gpu/drm, x86, PAT: io_mapping_create_wc and resource_size_t

io_mapping_create_wc should take a resource_size_t parameter in place of
unsigned long. With unsigned long, there will be no way to map greater than 4GB
address in i386/32 bit.

On x86, greater than 4GB addresses cannot be mapped on i386 without PAE. Return
error for such a case.

Patch also adds a structure for io_mapping, that saves the base, size and
type on HAVE_ATOMIC_IOMAP archs, that can be used to verify the offset on
io_mapping_map calls.

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, 3 insertions, 0 deletions

diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h
index c1f06289b14b..86af26091d6c 100644
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -23,6 +23,9 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 
+int
+is_io_mapping_possible(resource_size_t base, unsigned long size);
+
 void *
 iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);