2005-12-13 23:56:18

by Bjorn Helgaas

Subject: [patch 1/2] /dev/mem __HAVE_PHYS_MEM_ACCESS_PROT tidy-up

Tidy up __HAVE_PHYS_MEM_ACCESS_PROT usage to make mmap_mem() easier to read.

Signed-off-by: Bjorn Helgaas <[email protected]>

drivers/char/mem.c | 23 ++++++++++++++---------
1 files changed, 14 insertions(+), 9 deletions(-)

Index: work5/drivers/char/mem.c
===================================================================
--- work5.orig/drivers/char/mem.c 2005-12-09 15:52:28.000000000 -0700
+++ work5/drivers/char/mem.c 2005-12-09 16:17:50.000000000 -0700
@@ -228,20 +228,25 @@
return written;
}

+#ifndef __HAVE_PHYS_MEM_ACCESS_PROT
+static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot)
+{
+#ifdef pgprot_noncached
+ unsigned long offset = pfn << PAGE_SHIFT;
+
+ if (uncached_access(file, offset))
+ return pgprot_noncached(vma_prot);
+#endif
+ return vma_prot;
+}
+#endif
+
static int mmap_mem(struct file * file, struct vm_area_struct * vma)
{
-#if defined(__HAVE_PHYS_MEM_ACCESS_PROT)
vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
-#elif defined(pgprot_noncached)
- unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
- int uncached;
-
- uncached = uncached_access(file, offset);
- if (uncached)
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-#endif

/* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
if (remap_pfn_range(vma,

2005-12-14 00:06:49

by David Miller

Subject: Re: [patch 1/2] /dev/mem __HAVE_PHYS_MEM_ACCESS_PROT tidy-up

From: Bjorn Helgaas <[email protected]>
Date: Tue, 13 Dec 2005 16:56:11 -0700

> Tidy up __HAVE_PHYS_MEM_ACCESS_PROT usage to make mmap_mem() easier to read.
>
> Signed-off-by: Bjorn Helgaas <[email protected]>

It would be _really_ easy to read if the default implementation
lived in some asm-generic/foo.h header file :-)