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

This reverts commit 17581ad812a9abb0182260374ef2e52d4a808a64.

Sitsofe Wheeler reported that /dev/dri/card0 is MIA on his EeePC 900
and bisected it to this commit.

Graphics card is an i915 in an EeePC 900:

 00:02.0 VGA compatible controller [0300]:
   Intel Corporation Mobile 915GM/GMS/910GML
     Express Graphics Controller [8086:2592] (rev 04)

( Most likely the ioremap() of the driver failed and hence the card
  did not initialize. )

Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Bisected-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 4 deletions

diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h
index f1ed66c43787..cbc2f0cd631b 100644
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -49,9 +49,8 @@ static inline struct io_mapping *
 io_mapping_create_wc(resource_size_t base, unsigned long size)
 {
         struct io_mapping *iomap;
-        pgprot_t prot;
 
-        if (!reserve_io_memtype_wc(base, size, &prot))
+        if (!is_io_mapping_possible(base, size))
                 return NULL;
 
         iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
@@ -60,14 +59,13 @@ io_mapping_create_wc(resource_size_t base, unsigned long size)
 
         iomap->base = base;
         iomap->size = size;
-        iomap->prot = prot;
+        iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL));
         return iomap;
 }
 
 static inline void
 io_mapping_free(struct io_mapping *mapping)
 {
-        free_io_memtype(mapping->base, mapping->size);
         kfree(mapping);
 }