mm: make lowmem_page_address() use PFN_PHYS() for improved portability
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@tilera.com>
Cc: Barry Song <21cnbao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 963f908..b969efb 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;
@@ -595,7 +596,7 @@
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)