falempe <jfalempe@redhat.com>
  *
- * KUNIT tests for drm panic
+ * KUNIT tests for DRM panic helpers
  */
 
 #include <drm/drm_fourcc.h>
@@ -41,24 +41,24 @@ struct drm_test_mode {
 	.width = w, \
 	.height = h, \
 	.format = f, \
-	.draw_screen = draw_panic_screen_ ## name ## _default, \
+	.draw_screen = drm_panic_helper_draw_screen_ ## name ## _default, \
 	.fname = #name, \
 	}, \
 
-static int draw_panic_screen_user_default(struct drm_scanout_buffer *sb)
+static int drm_panic_helper_draw_screen_user_default(struct drm_scanout_buffer *sb)
 {
-	return draw_panic_screen_user(sb, 0x00ffffff, 0x00000000);
+	return drm_panic_helper_draw_screen_user(sb, 0x00ffffff, 0x00000000);
 }
 
-static int draw_panic_screen_kmsg_default(struct drm_scanout_buffer *sb)
+static int drm_panic_helper_draw_screen_kmsg_default(struct drm_scanout_buffer *sb)
 {
-	return draw_panic_screen_kmsg(sb, 0x00ffffff, 0x00000000);
+	return drm_panic_helper_draw_screen_kmsg(sb, 0x00ffffff, 0x00000000);
 }
 
 #if IS_ENABLED(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
-static int draw_panic_screen_qr_code_default(struct drm_scanout_buffer *sb)
+static int drm_panic_helper_draw_screen_qr_code_default(struct drm_scanout_buffer *sb)
 {
-	return draw_panic_screen_qr_code(sb, 0x00ffffff, 0x00000000, 40);
+	return drm_panic_helper_draw_screen_qr_code(sb, 0x00ffffff, 0x00000000, 40);
 }
 #endif
 
@@ -81,7 +81,7 @@ static int drm_test_panic_init(struct kunit *test)
 
 	test->priv = priv;
 
-	drm_panic_set_description("Kunit testing");
+	drm_panic_helper_set_description("Kunit testing");
 
 	return 0;
 }
@@ -226,10 +226,10 @@ static struct kunit_case drm_panic_screen_user_test[] = {
 	{ }
 };
 
-static struct kunit_suite drm_panic_suite = {
-	.name = "drm_panic",
+static struct kunit_suite drm_panic_helper_suite = {
+	.name = "drm_panic_helper",
 	.init = drm_test_panic_init,
 	.test_cases = drm_panic_screen_user_test,
 };
 
-kunit_test_suite(drm_panic_suite);
+kunit_test_suite(drm_panic_helper_suite);
diff --git a/include/drm/drm_panic.h b/include/drm/drm_panic.h
index 99572b7eeab9..3e628cbaffca 100644
--- a/include/drm/drm_panic.h
+++ b/include/drm/drm_panic.h
@@ -85,11 +85,4 @@ struct drm_scanout_buffer {
 	void *private;
 };
 
-#if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
-size_t drm_panic_qr_max_data_size(u8 version, size_t url_len);
-
-u8 drm_panic_qr_generate(const char *url, u8 *data, size_t data_len, size_t data_size,
-			 u8 *tmp, size_t tmp_size);
-#endif
-
 #endif /* __DRM_PANIC_H__ */
diff --git a/include/drm/drm_panic_helper.h b/include/drm/drm_panic_helper.h
index e296620bbe34..6dc63288bc2a 100644
--- a/include/drm/drm_panic_helper.h
+++ b/include/drm/drm_panic_helper.h
@@ -16,6 +16,11 @@ void drm_plane_helper_display_panic_screen(struct drm_plane *plane,
 					   u32 fg_color, u32 bg_color,
 					   unsigned int qr_version);
 
+/* drm_panic_helper_qr.rs */
+size_t drm_panic_helper_qr_max_data_size(u8 version, size_t url_len);
+u8 drm_panic_helper_qr_generate(const char *url, u8 *data, size_t data_len, size_t data_size,
+				u8 *tmp, size_t tmp_size);
+
 #if IS_ENABLED(CONFIG_DRM_PANIC)
 #define DRM_PANIC_PLANE_FUNCS \
 	.display_panic_screen = drm_plane_helper_display_panic_screen
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 1124785e210b..0a11b1f5c4b3 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -102,8 +102,8 @@
 #include <../../drivers/base/base.h>
 
 #if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
-// Used by `#[export]` in `drivers/gpu/drm/drm_panic_qr.rs`.
-#include <drm/drm_panic.h>
+// Used by `#[export]` in `drivers/gpu/drm/drm_panic_helper_qr.rs`.
+#include <drm/drm_panic_helper.h>
 #endif
 
 /* `bindgen` gets confused at certain things. */
-- 
2.55.0