x86, pat: Add PAT reserve free to io_mapping* APIs

io_mapping_* interfaces were added, mainly for graphics drivers.
Make this interface go through the PAT reserve/free, instead of
hardcoding WC mapping. This makes sure that there are no
aliases due to unconditional WC setting.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Venkatesh Pallipadi
2009-07-10 09:57:35 -07:00
committed by H. Peter Anvin
parent 9fd126bc74
commit 9e36fda0b3
3 changed files with 43 additions and 10 deletions

View File

@@ -21,7 +21,7 @@
#include <linux/module.h>
#include <linux/highmem.h>
int is_io_mapping_possible(resource_size_t base, unsigned long size)
static int is_io_mapping_possible(resource_size_t base, unsigned long size)
{
#if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT)
/* There is no way to map greater than 1 << 32 address without PAE */
@@ -30,7 +30,30 @@ int is_io_mapping_possible(resource_size_t base, unsigned long size)
#endif
return 1;
}
EXPORT_SYMBOL_GPL(is_io_mapping_possible);
int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot)
{
unsigned long flag = _PAGE_CACHE_WC;
int ret;
if (!is_io_mapping_possible(base, size))
return -EINVAL;
ret = io_reserve_memtype(base, base + size, &flag);
if (ret)
return ret;
*prot = __pgprot(__PAGE_KERNEL | flag);
return 0;
}
EXPORT_SYMBOL_GPL(iomap_create_wc);
void
iomap_free(resource_size_t base, unsigned long size)
{
io_free_memtype(base, base + size);
}
EXPORT_SYMBOL_GPL(iomap_free);
void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
{