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 babbb07f030235282d8e19955fd7b936c6a73a45..0a22808229d66e59aee7f082a91fa1cd54ba7ead 100644 (file)
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1350,15 +1350,12 @@ 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;
@@ -1370,33 +1367,24 @@ 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;
-       /* This is an IO map - tell maydump to skip this VMA */
-       vma->vm_flags |= VM_IO | VM_RESERVED;
+
        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