xref: /openbmc/linux/drivers/video/fbdev/efifb.c (revision b593bce5)
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/kernel.h>
11 #include <linux/efi.h>
12 #include <linux/efi-bgrt.h>
13 #include <linux/errno.h>
14 #include <linux/fb.h>
15 #include <linux/pci.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 static struct fb_var_screeninfo efifb_defined = {
50 	.activate		= FB_ACTIVATE_NOW,
51 	.height			= -1,
52 	.width			= -1,
53 	.right_margin		= 32,
54 	.upper_margin		= 16,
55 	.lower_margin		= 4,
56 	.vsync_len		= 4,
57 	.vmode			= FB_VMODE_NONINTERLACED,
58 };
59 
60 static struct fb_fix_screeninfo efifb_fix = {
61 	.id			= "EFI VGA",
62 	.type			= FB_TYPE_PACKED_PIXELS,
63 	.accel			= FB_ACCEL_NONE,
64 	.visual			= FB_VISUAL_TRUECOLOR,
65 };
66 
67 static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
68 			   unsigned blue, unsigned transp,
69 			   struct fb_info *info)
70 {
71 	/*
72 	 *  Set a single color register. The values supplied are
73 	 *  already rounded down to the hardware's capabilities
74 	 *  (according to the entries in the `var' structure). Return
75 	 *  != 0 for invalid regno.
76 	 */
77 
78 	if (regno >= info->cmap.len)
79 		return 1;
80 
81 	if (regno < 16) {
82 		red   >>= 16 - info->var.red.length;
83 		green >>= 16 - info->var.green.length;
84 		blue  >>= 16 - info->var.blue.length;
85 		((u32 *)(info->pseudo_palette))[regno] =
86 			(red   << info->var.red.offset)   |
87 			(green << info->var.green.offset) |
88 			(blue  << info->var.blue.offset);
89 	}
90 	return 0;
91 }
92 
93 /*
94  * If fbcon deffered console takeover is configured, the intent is for the
95  * framebuffer to show the boot graphics (e.g. vendor logo) until there is some
96  * (error) message to display. But the boot graphics may have been destroyed by
97  * e.g. option ROM output, detect this and restore the boot graphics.
98  */
99 #if defined CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER && \
100     defined CONFIG_ACPI_BGRT
101 static void efifb_copy_bmp(u8 *src, u32 *dst, int width, struct screen_info *si)
102 {
103 	u8 r, g, b;
104 
105 	while (width--) {
106 		b = *src++;
107 		g = *src++;
108 		r = *src++;
109 		*dst++ = (r << si->red_pos)   |
110 			 (g << si->green_pos) |
111 			 (b << si->blue_pos);
112 	}
113 }
114 
115 #ifdef CONFIG_X86
116 /*
117  * On x86 some firmwares use a low non native resolution for the display when
118  * they have shown some text messages. While keeping the bgrt filled with info
119  * for the native resolution. If the bgrt image intended for the native
120  * resolution still fits, it will be displayed very close to the right edge of
121  * the display looking quite bad. This function checks for this.
122  */
123 static bool efifb_bgrt_sanity_check(struct screen_info *si, u32 bmp_width)
124 {
125 	static const int default_resolutions[][2] = {
126 		{  800,  600 },
127 		{ 1024,  768 },
128 		{ 1280, 1024 },
129 	};
130 	u32 i, right_margin;
131 
132 	for (i = 0; i < ARRAY_SIZE(default_resolutions); i++) {
133 		if (default_resolutions[i][0] == si->lfb_width &&
134 		    default_resolutions[i][1] == si->lfb_height)
135 			break;
136 	}
137 	/* If not a default resolution used for textmode, this should be fine */
138 	if (i >= ARRAY_SIZE(default_resolutions))
139 		return true;
140 
141 	/* If the right margin is 5 times smaller then the left one, reject */
142 	right_margin = si->lfb_width - (bgrt_tab.image_offset_x + bmp_width);
143 	if (right_margin < (bgrt_tab.image_offset_x / 5))
144 		return false;
145 
146 	return true;
147 }
148 #else
149 static bool efifb_bgrt_sanity_check(struct screen_info *si, u32 bmp_width)
150 {
151 	return true;
152 }
153 #endif
154 
155 static void efifb_show_boot_graphics(struct fb_info *info)
156 {
157 	u32 bmp_width, bmp_height, bmp_pitch, screen_pitch, dst_x, y, src_y;
158 	struct screen_info *si = &screen_info;
159 	struct bmp_file_header *file_header;
160 	struct bmp_dib_header *dib_header;
161 	void *bgrt_image = NULL;
162 	u8 *dst = info->screen_base;
163 
164 	if (!use_bgrt)
165 		return;
166 
167 	if (!bgrt_tab.image_address) {
168 		pr_info("efifb: No BGRT, not showing boot graphics\n");
169 		return;
170 	}
171 
172 	if (bgrt_tab.status & 0x06) {
173 		pr_info("efifb: BGRT rotation bits set, not showing boot graphics\n");
174 		return;
175 	}
176 
177 	/* Avoid flashing the logo if we're going to print std probe messages */
178 	if (console_loglevel > CONSOLE_LOGLEVEL_QUIET)
179 		return;
180 
181 	/* bgrt_tab.status is unreliable, so we don't check it */
182 
183 	if (si->lfb_depth != 32) {
184 		pr_info("efifb: not 32 bits, not showing boot graphics\n");
185 		return;
186 	}
187 
188 	bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
189 			      MEMREMAP_WB);
190 	if (!bgrt_image) {
191 		pr_warn("efifb: Ignoring BGRT: failed to map image memory\n");
192 		return;
193 	}
194 
195 	if (bgrt_image_size < (sizeof(*file_header) + sizeof(*dib_header)))
196 		goto error;
197 
198 	file_header = bgrt_image;
199 	if (file_header->id != 0x4d42 || file_header->reserved != 0)
200 		goto error;
201 
202 	dib_header = bgrt_image + sizeof(*file_header);
203 	if (dib_header->dib_header_size != 40 || dib_header->width < 0 ||
204 	    dib_header->planes != 1 || dib_header->bpp != 24 ||
205 	    dib_header->compression != 0)
206 		goto error;
207 
208 	bmp_width = dib_header->width;
209 	bmp_height = abs(dib_header->height);
210 	bmp_pitch = round_up(3 * bmp_width, 4);
211 	screen_pitch = si->lfb_linelength;
212 
213 	if ((file_header->bitmap_offset + bmp_pitch * bmp_height) >
214 				bgrt_image_size)
215 		goto error;
216 
217 	if ((bgrt_tab.image_offset_x + bmp_width) > si->lfb_width ||
218 	    (bgrt_tab.image_offset_y + bmp_height) > si->lfb_height)
219 		goto error;
220 
221 	if (!efifb_bgrt_sanity_check(si, bmp_width))
222 		goto error;
223 
224 	pr_info("efifb: showing boot graphics\n");
225 
226 	for (y = 0; y < si->lfb_height; y++, dst += si->lfb_linelength) {
227 		/* Only background? */
228 		if (y < bgrt_tab.image_offset_y ||
229 		    y >= (bgrt_tab.image_offset_y + bmp_height)) {
230 			memset(dst, 0, 4 * si->lfb_width);
231 			continue;
232 		}
233 
234 		src_y = y - bgrt_tab.image_offset_y;
235 		/* Positive header height means upside down row order */
236 		if (dib_header->height > 0)
237 			src_y = (bmp_height - 1) - src_y;
238 
239 		memset(dst, 0, bgrt_tab.image_offset_x * 4);
240 		dst_x = bgrt_tab.image_offset_x;
241 		efifb_copy_bmp(bgrt_image + file_header->bitmap_offset +
242 					    src_y * bmp_pitch,
243 			       (u32 *)dst + dst_x, bmp_width, si);
244 		dst_x += bmp_width;
245 		memset((u32 *)dst + dst_x, 0, (si->lfb_width - dst_x) * 4);
246 	}
247 
248 	memunmap(bgrt_image);
249 	return;
250 
251 error:
252 	memunmap(bgrt_image);
253 	pr_warn("efifb: Ignoring BGRT: unexpected or invalid BMP data\n");
254 }
255 #else
256 static inline void efifb_show_boot_graphics(struct fb_info *info) {}
257 #endif
258 
259 static void efifb_destroy(struct fb_info *info)
260 {
261 	if (info->screen_base) {
262 		if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
263 			iounmap(info->screen_base);
264 		else
265 			memunmap(info->screen_base);
266 	}
267 	if (request_mem_succeeded)
268 		release_mem_region(info->apertures->ranges[0].base,
269 				   info->apertures->ranges[0].size);
270 	fb_dealloc_cmap(&info->cmap);
271 }
272 
273 static struct fb_ops efifb_ops = {
274 	.owner		= THIS_MODULE,
275 	.fb_destroy	= efifb_destroy,
276 	.fb_setcolreg	= efifb_setcolreg,
277 	.fb_fillrect	= cfb_fillrect,
278 	.fb_copyarea	= cfb_copyarea,
279 	.fb_imageblit	= cfb_imageblit,
280 };
281 
282 static int efifb_setup(char *options)
283 {
284 	char *this_opt;
285 
286 	if (options && *options) {
287 		while ((this_opt = strsep(&options, ",")) != NULL) {
288 			if (!*this_opt) continue;
289 
290 			efifb_setup_from_dmi(&screen_info, this_opt);
291 
292 			if (!strncmp(this_opt, "base:", 5))
293 				screen_info.lfb_base = simple_strtoul(this_opt+5, NULL, 0);
294 			else if (!strncmp(this_opt, "stride:", 7))
295 				screen_info.lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
296 			else if (!strncmp(this_opt, "height:", 7))
297 				screen_info.lfb_height = simple_strtoul(this_opt+7, NULL, 0);
298 			else if (!strncmp(this_opt, "width:", 6))
299 				screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);
300 			else if (!strcmp(this_opt, "nowc"))
301 				mem_flags &= ~EFI_MEMORY_WC;
302 			else if (!strcmp(this_opt, "nobgrt"))
303 				use_bgrt = false;
304 		}
305 	}
306 
307 	return 0;
308 }
309 
310 static inline bool fb_base_is_valid(void)
311 {
312 	if (screen_info.lfb_base)
313 		return true;
314 
315 	if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
316 		return false;
317 
318 	if (screen_info.ext_lfb_base)
319 		return true;
320 
321 	return false;
322 }
323 
324 #define efifb_attr_decl(name, fmt)					\
325 static ssize_t name##_show(struct device *dev,				\
326 			   struct device_attribute *attr,		\
327 			   char *buf)					\
328 {									\
329 	return sprintf(buf, fmt "\n", (screen_info.lfb_##name));	\
330 }									\
331 static DEVICE_ATTR_RO(name)
332 
333 efifb_attr_decl(base, "0x%x");
334 efifb_attr_decl(linelength, "%u");
335 efifb_attr_decl(height, "%u");
336 efifb_attr_decl(width, "%u");
337 efifb_attr_decl(depth, "%u");
338 
339 static struct attribute *efifb_attrs[] = {
340 	&dev_attr_base.attr,
341 	&dev_attr_linelength.attr,
342 	&dev_attr_width.attr,
343 	&dev_attr_height.attr,
344 	&dev_attr_depth.attr,
345 	NULL
346 };
347 ATTRIBUTE_GROUPS(efifb);
348 
349 static bool pci_dev_disabled;	/* FB base matches BAR of a disabled device */
350 
351 static struct pci_dev *efifb_pci_dev;	/* dev with BAR covering the efifb */
352 static struct resource *bar_resource;
353 static u64 bar_offset;
354 
355 static int efifb_probe(struct platform_device *dev)
356 {
357 	struct fb_info *info;
358 	int err, orientation;
359 	unsigned int size_vmode;
360 	unsigned int size_remap;
361 	unsigned int size_total;
362 	char *option = NULL;
363 	efi_memory_desc_t md;
364 
365 	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
366 		return -ENODEV;
367 
368 	if (fb_get_options("efifb", &option))
369 		return -ENODEV;
370 	efifb_setup(option);
371 
372 	/* We don't get linelength from UGA Draw Protocol, only from
373 	 * EFI Graphics Protocol.  So if it's not in DMI, and it's not
374 	 * passed in from the user, we really can't use the framebuffer.
375 	 */
376 	if (!screen_info.lfb_linelength)
377 		return -ENODEV;
378 
379 	if (!screen_info.lfb_depth)
380 		screen_info.lfb_depth = 32;
381 	if (!screen_info.pages)
382 		screen_info.pages = 1;
383 	if (!fb_base_is_valid()) {
384 		printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
385 		return -ENODEV;
386 	}
387 	printk(KERN_INFO "efifb: probing for efifb\n");
388 
389 	/* just assume they're all unset if any are */
390 	if (!screen_info.blue_size) {
391 		screen_info.blue_size = 8;
392 		screen_info.blue_pos = 0;
393 		screen_info.green_size = 8;
394 		screen_info.green_pos = 8;
395 		screen_info.red_size = 8;
396 		screen_info.red_pos = 16;
397 		screen_info.rsvd_size = 8;
398 		screen_info.rsvd_pos = 24;
399 	}
400 
401 	efifb_fix.smem_start = screen_info.lfb_base;
402 
403 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
404 		u64 ext_lfb_base;
405 
406 		ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
407 		efifb_fix.smem_start |= ext_lfb_base;
408 	}
409 
410 	if (bar_resource &&
411 	    bar_resource->start + bar_offset != efifb_fix.smem_start) {
412 		dev_info(&efifb_pci_dev->dev,
413 			 "BAR has moved, updating efifb address\n");
414 		efifb_fix.smem_start = bar_resource->start + bar_offset;
415 	}
416 
417 	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
418 	efifb_defined.xres = screen_info.lfb_width;
419 	efifb_defined.yres = screen_info.lfb_height;
420 	efifb_fix.line_length = screen_info.lfb_linelength;
421 
422 	/*   size_vmode -- that is the amount of memory needed for the
423 	 *                 used video mode, i.e. the minimum amount of
424 	 *                 memory we need. */
425 	size_vmode = efifb_defined.yres * efifb_fix.line_length;
426 
427 	/*   size_total -- all video memory we have. Used for
428 	 *                 entries, ressource allocation and bounds
429 	 *                 checking. */
430 	size_total = screen_info.lfb_size;
431 	if (size_total < size_vmode)
432 		size_total = size_vmode;
433 
434 	/*   size_remap -- the amount of video memory we are going to
435 	 *                 use for efifb.  With modern cards it is no
436 	 *                 option to simply use size_total as that
437 	 *                 wastes plenty of kernel address space. */
438 	size_remap  = size_vmode * 2;
439 	if (size_remap > size_total)
440 		size_remap = size_total;
441 	if (size_remap % PAGE_SIZE)
442 		size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
443 	efifb_fix.smem_len = size_remap;
444 
445 	if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
446 		request_mem_succeeded = true;
447 	} else {
448 		/* We cannot make this fatal. Sometimes this comes from magic
449 		   spaces our resource handlers simply don't know about */
450 		pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
451 			efifb_fix.smem_start);
452 	}
453 
454 	info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
455 	if (!info) {
456 		err = -ENOMEM;
457 		goto err_release_mem;
458 	}
459 	platform_set_drvdata(dev, info);
460 	info->pseudo_palette = info->par;
461 	info->par = NULL;
462 
463 	info->apertures = alloc_apertures(1);
464 	if (!info->apertures) {
465 		err = -ENOMEM;
466 		goto err_release_fb;
467 	}
468 	info->apertures->ranges[0].base = efifb_fix.smem_start;
469 	info->apertures->ranges[0].size = size_remap;
470 
471 	if (efi_enabled(EFI_BOOT) &&
472 	    !efi_mem_desc_lookup(efifb_fix.smem_start, &md)) {
473 		if ((efifb_fix.smem_start + efifb_fix.smem_len) >
474 		    (md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT))) {
475 			pr_err("efifb: video memory @ 0x%lx spans multiple EFI memory regions\n",
476 			       efifb_fix.smem_start);
477 			err = -EIO;
478 			goto err_release_fb;
479 		}
480 		/*
481 		 * If the UEFI memory map covers the efifb region, we may only
482 		 * remap it using the attributes the memory map prescribes.
483 		 */
484 		md.attribute &= EFI_MEMORY_UC | EFI_MEMORY_WC |
485 				EFI_MEMORY_WT | EFI_MEMORY_WB;
486 		if (md.attribute) {
487 			mem_flags |= EFI_MEMORY_WT | EFI_MEMORY_WB;
488 			mem_flags &= md.attribute;
489 		}
490 	}
491 	if (mem_flags & EFI_MEMORY_WC)
492 		info->screen_base = ioremap_wc(efifb_fix.smem_start,
493 					       efifb_fix.smem_len);
494 	else if (mem_flags & EFI_MEMORY_UC)
495 		info->screen_base = ioremap(efifb_fix.smem_start,
496 					    efifb_fix.smem_len);
497 	else if (mem_flags & EFI_MEMORY_WT)
498 		info->screen_base = memremap(efifb_fix.smem_start,
499 					     efifb_fix.smem_len, MEMREMAP_WT);
500 	else if (mem_flags & EFI_MEMORY_WB)
501 		info->screen_base = memremap(efifb_fix.smem_start,
502 					     efifb_fix.smem_len, MEMREMAP_WB);
503 	if (!info->screen_base) {
504 		pr_err("efifb: abort, cannot remap video memory 0x%x @ 0x%lx\n",
505 			efifb_fix.smem_len, efifb_fix.smem_start);
506 		err = -EIO;
507 		goto err_release_fb;
508 	}
509 
510 	efifb_show_boot_graphics(info);
511 
512 	pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
513 	       efifb_fix.smem_start, size_remap/1024, size_total/1024);
514 	pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
515 	       efifb_defined.xres, efifb_defined.yres,
516 	       efifb_defined.bits_per_pixel, efifb_fix.line_length,
517 	       screen_info.pages);
518 
519 	efifb_defined.xres_virtual = efifb_defined.xres;
520 	efifb_defined.yres_virtual = efifb_fix.smem_len /
521 					efifb_fix.line_length;
522 	pr_info("efifb: scrolling: redraw\n");
523 	efifb_defined.yres_virtual = efifb_defined.yres;
524 
525 	/* some dummy values for timing to make fbset happy */
526 	efifb_defined.pixclock     = 10000000 / efifb_defined.xres *
527 					1000 / efifb_defined.yres;
528 	efifb_defined.left_margin  = (efifb_defined.xres / 8) & 0xf8;
529 	efifb_defined.hsync_len    = (efifb_defined.xres / 8) & 0xf8;
530 
531 	efifb_defined.red.offset    = screen_info.red_pos;
532 	efifb_defined.red.length    = screen_info.red_size;
533 	efifb_defined.green.offset  = screen_info.green_pos;
534 	efifb_defined.green.length  = screen_info.green_size;
535 	efifb_defined.blue.offset   = screen_info.blue_pos;
536 	efifb_defined.blue.length   = screen_info.blue_size;
537 	efifb_defined.transp.offset = screen_info.rsvd_pos;
538 	efifb_defined.transp.length = screen_info.rsvd_size;
539 
540 	pr_info("efifb: %s: "
541 	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
542 	       "Truecolor",
543 	       screen_info.rsvd_size,
544 	       screen_info.red_size,
545 	       screen_info.green_size,
546 	       screen_info.blue_size,
547 	       screen_info.rsvd_pos,
548 	       screen_info.red_pos,
549 	       screen_info.green_pos,
550 	       screen_info.blue_pos);
551 
552 	efifb_fix.ypanstep  = 0;
553 	efifb_fix.ywrapstep = 0;
554 
555 	info->fbops = &efifb_ops;
556 	info->var = efifb_defined;
557 	info->fix = efifb_fix;
558 	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;
559 
560 	orientation = drm_get_panel_orientation_quirk(efifb_defined.xres,
561 						      efifb_defined.yres);
562 	switch (orientation) {
563 	default:
564 		info->fbcon_rotate_hint = FB_ROTATE_UR;
565 		break;
566 	case DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP:
567 		info->fbcon_rotate_hint = FB_ROTATE_UD;
568 		break;
569 	case DRM_MODE_PANEL_ORIENTATION_LEFT_UP:
570 		info->fbcon_rotate_hint = FB_ROTATE_CCW;
571 		break;
572 	case DRM_MODE_PANEL_ORIENTATION_RIGHT_UP:
573 		info->fbcon_rotate_hint = FB_ROTATE_CW;
574 		break;
575 	}
576 
577 	err = sysfs_create_groups(&dev->dev.kobj, efifb_groups);
578 	if (err) {
579 		pr_err("efifb: cannot add sysfs attrs\n");
580 		goto err_unmap;
581 	}
582 	err = fb_alloc_cmap(&info->cmap, 256, 0);
583 	if (err < 0) {
584 		pr_err("efifb: cannot allocate colormap\n");
585 		goto err_groups;
586 	}
587 	err = register_framebuffer(info);
588 	if (err < 0) {
589 		pr_err("efifb: cannot register framebuffer\n");
590 		goto err_fb_dealoc;
591 	}
592 	fb_info(info, "%s frame buffer device\n", info->fix.id);
593 	return 0;
594 
595 err_fb_dealoc:
596 	fb_dealloc_cmap(&info->cmap);
597 err_groups:
598 	sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
599 err_unmap:
600 	if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
601 		iounmap(info->screen_base);
602 	else
603 		memunmap(info->screen_base);
604 err_release_fb:
605 	framebuffer_release(info);
606 err_release_mem:
607 	if (request_mem_succeeded)
608 		release_mem_region(efifb_fix.smem_start, size_total);
609 	return err;
610 }
611 
612 static int efifb_remove(struct platform_device *pdev)
613 {
614 	struct fb_info *info = platform_get_drvdata(pdev);
615 
616 	unregister_framebuffer(info);
617 	sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
618 	framebuffer_release(info);
619 
620 	return 0;
621 }
622 
623 static struct platform_driver efifb_driver = {
624 	.driver = {
625 		.name = "efi-framebuffer",
626 	},
627 	.probe = efifb_probe,
628 	.remove = efifb_remove,
629 };
630 
631 builtin_platform_driver(efifb_driver);
632 
633 #if defined(CONFIG_PCI)
634 
635 static void record_efifb_bar_resource(struct pci_dev *dev, int idx, u64 offset)
636 {
637 	u16 word;
638 
639 	efifb_pci_dev = dev;
640 
641 	pci_read_config_word(dev, PCI_COMMAND, &word);
642 	if (!(word & PCI_COMMAND_MEMORY)) {
643 		pci_dev_disabled = true;
644 		dev_err(&dev->dev,
645 			"BAR %d: assigned to efifb but device is disabled!\n",
646 			idx);
647 		return;
648 	}
649 
650 	bar_resource = &dev->resource[idx];
651 	bar_offset = offset;
652 
653 	dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
654 }
655 
656 static void efifb_fixup_resources(struct pci_dev *dev)
657 {
658 	u64 base = screen_info.lfb_base;
659 	u64 size = screen_info.lfb_size;
660 	int i;
661 
662 	if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
663 		return;
664 
665 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
666 		base |= (u64)screen_info.ext_lfb_base << 32;
667 
668 	if (!base)
669 		return;
670 
671 	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
672 		struct resource *res = &dev->resource[i];
673 
674 		if (!(res->flags & IORESOURCE_MEM))
675 			continue;
676 
677 		if (res->start <= base && res->end >= base + size - 1) {
678 			record_efifb_bar_resource(dev, i, base - res->start);
679 			break;
680 		}
681 	}
682 }
683 DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY,
684 			       16, efifb_fixup_resources);
685 
686 #endif
687