1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Framebuffer driver for EFI/UEFI based system
4 *
5 * (c) 2006 Edgar Hucek <gimli@dark-green.com>
6 * Original efi driver written by Gerd Knorr <kraxel@goldbach.in-berlin.de>
7 *
8 */
9
10#include <linux/aperture.h>
11#include <linux/kernel.h>
12#include <linux/efi.h>
13#include <linux/efi-bgrt.h>
14#include <linux/errno.h>
15#include <linux/fb.h>
16#include <linux/platform_device.h>
17#include <linux/printk.h>
18#include <linux/screen_info.h>
19#include <video/vga.h>
20#include <asm/efi.h>
21#include <drm/drm_utils.h> /* For drm_get_panel_orientation_quirk */
22#include <drm/drm_connector.h> /* For DRM_MODE_PANEL_ORIENTATION_* */
23
24struct bmp_file_header {
25 u16 id;
26 u32 file_size;
27 u32 reserved;
28 u32 bitmap_offset;
29} __packed;
30
31struct bmp_dib_header {
32 u32 dib_header_size;
33 s32 width;
34 s32 height;
35 u16 planes;
36 u16 bpp;
37 u32 compression;
38 u32 bitmap_size;
39 u32 horz_resolution;
40 u32 vert_resolution;
41 u32 colors_used;
42 u32 colors_important;
43} __packed;
44
45static bool use_bgrt = true;
46static bool request_mem_succeeded = false;
47static u64 mem_flags = EFI_MEMORY_WC | EFI_MEMORY_UC;
48
49struct efifb_par {
50 u32 pseudo_palette[16];
51 resource_size_t base;
52 resource_size_t size;
53};
54
55static struct fb_var_screeninfo efifb_defined = {
56 .activate = FB_ACTIVATE_NOW,
57 .height = -1,
58 .width = -1,
59 .right_margin = 32,
60 .upper_margin = 16,
61 .lower_margin = 4,
62 .vsync_len = 4,
63 .vmode = FB_VMODE_NONINTERLACED,
64};
65
66static struct fb_fix_screeninfo efifb_fix = {
67 .id = "EFI VGA",
68 .type = FB_TYPE_PACKED_PIXELS,
69 .accel = FB_ACCEL_NONE,
70 .visual = FB_VISUAL_TRUECOLOR,
71};
72
73static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
74 unsigned blue, unsigned transp,
75 struct fb_info *info)
76{
77 /*
78 * Set a single color register. The values supplied are
79 * already rounded down to the hardware's capabilities
80 * (according to the entries in the `var' structure). Return
81 * != 0 for invalid regno.
82 */
83
84 if (regno >= info->cmap.len)
85 return 1;
86
87 if (regno < 16) {
88 red >>= 16 - info->var.red.length;
89 green >>= 16 - info->var.green.length;
90 blue >>= 16 - info->var.blue.length;
91 ((u32 *)(info->pseudo_palette))[regno] =
92 (red << info->var.red.offset) |
93 (green << info->var.green.offset) |
94 (blue << info->var.blue.offset);
95 }
96 return 0;
97}
98
99/*
100 * If fbcon deffered console takeover is configured, the intent is for the
101 * framebuffer to show the boot graphics (e.g. vendor logo) until there is some
102 * (error) message to display. But the boot graphics may have been destroyed by
103 * e.g. option ROM output, detect this and restore the boot graphics.
104 */
105#if defined CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER && \
106 defined CONFIG_ACPI_BGRT
107static void efifb_copy_bmp(u8 *src, u32 *dst, int width, const struct screen_info *si)
108{
109 u8 r, g, b;
110
111 while (width--) {
112 b = *src++;
113 g = *src++;
114 r = *src++;
115 *dst++ = (r << si->red_pos) |
116 (g << si->green_pos) |
117 (b << si->blue_pos);
118 }
119}
120
121#ifdef CONFIG_X86
122/*
123 * On x86 some firmwares use a low non native resolution for the display when
124 * they have shown some text messages. While keeping the bgrt filled with info
125 * for the native resolution. If the bgrt image intended for the native
126 * resolution still fits, it will be displayed very close to the right edge of
127 * the display looking quite bad. This function checks for this.
128 */
129static bool efifb_bgrt_sanity_check(const struct screen_info *si, u32 bmp_width)
130{
131 /*
132 * All x86 firmwares horizontally center the image (the yoffset
133 * calculations differ between boards, but xoffset is predictable).
134 */
135 u32 expected_xoffset = (si->lfb_width - bmp_width) / 2;
136
137 return bgrt_tab.image_offset_x == expected_xoffset;
138}
139#else
140static bool efifb_bgrt_sanity_check(const struct screen_info *si, u32 bmp_width)
141{
142 return true;
143}
144#endif
145
146static void efifb_show_boot_graphics(struct fb_info *info, const struct screen_info *si)
147{
148 u32 bmp_width, bmp_height, bmp_pitch, dst_x, y, src_y;
149 struct bmp_file_header *file_header;
150 struct bmp_dib_header *dib_header;
151 void *bgrt_image = NULL;
152 u8 *dst = info->screen_base;
153
154 if (!use_bgrt)
155 return;
156
157 if (!bgrt_tab.image_address) {
158 pr_info("efifb: No BGRT, not showing boot graphics\n");
159 return;
160 }
161
162 if (bgrt_tab.status & 0x06) {
163 pr_info("efifb: BGRT rotation bits set, not showing boot graphics\n");
164 return;
165 }
166
167 /* Avoid flashing the logo if we're going to print std probe messages */
168 if (console_loglevel > CONSOLE_LOGLEVEL_QUIET)
169 return;
170
171 /* bgrt_tab.status is unreliable, so we don't check it */
172
173 if (si->lfb_depth != 32) {
174 pr_info("efifb: not 32 bits, not showing boot graphics\n");
175 return;
176 }
177
178 bgrt_image = memremap(offset: bgrt_tab.image_address, size: bgrt_image_size,
179 flags: MEMREMAP_WB);
180 if (!bgrt_image) {
181 pr_warn("efifb: Ignoring BGRT: failed to map image memory\n");
182 return;
183 }
184
185 if (bgrt_image_size < (sizeof(*file_header) + sizeof(*dib_header)))
186 goto error;
187
188 file_header = bgrt_image;
189 if (file_header->id != 0x4d42 || file_header->reserved != 0)
190 goto error;
191
192 dib_header = bgrt_image + sizeof(*file_header);
193 if (dib_header->dib_header_size != 40 || dib_header->width < 0 ||
194 dib_header->planes != 1 || dib_header->bpp != 24 ||
195 dib_header->compression != 0)
196 goto error;
197
198 bmp_width = dib_header->width;
199 bmp_height = abs(dib_header->height);
200 bmp_pitch = round_up(3 * bmp_width, 4);
201
202 if ((file_header->bitmap_offset + bmp_pitch * bmp_height) >
203 bgrt_image_size)
204 goto error;
205
206 if ((bgrt_tab.image_offset_x + bmp_width) > si->lfb_width ||
207 (bgrt_tab.image_offset_y + bmp_height) > si->lfb_height)
208 goto error;
209
210 if (!efifb_bgrt_sanity_check(si, bmp_width))
211 goto error;
212
213 pr_info("efifb: showing boot graphics\n");
214
215 for (y = 0; y < si->lfb_height; y++, dst += si->lfb_linelength) {
216 /* Only background? */
217 if (y < bgrt_tab.image_offset_y ||
218 y >= (bgrt_tab.image_offset_y + bmp_height)) {
219 memset(dst, 0, 4 * si->lfb_width);
220 continue;
221 }
222
223 src_y = y - bgrt_tab.image_offset_y;
224 /* Positive header height means upside down row order */
225 if (dib_header->height > 0)
226 src_y = (bmp_height - 1) - src_y;
227
228 memset(dst, 0, bgrt_tab.image_offset_x * 4);
229 dst_x = bgrt_tab.image_offset_x;
230 efifb_copy_bmp(src: bgrt_image + file_header->bitmap_offset +
231 src_y * bmp_pitch,
232 dst: (u32 *)dst + dst_x, width: bmp_width, si);
233 dst_x += bmp_width;
234 memset((u32 *)dst + dst_x, 0, (si->lfb_width - dst_x) * 4);
235 }
236
237 memunmap(addr: bgrt_image);
238 return;
239
240error:
241 memunmap(addr: bgrt_image);
242 pr_warn("efifb: Ignoring BGRT: unexpected or invalid BMP data\n");
243}
244#else
245static inline void efifb_show_boot_graphics(struct fb_info *info, const struct screen_info *si)
246{ }
247#endif
248
249/*
250 * fb_ops.fb_destroy is called by the last put_fb_info() call at the end
251 * of unregister_framebuffer() or fb_release(). Do any cleanup here.
252 */
253static void efifb_destroy(struct fb_info *info)
254{
255 struct efifb_par *par = info->par;
256
257 if (info->screen_base) {
258 if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
259 iounmap(addr: info->screen_base);
260 else
261 memunmap(addr: info->screen_base);
262 }
263
264 if (request_mem_succeeded)
265 release_mem_region(par->base, par->size);
266 fb_dealloc_cmap(cmap: &info->cmap);
267
268 framebuffer_release(info);
269}
270
271static const struct fb_ops efifb_ops = {
272 .owner = THIS_MODULE,
273 FB_DEFAULT_IOMEM_OPS,
274 .fb_destroy = efifb_destroy,
275 .fb_setcolreg = efifb_setcolreg,
276};
277
278static int efifb_setup(struct screen_info *si, char *options)
279{
280 char *this_opt;
281
282 if (options && *options) {
283 while ((this_opt = strsep(&options, ",")) != NULL) {
284 if (!*this_opt) continue;
285
286 efifb_setup_from_dmi(si, opt: this_opt);
287
288 if (!strncmp(this_opt, "base:", 5))
289 si->lfb_base = simple_strtoul(this_opt+5, NULL, 0);
290 else if (!strncmp(this_opt, "stride:", 7))
291 si->lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
292 else if (!strncmp(this_opt, "height:", 7))
293 si->lfb_height = simple_strtoul(this_opt+7, NULL, 0);
294 else if (!strncmp(this_opt, "width:", 6))
295 si->lfb_width = simple_strtoul(this_opt+6, NULL, 0);
296 else if (!strcmp(this_opt, "nowc"))
297 mem_flags &= ~EFI_MEMORY_WC;
298 else if (!strcmp(this_opt, "nobgrt"))
299 use_bgrt = false;
300 }
301 }
302
303 return 0;
304}
305
306static inline bool fb_base_is_valid(struct screen_info *si)
307{
308 if (si->lfb_base)
309 return true;
310
311 if (!(si->capabilities & VIDEO_CAPABILITY_64BIT_BASE))
312 return false;
313
314 if (si->ext_lfb_base)
315 return true;
316
317 return false;
318}
319
320#define efifb_attr_decl(name, fmt) \
321static ssize_t name##_show(struct device *dev, \
322 struct device_attribute *attr, \
323 char *buf) \
324{ \
325 struct screen_info *si = dev_get_platdata(dev); \
326 if (!si) \
327 return -ENODEV; \
328 return sprintf(buf, fmt "\n", (si->lfb_##name)); \
329} \
330static DEVICE_ATTR_RO(name)
331
332efifb_attr_decl(base, "0x%x");
333efifb_attr_decl(linelength, "%u");
334efifb_attr_decl(height, "%u");
335efifb_attr_decl(width, "%u");
336efifb_attr_decl(depth, "%u");
337
338static struct attribute *efifb_attrs[] = {
339 &dev_attr_base.attr,
340 &dev_attr_linelength.attr,
341 &dev_attr_width.attr,
342 &dev_attr_height.attr,
343 &dev_attr_depth.attr,
344 NULL
345};
346ATTRIBUTE_GROUPS(efifb);
347
348static int efifb_probe(struct platform_device *dev)
349{
350 struct screen_info *si;
351 struct fb_info *info;
352 struct efifb_par *par;
353 int err, orientation;
354 unsigned int size_vmode;
355 unsigned int size_remap;
356 unsigned int size_total;
357 char *option = NULL;
358 efi_memory_desc_t md;
359
360 /*
361 * If we fail probing the device, the kernel might try a different
362 * driver. We get a copy of the attached screen_info, so that we can
363 * modify its values without affecting later drivers.
364 */
365 si = dev_get_platdata(dev: &dev->dev);
366 if (!si)
367 return -ENODEV;
368 si = devm_kmemdup(dev: &dev->dev, src: si, len: sizeof(*si), GFP_KERNEL);
369 if (!si)
370 return -ENOMEM;
371
372 if (si->orig_video_isVGA != VIDEO_TYPE_EFI)
373 return -ENODEV;
374
375 if (fb_get_options(name: "efifb", option: &option))
376 return -ENODEV;
377 efifb_setup(si, options: option);
378
379 /* We don't get linelength from UGA Draw Protocol, only from
380 * EFI Graphics Protocol. So if it's not in DMI, and it's not
381 * passed in from the user, we really can't use the framebuffer.
382 */
383 if (!si->lfb_linelength)
384 return -ENODEV;
385
386 if (!si->lfb_depth)
387 si->lfb_depth = 32;
388 if (!si->pages)
389 si->pages = 1;
390 if (!fb_base_is_valid(si)) {
391 printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
392 return -ENODEV;
393 }
394 printk(KERN_INFO "efifb: probing for efifb\n");
395
396 /* just assume they're all unset if any are */
397 if (!si->blue_size) {
398 si->blue_size = 8;
399 si->blue_pos = 0;
400 si->green_size = 8;
401 si->green_pos = 8;
402 si->red_size = 8;
403 si->red_pos = 16;
404 si->rsvd_size = 8;
405 si->rsvd_pos = 24;
406 }
407
408 efifb_fix.smem_start = __screen_info_lfb_base(si);
409
410 efifb_defined.bits_per_pixel = si->lfb_depth;
411 efifb_defined.xres = si->lfb_width;
412 efifb_defined.yres = si->lfb_height;
413 efifb_fix.line_length = si->lfb_linelength;
414
415 /* size_vmode -- that is the amount of memory needed for the
416 * used video mode, i.e. the minimum amount of
417 * memory we need. */
418 size_vmode = efifb_defined.yres * efifb_fix.line_length;
419
420 /* size_total -- all video memory we have. Used for
421 * entries, ressource allocation and bounds
422 * checking. */
423 size_total = si->lfb_size;
424 if (size_total < size_vmode)
425 size_total = size_vmode;
426
427 /* size_remap -- the amount of video memory we are going to
428 * use for efifb. With modern cards it is no
429 * option to simply use size_total as that
430 * wastes plenty of kernel address space. */
431 size_remap = size_vmode * 2;
432 if (size_remap > size_total)
433 size_remap = size_total;
434 if (size_remap % PAGE_SIZE)
435 size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
436 efifb_fix.smem_len = size_remap;
437
438 if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
439 request_mem_succeeded = true;
440 } else {
441 /* We cannot make this fatal. Sometimes this comes from magic
442 spaces our resource handlers simply don't know about */
443 pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
444 efifb_fix.smem_start);
445 }
446
447 info = framebuffer_alloc(size: sizeof(*par), dev: &dev->dev);
448 if (!info) {
449 err = -ENOMEM;
450 goto err_release_mem;
451 }
452 platform_set_drvdata(pdev: dev, data: info);
453 par = info->par;
454 info->pseudo_palette = par->pseudo_palette;
455
456 par->base = efifb_fix.smem_start;
457 par->size = size_remap;
458
459 if (efi_enabled(EFI_MEMMAP) &&
460 !efi_mem_desc_lookup(phys_addr: efifb_fix.smem_start, out_md: &md)) {
461 if ((efifb_fix.smem_start + efifb_fix.smem_len) >
462 (md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT))) {
463 pr_err("efifb: video memory @ 0x%lx spans multiple EFI memory regions\n",
464 efifb_fix.smem_start);
465 err = -EIO;
466 goto err_release_fb;
467 }
468 /*
469 * If the UEFI memory map covers the efifb region, we may only
470 * remap it using the attributes the memory map prescribes.
471 */
472 md.attribute &= EFI_MEMORY_UC | EFI_MEMORY_WC |
473 EFI_MEMORY_WT | EFI_MEMORY_WB;
474 if (md.attribute) {
475 mem_flags |= EFI_MEMORY_WT | EFI_MEMORY_WB;
476 mem_flags &= md.attribute;
477 }
478 }
479 if (mem_flags & EFI_MEMORY_WC)
480 info->screen_base = ioremap_wc(offset: efifb_fix.smem_start,
481 size: efifb_fix.smem_len);
482 else if (mem_flags & EFI_MEMORY_UC)
483 info->screen_base = ioremap(offset: efifb_fix.smem_start,
484 size: efifb_fix.smem_len);
485 else if (mem_flags & EFI_MEMORY_WT)
486 info->screen_base = memremap(offset: efifb_fix.smem_start,
487 size: efifb_fix.smem_len, flags: MEMREMAP_WT);
488 else if (mem_flags & EFI_MEMORY_WB)
489 info->screen_base = memremap(offset: efifb_fix.smem_start,
490 size: efifb_fix.smem_len, flags: MEMREMAP_WB);
491 if (!info->screen_base) {
492 pr_err("efifb: abort, cannot remap video memory 0x%x @ 0x%lx\n",
493 efifb_fix.smem_len, efifb_fix.smem_start);
494 err = -EIO;
495 goto err_release_fb;
496 }
497
498 efifb_show_boot_graphics(info, si);
499
500 pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
501 efifb_fix.smem_start, size_remap/1024, size_total/1024);
502 pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
503 efifb_defined.xres, efifb_defined.yres,
504 efifb_defined.bits_per_pixel, efifb_fix.line_length,
505 si->pages);
506
507 efifb_defined.xres_virtual = efifb_defined.xres;
508 efifb_defined.yres_virtual = efifb_fix.smem_len /
509 efifb_fix.line_length;
510 pr_info("efifb: scrolling: redraw\n");
511 efifb_defined.yres_virtual = efifb_defined.yres;
512
513 /* some dummy values for timing to make fbset happy */
514 efifb_defined.pixclock = 10000000 / efifb_defined.xres *
515 1000 / efifb_defined.yres;
516 efifb_defined.left_margin = (efifb_defined.xres / 8) & 0xf8;
517 efifb_defined.hsync_len = (efifb_defined.xres / 8) & 0xf8;
518
519 efifb_defined.red.offset = si->red_pos;
520 efifb_defined.red.length = si->red_size;
521 efifb_defined.green.offset = si->green_pos;
522 efifb_defined.green.length = si->green_size;
523 efifb_defined.blue.offset = si->blue_pos;
524 efifb_defined.blue.length = si->blue_size;
525 efifb_defined.transp.offset = si->rsvd_pos;
526 efifb_defined.transp.length = si->rsvd_size;
527
528 pr_info("efifb: %s: "
529 "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
530 "Truecolor",
531 si->rsvd_size,
532 si->red_size,
533 si->green_size,
534 si->blue_size,
535 si->rsvd_pos,
536 si->red_pos,
537 si->green_pos,
538 si->blue_pos);
539
540 efifb_fix.ypanstep = 0;
541 efifb_fix.ywrapstep = 0;
542
543 info->fbops = &efifb_ops;
544 info->var = efifb_defined;
545 info->fix = efifb_fix;
546
547 orientation = drm_get_panel_orientation_quirk(width: efifb_defined.xres,
548 height: efifb_defined.yres);
549 switch (orientation) {
550 default:
551 info->fbcon_rotate_hint = FB_ROTATE_UR;
552 break;
553 case DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP:
554 info->fbcon_rotate_hint = FB_ROTATE_UD;
555 break;
556 case DRM_MODE_PANEL_ORIENTATION_LEFT_UP:
557 info->fbcon_rotate_hint = FB_ROTATE_CCW;
558 break;
559 case DRM_MODE_PANEL_ORIENTATION_RIGHT_UP:
560 info->fbcon_rotate_hint = FB_ROTATE_CW;
561 break;
562 }
563
564 err = sysfs_create_groups(kobj: &dev->dev.kobj, groups: efifb_groups);
565 if (err) {
566 pr_err("efifb: cannot add sysfs attrs\n");
567 goto err_unmap;
568 }
569 err = fb_alloc_cmap(cmap: &info->cmap, len: 256, transp: 0);
570 if (err < 0) {
571 pr_err("efifb: cannot allocate colormap\n");
572 goto err_groups;
573 }
574
575 err = devm_aperture_acquire_for_platform_device(pdev: dev, base: par->base, size: par->size);
576 if (err) {
577 pr_err("efifb: cannot acquire aperture\n");
578 goto err_fb_dealloc_cmap;
579 }
580 err = register_framebuffer(fb_info: info);
581 if (err < 0) {
582 pr_err("efifb: cannot register framebuffer\n");
583 goto err_fb_dealloc_cmap;
584 }
585 fb_info(info, "%s frame buffer device\n", info->fix.id);
586 return 0;
587
588err_fb_dealloc_cmap:
589 fb_dealloc_cmap(cmap: &info->cmap);
590err_groups:
591 sysfs_remove_groups(kobj: &dev->dev.kobj, groups: efifb_groups);
592err_unmap:
593 if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
594 iounmap(addr: info->screen_base);
595 else
596 memunmap(addr: info->screen_base);
597err_release_fb:
598 framebuffer_release(info);
599err_release_mem:
600 if (request_mem_succeeded)
601 release_mem_region(efifb_fix.smem_start, size_total);
602 return err;
603}
604
605static void efifb_remove(struct platform_device *pdev)
606{
607 struct fb_info *info = platform_get_drvdata(pdev);
608
609 /* efifb_destroy takes care of info cleanup */
610 unregister_framebuffer(fb_info: info);
611 sysfs_remove_groups(kobj: &pdev->dev.kobj, groups: efifb_groups);
612}
613
614static struct platform_driver efifb_driver = {
615 .driver = {
616 .name = "efi-framebuffer",
617 },
618 .probe = efifb_probe,
619 .remove_new = efifb_remove,
620};
621
622builtin_platform_driver(efifb_driver);
623

source code of linux/drivers/video/fbdev/efifb.c