[PATCH 1 of 8] x86: define PTE_MASK in a universally useful way

Jeremy Fitzhardinge
2008-05-20T09:07:27Z

Define PTE_MASK so that it contains a meaningful value for all x86
pagetable configurations. Previously it was defined as a "long" which
means that it was too short to cover a 32-bit PAE pte entry.

It is now defined as a pteval_t, which is an integer type long enough
to contain a full pte (or pmd, pud, pgd).

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
---
include/asm-x86/page.h | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/include/asm-x86/page.h b/include/asm-x86/page.h
--- a/include/asm-x86/page.h
+++ b/include/asm-x86/page.h
@@ -10,8 +10,13 @@

#ifdef __KERNEL__

-#define PHYSICAL_PAGE_MASK (PAGE_MASK & __PHYSICAL_MASK)
-#define PTE_MASK (_AT(long, PHYSICAL_PAGE_MASK))
+/* Cast PAGE_MASK to a signed type so that it is sign-extended if
+ virtual addresses are 32-bits but physical addresses are larger
+ (ie, 32-bit PAE). */
+#define PHYSICAL_PAGE_MASK (((signed long)PAGE_MASK) & __PHYSICAL_MASK)
+
+/* PTE_MASK extracts the PFN from a (pte|pmd|pud|pgd)val_t */
+#define PTE_MASK ((pteval_t)PHYSICAL_PAGE_MASK)

#define PMD_PAGE_SIZE (_AC(1, UL) << PMD_SHIFT)
#define PMD_PAGE_MASK (~(PMD_PAGE_SIZE-1))
@@ -24,8 +29,8 @@
/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)

-#define __PHYSICAL_MASK _AT(phys_addr_t, (_AC(1,ULL) << __PHYSICAL_MASK_SHIFT) - 1)
-#define __VIRTUAL_MASK ((_AC(1,UL) << __VIRTUAL_MASK_SHIFT) - 1)
+#define __PHYSICAL_MASK ((((phys_addr_t)1) << __PHYSICAL_MASK_SHIFT) - 1)
+#define __VIRTUAL_MASK ((1UL << __VIRTUAL_MASK_SHIFT) - 1)

#ifndef __ASSEMBLY__
#include <linux/types.h>