vm: convert fb_mmap to vm_iomap_memory() helper

commit fc9bbca8f650e5f738af8806317c0a041a48ae4a upstream.

This is my example conversion of a few existing mmap users.  The
fb_mmap() case is a good example because it is a bit more complicated
than some: fb_mmap() mmaps one of two different memory areas depending
on the page offset of the mmap (but happily there is never any mixing of
the two, so the helper function still works).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index dc61c12ecf8ca516e7910fc5156e81e9701bb788..0a494561f6ebc6a8078b271aed00f6e4361cf470 100644 (file)
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1373,15 +1373,12 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
 {
        struct fb_info *info = file_fb_info(file);
        struct fb_ops *fb;
-       unsigned long off;
+       unsigned long mmio_pgoff;
        unsigned long start;
        u32 len;
 
        if (!info)
                return -ENODEV;
-       if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
-               return -EINVAL;
-       off = vma->vm_pgoff << PAGE_SHIFT;
        fb = info->fbops;
        if (!fb)
                return -ENODEV;
@@ -1393,32 +1390,24 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
                return res;
        }
 
-       /* frame buffer memory */
+       /*
+        * Ugh. This can be either the frame buffer mapping, or
+        * if pgoff points past it, the mmio mapping.
+        */
        start = info->fix.smem_start;
-       len = PAGE_ALIGN((start & ~PAGE_MASK) + info->fix.smem_len);
-       if (off >= len) {
-               /* memory mapped io */
-               off -= len;
-               if (info->var.accel_flags) {
-                       mutex_unlock(&info->mm_lock);
-                       return -EINVAL;
-               }
+       len = info->fix.smem_len;
+       mmio_pgoff = PAGE_ALIGN((start & ~PAGE_MASK) + len) >> PAGE_SHIFT;
+       if (vma->vm_pgoff >= mmio_pgoff) {
+               vma->vm_pgoff -= mmio_pgoff;
                start = info->fix.mmio_start;
-               len = PAGE_ALIGN((start & ~PAGE_MASK) + info->fix.mmio_len);
+               len = info->fix.mmio_len;
        }
        mutex_unlock(&info->mm_lock);
-       start &= PAGE_MASK;
-       if ((vma->vm_end - vma->vm_start + off) > len)
-               return -EINVAL;
-       off += start;
-       vma->vm_pgoff = off >> PAGE_SHIFT;
-       /* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by io_remap_pfn_range()*/
+
        vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
-       fb_pgprotect(file, vma, off);
-       if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
-                            vma->vm_end - vma->vm_start, vma->vm_page_prot))
-               return -EAGAIN;
-       return 0;
+       fb_pgprotect(file, vma, start);
+
+       return vm_iomap_memory(vma, start, len);
 }
 
 static int