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

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>

1 files changed, 4 insertions, 2 deletions

diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h
index cbc2f0cd631b..f1ed66c43787 100644
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -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);
 }