1 // SPDX-License-Identifier: GPL-2.0 or MIT 2 /* 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 Monroe 7 */ 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 35 MODULE_AUTHOR("Jocelyn Falempe"); 36 MODULE_DESCRIPTION("DRM panic handler"); 37 MODULE_LICENSE("GPL"); 38 39 static char drm_panic_screen[16] = CONFIG_DRM_PANIC_SCREEN; 40 module_param_string(panic_screen, drm_panic_screen, sizeof(drm_panic_screen), 0644); 41 MODULE_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: overview 47 * 48 * To enable DRM panic for a driver, the primary plane must implement a 49 * &drm_plane_helper_funcs.get_scanout_buffer helper function. It is then 50 * automatically registered to the drm panic handler. 51 * When a panic occurs, the &drm_plane_helper_funcs.get_scanout_buffer will be 52 * called, and the driver can provide a framebuffer so the panic handler can 53 * draw the panic screen on it. Currently only linear buffer and a few color 54 * formats are supported. 55 * Optionally the driver can also provide a &drm_plane_helper_funcs.panic_flush 56 * callback, that will be called after that, to send additional commands to the 57 * hardware to make the scanout buffer visible. 58 */ 59 60 /* 61 * This module displays a user friendly message on screen when a kernel panic 62 * occurs. This is conflicting with fbcon, so you can only enable it when fbcon 63 * 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 display 70 * the message in all situations (like if the panic occurs in the middle of a 71 * modesetting). 72 * It will display only one static frame, so performance optimizations are low 73 * priority as the machine is already in an unusable state. 74 */ 75 76 struct drm_panic_line { 77 u32 len; 78 const char *txt; 79 }; 80 81 #define PANIC_LINE(s) {.len = sizeof(s) - 1, .txt = s} 82 83 static 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 91 static const size_t panic_msg_lines = ARRAY_SIZE(panic_msg); 92 93 static 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 }; 102 103 static const size_t logo_ascii_lines = ARRAY_SIZE(logo_ascii); 104 105 #if defined(CONFIG_LOGO) && !defined(MODULE) 106 static const struct linux_logo *logo_mono; 107 108 static 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 } 135 136 device_initcall(drm_panic_setup_logo); 137 #else 138 #define logo_mono ((const struct linux_logo *)NULL) 139 #endif 140 141 /* 142 * Color conversion 143 */ 144 145 static u16 convert_xrgb8888_to_rgb565(u32 pix) 146 { 147 return ((pix & 0x00F80000) >> 8) | 148 ((pix & 0x0000FC00) >> 5) | 149 ((pix & 0x000000F8) >> 3); 150 } 151 152 static 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 } 159 160 static u16 convert_xrgb8888_to_xrgb1555(u32 pix) 161 { 162 return ((pix & 0x00f80000) >> 9) | 163 ((pix & 0x0000f800) >> 6) | 164 ((pix & 0x000000f8) >> 3); 165 } 166 167 static 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 } 174 175 static u32 convert_xrgb8888_to_argb8888(u32 pix) 176 { 177 return pix | GENMASK(31, 24); /* fill alpha bits */ 178 } 179 180 static 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 } 187 188 static 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 } 195 196 static 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 } 203 204 static 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 static u32 convert_xrgb8888_to_abgr2101010(u32 pix) 213 { 214 pix = ((pix & 0x00FF0000) >> 14) | 215 ((pix & 0x0000FF00) << 4) | 216 ((pix & 0x000000FF) << 22); 217 return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03); 218 } 219 220 /* 221 * convert_from_xrgb8888 - convert one pixel from xrgb8888 to the desired format 222 * @color: input color, in xrgb8888 format 223 * @format: output format 224 * 225 * Returns: 226 * Color in the format specified, casted to u32. 227 * Or 0 if the format is not supported. 228 */ 229 static u32 convert_from_xrgb8888(u32 color, u32 format) 230 { 231 switch (format) { 232 case DRM_FORMAT_RGB565: 233 return convert_xrgb8888_to_rgb565(color); 234 case DRM_FORMAT_RGBA5551: 235 return convert_xrgb8888_to_rgba5551(color); 236 case DRM_FORMAT_XRGB1555: 237 return convert_xrgb8888_to_xrgb1555(color); 238 case DRM_FORMAT_ARGB1555: 239 return convert_xrgb8888_to_argb1555(color); 240 case DRM_FORMAT_RGB888: 241 case DRM_FORMAT_XRGB8888: 242 return color; 243 case DRM_FORMAT_ARGB8888: 244 return convert_xrgb8888_to_argb8888(color); 245 case DRM_FORMAT_XBGR8888: 246 return convert_xrgb8888_to_xbgr8888(color); 247 case DRM_FORMAT_ABGR8888: 248 return convert_xrgb8888_to_abgr8888(color); 249 case DRM_FORMAT_XRGB2101010: 250 return convert_xrgb8888_to_xrgb2101010(color); 251 case DRM_FORMAT_ARGB2101010: 252 return convert_xrgb8888_to_argb2101010(color); 253 case DRM_FORMAT_ABGR2101010: 254 return convert_xrgb8888_to_abgr2101010(color); 255 default: 256 WARN_ONCE(1, "Can't convert to %p4cc\n", &format); 257 return 0; 258 } 259 } 260 261 /* 262 * Blit & Fill 263 */ 264 /* check if the pixel at coord x,y is 1 (foreground) or 0 (background) */ 265 static bool drm_panic_is_pixel_fg(const u8 *sbuf8, unsigned int spitch, int x, int y) 266 { 267 return (sbuf8[(y * spitch) + x / 8] & (0x80 >> (x % 8))) != 0; 268 } 269 270 static void drm_panic_blit16(struct iosys_map *dmap, unsigned int dpitch, 271 const u8 *sbuf8, unsigned int spitch, 272 unsigned int height, unsigned int width, 273 unsigned int scale, u16 fg16) 274 { 275 unsigned int y, x; 276 277 for (y = 0; y < height; y++) 278 for (x = 0; x < width; x++) 279 if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) 280 iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, fg16); 281 } 282 283 static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch, 284 const u8 *sbuf8, unsigned int spitch, 285 unsigned int height, unsigned int width, 286 unsigned int scale, u32 fg32) 287 { 288 unsigned int y, x; 289 290 for (y = 0; y < height; y++) { 291 for (x = 0; x < width; x++) { 292 u32 off = y * dpitch + x * 3; 293 294 if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) { 295 /* write blue-green-red to output in little endianness */ 296 iosys_map_wr(dmap, off, u8, (fg32 & 0x000000FF) >> 0); 297 iosys_map_wr(dmap, off + 1, u8, (fg32 & 0x0000FF00) >> 8); 298 iosys_map_wr(dmap, off + 2, u8, (fg32 & 0x00FF0000) >> 16); 299 } 300 } 301 } 302 } 303 304 static void drm_panic_blit32(struct iosys_map *dmap, unsigned int dpitch, 305 const u8 *sbuf8, unsigned int spitch, 306 unsigned int height, unsigned int width, 307 unsigned int scale, u32 fg32) 308 { 309 unsigned int y, x; 310 311 for (y = 0; y < height; y++) 312 for (x = 0; x < width; x++) 313 if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) 314 iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, fg32); 315 } 316 317 static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip, 318 const u8 *sbuf8, unsigned int spitch, unsigned int scale, 319 u32 fg_color) 320 { 321 unsigned int y, x; 322 323 for (y = 0; y < drm_rect_height(clip); y++) 324 for (x = 0; x < drm_rect_width(clip); x++) 325 if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) 326 sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color); 327 } 328 329 /* 330 * drm_panic_blit - convert a monochrome image to a linear framebuffer 331 * @sb: destination scanout buffer 332 * @clip: destination rectangle 333 * @sbuf8: source buffer, in monochrome format, 8 pixels per byte. 334 * @spitch: source pitch in bytes 335 * @scale: integer scale, source buffer is scale time smaller than destination 336 * rectangle 337 * @fg_color: foreground color, in destination format 338 * 339 * This can be used to draw a font character, which is a monochrome image, to a 340 * framebuffer in other supported format. 341 */ 342 static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip, 343 const u8 *sbuf8, unsigned int spitch, 344 unsigned int scale, u32 fg_color) 345 346 { 347 struct iosys_map map; 348 349 if (sb->set_pixel) 350 return drm_panic_blit_pixel(sb, clip, sbuf8, spitch, scale, fg_color); 351 352 map = sb->map[0]; 353 iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]); 354 355 switch (sb->format->cpp[0]) { 356 case 2: 357 drm_panic_blit16(&map, sb->pitch[0], sbuf8, spitch, 358 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color); 359 break; 360 case 3: 361 drm_panic_blit24(&map, sb->pitch[0], sbuf8, spitch, 362 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color); 363 break; 364 case 4: 365 drm_panic_blit32(&map, sb->pitch[0], sbuf8, spitch, 366 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color); 367 break; 368 default: 369 WARN_ONCE(1, "Can't blit with pixel width %d\n", sb->format->cpp[0]); 370 } 371 } 372 373 static void drm_panic_fill16(struct iosys_map *dmap, unsigned int dpitch, 374 unsigned int height, unsigned int width, 375 u16 color) 376 { 377 unsigned int y, x; 378 379 for (y = 0; y < height; y++) 380 for (x = 0; x < width; x++) 381 iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, color); 382 } 383 384 static void drm_panic_fill24(struct iosys_map *dmap, unsigned int dpitch, 385 unsigned int height, unsigned int width, 386 u32 color) 387 { 388 unsigned int y, x; 389 390 for (y = 0; y < height; y++) { 391 for (x = 0; x < width; x++) { 392 unsigned int off = y * dpitch + x * 3; 393 394 /* write blue-green-red to output in little endianness */ 395 iosys_map_wr(dmap, off, u8, (color & 0x000000FF) >> 0); 396 iosys_map_wr(dmap, off + 1, u8, (color & 0x0000FF00) >> 8); 397 iosys_map_wr(dmap, off + 2, u8, (color & 0x00FF0000) >> 16); 398 } 399 } 400 } 401 402 static void drm_panic_fill32(struct iosys_map *dmap, unsigned int dpitch, 403 unsigned int height, unsigned int width, 404 u32 color) 405 { 406 unsigned int y, x; 407 408 for (y = 0; y < height; y++) 409 for (x = 0; x < width; x++) 410 iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, color); 411 } 412 413 static void drm_panic_fill_pixel(struct drm_scanout_buffer *sb, 414 struct drm_rect *clip, 415 u32 color) 416 { 417 unsigned int y, x; 418 419 for (y = 0; y < drm_rect_height(clip); y++) 420 for (x = 0; x < drm_rect_width(clip); x++) 421 sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, color); 422 } 423 424 /* 425 * drm_panic_fill - Fill a rectangle with a color 426 * @sb: destination scanout buffer 427 * @clip: destination rectangle 428 * @color: foreground color, in destination format 429 * 430 * Fill a rectangle with a color, in a linear framebuffer. 431 */ 432 static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip, 433 u32 color) 434 { 435 struct iosys_map map; 436 437 if (sb->set_pixel) 438 return drm_panic_fill_pixel(sb, clip, color); 439 440 map = sb->map[0]; 441 iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]); 442 443 switch (sb->format->cpp[0]) { 444 case 2: 445 drm_panic_fill16(&map, sb->pitch[0], drm_rect_height(clip), 446 drm_rect_width(clip), color); 447 break; 448 case 3: 449 drm_panic_fill24(&map, sb->pitch[0], drm_rect_height(clip), 450 drm_rect_width(clip), color); 451 break; 452 case 4: 453 drm_panic_fill32(&map, sb->pitch[0], drm_rect_height(clip), 454 drm_rect_width(clip), color); 455 break; 456 default: 457 WARN_ONCE(1, "Can't fill with pixel width %d\n", sb->format->cpp[0]); 458 } 459 } 460 461 static const u8 *get_char_bitmap(const struct font_desc *font, char c, size_t font_pitch) 462 { 463 return font->data + (c * font->height) * font_pitch; 464 } 465 466 static unsigned int get_max_line_len(const struct drm_panic_line *lines, int len) 467 { 468 int i; 469 unsigned int max = 0; 470 471 for (i = 0; i < len; i++) 472 max = max(lines[i].len, max); 473 return max; 474 } 475 476 /* 477 * Draw a text in a rectangle on a framebuffer. The text is truncated if it overflows the rectangle 478 */ 479 static void draw_txt_rectangle(struct drm_scanout_buffer *sb, 480 const struct font_desc *font, 481 const struct drm_panic_line *msg, 482 unsigned int msg_lines, 483 bool centered, 484 struct drm_rect *clip, 485 u32 color) 486 { 487 int i, j; 488 const u8 *src; 489 size_t font_pitch = DIV_ROUND_UP(font->width, 8); 490 struct drm_rect rec; 491 492 msg_lines = min(msg_lines, drm_rect_height(clip) / font->height); 493 for (i = 0; i < msg_lines; i++) { 494 size_t line_len = min(msg[i].len, drm_rect_width(clip) / font->width); 495 496 rec.y1 = clip->y1 + i * font->height; 497 rec.y2 = rec.y1 + font->height; 498 rec.x1 = clip->x1; 499 500 if (centered) 501 rec.x1 += (drm_rect_width(clip) - (line_len * font->width)) / 2; 502 503 for (j = 0; j < line_len; j++) { 504 src = get_char_bitmap(font, msg[i].txt[j], font_pitch); 505 rec.x2 = rec.x1 + font->width; 506 drm_panic_blit(sb, &rec, src, font_pitch, 1, color); 507 rec.x1 += font->width; 508 } 509 } 510 } 511 512 static void drm_panic_logo_rect(struct drm_rect *rect, const struct font_desc *font) 513 { 514 if (logo_mono) { 515 drm_rect_init(rect, 0, 0, logo_mono->width, logo_mono->height); 516 } else { 517 int logo_width = get_max_line_len(logo_ascii, logo_ascii_lines) * font->width; 518 519 drm_rect_init(rect, 0, 0, logo_width, logo_ascii_lines * font->height); 520 } 521 } 522 523 static void drm_panic_logo_draw(struct drm_scanout_buffer *sb, struct drm_rect *rect, 524 const struct font_desc *font, u32 fg_color) 525 { 526 if (logo_mono) 527 drm_panic_blit(sb, rect, logo_mono->data, 528 DIV_ROUND_UP(drm_rect_width(rect), 8), 1, fg_color); 529 else 530 draw_txt_rectangle(sb, font, logo_ascii, logo_ascii_lines, false, rect, 531 fg_color); 532 } 533 534 static void draw_panic_static_user(struct drm_scanout_buffer *sb) 535 { 536 u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format); 537 u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format); 538 const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL); 539 struct drm_rect r_screen, r_logo, r_msg; 540 unsigned int msg_width, msg_height; 541 542 if (!font) 543 return; 544 545 r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height); 546 drm_panic_logo_rect(&r_logo, font); 547 548 msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width); 549 msg_height = min(panic_msg_lines * font->height, sb->height); 550 r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height); 551 552 /* Center the panic message */ 553 drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, (sb->height - r_msg.y2) / 2); 554 555 /* Fill with the background color, and draw text on top */ 556 drm_panic_fill(sb, &r_screen, bg_color); 557 558 if (!drm_rect_overlap(&r_logo, &r_msg)) 559 drm_panic_logo_draw(sb, &r_logo, font, fg_color); 560 561 draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color); 562 } 563 564 /* 565 * Draw one line of kmsg, and handle wrapping if it won't fit in the screen width. 566 * Return the y-offset of the next line. 567 */ 568 static int draw_line_with_wrap(struct drm_scanout_buffer *sb, const struct font_desc *font, 569 struct drm_panic_line *line, int yoffset, u32 fg_color) 570 { 571 int chars_per_row = sb->width / font->width; 572 struct drm_rect r_txt = DRM_RECT_INIT(0, yoffset, sb->width, sb->height); 573 struct drm_panic_line line_wrap; 574 575 if (line->len > chars_per_row) { 576 line_wrap.len = line->len % chars_per_row; 577 line_wrap.txt = line->txt + line->len - line_wrap.len; 578 draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color); 579 r_txt.y1 -= font->height; 580 if (r_txt.y1 < 0) 581 return r_txt.y1; 582 while (line_wrap.txt > line->txt) { 583 line_wrap.txt -= chars_per_row; 584 line_wrap.len = chars_per_row; 585 draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color); 586 r_txt.y1 -= font->height; 587 if (r_txt.y1 < 0) 588 return r_txt.y1; 589 } 590 } else { 591 draw_txt_rectangle(sb, font, line, 1, false, &r_txt, fg_color); 592 r_txt.y1 -= font->height; 593 } 594 return r_txt.y1; 595 } 596 597 /* 598 * Draw the kmsg buffer to the screen, starting from the youngest message at the bottom, 599 * and going up until reaching the top of the screen. 600 */ 601 static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb) 602 { 603 u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format); 604 u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format); 605 const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL); 606 struct drm_rect r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height); 607 struct kmsg_dump_iter iter; 608 char kmsg_buf[512]; 609 size_t kmsg_len; 610 struct drm_panic_line line; 611 int yoffset; 612 613 if (!font) 614 return; 615 616 yoffset = sb->height - font->height - (sb->height % font->height) / 2; 617 618 /* Fill with the background color, and draw text on top */ 619 drm_panic_fill(sb, &r_screen, bg_color); 620 621 kmsg_dump_rewind(&iter); 622 while (kmsg_dump_get_buffer(&iter, false, kmsg_buf, sizeof(kmsg_buf), &kmsg_len)) { 623 char *start; 624 char *end; 625 626 /* ignore terminating NUL and newline */ 627 start = kmsg_buf + kmsg_len - 2; 628 end = kmsg_buf + kmsg_len - 1; 629 while (start > kmsg_buf && yoffset >= 0) { 630 while (start > kmsg_buf && *start != '\n') 631 start--; 632 /* don't count the newline character */ 633 line.txt = start + (start == kmsg_buf ? 0 : 1); 634 line.len = end - line.txt; 635 636 yoffset = draw_line_with_wrap(sb, font, &line, yoffset, fg_color); 637 end = start; 638 start--; 639 } 640 } 641 } 642 643 #if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE) 644 /* 645 * It is unwise to allocate memory in the panic callback, so the buffers are 646 * pre-allocated. Only 2 buffers and the zlib workspace are needed. 647 * Two buffers are enough, using the following buffer usage: 648 * 1) kmsg messages are dumped in buffer1 649 * 2) kmsg is zlib-compressed into buffer2 650 * 3) compressed kmsg is encoded as QR-code Numeric stream in buffer1 651 * 4) QR-code image is generated in buffer2 652 * The Max QR code size is V40, 177x177, 4071 bytes for image, 2956 bytes for 653 * data segments. 654 * 655 * Typically, ~7500 bytes of kmsg, are compressed into 2800 bytes, which fits in 656 * a V40 QR-code (177x177). 657 * 658 * If CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL is not set, the kmsg data will be put 659 * directly in the QR code. 660 * 1) kmsg messages are dumped in buffer1 661 * 2) kmsg message is encoded as byte stream in buffer2 662 * 3) QR-code image is generated in buffer1 663 */ 664 665 static uint panic_qr_version = CONFIG_DRM_PANIC_SCREEN_QR_VERSION; 666 module_param(panic_qr_version, uint, 0644); 667 MODULE_PARM_DESC(panic_qr_version, "maximum version (size) of the QR code"); 668 669 #define MAX_QR_DATA 2956 670 #define MAX_ZLIB_RATIO 3 671 #define QR_BUFFER1_SIZE (MAX_ZLIB_RATIO * MAX_QR_DATA) /* Must also be > 4071 */ 672 #define QR_BUFFER2_SIZE 4096 673 #define QR_MARGIN 4 /* 4 modules of foreground color around the qr code */ 674 675 /* Compression parameters */ 676 #define COMPR_LEVEL 6 677 #define WINDOW_BITS 12 678 #define MEM_LEVEL 4 679 680 static char *qrbuf1; 681 static char *qrbuf2; 682 static struct z_stream_s stream; 683 684 static void __init drm_panic_qr_init(void) 685 { 686 qrbuf1 = kmalloc(QR_BUFFER1_SIZE, GFP_KERNEL); 687 qrbuf2 = kmalloc(QR_BUFFER2_SIZE, GFP_KERNEL); 688 stream.workspace = kmalloc(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL), 689 GFP_KERNEL); 690 } 691 692 static void drm_panic_qr_exit(void) 693 { 694 kfree(qrbuf1); 695 qrbuf1 = NULL; 696 kfree(qrbuf2); 697 qrbuf2 = NULL; 698 kfree(stream.workspace); 699 stream.workspace = NULL; 700 } 701 702 extern size_t drm_panic_qr_max_data_size(u8 version, size_t url_len); 703 704 extern u8 drm_panic_qr_generate(const char *url, u8 *data, size_t data_len, size_t data_size, 705 u8 *tmp, size_t tmp_size); 706 707 static int drm_panic_get_qr_code_url(u8 **qr_image) 708 { 709 struct kmsg_dump_iter iter; 710 char url[256]; 711 size_t kmsg_len, max_kmsg_size; 712 char *kmsg; 713 int max_qr_data_size, url_len; 714 715 url_len = snprintf(url, sizeof(url), CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL "?a=%s&v=%s&zl=", 716 utsname()->machine, utsname()->release); 717 718 max_qr_data_size = drm_panic_qr_max_data_size(panic_qr_version, url_len); 719 max_kmsg_size = min(MAX_ZLIB_RATIO * max_qr_data_size, QR_BUFFER1_SIZE); 720 721 /* get kmsg to buffer 1 */ 722 kmsg_dump_rewind(&iter); 723 kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len); 724 725 if (!kmsg_len) 726 return -ENODATA; 727 kmsg = qrbuf1; 728 729 try_again: 730 if (zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS, 731 MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK) 732 return -EINVAL; 733 734 stream.next_in = kmsg; 735 stream.avail_in = kmsg_len; 736 stream.total_in = 0; 737 stream.next_out = qrbuf2; 738 stream.avail_out = QR_BUFFER2_SIZE; 739 stream.total_out = 0; 740 741 if (zlib_deflate(&stream, Z_FINISH) != Z_STREAM_END) 742 return -EINVAL; 743 744 if (zlib_deflateEnd(&stream) != Z_OK) 745 return -EINVAL; 746 747 if (stream.total_out > max_qr_data_size) { 748 /* too much data for the QR code, so skip the first line and try again */ 749 kmsg = strchr(kmsg, '\n'); 750 if (!kmsg) 751 return -EINVAL; 752 /* skip the first \n */ 753 kmsg += 1; 754 kmsg_len = strlen(kmsg); 755 goto try_again; 756 } 757 *qr_image = qrbuf2; 758 759 /* generate qr code image in buffer2 */ 760 return drm_panic_qr_generate(url, qrbuf2, stream.total_out, QR_BUFFER2_SIZE, 761 qrbuf1, QR_BUFFER1_SIZE); 762 } 763 764 static int drm_panic_get_qr_code_raw(u8 **qr_image) 765 { 766 struct kmsg_dump_iter iter; 767 size_t kmsg_len; 768 size_t max_kmsg_size = min(drm_panic_qr_max_data_size(panic_qr_version, 0), 769 QR_BUFFER1_SIZE); 770 771 kmsg_dump_rewind(&iter); 772 kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len); 773 if (!kmsg_len) 774 return -ENODATA; 775 776 *qr_image = qrbuf1; 777 return drm_panic_qr_generate(NULL, qrbuf1, kmsg_len, QR_BUFFER1_SIZE, 778 qrbuf2, QR_BUFFER2_SIZE); 779 } 780 781 static int drm_panic_get_qr_code(u8 **qr_image) 782 { 783 if (strlen(CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL) > 0) 784 return drm_panic_get_qr_code_url(qr_image); 785 else 786 return drm_panic_get_qr_code_raw(qr_image); 787 } 788 789 /* 790 * Draw the panic message at the center of the screen, with a QR Code 791 */ 792 static int _draw_panic_static_qr_code(struct drm_scanout_buffer *sb) 793 { 794 u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format); 795 u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format); 796 const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL); 797 struct drm_rect r_screen, r_logo, r_msg, r_qr, r_qr_canvas; 798 unsigned int max_qr_size, scale; 799 unsigned int msg_width, msg_height; 800 int qr_width, qr_canvas_width, qr_pitch, v_margin; 801 u8 *qr_image; 802 803 if (!font || !qrbuf1 || !qrbuf2 || !stream.workspace) 804 return -ENOMEM; 805 806 r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height); 807 808 drm_panic_logo_rect(&r_logo, font); 809 810 msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width); 811 msg_height = min(panic_msg_lines * font->height, sb->height); 812 r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height); 813 814 max_qr_size = min(3 * sb->width / 4, 3 * sb->height / 4); 815 816 qr_width = drm_panic_get_qr_code(&qr_image); 817 if (qr_width <= 0) 818 return -ENOSPC; 819 820 qr_canvas_width = qr_width + QR_MARGIN * 2; 821 scale = max_qr_size / qr_canvas_width; 822 /* QR code is not readable if not scaled at least by 2 */ 823 if (scale < 2) 824 return -ENOSPC; 825 826 pr_debug("QR width %d and scale %d\n", qr_width, scale); 827 r_qr_canvas = DRM_RECT_INIT(0, 0, qr_canvas_width * scale, qr_canvas_width * scale); 828 829 v_margin = (sb->height - drm_rect_height(&r_qr_canvas) - drm_rect_height(&r_msg)) / 5; 830 831 drm_rect_translate(&r_qr_canvas, (sb->width - r_qr_canvas.x2) / 2, 2 * v_margin); 832 r_qr = DRM_RECT_INIT(r_qr_canvas.x1 + QR_MARGIN * scale, r_qr_canvas.y1 + QR_MARGIN * scale, 833 qr_width * scale, qr_width * scale); 834 835 /* Center the panic message */ 836 drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, 837 3 * v_margin + drm_rect_height(&r_qr_canvas)); 838 839 /* Fill with the background color, and draw text on top */ 840 drm_panic_fill(sb, &r_screen, bg_color); 841 842 if (!drm_rect_overlap(&r_logo, &r_msg) && !drm_rect_overlap(&r_logo, &r_qr)) 843 drm_panic_logo_draw(sb, &r_logo, font, fg_color); 844 845 draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color); 846 847 /* Draw the qr code */ 848 qr_pitch = DIV_ROUND_UP(qr_width, 8); 849 drm_panic_fill(sb, &r_qr_canvas, fg_color); 850 drm_panic_fill(sb, &r_qr, bg_color); 851 drm_panic_blit(sb, &r_qr, qr_image, qr_pitch, scale, fg_color); 852 return 0; 853 } 854 855 static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb) 856 { 857 if (_draw_panic_static_qr_code(sb)) 858 draw_panic_static_user(sb); 859 } 860 #else 861 static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb) 862 { 863 draw_panic_static_user(sb); 864 } 865 866 static void drm_panic_qr_init(void) {}; 867 static void drm_panic_qr_exit(void) {}; 868 #endif 869 870 /* 871 * drm_panic_is_format_supported() 872 * @format: a fourcc color code 873 * Returns: true if supported, false otherwise. 874 * 875 * Check if drm_panic will be able to use this color format. 876 */ 877 static bool drm_panic_is_format_supported(const struct drm_format_info *format) 878 { 879 if (format->num_planes != 1) 880 return false; 881 return convert_from_xrgb8888(0xffffff, format->format) != 0; 882 } 883 884 static void draw_panic_dispatch(struct drm_scanout_buffer *sb) 885 { 886 if (!strcmp(drm_panic_screen, "kmsg")) { 887 draw_panic_static_kmsg(sb); 888 } else if (!strcmp(drm_panic_screen, "qr_code")) { 889 draw_panic_static_qr_code(sb); 890 } else { 891 draw_panic_static_user(sb); 892 } 893 } 894 895 static void drm_panic_set_description(const char *description) 896 { 897 u32 len; 898 899 if (description) { 900 struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1]; 901 902 desc_line->txt = description; 903 len = strlen(description); 904 /* ignore the last newline character */ 905 if (len && description[len - 1] == '\n') 906 len -= 1; 907 desc_line->len = len; 908 } 909 } 910 911 static void drm_panic_clear_description(void) 912 { 913 struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1]; 914 915 desc_line->len = 0; 916 desc_line->txt = NULL; 917 } 918 919 static void draw_panic_plane(struct drm_plane *plane, const char *description) 920 { 921 struct drm_scanout_buffer sb = { }; 922 int ret; 923 unsigned long flags; 924 925 if (!drm_panic_trylock(plane->dev, flags)) 926 return; 927 928 drm_panic_set_description(description); 929 930 ret = plane->helper_private->get_scanout_buffer(plane, &sb); 931 932 if (!ret && drm_panic_is_format_supported(sb.format)) { 933 draw_panic_dispatch(&sb); 934 if (plane->helper_private->panic_flush) 935 plane->helper_private->panic_flush(plane); 936 } 937 drm_panic_clear_description(); 938 drm_panic_unlock(plane->dev, flags); 939 } 940 941 static struct drm_plane *to_drm_plane(struct kmsg_dumper *kd) 942 { 943 return container_of(kd, struct drm_plane, kmsg_panic); 944 } 945 946 static void drm_panic(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detail) 947 { 948 struct drm_plane *plane = to_drm_plane(dumper); 949 950 if (detail->reason == KMSG_DUMP_PANIC) 951 draw_panic_plane(plane, detail->description); 952 } 953 954 955 /* 956 * DEBUG FS, This is currently unsafe. 957 * Create one file per plane, so it's possible to debug one plane at a time. 958 * TODO: It would be better to emulate an NMI context. 959 */ 960 #ifdef CONFIG_DRM_PANIC_DEBUG 961 #include <linux/debugfs.h> 962 963 static ssize_t debugfs_trigger_write(struct file *file, const char __user *user_buf, 964 size_t count, loff_t *ppos) 965 { 966 bool run; 967 968 if (kstrtobool_from_user(user_buf, count, &run) == 0 && run) { 969 struct drm_plane *plane = file->private_data; 970 971 draw_panic_plane(plane, "Test from debugfs"); 972 } 973 return count; 974 } 975 976 static const struct file_operations dbg_drm_panic_ops = { 977 .owner = THIS_MODULE, 978 .write = debugfs_trigger_write, 979 .open = simple_open, 980 }; 981 982 static void debugfs_register_plane(struct drm_plane *plane, int index) 983 { 984 char fname[32]; 985 986 snprintf(fname, 32, "drm_panic_plane_%d", index); 987 debugfs_create_file(fname, 0200, plane->dev->debugfs_root, 988 plane, &dbg_drm_panic_ops); 989 } 990 #else 991 static void debugfs_register_plane(struct drm_plane *plane, int index) {} 992 #endif /* CONFIG_DRM_PANIC_DEBUG */ 993 994 /** 995 * drm_panic_is_enabled 996 * @dev: the drm device that may supports drm_panic 997 * 998 * returns true if the drm device supports drm_panic 999 */ 1000 bool drm_panic_is_enabled(struct drm_device *dev) 1001 { 1002 struct drm_plane *plane; 1003 1004 if (!dev->mode_config.num_total_plane) 1005 return false; 1006 1007 drm_for_each_plane(plane, dev) 1008 if (plane->helper_private && plane->helper_private->get_scanout_buffer) 1009 return true; 1010 return false; 1011 } 1012 EXPORT_SYMBOL(drm_panic_is_enabled); 1013 1014 /** 1015 * drm_panic_register() - Initialize DRM panic for a device 1016 * @dev: the drm device on which the panic screen will be displayed. 1017 */ 1018 void drm_panic_register(struct drm_device *dev) 1019 { 1020 struct drm_plane *plane; 1021 int registered_plane = 0; 1022 1023 if (!dev->mode_config.num_total_plane) 1024 return; 1025 1026 drm_for_each_plane(plane, dev) { 1027 if (!plane->helper_private || !plane->helper_private->get_scanout_buffer) 1028 continue; 1029 plane->kmsg_panic.dump = drm_panic; 1030 plane->kmsg_panic.max_reason = KMSG_DUMP_PANIC; 1031 if (kmsg_dump_register(&plane->kmsg_panic)) 1032 drm_warn(dev, "Failed to register panic handler\n"); 1033 else { 1034 debugfs_register_plane(plane, registered_plane); 1035 registered_plane++; 1036 } 1037 } 1038 if (registered_plane) 1039 drm_info(dev, "Registered %d planes with drm panic\n", registered_plane); 1040 } 1041 1042 /** 1043 * drm_panic_unregister() 1044 * @dev: the drm device previously registered. 1045 */ 1046 void drm_panic_unregister(struct drm_device *dev) 1047 { 1048 struct drm_plane *plane; 1049 1050 if (!dev->mode_config.num_total_plane) 1051 return; 1052 1053 drm_for_each_plane(plane, dev) { 1054 if (!plane->helper_private || !plane->helper_private->get_scanout_buffer) 1055 continue; 1056 kmsg_dump_unregister(&plane->kmsg_panic); 1057 } 1058 } 1059 1060 /** 1061 * drm_panic_init() - initialize DRM panic. 1062 */ 1063 void __init drm_panic_init(void) 1064 { 1065 drm_panic_qr_init(); 1066 } 1067 1068 /** 1069 * drm_panic_exit() - Free the resources taken by drm_panic_exit() 1070 */ 1071 void drm_panic_exit(void) 1072 { 1073 drm_panic_qr_exit(); 1074 } 1075