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/export.h> 10 #include <linux/font.h> 11 #include <linux/highmem.h> 12 #include <linux/init.h> 13 #include <linux/iosys-map.h> 14 #include <linux/kdebug.h> 15 #include <linux/kmsg_dump.h> 16 #include <linux/linux_logo.h> 17 #include <linux/list.h> 18 #include <linux/math.h> 19 #include <linux/module.h> 20 #include <linux/overflow.h> 21 #include <linux/printk.h> 22 #include <linux/types.h> 23 #include <linux/utsname.h> 24 #include <linux/zlib.h> 25 26 #include <drm/drm_drv.h> 27 #include <drm/drm_fourcc.h> 28 #include <drm/drm_framebuffer.h> 29 #include <drm/drm_modeset_helper_vtables.h> 30 #include <drm/drm_panic.h> 31 #include <drm/drm_plane.h> 32 #include <drm/drm_print.h> 33 #include <drm/drm_rect.h> 34 35 #include "drm_crtc_internal.h" 36 #include "drm_draw_internal.h" 37 38 MODULE_AUTHOR("Jocelyn Falempe"); 39 MODULE_DESCRIPTION("DRM panic handler"); 40 MODULE_LICENSE("GPL"); 41 42 static char drm_panic_screen[16] = CONFIG_DRM_PANIC_SCREEN; 43 module_param_string(panic_screen, drm_panic_screen, sizeof(drm_panic_screen), 0644); 44 MODULE_PARM_DESC(panic_screen, 45 "Choose what will be displayed by drm_panic, 'user' or 'kmsg' [default=" 46 CONFIG_DRM_PANIC_SCREEN "]"); 47 48 /** 49 * DOC: overview 50 * 51 * To enable DRM panic for a driver, the primary plane must implement a 52 * &drm_plane_helper_funcs.get_scanout_buffer helper function. It is then 53 * automatically registered to the drm panic handler. 54 * When a panic occurs, the &drm_plane_helper_funcs.get_scanout_buffer will be 55 * called, and the driver can provide a framebuffer so the panic handler can 56 * draw the panic screen on it. Currently only linear buffer and a few color 57 * formats are supported. 58 * Optionally the driver can also provide a &drm_plane_helper_funcs.panic_flush 59 * callback, that will be called after that, to send additional commands to the 60 * hardware to make the scanout buffer visible. 61 */ 62 63 /* 64 * This module displays a user friendly message on screen when a kernel panic 65 * occurs. This is conflicting with fbcon, so you can only enable it when fbcon 66 * is disabled. 67 * It's intended for end-user, so have minimal technical/debug information. 68 * 69 * Implementation details: 70 * 71 * It is a panic handler, so it can't take lock, allocate memory, run tasks/irq, 72 * or attempt to sleep. It's a best effort, and it may not be able to display 73 * the message in all situations (like if the panic occurs in the middle of a 74 * modesetting). 75 * It will display only one static frame, so performance optimizations are low 76 * priority as the machine is already in an unusable state. 77 */ 78 79 struct drm_panic_line { 80 u32 len; 81 const char *txt; 82 }; 83 84 #define PANIC_LINE(s) {.len = sizeof(s) - 1, .txt = s} 85 86 static struct drm_panic_line panic_msg[] = { 87 PANIC_LINE("KERNEL PANIC!"), 88 PANIC_LINE(""), 89 PANIC_LINE("Please reboot your computer."), 90 PANIC_LINE(""), 91 PANIC_LINE(""), /* will be replaced by the panic description */ 92 }; 93 94 static const size_t panic_msg_lines = ARRAY_SIZE(panic_msg); 95 96 static const struct drm_panic_line logo_ascii[] = { 97 PANIC_LINE(" .--. _"), 98 PANIC_LINE(" |o_o | | |"), 99 PANIC_LINE(" |:_/ | | |"), 100 PANIC_LINE(" // \\ \\ |_|"), 101 PANIC_LINE(" (| | ) _"), 102 PANIC_LINE(" /'\\_ _/`\\ (_)"), 103 PANIC_LINE(" \\___)=(___/"), 104 }; 105 106 static const size_t logo_ascii_lines = ARRAY_SIZE(logo_ascii); 107 108 #if defined(CONFIG_LOGO) && !defined(MODULE) 109 static const struct linux_logo *logo_mono; 110 111 static int drm_panic_setup_logo(void) 112 { 113 const struct linux_logo *logo = fb_find_logo(1); 114 const unsigned char *logo_data; 115 struct linux_logo *logo_dup; 116 117 if (!logo || logo->type != LINUX_LOGO_MONO) 118 return 0; 119 120 /* The logo is __init, so we must make a copy for later use */ 121 logo_data = kmemdup(logo->data, 122 size_mul(DIV_ROUND_UP(logo->width, BITS_PER_BYTE), logo->height), 123 GFP_KERNEL); 124 if (!logo_data) 125 return -ENOMEM; 126 127 logo_dup = kmemdup(logo, sizeof(*logo), GFP_KERNEL); 128 if (!logo_dup) { 129 kfree(logo_data); 130 return -ENOMEM; 131 } 132 133 logo_dup->data = logo_data; 134 logo_mono = logo_dup; 135 136 return 0; 137 } 138 139 device_initcall(drm_panic_setup_logo); 140 #else 141 #define logo_mono ((const struct linux_logo *)NULL) 142 #endif 143 144 /* 145 * Blit & Fill functions 146 */ 147 static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip, 148 const u8 *sbuf8, unsigned int spitch, unsigned int scale, 149 u32 fg_color) 150 { 151 unsigned int y, x; 152 153 for (y = 0; y < drm_rect_height(clip); y++) 154 for (x = 0; x < drm_rect_width(clip); x++) 155 if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) 156 sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color); 157 } 158 159 static void drm_panic_write_pixel16(void *vaddr, unsigned int offset, u16 color) 160 { 161 u16 *p = vaddr + offset; 162 163 *p = color; 164 } 165 166 static void drm_panic_write_pixel24(void *vaddr, unsigned int offset, u32 color) 167 { 168 u8 *p = vaddr + offset; 169 170 *p++ = color & 0xff; 171 color >>= 8; 172 *p++ = color & 0xff; 173 color >>= 8; 174 *p = color & 0xff; 175 } 176 177 /* 178 * Special case if the pixel crosses page boundaries 179 */ 180 static void drm_panic_write_pixel24_xpage(void *vaddr, struct page *next_page, 181 unsigned int offset, u32 color) 182 { 183 u8 *vaddr2; 184 u8 *p = vaddr + offset; 185 186 vaddr2 = kmap_local_page_try_from_panic(next_page); 187 188 *p++ = color & 0xff; 189 color >>= 8; 190 191 if (offset == PAGE_SIZE - 1) 192 p = vaddr2; 193 194 *p++ = color & 0xff; 195 color >>= 8; 196 197 if (offset == PAGE_SIZE - 2) 198 p = vaddr2; 199 200 *p = color & 0xff; 201 kunmap_local(vaddr2); 202 } 203 204 static void drm_panic_write_pixel32(void *vaddr, unsigned int offset, u32 color) 205 { 206 u32 *p = vaddr + offset; 207 208 *p = color; 209 } 210 211 static void drm_panic_write_pixel(void *vaddr, unsigned int offset, u32 color, unsigned int cpp) 212 { 213 switch (cpp) { 214 case 2: 215 drm_panic_write_pixel16(vaddr, offset, color); 216 break; 217 case 3: 218 drm_panic_write_pixel24(vaddr, offset, color); 219 break; 220 case 4: 221 drm_panic_write_pixel32(vaddr, offset, color); 222 break; 223 default: 224 pr_debug_once("Can't blit with pixel width %d\n", cpp); 225 } 226 } 227 228 /* 229 * The scanout buffer pages are not mapped, so for each pixel, 230 * use kmap_local_page_try_from_panic() to map the page, and write the pixel. 231 * Try to keep the map from the previous pixel, to avoid too much map/unmap. 232 */ 233 static void drm_panic_blit_page(struct page **pages, unsigned int dpitch, 234 unsigned int cpp, const u8 *sbuf8, 235 unsigned int spitch, struct drm_rect *clip, 236 unsigned int scale, u32 fg32) 237 { 238 unsigned int y, x; 239 unsigned int page = ~0; 240 unsigned int height = drm_rect_height(clip); 241 unsigned int width = drm_rect_width(clip); 242 void *vaddr = NULL; 243 244 for (y = 0; y < height; y++) { 245 for (x = 0; x < width; x++) { 246 if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) { 247 unsigned int new_page; 248 unsigned int offset; 249 250 offset = (y + clip->y1) * dpitch + (x + clip->x1) * cpp; 251 new_page = offset >> PAGE_SHIFT; 252 offset = offset % PAGE_SIZE; 253 if (new_page != page) { 254 if (!pages[new_page]) 255 continue; 256 if (vaddr) 257 kunmap_local(vaddr); 258 page = new_page; 259 vaddr = kmap_local_page_try_from_panic(pages[page]); 260 } 261 if (!vaddr) 262 continue; 263 264 // Special case for 24bit, as a pixel might cross page boundaries 265 if (cpp == 3 && offset + 3 > PAGE_SIZE) 266 drm_panic_write_pixel24_xpage(vaddr, pages[page + 1], 267 offset, fg32); 268 else 269 drm_panic_write_pixel(vaddr, offset, fg32, cpp); 270 } 271 } 272 } 273 if (vaddr) 274 kunmap_local(vaddr); 275 } 276 277 /* 278 * drm_panic_blit - convert a monochrome image to a linear framebuffer 279 * @sb: destination scanout buffer 280 * @clip: destination rectangle 281 * @sbuf8: source buffer, in monochrome format, 8 pixels per byte. 282 * @spitch: source pitch in bytes 283 * @scale: integer scale, source buffer is scale time smaller than destination 284 * rectangle 285 * @fg_color: foreground color, in destination format 286 * 287 * This can be used to draw a font character, which is a monochrome image, to a 288 * framebuffer in other supported format. 289 */ 290 static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip, 291 const u8 *sbuf8, unsigned int spitch, 292 unsigned int scale, u32 fg_color) 293 294 { 295 struct iosys_map map; 296 297 if (sb->set_pixel) 298 return drm_panic_blit_pixel(sb, clip, sbuf8, spitch, scale, fg_color); 299 300 if (sb->pages) 301 return drm_panic_blit_page(sb->pages, sb->pitch[0], sb->format->cpp[0], 302 sbuf8, spitch, clip, scale, fg_color); 303 304 map = sb->map[0]; 305 iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]); 306 307 switch (sb->format->cpp[0]) { 308 case 2: 309 drm_draw_blit16(&map, sb->pitch[0], sbuf8, spitch, 310 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color); 311 break; 312 case 3: 313 drm_draw_blit24(&map, sb->pitch[0], sbuf8, spitch, 314 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color); 315 break; 316 case 4: 317 drm_draw_blit32(&map, sb->pitch[0], sbuf8, spitch, 318 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color); 319 break; 320 default: 321 WARN_ONCE(1, "Can't blit with pixel width %d\n", sb->format->cpp[0]); 322 } 323 } 324 325 static void drm_panic_fill_pixel(struct drm_scanout_buffer *sb, 326 struct drm_rect *clip, 327 u32 color) 328 { 329 unsigned int y, x; 330 331 for (y = 0; y < drm_rect_height(clip); y++) 332 for (x = 0; x < drm_rect_width(clip); x++) 333 sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, color); 334 } 335 336 static void drm_panic_fill_page(struct page **pages, unsigned int dpitch, 337 unsigned int cpp, struct drm_rect *clip, 338 u32 color) 339 { 340 unsigned int y, x; 341 unsigned int page = ~0; 342 void *vaddr = NULL; 343 344 for (y = clip->y1; y < clip->y2; y++) { 345 for (x = clip->x1; x < clip->x2; x++) { 346 unsigned int new_page; 347 unsigned int offset; 348 349 offset = y * dpitch + x * cpp; 350 new_page = offset >> PAGE_SHIFT; 351 offset = offset % PAGE_SIZE; 352 if (new_page != page) { 353 if (vaddr) 354 kunmap_local(vaddr); 355 page = new_page; 356 vaddr = kmap_local_page_try_from_panic(pages[page]); 357 } 358 if (!vaddr) 359 continue; 360 361 // Special case for 24bit, as a pixel might cross page boundaries 362 if (cpp == 3 && offset + 3 > PAGE_SIZE) 363 drm_panic_write_pixel24_xpage(vaddr, pages[page + 1], 364 offset, color); 365 else 366 drm_panic_write_pixel(vaddr, offset, color, cpp); 367 } 368 } 369 if (vaddr) 370 kunmap_local(vaddr); 371 } 372 373 /* 374 * drm_panic_fill - Fill a rectangle with a color 375 * @sb: destination scanout buffer 376 * @clip: destination rectangle 377 * @color: foreground color, in destination format 378 * 379 * Fill a rectangle with a color, in a linear framebuffer. 380 */ 381 static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip, 382 u32 color) 383 { 384 struct iosys_map map; 385 386 if (sb->set_pixel) 387 return drm_panic_fill_pixel(sb, clip, color); 388 389 if (sb->pages) 390 return drm_panic_fill_page(sb->pages, sb->pitch[0], sb->format->cpp[0], 391 clip, color); 392 393 map = sb->map[0]; 394 iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]); 395 396 switch (sb->format->cpp[0]) { 397 case 2: 398 drm_draw_fill16(&map, sb->pitch[0], drm_rect_height(clip), 399 drm_rect_width(clip), color); 400 break; 401 case 3: 402 drm_draw_fill24(&map, sb->pitch[0], drm_rect_height(clip), 403 drm_rect_width(clip), color); 404 break; 405 case 4: 406 drm_draw_fill32(&map, sb->pitch[0], drm_rect_height(clip), 407 drm_rect_width(clip), color); 408 break; 409 default: 410 WARN_ONCE(1, "Can't fill with pixel width %d\n", sb->format->cpp[0]); 411 } 412 } 413 414 static unsigned int get_max_line_len(const struct drm_panic_line *lines, int len) 415 { 416 int i; 417 unsigned int max = 0; 418 419 for (i = 0; i < len; i++) 420 max = max(lines[i].len, max); 421 return max; 422 } 423 424 /* 425 * Draw a text in a rectangle on a framebuffer. The text is truncated if it overflows the rectangle 426 */ 427 static void draw_txt_rectangle(struct drm_scanout_buffer *sb, 428 const struct font_desc *font, 429 const struct drm_panic_line *msg, 430 unsigned int msg_lines, 431 bool centered, 432 struct drm_rect *clip, 433 u32 color) 434 { 435 int i, j; 436 const u8 *src; 437 size_t font_pitch = DIV_ROUND_UP(font->width, 8); 438 struct drm_rect rec; 439 440 msg_lines = min(msg_lines, drm_rect_height(clip) / font->height); 441 for (i = 0; i < msg_lines; i++) { 442 size_t line_len = min(msg[i].len, drm_rect_width(clip) / font->width); 443 444 rec.y1 = clip->y1 + i * font->height; 445 rec.y2 = rec.y1 + font->height; 446 rec.x1 = clip->x1; 447 448 if (centered) 449 rec.x1 += (drm_rect_width(clip) - (line_len * font->width)) / 2; 450 451 for (j = 0; j < line_len; j++) { 452 src = drm_draw_get_char_bitmap(font, msg[i].txt[j], font_pitch); 453 rec.x2 = rec.x1 + font->width; 454 drm_panic_blit(sb, &rec, src, font_pitch, 1, color); 455 rec.x1 += font->width; 456 } 457 } 458 } 459 460 static void drm_panic_logo_rect(struct drm_rect *rect, const struct font_desc *font) 461 { 462 if (logo_mono) { 463 drm_rect_init(rect, 0, 0, logo_mono->width, logo_mono->height); 464 } else { 465 int logo_width = get_max_line_len(logo_ascii, logo_ascii_lines) * font->width; 466 467 drm_rect_init(rect, 0, 0, logo_width, logo_ascii_lines * font->height); 468 } 469 } 470 471 static void drm_panic_logo_draw(struct drm_scanout_buffer *sb, struct drm_rect *rect, 472 const struct font_desc *font, u32 fg_color) 473 { 474 if (rect->x2 > sb->width || rect->y2 > sb->height) 475 return; 476 477 if (logo_mono) 478 drm_panic_blit(sb, rect, logo_mono->data, 479 DIV_ROUND_UP(drm_rect_width(rect), 8), 1, fg_color); 480 else 481 draw_txt_rectangle(sb, font, logo_ascii, logo_ascii_lines, false, rect, 482 fg_color); 483 } 484 485 static void draw_panic_static_user(struct drm_scanout_buffer *sb) 486 { 487 u32 fg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, 488 sb->format->format); 489 u32 bg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, 490 sb->format->format); 491 const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL); 492 struct drm_rect r_screen, r_logo, r_msg; 493 unsigned int msg_width, msg_height; 494 495 if (!font) 496 return; 497 498 r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height); 499 drm_panic_logo_rect(&r_logo, font); 500 501 msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width); 502 msg_height = min(panic_msg_lines * font->height, sb->height); 503 r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height); 504 505 /* Center the panic message */ 506 drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, (sb->height - r_msg.y2) / 2); 507 508 /* Fill with the background color, and draw text on top */ 509 drm_panic_fill(sb, &r_screen, bg_color); 510 511 if (!drm_rect_overlap(&r_logo, &r_msg)) 512 drm_panic_logo_draw(sb, &r_logo, font, fg_color); 513 514 draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color); 515 } 516 517 /* 518 * Draw one line of kmsg, and handle wrapping if it won't fit in the screen width. 519 * Return the y-offset of the next line. 520 */ 521 static int draw_line_with_wrap(struct drm_scanout_buffer *sb, const struct font_desc *font, 522 struct drm_panic_line *line, int yoffset, u32 fg_color) 523 { 524 int chars_per_row = sb->width / font->width; 525 struct drm_rect r_txt = DRM_RECT_INIT(0, yoffset, sb->width, font->height); 526 struct drm_panic_line line_wrap; 527 528 if (line->len > chars_per_row) { 529 line_wrap.len = line->len % chars_per_row; 530 line_wrap.txt = line->txt + line->len - line_wrap.len; 531 draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color); 532 r_txt.y1 -= font->height; 533 if (r_txt.y1 < 0) 534 return r_txt.y1; 535 while (line_wrap.txt > line->txt) { 536 line_wrap.txt -= chars_per_row; 537 line_wrap.len = chars_per_row; 538 draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color); 539 r_txt.y1 -= font->height; 540 if (r_txt.y1 < 0) 541 return r_txt.y1; 542 } 543 } else { 544 draw_txt_rectangle(sb, font, line, 1, false, &r_txt, fg_color); 545 r_txt.y1 -= font->height; 546 } 547 return r_txt.y1; 548 } 549 550 /* 551 * Draw the kmsg buffer to the screen, starting from the youngest message at the bottom, 552 * and going up until reaching the top of the screen. 553 */ 554 static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb) 555 { 556 u32 fg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, 557 sb->format->format); 558 u32 bg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, 559 sb->format->format); 560 const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL); 561 struct drm_rect r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height); 562 struct kmsg_dump_iter iter; 563 char kmsg_buf[512]; 564 size_t kmsg_len; 565 struct drm_panic_line line; 566 int yoffset; 567 568 if (!font || font->width > sb->width) 569 return; 570 571 yoffset = sb->height - font->height - (sb->height % font->height) / 2; 572 573 /* Fill with the background color, and draw text on top */ 574 drm_panic_fill(sb, &r_screen, bg_color); 575 576 kmsg_dump_rewind(&iter); 577 while (kmsg_dump_get_buffer(&iter, false, kmsg_buf, sizeof(kmsg_buf), &kmsg_len)) { 578 char *start; 579 char *end; 580 581 /* ignore terminating NUL and newline */ 582 start = kmsg_buf + kmsg_len - 2; 583 end = kmsg_buf + kmsg_len - 1; 584 while (start > kmsg_buf && yoffset >= 0) { 585 while (start > kmsg_buf && *start != '\n') 586 start--; 587 /* don't count the newline character */ 588 line.txt = start + (start == kmsg_buf ? 0 : 1); 589 line.len = end - line.txt; 590 591 yoffset = draw_line_with_wrap(sb, font, &line, yoffset, fg_color); 592 end = start; 593 start--; 594 } 595 } 596 } 597 598 #if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE) 599 /* 600 * It is unwise to allocate memory in the panic callback, so the buffers are 601 * pre-allocated. Only 2 buffers and the zlib workspace are needed. 602 * Two buffers are enough, using the following buffer usage: 603 * 1) kmsg messages are dumped in buffer1 604 * 2) kmsg is zlib-compressed into buffer2 605 * 3) compressed kmsg is encoded as QR-code Numeric stream in buffer1 606 * 4) QR-code image is generated in buffer2 607 * The Max QR code size is V40, 177x177, 4071 bytes for image, 2956 bytes for 608 * data segments. 609 * 610 * Typically, ~7500 bytes of kmsg, are compressed into 2800 bytes, which fits in 611 * a V40 QR-code (177x177). 612 * 613 * If CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL is not set, the kmsg data will be put 614 * directly in the QR code. 615 * 1) kmsg messages are dumped in buffer1 616 * 2) kmsg message is encoded as byte stream in buffer2 617 * 3) QR-code image is generated in buffer1 618 */ 619 620 static uint panic_qr_version = CONFIG_DRM_PANIC_SCREEN_QR_VERSION; 621 module_param(panic_qr_version, uint, 0644); 622 MODULE_PARM_DESC(panic_qr_version, "maximum version (size) of the QR code"); 623 624 #define MAX_QR_DATA 2956 625 #define MAX_ZLIB_RATIO 3 626 #define QR_BUFFER1_SIZE (MAX_ZLIB_RATIO * MAX_QR_DATA) /* Must also be > 4071 */ 627 #define QR_BUFFER2_SIZE 4096 628 #define QR_MARGIN 4 /* 4 modules of foreground color around the qr code */ 629 630 /* Compression parameters */ 631 #define COMPR_LEVEL 6 632 #define WINDOW_BITS 12 633 #define MEM_LEVEL 4 634 635 static char *qrbuf1; 636 static char *qrbuf2; 637 static struct z_stream_s stream; 638 639 static void __init drm_panic_qr_init(void) 640 { 641 qrbuf1 = kmalloc(QR_BUFFER1_SIZE, GFP_KERNEL); 642 qrbuf2 = kmalloc(QR_BUFFER2_SIZE, GFP_KERNEL); 643 stream.workspace = kmalloc(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL), 644 GFP_KERNEL); 645 } 646 647 static void drm_panic_qr_exit(void) 648 { 649 kfree(qrbuf1); 650 qrbuf1 = NULL; 651 kfree(qrbuf2); 652 qrbuf2 = NULL; 653 kfree(stream.workspace); 654 stream.workspace = NULL; 655 } 656 657 static int drm_panic_get_qr_code_url(u8 **qr_image) 658 { 659 struct kmsg_dump_iter iter; 660 char url[256]; 661 size_t kmsg_len, max_kmsg_size; 662 char *kmsg; 663 int max_qr_data_size, url_len; 664 665 url_len = snprintf(url, sizeof(url), CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL "?a=%s&v=%s&z=", 666 utsname()->machine, utsname()->release); 667 668 max_qr_data_size = drm_panic_qr_max_data_size(panic_qr_version, url_len); 669 max_kmsg_size = min(MAX_ZLIB_RATIO * max_qr_data_size, QR_BUFFER1_SIZE); 670 671 /* get kmsg to buffer 1 */ 672 kmsg_dump_rewind(&iter); 673 kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len); 674 675 if (!kmsg_len) 676 return -ENODATA; 677 kmsg = qrbuf1; 678 679 try_again: 680 if (zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS, 681 MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK) 682 return -EINVAL; 683 684 stream.next_in = kmsg; 685 stream.avail_in = kmsg_len; 686 stream.total_in = 0; 687 stream.next_out = qrbuf2; 688 stream.avail_out = QR_BUFFER2_SIZE; 689 stream.total_out = 0; 690 691 if (zlib_deflate(&stream, Z_FINISH) != Z_STREAM_END) 692 return -EINVAL; 693 694 if (zlib_deflateEnd(&stream) != Z_OK) 695 return -EINVAL; 696 697 if (stream.total_out > max_qr_data_size) { 698 /* too much data for the QR code, so skip the first line and try again */ 699 kmsg = strchr(kmsg, '\n'); 700 if (!kmsg) 701 return -EINVAL; 702 /* skip the first \n */ 703 kmsg += 1; 704 kmsg_len = strlen(kmsg); 705 goto try_again; 706 } 707 *qr_image = qrbuf2; 708 709 /* generate qr code image in buffer2 */ 710 return drm_panic_qr_generate(url, qrbuf2, stream.total_out, QR_BUFFER2_SIZE, 711 qrbuf1, QR_BUFFER1_SIZE); 712 } 713 714 static int drm_panic_get_qr_code_raw(u8 **qr_image) 715 { 716 struct kmsg_dump_iter iter; 717 size_t kmsg_len; 718 size_t max_kmsg_size = min(drm_panic_qr_max_data_size(panic_qr_version, 0), 719 QR_BUFFER1_SIZE); 720 721 kmsg_dump_rewind(&iter); 722 kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len); 723 if (!kmsg_len) 724 return -ENODATA; 725 726 *qr_image = qrbuf1; 727 return drm_panic_qr_generate(NULL, qrbuf1, kmsg_len, QR_BUFFER1_SIZE, 728 qrbuf2, QR_BUFFER2_SIZE); 729 } 730 731 static int drm_panic_get_qr_code(u8 **qr_image) 732 { 733 if (strlen(CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL) > 0) 734 return drm_panic_get_qr_code_url(qr_image); 735 else 736 return drm_panic_get_qr_code_raw(qr_image); 737 } 738 739 /* 740 * Draw the panic message at the center of the screen, with a QR Code 741 */ 742 static int _draw_panic_static_qr_code(struct drm_scanout_buffer *sb) 743 { 744 u32 fg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, 745 sb->format->format); 746 u32 bg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, 747 sb->format->format); 748 const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL); 749 struct drm_rect r_screen, r_logo, r_msg, r_qr, r_qr_canvas; 750 unsigned int max_qr_size, scale; 751 unsigned int msg_width, msg_height; 752 int qr_width, qr_canvas_width, qr_pitch, v_margin; 753 u8 *qr_image; 754 755 if (!font || !qrbuf1 || !qrbuf2 || !stream.workspace) 756 return -ENOMEM; 757 758 r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height); 759 760 drm_panic_logo_rect(&r_logo, font); 761 762 msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width); 763 msg_height = min(panic_msg_lines * font->height, sb->height); 764 r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height); 765 766 max_qr_size = min(3 * sb->width / 4, 3 * sb->height / 4); 767 768 qr_width = drm_panic_get_qr_code(&qr_image); 769 if (qr_width <= 0) 770 return -ENOSPC; 771 772 qr_canvas_width = qr_width + QR_MARGIN * 2; 773 scale = max_qr_size / qr_canvas_width; 774 /* QR code is not readable if not scaled at least by 2 */ 775 if (scale < 2) 776 return -ENOSPC; 777 778 pr_debug("QR width %d and scale %d\n", qr_width, scale); 779 r_qr_canvas = DRM_RECT_INIT(0, 0, qr_canvas_width * scale, qr_canvas_width * scale); 780 781 v_margin = sb->height - drm_rect_height(&r_qr_canvas) - drm_rect_height(&r_msg); 782 if (v_margin < 0) 783 return -ENOSPC; 784 v_margin /= 5; 785 786 drm_rect_translate(&r_qr_canvas, (sb->width - r_qr_canvas.x2) / 2, 2 * v_margin); 787 r_qr = DRM_RECT_INIT(r_qr_canvas.x1 + QR_MARGIN * scale, r_qr_canvas.y1 + QR_MARGIN * scale, 788 qr_width * scale, qr_width * scale); 789 790 /* Center the panic message */ 791 drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, 792 3 * v_margin + drm_rect_height(&r_qr_canvas)); 793 794 /* Fill with the background color, and draw text on top */ 795 drm_panic_fill(sb, &r_screen, bg_color); 796 797 if (!drm_rect_overlap(&r_logo, &r_msg) && !drm_rect_overlap(&r_logo, &r_qr_canvas)) 798 drm_panic_logo_draw(sb, &r_logo, font, fg_color); 799 800 draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color); 801 802 /* Draw the qr code */ 803 qr_pitch = DIV_ROUND_UP(qr_width, 8); 804 drm_panic_fill(sb, &r_qr_canvas, fg_color); 805 drm_panic_fill(sb, &r_qr, bg_color); 806 drm_panic_blit(sb, &r_qr, qr_image, qr_pitch, scale, fg_color); 807 return 0; 808 } 809 810 static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb) 811 { 812 if (_draw_panic_static_qr_code(sb)) 813 draw_panic_static_user(sb); 814 } 815 #else 816 static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb) 817 { 818 draw_panic_static_user(sb); 819 } 820 821 static void drm_panic_qr_init(void) {}; 822 static void drm_panic_qr_exit(void) {}; 823 #endif 824 825 /* 826 * drm_panic_is_format_supported() 827 * @format: a fourcc color code 828 * Returns: true if supported, false otherwise. 829 * 830 * Check if drm_panic will be able to use this color format. 831 */ 832 static bool drm_panic_is_format_supported(const struct drm_format_info *format) 833 { 834 if (format->num_planes != 1) 835 return false; 836 return drm_draw_color_from_xrgb8888(0xffffff, format->format) != 0; 837 } 838 839 static void draw_panic_dispatch(struct drm_scanout_buffer *sb) 840 { 841 if (!strcmp(drm_panic_screen, "kmsg")) { 842 draw_panic_static_kmsg(sb); 843 } else if (!strcmp(drm_panic_screen, "qr_code")) { 844 draw_panic_static_qr_code(sb); 845 } else { 846 draw_panic_static_user(sb); 847 } 848 } 849 850 static void drm_panic_set_description(const char *description) 851 { 852 u32 len; 853 854 if (description) { 855 struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1]; 856 857 desc_line->txt = description; 858 len = strlen(description); 859 /* ignore the last newline character */ 860 if (len && description[len - 1] == '\n') 861 len -= 1; 862 desc_line->len = len; 863 } 864 } 865 866 static void drm_panic_clear_description(void) 867 { 868 struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1]; 869 870 desc_line->len = 0; 871 desc_line->txt = NULL; 872 } 873 874 static void draw_panic_plane(struct drm_plane *plane, const char *description) 875 { 876 struct drm_scanout_buffer sb = { }; 877 int ret; 878 unsigned long flags; 879 880 if (!drm_panic_trylock(plane->dev, flags)) 881 return; 882 883 ret = plane->helper_private->get_scanout_buffer(plane, &sb); 884 885 if (ret || !drm_panic_is_format_supported(sb.format)) 886 goto unlock; 887 888 /* One of these should be set, or it can't draw pixels */ 889 if (!sb.set_pixel && !sb.pages && iosys_map_is_null(&sb.map[0])) 890 goto unlock; 891 892 drm_panic_set_description(description); 893 894 draw_panic_dispatch(&sb); 895 if (plane->helper_private->panic_flush) 896 plane->helper_private->panic_flush(plane); 897 898 drm_panic_clear_description(); 899 900 unlock: 901 drm_panic_unlock(plane->dev, flags); 902 } 903 904 static struct drm_plane *to_drm_plane(struct kmsg_dumper *kd) 905 { 906 return container_of(kd, struct drm_plane, kmsg_panic); 907 } 908 909 static void drm_panic(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detail) 910 { 911 struct drm_plane *plane = to_drm_plane(dumper); 912 913 if (detail->reason == KMSG_DUMP_PANIC) 914 draw_panic_plane(plane, detail->description); 915 } 916 917 918 /* 919 * DEBUG FS, This is currently unsafe. 920 * Create one file per plane, so it's possible to debug one plane at a time. 921 * TODO: It would be better to emulate an NMI context. 922 */ 923 #ifdef CONFIG_DRM_PANIC_DEBUG 924 #include <linux/debugfs.h> 925 926 static ssize_t debugfs_trigger_write(struct file *file, const char __user *user_buf, 927 size_t count, loff_t *ppos) 928 { 929 bool run; 930 931 if (kstrtobool_from_user(user_buf, count, &run) == 0 && run) { 932 struct drm_plane *plane = file->private_data; 933 934 draw_panic_plane(plane, "Test from debugfs"); 935 } 936 return count; 937 } 938 939 static const struct file_operations dbg_drm_panic_ops = { 940 .owner = THIS_MODULE, 941 .write = debugfs_trigger_write, 942 .open = simple_open, 943 }; 944 945 static void debugfs_register_plane(struct drm_plane *plane, int index) 946 { 947 char fname[32]; 948 949 snprintf(fname, 32, "drm_panic_plane_%d", index); 950 debugfs_create_file(fname, 0200, plane->dev->debugfs_root, 951 plane, &dbg_drm_panic_ops); 952 } 953 #else 954 static void debugfs_register_plane(struct drm_plane *plane, int index) {} 955 #endif /* CONFIG_DRM_PANIC_DEBUG */ 956 957 /** 958 * drm_panic_is_enabled 959 * @dev: the drm device that may supports drm_panic 960 * 961 * returns true if the drm device supports drm_panic 962 */ 963 bool drm_panic_is_enabled(struct drm_device *dev) 964 { 965 struct drm_plane *plane; 966 967 if (!dev->mode_config.num_total_plane) 968 return false; 969 970 drm_for_each_plane(plane, dev) 971 if (plane->helper_private && plane->helper_private->get_scanout_buffer) 972 return true; 973 return false; 974 } 975 EXPORT_SYMBOL(drm_panic_is_enabled); 976 977 /** 978 * drm_panic_register() - Initialize DRM panic for a device 979 * @dev: the drm device on which the panic screen will be displayed. 980 */ 981 void drm_panic_register(struct drm_device *dev) 982 { 983 struct drm_plane *plane; 984 int registered_plane = 0; 985 986 if (!dev->mode_config.num_total_plane) 987 return; 988 989 drm_for_each_plane(plane, dev) { 990 if (!plane->helper_private || !plane->helper_private->get_scanout_buffer) 991 continue; 992 plane->kmsg_panic.dump = drm_panic; 993 plane->kmsg_panic.max_reason = KMSG_DUMP_PANIC; 994 if (kmsg_dump_register(&plane->kmsg_panic)) 995 drm_warn(dev, "Failed to register panic handler\n"); 996 else { 997 debugfs_register_plane(plane, registered_plane); 998 registered_plane++; 999 } 1000 } 1001 if (registered_plane) 1002 drm_info(dev, "Registered %d planes with drm panic\n", registered_plane); 1003 } 1004 1005 /** 1006 * drm_panic_unregister() 1007 * @dev: the drm device previously registered. 1008 */ 1009 void drm_panic_unregister(struct drm_device *dev) 1010 { 1011 struct drm_plane *plane; 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 kmsg_dump_unregister(&plane->kmsg_panic); 1020 } 1021 } 1022 1023 /** 1024 * drm_panic_init() - initialize DRM panic. 1025 */ 1026 void __init drm_panic_init(void) 1027 { 1028 drm_panic_qr_init(); 1029 } 1030 1031 /** 1032 * drm_panic_exit() - Free the resources taken by drm_panic_exit() 1033 */ 1034 void drm_panic_exit(void) 1035 { 1036 drm_panic_qr_exit(); 1037 } 1038