From b3ea73c2d47633f9c1059e6832c7784c12c6aa75 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 19 Apr 2013 09:57:35 -0700
Subject: 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>
---
 drivers/video/fbmem.c | 39 ++++++++++++++-------------------------
 1 file changed, 14 insertions(+), 25 deletions(-)

(limited to 'drivers')

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index dc61c12ecf8c..0a494561f6eb 100644
--- 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
-- 
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