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| author |   Will Deacon <will.deacon@arm.com> | 2013-12-12 17:40:21 +0000 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2013-12-12 10:39:01 -0800 |
| commit | a5c21dcefa1c3d759457a604b3cfc4af29c8713f (patch) | |
| tree | 6832dfcb836f8d5043ba70f17a0ea9c2c428bc4d /include | |
| parent | Merge tag 'iommu-fixes-for-v3.13-rc4' of git://github.com/awilliam/linux-vfio (diff) | |
| download | linux-dev-a5c21dcefa1c3d759457a604b3cfc4af29c8713f.tar.xz linux-dev-a5c21dcefa1c3d759457a604b3cfc4af29c8713f.zip | |
dcache: allow word-at-a-time name hashing with big-endian CPUs
When explicitly hashing the end of a string with the word-at-a-time
interface, we have to be careful which end of the word we pick up.
On big-endian CPUs, the upper-bits will contain the data we're after, so
ensure we generate our masks accordingly (and avoid hashing whatever
random junk may have been sitting after the string).
This patch adds a new dcache helper, bytemask_from_count, which creates
a mask appropriate for the CPU endianness.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/dcache.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 57e87e749a48..bf72e9ac6de0 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -29,8 +29,10 @@ struct vfsmount; /* The hash is always the low bits of hash_len */ #ifdef __LITTLE_ENDIAN #define HASH_LEN_DECLARE u32 hash; u32 len; + #define bytemask_from_count(cnt) (~(~0ul << (cnt)*8)) #else #define HASH_LEN_DECLARE u32 len; u32 hash; + #define bytemask_from_count(cnt) (~(~0ul >> (cnt)*8)) #endif /* |