xref: /linux/drivers/video/fbdev/efifb.c (revision 2da68a77)
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 <linux/pm_runtime.h>
20 #include <video/vga.h>
21 #include <asm/efi.h>
22 #include <drm/drm_utils.h> /* For drm_get_panel_orientation_quirk */
23 #include <drm/drm_connector.h>  /* For DRM_MODE_PANEL_ORIENTATION_* */
24 
25 struct bmp_file_header {
26 	u16 id;
27 	u32 file_size;
28 	u32 reserved;
29 	u32 bitmap_offset;
30 } __packed;
31 
32 struct bmp_dib_header {
33 	u32 dib_header_size;
34 	s32 width;
35 	s32 height;
36 	u16 planes;
37 	u16 bpp;
38 	u32 compression;
39 	u32 bitmap_size;
40 	u32 horz_resolution;
41 	u32 vert_resolution;
42 	u32 colors_used;
43 	u32 colors_important;
44 } __packed;
45 
46 static bool use_bgrt = true;
47 static bool request_mem_succeeded = false;
48 static u64 mem_flags = EFI_MEMORY_WC | EFI_MEMORY_UC;
49 
50 static struct pci_dev *efifb_pci_dev;	/* dev with BAR covering the efifb */
51 
52 static struct fb_var_screeninfo efifb_defined = {
53 	.activate		= FB_ACTIVATE_NOW,
54 	.height			= -1,
55 	.width			= -1,
56 	.right_margin		= 32,
57 	.upper_margin		= 16,
58 	.lower_margin		= 4,
59 	.vsync_len		= 4,
60 	.vmode			= FB_VMODE_NONINTERLACED,
61 };
62 
63 static struct fb_fix_screeninfo efifb_fix = {
64 	.id			= "EFI VGA",
65 	.type			= FB_TYPE_PACKED_PIXELS,
66 	.accel			= FB_ACCEL_NONE,
67 	.visual			= FB_VISUAL_TRUECOLOR,
68 };
69 
70 static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
71 			   unsigned blue, unsigned transp,
72 			   struct fb_info *info)
73 {
74 	/*
75 	 *  Set a single color register. The values supplied are
76 	 *  already rounded down to the hardware's capabilities
77 	 *  (according to the entries in the `var' structure). Return
78 	 *  != 0 for invalid regno.
79 	 */
80 
81 	if (regno >= info->cmap.len)
82 		return 1;
83 
84 	if (regno < 16) {
85 		red   >>= 16 - info->var.red.length;
86 		green >>= 16 - info->var.green.length;
87 		blue  >>= 16 - info->var.blue.length;
88 		((u32 *)(info->pseudo_palette))[regno] =
89 			(red   << info->var.red.offset)   |
90 			(green << info->var.green.offset) |
91 			(blue  << info->var.blue.offset);
92 	}
93 	return 0;
94 }
95 
96 /*
97  * If fbcon deffered console takeover is configured, the intent is for the
98  * framebuffer to show the boot graphics (e.g. vendor logo) until there is some
99  * (error) message to display. But the boot graphics may have been destroyed by
100  * e.g. option ROM output, detect this and restore the boot graphics.
101  */
102 #if defined CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER && \
103     defined CONFIG_ACPI_BGRT
104 static void efifb_copy_bmp(u8 *src, u32 *dst, int width, struct screen_info *si)
105 {
106 	u8 r, g, b;
107 
108 	while (width--) {
109 		b = *src++;
110 		g = *src++;
111 		r = *src++;
112 		*dst++ = (r << si->red_pos)   |
113 			 (g << si->green_pos) |
114 			 (b << si->blue_pos);
115 	}
116 }
117 
118 #ifdef CONFIG_X86
119 /*
120  * On x86 some firmwares use a low non native resolution for the display when
121  * they have shown some text messages. While keeping the bgrt filled with info
122  * for the native resolution. If the bgrt image intended for the native
123  * resolution still fits, it will be displayed very close to the right edge of
124  * the display looking quite bad. This function checks for this.
125  */
126 static bool efifb_bgrt_sanity_check(struct screen_info *si, u32 bmp_width)
127 {
128 	/*
129 	 * All x86 firmwares horizontally center the image (the yoffset
130 	 * calculations differ between boards, but xoffset is predictable).
131 	 */
132 	u32 expected_xoffset = (si->lfb_width - bmp_width) / 2;
133 
134 	return bgrt_tab.image_offset_x == expected_xoffset;
135 }
136 #else
137 static bool efifb_bgrt_sanity_check(struct screen_info *si, u32 bmp_width)
138 {
139 	return true;
140 }
141 #endif
142 
143 static void efifb_show_boot_graphics(struct fb_info *info)
144 {
145 	u32 bmp_width, bmp_height, bmp_pitch, dst_x, y, src_y;
146 	struct screen_info *si = &screen_info;
147 	struct bmp_file_header *file_header;
148 	struct bmp_dib_header *dib_header;
149 	void *bgrt_image = NULL;
150 	u8 *dst = info->screen_base;
151 
152 	if (!use_bgrt)
153 		return;
154 
155 	if (!bgrt_tab.image_address) {
156 		pr_info("efifb: No BGRT, not showing boot graphics\n");
157 		return;
158 	}
159 
160 	if (bgrt_tab.status & 0x06) {
161 		pr_info("efifb: BGRT rotation bits set, not showing boot graphics\n");
162 		return;
163 	}
164 
165 	/* Avoid flashing the logo if we're going to print std probe messages */
166 	if (console_loglevel > CONSOLE_LOGLEVEL_QUIET)
167 		return;
168 
169 	/* bgrt_tab.status is unreliable, so we don't check it */
170 
171 	if (si->lfb_depth != 32) {
172 		pr_info("efifb: not 32 bits, not showing boot graphics\n");
173 		return;
174 	}
175 
176 	bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
177 			      MEMREMAP_WB);
178 	if (!bgrt_image) {
179 		pr_warn("efifb: Ignoring BGRT: failed to map image memory\n");
180 		return;
181 	}
182 
183 	if (bgrt_image_size < (sizeof(*file_header) + sizeof(*dib_header)))
184 		goto error;
185 
186 	file_header = bgrt_image;
187 	if (file_header->id != 0x4d42 || file_header->reserved != 0)
188 		goto error;
189 
190 	dib_header = bgrt_image + sizeof(*file_header);
191 	if (dib_header->dib_header_size != 40 || dib_header->width < 0 ||
192 	    dib_header->planes != 1 || dib_header->bpp != 24 ||
193 	    dib_header->compression != 0)
194 		goto error;
195 
196 	bmp_width = dib_header->width;
197 	bmp_height = abs(dib_header->height);
198 	bmp_pitch = round_up(3 * bmp_width, 4);
199 
200 	if ((file_header->bitmap_offset + bmp_pitch * bmp_height) >
201 				bgrt_image_size)
202 		goto error;
203 
204 	if ((bgrt_tab.image_offset_x + bmp_width) > si->lfb_width ||
205 	    (bgrt_tab.image_offset_y + bmp_height) > si->lfb_height)
206 		goto error;
207 
208 	if (!efifb_bgrt_sanity_check(si, bmp_width))
209 		goto error;
210 
211 	pr_info("efifb: showing boot graphics\n");
212 
213 	for (y = 0; y < si->lfb_height; y++, dst += si->lfb_linelength) {
214 		/* Only background? */
215 		if (y < bgrt_tab.image_offset_y ||
216 		    y >= (bgrt_tab.image_offset_y + bmp_height)) {
217 			memset(dst, 0, 4 * si->lfb_width);
218 			continue;
219 		}
220 
221 		src_y = y - bgrt_tab.image_offset_y;
222 		/* Positive header height means upside down row order */
223 		if (dib_header->height > 0)
224 			src_y = (bmp_height - 1) - src_y;
225 
226 		memset(dst, 0, bgrt_tab.image_offset_x * 4);
227 		dst_x = bgrt_tab.image_offset_x;
228 		efifb_copy_bmp(bgrt_image + file_header->bitmap_offset +
229 					    src_y * bmp_pitch,
230 			       (u32 *)dst + dst_x, bmp_width, si);
231 		dst_x += bmp_width;
232 		memset((u32 *)dst + dst_x, 0, (si->lfb_width - dst_x) * 4);
233 	}
234 
235 	memunmap(bgrt_image);
236 	return;
237 
238 error:
239 	memunmap(bgrt_image);
240 	pr_warn("efifb: Ignoring BGRT: unexpected or invalid BMP data\n");
241 }
242 #else
243 static inline void efifb_show_boot_graphics(struct fb_info *info) {}
244 #endif
245 
246 /*
247  * fb_ops.fb_destroy is called by the last put_fb_info() call at the end
248  * of unregister_framebuffer() or fb_release(). Do any cleanup here.
249  */
250 static void efifb_destroy(struct fb_info *info)
251 {
252 	if (efifb_pci_dev)
253 		pm_runtime_put(&efifb_pci_dev->dev);
254 
255 	if (info->screen_base) {
256 		if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
257 			iounmap(info->screen_base);
258 		else
259 			memunmap(info->screen_base);
260 	}
261 
262 	if (request_mem_succeeded)
263 		release_mem_region(info->apertures->ranges[0].base,
264 				   info->apertures->ranges[0].size);
265 	fb_dealloc_cmap(&info->cmap);
266 
267 	framebuffer_release(info);
268 }
269 
270 static const struct fb_ops efifb_ops = {
271 	.owner		= THIS_MODULE,
272 	.fb_destroy	= efifb_destroy,
273 	.fb_setcolreg	= efifb_setcolreg,
274 	.fb_fillrect	= cfb_fillrect,
275 	.fb_copyarea	= cfb_copyarea,
276 	.fb_imageblit	= cfb_imageblit,
277 };
278 
279 static int efifb_setup(char *options)
280 {
281 	char *this_opt;
282 
283 	if (options && *options) {
284 		while ((this_opt = strsep(&options, ",")) != NULL) {
285 			if (!*this_opt) continue;
286 
287 			efifb_setup_from_dmi(&screen_info, this_opt);
288 
289 			if (!strncmp(this_opt, "base:", 5))
290 				screen_info.lfb_base = simple_strtoul(this_opt+5, NULL, 0);
291 			else if (!strncmp(this_opt, "stride:", 7))
292 				screen_info.lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
293 			else if (!strncmp(this_opt, "height:", 7))
294 				screen_info.lfb_height = simple_strtoul(this_opt+7, NULL, 0);
295 			else if (!strncmp(this_opt, "width:", 6))
296 				screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);
297 			else if (!strcmp(this_opt, "nowc"))
298 				mem_flags &= ~EFI_MEMORY_WC;
299 			else if (!strcmp(this_opt, "nobgrt"))
300 				use_bgrt = false;
301 		}
302 	}
303 
304 	return 0;
305 }
306 
307 static inline bool fb_base_is_valid(void)
308 {
309 	if (screen_info.lfb_base)
310 		return true;
311 
312 	if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
313 		return false;
314 
315 	if (screen_info.ext_lfb_base)
316 		return true;
317 
318 	return false;
319 }
320 
321 #define efifb_attr_decl(name, fmt)					\
322 static ssize_t name##_show(struct device *dev,				\
323 			   struct device_attribute *attr,		\
324 			   char *buf)					\
325 {									\
326 	return sprintf(buf, fmt "\n", (screen_info.lfb_##name));	\
327 }									\
328 static DEVICE_ATTR_RO(name)
329 
330 efifb_attr_decl(base, "0x%x");
331 efifb_attr_decl(linelength, "%u");
332 efifb_attr_decl(height, "%u");
333 efifb_attr_decl(width, "%u");
334 efifb_attr_decl(depth, "%u");
335 
336 static struct attribute *efifb_attrs[] = {
337 	&dev_attr_base.attr,
338 	&dev_attr_linelength.attr,
339 	&dev_attr_width.attr,
340 	&dev_attr_height.attr,
341 	&dev_attr_depth.attr,
342 	NULL
343 };
344 ATTRIBUTE_GROUPS(efifb);
345 
346 static bool pci_dev_disabled;	/* FB base matches BAR of a disabled device */
347 
348 static struct resource *bar_resource;
349 static u64 bar_offset;
350 
351 static int efifb_probe(struct platform_device *dev)
352 {
353 	struct fb_info *info;
354 	int err, orientation;
355 	unsigned int size_vmode;
356 	unsigned int size_remap;
357 	unsigned int size_total;
358 	char *option = NULL;
359 	efi_memory_desc_t md;
360 
361 	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
362 		return -ENODEV;
363 
364 	if (fb_get_options("efifb", &option))
365 		return -ENODEV;
366 	efifb_setup(option);
367 
368 	/* We don't get linelength from UGA Draw Protocol, only from
369 	 * EFI Graphics Protocol.  So if it's not in DMI, and it's not
370 	 * passed in from the user, we really can't use the framebuffer.
371 	 */
372 	if (!screen_info.lfb_linelength)
373 		return -ENODEV;
374 
375 	if (!screen_info.lfb_depth)
376 		screen_info.lfb_depth = 32;
377 	if (!screen_info.pages)
378 		screen_info.pages = 1;
379 	if (!fb_base_is_valid()) {
380 		printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
381 		return -ENODEV;
382 	}
383 	printk(KERN_INFO "efifb: probing for efifb\n");
384 
385 	/* just assume they're all unset if any are */
386 	if (!screen_info.blue_size) {
387 		screen_info.blue_size = 8;
388 		screen_info.blue_pos = 0;
389 		screen_info.green_size = 8;
390 		screen_info.green_pos = 8;
391 		screen_info.red_size = 8;
392 		screen_info.red_pos = 16;
393 		screen_info.rsvd_size = 8;
394 		screen_info.rsvd_pos = 24;
395 	}
396 
397 	efifb_fix.smem_start = screen_info.lfb_base;
398 
399 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
400 		u64 ext_lfb_base;
401 
402 		ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
403 		efifb_fix.smem_start |= ext_lfb_base;
404 	}
405 
406 	if (bar_resource &&
407 	    bar_resource->start + bar_offset != efifb_fix.smem_start) {
408 		dev_info(&efifb_pci_dev->dev,
409 			 "BAR has moved, updating efifb address\n");
410 		efifb_fix.smem_start = bar_resource->start + bar_offset;
411 	}
412 
413 	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
414 	efifb_defined.xres = screen_info.lfb_width;
415 	efifb_defined.yres = screen_info.lfb_height;
416 	efifb_fix.line_length = screen_info.lfb_linelength;
417 
418 	/*   size_vmode -- that is the amount of memory needed for the
419 	 *                 used video mode, i.e. the minimum amount of
420 	 *                 memory we need. */
421 	size_vmode = efifb_defined.yres * efifb_fix.line_length;
422 
423 	/*   size_total -- all video memory we have. Used for
424 	 *                 entries, ressource allocation and bounds
425 	 *                 checking. */
426 	size_total = screen_info.lfb_size;
427 	if (size_total < size_vmode)
428 		size_total = size_vmode;
429 
430 	/*   size_remap -- the amount of video memory we are going to
431 	 *                 use for efifb.  With modern cards it is no
432 	 *                 option to simply use size_total as that
433 	 *                 wastes plenty of kernel address space. */
434 	size_remap  = size_vmode * 2;
435 	if (size_remap > size_total)
436 		size_remap = size_total;
437 	if (size_remap % PAGE_SIZE)
438 		size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
439 	efifb_fix.smem_len = size_remap;
440 
441 	if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
442 		request_mem_succeeded = true;
443 	} else {
444 		/* We cannot make this fatal. Sometimes this comes from magic
445 		   spaces our resource handlers simply don't know about */
446 		pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
447 			efifb_fix.smem_start);
448 	}
449 
450 	info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
451 	if (!info) {
452 		err = -ENOMEM;
453 		goto err_release_mem;
454 	}
455 	platform_set_drvdata(dev, info);
456 	info->pseudo_palette = info->par;
457 	info->par = NULL;
458 
459 	info->apertures = alloc_apertures(1);
460 	if (!info->apertures) {
461 		err = -ENOMEM;
462 		goto err_release_fb;
463 	}
464 	info->apertures->ranges[0].base = efifb_fix.smem_start;
465 	info->apertures->ranges[0].size = size_remap;
466 
467 	if (efi_enabled(EFI_MEMMAP) &&
468 	    !efi_mem_desc_lookup(efifb_fix.smem_start, &md)) {
469 		if ((efifb_fix.smem_start + efifb_fix.smem_len) >
470 		    (md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT))) {
471 			pr_err("efifb: video memory @ 0x%lx spans multiple EFI memory regions\n",
472 			       efifb_fix.smem_start);
473 			err = -EIO;
474 			goto err_release_fb;
475 		}
476 		/*
477 		 * If the UEFI memory map covers the efifb region, we may only
478 		 * remap it using the attributes the memory map prescribes.
479 		 */
480 		md.attribute &= EFI_MEMORY_UC | EFI_MEMORY_WC |
481 				EFI_MEMORY_WT | EFI_MEMORY_WB;
482 		if (md.attribute) {
483 			mem_flags |= EFI_MEMORY_WT | EFI_MEMORY_WB;
484 			mem_flags &= md.attribute;
485 		}
486 	}
487 	if (mem_flags & EFI_MEMORY_WC)
488 		info->screen_base = ioremap_wc(efifb_fix.smem_start,
489 					       efifb_fix.smem_len);
490 	else if (mem_flags & EFI_MEMORY_UC)
491 		info->screen_base = ioremap(efifb_fix.smem_start,
492 					    efifb_fix.smem_len);
493 	else if (mem_flags & EFI_MEMORY_WT)
494 		info->screen_base = memremap(efifb_fix.smem_start,
495 					     efifb_fix.smem_len, MEMREMAP_WT);
496 	else if (mem_flags & EFI_MEMORY_WB)
497 		info->screen_base = memremap(efifb_fix.smem_start,
498 					     efifb_fix.smem_len, MEMREMAP_WB);
499 	if (!info->screen_base) {
500 		pr_err("efifb: abort, cannot remap video memory 0x%x @ 0x%lx\n",
501 			efifb_fix.smem_len, efifb_fix.smem_start);
502 		err = -EIO;
503 		goto err_release_fb;
504 	}
505 
506 	efifb_show_boot_graphics(info);
507 
508 	pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
509 	       efifb_fix.smem_start, size_remap/1024, size_total/1024);
510 	pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
511 	       efifb_defined.xres, efifb_defined.yres,
512 	       efifb_defined.bits_per_pixel, efifb_fix.line_length,
513 	       screen_info.pages);
514 
515 	efifb_defined.xres_virtual = efifb_defined.xres;
516 	efifb_defined.yres_virtual = efifb_fix.smem_len /
517 					efifb_fix.line_length;
518 	pr_info("efifb: scrolling: redraw\n");
519 	efifb_defined.yres_virtual = efifb_defined.yres;
520 
521 	/* some dummy values for timing to make fbset happy */
522 	efifb_defined.pixclock     = 10000000 / efifb_defined.xres *
523 					1000 / efifb_defined.yres;
524 	efifb_defined.left_margin  = (efifb_defined.xres / 8) & 0xf8;
525 	efifb_defined.hsync_len    = (efifb_defined.xres / 8) & 0xf8;
526 
527 	efifb_defined.red.offset    = screen_info.red_pos;
528 	efifb_defined.red.length    = screen_info.red_size;
529 	efifb_defined.green.offset  = screen_info.green_pos;
530 	efifb_defined.green.length  = screen_info.green_size;
531 	efifb_defined.blue.offset   = screen_info.blue_pos;
532 	efifb_defined.blue.length   = screen_info.blue_size;
533 	efifb_defined.transp.offset = screen_info.rsvd_pos;
534 	efifb_defined.transp.length = screen_info.rsvd_size;
535 
536 	pr_info("efifb: %s: "
537 	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
538 	       "Truecolor",
539 	       screen_info.rsvd_size,
540 	       screen_info.red_size,
541 	       screen_info.green_size,
542 	       screen_info.blue_size,
543 	       screen_info.rsvd_pos,
544 	       screen_info.red_pos,
545 	       screen_info.green_pos,
546 	       screen_info.blue_pos);
547 
548 	efifb_fix.ypanstep  = 0;
549 	efifb_fix.ywrapstep = 0;
550 
551 	info->fbops = &efifb_ops;
552 	info->var = efifb_defined;
553 	info->fix = efifb_fix;
554 	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;
555 
556 	orientation = drm_get_panel_orientation_quirk(efifb_defined.xres,
557 						      efifb_defined.yres);
558 	switch (orientation) {
559 	default:
560 		info->fbcon_rotate_hint = FB_ROTATE_UR;
561 		break;
562 	case DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP:
563 		info->fbcon_rotate_hint = FB_ROTATE_UD;
564 		break;
565 	case DRM_MODE_PANEL_ORIENTATION_LEFT_UP:
566 		info->fbcon_rotate_hint = FB_ROTATE_CCW;
567 		break;
568 	case DRM_MODE_PANEL_ORIENTATION_RIGHT_UP:
569 		info->fbcon_rotate_hint = FB_ROTATE_CW;
570 		break;
571 	}
572 
573 	err = sysfs_create_groups(&dev->dev.kobj, efifb_groups);
574 	if (err) {
575 		pr_err("efifb: cannot add sysfs attrs\n");
576 		goto err_unmap;
577 	}
578 	err = fb_alloc_cmap(&info->cmap, 256, 0);
579 	if (err < 0) {
580 		pr_err("efifb: cannot allocate colormap\n");
581 		goto err_groups;
582 	}
583 
584 	if (efifb_pci_dev)
585 		WARN_ON(pm_runtime_get_sync(&efifb_pci_dev->dev) < 0);
586 
587 	err = register_framebuffer(info);
588 	if (err < 0) {
589 		pr_err("efifb: cannot register framebuffer\n");
590 		goto err_put_rpm_ref;
591 	}
592 	fb_info(info, "%s frame buffer device\n", info->fix.id);
593 	return 0;
594 
595 err_put_rpm_ref:
596 	if (efifb_pci_dev)
597 		pm_runtime_put(&efifb_pci_dev->dev);
598 
599 	fb_dealloc_cmap(&info->cmap);
600 err_groups:
601 	sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
602 err_unmap:
603 	if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
604 		iounmap(info->screen_base);
605 	else
606 		memunmap(info->screen_base);
607 err_release_fb:
608 	framebuffer_release(info);
609 err_release_mem:
610 	if (request_mem_succeeded)
611 		release_mem_region(efifb_fix.smem_start, size_total);
612 	return err;
613 }
614 
615 static int efifb_remove(struct platform_device *pdev)
616 {
617 	struct fb_info *info = platform_get_drvdata(pdev);
618 
619 	/* efifb_destroy takes care of info cleanup */
620 	unregister_framebuffer(info);
621 	sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
622 
623 	return 0;
624 }
625 
626 static struct platform_driver efifb_driver = {
627 	.driver = {
628 		.name = "efi-framebuffer",
629 	},
630 	.probe = efifb_probe,
631 	.remove = efifb_remove,
632 };
633 
634 builtin_platform_driver(efifb_driver);
635 
636 #if defined(CONFIG_PCI)
637 
638 static void record_efifb_bar_resource(struct pci_dev *dev, int idx, u64 offset)
639 {
640 	u16 word;
641 
642 	efifb_pci_dev = dev;
643 
644 	pci_read_config_word(dev, PCI_COMMAND, &word);
645 	if (!(word & PCI_COMMAND_MEMORY)) {
646 		pci_dev_disabled = true;
647 		dev_err(&dev->dev,
648 			"BAR %d: assigned to efifb but device is disabled!\n",
649 			idx);
650 		return;
651 	}
652 
653 	bar_resource = &dev->resource[idx];
654 	bar_offset = offset;
655 
656 	dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
657 }
658 
659 static void efifb_fixup_resources(struct pci_dev *dev)
660 {
661 	u64 base = screen_info.lfb_base;
662 	u64 size = screen_info.lfb_size;
663 	int i;
664 
665 	if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
666 		return;
667 
668 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
669 		base |= (u64)screen_info.ext_lfb_base << 32;
670 
671 	if (!base)
672 		return;
673 
674 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
675 		struct resource *res = &dev->resource[i];
676 
677 		if (!(res->flags & IORESOURCE_MEM))
678 			continue;
679 
680 		if (res->start <= base && res->end >= base + size - 1) {
681 			record_efifb_bar_resource(dev, i, base - res->start);
682 			break;
683 		}
684 	}
685 }
686 DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY,
687 			       16, efifb_fixup_resources);
688 
689 #endif
690