[PATCH] generic: make lowmem_page_address() use PFN_PHYS() for improvedportability

From: Chris Metcalf
Date: Thu May 20 2010 - 15:12:24 EST


This ensures that platforms with lowmem PAs above 32 bits work
correctly by avoiding truncating the PA during a left shift.

Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
---
include/linux/mm.h | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fb19bb9..33bedcf 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -13,6 +13,7 @@
#include <linux/debug_locks.h>
#include <linux/mm_types.h>
#include <linux/range.h>
+#include <linux/pfn.h>

struct mempolicy;
struct anon_vma;
@@ -591,7 +592,7 @@ static inline void set_page_links(struct page *page,
enum zone_type zone,

static __always_inline void *lowmem_page_address(struct page *page)
{
- return __va(page_to_pfn(page) << PAGE_SHIFT);
+ return __va(PFN_PHYS(page_to_pfn(page)));
}

#if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/