lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[XFS] Use the generic bitops rather than implementing them ourselves.

Browse Source 
This keeps xfs_lowbit64 as it was since there aren't good generic helpers
there ... Patch inspired by Andi Kleen.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31472a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
This commit is contained in:
David Chinner
2008-08-13 15:41:12 +10:00
committed by Lachlan McIlroy
parent 10fec20ef5
commit 79071eb0b2
3 changed files with 38 additions and 120 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
fs/xfs/xfs_bit.h
View File

@ -47,13 +47,39 @@ static inline __uint64_t xfs_mask64lo(int n)
}
/* Get high bit set out of 32-bit argument, -1 if none set */
extern int xfs_highbit32(__uint32_t v);
/* Get low bit set out of 64-bit argument, -1 if none set */
extern int xfs_lowbit64(__uint64_t v);
static inline int xfs_highbit32(__uint32_t v)
{
return fls(v) - 1;
}
/* Get high bit set out of 64-bit argument, -1 if none set */
extern int xfs_highbit64(__uint64_t);
static inline int xfs_highbit64(__uint64_t v)
{
return fls64(v) - 1;
}
/* Get low bit set out of 32-bit argument, -1 if none set */
static inline int xfs_lowbit32(__uint32_t v)
{
unsigned long t = v;
return (v) ? find_first_bit(&t, 32) : -1;
}
/* Get low bit set out of 64-bit argument, -1 if none set */
static inline int xfs_lowbit64(__uint64_t v)
{
__uint32_t w = (__uint32_t)v;
int n = 0;
if (w) { /* lower bits */
n = ffs(w);
} else { /* upper bits */
w = (__uint32_t)(v >> 32);
if (w && (n = ffs(w)))
n += 32;
}
return n - 1;
}
/* Return whether bitmap is empty (1 == empty) */
extern int xfs_bitmap_empty(uint *map, uint size);