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gpu/drm, x86, PAT: PAT support for io_mapping_*

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Make io_mapping_create_wc and io_mapping_free go through PAT to make sure
that there are no memory type aliases.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Venkatesh Pallipadi 2009-02-24 17:35:14 -08:00 committed by Ingo Molnar
parent 7880f74645
commit 17581ad812
3 changed files with 48 additions and 5 deletions
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5
arch/x86/include/asm/iomap.h
View file

@ -24,7 +24,10 @@
#include <asm/tlbflush.h>
int
is_io_mapping_possible(resource_size_t base, unsigned long size);
reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot);
void
free_io_memtype(u64 base, unsigned long size);
void *
iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);

42
arch/x86/mm/iomap_32.c
View file

@ -21,13 +21,13 @@
#include <linux/module.h>
#ifdef CONFIG_X86_PAE
int
static int
is_io_mapping_possible(resource_size_t base, unsigned long size)
{
return 1;
}
#else
int
static int
is_io_mapping_possible(resource_size_t base, unsigned long size)
{
/* There is no way to map greater than 1 << 32 address without PAE */
@ -38,6 +38,44 @@ is_io_mapping_possible(resource_size_t base, unsigned long size)
}
#endif
int
reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot)
{
unsigned long ret_flag;
if (!is_io_mapping_possible(base, size))
goto out_err;
if (!pat_enabled) {
*prot = pgprot_noncached(PAGE_KERNEL);
return 0;
}
if (reserve_memtype(base, base + size, _PAGE_CACHE_WC, &ret_flag))
goto out_err;
if (ret_flag == _PAGE_CACHE_WB)
goto out_free;
if (kernel_map_sync_memtype(base, size, ret_flag))
goto out_free;
*prot = __pgprot(__PAGE_KERNEL | ret_flag);
return 0;
out_free:
free_memtype(base, base + size);
out_err:
return -EINVAL;
}
void
free_io_memtype(u64 base, unsigned long size)
{
if (pat_enabled)
free_memtype(base, base + size);
}
/* Map 'pfn' using fixed map 'type' and protections 'prot'
*/
void *

6
include/linux/io-mapping.h
View file

@ -49,8 +49,9 @@ static inline struct io_mapping *
io_mapping_create_wc(resource_size_t base, unsigned long size)
{
struct io_mapping *iomap;
pgprot_t prot;
if (!is_io_mapping_possible(base, size))
if (!reserve_io_memtype_wc(base, size, &prot))
return NULL;
iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
@ -59,13 +60,14 @@ io_mapping_create_wc(resource_size_t base, unsigned long size)
iomap->base = base;
iomap->size = size;
iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL));
iomap->prot = prot;
return iomap;
}
static inline void
io_mapping_free(struct io_mapping *mapping)
{
free_io_memtype(mapping->base, mapping->size);
kfree(mapping);
}