xref: /linux/drivers/video/fbdev/efifb.c (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
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 
efifb_setcolreg(unsigned regno,unsigned red,unsigned green,unsigned blue,unsigned transp,struct fb_info * info)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
efifb_copy_bmp(u8 * src,u32 * dst,int width,const struct screen_info * si)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  */
efifb_bgrt_sanity_check(const struct screen_info * si,u32 bmp_width)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
efifb_bgrt_sanity_check(const struct screen_info * si,u32 bmp_width)140 static bool efifb_bgrt_sanity_check(const struct screen_info *si, u32 bmp_width)
141 {
142 	return true;
143 }
144 #endif
145 
efifb_show_boot_graphics(struct fb_info * info,const struct screen_info * si)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
efifb_show_boot_graphics(struct fb_info * info,const struct screen_info * si)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  */
efifb_destroy(struct fb_info * info)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 
efifb_setup(struct screen_info * si,char * options)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 
fb_base_is_valid(struct screen_info * si)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_drvdata(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 
efifb_probe(struct platform_device * dev)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 	dev_set_drvdata(&dev->dev, si);
373 
374 	if (si->orig_video_isVGA != VIDEO_TYPE_EFI)
375 		return -ENODEV;
376 
377 	if (fb_get_options("efifb", &option))
378 		return -ENODEV;
379 	efifb_setup(si, option);
380 
381 	/* We don't get linelength from UGA Draw Protocol, only from
382 	 * EFI Graphics Protocol.  So if it's not in DMI, and it's not
383 	 * passed in from the user, we really can't use the framebuffer.
384 	 */
385 	if (!si->lfb_linelength)
386 		return -ENODEV;
387 
388 	if (!si->lfb_depth)
389 		si->lfb_depth = 32;
390 	if (!si->pages)
391 		si->pages = 1;
392 	if (!fb_base_is_valid(si)) {
393 		printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
394 		return -ENODEV;
395 	}
396 	printk(KERN_INFO "efifb: probing for efifb\n");
397 
398 	/* just assume they're all unset if any are */
399 	if (!si->blue_size) {
400 		si->blue_size = 8;
401 		si->blue_pos = 0;
402 		si->green_size = 8;
403 		si->green_pos = 8;
404 		si->red_size = 8;
405 		si->red_pos = 16;
406 		si->rsvd_size = 8;
407 		si->rsvd_pos = 24;
408 	}
409 
410 	efifb_fix.smem_start = __screen_info_lfb_base(si);
411 
412 	efifb_defined.bits_per_pixel = si->lfb_depth;
413 	efifb_defined.xres = si->lfb_width;
414 	efifb_defined.yres = si->lfb_height;
415 	efifb_fix.line_length = si->lfb_linelength;
416 
417 	/*   size_vmode -- that is the amount of memory needed for the
418 	 *                 used video mode, i.e. the minimum amount of
419 	 *                 memory we need. */
420 	size_vmode = efifb_defined.yres * efifb_fix.line_length;
421 
422 	/*   size_total -- all video memory we have. Used for
423 	 *                 entries, ressource allocation and bounds
424 	 *                 checking. */
425 	size_total = si->lfb_size;
426 	if (size_total < size_vmode)
427 		size_total = size_vmode;
428 
429 	/*   size_remap -- the amount of video memory we are going to
430 	 *                 use for efifb.  With modern cards it is no
431 	 *                 option to simply use size_total as that
432 	 *                 wastes plenty of kernel address space. */
433 	size_remap  = size_vmode * 2;
434 	if (size_remap > size_total)
435 		size_remap = size_total;
436 	if (size_remap % PAGE_SIZE)
437 		size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
438 	efifb_fix.smem_len = size_remap;
439 
440 	if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
441 		request_mem_succeeded = true;
442 	} else {
443 		/* We cannot make this fatal. Sometimes this comes from magic
444 		   spaces our resource handlers simply don't know about */
445 		pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
446 			efifb_fix.smem_start);
447 	}
448 
449 	info = framebuffer_alloc(sizeof(*par), &dev->dev);
450 	if (!info) {
451 		err = -ENOMEM;
452 		goto err_release_mem;
453 	}
454 	par = info->par;
455 	info->pseudo_palette = par->pseudo_palette;
456 
457 	par->base = efifb_fix.smem_start;
458 	par->size = size_remap;
459 
460 	if (efi_enabled(EFI_MEMMAP) &&
461 	    !efi_mem_desc_lookup(efifb_fix.smem_start, &md)) {
462 		if ((efifb_fix.smem_start + efifb_fix.smem_len) >
463 		    (md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT))) {
464 			pr_err("efifb: video memory @ 0x%lx spans multiple EFI memory regions\n",
465 			       efifb_fix.smem_start);
466 			err = -EIO;
467 			goto err_release_fb;
468 		}
469 		/*
470 		 * If the UEFI memory map covers the efifb region, we may only
471 		 * remap it using the attributes the memory map prescribes.
472 		 */
473 		md.attribute &= EFI_MEMORY_UC | EFI_MEMORY_WC |
474 				EFI_MEMORY_WT | EFI_MEMORY_WB;
475 		if (md.attribute) {
476 			mem_flags |= EFI_MEMORY_WT | EFI_MEMORY_WB;
477 			mem_flags &= md.attribute;
478 		}
479 	}
480 	if (mem_flags & EFI_MEMORY_WC)
481 		info->screen_base = ioremap_wc(efifb_fix.smem_start,
482 					       efifb_fix.smem_len);
483 	else if (mem_flags & EFI_MEMORY_UC)
484 		info->screen_base = ioremap(efifb_fix.smem_start,
485 					    efifb_fix.smem_len);
486 	else if (mem_flags & EFI_MEMORY_WT)
487 		info->screen_base = memremap(efifb_fix.smem_start,
488 					     efifb_fix.smem_len, MEMREMAP_WT);
489 	else if (mem_flags & EFI_MEMORY_WB)
490 		info->screen_base = memremap(efifb_fix.smem_start,
491 					     efifb_fix.smem_len, MEMREMAP_WB);
492 	if (!info->screen_base) {
493 		pr_err("efifb: abort, cannot remap video memory 0x%x @ 0x%lx\n",
494 			efifb_fix.smem_len, efifb_fix.smem_start);
495 		err = -EIO;
496 		goto err_release_fb;
497 	}
498 
499 	efifb_show_boot_graphics(info, si);
500 
501 	pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
502 	       efifb_fix.smem_start, size_remap/1024, size_total/1024);
503 	pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
504 	       efifb_defined.xres, efifb_defined.yres,
505 	       efifb_defined.bits_per_pixel, efifb_fix.line_length,
506 	       si->pages);
507 
508 	efifb_defined.xres_virtual = efifb_defined.xres;
509 	efifb_defined.yres_virtual = efifb_fix.smem_len /
510 					efifb_fix.line_length;
511 	pr_info("efifb: scrolling: redraw\n");
512 	efifb_defined.yres_virtual = efifb_defined.yres;
513 
514 	/* some dummy values for timing to make fbset happy */
515 	efifb_defined.pixclock     = 10000000 / efifb_defined.xres *
516 					1000 / efifb_defined.yres;
517 	efifb_defined.left_margin  = (efifb_defined.xres / 8) & 0xf8;
518 	efifb_defined.hsync_len    = (efifb_defined.xres / 8) & 0xf8;
519 
520 	efifb_defined.red.offset    = si->red_pos;
521 	efifb_defined.red.length    = si->red_size;
522 	efifb_defined.green.offset  = si->green_pos;
523 	efifb_defined.green.length  = si->green_size;
524 	efifb_defined.blue.offset   = si->blue_pos;
525 	efifb_defined.blue.length   = si->blue_size;
526 	efifb_defined.transp.offset = si->rsvd_pos;
527 	efifb_defined.transp.length = si->rsvd_size;
528 
529 	pr_info("efifb: %s: "
530 	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
531 	       "Truecolor",
532 	       si->rsvd_size,
533 	       si->red_size,
534 	       si->green_size,
535 	       si->blue_size,
536 	       si->rsvd_pos,
537 	       si->red_pos,
538 	       si->green_pos,
539 	       si->blue_pos);
540 
541 	efifb_fix.ypanstep  = 0;
542 	efifb_fix.ywrapstep = 0;
543 
544 	info->fbops = &efifb_ops;
545 	info->var = efifb_defined;
546 	info->fix = efifb_fix;
547 
548 	orientation = drm_get_panel_orientation_quirk(efifb_defined.xres,
549 						      efifb_defined.yres);
550 	switch (orientation) {
551 	default:
552 		info->fbcon_rotate_hint = FB_ROTATE_UR;
553 		break;
554 	case DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP:
555 		info->fbcon_rotate_hint = FB_ROTATE_UD;
556 		break;
557 	case DRM_MODE_PANEL_ORIENTATION_LEFT_UP:
558 		info->fbcon_rotate_hint = FB_ROTATE_CCW;
559 		break;
560 	case DRM_MODE_PANEL_ORIENTATION_RIGHT_UP:
561 		info->fbcon_rotate_hint = FB_ROTATE_CW;
562 		break;
563 	}
564 
565 	err = fb_alloc_cmap(&info->cmap, 256, 0);
566 	if (err < 0) {
567 		pr_err("efifb: cannot allocate colormap\n");
568 		goto err_unmap;
569 	}
570 
571 	err = devm_aperture_acquire_for_platform_device(dev, par->base, par->size);
572 	if (err) {
573 		pr_err("efifb: cannot acquire aperture\n");
574 		goto err_fb_dealloc_cmap;
575 	}
576 	err = devm_register_framebuffer(&dev->dev, info);
577 	if (err < 0) {
578 		pr_err("efifb: cannot register framebuffer\n");
579 		goto err_fb_dealloc_cmap;
580 	}
581 	fb_info(info, "%s frame buffer device\n", info->fix.id);
582 	return 0;
583 
584 err_fb_dealloc_cmap:
585 	fb_dealloc_cmap(&info->cmap);
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 struct platform_driver efifb_driver = {
600 	.driver = {
601 		.name = "efi-framebuffer",
602 		.dev_groups = efifb_groups,
603 	},
604 	.probe = efifb_probe,
605 };
606 
607 builtin_platform_driver(efifb_driver);
608