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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 | // SPDX-License-Identifier: GPL-2.0 #include <linux/fb.h> #include <linux/module.h> #include <linux/uaccess.h> ssize_t fb_io_read(struct fb_info *info, char __user *buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; u8 *buffer, *dst; u8 __iomem *src; int c, cnt = 0, err = 0; unsigned long total_size, trailing; if (info->flags & FBINFO_VIRTFB) fb_warn_once(info, "Framebuffer is not in I/O address space."); if (!info->screen_base) return -ENODEV; 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_fromio(dst, src, c); dst += c; src += c; trailing = copy_to_user(buf, buffer, c); if (trailing == c) { err = -EFAULT; break; } c -= trailing; *ppos += c; buf += c; cnt += c; count -= c; } kfree(buffer); return cnt ? cnt : err; } EXPORT_SYMBOL(fb_io_read); ssize_t fb_io_write(struct fb_info *info, const char __user *buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; u8 *buffer, *src; u8 __iomem *dst; int c, cnt = 0, err = 0; unsigned long total_size, trailing; if (info->flags & FBINFO_VIRTFB) fb_warn_once(info, "Framebuffer is not in I/O address space."); if (!info->screen_base) return -ENODEV; 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; trailing = copy_from_user(src, buf, c); if (trailing == c) { err = -EFAULT; break; } c -= trailing; fb_memcpy_toio(dst, src, c); dst += c; src += c; *ppos += c; buf += c; cnt += c; count -= c; } kfree(buffer); return (cnt) ? cnt : err; } EXPORT_SYMBOL(fb_io_write); int fb_io_mmap(struct fb_info *info, struct vm_area_struct *vma) { unsigned long start = info->fix.smem_start; u32 len = info->fix.smem_len; unsigned long mmio_pgoff = PAGE_ALIGN((start & ~PAGE_MASK) + len) >> PAGE_SHIFT; if (info->flags & FBINFO_VIRTFB) fb_warn_once(info, "Framebuffer is not in I/O address space."); /* * This can be either the framebuffer mapping, or if pgoff points * past it, the mmio mapping. */ if (vma->vm_pgoff >= mmio_pgoff) { if (info->var.accel_flags) return -EINVAL; vma->vm_pgoff -= mmio_pgoff; start = info->fix.mmio_start; len = info->fix.mmio_len; } vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); vma->vm_page_prot = pgprot_framebuffer(vma->vm_page_prot, vma->vm_start, vma->vm_end, start); return vm_iomap_memory(vma, start, len); } EXPORT_SYMBOL(fb_io_mmap); MODULE_DESCRIPTION("Fbdev helpers for framebuffers in I/O memory"); MODULE_LICENSE("GPL"); |