x86: PAT avoid aliasing in /dev/mem read/write

Add xlate and unxlate around /dev/mem read/write. This sets up the mapping
that can be used for /dev/mem read and write without aliasing worries.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 8 insertions, 12 deletions

diff --git a/include/asm-x86/io.h b/include/asm-x86/io.h
index 7b292d386713..d5b11f60dbd0 100644
--- a/include/asm-x86/io.h
+++ b/include/asm-x86/io.h
@@ -1,3 +1,6 @@
+#ifndef _ASM_X86_IO_H
+#define _ASM_X86_IO_H
+
 #define ARCH_HAS_IOREMAP_WC
 
 #ifdef CONFIG_X86_32
@@ -5,7 +8,12 @@
 #else
 # include "io_64.h"
 #endif
+
+extern void *xlate_dev_mem_ptr(unsigned long phys);
+extern void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
+
 extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
                                 unsigned long prot_val);
 extern void __iomem *ioremap_wc(unsigned long offset, unsigned long size);
 
+#endif /* _ASM_X86_IO_H */
diff --git a/include/asm-x86/io_32.h b/include/asm-x86/io_32.h
index 509045f5fda2..6e73467a4fb1 100644
--- a/include/asm-x86/io_32.h
+++ b/include/asm-x86/io_32.h
@@ -49,12 +49,6 @@
 #include <linux/vmalloc.h>
 
 /*
- * Convert a physical pointer to a virtual kernel pointer for /dev/mem
- * access
- */
-#define xlate_dev_mem_ptr(p)    __va(p)
-
-/*
  * Convert a virtual cached pointer to an uncached pointer
  */
 #define xlate_dev_kmem_ptr(p)   p
diff --git a/include/asm-x86/io_64.h b/include/asm-x86/io_64.h
index c2f5eef47b88..0930bedf9e4d 100644
--- a/include/asm-x86/io_64.h
+++ b/include/asm-x86/io_64.h
@@ -308,12 +308,6 @@ extern int iommu_bio_merge;
 #define BIO_VMERGE_BOUNDARY iommu_bio_merge
 
 /*
- * Convert a physical pointer to a virtual kernel pointer for /dev/mem
- * access
- */
-#define xlate_dev_mem_ptr(p)    __va(p)
-
-/*
  * Convert a virtual cached pointer to an uncached pointer
  */
 #define xlate_dev_kmem_ptr(p)   p