xref: /linux/drivers/video/fbdev/efifb.c (revision 2a6b6c9a226279b4f6668450ddb21ae655558087)
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 
24 struct bmp_file_header {
25 	u16 id;
26 	u32 file_size;
27 	u32 reserved;
28 	u32 bitmap_offset;
29 } __packed;
30 
31 struct 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 
45 static bool use_bgrt = true;
46 static bool request_mem_succeeded = false;
47 static u64 mem_flags = EFI_MEMORY_WC | EFI_MEMORY_UC;
48 
49 struct efifb_par {
50 	u32 pseudo_palette[16];
51 	resource_size_t base;
52 	resource_size_t size;
53 };
54 
55 static 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 
66 static 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 
73 static 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
107 static 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  */
129 static 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
140 static bool efifb_bgrt_sanity_check(const struct screen_info *si, u32 bmp_width)
141 {
142 	return true;
143 }
144 #endif
145 
146 static 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(bgrt_tab.image_address, bgrt_image_size,
179 			      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(bgrt_image + file_header->bitmap_offset +
231 					    src_y * bmp_pitch,
232 			       (u32 *)dst + dst_x, 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(bgrt_image);
238 	return;
239 
240 error:
241 	memunmap(bgrt_image);
242 	pr_warn("efifb: Ignoring BGRT: unexpected or invalid BMP data\n");
243 }
244 #else
245 static 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  */
253 static 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(info->screen_base);
260 		else
261 			memunmap(info->screen_base);
262 	}
263 
264 	if (request_mem_succeeded)
265 		release_mem_region(par->base, par->size);
266 	fb_dealloc_cmap(&info->cmap);
267 
268 	framebuffer_release(info);
269 }
270 
271 static 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 
278 static 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, 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 
306 static 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)					\
321 static 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 }									\
330 static DEVICE_ATTR_RO(name)
331 
332 efifb_attr_decl(base, "0x%x");
333 efifb_attr_decl(linelength, "%u");
334 efifb_attr_decl(height, "%u");
335 efifb_attr_decl(width, "%u");
336 efifb_attr_decl(depth, "%u");
337 
338 static 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 };
346 ATTRIBUTE_GROUPS(efifb);
347 
348 static 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);
366 	if (!si)
367 		return -ENODEV;
368 	si = devm_kmemdup(&dev->dev, si, 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("efifb", &option))
376 		return -ENODEV;
377 	efifb_setup(si, 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(sizeof(*par), &dev->dev);
448 	if (!info) {
449 		err = -ENOMEM;
450 		goto err_release_mem;
451 	}
452 	platform_set_drvdata(dev, 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(efifb_fix.smem_start, &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(efifb_fix.smem_start,
481 					       efifb_fix.smem_len);
482 	else if (mem_flags & EFI_MEMORY_UC)
483 		info->screen_base = ioremap(efifb_fix.smem_start,
484 					    efifb_fix.smem_len);
485 	else if (mem_flags & EFI_MEMORY_WT)
486 		info->screen_base = memremap(efifb_fix.smem_start,
487 					     efifb_fix.smem_len, MEMREMAP_WT);
488 	else if (mem_flags & EFI_MEMORY_WB)
489 		info->screen_base = memremap(efifb_fix.smem_start,
490 					     efifb_fix.smem_len, 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(efifb_defined.xres,
548 						      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(&dev->dev.kobj, efifb_groups);
565 	if (err) {
566 		pr_err("efifb: cannot add sysfs attrs\n");
567 		goto err_unmap;
568 	}
569 	err = fb_alloc_cmap(&info->cmap, 256, 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(dev, par->base, par->size);
576 	if (err) {
577 		pr_err("efifb: cannot acquire aperture\n");
578 		goto err_fb_dealloc_cmap;
579 	}
580 	err = register_framebuffer(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 
588 err_fb_dealloc_cmap:
589 	fb_dealloc_cmap(&info->cmap);
590 err_groups:
591 	sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
592 err_unmap:
593 	if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
594 		iounmap(info->screen_base);
595 	else
596 		memunmap(info->screen_base);
597 err_release_fb:
598 	framebuffer_release(info);
599 err_release_mem:
600 	if (request_mem_succeeded)
601 		release_mem_region(efifb_fix.smem_start, size_total);
602 	return err;
603 }
604 
605 static 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(info);
611 	sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
612 }
613 
614 static struct platform_driver efifb_driver = {
615 	.driver = {
616 		.name = "efi-framebuffer",
617 	},
618 	.probe = efifb_probe,
619 	.remove_new = efifb_remove,
620 };
621 
622 builtin_platform_driver(efifb_driver);
623