OSCL-LXR linux-6.0.1/​drivers/​video/​fbdev/​core/​fbmem.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /*
  *  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/sysfb.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/platform_device.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;
 
 int fb_logo_count __read_mostly = -1;
 
 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)
         refcount_inc(&fb_info->count);
     mutex_unlock(&registration_lock);
 
     return fb_info;
 }
 
 static void put_fb_info(struct fb_info *fb_info)
 {
     if (!refcount_dec_and_test(&fb_info->count))
         return;
     if (fb_info->fbops->fb_destroy)
         fb_info->fbops->fb_destroy(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);
         swap(image->width, image->height);
         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);
         swap(image->width, image->height);
         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 || !fb_logo_count)
         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)
 {
     unsigned int count;
     int y;
 
     if (!fb_logo_count)
         return 0;
 
     count = fb_logo_count < 0 ? num_online_cpus() : fb_logo_count;
     y = fb_show_logo_line(info, rotate, fb_logo.logo, 0, count);
     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 __maybe_unused 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_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;
     fbcon_get_requirement(info, &caps);
     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 ret = 0;
     u32 activate;
     struct fb_var_screeninfo old_var;
     struct fb_videomode mode;
     struct fb_event event;
     u32 unused;
 
     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) {
             ret = fbcon_mode_deleted(info, &mode1);
             if (!ret)
                 fb_delete_videomode(&mode1, &info->modelist);
         }
 
         return ret ? -EINVAL : 0;
     }
 
     if (!(var->activate & FB_ACTIVATE_FORCE) &&
         !memcmp(&info->var, var, sizeof(struct fb_var_screeninfo)))
         return 0;
 
     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;
         return 0;
     }
 
     /* bitfill_aligned() assumes that it's at least 8x8 */
     if (var->xres < 8 || var->yres < 8)
         return -EINVAL;
 
     /* Too huge resolution causes multiplication overflow. */
     if (check_mul_overflow(var->xres, var->yres, &unused) ||
         check_mul_overflow(var->xres_virtual, var->yres_virtual, &unused))
         return -EINVAL;
 
     ret = info->fbops->fb_check_var(var, info);
 
     if (ret)
         return ret;
 
     /* verify that virtual resolution >= physical resolution */
     if (var->xres_virtual < var->xres ||
         var->yres_virtual < var->yres) {
         pr_warn("WARNING: fbcon: Driver '%s' missed to adjust virtual screen size (%ux%u vs. %ux%u)\n",
             info->fix.id,
             var->xres_virtual, var->yres_virtual,
             var->xres, var->yres);
         return -EINVAL;
     }
 
     if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW)
         return 0;
 
     if (info->fbops->fb_get_caps) {
         ret = fb_check_caps(info, var, activate);
 
         if (ret)
             return ret;
     }
 
     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);
             return ret;
         }
     }
 
     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)
         return ret;
 
     event.info = info;
     event.data = &mode;
     fb_notifier_call_chain(FB_EVENT_MODE_CHANGE, &event);
 
     return 0;
 }
 EXPORT_SYMBOL(fb_set_var);
 
 int
 fb_blank(struct fb_info *info, int blank)
 {
     struct fb_event event;
     int ret = -EINVAL;
 
     if (blank > FB_BLANK_POWERDOWN)
         blank = FB_BLANK_POWERDOWN;
 
     event.info = info;
     event.data = &blank;
 
     if (info->fbops->fb_blank)
         ret = info->fbops->fb_blank(blank, info);
 
     if (!ret)
         fb_notifier_call_chain(FB_EVENT_BLANK, &event);
 
     return ret;
 }
 EXPORT_SYMBOL(fb_blank);
 
 static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
             unsigned long arg)
 {
     const struct fb_ops *fb;
     struct fb_var_screeninfo var;
     struct fb_fix_screeninfo fix;
     struct fb_cmap cmap_from;
     struct fb_cmap_user cmap;
     void __user *argp = (void __user *)arg;
     long ret = 0;
 
     switch (cmd) {
     case FBIOGET_VSCREENINFO:
         lock_fb_info(info);
         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();
         lock_fb_info(info);
         ret = fbcon_modechange_possible(info, &var);
         if (!ret)
             ret = fb_set_var(info, &var);
         if (!ret)
             fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
         unlock_fb_info(info);
         console_unlock();
         if (!ret && copy_to_user(argp, &var, sizeof(var)))
             ret = -EFAULT;
         break;
     case FBIOGET_FSCREENINFO:
         lock_fb_info(info);
         memcpy(&fix, &info->fix, sizeof(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;
         lock_fb_info(info);
         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();
         lock_fb_info(info);
         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:
         ret = fbcon_get_con2fb_map_ioctl(argp);
         break;
     case FBIOPUT_CON2FBMAP:
         ret = fbcon_set_con2fb_map_ioctl(argp);
         break;
     case FBIOBLANK:
         if (arg > FB_BLANK_POWERDOWN)
             return -EINVAL;
         console_lock();
         lock_fb_info(info);
         ret = fb_blank(info, arg);
         /* might again call into fb_blank */
         fbcon_fb_blanked(info, arg);
         unlock_fb_info(info);
         console_unlock();
         break;
     default:
         lock_fb_info(info);
         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_cmap32 cmap32;
     struct fb_cmap cmap_from;
     struct fb_cmap_user cmap;
 
     if (copy_from_user(&cmap32, compat_ptr(arg), sizeof(cmap32)))
         return -EFAULT;
 
     cmap = (struct fb_cmap_user) {
         .start  = cmap32.start,
         .len    = cmap32.len,
         .red    = compat_ptr(cmap32.red),
         .green  = compat_ptr(cmap32.green),
         .blue   = compat_ptr(cmap32.blue),
         .transp = compat_ptr(cmap32.transp),
     };
 
     if (cmd == FBIOPUTCMAP)
         return fb_set_user_cmap(&cmap, info);
 
     lock_fb_info(info);
     cmap_from = info->cmap;
     unlock_fb_info(info);
 
     return fb_cmap_to_user(&cmap_from, &cmap);
 }
 
 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;
 
     lock_fb_info(info);
     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);
     const 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);
         fallthrough;
     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);
     unsigned long mmio_pgoff;
     unsigned long start;
     u32 len;
 
     if (!info)
         return -ENODEV;
     mutex_lock(&info->mm_lock);
 
     if (info->fbops->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 = info->fbops->fb_mmap(info, vma);
         mutex_unlock(&info->mm_lock);
         return res;
 #if IS_ENABLED(CONFIG_FB_DEFERRED_IO)
     } else if (info->fbdefio) {
         /*
          * FB deferred I/O wants you to handle mmap in your drivers. At a
          * minimum, point struct fb_ops.fb_mmap to fb_deferred_io_mmap().
          */
         dev_warn_once(info->dev, "fbdev mmap not set up for deferred I/O.\n");
         mutex_unlock(&info->mm_lock);
         return -ENODEV;
 #endif
     }
 
     /*
      * 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);
     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);
 
     lock_fb_info(info);
     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:
     unlock_fb_info(info);
     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;
 
     lock_fb_info(info);
     if (info->fbops->fb_release)
         info->fbops->fb_release(info,1);
     module_put(info->fbops->owner);
     unlock_fb_info(info);
     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 void do_unregister_framebuffer(struct fb_info *fb_info);
 
 #define VGA_FB_PHYS 0xA0000
 static void do_remove_conflicting_framebuffers(struct apertures_struct *a,
                            const char *name, bool primary)
 {
     int i;
 
 restart_removal:
     /* check all firmware fbs and kick off if the base addr overlaps */
     for_each_registered_fb(i) {
         struct apertures_struct *gen_aper;
         struct device *device;
 
         if (!(registered_fb[i]->flags & FBINFO_MISC_FIRMWARE))
             continue;
 
         gen_aper = registered_fb[i]->apertures;
         device = registered_fb[i]->device;
         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);
 
             /*
              * If we kick-out a firmware driver, we also want to remove
              * the underlying platform device, such as simple-framebuffer,
              * VESA, EFI, etc. A native driver will then be able to
              * allocate the memory range.
              *
              * If it's not a platform device, at least print a warning. A
              * fix would add code to remove the device from the system. For
              * framebuffers without any Linux device, print a warning as
              * well.
              */
             if (!device) {
                 pr_warn("fb%d: no device set\n", i);
                 do_unregister_framebuffer(registered_fb[i]);
             } else if (dev_is_platform(device)) {
                 /*
                  * Drop the lock because if the device is unregistered, its
                  * driver will call to unregister_framebuffer(), that takes
                  * this lock.
                  */
                 mutex_unlock(&registration_lock);
                 platform_device_unregister(to_platform_device(device));
                 mutex_lock(&registration_lock);
             } else {
                 pr_warn("fb%d: cannot remove device\n", i);
                 do_unregister_framebuffer(registered_fb[i]);
             }
             /*
              * Restart the removal loop now that the device has been
              * unregistered and its associated framebuffer gone.
              */
             goto restart_removal;
         }
     }
 }
 
 static int do_register_framebuffer(struct fb_info *fb_info)
 {
     int i;
     struct fb_videomode mode;
 
     if (fb_check_foreignness(fb_info))
         return -ENOSYS;
 
     do_remove_conflicting_framebuffers(fb_info->apertures,
                        fb_info->fix.id,
                        fb_is_primary_device(fb_info));
 
     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;
     refcount_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;
 
 #ifdef CONFIG_GUMSTIX_AM200EPD
     {
         struct fb_event event;
         event.info = fb_info;
         fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
     }
 #endif
 
     return fbcon_fb_registered(fb_info);
 }
 
 static void unbind_console(struct fb_info *fb_info)
 {
     int i = fb_info->node;
 
     if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info))
         return;
 
     fbcon_fb_unbind(fb_info);
 }
 
 static void unlink_framebuffer(struct fb_info *fb_info)
 {
     int i;
 
     i = fb_info->node;
     if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info))
         return;
 
     if (!fb_info->dev)
         return;
 
     device_destroy(fb_class, MKDEV(FB_MAJOR, i));
 
     pm_vt_switch_unregister(fb_info->dev);
 
     unbind_console(fb_info);
 
     fb_info->dev = NULL;
 }
 
 static void do_unregister_framebuffer(struct fb_info *fb_info)
 {
     unlink_framebuffer(fb_info);
     if (fb_info->pixmap.addr &&
         (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT)) {
         kfree(fb_info->pixmap.addr);
         fb_info->pixmap.addr = NULL;
     }
 
     fb_destroy_modelist(&fb_info->modelist);
     registered_fb[fb_info->node] = NULL;
     num_registered_fb--;
     fb_cleanup_device(fb_info);
 #ifdef CONFIG_GUMSTIX_AM200EPD
     {
         struct fb_event event;
         event.info = fb_info;
         fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
     }
 #endif
     fbcon_fb_unregistered(fb_info);
 
     /* this may free fb info */
     put_fb_info(fb_info);
 }
 
 /**
  * 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)
 {
     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;
     }
 
     /*
      * If a driver asked to unregister a platform device registered by
      * sysfb, then can be assumed that this is a driver for a display
      * that is set up by the system firmware and has a generic driver.
      *
      * Drivers for devices that don't have a generic driver will never
      * ask for this, so let's assume that a real driver for the display
      * was already probed and prevent sysfb to register devices later.
      */
     sysfb_disable();
 
     mutex_lock(&registration_lock);
     do_remove_conflicting_framebuffers(a, name, primary);
     mutex_unlock(&registration_lock);
 
     if (do_free)
         kfree(a);
 
     return 0;
 }
 EXPORT_SYMBOL(remove_conflicting_framebuffers);
 
 /**
  * remove_conflicting_pci_framebuffers - remove firmware-configured framebuffers for PCI devices
  * @pdev: PCI device
  * @name: requesting driver name
  *
  * This function removes framebuffer devices (eg. initialized by firmware)
  * using memory range configured for any of @pdev's memory bars.
  *
  * 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, const char *name)
 {
     struct apertures_struct *ap;
     bool primary = false;
     int err, idx, bar;
 
     for (idx = 0, bar = 0; bar < PCI_STD_NUM_BARS; 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_STD_NUM_BARS; 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_dbg(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++;
     }
 
 #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.
  */
 void
 unregister_framebuffer(struct fb_info *fb_info)
 {
     mutex_lock(&registration_lock);
     do_unregister_framebuffer(fb_info);
     mutex_unlock(&registration_lock);
 }
 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)
 {
     WARN_CONSOLE_UNLOCKED();
 
     if (state) {
         fbcon_suspended(info);
         info->state = FBINFO_STATE_SUSPENDED;
     } else {
         info->state = FBINFO_STATE_RUNNING;
         fbcon_resumed(info);
     }
 }
 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_var_screeninfo var = info->var;
     struct list_head *pos, *n;
     struct fb_modelist *modelist;
     struct fb_videomode *m, mode;
     int err;
 
     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);
         }
     }
 
     if (list_empty(&info->modelist))
         return 1;
 
     fbcon_new_modelist(info);
 
     return 0;
 }
 
 MODULE_LICENSE("GPL");

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