drivers/video/fbdev/efifb.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Framebuffer driver for EFI/UEFI based system
  *
  * (c) 2006 Edgar Hucek <gimli@dark-green.com>
  * Original efi driver written by Gerd Knorr <kraxel@goldbach.in-berlin.de>
  *
  */

 #include <linux/kernel.h>
 #include <linux/efi.h>
 #include <linux/errno.h>
 #include <linux/fb.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/screen_info.h>
 #include <video/vga.h>
 #include <asm/efi.h>
 #include <drm/drm_utils.h> /* For drm_get_panel_orientation_quirk */
 #include <drm/drm_connector.h>  /* For DRM_MODE_PANEL_ORIENTATION_* */

 static bool request_mem_succeeded = false;
 static bool nowc = false;

 static struct fb_var_screeninfo efifb_defined = {
 	.activate		= FB_ACTIVATE_NOW,
 	.height			= -1,
 	.width			= -1,
 	.right_margin		= 32,
 	.upper_margin		= 16,
 	.lower_margin		= 4,
 	.vsync_len		= 4,
 	.vmode			= FB_VMODE_NONINTERLACED,
 };

 static struct fb_fix_screeninfo efifb_fix = {
 	.id			= "EFI VGA",
 	.type			= FB_TYPE_PACKED_PIXELS,
 	.accel			= FB_ACCEL_NONE,
 	.visual			= FB_VISUAL_TRUECOLOR,
 };

 static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
 			   unsigned blue, unsigned transp,
 			   struct fb_info *info)
 {
 	/*
 	 *  Set a single color register. The values supplied are
 	 *  already rounded down to the hardware's capabilities
 	 *  (according to the entries in the `var' structure). Return
 	 *  != 0 for invalid regno.
 	 */

 	if (regno >= info->cmap.len)
 		return 1;

 	if (regno < 16) {
 		red   >>= 16 - info->var.red.length;
 		green >>= 16 - info->var.green.length;
 		blue  >>= 16 - info->var.blue.length;
 		((u32 *)(info->pseudo_palette))[regno] =
 			(red   << info->var.red.offset)   |
 			(green << info->var.green.offset) |
 			(blue  << info->var.blue.offset);
 	}
 	return 0;
 }

 static void efifb_destroy(struct fb_info *info)
 {
 	if (info->screen_base)
 		iounmap(info->screen_base);
 	if (request_mem_succeeded)
 		release_mem_region(info->apertures->ranges[0].base,
 				   info->apertures->ranges[0].size);
 	fb_dealloc_cmap(&info->cmap);
 }

 static struct fb_ops efifb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_destroy	= efifb_destroy,
 	.fb_setcolreg	= efifb_setcolreg,
 	.fb_fillrect	= cfb_fillrect,
 	.fb_copyarea	= cfb_copyarea,
 	.fb_imageblit	= cfb_imageblit,
 };

 static int efifb_setup(char *options)
 {
 	char *this_opt;

 	if (options && *options) {
 		while ((this_opt = strsep(&options, ",")) != NULL) {
 			if (!*this_opt) continue;

 			efifb_setup_from_dmi(&screen_info, this_opt);

 			if (!strncmp(this_opt, "base:", 5))
 				screen_info.lfb_base = simple_strtoul(this_opt+5, NULL, 0);
 			else if (!strncmp(this_opt, "stride:", 7))
 				screen_info.lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
 			else if (!strncmp(this_opt, "height:", 7))
 				screen_info.lfb_height = simple_strtoul(this_opt+7, NULL, 0);
 			else if (!strncmp(this_opt, "width:", 6))
 				screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);
 			else if (!strcmp(this_opt, "nowc"))
 				nowc = true;
 		}
 	}

 	return 0;
 }

 static inline bool fb_base_is_valid(void)
 {
 	if (screen_info.lfb_base)
 		return true;

 	if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
 		return false;

 	if (screen_info.ext_lfb_base)
 		return true;

 	return false;
 }

 #define efifb_attr_decl(name, fmt)					\
 static ssize_t name##_show(struct device *dev,				\
 			   struct device_attribute *attr,		\
 			   char *buf)					\
 {									\
 	return sprintf(buf, fmt "\n", (screen_info.lfb_##name));	\
 }									\
 static DEVICE_ATTR_RO(name)

 efifb_attr_decl(base, "0x%x");
 efifb_attr_decl(linelength, "%u");
 efifb_attr_decl(height, "%u");
 efifb_attr_decl(width, "%u");
 efifb_attr_decl(depth, "%u");

 static struct attribute *efifb_attrs[] = {
 	&dev_attr_base.attr,
 	&dev_attr_linelength.attr,
 	&dev_attr_width.attr,
 	&dev_attr_height.attr,
 	&dev_attr_depth.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(efifb);

 static bool pci_dev_disabled;	/* FB base matches BAR of a disabled device */

 static struct pci_dev *efifb_pci_dev;	/* dev with BAR covering the efifb */
 static struct resource *bar_resource;
 static u64 bar_offset;

 static int efifb_probe(struct platform_device *dev)
 {
 	struct fb_info *info;
 	int err, orientation;
 	unsigned int size_vmode;
 	unsigned int size_remap;
 	unsigned int size_total;
 	char *option = NULL;

 	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
 		return -ENODEV;

 	if (fb_get_options("efifb", &option))
 		return -ENODEV;
 	efifb_setup(option);

 	/* We don't get linelength from UGA Draw Protocol, only from
 	 * EFI Graphics Protocol.  So if it's not in DMI, and it's not
 	 * passed in from the user, we really can't use the framebuffer.
 	 */
 	if (!screen_info.lfb_linelength)
 		return -ENODEV;

 	if (!screen_info.lfb_depth)
 		screen_info.lfb_depth = 32;
 	if (!screen_info.pages)
 		screen_info.pages = 1;
 	if (!fb_base_is_valid()) {
 		printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
 		return -ENODEV;
 	}
 	printk(KERN_INFO "efifb: probing for efifb\n");

 	/* just assume they're all unset if any are */
 	if (!screen_info.blue_size) {
 		screen_info.blue_size = 8;
 		screen_info.blue_pos = 0;
 		screen_info.green_size = 8;
 		screen_info.green_pos = 8;
 		screen_info.red_size = 8;
 		screen_info.red_pos = 16;
 		screen_info.rsvd_size = 8;
 		screen_info.rsvd_pos = 24;
 	}

 	efifb_fix.smem_start = screen_info.lfb_base;

 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
 		u64 ext_lfb_base;

 		ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
 		efifb_fix.smem_start |= ext_lfb_base;
 	}

 	if (bar_resource &&
 	    bar_resource->start + bar_offset != efifb_fix.smem_start) {
 		dev_info(&efifb_pci_dev->dev,
 			 "BAR has moved, updating efifb address\n");
 		efifb_fix.smem_start = bar_resource->start + bar_offset;
 	}

 	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
 	efifb_defined.xres = screen_info.lfb_width;
 	efifb_defined.yres = screen_info.lfb_height;
 	efifb_fix.line_length = screen_info.lfb_linelength;

 	/*   size_vmode -- that is the amount of memory needed for the
 	 *                 used video mode, i.e. the minimum amount of
 	 *                 memory we need. */
 	size_vmode = efifb_defined.yres * efifb_fix.line_length;

 	/*   size_total -- all video memory we have. Used for
 	 *                 entries, ressource allocation and bounds
 	 *                 checking. */
 	size_total = screen_info.lfb_size;
 	if (size_total < size_vmode)
 		size_total = size_vmode;

 	/*   size_remap -- the amount of video memory we are going to
 	 *                 use for efifb.  With modern cards it is no
 	 *                 option to simply use size_total as that
 	 *                 wastes plenty of kernel address space. */
 	size_remap  = size_vmode * 2;
 	if (size_remap > size_total)
 		size_remap = size_total;
 	if (size_remap % PAGE_SIZE)
 		size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
 	efifb_fix.smem_len = size_remap;

 	if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
 		request_mem_succeeded = true;
 	} else {
 		/* We cannot make this fatal. Sometimes this comes from magic
 		   spaces our resource handlers simply don't know about */
 		pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
 			efifb_fix.smem_start);
 	}

 	info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
 	if (!info) {
 		pr_err("efifb: cannot allocate framebuffer\n");
 		err = -ENOMEM;
 		goto err_release_mem;
 	}
 	platform_set_drvdata(dev, info);
 	info->pseudo_palette = info->par;
 	info->par = NULL;

 	info->apertures = alloc_apertures(1);
 	if (!info->apertures) {
 		err = -ENOMEM;
 		goto err_release_fb;
 	}
 	info->apertures->ranges[0].base = efifb_fix.smem_start;
 	info->apertures->ranges[0].size = size_remap;

 	if (nowc)
 		info->screen_base = ioremap(efifb_fix.smem_start, efifb_fix.smem_len);
 	else
 		info->screen_base = ioremap_wc(efifb_fix.smem_start, efifb_fix.smem_len);
 	if (!info->screen_base) {
 		pr_err("efifb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
 			efifb_fix.smem_len, efifb_fix.smem_start);
 		err = -EIO;
 		goto err_release_fb;
 	}

 	pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
 	       efifb_fix.smem_start, size_remap/1024, size_total/1024);
 	pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
 	       efifb_defined.xres, efifb_defined.yres,
 	       efifb_defined.bits_per_pixel, efifb_fix.line_length,
 	       screen_info.pages);

 	efifb_defined.xres_virtual = efifb_defined.xres;
 	efifb_defined.yres_virtual = efifb_fix.smem_len /
 					efifb_fix.line_length;
 	pr_info("efifb: scrolling: redraw\n");
 	efifb_defined.yres_virtual = efifb_defined.yres;

 	/* some dummy values for timing to make fbset happy */
 	efifb_defined.pixclock     = 10000000 / efifb_defined.xres *
 					1000 / efifb_defined.yres;
 	efifb_defined.left_margin  = (efifb_defined.xres / 8) & 0xf8;
 	efifb_defined.hsync_len    = (efifb_defined.xres / 8) & 0xf8;

 	efifb_defined.red.offset    = screen_info.red_pos;
 	efifb_defined.red.length    = screen_info.red_size;
 	efifb_defined.green.offset  = screen_info.green_pos;
 	efifb_defined.green.length  = screen_info.green_size;
 	efifb_defined.blue.offset   = screen_info.blue_pos;
 	efifb_defined.blue.length   = screen_info.blue_size;
 	efifb_defined.transp.offset = screen_info.rsvd_pos;
 	efifb_defined.transp.length = screen_info.rsvd_size;

 	pr_info("efifb: %s: "
 	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
 	       "Truecolor",
 	       screen_info.rsvd_size,
 	       screen_info.red_size,
 	       screen_info.green_size,
 	       screen_info.blue_size,
 	       screen_info.rsvd_pos,
 	       screen_info.red_pos,
 	       screen_info.green_pos,
 	       screen_info.blue_pos);

 	efifb_fix.ypanstep  = 0;
 	efifb_fix.ywrapstep = 0;

 	info->fbops = &efifb_ops;
 	info->var = efifb_defined;
 	info->fix = efifb_fix;
 	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;

 	orientation = drm_get_panel_orientation_quirk(efifb_defined.xres,
 						      efifb_defined.yres);
 	switch (orientation) {
 	default:
 		info->fbcon_rotate_hint = FB_ROTATE_UR;
 		break;
 	case DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP:
 		info->fbcon_rotate_hint = FB_ROTATE_UD;
 		break;
 	case DRM_MODE_PANEL_ORIENTATION_LEFT_UP:
 		info->fbcon_rotate_hint = FB_ROTATE_CCW;
 		break;
 	case DRM_MODE_PANEL_ORIENTATION_RIGHT_UP:
 		info->fbcon_rotate_hint = FB_ROTATE_CW;
 		break;
 	}

 	err = sysfs_create_groups(&dev->dev.kobj, efifb_groups);
 	if (err) {
 		pr_err("efifb: cannot add sysfs attrs\n");
 		goto err_unmap;
 	}
 	err = fb_alloc_cmap(&info->cmap, 256, 0);
 	if (err < 0) {
 		pr_err("efifb: cannot allocate colormap\n");
 		goto err_groups;
 	}
 	err = register_framebuffer(info);
 	if (err < 0) {
 		pr_err("efifb: cannot register framebuffer\n");
 		goto err_fb_dealoc;
 	}
 	fb_info(info, "%s frame buffer device\n", info->fix.id);
 	return 0;

 err_fb_dealoc:
 	fb_dealloc_cmap(&info->cmap);
 err_groups:
 	sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
 err_unmap:
 	iounmap(info->screen_base);
 err_release_fb:
 	framebuffer_release(info);
 err_release_mem:
 	if (request_mem_succeeded)
 		release_mem_region(efifb_fix.smem_start, size_total);
 	return err;
 }

 static int efifb_remove(struct platform_device *pdev)
 {
 	struct fb_info *info = platform_get_drvdata(pdev);

 	unregister_framebuffer(info);
 	sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
 	framebuffer_release(info);

 	return 0;
 }

 static struct platform_driver efifb_driver = {
 	.driver = {
 		.name = "efi-framebuffer",
 	},
 	.probe = efifb_probe,
 	.remove = efifb_remove,
 };

 builtin_platform_driver(efifb_driver);

 #if defined(CONFIG_PCI)

 static void record_efifb_bar_resource(struct pci_dev *dev, int idx, u64 offset)
 {
 	u16 word;

 	efifb_pci_dev = dev;

 	pci_read_config_word(dev, PCI_COMMAND, &word);
 	if (!(word & PCI_COMMAND_MEMORY)) {
 		pci_dev_disabled = true;
 		dev_err(&dev->dev,
 			"BAR %d: assigned to efifb but device is disabled!\n",
 			idx);
 		return;
 	}

 	bar_resource = &dev->resource[idx];
 	bar_offset = offset;

 	dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
 }

 static void efifb_fixup_resources(struct pci_dev *dev)
 {
 	u64 base = screen_info.lfb_base;
 	u64 size = screen_info.lfb_size;
 	int i;

 	if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
 		return;

 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
 		base |= (u64)screen_info.ext_lfb_base << 32;

 	if (!base)
 		return;

 	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
 		struct resource *res = &dev->resource[i];

 		if (!(res->flags & IORESOURCE_MEM))
 			continue;

 		if (res->start <= base && res->end >= base + size - 1) {
 			record_efifb_bar_resource(dev, i, base - res->start);
 			break;
 		}
 	}
 }
 DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY,
 			       16, efifb_fixup_resources);

 #endif
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Framebuffer driver for EFI/UEFI based system
	*
	* (c) 2006 Edgar Hucek <gimli@dark-green.com>
	* Original efi driver written by Gerd Knorr <kraxel@goldbach.in-berlin.de>
	*
	*/

	#include <linux/kernel.h>
	#include <linux/efi.h>
	#include <linux/errno.h>
	#include <linux/fb.h>
	#include <linux/pci.h>
	#include <linux/platform_device.h>
	#include <linux/screen_info.h>
	#include <video/vga.h>
	#include <asm/efi.h>
	#include <drm/drm_utils.h> /* For drm_get_panel_orientation_quirk */
	#include <drm/drm_connector.h> /* For DRM_MODE_PANEL_ORIENTATION_* */

	static bool request_mem_succeeded = false;
	static bool nowc = false;

	static struct fb_var_screeninfo efifb_defined = {
	.activate = FB_ACTIVATE_NOW,
	.height = -1,
	.width = -1,
	.right_margin = 32,
	.upper_margin = 16,
	.lower_margin = 4,
	.vsync_len = 4,
	.vmode = FB_VMODE_NONINTERLACED,
	};

	static struct fb_fix_screeninfo efifb_fix = {
	.id = "EFI VGA",
	.type = FB_TYPE_PACKED_PIXELS,
	.accel = FB_ACCEL_NONE,
	.visual = FB_VISUAL_TRUECOLOR,
	};

	static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
	unsigned blue, unsigned transp,
	struct fb_info *info)
	{
	/*
	* Set a single color register. The values supplied are
	* already rounded down to the hardware's capabilities
	* (according to the entries in the `var' structure). Return
	* != 0 for invalid regno.
	*/

	if (regno >= info->cmap.len)
	return 1;

	if (regno < 16) {
	red >>= 16 - info->var.red.length;
	green >>= 16 - info->var.green.length;
	blue >>= 16 - info->var.blue.length;
	((u32 *)(info->pseudo_palette))[regno] =
	(red << info->var.red.offset) \|
	(green << info->var.green.offset) \|
	(blue << info->var.blue.offset);
	}
	return 0;
	}

	static void efifb_destroy(struct fb_info *info)
	{
	if (info->screen_base)
	iounmap(info->screen_base);
	if (request_mem_succeeded)
	release_mem_region(info->apertures->ranges[0].base,
	info->apertures->ranges[0].size);
	fb_dealloc_cmap(&info->cmap);
	}

	static struct fb_ops efifb_ops = {
	.owner = THIS_MODULE,
	.fb_destroy = efifb_destroy,
	.fb_setcolreg = efifb_setcolreg,
	.fb_fillrect = cfb_fillrect,
	.fb_copyarea = cfb_copyarea,
	.fb_imageblit = cfb_imageblit,
	};

	static int efifb_setup(char *options)
	{
	char *this_opt;

	if (options && *options) {
	while ((this_opt = strsep(&options, ",")) != NULL) {
	if (!*this_opt) continue;

	efifb_setup_from_dmi(&screen_info, this_opt);

	if (!strncmp(this_opt, "base:", 5))
	screen_info.lfb_base = simple_strtoul(this_opt+5, NULL, 0);
	else if (!strncmp(this_opt, "stride:", 7))
	screen_info.lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
	else if (!strncmp(this_opt, "height:", 7))
	screen_info.lfb_height = simple_strtoul(this_opt+7, NULL, 0);
	else if (!strncmp(this_opt, "width:", 6))
	screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);
	else if (!strcmp(this_opt, "nowc"))
	nowc = true;
	}
	}

	return 0;
	}

	static inline bool fb_base_is_valid(void)
	{
	if (screen_info.lfb_base)
	return true;

	if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
	return false;

	if (screen_info.ext_lfb_base)
	return true;

	return false;
	}

	#define efifb_attr_decl(name, fmt) \
	static ssize_t name##_show(struct device *dev, \
	struct device_attribute *attr, \
	char *buf) \
	{ \
	return sprintf(buf, fmt "\n", (screen_info.lfb_##name)); \
	} \
	static DEVICE_ATTR_RO(name)

	efifb_attr_decl(base, "0x%x");
	efifb_attr_decl(linelength, "%u");
	efifb_attr_decl(height, "%u");
	efifb_attr_decl(width, "%u");
	efifb_attr_decl(depth, "%u");

	static struct attribute *efifb_attrs[] = {
	&dev_attr_base.attr,
	&dev_attr_linelength.attr,
	&dev_attr_width.attr,
	&dev_attr_height.attr,
	&dev_attr_depth.attr,
	NULL
	};
	ATTRIBUTE_GROUPS(efifb);

	static bool pci_dev_disabled; /* FB base matches BAR of a disabled device */

	static struct pci_dev efifb_pci_dev; / dev with BAR covering the efifb */
	static struct resource *bar_resource;
	static u64 bar_offset;

	static int efifb_probe(struct platform_device *dev)
	{
	struct fb_info *info;
	int err, orientation;
	unsigned int size_vmode;
	unsigned int size_remap;
	unsigned int size_total;
	char *option = NULL;

	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI \|\| pci_dev_disabled)
	return -ENODEV;

	if (fb_get_options("efifb", &option))
	return -ENODEV;
	efifb_setup(option);

	/* We don't get linelength from UGA Draw Protocol, only from
	* EFI Graphics Protocol. So if it's not in DMI, and it's not
	* passed in from the user, we really can't use the framebuffer.
	*/
	if (!screen_info.lfb_linelength)
	return -ENODEV;

	if (!screen_info.lfb_depth)
	screen_info.lfb_depth = 32;
	if (!screen_info.pages)
	screen_info.pages = 1;
	if (!fb_base_is_valid()) {
	printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
	return -ENODEV;
	}
	printk(KERN_INFO "efifb: probing for efifb\n");

	/* just assume they're all unset if any are */
	if (!screen_info.blue_size) {
	screen_info.blue_size = 8;
	screen_info.blue_pos = 0;
	screen_info.green_size = 8;
	screen_info.green_pos = 8;
	screen_info.red_size = 8;
	screen_info.red_pos = 16;
	screen_info.rsvd_size = 8;
	screen_info.rsvd_pos = 24;
	}

	efifb_fix.smem_start = screen_info.lfb_base;

	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
	u64 ext_lfb_base;

	ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
	efifb_fix.smem_start \|= ext_lfb_base;
	}

	if (bar_resource &&
	bar_resource->start + bar_offset != efifb_fix.smem_start) {
	dev_info(&efifb_pci_dev->dev,
	"BAR has moved, updating efifb address\n");
	efifb_fix.smem_start = bar_resource->start + bar_offset;
	}

	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
	efifb_defined.xres = screen_info.lfb_width;
	efifb_defined.yres = screen_info.lfb_height;
	efifb_fix.line_length = screen_info.lfb_linelength;

	/* size_vmode -- that is the amount of memory needed for the
	* used video mode, i.e. the minimum amount of
	* memory we need. */
	size_vmode = efifb_defined.yres * efifb_fix.line_length;

	/* size_total -- all video memory we have. Used for
	* entries, ressource allocation and bounds
	* checking. */
	size_total = screen_info.lfb_size;
	if (size_total < size_vmode)
	size_total = size_vmode;

	/* size_remap -- the amount of video memory we are going to
	* use for efifb. With modern cards it is no
	* option to simply use size_total as that
	* wastes plenty of kernel address space. */
	size_remap = size_vmode * 2;
	if (size_remap > size_total)
	size_remap = size_total;
	if (size_remap % PAGE_SIZE)
	size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
	efifb_fix.smem_len = size_remap;

	if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
	request_mem_succeeded = true;
	} else {
	/* We cannot make this fatal. Sometimes this comes from magic
	spaces our resource handlers simply don't know about */
	pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
	efifb_fix.smem_start);
	}

	info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
	if (!info) {
	pr_err("efifb: cannot allocate framebuffer\n");
	err = -ENOMEM;
	goto err_release_mem;
	}
	platform_set_drvdata(dev, info);
	info->pseudo_palette = info->par;
	info->par = NULL;

	info->apertures = alloc_apertures(1);
	if (!info->apertures) {
	err = -ENOMEM;
	goto err_release_fb;
	}
	info->apertures->ranges[0].base = efifb_fix.smem_start;
	info->apertures->ranges[0].size = size_remap;

	if (nowc)
	info->screen_base = ioremap(efifb_fix.smem_start, efifb_fix.smem_len);
	else
	info->screen_base = ioremap_wc(efifb_fix.smem_start, efifb_fix.smem_len);
	if (!info->screen_base) {
	pr_err("efifb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
	efifb_fix.smem_len, efifb_fix.smem_start);
	err = -EIO;
	goto err_release_fb;
	}

	pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
	efifb_fix.smem_start, size_remap/1024, size_total/1024);
	pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
	efifb_defined.xres, efifb_defined.yres,
	efifb_defined.bits_per_pixel, efifb_fix.line_length,
	screen_info.pages);

	efifb_defined.xres_virtual = efifb_defined.xres;
	efifb_defined.yres_virtual = efifb_fix.smem_len /
	efifb_fix.line_length;
	pr_info("efifb: scrolling: redraw\n");
	efifb_defined.yres_virtual = efifb_defined.yres;

	/* some dummy values for timing to make fbset happy */
	efifb_defined.pixclock = 10000000 / efifb_defined.xres *
	1000 / efifb_defined.yres;
	efifb_defined.left_margin = (efifb_defined.xres / 8) & 0xf8;
	efifb_defined.hsync_len = (efifb_defined.xres / 8) & 0xf8;

	efifb_defined.red.offset = screen_info.red_pos;
	efifb_defined.red.length = screen_info.red_size;
	efifb_defined.green.offset = screen_info.green_pos;
	efifb_defined.green.length = screen_info.green_size;
	efifb_defined.blue.offset = screen_info.blue_pos;
	efifb_defined.blue.length = screen_info.blue_size;
	efifb_defined.transp.offset = screen_info.rsvd_pos;
	efifb_defined.transp.length = screen_info.rsvd_size;

	pr_info("efifb: %s: "
	"size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
	"Truecolor",
	screen_info.rsvd_size,
	screen_info.red_size,
	screen_info.green_size,
	screen_info.blue_size,
	screen_info.rsvd_pos,
	screen_info.red_pos,
	screen_info.green_pos,
	screen_info.blue_pos);

	efifb_fix.ypanstep = 0;
	efifb_fix.ywrapstep = 0;

	info->fbops = &efifb_ops;
	info->var = efifb_defined;
	info->fix = efifb_fix;
	info->flags = FBINFO_FLAG_DEFAULT \| FBINFO_MISC_FIRMWARE;

	orientation = drm_get_panel_orientation_quirk(efifb_defined.xres,
	efifb_defined.yres);
	switch (orientation) {
	default:
	info->fbcon_rotate_hint = FB_ROTATE_UR;
	break;
	case DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP:
	info->fbcon_rotate_hint = FB_ROTATE_UD;
	break;
	case DRM_MODE_PANEL_ORIENTATION_LEFT_UP:
	info->fbcon_rotate_hint = FB_ROTATE_CCW;
	break;
	case DRM_MODE_PANEL_ORIENTATION_RIGHT_UP:
	info->fbcon_rotate_hint = FB_ROTATE_CW;
	break;
	}

	err = sysfs_create_groups(&dev->dev.kobj, efifb_groups);
	if (err) {
	pr_err("efifb: cannot add sysfs attrs\n");
	goto err_unmap;
	}
	err = fb_alloc_cmap(&info->cmap, 256, 0);
	if (err < 0) {
	pr_err("efifb: cannot allocate colormap\n");
	goto err_groups;
	}
	err = register_framebuffer(info);
	if (err < 0) {
	pr_err("efifb: cannot register framebuffer\n");
	goto err_fb_dealoc;
	}
	fb_info(info, "%s frame buffer device\n", info->fix.id);
	return 0;

	err_fb_dealoc:
	fb_dealloc_cmap(&info->cmap);
	err_groups:
	sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
	err_unmap:
	iounmap(info->screen_base);
	err_release_fb:
	framebuffer_release(info);
	err_release_mem:
	if (request_mem_succeeded)
	release_mem_region(efifb_fix.smem_start, size_total);
	return err;
	}

	static int efifb_remove(struct platform_device *pdev)
	{
	struct fb_info *info = platform_get_drvdata(pdev);

	unregister_framebuffer(info);
	sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
	framebuffer_release(info);

	return 0;
	}

	static struct platform_driver efifb_driver = {
	.driver = {
	.name = "efi-framebuffer",
	},
	.probe = efifb_probe,
	.remove = efifb_remove,
	};

	builtin_platform_driver(efifb_driver);

	#if defined(CONFIG_PCI)

	static void record_efifb_bar_resource(struct pci_dev *dev, int idx, u64 offset)
	{
	u16 word;

	efifb_pci_dev = dev;

	pci_read_config_word(dev, PCI_COMMAND, &word);
	if (!(word & PCI_COMMAND_MEMORY)) {
	pci_dev_disabled = true;
	dev_err(&dev->dev,
	"BAR %d: assigned to efifb but device is disabled!\n",
	idx);
	return;
	}

	bar_resource = &dev->resource[idx];
	bar_offset = offset;

	dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
	}

	static void efifb_fixup_resources(struct pci_dev *dev)
	{
	u64 base = screen_info.lfb_base;
	u64 size = screen_info.lfb_size;
	int i;

	if (efifb_pci_dev \|\| screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
	return;

	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
	base \|= (u64)screen_info.ext_lfb_base << 32;

	if (!base)
	return;

	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
	struct resource *res = &dev->resource[i];

	if (!(res->flags & IORESOURCE_MEM))
	continue;

	if (res->start <= base && res->end >= base + size - 1) {
	record_efifb_bar_resource(dev, i, base - res->start);
	break;
	}
	}
	}
	DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY,
	16, efifb_fixup_resources);

	#endif