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mtd: mtdchar: fix mmap for MTD RAM/ROM char devices

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For no-mmu systems mmap() on RAM/ROM devices already works
but for systems with mmu it probably was not tested and
doesn't work.

This patch allows using mmap() on MTD RAM/ROM devices on systems
with MMU. It has been tested on mpc5121e based platform with
MR0A16A MRAM device attached over LocalBus.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Anatolij Gustschin 2010-06-15 09:30:15 +02:00 committed by David Woodhouse
parent 68640c2a41
commit dd02b67d5e
1 changed files with 27 additions and 1 deletions
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28
drivers/mtd/mtdchar.c
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@ -18,6 +18,7 @@
#include <linux/mount.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/compatmac.h>
#include <asm/uaccess.h>
@ -955,9 +956,34 @@ static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
#ifdef CONFIG_MMU
struct mtd_file_info *mfi = file->private_data;
struct mtd_info *mtd = mfi->mtd;
struct map_info *map = mtd->priv;
unsigned long start;
unsigned long off;
u32 len;
if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
off = vma->vm_pgoff << PAGE_SHIFT;
start = map->phys;
len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
start &= PAGE_MASK;
if ((vma->vm_end - vma->vm_start + off) > len)
return -EINVAL;
off += start;
vma->vm_pgoff = off >> PAGE_SHIFT;
vma->vm_flags |= VM_IO | VM_RESERVED;
#ifdef pgprot_noncached
if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
#endif
if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
vma->vm_end - vma->vm_start,
vma->vm_page_prot))
return -EAGAIN;
if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
return 0;
}
return -ENOSYS;
#else
return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;