x86: fix /dev/mem compatibility under PAT

Add ioremap_default(), which gives a sane mapping without worrying about
type conflicts.

Use it in /dev/mem read in place of ioremap(), as with ioremap(),
any mapping of the region (other than UC_MINUS) will cause a conflict
and failure of /dev/mem read.

Should address the vbetest failure reported at:

  http://bugzilla.kernel.org/show_bug.cgi?id=11057

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Venkatesh Pallipadi 2008-07-10 10:09:59 +02:00 committed by Ingo Molnar
parent a1716d508a
commit a361ee5cb8

View File

@ -300,6 +300,29 @@ void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
}
EXPORT_SYMBOL(ioremap_cache);
static void __iomem *ioremap_default(resource_size_t phys_addr,
unsigned long size)
{
unsigned long flags;
void *ret;
int err;
/*
* - WB for WB-able memory and no other conflicting mappings
* - UC_MINUS for non-WB-able memory with no other conflicting mappings
* - Inherit from confliting mappings otherwise
*/
err = reserve_memtype(phys_addr, phys_addr + size, -1, &flags);
if (err < 0)
return NULL;
ret = (void *) __ioremap_caller(phys_addr, size, flags,
__builtin_return_address(0));
free_memtype(phys_addr, phys_addr + size);
return (void __iomem *)ret;
}
/**
* iounmap - Free a IO remapping
* @addr: virtual address from ioremap_*
@ -365,7 +388,7 @@ void *xlate_dev_mem_ptr(unsigned long phys)
if (page_is_ram(start >> PAGE_SHIFT))
return __va(phys);
addr = (void *)ioremap(start, PAGE_SIZE);
addr = (void *)ioremap_default(start, PAGE_SIZE);
if (addr)
addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));