text: /*
   *  linux/drivers/video/fbmem.c
   *
   *  Copyright (C) 1994 Martin Schaller
   *
   *	2001 - Documented with DocBook
   *	- Brad Douglas <brad@neruo.com>
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file COPYING in the main directory of this archive
   * for more details.
   */
  
  #include <linux/module.h>
  
  #include <linux/compat.h>
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/kernel.h>
  #include <linux/major.h>
  #include <linux/slab.h>
  #include <linux/mm.h>
  #include <linux/mman.h>
  #include <linux/vt.h>
  #include <linux/init.h>
  #include <linux/linux_logo.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>
  #include <linux/console.h>
  #include <linux/kmod.h>
  #include <linux/err.h>
  #include <linux/device.h>
  #include <linux/efi.h>
  #include <linux/fb.h>
  #include <linux/fbcon.h>
  #include <linux/mem_encrypt.h>
  #include <linux/pci.h>
  
  #include <asm/fb.h>
  
  
      /*
       *  Frame buffer device initialization and setup routines
       */
  
  #define FBPIXMAPSIZE	(1024 * 8)
  
  static DEFINE_MUTEX(registration_lock);
  
  struct fb_info *registered_fb[FB_MAX] __read_mostly;
  EXPORT_SYMBOL(registered_fb);
  
  int num_registered_fb __read_mostly;
  EXPORT_SYMBOL(num_registered_fb);
  
  bool fb_center_logo __read_mostly;
  EXPORT_SYMBOL(fb_center_logo);
  
  static struct fb_info *get_fb_info(unsigned int idx)
  {
  	struct fb_info *fb_info;
  
  	if (idx >= FB_MAX)
  		return ERR_PTR(-ENODEV);
  
  	mutex_lock(&registration_lock);
  	fb_info = registered_fb[idx];
  	if (fb_info)
  		atomic_inc(&fb_info->count);
  	mutex_unlock(&registration_lock);
  
  	return fb_info;
  }
  
  static void put_fb_info(struct fb_info *fb_info)
  {
  	if (!atomic_dec_and_test(&fb_info->count))
  		return;
  	if (fb_info->fbops->fb_destroy)
  		fb_info->fbops->fb_destroy(fb_info);
  }
  
  int lock_fb_info(struct fb_info *info)
  {
  	mutex_lock(&info->lock);
  	if (!info->fbops) {
  		mutex_unlock(&info->lock);
  		return 0;
  	}
  	return 1;
  }
  EXPORT_SYMBOL(lock_fb_info);
  
  /*
   * Helpers
   */
  
  int fb_get_color_depth(struct fb_var_screeninfo *var,
  		       struct fb_fix_screeninfo *fix)
  {
  	int depth = 0;
  
  	if (fix->visual == FB_VISUAL_MONO01 ||
  	    fix->visual == FB_VISUAL_MONO10)
  		depth = 1;
  	else {
  		if (var->green.length == var->blue.length &&
  		    var->green.length == var->red.length &&
  		    var->green.offset == var->blue.offset &&
  		    var->green.offset == var->red.offset)
  			depth = var->green.length;
  		else
  			depth = var->green.length + var->red.length +
  				var->blue.length;
  	}
  
  	return depth;
  }
  EXPORT_SYMBOL(fb_get_color_depth);
  
  /*
   * Data padding functions.
   */
  void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 s_pitch, u32 height)
  {
  	__fb_pad_aligned_buffer(dst, d_pitch, src, s_pitch, height);
  }
  EXPORT_SYMBOL(fb_pad_aligned_buffer);
  
  void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 idx, u32 height,
  				u32 shift_high, u32 shift_low, u32 mod)
  {
  	u8 mask = (u8) (0xfff << shift_high), tmp;
  	int i, j;
  
  	for (i = height; i--; ) {
  		for (j = 0; j < idx; j++) {
  			tmp = dst[j];
  			tmp &= mask;
  			tmp |= *src >> shift_low;
  			dst[j] = tmp;
  			tmp = *src << shift_high;
  			dst[j+1] = tmp;
  			src++;
  		}
  		tmp = dst[idx];
  		tmp &= mask;
  		tmp |= *src >> shift_low;
  		dst[idx] = tmp;
  		if (shift_high < mod) {
  			tmp = *src << shift_high;
  			dst[idx+1] = tmp;
  		}
  		src++;
  		dst += d_pitch;
  	}
  }
  EXPORT_SYMBOL(fb_pad_unaligned_buffer);
  
  /*
   * we need to lock this section since fb_cursor
   * may use fb_imageblit()
   */
  char* fb_get_buffer_offset(struct fb_info *info, struct fb_pixmap *buf, u32 size)
  {
  	u32 align = buf->buf_align - 1, offset;
  	char *addr = buf->addr;
  
  	/* If IO mapped, we need to sync before access, no sharing of
  	 * the pixmap is done
  	 */
  	if (buf->flags & FB_PIXMAP_IO) {
  		if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
  			info->fbops->fb_sync(info);
  		return addr;
  	}
  
  	/* See if we fit in the remaining pixmap space */
  	offset = buf->offset + align;
  	offset &= ~align;
  	if (offset + size > buf->size) {
  		/* We do not fit. In order to be able to re-use the buffer,
  		 * we must ensure no asynchronous DMA'ing or whatever operation
  		 * is in progress, we sync for that.
  		 */
  		if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
  			info->fbops->fb_sync(info);
  		offset = 0;
  	}
  	buf->offset = offset + size;
  	addr += offset;
  
  	return addr;
  }
  EXPORT_SYMBOL(fb_get_buffer_offset);
  
  #ifdef CONFIG_LOGO
  
  static inline unsigned safe_shift(unsigned d, int n)
  {
  	return n < 0 ? d >> -n : d << n;
  }
  
  static void fb_set_logocmap(struct fb_info *info,
  				   const struct linux_logo *logo)
  {
  	struct fb_cmap palette_cmap;
  	u16 palette_green[16];
  	u16 palette_blue[16];
  	u16 palette_red[16];
  	int i, j, n;
  	const unsigned char *clut = logo->clut;
  
  	palette_cmap.start = 0;
  	palette_cmap.len = 16;
  	palette_cmap.red = palette_red;
  	palette_cmap.green = palette_green;
  	palette_cmap.blue = palette_blue;
  	palette_cmap.transp = NULL;
  
  	for (i = 0; i < logo->clutsize; i += n) {
  		n = logo->clutsize - i;
  		/* palette_cmap provides space for only 16 colors at once */
  		if (n > 16)
  			n = 16;
  		palette_cmap.start = 32 + i;
  		palette_cmap.len = n;
  		for (j = 0; j < n; ++j) {
  			palette_cmap.red[j] = clut[0] << 8 | clut[0];
  			palette_cmap.green[j] = clut[1] << 8 | clut[1];
  			palette_cmap.blue[j] = clut[2] << 8 | clut[2];
  			clut += 3;
  		}
  		fb_set_cmap(&palette_cmap, info);
  	}
  }
  
  static void  fb_set_logo_truepalette(struct fb_info *info,
  					    const struct linux_logo *logo,
  					    u32 *palette)
  {
  	static const unsigned char mask[] = { 0,0x80,0xc0,0xe0,0xf0,0xf8,0xfc,0xfe,0xff };
  	unsigned char redmask, greenmask, bluemask;
  	int redshift, greenshift, blueshift;
  	int i;
  	const unsigned char *clut = logo->clut;
  
  	/*
  	 * We have to create a temporary palette since console palette is only
  	 * 16 colors long.
  	 */
  	/* Bug: Doesn't obey msb_right ... (who needs that?) */
  	redmask   = mask[info->var.red.length   < 8 ? info->var.red.length   : 8];
  	greenmask = mask[info->var.green.length < 8 ? info->var.green.length : 8];
  	bluemask  = mask[info->var.blue.length  < 8 ? info->var.blue.length  : 8];
  	redshift   = info->var.red.offset   - (8 - info->var.red.length);
  	greenshift = info->var.green.offset - (8 - info->var.green.length);
  	blueshift  = info->var.blue.offset  - (8 - info->var.blue.length);
  
  	for ( i = 0; i < logo->clutsize; i++) {
  		palette[i+32] = (safe_shift((clut[0] & redmask), redshift) |
  				 safe_shift((clut[1] & greenmask), greenshift) |
  				 safe_shift((clut[2] & bluemask), blueshift));
  		clut += 3;
  	}
  }
  
  static void fb_set_logo_directpalette(struct fb_info *info,
  					     const struct linux_logo *logo,
  					     u32 *palette)
  {
  	int redshift, greenshift, blueshift;
  	int i;
  
  	redshift = info->var.red.offset;
  	greenshift = info->var.green.offset;
  	blueshift = info->var.blue.offset;
  
  	for (i = 32; i < 32 + logo->clutsize; i++)
  		palette[i] = i << redshift | i << greenshift | i << blueshift;
  }
  
  static void fb_set_logo(struct fb_info *info,
  			       const struct linux_logo *logo, u8 *dst,
  			       int depth)
  {
  	int i, j, k;
  	const u8 *src = logo->data;
  	u8 xor = (info->fix.visual == FB_VISUAL_MONO01) ? 0xff : 0;
  	u8 fg = 1, d;
  
  	switch (fb_get_color_depth(&info->var, &info->fix)) {
  	case 1:
  		fg = 1;
  		break;
  	case 2:
  		fg = 3;
  		break;
  	default:
  		fg = 7;
  		break;
  	}
  
  	if (info->fix.visual == FB_VISUAL_MONO01 ||
  	    info->fix.visual == FB_VISUAL_MONO10)
  		fg = ~((u8) (0xfff << info->var.green.length));
  
  	switch (depth) {
  	case 4:
  		for (i = 0; i < logo->height; i++)
  			for (j = 0; j < logo->width; src++) {
  				*dst++ = *src >> 4;
  				j++;
  				if (j < logo->width) {
  					*dst++ = *src & 0x0f;
  					j++;
  				}
  			}
  		break;
  	case 1:
  		for (i = 0; i < logo->height; i++) {
  			for (j = 0; j < logo->width; src++) {
  				d = *src ^ xor;
  				for (k = 7; k >= 0 && j < logo->width; k--) {
  					*dst++ = ((d >> k) & 1) ? fg : 0;
  					j++;
  				}
  			}
  		}
  		break;
  	}
  }
  
  /*
   * Three (3) kinds of logo maps exist.  linux_logo_clut224 (>16 colors),
   * linux_logo_vga16 (16 colors) and linux_logo_mono (2 colors).  Depending on
   * the visual format and color depth of the framebuffer, the DAC, the
   * pseudo_palette, and the logo data will be adjusted accordingly.
   *
   * Case 1 - linux_logo_clut224:
   * Color exceeds the number of console colors (16), thus we set the hardware DAC
   * using fb_set_cmap() appropriately.  The "needs_cmapreset"  flag will be set.
   *
   * For visuals that require color info from the pseudo_palette, we also construct
   * one for temporary use. The "needs_directpalette" or "needs_truepalette" flags
   * will be set.
   *
   * Case 2 - linux_logo_vga16:
   * The number of colors just matches the console colors, thus there is no need
   * to set the DAC or the pseudo_palette.  However, the bitmap is packed, ie,
   * each byte contains color information for two pixels (upper and lower nibble).
   * To be consistent with fb_imageblit() usage, we therefore separate the two
   * nibbles into separate bytes. The "depth" flag will be set to 4.
   *
   * Case 3 - linux_logo_mono:
   * This is similar with Case 2.  Each byte contains information for 8 pixels.
   * We isolate each bit and expand each into a byte. The "depth" flag will
   * be set to 1.
   */
  static struct logo_data {
  	int depth;
  	int needs_directpalette;
  	int needs_truepalette;
  	int needs_cmapreset;
  	const struct linux_logo *logo;
  } fb_logo __read_mostly;
  
  static void fb_rotate_logo_ud(const u8 *in, u8 *out, u32 width, u32 height)
  {
  	u32 size = width * height, i;
  
  	out += size - 1;
  
  	for (i = size; i--; )
  		*out-- = *in++;
  }
  
  static void fb_rotate_logo_cw(const u8 *in, u8 *out, u32 width, u32 height)
  {
  	int i, j, h = height - 1;
  
  	for (i = 0; i < height; i++)
  		for (j = 0; j < width; j++)
  				out[height * j + h - i] = *in++;
  }
  
  static void fb_rotate_logo_ccw(const u8 *in, u8 *out, u32 width, u32 height)
  {
  	int i, j, w = width - 1;
  
  	for (i = 0; i < height; i++)
  		for (j = 0; j < width; j++)
  			out[height * (w - j) + i] = *in++;
  }
  
  static void fb_rotate_logo(struct fb_info *info, u8 *dst,
  			   struct fb_image *image, int rotate)
  {
  	u32 tmp;
  
  	if (rotate == FB_ROTATE_UD) {
  		fb_rotate_logo_ud(image->data, dst, image->width,
  				  image->height);
  		image->dx = info->var.xres - image->width - image->dx;
  		image->dy = info->var.yres - image->height - image->dy;
  	} else if (rotate == FB_ROTATE_CW) {
  		fb_rotate_logo_cw(image->data, dst, image->width,
  				  image->height);
  		tmp = image->width;
  		image->width = image->height;
  		image->height = tmp;
  		tmp = image->dy;
  		image->dy = image->dx;
  		image->dx = info->var.xres - image->width - tmp;
  	} else if (rotate == FB_ROTATE_CCW) {
  		fb_rotate_logo_ccw(image->data, dst, image->width,
  				   image->height);
  		tmp = image->width;
  		image->width = image->height;
  		image->height = tmp;
  		tmp = image->dx;
  		image->dx = image->dy;
  		image->dy = info->var.yres - image->height - tmp;
  	}
  
  	image->data = dst;
  }
  
  static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
  			    int rotate, unsigned int num)
  {
  	unsigned int x;
  
  	if (image->width > info->var.xres || image->height > info->var.yres)
  		return;
  
  	if (rotate == FB_ROTATE_UR) {
  		for (x = 0;
  		     x < num && image->dx + image->width <= info->var.xres;
  		     x++) {
  			info->fbops->fb_imageblit(info, image);
  			image->dx += image->width + 8;
  		}
  	} else if (rotate == FB_ROTATE_UD) {
  		u32 dx = image->dx;
  
  		for (x = 0; x < num && image->dx <= dx; x++) {
  			info->fbops->fb_imageblit(info, image);
  			image->dx -= image->width + 8;
  		}
  	} else if (rotate == FB_ROTATE_CW) {
  		for (x = 0;
  		     x < num && image->dy + image->height <= info->var.yres;
  		     x++) {
  			info->fbops->fb_imageblit(info, image);
  			image->dy += image->height + 8;
  		}
  	} else if (rotate == FB_ROTATE_CCW) {
  		u32 dy = image->dy;
  
  		for (x = 0; x < num && image->dy <= dy; x++) {
  			info->fbops->fb_imageblit(info, image);
  			image->dy -= image->height + 8;
  		}
  	}
  }
  
  static int fb_show_logo_line(struct fb_info *info, int rotate,
  			     const struct linux_logo *logo, int y,
  			     unsigned int n)
  {
  	u32 *palette = NULL, *saved_pseudo_palette = NULL;
  	unsigned char *logo_new = NULL, *logo_rotate = NULL;
  	struct fb_image image;
  
  	/* Return if the frame buffer is not mapped or suspended */
  	if (logo == NULL || info->state != FBINFO_STATE_RUNNING ||
  	    info->fbops->owner)
  		return 0;
  
  	image.depth = 8;
  	image.data = logo->data;
  
  	if (fb_logo.needs_cmapreset)
  		fb_set_logocmap(info, logo);
  
  	if (fb_logo.needs_truepalette ||
  	    fb_logo.needs_directpalette) {
  		palette = kmalloc(256 * 4, GFP_KERNEL);
  		if (palette == NULL)
  			return 0;
  
  		if (fb_logo.needs_truepalette)
  			fb_set_logo_truepalette(info, logo, palette);
  		else
  			fb_set_logo_directpalette(info, logo, palette);
  
  		saved_pseudo_palette = info->pseudo_palette;
  		info->pseudo_palette = palette;
  	}
  
  	if (fb_logo.depth <= 4) {
  		logo_new = kmalloc_array(logo->width, logo->height,
  					 GFP_KERNEL);
  		if (logo_new == NULL) {
  			kfree(palette);
  			if (saved_pseudo_palette)
  				info->pseudo_palette = saved_pseudo_palette;
  			return 0;
  		}
  		image.data = logo_new;
  		fb_set_logo(info, logo, logo_new, fb_logo.depth);
  	}
  
  	if (fb_center_logo) {
  		int xres = info->var.xres;
  		int yres = info->var.yres;
  
  		if (rotate == FB_ROTATE_CW || rotate == FB_ROTATE_CCW) {
  			xres = info->var.yres;
  			yres = info->var.xres;
  		}
  
  		while (n && (n * (logo->width + 8) - 8 > xres))
  			--n;
  		image.dx = (xres - n * (logo->width + 8) - 8) / 2;
  		image.dy = y ?: (yres - logo->height) / 2;
  	} else {
  		image.dx = 0;
  		image.dy = y;
  	}
  
  	image.width = logo->width;
  	image.height = logo->height;
  
  	if (rotate) {
  		logo_rotate = kmalloc_array(logo->width, logo->height,
  					    GFP_KERNEL);
  		if (logo_rotate)
  			fb_rotate_logo(info, logo_rotate, &image, rotate);
  	}
  
  	fb_do_show_logo(info, &image, rotate, n);
  
  	kfree(palette);
  	if (saved_pseudo_palette != NULL)
  		info->pseudo_palette = saved_pseudo_palette;
  	kfree(logo_new);
  	kfree(logo_rotate);
  	return image.dy + logo->height;
  }
  
  
  #ifdef CONFIG_FB_LOGO_EXTRA
  
  #define FB_LOGO_EX_NUM_MAX 10
  static struct logo_data_extra {
  	const struct linux_logo *logo;
  	unsigned int n;
  } fb_logo_ex[FB_LOGO_EX_NUM_MAX];
  static unsigned int fb_logo_ex_num;
  
  void fb_append_extra_logo(const struct linux_logo *logo, unsigned int n)
  {
  	if (!n || fb_logo_ex_num == FB_LOGO_EX_NUM_MAX)
  		return;
  
  	fb_logo_ex[fb_logo_ex_num].logo = logo;
  	fb_logo_ex[fb_logo_ex_num].n = n;
  	fb_logo_ex_num++;
  }
  
  static int fb_prepare_extra_logos(struct fb_info *info, unsigned int height,
  				  unsigned int yres)
  {
  	unsigned int i;
  
  	/* FIXME: logo_ex supports only truecolor fb. */
  	if (info->fix.visual != FB_VISUAL_TRUECOLOR)
  		fb_logo_ex_num = 0;
  
  	for (i = 0; i < fb_logo_ex_num; i++) {
  		if (fb_logo_ex[i].logo->type != fb_logo.logo->type) {
  			fb_logo_ex[i].logo = NULL;
  			continue;
  		}
  		height += fb_logo_ex[i].logo->height;
  		if (height > yres) {
  			height -= fb_logo_ex[i].logo->height;
  			fb_logo_ex_num = i;
  			break;
  		}
  	}
  	return height;
  }
  
  static int fb_show_extra_logos(struct fb_info *info, int y, int rotate)
  {
  	unsigned int i;
  
  	for (i = 0; i < fb_logo_ex_num; i++)
  		y = fb_show_logo_line(info, rotate,
  				      fb_logo_ex[i].logo, y, fb_logo_ex[i].n);
  
  	return y;
  }
  
  #else /* !CONFIG_FB_LOGO_EXTRA */
  
  static inline int fb_prepare_extra_logos(struct fb_info *info,
  					 unsigned int height,
  					 unsigned int yres)
  {
  	return height;
  }
  
  static inline int fb_show_extra_logos(struct fb_info *info, int y, int rotate)
  {
  	return y;
  }
  
  #endif /* CONFIG_FB_LOGO_EXTRA */
  
  
  int fb_prepare_logo(struct fb_info *info, int rotate)
  {
  	int depth = fb_get_color_depth(&info->var, &info->fix);
  	unsigned int yres;
  	int height;
  
  	memset(&fb_logo, 0, sizeof(struct logo_data));
  
  	if (info->flags & FBINFO_MISC_TILEBLITTING ||
  	    info->fbops->owner)
  		return 0;
  
  	if (info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
  		depth = info->var.blue.length;
  		if (info->var.red.length < depth)
  			depth = info->var.red.length;
  		if (info->var.green.length < depth)
  			depth = info->var.green.length;
  	}
  
  	if (info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR && depth > 4) {
  		/* assume console colormap */
  		depth = 4;
  	}
  
  	/* Return if no suitable logo was found */
  	fb_logo.logo = fb_find_logo(depth);
  
  	if (!fb_logo.logo) {
  		return 0;
  	}
  
  	if (rotate == FB_ROTATE_UR || rotate == FB_ROTATE_UD)
  		yres = info->var.yres;
  	else
  		yres = info->var.xres;
  
  	if (fb_logo.logo->height > yres) {
  		fb_logo.logo = NULL;
  		return 0;
  	}
  
  	/* What depth we asked for might be different from what we get */
  	if (fb_logo.logo->type == LINUX_LOGO_CLUT224)
  		fb_logo.depth = 8;
  	else if (fb_logo.logo->type == LINUX_LOGO_VGA16)
  		fb_logo.depth = 4;
  	else
  		fb_logo.depth = 1;
  
  
   	if (fb_logo.depth > 4 && depth > 4) {
   		switch (info->fix.visual) {
   		case FB_VISUAL_TRUECOLOR:
   			fb_logo.needs_truepalette = 1;
   			break;
   		case FB_VISUAL_DIRECTCOLOR:
   			fb_logo.needs_directpalette = 1;
   			fb_logo.needs_cmapreset = 1;
   			break;
   		case FB_VISUAL_PSEUDOCOLOR:
   			fb_logo.needs_cmapreset = 1;
   			break;
   		}
   	}
  
  	height = fb_logo.logo->height;
  	if (fb_center_logo)
  		height += (yres - fb_logo.logo->height) / 2;
  
  	return fb_prepare_extra_logos(info, height, yres);
  }
  
  int fb_show_logo(struct fb_info *info, int rotate)
  {
  	int y;
  
  	y = fb_show_logo_line(info, rotate, fb_logo.logo, 0,
  			      num_online_cpus());
  	y = fb_show_extra_logos(info, y, rotate);
  
  	return y;
  }
  #else
  int fb_prepare_logo(struct fb_info *info, int rotate) { return 0; }
  int fb_show_logo(struct fb_info *info, int rotate) { return 0; }
  #endif /* CONFIG_LOGO */
  EXPORT_SYMBOL(fb_prepare_logo);
  EXPORT_SYMBOL(fb_show_logo);
  
  static void *fb_seq_start(struct seq_file *m, loff_t *pos)
  {
  	mutex_lock(&registration_lock);
  	return (*pos < FB_MAX) ? pos : NULL;
  }
  
  static void *fb_seq_next(struct seq_file *m, void *v, loff_t *pos)
  {
  	(*pos)++;
  	return (*pos < FB_MAX) ? pos : NULL;
  }
  
  static void fb_seq_stop(struct seq_file *m, void *v)
  {
  	mutex_unlock(&registration_lock);
  }
  
  static int fb_seq_show(struct seq_file *m, void *v)
  {
  	int i = *(loff_t *)v;
  	struct fb_info *fi = registered_fb[i];
  
  	if (fi)
  		seq_printf(m, "%d %s\n", fi->node, fi->fix.id);
  	return 0;
  }
  
  static const struct seq_operations proc_fb_seq_ops = {
  	.start	= fb_seq_start,
  	.next	= fb_seq_next,
  	.stop	= fb_seq_stop,
  	.show	= fb_seq_show,
  };
  
  /*
   * We hold a reference to the fb_info in file->private_data,
   * but if the current registered fb has changed, we don't
   * actually want to use it.
   *
   * So look up the fb_info using the inode minor number,
   * and just verify it against the reference we have.
   */
  static struct fb_info *file_fb_info(struct file *file)
  {
  	struct inode *inode = file_inode(file);
  	int fbidx = iminor(inode);
  	struct fb_info *info = registered_fb[fbidx];
  
  	if (info != file->private_data)
  		info = NULL;
  	return info;
  }
  
  static ssize_t
  fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
  {
  	unsigned long p = *ppos;
  	struct fb_info *info = file_fb_info(file);
  	u8 *buffer, *dst;
  	u8 __iomem *src;
  	int c, cnt = 0, err = 0;
  	unsigned long total_size;
  
  	if (!info || ! info->screen_base)
  		return -ENODEV;
  
  	if (info->state != FBINFO_STATE_RUNNING)
  		return -EPERM;
  
  	if (info->fbops->fb_read)
  		return info->fbops->fb_read(info, buf, count, ppos);
  	
  	total_size = info->screen_size;
  
  	if (total_size == 0)
  		total_size = info->fix.smem_len;
  
  	if (p >= total_size)
  		return 0;
  
  	if (count >= total_size)
  		count = total_size;
  
  	if (count + p > total_size)
  		count = total_size - p;
  
  	buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count,
  			 GFP_KERNEL);
  	if (!buffer)
  		return -ENOMEM;
  
  	src = (u8 __iomem *) (info->screen_base + p);
  
  	if (info->fbops->fb_sync)
  		info->fbops->fb_sync(info);
  
  	while (count) {
  		c  = (count > PAGE_SIZE) ? PAGE_SIZE : count;
  		dst = buffer;
  		fb_memcpy_fromfb(dst, src, c);
  		dst += c;
  		src += c;
  
  		if (copy_to_user(buf, buffer, c)) {
  			err = -EFAULT;
  			break;
  		}
  		*ppos += c;
  		buf += c;
  		cnt += c;
  		count -= c;
  	}
  
  	kfree(buffer);
  
  	return (err) ? err : cnt;
  }
  
  static ssize_t
  fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
  {
  	unsigned long p = *ppos;
  	struct fb_info *info = file_fb_info(file);
  	u8 *buffer, *src;
  	u8 __iomem *dst;
  	int c, cnt = 0, err = 0;
  	unsigned long total_size;
  
  	if (!info || !info->screen_base)
  		return -ENODEV;
  
  	if (info->state != FBINFO_STATE_RUNNING)
  		return -EPERM;
  
  	if (info->fbops->fb_write)
  		return info->fbops->fb_write(info, buf, count, ppos);
  	
  	total_size = info->screen_size;
  
  	if (total_size == 0)
  		total_size = info->fix.smem_len;
  
  	if (p > total_size)
  		return -EFBIG;
  
  	if (count > total_size) {
  		err = -EFBIG;
  		count = total_size;
  	}
  
  	if (count + p > total_size) {
  		if (!err)
  			err = -ENOSPC;
  
  		count = total_size - p;
  	}
  
  	buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count,
  			 GFP_KERNEL);
  	if (!buffer)
  		return -ENOMEM;
  
  	dst = (u8 __iomem *) (info->screen_base + p);
  
  	if (info->fbops->fb_sync)
  		info->fbops->fb_sync(info);
  
  	while (count) {
  		c = (count > PAGE_SIZE) ? PAGE_SIZE : count;
  		src = buffer;
  
  		if (copy_from_user(src, buf, c)) {
  			err = -EFAULT;
  			break;
  		}
  
  		fb_memcpy_tofb(dst, src, c);
  		dst += c;
  		src += c;
  		*ppos += c;
  		buf += c;
  		cnt += c;
  		count -= c;
  	}
  
  	kfree(buffer);
  
  	return (cnt) ? cnt : err;
  }
  
  int
  fb_pan_display(struct fb_info *info, struct fb_var_screeninfo *var)
  {
  	struct fb_fix_screeninfo *fix = &info->fix;
  	unsigned int yres = info->var.yres;
  	int err = 0;
  
  	if (var->yoffset > 0) {
  		if (var->vmode & FB_VMODE_YWRAP) {
  			if (!fix->ywrapstep || (var->yoffset % fix->ywrapstep))
  				err = -EINVAL;
  			else
  				yres = 0;
  		} else if (!fix->ypanstep || (var->yoffset % fix->ypanstep))
  			err = -EINVAL;
  	}
  
  	if (var->xoffset > 0 && (!fix->xpanstep ||
  				 (var->xoffset % fix->xpanstep)))
  		err = -EINVAL;
  
  	if (err || !info->fbops->fb_pan_display ||
  	    var->yoffset > info->var.yres_virtual - yres ||
  	    var->xoffset > info->var.xres_virtual - info->var.xres)
  		return -EINVAL;
  
  	if ((err = info->fbops->fb_pan_display(var, info)))
  		return err;
  	info->var.xoffset = var->xoffset;
  	info->var.yoffset = var->yoffset;
  	if (var->vmode & FB_VMODE_YWRAP)
  		info->var.vmode |= FB_VMODE_YWRAP;
  	else
  		info->var.vmode &= ~FB_VMODE_YWRAP;
  	return 0;
  }
  EXPORT_SYMBOL(fb_pan_display);
  
  static int fb_check_caps(struct fb_info *info, struct fb_var_screeninfo *var,
  			 u32 activate)
  {
  	struct fb_event event;
  	struct fb_blit_caps caps, fbcaps;
  	int err = 0;
  
  	memset(&caps, 0, sizeof(caps));
  	memset(&fbcaps, 0, sizeof(fbcaps));
  	caps.flags = (activate & FB_ACTIVATE_ALL) ? 1 : 0;
  	event.info = info;
  	event.data = &caps;
  	fb_notifier_call_chain(FB_EVENT_GET_REQ, &event);
  	info->fbops->fb_get_caps(info, &fbcaps, var);
  
  	if (((fbcaps.x ^ caps.x) & caps.x) ||
  	    ((fbcaps.y ^ caps.y) & caps.y) ||
  	    (fbcaps.len < caps.len))
  		err = -EINVAL;
  
  	return err;
  }
  
  int
  fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
  {
  	int flags = info->flags;
  	int ret = 0;
  
  	if (var->activate & FB_ACTIVATE_INV_MODE) {
  		struct fb_videomode mode1, mode2;
  
  		fb_var_to_videomode(&mode1, var);
  		fb_var_to_videomode(&mode2, &info->var);
  		/* make sure we don't delete the videomode of current var */
  		ret = fb_mode_is_equal(&mode1, &mode2);
  
  		if (!ret) {
  		    struct fb_event event;
  
  		    event.info = info;
  		    event.data = &mode1;
  		    ret = fb_notifier_call_chain(FB_EVENT_MODE_DELETE, &event);
  		}
  
  		if (!ret)
  		    fb_delete_videomode(&mode1, &info->modelist);
  
  
  		ret = (ret) ? -EINVAL : 0;
  		goto done;
  	}
  
  	if ((var->activate & FB_ACTIVATE_FORCE) ||
  	    memcmp(&info->var, var, sizeof(struct fb_var_screeninfo))) {
  		u32 activate = var->activate;
  
  		/* When using FOURCC mode, make sure the red, green, blue and
  		 * transp fields are set to 0.
  		 */
  		if ((info->fix.capabilities & FB_CAP_FOURCC) &&
  		    var->grayscale > 1) {
  			if (var->red.offset     || var->green.offset    ||
  			    var->blue.offset    || var->transp.offset   ||
  			    var->red.length     || var->green.length    ||
  			    var->blue.length    || var->transp.length   ||
  			    var->red.msb_right  || var->green.msb_right ||
  			    var->blue.msb_right || var->transp.msb_right)
  				return -EINVAL;
  		}
  
  		if (!info->fbops->fb_check_var) {
  			*var = info->var;
  			goto done;
  		}
  
  		ret = info->fbops->fb_check_var(var, info);
  
  		if (ret)
  			goto done;
  
  		if ((var->activate & FB_ACTIVATE_MASK) == FB_ACTIVATE_NOW) {
  			struct fb_var_screeninfo old_var;
  			struct fb_videomode mode;
  
  			if (info->fbops->fb_get_caps) {
  				ret = fb_check_caps(info, var, activate);
  
  				if (ret)
  					goto done;
  			}
  
  			old_var = info->var;
  			info->var = *var;
  
  			if (info->fbops->fb_set_par) {
  				ret = info->fbops->fb_set_par(info);
  
  				if (ret) {
  					info->var = old_var;
  					printk(KERN_WARNING "detected "
  						"fb_set_par error, "
  						"error code: %d\n", ret);
  					goto done;
  				}
  			}
  
  			fb_pan_display(info, &info->var);
  			fb_set_cmap(&info->cmap, info);
  			fb_var_to_videomode(&mode, &info->var);
  
  			if (info->modelist.prev && info->modelist.next &&
  			    !list_empty(&info->modelist))
  				ret = fb_add_videomode(&mode, &info->modelist);
  
  			if (!ret && (flags & FBINFO_MISC_USEREVENT)) {
  				struct fb_event event;
  				int evnt = (activate & FB_ACTIVATE_ALL) ?
  					FB_EVENT_MODE_CHANGE_ALL :
  					FB_EVENT_MODE_CHANGE;
  
  				info->flags &= ~FBINFO_MISC_USEREVENT;
  				event.info = info;
  				event.data = &mode;
  				fb_notifier_call_chain(evnt, &event);
  			}
  		}
  	}
  
   done:
  	return ret;
  }
  EXPORT_SYMBOL(fb_set_var);
  
  int
  fb_blank(struct fb_info *info, int blank)
  {	
  	struct fb_event event;
  	int ret = -EINVAL, early_ret;
  
   	if (blank > FB_BLANK_POWERDOWN)
   		blank = FB_BLANK_POWERDOWN;
  
  	event.info = info;
  	event.data = &blank;
  
  	early_ret = fb_notifier_call_chain(FB_EARLY_EVENT_BLANK, &event);
  
  	if (info->fbops->fb_blank)
   		ret = info->fbops->fb_blank(blank, info);
  
  	if (!ret)
  		fb_notifier_call_chain(FB_EVENT_BLANK, &event);
  	else {
  		/*
  		 * if fb_blank is failed then revert effects of
  		 * the early blank event.
  		 */
  		if (!early_ret)
  			fb_notifier_call_chain(FB_R_EARLY_EVENT_BLANK, &event);
  	}
  
   	return ret;
  }
  EXPORT_SYMBOL(fb_blank);
  
  static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
  			unsigned long arg)
  {
  	struct fb_ops *fb;
  	struct fb_var_screeninfo var;
  	struct fb_fix_screeninfo fix;
  	struct fb_con2fbmap con2fb;
  	struct fb_cmap cmap_from;
  	struct fb_cmap_user cmap;
  	struct fb_event event;
  	void __user *argp = (void __user *)arg;
  	long ret = 0;
  
  	switch (cmd) {
  	case FBIOGET_VSCREENINFO:
  		if (!lock_fb_info(info))
  			return -ENODEV;
  		var = info->var;
  		unlock_fb_info(info);
  
  		ret = copy_to_user(argp, &var, sizeof(var)) ? -EFAULT : 0;
  		break;
  	case FBIOPUT_VSCREENINFO:
  		if (copy_from_user(&var, argp, sizeof(var)))
  			return -EFAULT;
  		console_lock();
  		if (!lock_fb_info(info)) {
  			console_unlock();
  			return -ENODEV;
  		}
  		info->flags |= FBINFO_MISC_USEREVENT;
  		ret = fb_set_var(info, &var);
  		info->flags &= ~FBINFO_MISC_USEREVENT;
  		unlock_fb_info(info);
  		console_unlock();
  		if (!ret && copy_to_user(argp, &var, sizeof(var)))
  			ret = -EFAULT;
  		break;
  	case FBIOGET_FSCREENINFO:
  		if (!lock_fb_info(info))
  			return -ENODEV;
  		fix = info->fix;
  		if (info->flags & FBINFO_HIDE_SMEM_START)
  			fix.smem_start = 0;
  		unlock_fb_info(info);
  
  		ret = copy_to_user(argp, &fix, sizeof(fix)) ? -EFAULT : 0;
  		break;
  	case FBIOPUTCMAP:
  		if (copy_from_user(&cmap, argp, sizeof(cmap)))
  			return -EFAULT;
  		ret = fb_set_user_cmap(&cmap, info);
  		break;
  	case FBIOGETCMAP:
  		if (copy_from_user(&cmap, argp, sizeof(cmap)))
  			return -EFAULT;
  		if (!lock_fb_info(info))
  			return -ENODEV;
  		cmap_from = info->cmap;
  		unlock_fb_info(info);
  		ret = fb_cmap_to_user(&cmap_from, &cmap);
  		break;
  	case FBIOPAN_DISPLAY:
  		if (copy_from_user(&var, argp, sizeof(var)))
  			return -EFAULT;
  		console_lock();
  		if (!lock_fb_info(info)) {
  			console_unlock();
  			return -ENODEV;
  		}
  		ret = fb_pan_display(info, &var);
  		unlock_fb_info(info);
  		console_unlock();
  		if (ret == 0 && copy_to_user(argp, &var, sizeof(var)))
  			return -EFAULT;
  		break;
  	case FBIO_CURSOR:
  		ret = -EINVAL;
  		break;
  	case FBIOGET_CON2FBMAP:
  		if (copy_from_user(&con2fb, argp, sizeof(con2fb)))
  			return -EFAULT;
  		if (con2fb.console < 1 || con2fb.console > MAX_NR_CONSOLES)
  			return -EINVAL;
  		con2fb.framebuffer = -1;
  		event.data = &con2fb;
  		if (!lock_fb_info(info))
  			return -ENODEV;
  		event.info = info;
  		fb_notifier_call_chain(FB_EVENT_GET_CONSOLE_MAP, &event);
  		unlock_fb_info(info);
  		ret = copy_to_user(argp, &con2fb, sizeof(con2fb)) ? -EFAULT : 0;
  		break;
  	case FBIOPUT_CON2FBMAP:
  		if (copy_from_user(&con2fb, argp, sizeof(con2fb)))
  			return -EFAULT;
  		if (con2fb.console < 1 || con2fb.console > MAX_NR_CONSOLES)
  			return -EINVAL;
  		if (con2fb.framebuffer >= FB_MAX)
  			return -EINVAL;
  		if (!registered_fb[con2fb.framebuffer])
  			request_module("fb%d", con2fb.framebuffer);
  		if (!registered_fb[con2fb.framebuffer]) {
  			ret = -EINVAL;
  			break;
  		}
  		event.data = &con2fb;
  		console_lock();
  		if (!lock_fb_info(info)) {
  			console_unlock();
  			return -ENODEV;
  		}
  		event.info = info;
  		ret = fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP, &event);
  		unlock_fb_info(info);
  		console_unlock();
  		break;
  	case FBIOBLANK:
  		console_lock();
  		if (!lock_fb_info(info)) {
  			console_unlock();
  			return -ENODEV;
  		}
  		info->flags |= FBINFO_MISC_USEREVENT;
  		ret = fb_blank(info, arg);
  		info->flags &= ~FBINFO_MISC_USEREVENT;
  		unlock_fb_info(info);
  		console_unlock();
  		break;
  	default:
  		if (!lock_fb_info(info))
  			return -ENODEV;
  		fb = info->fbops;
  		if (fb->fb_ioctl)
  			ret = fb->fb_ioctl(info, cmd, arg);
  		else
  			ret = -ENOTTY;
  		unlock_fb_info(info);
  	}
  	return ret;
  }
  
  static long fb_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  {
  	struct fb_info *info = file_fb_info(file);
  
  	if (!info)
  		return -ENODEV;
  	return do_fb_ioctl(info, cmd, arg);
  }
  
  #ifdef CONFIG_COMPAT
  struct fb_fix_screeninfo32 {
  	char			id[16];
  	compat_caddr_t		smem_start;
  	u32			smem_len;
  	u32			type;
  	u32			type_aux;
  	u32			visual;
  	u16			xpanstep;
  	u16			ypanstep;
  	u16			ywrapstep;
  	u32			line_length;
  	compat_caddr_t		mmio_start;
  	u32			mmio_len;
  	u32			accel;
  	u16			reserved[3];
  };
  
  struct fb_cmap32 {
  	u32			start;
  	u32			len;
  	compat_caddr_t	red;
  	compat_caddr_t	green;
  	compat_caddr_t	blue;
  	compat_caddr_t	transp;
  };
  
  static int fb_getput_cmap(struct fb_info *info, unsigned int cmd,
  			  unsigned long arg)
  {
  	struct fb_cmap_user __user *cmap;
  	struct fb_cmap32 __user *cmap32;
  	__u32 data;
  	int err;
  
  	cmap = compat_alloc_user_space(sizeof(*cmap));
  	cmap32 = compat_ptr(arg);
  
  	if (copy_in_user(&cmap->start, &cmap32->start, 2 * sizeof(__u32)))
  		return -EFAULT;
  
  	if (get_user(data, &cmap32->red) ||
  	    put_user(compat_ptr(data), &cmap->red) ||
  	    get_user(data, &cmap32->green) ||
  	    put_user(compat_ptr(data), &cmap->green) ||
  	    get_user(data, &cmap32->blue) ||
  	    put_user(compat_ptr(data), &cmap->blue) ||
  	    get_user(data, &cmap32->transp) ||
  	    put_user(compat_ptr(data), &cmap->transp))
  		return -EFAULT;
  
  	err = do_fb_ioctl(info, cmd, (unsigned long) cmap);
  
  	if (!err) {
  		if (copy_in_user(&cmap32->start,
  				 &cmap->start,
  				 2 * sizeof(__u32)))
  			err = -EFAULT;
  	}
  	return err;
  }
  
  static int do_fscreeninfo_to_user(struct fb_fix_screeninfo *fix,
  				  struct fb_fix_screeninfo32 __user *fix32)
  {
  	__u32 data;
  	int err;
  
  	err = copy_to_user(&fix32->id, &fix->id, sizeof(fix32->id));
  
  	data = (__u32) (unsigned long) fix->smem_start;
  	err |= put_user(data, &fix32->smem_start);
  
  	err |= put_user(fix->smem_len, &fix32->smem_len);
  	err |= put_user(fix->type, &fix32->type);
  	err |= put_user(fix->type_aux, &fix32->type_aux);
  	err |= put_user(fix->visual, &fix32->visual);
  	err |= put_user(fix->xpanstep, &fix32->xpanstep);
  	err |= put_user(fix->ypanstep, &fix32->ypanstep);
  	err |= put_user(fix->ywrapstep, &fix32->ywrapstep);
  	err |= put_user(fix->line_length, &fix32->line_length);
  
  	data = (__u32) (unsigned long) fix->mmio_start;
  	err |= put_user(data, &fix32->mmio_start);
  
  	err |= put_user(fix->mmio_len, &fix32->mmio_len);
  	err |= put_user(fix->accel, &fix32->accel);
  	err |= copy_to_user(fix32->reserved, fix->reserved,
  			    sizeof(fix->reserved));
  
  	if (err)
  		return -EFAULT;
  	return 0;
  }
  
  static int fb_get_fscreeninfo(struct fb_info *info, unsigned int cmd,
  			      unsigned long arg)
  {
  	struct fb_fix_screeninfo fix;
  
  	if (!lock_fb_info(info))
  		return -ENODEV;
  	fix = info->fix;
  	if (info->flags & FBINFO_HIDE_SMEM_START)
  		fix.smem_start = 0;
  	unlock_fb_info(info);
  	return do_fscreeninfo_to_user(&fix, compat_ptr(arg));
  }
  
  static long fb_compat_ioctl(struct file *file, unsigned int cmd,
  			    unsigned long arg)
  {
  	struct fb_info *info = file_fb_info(file);
  	struct fb_ops *fb;
  	long ret = -ENOIOCTLCMD;
  
  	if (!info)
  		return -ENODEV;
  	fb = info->fbops;
  	switch(cmd) {
  	case FBIOGET_VSCREENINFO:
  	case FBIOPUT_VSCREENINFO:
  	case FBIOPAN_DISPLAY:
  	case FBIOGET_CON2FBMAP:
  	case FBIOPUT_CON2FBMAP:
  		arg = (unsigned long) compat_ptr(arg);
  		/* fall through */
  	case FBIOBLANK:
  		ret = do_fb_ioctl(info, cmd, arg);
  		break;
  
  	case FBIOGET_FSCREENINFO:
  		ret = fb_get_fscreeninfo(info, cmd, arg);
  		break;
  
  	case FBIOGETCMAP:
  	case FBIOPUTCMAP:
  		ret = fb_getput_cmap(info, cmd, arg);
  		break;
  
  	default:
  		if (fb->fb_compat_ioctl)
  			ret = fb->fb_compat_ioctl(info, cmd, arg);
  		break;
  	}
  	return ret;
  }
  #endif
  
  static int
  fb_mmap(struct file *file, struct vm_area_struct * vma)
  {
  	struct fb_info *info = file_fb_info(file);
  	struct fb_ops *fb;
  	unsigned long mmio_pgoff;
  	unsigned long start;
  	u32 len;
  
  	if (!info)
  		return -ENODEV;
  	fb = info->fbops;
  	if (!fb)
  		return -ENODEV;
  	mutex_lock(&info->mm_lock);
  	if (fb->fb_mmap) {
  		int res;
  
  		/*
  		 * The framebuffer needs to be accessed decrypted, be sure
  		 * SME protection is removed ahead of the call
  		 */
  		vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
  		res = fb->fb_mmap(info, vma);
  		mutex_unlock(&info->mm_lock);
  		return res;
  	}
  
  	/*
  	 * Ugh. This can be either the frame buffer mapping, or
  	 * if pgoff points past it, the mmio mapping.
  	 */
  	start = info->fix.smem_start;
  	len = info->fix.smem_len;
  	mmio_pgoff = PAGE_ALIGN((start & ~PAGE_MASK) + len) >> PAGE_SHIFT;
  	if (vma->vm_pgoff >= mmio_pgoff) {
  		if (info->var.accel_flags) {
  			mutex_unlock(&info->mm_lock);
  			return -EINVAL;
  		}
  
  		vma->vm_pgoff -= mmio_pgoff;
  		start = info->fix.mmio_start;
  		len = info->fix.mmio_len;
  	}
  	mutex_unlock(&info->mm_lock);
  
  	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
  	/*
  	 * The framebuffer needs to be accessed decrypted, be sure
  	 * SME protection is removed
  	 */
  	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
  	fb_pgprotect(file, vma, start);
  
  	return vm_iomap_memory(vma, start, len);
  }
  
  static int
  fb_open(struct inode *inode, struct file *file)
  __acquires(&info->lock)
  __releases(&info->lock)
  {
  	int fbidx = iminor(inode);
  	struct fb_info *info;
  	int res = 0;
  
  	info = get_fb_info(fbidx);
  	if (!info) {
  		request_module("fb%d", fbidx);
  		info = get_fb_info(fbidx);
  		if (!info)
  			return -ENODEV;
  	}
  	if (IS_ERR(info))
  		return PTR_ERR(info);
  
  	mutex_lock(&info->lock);
  	if (!try_module_get(info->fbops->owner)) {
  		res = -ENODEV;
  		goto out;
  	}
  	file->private_data = info;
  	if (info->fbops->fb_open) {
  		res = info->fbops->fb_open(info,1);
  		if (res)
  			module_put(info->fbops->owner);
  	}
  #ifdef CONFIG_FB_DEFERRED_IO
  	if (info->fbdefio)
  		fb_deferred_io_open(info, inode, file);
  #endif
  out:
  	mutex_unlock(&info->lock);
  	if (res)
  		put_fb_info(info);
  	return res;
  }
  
  static int 
  fb_release(struct inode *inode, struct file *file)
  __acquires(&info->lock)
  __releases(&info->lock)
  {
  	struct fb_info * const info = file->private_data;
  
  	mutex_lock(&info->lock);
  	if (info->fbops->fb_release)
  		info->fbops->fb_release(info,1);
  	module_put(info->fbops->owner);
  	mutex_unlock(&info->lock);
  	put_fb_info(info);
  	return 0;
  }
  
  #if defined(CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA) && !defined(CONFIG_MMU)
  unsigned long get_fb_unmapped_area(struct file *filp,
  				   unsigned long addr, unsigned long len,
  				   unsigned long pgoff, unsigned long flags)
  {
  	struct fb_info * const info = filp->private_data;
  	unsigned long fb_size = PAGE_ALIGN(info->fix.smem_len);
  
  	if (pgoff > fb_size || len > fb_size - pgoff)
  		return -EINVAL;
  
  	return (unsigned long)info->screen_base + pgoff;
  }
  #endif
  
  static const struct file_operations fb_fops = {
  	.owner =	THIS_MODULE,
  	.read =		fb_read,
  	.write =	fb_write,
  	.unlocked_ioctl = fb_ioctl,
  #ifdef CONFIG_COMPAT
  	.compat_ioctl = fb_compat_ioctl,
  #endif
  	.mmap =		fb_mmap,
  	.open =		fb_open,
  	.release =	fb_release,
  #if defined(HAVE_ARCH_FB_UNMAPPED_AREA) || \
  	(defined(CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA) && \
  	 !defined(CONFIG_MMU))
  	.get_unmapped_area = get_fb_unmapped_area,
  #endif
  #ifdef CONFIG_FB_DEFERRED_IO
  	.fsync =	fb_deferred_io_fsync,
  #endif
  	.llseek =	default_llseek,
  };
  
  struct class *fb_class;
  EXPORT_SYMBOL(fb_class);
  
  static int fb_check_foreignness(struct fb_info *fi)
  {
  	const bool foreign_endian = fi->flags & FBINFO_FOREIGN_ENDIAN;
  
  	fi->flags &= ~FBINFO_FOREIGN_ENDIAN;
  
  #ifdef __BIG_ENDIAN
  	fi->flags |= foreign_endian ? 0 : FBINFO_BE_MATH;
  #else
  	fi->flags |= foreign_endian ? FBINFO_BE_MATH : 0;
  #endif /* __BIG_ENDIAN */
  
  	if (fi->flags & FBINFO_BE_MATH && !fb_be_math(fi)) {
  		pr_err("%s: enable CONFIG_FB_BIG_ENDIAN to "
  		       "support this framebuffer\n", fi->fix.id);
  		return -ENOSYS;
  	} else if (!(fi->flags & FBINFO_BE_MATH) && fb_be_math(fi)) {
  		pr_err("%s: enable CONFIG_FB_LITTLE_ENDIAN to "
  		       "support this framebuffer\n", fi->fix.id);
  		return -ENOSYS;
  	}
  
  	return 0;
  }
  
  static bool apertures_overlap(struct aperture *gen, struct aperture *hw)
  {
  	/* is the generic aperture base the same as the HW one */
  	if (gen->base == hw->base)
  		return true;
  	/* is the generic aperture base inside the hw base->hw base+size */
  	if (gen->base > hw->base && gen->base < hw->base + hw->size)
  		return true;
  	return false;
  }
  
  static bool fb_do_apertures_overlap(struct apertures_struct *gena,
  				    struct apertures_struct *hwa)
  {
  	int i, j;
  	if (!hwa || !gena)
  		return false;
  
  	for (i = 0; i < hwa->count; ++i) {
  		struct aperture *h = &hwa->ranges[i];
  		for (j = 0; j < gena->count; ++j) {
  			struct aperture *g = &gena->ranges[j];
  			printk(KERN_DEBUG "checking generic (%llx %llx) vs hw (%llx %llx)\n",
  				(unsigned long long)g->base,
  				(unsigned long long)g->size,
  				(unsigned long long)h->base,
  				(unsigned long long)h->size);
  			if (apertures_overlap(g, h))
  				return true;
  		}
  	}
  
  	return false;
  }
  
  static int do_unregister_framebuffer(struct fb_info *fb_info);
  
  #define VGA_FB_PHYS 0xA0000
  static int do_remove_conflicting_framebuffers(struct apertures_struct *a,
  					      const char *name, bool primary)
  {
  	int i, ret;
  
  	/* check all firmware fbs and kick off if the base addr overlaps */
  	for_each_registered_fb(i) {
  		struct apertures_struct *gen_aper;
  
  		if (!(registered_fb[i]->flags & FBINFO_MISC_FIRMWARE))
  			continue;
  
  		gen_aper = registered_fb[i]->apertures;
  		if (fb_do_apertures_overlap(gen_aper, a) ||
  			(primary && gen_aper && gen_aper->count &&
  			 gen_aper->ranges[0].base == VGA_FB_PHYS)) {
  
  			printk(KERN_INFO "fb%d: switching to %s from %s\n",
  			       i, name, registered_fb[i]->fix.id);
  			ret = do_unregister_framebuffer(registered_fb[i]);
  			if (ret)
  				return ret;
  		}
  	}
  
  	return 0;
  }
  
  static bool lockless_register_fb;
  module_param_named_unsafe(lockless_register_fb, lockless_register_fb, bool, 0400);
  MODULE_PARM_DESC(lockless_register_fb,
  	"Lockless framebuffer registration for debugging [default=off]");
  
  static int do_register_framebuffer(struct fb_info *fb_info)
  {
  	int i, ret;
  	struct fb_event event;
  	struct fb_videomode mode;
  
  	if (fb_check_foreignness(fb_info))
  		return -ENOSYS;
  
  	ret = do_remove_conflicting_framebuffers(fb_info->apertures,
  						 fb_info->fix.id,
  						 fb_is_primary_device(fb_info));
  	if (ret)
  		return ret;
  
  	if (num_registered_fb == FB_MAX)
  		return -ENXIO;
  
  	num_registered_fb++;
  	for (i = 0 ; i < FB_MAX; i++)
  		if (!registered_fb[i])
  			break;
  	fb_info->node = i;
  	atomic_set(&fb_info->count, 1);
  	mutex_init(&fb_info->lock);
  	mutex_init(&fb_info->mm_lock);
  
  	fb_info->dev = device_create(fb_class, fb_info->device,
  				     MKDEV(FB_MAJOR, i), NULL, "fb%d", i);
  	if (IS_ERR(fb_info->dev)) {
  		/* Not fatal */
  		printk(KERN_WARNING "Unable to create device for framebuffer %d; errno = %ld\n", i, PTR_ERR(fb_info->dev));
  		fb_info->dev = NULL;
  	} else
  		fb_init_device(fb_info);
  
  	if (fb_info->pixmap.addr == NULL) {
  		fb_info->pixmap.addr = kmalloc(FBPIXMAPSIZE, GFP_KERNEL);
  		if (fb_info->pixmap.addr) {
  			fb_info->pixmap.size = FBPIXMAPSIZE;
  			fb_info->pixmap.buf_align = 1;
  			fb_info->pixmap.scan_align = 1;
  			fb_info->pixmap.access_align = 32;
  			fb_info->pixmap.flags = FB_PIXMAP_DEFAULT;
  		}
  	}	
  	fb_info->pixmap.offset = 0;
  
  	if (!fb_info->pixmap.blit_x)
  		fb_info->pixmap.blit_x = ~(u32)0;
  
  	if (!fb_info->pixmap.blit_y)
  		fb_info->pixmap.blit_y = ~(u32)0;
  
  	if (!fb_info->modelist.prev || !fb_info->modelist.next)
  		INIT_LIST_HEAD(&fb_info->modelist);
  
  	if (fb_info->skip_vt_switch)
  		pm_vt_switch_required(fb_info->dev, false);
  	else
  		pm_vt_switch_required(fb_info->dev, true);
  
  	fb_var_to_videomode(&mode, &fb_info->var);
  	fb_add_videomode(&mode, &fb_info->modelist);
  	registered_fb[i] = fb_info;
  
  	event.info = fb_info;
  	if (!lockless_register_fb)
  		console_lock();
  	else
  		atomic_inc(&ignore_console_lock_warning);
  	if (!lock_fb_info(fb_info)) {
  		ret = -ENODEV;
  		goto unlock_console;
  	}
  	ret = 0;
  
  	fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
  	unlock_fb_info(fb_info);
  unlock_console:
  	if (!lockless_register_fb)
  		console_unlock();
  	else
  		atomic_dec(&ignore_console_lock_warning);
  	return ret;
  }
  
  static int unbind_console(struct fb_info *fb_info)
  {
  	struct fb_event event;
  	int ret;
  	int i = fb_info->node;
  
  	if (i < 0 || i >= FB_MAX || registered_fb[i] != fb_info)
  		return -EINVAL;
  
  	console_lock();
  	if (!lock_fb_info(fb_info)) {
  		console_unlock();
  		return -ENODEV;
  	}
  
  	event.info = fb_info;
  	ret = fb_notifier_call_chain(FB_EVENT_FB_UNBIND, &event);
  	unlock_fb_info(fb_info);
  	console_unlock();
  
  	return ret;
  }
  
  static int __unlink_framebuffer(struct fb_info *fb_info);
  
  static int do_unregister_framebuffer(struct fb_info *fb_info)
  {
  	struct fb_event event;
  	int ret;
  
  	ret = unbind_console(fb_info);
  
  	if (ret)
  		return -EINVAL;
  
  	pm_vt_switch_unregister(fb_info->dev);
  
  	__unlink_framebuffer(fb_info);
  	if (fb_info->pixmap.addr &&
  	    (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT))
  		kfree(fb_info->pixmap.addr);
  	fb_destroy_modelist(&fb_info->modelist);
  	registered_fb[fb_info->node] = NULL;
  	num_registered_fb--;
  	fb_cleanup_device(fb_info);
  	event.info = fb_info;
  	console_lock();
  	fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
  	console_unlock();
  
  	/* this may free fb info */
  	put_fb_info(fb_info);
  	return 0;
  }
  
  static int __unlink_framebuffer(struct fb_info *fb_info)
  {
  	int i;
  
  	i = fb_info->node;
  	if (i < 0 || i >= FB_MAX || registered_fb[i] != fb_info)
  		return -EINVAL;
  
  	if (fb_info->dev) {
  		device_destroy(fb_class, MKDEV(FB_MAJOR, i));
  		fb_info->dev = NULL;
  	}
  
  	return 0;
  }
  
  int unlink_framebuffer(struct fb_info *fb_info)
  {
  	int ret;
  
  	ret = __unlink_framebuffer(fb_info);
  	if (ret)
  		return ret;
  
  	unbind_console(fb_info);
  
  	return 0;
  }
  EXPORT_SYMBOL(unlink_framebuffer);
  
  /**
   * remove_conflicting_framebuffers - remove firmware-configured framebuffers
   * @a: memory range, users of which are to be removed
   * @name: requesting driver name
   * @primary: also kick vga16fb if present
   *
   * This function removes framebuffer devices (initialized by firmware/bootloader)
   * which use memory range described by @a. If @a is NULL all such devices are
   * removed.
   */
  int remove_conflicting_framebuffers(struct apertures_struct *a,
  				    const char *name, bool primary)
  {
  	int ret;
  	bool do_free = false;
  
  	if (!a) {
  		a = alloc_apertures(1);
  		if (!a)
  			return -ENOMEM;
  
  		a->ranges[0].base = 0;
  		a->ranges[0].size = ~0;
  		do_free = true;
  	}
  
  	mutex_lock(&registration_lock);
  	ret = do_remove_conflicting_framebuffers(a, name, primary);
  	mutex_unlock(&registration_lock);
  
  	if (do_free)
  		kfree(a);
  
  	return ret;
  }
  EXPORT_SYMBOL(remove_conflicting_framebuffers);
  
  /**
   * remove_conflicting_pci_framebuffers - remove firmware-configured framebuffers for PCI devices
   * @pdev: PCI device
   * @res_id: index of PCI BAR configuring framebuffer memory
   * @name: requesting driver name
   *
   * This function removes framebuffer devices (eg. initialized by firmware)
   * using memory range configured for @pdev's BAR @res_id.
   *
   * The function assumes that PCI device with shadowed ROM drives a primary
   * display and so kicks out vga16fb.
   */
  int remove_conflicting_pci_framebuffers(struct pci_dev *pdev, int res_id, const char *name)
  {
  	struct apertures_struct *ap;
  	bool primary = false;
  	int err, idx, bar;
  	bool res_id_found = false;
  
  	for (idx = 0, bar = 0; bar < PCI_ROM_RESOURCE; bar++) {
  		if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM))
  			continue;
  		idx++;
  	}
  
  	ap = alloc_apertures(idx);
  	if (!ap)
  		return -ENOMEM;
  
  	for (idx = 0, bar = 0; bar < PCI_ROM_RESOURCE; bar++) {
  		if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM))
  			continue;
  		ap->ranges[idx].base = pci_resource_start(pdev, bar);
  		ap->ranges[idx].size = pci_resource_len(pdev, bar);
  		pci_info(pdev, "%s: bar %d: 0x%lx -> 0x%lx\n", __func__, bar,
  			 (unsigned long)pci_resource_start(pdev, bar),
  			 (unsigned long)pci_resource_end(pdev, bar));
  		idx++;
  		if (res_id == bar)
  			res_id_found = true;
  	}
  	if (!res_id_found)
  		pci_warn(pdev, "%s: passed res_id (%d) is not a memory bar\n",
  			 __func__, res_id);
  
  #ifdef CONFIG_X86
  	primary = pdev->resource[PCI_ROM_RESOURCE].flags &
  					IORESOURCE_ROM_SHADOW;
  #endif
  	err = remove_conflicting_framebuffers(ap, name, primary);
  	kfree(ap);
  	return err;
  }
  EXPORT_SYMBOL(remove_conflicting_pci_framebuffers);
  
  /**
   *	register_framebuffer - registers a frame buffer device
   *	@fb_info: frame buffer info structure
   *
   *	Registers a frame buffer device @fb_info.
   *
   *	Returns negative errno on error, or zero for success.
   *
   */
  int
  register_framebuffer(struct fb_info *fb_info)
  {
  	int ret;
  
  	mutex_lock(&registration_lock);
  	ret = do_register_framebuffer(fb_info);
  	mutex_unlock(&registration_lock);
  
  	return ret;
  }
  EXPORT_SYMBOL(register_framebuffer);
  
  /**
   *	unregister_framebuffer - releases a frame buffer device
   *	@fb_info: frame buffer info structure
   *
   *	Unregisters a frame buffer device @fb_info.
   *
   *	Returns negative errno on error, or zero for success.
   *
   *      This function will also notify the framebuffer console
   *      to release the driver.
   *
   *      This is meant to be called within a driver's module_exit()
   *      function. If this is called outside module_exit(), ensure
   *      that the driver implements fb_open() and fb_release() to
   *      check that no processes are using the device.
   */
  int
  unregister_framebuffer(struct fb_info *fb_info)
  {
  	int ret;
  
  	mutex_lock(&registration_lock);
  	ret = do_unregister_framebuffer(fb_info);
  	mutex_unlock(&registration_lock);
  
  	return ret;
  }
  EXPORT_SYMBOL(unregister_framebuffer);
  
  /**
   *	fb_set_suspend - low level driver signals suspend
   *	@info: framebuffer affected
   *	@state: 0 = resuming, !=0 = suspending
   *
   *	This is meant to be used by low level drivers to
   * 	signal suspend/resume to the core & clients.
   *	It must be called with the console semaphore held
   */
  void fb_set_suspend(struct fb_info *info, int state)
  {
  	struct fb_event event;
  
  	event.info = info;
  	if (state) {
  		fb_notifier_call_chain(FB_EVENT_SUSPEND, &event);
  		info->state = FBINFO_STATE_SUSPENDED;
  	} else {
  		info->state = FBINFO_STATE_RUNNING;
  		fb_notifier_call_chain(FB_EVENT_RESUME, &event);
  	}
  }
  EXPORT_SYMBOL(fb_set_suspend);
  
  /**
   *	fbmem_init - init frame buffer subsystem
   *
   *	Initialize the frame buffer subsystem.
   *
   *	NOTE: This function is _only_ to be called by drivers/char/mem.c.
   *
   */
  
  static int __init
  fbmem_init(void)
  {
  	int ret;
  
  	if (!proc_create_seq("fb", 0, NULL, &proc_fb_seq_ops))
  		return -ENOMEM;
  
  	ret = register_chrdev(FB_MAJOR, "fb", &fb_fops);
  	if (ret) {
  		printk("unable to get major %d for fb devs\n", FB_MAJOR);
  		goto err_chrdev;
  	}
  
  	fb_class = class_create(THIS_MODULE, "graphics");
  	if (IS_ERR(fb_class)) {
  		ret = PTR_ERR(fb_class);
  		pr_warn("Unable to create fb class; errno = %d\n", ret);
  		fb_class = NULL;
  		goto err_class;
  	}
  
  	fb_console_init();
  
  	return 0;
  
  err_class:
  	unregister_chrdev(FB_MAJOR, "fb");
  err_chrdev:
  	remove_proc_entry("fb", NULL);
  	return ret;
  }
  
  #ifdef MODULE
  module_init(fbmem_init);
  static void __exit
  fbmem_exit(void)
  {
  	fb_console_exit();
  
  	remove_proc_entry("fb", NULL);
  	class_destroy(fb_class);
  	unregister_chrdev(FB_MAJOR, "fb");
  }
  
  module_exit(fbmem_exit);
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("Framebuffer base");
  #else
  subsys_initcall(fbmem_init);
  #endif
  
  int fb_new_modelist(struct fb_info *info)
  {
  	struct fb_event event;
  	struct fb_var_screeninfo var = info->var;
  	struct list_head *pos, *n;
  	struct fb_modelist *modelist;
  	struct fb_videomode *m, mode;
  	int err = 1;
  
  	list_for_each_safe(pos, n, &info->modelist) {
  		modelist = list_entry(pos, struct fb_modelist, list);
  		m = &modelist->mode;
  		fb_videomode_to_var(&var, m);
  		var.activate = FB_ACTIVATE_TEST;
  		err = fb_set_var(info, &var);
  		fb_var_to_videomode(&mode, &var);
  		if (err || !fb_mode_is_equal(m, &mode)) {
  			list_del(pos);
  			kfree(pos);
  		}
  	}
  
  	err = 1;
  
  	if (!list_empty(&info->modelist)) {
  		event.info = info;
  		err = fb_notifier_call_chain(FB_EVENT_NEW_MODELIST, &event);
  	}
  
  	return err;
  }
  
  MODULE_LICENSE("GPL");
  