xref: /openbmc/linux/drivers/video/fbdev/efifb.c (revision d58f75de)
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 fb_var_screeninfo efifb_defined = {
51 	.activate		= FB_ACTIVATE_NOW,
52 	.height			= -1,
53 	.width			= -1,
54 	.right_margin		= 32,
55 	.upper_margin		= 16,
56 	.lower_margin		= 4,
57 	.vsync_len		= 4,
58 	.vmode			= FB_VMODE_NONINTERLACED,
59 };
60 
61 static struct fb_fix_screeninfo efifb_fix = {
62 	.id			= "EFI VGA",
63 	.type			= FB_TYPE_PACKED_PIXELS,
64 	.accel			= FB_ACCEL_NONE,
65 	.visual			= FB_VISUAL_TRUECOLOR,
66 };
67 
68 static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
69 			   unsigned blue, unsigned transp,
70 			   struct fb_info *info)
71 {
72 	/*
73 	 *  Set a single color register. The values supplied are
74 	 *  already rounded down to the hardware's capabilities
75 	 *  (according to the entries in the `var' structure). Return
76 	 *  != 0 for invalid regno.
77 	 */
78 
79 	if (regno >= info->cmap.len)
80 		return 1;
81 
82 	if (regno < 16) {
83 		red   >>= 16 - info->var.red.length;
84 		green >>= 16 - info->var.green.length;
85 		blue  >>= 16 - info->var.blue.length;
86 		((u32 *)(info->pseudo_palette))[regno] =
87 			(red   << info->var.red.offset)   |
88 			(green << info->var.green.offset) |
89 			(blue  << info->var.blue.offset);
90 	}
91 	return 0;
92 }
93 
94 /*
95  * If fbcon deffered console takeover is configured, the intent is for the
96  * framebuffer to show the boot graphics (e.g. vendor logo) until there is some
97  * (error) message to display. But the boot graphics may have been destroyed by
98  * e.g. option ROM output, detect this and restore the boot graphics.
99  */
100 #if defined CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER && \
101     defined CONFIG_ACPI_BGRT
102 static void efifb_copy_bmp(u8 *src, u32 *dst, int width, struct screen_info *si)
103 {
104 	u8 r, g, b;
105 
106 	while (width--) {
107 		b = *src++;
108 		g = *src++;
109 		r = *src++;
110 		*dst++ = (r << si->red_pos)   |
111 			 (g << si->green_pos) |
112 			 (b << si->blue_pos);
113 	}
114 }
115 
116 #ifdef CONFIG_X86
117 /*
118  * On x86 some firmwares use a low non native resolution for the display when
119  * they have shown some text messages. While keeping the bgrt filled with info
120  * for the native resolution. If the bgrt image intended for the native
121  * resolution still fits, it will be displayed very close to the right edge of
122  * the display looking quite bad. This function checks for this.
123  */
124 static bool efifb_bgrt_sanity_check(struct screen_info *si, u32 bmp_width)
125 {
126 	/*
127 	 * All x86 firmwares horizontally center the image (the yoffset
128 	 * calculations differ between boards, but xoffset is predictable).
129 	 */
130 	u32 expected_xoffset = (si->lfb_width - bmp_width) / 2;
131 
132 	return bgrt_tab.image_offset_x == expected_xoffset;
133 }
134 #else
135 static bool efifb_bgrt_sanity_check(struct screen_info *si, u32 bmp_width)
136 {
137 	return true;
138 }
139 #endif
140 
141 static void efifb_show_boot_graphics(struct fb_info *info)
142 {
143 	u32 bmp_width, bmp_height, bmp_pitch, dst_x, y, src_y;
144 	struct screen_info *si = &screen_info;
145 	struct bmp_file_header *file_header;
146 	struct bmp_dib_header *dib_header;
147 	void *bgrt_image = NULL;
148 	u8 *dst = info->screen_base;
149 
150 	if (!use_bgrt)
151 		return;
152 
153 	if (!bgrt_tab.image_address) {
154 		pr_info("efifb: No BGRT, not showing boot graphics\n");
155 		return;
156 	}
157 
158 	if (bgrt_tab.status & 0x06) {
159 		pr_info("efifb: BGRT rotation bits set, not showing boot graphics\n");
160 		return;
161 	}
162 
163 	/* Avoid flashing the logo if we're going to print std probe messages */
164 	if (console_loglevel > CONSOLE_LOGLEVEL_QUIET)
165 		return;
166 
167 	/* bgrt_tab.status is unreliable, so we don't check it */
168 
169 	if (si->lfb_depth != 32) {
170 		pr_info("efifb: not 32 bits, not showing boot graphics\n");
171 		return;
172 	}
173 
174 	bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
175 			      MEMREMAP_WB);
176 	if (!bgrt_image) {
177 		pr_warn("efifb: Ignoring BGRT: failed to map image memory\n");
178 		return;
179 	}
180 
181 	if (bgrt_image_size < (sizeof(*file_header) + sizeof(*dib_header)))
182 		goto error;
183 
184 	file_header = bgrt_image;
185 	if (file_header->id != 0x4d42 || file_header->reserved != 0)
186 		goto error;
187 
188 	dib_header = bgrt_image + sizeof(*file_header);
189 	if (dib_header->dib_header_size != 40 || dib_header->width < 0 ||
190 	    dib_header->planes != 1 || dib_header->bpp != 24 ||
191 	    dib_header->compression != 0)
192 		goto error;
193 
194 	bmp_width = dib_header->width;
195 	bmp_height = abs(dib_header->height);
196 	bmp_pitch = round_up(3 * bmp_width, 4);
197 
198 	if ((file_header->bitmap_offset + bmp_pitch * bmp_height) >
199 				bgrt_image_size)
200 		goto error;
201 
202 	if ((bgrt_tab.image_offset_x + bmp_width) > si->lfb_width ||
203 	    (bgrt_tab.image_offset_y + bmp_height) > si->lfb_height)
204 		goto error;
205 
206 	if (!efifb_bgrt_sanity_check(si, bmp_width))
207 		goto error;
208 
209 	pr_info("efifb: showing boot graphics\n");
210 
211 	for (y = 0; y < si->lfb_height; y++, dst += si->lfb_linelength) {
212 		/* Only background? */
213 		if (y < bgrt_tab.image_offset_y ||
214 		    y >= (bgrt_tab.image_offset_y + bmp_height)) {
215 			memset(dst, 0, 4 * si->lfb_width);
216 			continue;
217 		}
218 
219 		src_y = y - bgrt_tab.image_offset_y;
220 		/* Positive header height means upside down row order */
221 		if (dib_header->height > 0)
222 			src_y = (bmp_height - 1) - src_y;
223 
224 		memset(dst, 0, bgrt_tab.image_offset_x * 4);
225 		dst_x = bgrt_tab.image_offset_x;
226 		efifb_copy_bmp(bgrt_image + file_header->bitmap_offset +
227 					    src_y * bmp_pitch,
228 			       (u32 *)dst + dst_x, bmp_width, si);
229 		dst_x += bmp_width;
230 		memset((u32 *)dst + dst_x, 0, (si->lfb_width - dst_x) * 4);
231 	}
232 
233 	memunmap(bgrt_image);
234 	return;
235 
236 error:
237 	memunmap(bgrt_image);
238 	pr_warn("efifb: Ignoring BGRT: unexpected or invalid BMP data\n");
239 }
240 #else
241 static inline void efifb_show_boot_graphics(struct fb_info *info) {}
242 #endif
243 
244 static void efifb_destroy(struct fb_info *info)
245 {
246 	if (info->screen_base) {
247 		if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
248 			iounmap(info->screen_base);
249 		else
250 			memunmap(info->screen_base);
251 	}
252 	if (request_mem_succeeded)
253 		release_mem_region(info->apertures->ranges[0].base,
254 				   info->apertures->ranges[0].size);
255 	fb_dealloc_cmap(&info->cmap);
256 }
257 
258 static const struct fb_ops efifb_ops = {
259 	.owner		= THIS_MODULE,
260 	.fb_destroy	= efifb_destroy,
261 	.fb_setcolreg	= efifb_setcolreg,
262 	.fb_fillrect	= cfb_fillrect,
263 	.fb_copyarea	= cfb_copyarea,
264 	.fb_imageblit	= cfb_imageblit,
265 };
266 
267 static int efifb_setup(char *options)
268 {
269 	char *this_opt;
270 
271 	if (options && *options) {
272 		while ((this_opt = strsep(&options, ",")) != NULL) {
273 			if (!*this_opt) continue;
274 
275 			efifb_setup_from_dmi(&screen_info, this_opt);
276 
277 			if (!strncmp(this_opt, "base:", 5))
278 				screen_info.lfb_base = simple_strtoul(this_opt+5, NULL, 0);
279 			else if (!strncmp(this_opt, "stride:", 7))
280 				screen_info.lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
281 			else if (!strncmp(this_opt, "height:", 7))
282 				screen_info.lfb_height = simple_strtoul(this_opt+7, NULL, 0);
283 			else if (!strncmp(this_opt, "width:", 6))
284 				screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);
285 			else if (!strcmp(this_opt, "nowc"))
286 				mem_flags &= ~EFI_MEMORY_WC;
287 			else if (!strcmp(this_opt, "nobgrt"))
288 				use_bgrt = false;
289 		}
290 	}
291 
292 	return 0;
293 }
294 
295 static inline bool fb_base_is_valid(void)
296 {
297 	if (screen_info.lfb_base)
298 		return true;
299 
300 	if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
301 		return false;
302 
303 	if (screen_info.ext_lfb_base)
304 		return true;
305 
306 	return false;
307 }
308 
309 #define efifb_attr_decl(name, fmt)					\
310 static ssize_t name##_show(struct device *dev,				\
311 			   struct device_attribute *attr,		\
312 			   char *buf)					\
313 {									\
314 	return sprintf(buf, fmt "\n", (screen_info.lfb_##name));	\
315 }									\
316 static DEVICE_ATTR_RO(name)
317 
318 efifb_attr_decl(base, "0x%x");
319 efifb_attr_decl(linelength, "%u");
320 efifb_attr_decl(height, "%u");
321 efifb_attr_decl(width, "%u");
322 efifb_attr_decl(depth, "%u");
323 
324 static struct attribute *efifb_attrs[] = {
325 	&dev_attr_base.attr,
326 	&dev_attr_linelength.attr,
327 	&dev_attr_width.attr,
328 	&dev_attr_height.attr,
329 	&dev_attr_depth.attr,
330 	NULL
331 };
332 ATTRIBUTE_GROUPS(efifb);
333 
334 static bool pci_dev_disabled;	/* FB base matches BAR of a disabled device */
335 
336 static struct pci_dev *efifb_pci_dev;	/* dev with BAR covering the efifb */
337 static struct resource *bar_resource;
338 static u64 bar_offset;
339 
340 static int efifb_probe(struct platform_device *dev)
341 {
342 	struct fb_info *info;
343 	int err, orientation;
344 	unsigned int size_vmode;
345 	unsigned int size_remap;
346 	unsigned int size_total;
347 	char *option = NULL;
348 	efi_memory_desc_t md;
349 
350 	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
351 		return -ENODEV;
352 
353 	if (fb_get_options("efifb", &option))
354 		return -ENODEV;
355 	efifb_setup(option);
356 
357 	/* We don't get linelength from UGA Draw Protocol, only from
358 	 * EFI Graphics Protocol.  So if it's not in DMI, and it's not
359 	 * passed in from the user, we really can't use the framebuffer.
360 	 */
361 	if (!screen_info.lfb_linelength)
362 		return -ENODEV;
363 
364 	if (!screen_info.lfb_depth)
365 		screen_info.lfb_depth = 32;
366 	if (!screen_info.pages)
367 		screen_info.pages = 1;
368 	if (!fb_base_is_valid()) {
369 		printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
370 		return -ENODEV;
371 	}
372 	printk(KERN_INFO "efifb: probing for efifb\n");
373 
374 	/* just assume they're all unset if any are */
375 	if (!screen_info.blue_size) {
376 		screen_info.blue_size = 8;
377 		screen_info.blue_pos = 0;
378 		screen_info.green_size = 8;
379 		screen_info.green_pos = 8;
380 		screen_info.red_size = 8;
381 		screen_info.red_pos = 16;
382 		screen_info.rsvd_size = 8;
383 		screen_info.rsvd_pos = 24;
384 	}
385 
386 	efifb_fix.smem_start = screen_info.lfb_base;
387 
388 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
389 		u64 ext_lfb_base;
390 
391 		ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
392 		efifb_fix.smem_start |= ext_lfb_base;
393 	}
394 
395 	if (bar_resource &&
396 	    bar_resource->start + bar_offset != efifb_fix.smem_start) {
397 		dev_info(&efifb_pci_dev->dev,
398 			 "BAR has moved, updating efifb address\n");
399 		efifb_fix.smem_start = bar_resource->start + bar_offset;
400 	}
401 
402 	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
403 	efifb_defined.xres = screen_info.lfb_width;
404 	efifb_defined.yres = screen_info.lfb_height;
405 	efifb_fix.line_length = screen_info.lfb_linelength;
406 
407 	/*   size_vmode -- that is the amount of memory needed for the
408 	 *                 used video mode, i.e. the minimum amount of
409 	 *                 memory we need. */
410 	size_vmode = efifb_defined.yres * efifb_fix.line_length;
411 
412 	/*   size_total -- all video memory we have. Used for
413 	 *                 entries, ressource allocation and bounds
414 	 *                 checking. */
415 	size_total = screen_info.lfb_size;
416 	if (size_total < size_vmode)
417 		size_total = size_vmode;
418 
419 	/*   size_remap -- the amount of video memory we are going to
420 	 *                 use for efifb.  With modern cards it is no
421 	 *                 option to simply use size_total as that
422 	 *                 wastes plenty of kernel address space. */
423 	size_remap  = size_vmode * 2;
424 	if (size_remap > size_total)
425 		size_remap = size_total;
426 	if (size_remap % PAGE_SIZE)
427 		size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
428 	efifb_fix.smem_len = size_remap;
429 
430 	if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
431 		request_mem_succeeded = true;
432 	} else {
433 		/* We cannot make this fatal. Sometimes this comes from magic
434 		   spaces our resource handlers simply don't know about */
435 		pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
436 			efifb_fix.smem_start);
437 	}
438 
439 	info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
440 	if (!info) {
441 		err = -ENOMEM;
442 		goto err_release_mem;
443 	}
444 	platform_set_drvdata(dev, info);
445 	info->pseudo_palette = info->par;
446 	info->par = NULL;
447 
448 	info->apertures = alloc_apertures(1);
449 	if (!info->apertures) {
450 		err = -ENOMEM;
451 		goto err_release_fb;
452 	}
453 	info->apertures->ranges[0].base = efifb_fix.smem_start;
454 	info->apertures->ranges[0].size = size_remap;
455 
456 	if (efi_enabled(EFI_MEMMAP) &&
457 	    !efi_mem_desc_lookup(efifb_fix.smem_start, &md)) {
458 		if ((efifb_fix.smem_start + efifb_fix.smem_len) >
459 		    (md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT))) {
460 			pr_err("efifb: video memory @ 0x%lx spans multiple EFI memory regions\n",
461 			       efifb_fix.smem_start);
462 			err = -EIO;
463 			goto err_release_fb;
464 		}
465 		/*
466 		 * If the UEFI memory map covers the efifb region, we may only
467 		 * remap it using the attributes the memory map prescribes.
468 		 */
469 		md.attribute &= EFI_MEMORY_UC | EFI_MEMORY_WC |
470 				EFI_MEMORY_WT | EFI_MEMORY_WB;
471 		if (md.attribute) {
472 			mem_flags |= EFI_MEMORY_WT | EFI_MEMORY_WB;
473 			mem_flags &= md.attribute;
474 		}
475 	}
476 	if (mem_flags & EFI_MEMORY_WC)
477 		info->screen_base = ioremap_wc(efifb_fix.smem_start,
478 					       efifb_fix.smem_len);
479 	else if (mem_flags & EFI_MEMORY_UC)
480 		info->screen_base = ioremap(efifb_fix.smem_start,
481 					    efifb_fix.smem_len);
482 	else if (mem_flags & EFI_MEMORY_WT)
483 		info->screen_base = memremap(efifb_fix.smem_start,
484 					     efifb_fix.smem_len, MEMREMAP_WT);
485 	else if (mem_flags & EFI_MEMORY_WB)
486 		info->screen_base = memremap(efifb_fix.smem_start,
487 					     efifb_fix.smem_len, MEMREMAP_WB);
488 	if (!info->screen_base) {
489 		pr_err("efifb: abort, cannot remap video memory 0x%x @ 0x%lx\n",
490 			efifb_fix.smem_len, efifb_fix.smem_start);
491 		err = -EIO;
492 		goto err_release_fb;
493 	}
494 
495 	efifb_show_boot_graphics(info);
496 
497 	pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
498 	       efifb_fix.smem_start, size_remap/1024, size_total/1024);
499 	pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
500 	       efifb_defined.xres, efifb_defined.yres,
501 	       efifb_defined.bits_per_pixel, efifb_fix.line_length,
502 	       screen_info.pages);
503 
504 	efifb_defined.xres_virtual = efifb_defined.xres;
505 	efifb_defined.yres_virtual = efifb_fix.smem_len /
506 					efifb_fix.line_length;
507 	pr_info("efifb: scrolling: redraw\n");
508 	efifb_defined.yres_virtual = efifb_defined.yres;
509 
510 	/* some dummy values for timing to make fbset happy */
511 	efifb_defined.pixclock     = 10000000 / efifb_defined.xres *
512 					1000 / efifb_defined.yres;
513 	efifb_defined.left_margin  = (efifb_defined.xres / 8) & 0xf8;
514 	efifb_defined.hsync_len    = (efifb_defined.xres / 8) & 0xf8;
515 
516 	efifb_defined.red.offset    = screen_info.red_pos;
517 	efifb_defined.red.length    = screen_info.red_size;
518 	efifb_defined.green.offset  = screen_info.green_pos;
519 	efifb_defined.green.length  = screen_info.green_size;
520 	efifb_defined.blue.offset   = screen_info.blue_pos;
521 	efifb_defined.blue.length   = screen_info.blue_size;
522 	efifb_defined.transp.offset = screen_info.rsvd_pos;
523 	efifb_defined.transp.length = screen_info.rsvd_size;
524 
525 	pr_info("efifb: %s: "
526 	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
527 	       "Truecolor",
528 	       screen_info.rsvd_size,
529 	       screen_info.red_size,
530 	       screen_info.green_size,
531 	       screen_info.blue_size,
532 	       screen_info.rsvd_pos,
533 	       screen_info.red_pos,
534 	       screen_info.green_pos,
535 	       screen_info.blue_pos);
536 
537 	efifb_fix.ypanstep  = 0;
538 	efifb_fix.ywrapstep = 0;
539 
540 	info->fbops = &efifb_ops;
541 	info->var = efifb_defined;
542 	info->fix = efifb_fix;
543 	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;
544 
545 	orientation = drm_get_panel_orientation_quirk(efifb_defined.xres,
546 						      efifb_defined.yres);
547 	switch (orientation) {
548 	default:
549 		info->fbcon_rotate_hint = FB_ROTATE_UR;
550 		break;
551 	case DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP:
552 		info->fbcon_rotate_hint = FB_ROTATE_UD;
553 		break;
554 	case DRM_MODE_PANEL_ORIENTATION_LEFT_UP:
555 		info->fbcon_rotate_hint = FB_ROTATE_CCW;
556 		break;
557 	case DRM_MODE_PANEL_ORIENTATION_RIGHT_UP:
558 		info->fbcon_rotate_hint = FB_ROTATE_CW;
559 		break;
560 	}
561 
562 	err = sysfs_create_groups(&dev->dev.kobj, efifb_groups);
563 	if (err) {
564 		pr_err("efifb: cannot add sysfs attrs\n");
565 		goto err_unmap;
566 	}
567 	err = fb_alloc_cmap(&info->cmap, 256, 0);
568 	if (err < 0) {
569 		pr_err("efifb: cannot allocate colormap\n");
570 		goto err_groups;
571 	}
572 	err = register_framebuffer(info);
573 	if (err < 0) {
574 		pr_err("efifb: cannot register framebuffer\n");
575 		goto err_fb_dealoc;
576 	}
577 	fb_info(info, "%s frame buffer device\n", info->fix.id);
578 	if (efifb_pci_dev)
579 		pm_runtime_get_sync(&efifb_pci_dev->dev);
580 	return 0;
581 
582 err_fb_dealoc:
583 	fb_dealloc_cmap(&info->cmap);
584 err_groups:
585 	sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
586 err_unmap:
587 	if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC))
588 		iounmap(info->screen_base);
589 	else
590 		memunmap(info->screen_base);
591 err_release_fb:
592 	framebuffer_release(info);
593 err_release_mem:
594 	if (request_mem_succeeded)
595 		release_mem_region(efifb_fix.smem_start, size_total);
596 	return err;
597 }
598 
599 static int efifb_remove(struct platform_device *pdev)
600 {
601 	struct fb_info *info = platform_get_drvdata(pdev);
602 
603 	unregister_framebuffer(info);
604 	sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
605 	framebuffer_release(info);
606 	if (efifb_pci_dev)
607 		pm_runtime_put(&efifb_pci_dev->dev);
608 
609 	return 0;
610 }
611 
612 static struct platform_driver efifb_driver = {
613 	.driver = {
614 		.name = "efi-framebuffer",
615 	},
616 	.probe = efifb_probe,
617 	.remove = efifb_remove,
618 };
619 
620 builtin_platform_driver(efifb_driver);
621 
622 #if defined(CONFIG_PCI)
623 
624 static void record_efifb_bar_resource(struct pci_dev *dev, int idx, u64 offset)
625 {
626 	u16 word;
627 
628 	efifb_pci_dev = dev;
629 
630 	pci_read_config_word(dev, PCI_COMMAND, &word);
631 	if (!(word & PCI_COMMAND_MEMORY)) {
632 		pci_dev_disabled = true;
633 		dev_err(&dev->dev,
634 			"BAR %d: assigned to efifb but device is disabled!\n",
635 			idx);
636 		return;
637 	}
638 
639 	bar_resource = &dev->resource[idx];
640 	bar_offset = offset;
641 
642 	dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
643 }
644 
645 static void efifb_fixup_resources(struct pci_dev *dev)
646 {
647 	u64 base = screen_info.lfb_base;
648 	u64 size = screen_info.lfb_size;
649 	int i;
650 
651 	if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
652 		return;
653 
654 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
655 		base |= (u64)screen_info.ext_lfb_base << 32;
656 
657 	if (!base)
658 		return;
659 
660 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
661 		struct resource *res = &dev->resource[i];
662 
663 		if (!(res->flags & IORESOURCE_MEM))
664 			continue;
665 
666 		if (res->start <= base && res->end >= base + size - 1) {
667 			record_efifb_bar_resource(dev, i, base - res->start);
668 			break;
669 		}
670 	}
671 }
672 DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY,
673 			       16, efifb_fixup_resources);
674 
675 #endif
676