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

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Patch inspired by Andi Kleen.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30000a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
This commit is contained in:
David Chinner 2007-11-23 16:27:59 +11:00 committed by Lachlan McIlroy
parent c319b58b13
commit a69b176df2
3 changed files with 29 additions and 120 deletions
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103
fs/xfs/xfs_bit.c
View file

@ -25,109 +25,6 @@
* XFS bit manipulation routines, used in non-realtime code.
*/
#ifndef HAVE_ARCH_HIGHBIT
/*
* Index of high bit number in byte, -1 for none set, 0..7 otherwise.
*/
static const char xfs_highbit[256] = {
-1, 0, 1, 1, 2, 2, 2, 2, /* 00 .. 07 */
3, 3, 3, 3, 3, 3, 3, 3, /* 08 .. 0f */
4, 4, 4, 4, 4, 4, 4, 4, /* 10 .. 17 */
4, 4, 4, 4, 4, 4, 4, 4, /* 18 .. 1f */
5, 5, 5, 5, 5, 5, 5, 5, /* 20 .. 27 */
5, 5, 5, 5, 5, 5, 5, 5, /* 28 .. 2f */
5, 5, 5, 5, 5, 5, 5, 5, /* 30 .. 37 */
5, 5, 5, 5, 5, 5, 5, 5, /* 38 .. 3f */
6, 6, 6, 6, 6, 6, 6, 6, /* 40 .. 47 */
6, 6, 6, 6, 6, 6, 6, 6, /* 48 .. 4f */
6, 6, 6, 6, 6, 6, 6, 6, /* 50 .. 57 */
6, 6, 6, 6, 6, 6, 6, 6, /* 58 .. 5f */
6, 6, 6, 6, 6, 6, 6, 6, /* 60 .. 67 */
6, 6, 6, 6, 6, 6, 6, 6, /* 68 .. 6f */
6, 6, 6, 6, 6, 6, 6, 6, /* 70 .. 77 */
6, 6, 6, 6, 6, 6, 6, 6, /* 78 .. 7f */
7, 7, 7, 7, 7, 7, 7, 7, /* 80 .. 87 */
7, 7, 7, 7, 7, 7, 7, 7, /* 88 .. 8f */
7, 7, 7, 7, 7, 7, 7, 7, /* 90 .. 97 */
7, 7, 7, 7, 7, 7, 7, 7, /* 98 .. 9f */
7, 7, 7, 7, 7, 7, 7, 7, /* a0 .. a7 */
7, 7, 7, 7, 7, 7, 7, 7, /* a8 .. af */
7, 7, 7, 7, 7, 7, 7, 7, /* b0 .. b7 */
7, 7, 7, 7, 7, 7, 7, 7, /* b8 .. bf */
7, 7, 7, 7, 7, 7, 7, 7, /* c0 .. c7 */
7, 7, 7, 7, 7, 7, 7, 7, /* c8 .. cf */
7, 7, 7, 7, 7, 7, 7, 7, /* d0 .. d7 */
7, 7, 7, 7, 7, 7, 7, 7, /* d8 .. df */
7, 7, 7, 7, 7, 7, 7, 7, /* e0 .. e7 */
7, 7, 7, 7, 7, 7, 7, 7, /* e8 .. ef */
7, 7, 7, 7, 7, 7, 7, 7, /* f0 .. f7 */
7, 7, 7, 7, 7, 7, 7, 7, /* f8 .. ff */
};
#endif
/*
* xfs_highbit32: get high bit set out of 32-bit argument, -1 if none set.
*/
inline int
xfs_highbit32(
__uint32_t v)
{
#ifdef HAVE_ARCH_HIGHBIT
return highbit32(v);
#else
int i;
if (v & 0xffff0000)
if (v & 0xff000000)
i = 24;
else
i = 16;
else if (v & 0x0000ffff)
if (v & 0x0000ff00)
i = 8;
else
i = 0;
else
return -1;
return i + xfs_highbit[(v >> i) & 0xff];
#endif
}
/*
* xfs_lowbit64: get low bit set out of 64-bit argument, -1 if none set.
*/
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;
}
/*
* xfs_highbit64: get high bit set out of 64-bit argument, -1 if none set.
*/
int
xfs_highbit64(
__uint64_t v)
{
__uint32_t h = (__uint32_t)(v >> 32);
if (h)
return xfs_highbit32(h) + 32;
return xfs_highbit32((__uint32_t)v);
}
/*
* Return whether bitmap is empty.
* Size is number of words in the bitmap, which is padded to word boundary

27
fs/xfs/xfs_bit.h
View file

@ -47,13 +47,30 @@ 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)
{
unsigned long t = v;
return (v) ? find_first_bit(&t, 64) : -1;
}
/* Return whether bitmap is empty (1 == empty) */
extern int xfs_bitmap_empty(uint *map, uint size);

19
fs/xfs/xfs_rtalloc.c
View file

@ -72,18 +72,6 @@ STATIC int xfs_rtmodify_summary(xfs_mount_t *, xfs_trans_t *, int,
* Internal functions.
*/
/*
* xfs_lowbit32: get low bit set out of 32-bit argument, -1 if none set.
*/
STATIC int
xfs_lowbit32(
__uint32_t v)
{
if (v)
return ffs(v) - 1;
return -1;
}
/*
* Allocate space to the bitmap or summary file, and zero it, for growfs.
*/
@ -444,6 +432,7 @@ xfs_rtallocate_extent_near(
}
bbno = XFS_BITTOBLOCK(mp, bno);
i = 0;
ASSERT(minlen != 0);
log2len = xfs_highbit32(minlen);
/*
* Loop over all bitmap blocks (bbno + i is current block).
@ -612,6 +601,8 @@ xfs_rtallocate_extent_size(
xfs_suminfo_t sum; /* summary information for extents */
ASSERT(minlen % prod == 0 && maxlen % prod == 0);
ASSERT(maxlen != 0);
/*
* Loop over all the levels starting with maxlen.
* At each level, look at all the bitmap blocks, to see if there
@ -669,6 +660,9 @@ xfs_rtallocate_extent_size(
*rtblock = NULLRTBLOCK;
return 0;
}
ASSERT(minlen != 0);
ASSERT(maxlen != 0);
/*
* Loop over sizes, from maxlen down to minlen.
* This time, when we do the allocations, allow smaller ones
@ -1954,6 +1948,7 @@ xfs_growfs_rt(
nsbp->sb_blocksize * nsbp->sb_rextsize);
nsbp->sb_rextents = nsbp->sb_rblocks;
do_div(nsbp->sb_rextents, nsbp->sb_rextsize);
ASSERT(nsbp->sb_rextents != 0);
nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents);
nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
nrsumsize =