1 files changed, 359 insertions, 47 deletions

diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index 948aed00595e..74412b7bf936 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -18,6 +18,8 @@
 #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>
@@ -26,6 +28,9 @@
 #include <drm/drm_panic.h>
 #include <drm/drm_plane.h>
 #include <drm/drm_print.h>
+#include <drm/drm_rect.h>
+
+#include "drm_crtc_internal.h"
 
 MODULE_AUTHOR("Jocelyn Falempe");
 MODULE_DESCRIPTION("DRM panic handler");
@@ -76,11 +81,15 @@ struct drm_panic_line {
 #define PANIC_LINE(s) {.len = sizeof(s) - 1, .txt = s}
 
 static struct drm_panic_line panic_msg[] = {
-	PANIC_LINE("KERNEL PANIC !"),
+	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 |      | |"),
@@ -91,6 +100,8 @@ static const struct drm_panic_line logo_ascii[] = {
 	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;
 
@@ -249,20 +260,20 @@ static bool drm_panic_is_pixel_fg(const u8 *sbuf8, unsigned int spitch, int x, i
 static void drm_panic_blit16(struct iosys_map *dmap, unsigned int dpitch,
 			     const u8 *sbuf8, unsigned int spitch,
 			     unsigned int height, unsigned int width,
-			     u16 fg16)
+			     unsigned int scale, u16 fg16)
 {
 	unsigned int y, x;
 
 	for (y = 0; y < height; y++)
 		for (x = 0; x < width; x++)
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y))
+			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
 				iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, fg16);
 }
 
 static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,
 			     const u8 *sbuf8, unsigned int spitch,
 			     unsigned int height, unsigned int width,
-			     u32 fg32)
+			     unsigned int scale, u32 fg32)
 {
 	unsigned int y, x;
 
@@ -270,7 +281,7 @@ static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,
 		for (x = 0; x < width; x++) {
 			u32 off = y * dpitch + x * 3;
 
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y)) {
+			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) {
 				/* write blue-green-red to output in little endianness */
 				iosys_map_wr(dmap, off, u8, (fg32 & 0x000000FF) >> 0);
 				iosys_map_wr(dmap, off + 1, u8, (fg32 & 0x0000FF00) >> 8);
@@ -283,24 +294,25 @@ static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,
 static void drm_panic_blit32(struct iosys_map *dmap, unsigned int dpitch,
 			     const u8 *sbuf8, unsigned int spitch,
 			     unsigned int height, unsigned int width,
-			     u32 fg32)
+			     unsigned int scale, u32 fg32)
 {
 	unsigned int y, x;
 
 	for (y = 0; y < height; y++)
 		for (x = 0; x < width; x++)
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y))
+			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
 				iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, fg32);
 }
 
 static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip,
-				 const u8 *sbuf8, unsigned int spitch, u32 fg_color)
+				 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_panic_is_pixel_fg(sbuf8, spitch, x, y))
+			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
 				sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color);
 }
 
@@ -310,18 +322,22 @@ static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect
  * @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, u32 fg_color)
+			   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, fg_color);
+		return drm_panic_blit_pixel(sb, clip, sbuf8, spitch, scale, fg_color);
 
 	map = sb->map[0];
 	iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);
@@ -329,15 +345,15 @@ static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
 	switch (sb->format->cpp[0]) {
 	case 2:
 		drm_panic_blit16(&map, sb->pitch[0], sbuf8, spitch,
-				 drm_rect_height(clip), drm_rect_width(clip), fg_color);
+				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
 	break;
 	case 3:
 		drm_panic_blit24(&map, sb->pitch[0], sbuf8, spitch,
-				 drm_rect_height(clip), drm_rect_width(clip), fg_color);
+				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
 	break;
 	case 4:
 		drm_panic_blit32(&map, sb->pitch[0], sbuf8, spitch,
-				 drm_rect_height(clip), drm_rect_width(clip), fg_color);
+				 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]);
@@ -477,39 +493,51 @@ static void draw_txt_rectangle(struct drm_scanout_buffer *sb,
 		for (j = 0; j < line_len; j++) {
 			src = get_char_bitmap(font, msg[i].txt[j], font_pitch);
 			rec.x2 = rec.x1 + font->width;
-			drm_panic_blit(sb, &rec, src, font_pitch, color);
+			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 (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 void draw_panic_static_user(struct drm_scanout_buffer *sb)
 {
-	size_t msg_lines = ARRAY_SIZE(panic_msg);
-	size_t logo_ascii_lines = ARRAY_SIZE(logo_ascii);
 	u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
 	u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
 	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 logo_width, logo_height;
+	unsigned int msg_width, msg_height;
 
 	if (!font)
 		return;
 
 	r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
+	drm_panic_logo_rect(&r_logo, font);
 
-	if (logo_mono) {
-		logo_width = logo_mono->width;
-		logo_height = logo_mono->height;
-	} else {
-		logo_width = get_max_line_len(logo_ascii, logo_ascii_lines) * font->width;
-		logo_height = logo_ascii_lines * font->height;
-	}
-
-	r_logo = DRM_RECT_INIT(0, 0, logo_width, logo_height);
-	r_msg = DRM_RECT_INIT(0, 0,
-			      min(get_max_line_len(panic_msg, msg_lines) * font->width, sb->width),
-			      min(msg_lines * font->height, sb->height));
+	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);
@@ -517,16 +545,10 @@ static void draw_panic_static_user(struct drm_scanout_buffer *sb)
 	/* Fill with the background color, and draw text on top */
 	drm_panic_fill(sb, &r_screen, bg_color);
 
-	if ((r_msg.x1 >= logo_width || r_msg.y1 >= logo_height) &&
-	    logo_width <= sb->width && logo_height <= sb->height) {
-		if (logo_mono)
-			drm_panic_blit(sb, &r_logo, logo_mono->data, DIV_ROUND_UP(logo_width, 8),
-				       fg_color);
-		else
-			draw_txt_rectangle(sb, font, logo_ascii, logo_ascii_lines, false, &r_logo,
-					   fg_color);
-	}
-	draw_txt_rectangle(sb, font, panic_msg, msg_lines, true, &r_msg, fg_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);
 }
 
 /*
@@ -608,6 +630,233 @@ static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb)
 	}
 }
 
+#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 char *qrbuf1;
+static char *qrbuf2;
+static struct z_stream_s stream;
+
+static void __init drm_panic_qr_init(void)
+{
+	qrbuf1 = kmalloc(QR_BUFFER1_SIZE, GFP_KERNEL);
+	qrbuf2 = kmalloc(QR_BUFFER2_SIZE, GFP_KERNEL);
+	stream.workspace = kmalloc(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL),
+				   GFP_KERNEL);
+}
+
+static void drm_panic_qr_exit(void)
+{
+	kfree(qrbuf1);
+	qrbuf1 = NULL;
+	kfree(qrbuf2);
+	qrbuf2 = NULL;
+	kfree(stream.workspace);
+	stream.workspace = NULL;
+}
+
+extern size_t drm_panic_qr_max_data_size(u8 version, size_t url_len);
+
+extern u8 drm_panic_qr_generate(const char *url, u8 *data, size_t data_len, size_t data_size,
+				u8 *tmp, size_t tmp_size);
+
+static int drm_panic_get_qr_code_url(u8 **qr_image)
+{
+	struct kmsg_dump_iter iter;
+	char url[256];
+	size_t kmsg_len, max_kmsg_size;
+	char *kmsg;
+	int max_qr_data_size, url_len;
+
+	url_len = snprintf(url, sizeof(url), CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL "?a=%s&v=%s&zl=",
+			   utsname()->machine, utsname()->release);
+
+	max_qr_data_size = drm_panic_qr_max_data_size(panic_qr_version, url_len);
+	max_kmsg_size = min(MAX_ZLIB_RATIO * max_qr_data_size, QR_BUFFER1_SIZE);
+
+	/* 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 = QR_BUFFER2_SIZE;
+	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, QR_BUFFER2_SIZE,
+				     qrbuf1, QR_BUFFER1_SIZE);
+}
+
+static int drm_panic_get_qr_code_raw(u8 **qr_image)
+{
+	struct kmsg_dump_iter iter;
+	size_t kmsg_len;
+	size_t max_kmsg_size = min(drm_panic_qr_max_data_size(panic_qr_version, 0),
+				   QR_BUFFER1_SIZE);
+
+	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, QR_BUFFER1_SIZE,
+				     qrbuf2, QR_BUFFER2_SIZE);
+}
+
+static int drm_panic_get_qr_code(u8 **qr_image)
+{
+	if (strlen(CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL) > 0)
+		return drm_panic_get_qr_code_url(qr_image);
+	else
+		return drm_panic_get_qr_code_raw(qr_image);
+}
+
+/*
+ * Draw the panic message at the center of the screen, with a QR Code
+ */
+static int _draw_panic_static_qr_code(struct drm_scanout_buffer *sb)
+{
+	u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
+	u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
+	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 (!font || !qrbuf1 || !qrbuf2 || !stream.workspace)
+		return -ENOMEM;
+
+	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);
+	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)) / 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))
+		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;
+}
+
+static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb)
+{
+	if (_draw_panic_static_qr_code(sb))
+		draw_panic_static_user(sb);
+}
+#else
+static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb)
+{
+	draw_panic_static_user(sb);
+}
+
+static void drm_panic_qr_init(void) {};
+static void drm_panic_qr_exit(void) {};
+#endif
+
 /*
  * drm_panic_is_format_supported()
  * @format: a fourcc color code
@@ -626,12 +875,38 @@ static void draw_panic_dispatch(struct drm_scanout_buffer *sb)
 {
 	if (!strcmp(drm_panic_screen, "kmsg")) {
 		draw_panic_static_kmsg(sb);
+	} else if (!strcmp(drm_panic_screen, "qr_code")) {
+		draw_panic_static_qr_code(sb);
 	} else {
 		draw_panic_static_user(sb);
 	}
 }
 
-static void draw_panic_plane(struct drm_plane *plane)
+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;
+}
+
+static void draw_panic_plane(struct drm_plane *plane, const char *description)
 {
 	struct drm_scanout_buffer sb = { };
 	int ret;
@@ -640,6 +915,8 @@ static void draw_panic_plane(struct drm_plane *plane)
 	if (!drm_panic_trylock(plane->dev, flags))
 		return;
 
+	drm_panic_set_description(description);
+
 	ret = plane->helper_private->get_scanout_buffer(plane, &sb);
 
 	if (!ret && drm_panic_is_format_supported(sb.format)) {
@@ -647,6 +924,7 @@ static void draw_panic_plane(struct drm_plane *plane)
 		if (plane->helper_private->panic_flush)
 			plane->helper_private->panic_flush(plane);
 	}
+	drm_panic_clear_description();
 	drm_panic_unlock(plane->dev, flags);
 }
 
@@ -655,12 +933,12 @@ static struct drm_plane *to_drm_plane(struct kmsg_dumper *kd)
 	return container_of(kd, struct drm_plane, kmsg_panic);
 }
 
-static void drm_panic(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason)
+static void drm_panic(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detail)
 {
 	struct drm_plane *plane = to_drm_plane(dumper);
 
-	if (reason == KMSG_DUMP_PANIC)
-		draw_panic_plane(plane);
+	if (detail->reason == KMSG_DUMP_PANIC)
+		draw_panic_plane(plane, detail->description);
 }
 
 
@@ -680,7 +958,7 @@ static ssize_t debugfs_trigger_write(struct file *file, const char __user *user_
 	if (kstrtobool_from_user(user_buf, count, &run) == 0 && run) {
 		struct drm_plane *plane = file->private_data;
 
-		draw_panic_plane(plane);
+		draw_panic_plane(plane, "Test from debugfs");
 	}
 	return count;
 }
@@ -704,6 +982,26 @@ static void debugfs_register_plane(struct drm_plane *plane, int index) {}
 #endif /* CONFIG_DRM_PANIC_DEBUG */
 
 /**
+ * drm_panic_is_enabled
+ * @dev: the drm device that may supports drm_panic
+ *
+ * returns true if the drm device supports drm_panic
+ */
+bool drm_panic_is_enabled(struct drm_device *dev)
+{
+	struct drm_plane *plane;
+
+	if (!dev->mode_config.num_total_plane)
+		return false;
+
+	drm_for_each_plane(plane, dev)
+		if (plane->helper_private && plane->helper_private->get_scanout_buffer)
+			return true;
+	return false;
+}
+EXPORT_SYMBOL(drm_panic_is_enabled);
+
+/**
  * drm_panic_register() - Initialize DRM panic for a device
  * @dev: the drm device on which the panic screen will be displayed.
  */
@@ -730,7 +1028,6 @@ void drm_panic_register(struct drm_device *dev)
 	if (registered_plane)
 		drm_info(dev, "Registered %d planes with drm panic\n", registered_plane);
 }
-EXPORT_SYMBOL(drm_panic_register);
 
 /**
  * drm_panic_unregister()
@@ -749,4 +1046,19 @@ void drm_panic_unregister(struct drm_device *dev)
 		kmsg_dump_unregister(&plane->kmsg_panic);
 	}
 }
-EXPORT_SYMBOL(drm_panic_unregister);
+
+/**
+ * drm_panic_init() - initialize DRM panic.
+ */
+void __init drm_panic_init(void)
+{
+	drm_panic_qr_init();
+}
+
+/**
+ * drm_panic_exit() - Free the resources taken by drm_panic_exit()
+ */
+void drm_panic_exit(void)
+{
+	drm_panic_qr_exit();
+}