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1// SPDX-License-Identifier: GPL-2.0 or MIT2/*3 * Copyright (c) 2023 Red Hat.4 * Author: Jocelyn Falempe <jfalempe@redhat.com>5 * inspired by the drm_log driver from David Herrmann <dh.herrmann@gmail.com>6 * Tux Ascii art taken from cowsay written by Tony Monroe7 */8 9#include <linux/font.h>10#include <linux/init.h>11#include <linux/iosys-map.h>12#include <linux/kdebug.h>13#include <linux/kmsg_dump.h>14#include <linux/linux_logo.h>15#include <linux/list.h>16#include <linux/math.h>17#include <linux/module.h>18#include <linux/overflow.h>19#include <linux/printk.h>20#include <linux/types.h>21#include <linux/utsname.h>22#include <linux/zlib.h>23 24#include <drm/drm_drv.h>25#include <drm/drm_fourcc.h>26#include <drm/drm_framebuffer.h>27#include <drm/drm_modeset_helper_vtables.h>28#include <drm/drm_panic.h>29#include <drm/drm_plane.h>30#include <drm/drm_print.h>31#include <drm/drm_rect.h>32 33#include "drm_crtc_internal.h"34 35MODULE_AUTHOR("Jocelyn Falempe");36MODULE_DESCRIPTION("DRM panic handler");37MODULE_LICENSE("GPL");38 39static char drm_panic_screen[16] = CONFIG_DRM_PANIC_SCREEN;40module_param_string(panic_screen, drm_panic_screen, sizeof(drm_panic_screen), 0644);41MODULE_PARM_DESC(panic_screen,42 "Choose what will be displayed by drm_panic, 'user' or 'kmsg' [default="43 CONFIG_DRM_PANIC_SCREEN "]");44 45/**46 * DOC: overview47 *48 * To enable DRM panic for a driver, the primary plane must implement a49 * &drm_plane_helper_funcs.get_scanout_buffer helper function. It is then50 * automatically registered to the drm panic handler.51 * When a panic occurs, the &drm_plane_helper_funcs.get_scanout_buffer will be52 * called, and the driver can provide a framebuffer so the panic handler can53 * draw the panic screen on it. Currently only linear buffer and a few color54 * formats are supported.55 * Optionally the driver can also provide a &drm_plane_helper_funcs.panic_flush56 * callback, that will be called after that, to send additional commands to the57 * hardware to make the scanout buffer visible.58 */59 60/*61 * This module displays a user friendly message on screen when a kernel panic62 * occurs. This is conflicting with fbcon, so you can only enable it when fbcon63 * is disabled.64 * It's intended for end-user, so have minimal technical/debug information.65 *66 * Implementation details:67 *68 * It is a panic handler, so it can't take lock, allocate memory, run tasks/irq,69 * or attempt to sleep. It's a best effort, and it may not be able to display70 * the message in all situations (like if the panic occurs in the middle of a71 * modesetting).72 * It will display only one static frame, so performance optimizations are low73 * priority as the machine is already in an unusable state.74 */75 76struct drm_panic_line {77 u32 len;78 const char *txt;79};80 81#define PANIC_LINE(s) {.len = sizeof(s) - 1, .txt = s}82 83static struct drm_panic_line panic_msg[] = {84 PANIC_LINE("KERNEL PANIC!"),85 PANIC_LINE(""),86 PANIC_LINE("Please reboot your computer."),87 PANIC_LINE(""),88 PANIC_LINE(""), /* will be replaced by the panic description */89};90 91static const size_t panic_msg_lines = ARRAY_SIZE(panic_msg);92 93static const struct drm_panic_line logo_ascii[] = {94 PANIC_LINE(" .--. _"),95 PANIC_LINE(" |o_o | | |"),96 PANIC_LINE(" |:_/ | | |"),97 PANIC_LINE(" // \\ \\ |_|"),98 PANIC_LINE(" (| | ) _"),99 PANIC_LINE(" /'\\_ _/`\\ (_)"),100 PANIC_LINE(" \\___)=(___/"),101};102 103static const size_t logo_ascii_lines = ARRAY_SIZE(logo_ascii);104 105#if defined(CONFIG_LOGO) && !defined(MODULE)106static const struct linux_logo *logo_mono;107 108static int drm_panic_setup_logo(void)109{110 const struct linux_logo *logo = fb_find_logo(1);111 const unsigned char *logo_data;112 struct linux_logo *logo_dup;113 114 if (!logo || logo->type != LINUX_LOGO_MONO)115 return 0;116 117 /* The logo is __init, so we must make a copy for later use */118 logo_data = kmemdup(logo->data,119 size_mul(DIV_ROUND_UP(logo->width, BITS_PER_BYTE), logo->height),120 GFP_KERNEL);121 if (!logo_data)122 return -ENOMEM;123 124 logo_dup = kmemdup(logo, sizeof(*logo), GFP_KERNEL);125 if (!logo_dup) {126 kfree(logo_data);127 return -ENOMEM;128 }129 130 logo_dup->data = logo_data;131 logo_mono = logo_dup;132 133 return 0;134}135 136device_initcall(drm_panic_setup_logo);137#else138#define logo_mono ((const struct linux_logo *)NULL)139#endif140 141/*142 * Color conversion143 */144 145static u16 convert_xrgb8888_to_rgb565(u32 pix)146{147 return ((pix & 0x00F80000) >> 8) |148 ((pix & 0x0000FC00) >> 5) |149 ((pix & 0x000000F8) >> 3);150}151 152static u16 convert_xrgb8888_to_rgba5551(u32 pix)153{154 return ((pix & 0x00f80000) >> 8) |155 ((pix & 0x0000f800) >> 5) |156 ((pix & 0x000000f8) >> 2) |157 BIT(0); /* set alpha bit */158}159 160static u16 convert_xrgb8888_to_xrgb1555(u32 pix)161{162 return ((pix & 0x00f80000) >> 9) |163 ((pix & 0x0000f800) >> 6) |164 ((pix & 0x000000f8) >> 3);165}166 167static u16 convert_xrgb8888_to_argb1555(u32 pix)168{169 return BIT(15) | /* set alpha bit */170 ((pix & 0x00f80000) >> 9) |171 ((pix & 0x0000f800) >> 6) |172 ((pix & 0x000000f8) >> 3);173}174 175static u32 convert_xrgb8888_to_argb8888(u32 pix)176{177 return pix | GENMASK(31, 24); /* fill alpha bits */178}179 180static u32 convert_xrgb8888_to_xbgr8888(u32 pix)181{182 return ((pix & 0x00ff0000) >> 16) << 0 |183 ((pix & 0x0000ff00) >> 8) << 8 |184 ((pix & 0x000000ff) >> 0) << 16 |185 ((pix & 0xff000000) >> 24) << 24;186}187 188static u32 convert_xrgb8888_to_abgr8888(u32 pix)189{190 return ((pix & 0x00ff0000) >> 16) << 0 |191 ((pix & 0x0000ff00) >> 8) << 8 |192 ((pix & 0x000000ff) >> 0) << 16 |193 GENMASK(31, 24); /* fill alpha bits */194}195 196static u32 convert_xrgb8888_to_xrgb2101010(u32 pix)197{198 pix = ((pix & 0x000000FF) << 2) |199 ((pix & 0x0000FF00) << 4) |200 ((pix & 0x00FF0000) << 6);201 return pix | ((pix >> 8) & 0x00300C03);202}203 204static u32 convert_xrgb8888_to_argb2101010(u32 pix)205{206 pix = ((pix & 0x000000FF) << 2) |207 ((pix & 0x0000FF00) << 4) |208 ((pix & 0x00FF0000) << 6);209 return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);210}211 212/*213 * convert_from_xrgb8888 - convert one pixel from xrgb8888 to the desired format214 * @color: input color, in xrgb8888 format215 * @format: output format216 *217 * Returns:218 * Color in the format specified, casted to u32.219 * Or 0 if the format is not supported.220 */221static u32 convert_from_xrgb8888(u32 color, u32 format)222{223 switch (format) {224 case DRM_FORMAT_RGB565:225 return convert_xrgb8888_to_rgb565(color);226 case DRM_FORMAT_RGBA5551:227 return convert_xrgb8888_to_rgba5551(color);228 case DRM_FORMAT_XRGB1555:229 return convert_xrgb8888_to_xrgb1555(color);230 case DRM_FORMAT_ARGB1555:231 return convert_xrgb8888_to_argb1555(color);232 case DRM_FORMAT_RGB888:233 case DRM_FORMAT_XRGB8888:234 return color;235 case DRM_FORMAT_ARGB8888:236 return convert_xrgb8888_to_argb8888(color);237 case DRM_FORMAT_XBGR8888:238 return convert_xrgb8888_to_xbgr8888(color);239 case DRM_FORMAT_ABGR8888:240 return convert_xrgb8888_to_abgr8888(color);241 case DRM_FORMAT_XRGB2101010:242 return convert_xrgb8888_to_xrgb2101010(color);243 case DRM_FORMAT_ARGB2101010:244 return convert_xrgb8888_to_argb2101010(color);245 default:246 WARN_ONCE(1, "Can't convert to %p4cc\n", &format);247 return 0;248 }249}250 251/*252 * Blit & Fill253 */254/* check if the pixel at coord x,y is 1 (foreground) or 0 (background) */255static bool drm_panic_is_pixel_fg(const u8 *sbuf8, unsigned int spitch, int x, int y)256{257 return (sbuf8[(y * spitch) + x / 8] & (0x80 >> (x % 8))) != 0;258}259 260static void drm_panic_blit16(struct iosys_map *dmap, unsigned int dpitch,261 const u8 *sbuf8, unsigned int spitch,262 unsigned int height, unsigned int width,263 unsigned int scale, u16 fg16)264{265 unsigned int y, x;266 267 for (y = 0; y < height; y++)268 for (x = 0; x < width; x++)269 if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))270 iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, fg16);271}272 273static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,274 const u8 *sbuf8, unsigned int spitch,275 unsigned int height, unsigned int width,276 unsigned int scale, u32 fg32)277{278 unsigned int y, x;279 280 for (y = 0; y < height; y++) {281 for (x = 0; x < width; x++) {282 u32 off = y * dpitch + x * 3;283 284 if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) {285 /* write blue-green-red to output in little endianness */286 iosys_map_wr(dmap, off, u8, (fg32 & 0x000000FF) >> 0);287 iosys_map_wr(dmap, off + 1, u8, (fg32 & 0x0000FF00) >> 8);288 iosys_map_wr(dmap, off + 2, u8, (fg32 & 0x00FF0000) >> 16);289 }290 }291 }292}293 294static void drm_panic_blit32(struct iosys_map *dmap, unsigned int dpitch,295 const u8 *sbuf8, unsigned int spitch,296 unsigned int height, unsigned int width,297 unsigned int scale, u32 fg32)298{299 unsigned int y, x;300 301 for (y = 0; y < height; y++)302 for (x = 0; x < width; x++)303 if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))304 iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, fg32);305}306 307static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip,308 const u8 *sbuf8, unsigned int spitch, unsigned int scale,309 u32 fg_color)310{311 unsigned int y, x;312 313 for (y = 0; y < drm_rect_height(clip); y++)314 for (x = 0; x < drm_rect_width(clip); x++)315 if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))316 sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color);317}318 319/*320 * drm_panic_blit - convert a monochrome image to a linear framebuffer321 * @sb: destination scanout buffer322 * @clip: destination rectangle323 * @sbuf8: source buffer, in monochrome format, 8 pixels per byte.324 * @spitch: source pitch in bytes325 * @scale: integer scale, source buffer is scale time smaller than destination326 * rectangle327 * @fg_color: foreground color, in destination format328 *329 * This can be used to draw a font character, which is a monochrome image, to a330 * framebuffer in other supported format.331 */332static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,333 const u8 *sbuf8, unsigned int spitch,334 unsigned int scale, u32 fg_color)335 336{337 struct iosys_map map;338 339 if (sb->set_pixel)340 return drm_panic_blit_pixel(sb, clip, sbuf8, spitch, scale, fg_color);341 342 map = sb->map[0];343 iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);344 345 switch (sb->format->cpp[0]) {346 case 2:347 drm_panic_blit16(&map, sb->pitch[0], sbuf8, spitch,348 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);349 break;350 case 3:351 drm_panic_blit24(&map, sb->pitch[0], sbuf8, spitch,352 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);353 break;354 case 4:355 drm_panic_blit32(&map, sb->pitch[0], sbuf8, spitch,356 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);357 break;358 default:359 WARN_ONCE(1, "Can't blit with pixel width %d\n", sb->format->cpp[0]);360 }361}362 363static void drm_panic_fill16(struct iosys_map *dmap, unsigned int dpitch,364 unsigned int height, unsigned int width,365 u16 color)366{367 unsigned int y, x;368 369 for (y = 0; y < height; y++)370 for (x = 0; x < width; x++)371 iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, color);372}373 374static void drm_panic_fill24(struct iosys_map *dmap, unsigned int dpitch,375 unsigned int height, unsigned int width,376 u32 color)377{378 unsigned int y, x;379 380 for (y = 0; y < height; y++) {381 for (x = 0; x < width; x++) {382 unsigned int off = y * dpitch + x * 3;383 384 /* write blue-green-red to output in little endianness */385 iosys_map_wr(dmap, off, u8, (color & 0x000000FF) >> 0);386 iosys_map_wr(dmap, off + 1, u8, (color & 0x0000FF00) >> 8);387 iosys_map_wr(dmap, off + 2, u8, (color & 0x00FF0000) >> 16);388 }389 }390}391 392static void drm_panic_fill32(struct iosys_map *dmap, unsigned int dpitch,393 unsigned int height, unsigned int width,394 u32 color)395{396 unsigned int y, x;397 398 for (y = 0; y < height; y++)399 for (x = 0; x < width; x++)400 iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, color);401}402 403static void drm_panic_fill_pixel(struct drm_scanout_buffer *sb,404 struct drm_rect *clip,405 u32 color)406{407 unsigned int y, x;408 409 for (y = 0; y < drm_rect_height(clip); y++)410 for (x = 0; x < drm_rect_width(clip); x++)411 sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, color);412}413 414/*415 * drm_panic_fill - Fill a rectangle with a color416 * @sb: destination scanout buffer417 * @clip: destination rectangle418 * @color: foreground color, in destination format419 *420 * Fill a rectangle with a color, in a linear framebuffer.421 */422static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip,423 u32 color)424{425 struct iosys_map map;426 427 if (sb->set_pixel)428 return drm_panic_fill_pixel(sb, clip, color);429 430 map = sb->map[0];431 iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);432 433 switch (sb->format->cpp[0]) {434 case 2:435 drm_panic_fill16(&map, sb->pitch[0], drm_rect_height(clip),436 drm_rect_width(clip), color);437 break;438 case 3:439 drm_panic_fill24(&map, sb->pitch[0], drm_rect_height(clip),440 drm_rect_width(clip), color);441 break;442 case 4:443 drm_panic_fill32(&map, sb->pitch[0], drm_rect_height(clip),444 drm_rect_width(clip), color);445 break;446 default:447 WARN_ONCE(1, "Can't fill with pixel width %d\n", sb->format->cpp[0]);448 }449}450 451static const u8 *get_char_bitmap(const struct font_desc *font, char c, size_t font_pitch)452{453 return font->data + (c * font->height) * font_pitch;454}455 456static unsigned int get_max_line_len(const struct drm_panic_line *lines, int len)457{458 int i;459 unsigned int max = 0;460 461 for (i = 0; i < len; i++)462 max = max(lines[i].len, max);463 return max;464}465 466/*467 * Draw a text in a rectangle on a framebuffer. The text is truncated if it overflows the rectangle468 */469static void draw_txt_rectangle(struct drm_scanout_buffer *sb,470 const struct font_desc *font,471 const struct drm_panic_line *msg,472 unsigned int msg_lines,473 bool centered,474 struct drm_rect *clip,475 u32 color)476{477 int i, j;478 const u8 *src;479 size_t font_pitch = DIV_ROUND_UP(font->width, 8);480 struct drm_rect rec;481 482 msg_lines = min(msg_lines, drm_rect_height(clip) / font->height);483 for (i = 0; i < msg_lines; i++) {484 size_t line_len = min(msg[i].len, drm_rect_width(clip) / font->width);485 486 rec.y1 = clip->y1 + i * font->height;487 rec.y2 = rec.y1 + font->height;488 rec.x1 = clip->x1;489 490 if (centered)491 rec.x1 += (drm_rect_width(clip) - (line_len * font->width)) / 2;492 493 for (j = 0; j < line_len; j++) {494 src = get_char_bitmap(font, msg[i].txt[j], font_pitch);495 rec.x2 = rec.x1 + font->width;496 drm_panic_blit(sb, &rec, src, font_pitch, 1, color);497 rec.x1 += font->width;498 }499 }500}501 502static void drm_panic_logo_rect(struct drm_rect *rect, const struct font_desc *font)503{504 if (logo_mono) {505 drm_rect_init(rect, 0, 0, logo_mono->width, logo_mono->height);506 } else {507 int logo_width = get_max_line_len(logo_ascii, logo_ascii_lines) * font->width;508 509 drm_rect_init(rect, 0, 0, logo_width, logo_ascii_lines * font->height);510 }511}512 513static void drm_panic_logo_draw(struct drm_scanout_buffer *sb, struct drm_rect *rect,514 const struct font_desc *font, u32 fg_color)515{516 if (logo_mono)517 drm_panic_blit(sb, rect, logo_mono->data,518 DIV_ROUND_UP(drm_rect_width(rect), 8), 1, fg_color);519 else520 draw_txt_rectangle(sb, font, logo_ascii, logo_ascii_lines, false, rect,521 fg_color);522}523 524static void draw_panic_static_user(struct drm_scanout_buffer *sb)525{526 u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);527 u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);528 const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);529 struct drm_rect r_screen, r_logo, r_msg;530 unsigned int msg_width, msg_height;531 532 if (!font)533 return;534 535 r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);536 drm_panic_logo_rect(&r_logo, font);537 538 msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width);539 msg_height = min(panic_msg_lines * font->height, sb->height);540 r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height);541 542 /* Center the panic message */543 drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, (sb->height - r_msg.y2) / 2);544 545 /* Fill with the background color, and draw text on top */546 drm_panic_fill(sb, &r_screen, bg_color);547 548 if (!drm_rect_overlap(&r_logo, &r_msg))549 drm_panic_logo_draw(sb, &r_logo, font, fg_color);550 551 draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color);552}553 554/*555 * Draw one line of kmsg, and handle wrapping if it won't fit in the screen width.556 * Return the y-offset of the next line.557 */558static int draw_line_with_wrap(struct drm_scanout_buffer *sb, const struct font_desc *font,559 struct drm_panic_line *line, int yoffset, u32 fg_color)560{561 int chars_per_row = sb->width / font->width;562 struct drm_rect r_txt = DRM_RECT_INIT(0, yoffset, sb->width, sb->height);563 struct drm_panic_line line_wrap;564 565 if (line->len > chars_per_row) {566 line_wrap.len = line->len % chars_per_row;567 line_wrap.txt = line->txt + line->len - line_wrap.len;568 draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color);569 r_txt.y1 -= font->height;570 if (r_txt.y1 < 0)571 return r_txt.y1;572 while (line_wrap.txt > line->txt) {573 line_wrap.txt -= chars_per_row;574 line_wrap.len = chars_per_row;575 draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color);576 r_txt.y1 -= font->height;577 if (r_txt.y1 < 0)578 return r_txt.y1;579 }580 } else {581 draw_txt_rectangle(sb, font, line, 1, false, &r_txt, fg_color);582 r_txt.y1 -= font->height;583 }584 return r_txt.y1;585}586 587/*588 * Draw the kmsg buffer to the screen, starting from the youngest message at the bottom,589 * and going up until reaching the top of the screen.590 */591static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb)592{593 u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);594 u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);595 const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);596 struct drm_rect r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);597 struct kmsg_dump_iter iter;598 char kmsg_buf[512];599 size_t kmsg_len;600 struct drm_panic_line line;601 int yoffset;602 603 if (!font)604 return;605 606 yoffset = sb->height - font->height - (sb->height % font->height) / 2;607 608 /* Fill with the background color, and draw text on top */609 drm_panic_fill(sb, &r_screen, bg_color);610 611 kmsg_dump_rewind(&iter);612 while (kmsg_dump_get_buffer(&iter, false, kmsg_buf, sizeof(kmsg_buf), &kmsg_len)) {613 char *start;614 char *end;615 616 /* ignore terminating NUL and newline */617 start = kmsg_buf + kmsg_len - 2;618 end = kmsg_buf + kmsg_len - 1;619 while (start > kmsg_buf && yoffset >= 0) {620 while (start > kmsg_buf && *start != '\n')621 start--;622 /* don't count the newline character */623 line.txt = start + (start == kmsg_buf ? 0 : 1);624 line.len = end - line.txt;625 626 yoffset = draw_line_with_wrap(sb, font, &line, yoffset, fg_color);627 end = start;628 start--;629 }630 }631}632 633#if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE)634/*635 * It is unwise to allocate memory in the panic callback, so the buffers are636 * pre-allocated. Only 2 buffers and the zlib workspace are needed.637 * Two buffers are enough, using the following buffer usage:638 * 1) kmsg messages are dumped in buffer1639 * 2) kmsg is zlib-compressed into buffer2640 * 3) compressed kmsg is encoded as QR-code Numeric stream in buffer1641 * 4) QR-code image is generated in buffer2642 * The Max QR code size is V40, 177x177, 4071 bytes for image, 2956 bytes for643 * data segments.644 *645 * Typically, ~7500 bytes of kmsg, are compressed into 2800 bytes, which fits in646 * a V40 QR-code (177x177).647 *648 * If CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL is not set, the kmsg data will be put649 * directly in the QR code.650 * 1) kmsg messages are dumped in buffer1651 * 2) kmsg message is encoded as byte stream in buffer2652 * 3) QR-code image is generated in buffer1653 */654 655static uint panic_qr_version = CONFIG_DRM_PANIC_SCREEN_QR_VERSION;656module_param(panic_qr_version, uint, 0644);657MODULE_PARM_DESC(panic_qr_version, "maximum version (size) of the QR code");658 659#define MAX_QR_DATA 2956660#define MAX_ZLIB_RATIO 3661#define QR_BUFFER1_SIZE (MAX_ZLIB_RATIO * MAX_QR_DATA) /* Must also be > 4071 */662#define QR_BUFFER2_SIZE 4096663#define QR_MARGIN 4 /* 4 modules of foreground color around the qr code */664 665/* Compression parameters */666#define COMPR_LEVEL 6667#define WINDOW_BITS 12668#define MEM_LEVEL 4669 670static char *qrbuf1;671static char *qrbuf2;672static struct z_stream_s stream;673 674static void __init drm_panic_qr_init(void)675{676 qrbuf1 = kmalloc(QR_BUFFER1_SIZE, GFP_KERNEL);677 qrbuf2 = kmalloc(QR_BUFFER2_SIZE, GFP_KERNEL);678 stream.workspace = kmalloc(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL),679 GFP_KERNEL);680}681 682static void drm_panic_qr_exit(void)683{684 kfree(qrbuf1);685 qrbuf1 = NULL;686 kfree(qrbuf2);687 qrbuf2 = NULL;688 kfree(stream.workspace);689 stream.workspace = NULL;690}691 692extern size_t drm_panic_qr_max_data_size(u8 version, size_t url_len);693 694extern u8 drm_panic_qr_generate(const char *url, u8 *data, size_t data_len, size_t data_size,695 u8 *tmp, size_t tmp_size);696 697static int drm_panic_get_qr_code_url(u8 **qr_image)698{699 struct kmsg_dump_iter iter;700 char url[256];701 size_t kmsg_len, max_kmsg_size;702 char *kmsg;703 int max_qr_data_size, url_len;704 705 url_len = snprintf(url, sizeof(url), CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL "?a=%s&v=%s&zl=",706 utsname()->machine, utsname()->release);707 708 max_qr_data_size = drm_panic_qr_max_data_size(panic_qr_version, url_len);709 max_kmsg_size = min(MAX_ZLIB_RATIO * max_qr_data_size, QR_BUFFER1_SIZE);710 711 /* get kmsg to buffer 1 */712 kmsg_dump_rewind(&iter);713 kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len);714 715 if (!kmsg_len)716 return -ENODATA;717 kmsg = qrbuf1;718 719try_again:720 if (zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,721 MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK)722 return -EINVAL;723 724 stream.next_in = kmsg;725 stream.avail_in = kmsg_len;726 stream.total_in = 0;727 stream.next_out = qrbuf2;728 stream.avail_out = QR_BUFFER2_SIZE;729 stream.total_out = 0;730 731 if (zlib_deflate(&stream, Z_FINISH) != Z_STREAM_END)732 return -EINVAL;733 734 if (zlib_deflateEnd(&stream) != Z_OK)735 return -EINVAL;736 737 if (stream.total_out > max_qr_data_size) {738 /* too much data for the QR code, so skip the first line and try again */739 kmsg = strchr(kmsg, '\n');740 if (!kmsg)741 return -EINVAL;742 /* skip the first \n */743 kmsg += 1;744 kmsg_len = strlen(kmsg);745 goto try_again;746 }747 *qr_image = qrbuf2;748 749 /* generate qr code image in buffer2 */750 return drm_panic_qr_generate(url, qrbuf2, stream.total_out, QR_BUFFER2_SIZE,751 qrbuf1, QR_BUFFER1_SIZE);752}753 754static int drm_panic_get_qr_code_raw(u8 **qr_image)755{756 struct kmsg_dump_iter iter;757 size_t kmsg_len;758 size_t max_kmsg_size = min(drm_panic_qr_max_data_size(panic_qr_version, 0),759 QR_BUFFER1_SIZE);760 761 kmsg_dump_rewind(&iter);762 kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len);763 if (!kmsg_len)764 return -ENODATA;765 766 *qr_image = qrbuf1;767 return drm_panic_qr_generate(NULL, qrbuf1, kmsg_len, QR_BUFFER1_SIZE,768 qrbuf2, QR_BUFFER2_SIZE);769}770 771static int drm_panic_get_qr_code(u8 **qr_image)772{773 if (strlen(CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL) > 0)774 return drm_panic_get_qr_code_url(qr_image);775 else776 return drm_panic_get_qr_code_raw(qr_image);777}778 779/*780 * Draw the panic message at the center of the screen, with a QR Code781 */782static int _draw_panic_static_qr_code(struct drm_scanout_buffer *sb)783{784 u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);785 u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);786 const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);787 struct drm_rect r_screen, r_logo, r_msg, r_qr, r_qr_canvas;788 unsigned int max_qr_size, scale;789 unsigned int msg_width, msg_height;790 int qr_width, qr_canvas_width, qr_pitch, v_margin;791 u8 *qr_image;792 793 if (!font || !qrbuf1 || !qrbuf2 || !stream.workspace)794 return -ENOMEM;795 796 r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);797 798 drm_panic_logo_rect(&r_logo, font);799 800 msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width);801 msg_height = min(panic_msg_lines * font->height, sb->height);802 r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height);803 804 max_qr_size = min(3 * sb->width / 4, 3 * sb->height / 4);805 806 qr_width = drm_panic_get_qr_code(&qr_image);807 if (qr_width <= 0)808 return -ENOSPC;809 810 qr_canvas_width = qr_width + QR_MARGIN * 2;811 scale = max_qr_size / qr_canvas_width;812 /* QR code is not readable if not scaled at least by 2 */813 if (scale < 2)814 return -ENOSPC;815 816 pr_debug("QR width %d and scale %d\n", qr_width, scale);817 r_qr_canvas = DRM_RECT_INIT(0, 0, qr_canvas_width * scale, qr_canvas_width * scale);818 819 v_margin = (sb->height - drm_rect_height(&r_qr_canvas) - drm_rect_height(&r_msg)) / 5;820 821 drm_rect_translate(&r_qr_canvas, (sb->width - r_qr_canvas.x2) / 2, 2 * v_margin);822 r_qr = DRM_RECT_INIT(r_qr_canvas.x1 + QR_MARGIN * scale, r_qr_canvas.y1 + QR_MARGIN * scale,823 qr_width * scale, qr_width * scale);824 825 /* Center the panic message */826 drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2,827 3 * v_margin + drm_rect_height(&r_qr_canvas));828 829 /* Fill with the background color, and draw text on top */830 drm_panic_fill(sb, &r_screen, bg_color);831 832 if (!drm_rect_overlap(&r_logo, &r_msg) && !drm_rect_overlap(&r_logo, &r_qr))833 drm_panic_logo_draw(sb, &r_logo, font, fg_color);834 835 draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color);836 837 /* Draw the qr code */838 qr_pitch = DIV_ROUND_UP(qr_width, 8);839 drm_panic_fill(sb, &r_qr_canvas, fg_color);840 drm_panic_fill(sb, &r_qr, bg_color);841 drm_panic_blit(sb, &r_qr, qr_image, qr_pitch, scale, fg_color);842 return 0;843}844 845static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb)846{847 if (_draw_panic_static_qr_code(sb))848 draw_panic_static_user(sb);849}850#else851static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb)852{853 draw_panic_static_user(sb);854}855 856static void drm_panic_qr_init(void) {};857static void drm_panic_qr_exit(void) {};858#endif859 860/*861 * drm_panic_is_format_supported()862 * @format: a fourcc color code863 * Returns: true if supported, false otherwise.864 *865 * Check if drm_panic will be able to use this color format.866 */867static bool drm_panic_is_format_supported(const struct drm_format_info *format)868{869 if (format->num_planes != 1)870 return false;871 return convert_from_xrgb8888(0xffffff, format->format) != 0;872}873 874static void draw_panic_dispatch(struct drm_scanout_buffer *sb)875{876 if (!strcmp(drm_panic_screen, "kmsg")) {877 draw_panic_static_kmsg(sb);878 } else if (!strcmp(drm_panic_screen, "qr_code")) {879 draw_panic_static_qr_code(sb);880 } else {881 draw_panic_static_user(sb);882 }883}884 885static void drm_panic_set_description(const char *description)886{887 u32 len;888 889 if (description) {890 struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1];891 892 desc_line->txt = description;893 len = strlen(description);894 /* ignore the last newline character */895 if (len && description[len - 1] == '\n')896 len -= 1;897 desc_line->len = len;898 }899}900 901static void drm_panic_clear_description(void)902{903 struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1];904 905 desc_line->len = 0;906 desc_line->txt = NULL;907}908 909static void draw_panic_plane(struct drm_plane *plane, const char *description)910{911 struct drm_scanout_buffer sb = { };912 int ret;913 unsigned long flags;914 915 if (!drm_panic_trylock(plane->dev, flags))916 return;917 918 drm_panic_set_description(description);919 920 ret = plane->helper_private->get_scanout_buffer(plane, &sb);921 922 if (!ret && drm_panic_is_format_supported(sb.format)) {923 draw_panic_dispatch(&sb);924 if (plane->helper_private->panic_flush)925 plane->helper_private->panic_flush(plane);926 }927 drm_panic_clear_description();928 drm_panic_unlock(plane->dev, flags);929}930 931static struct drm_plane *to_drm_plane(struct kmsg_dumper *kd)932{933 return container_of(kd, struct drm_plane, kmsg_panic);934}935 936static void drm_panic(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detail)937{938 struct drm_plane *plane = to_drm_plane(dumper);939 940 if (detail->reason == KMSG_DUMP_PANIC)941 draw_panic_plane(plane, detail->description);942}943 944 945/*946 * DEBUG FS, This is currently unsafe.947 * Create one file per plane, so it's possible to debug one plane at a time.948 * TODO: It would be better to emulate an NMI context.949 */950#ifdef CONFIG_DRM_PANIC_DEBUG951#include <linux/debugfs.h>952 953static ssize_t debugfs_trigger_write(struct file *file, const char __user *user_buf,954 size_t count, loff_t *ppos)955{956 bool run;957 958 if (kstrtobool_from_user(user_buf, count, &run) == 0 && run) {959 struct drm_plane *plane = file->private_data;960 961 draw_panic_plane(plane, "Test from debugfs");962 }963 return count;964}965 966static const struct file_operations dbg_drm_panic_ops = {967 .owner = THIS_MODULE,968 .write = debugfs_trigger_write,969 .open = simple_open,970};971 972static void debugfs_register_plane(struct drm_plane *plane, int index)973{974 char fname[32];975 976 snprintf(fname, 32, "drm_panic_plane_%d", index);977 debugfs_create_file(fname, 0200, plane->dev->debugfs_root,978 plane, &dbg_drm_panic_ops);979}980#else981static void debugfs_register_plane(struct drm_plane *plane, int index) {}982#endif /* CONFIG_DRM_PANIC_DEBUG */983 984/**985 * drm_panic_is_enabled986 * @dev: the drm device that may supports drm_panic987 *988 * returns true if the drm device supports drm_panic989 */990bool drm_panic_is_enabled(struct drm_device *dev)991{992 struct drm_plane *plane;993 994 if (!dev->mode_config.num_total_plane)995 return false;996 997 drm_for_each_plane(plane, dev)998 if (plane->helper_private && plane->helper_private->get_scanout_buffer)999 return true;1000 return false;1001}1002EXPORT_SYMBOL(drm_panic_is_enabled);1003 1004/**1005 * drm_panic_register() - Initialize DRM panic for a device1006 * @dev: the drm device on which the panic screen will be displayed.1007 */1008void drm_panic_register(struct drm_device *dev)1009{1010 struct drm_plane *plane;1011 int registered_plane = 0;1012 1013 if (!dev->mode_config.num_total_plane)1014 return;1015 1016 drm_for_each_plane(plane, dev) {1017 if (!plane->helper_private || !plane->helper_private->get_scanout_buffer)1018 continue;1019 plane->kmsg_panic.dump = drm_panic;1020 plane->kmsg_panic.max_reason = KMSG_DUMP_PANIC;1021 if (kmsg_dump_register(&plane->kmsg_panic))1022 drm_warn(dev, "Failed to register panic handler\n");1023 else {1024 debugfs_register_plane(plane, registered_plane);1025 registered_plane++;1026 }1027 }1028 if (registered_plane)1029 drm_info(dev, "Registered %d planes with drm panic\n", registered_plane);1030}1031 1032/**1033 * drm_panic_unregister()1034 * @dev: the drm device previously registered.1035 */1036void drm_panic_unregister(struct drm_device *dev)1037{1038 struct drm_plane *plane;1039 1040 if (!dev->mode_config.num_total_plane)1041 return;1042 1043 drm_for_each_plane(plane, dev) {1044 if (!plane->helper_private || !plane->helper_private->get_scanout_buffer)1045 continue;1046 kmsg_dump_unregister(&plane->kmsg_panic);1047 }1048}1049 1050/**1051 * drm_panic_init() - initialize DRM panic.1052 */1053void __init drm_panic_init(void)1054{1055 drm_panic_qr_init();1056}1057 1058/**1059 * drm_panic_exit() - Free the resources taken by drm_panic_exit()1060 */1061void drm_panic_exit(void)1062{1063 drm_panic_qr_exit();1064}1065