vm: convert HPET mmap to vm_iomap_memory() helper

This is my example conversion of a few existing mmap users.  The HPET
case is simple, widely available, and easy to test (Clemens Ladisch sent
a trivial test-program for it).

Test-program-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index e3f9a99b8522e41dd2a4005142ea396838f26bbf..d784650d14f0d113c5d852e47d9dd676741e3b4f 100644 (file)
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -373,26 +373,14 @@ static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
        struct hpet_dev *devp;
        unsigned long addr;
 
-       if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
-               return -EINVAL;
-
        devp = file->private_data;
        addr = devp->hd_hpets->hp_hpet_phys;
 
        if (addr & (PAGE_SIZE - 1))
                return -ENOSYS;
 
-       vma->vm_flags |= VM_IO;
        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
-       if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
-                                       PAGE_SIZE, vma->vm_page_prot)) {
-               printk(KERN_ERR "%s: io_remap_pfn_range failed\n",
-                       __func__);
-               return -EAGAIN;
-       }
-
-       return 0;
+       return vm_iomap_memory(vma, addr, PAGE_SIZE);
 #else
        return -ENOSYS;
 #endif