Commit 8f235d1a authored by Chen Gang's avatar Chen Gang Committed by Linus Torvalds

mm: add PHYS_PFN, use it in __phys_to_pfn()

__phys_to_pfn and __pfn_to_phys are symmetric, PHYS_PFN and PFN_PHYS are
semmetric:

 - y = (phys_addr_t)x << PAGE_SHIFT

 - y >> PAGE_SHIFT = (phys_add_t)x

 - (unsigned long)(y >> PAGE_SHIFT) = x

[akpm@linux-foundation.org: use macro arg name `x']
[arnd@arndb.de: include linux/pfn.h for PHYS_PFN definition]
Signed-off-by: default avatarChen Gang <gang.chen.5i5j@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3aa23851
#ifndef __ASM_MEMORY_MODEL_H
#define __ASM_MEMORY_MODEL_H
#include <linux/pfn.h>
#ifndef __ASSEMBLY__
#if defined(CONFIG_FLATMEM)
......@@ -72,7 +74,7 @@
/*
* Convert a physical address to a Page Frame Number and back
*/
#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >> PAGE_SHIFT))
#define __phys_to_pfn(paddr) PHYS_PFN(paddr)
#define __pfn_to_phys(pfn) PFN_PHYS(pfn)
#define page_to_pfn __page_to_pfn
......
......@@ -9,5 +9,6 @@
#define PFN_UP(x) (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
#define PFN_DOWN(x) ((x) >> PAGE_SHIFT)
#define PFN_PHYS(x) ((phys_addr_t)(x) << PAGE_SHIFT)
#define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT))
#endif
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