diff options
author | Chen Gang <xili_gchen_5257@hotmail.com> | 2016-01-14 15:18:33 -0800 |
---|---|---|
committer | Mark Salyzyn <salyzyn@google.com> | 2017-03-30 09:09:03 -0700 |
commit | 510b819279cb6d4b803059ef66ec1bc05e187a04 (patch) | |
tree | 2aed9acd2dbd1eac765e977676e94acb18da8090 /include/linux/pfn.h | |
parent | e1feee06592832d3b9f51e0649b18d34f0a5e16e (diff) |
UPSTREAM: mm: add PHYS_PFN, use it in __phys_to_pfn()
(cherry pick from commit 8f235d1a3eb7198affe7cadf676a10afb8a46a1a)
__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: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 20045882
Bug: 19198045
Change-Id: If968d2246b381b9e5d6446e9d6d9fa45bb718e91
Diffstat (limited to 'include/linux/pfn.h')
-rw-r--r-- | include/linux/pfn.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/pfn.h b/include/linux/pfn.h index 7646637221f3..97f3e88aead4 100644 --- a/include/linux/pfn.h +++ b/include/linux/pfn.h @@ -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 |