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affs: use memweight() 

Use memweight() to count the total number of bits set in memory area.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Akinobu Mita 2012-07-30 14:41:00 -07:00 committed by Linus Torvalds
parent 8fb980e35b
commit 0121ad62c2
1 changed files with 2 additions and 26 deletions
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28
fs/affs/bitmap.c
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@ -10,30 +10,6 @@
#include <linux/slab.h>
#include "affs.h"
/* This is, of course, shamelessly stolen from fs/minix */
static const int nibblemap[] = { 0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4 };
static u32
affs_count_free_bits(u32 blocksize, const void *data)
{
const u32 *map;
u32 free;
u32 tmp;
map = data;
free = 0;
for (blocksize /= 4; blocksize > 0; blocksize--) {
tmp = *map++;
while (tmp) {
free += nibblemap[tmp & 0xf];
tmp >>= 4;
}
}
return free;
}
u32
affs_count_free_blocks(struct super_block *sb)
{
@ -317,7 +293,7 @@ int affs_init_bitmap(struct super_block *sb, int *flags)
goto out;
}
pr_debug("AFFS: read bitmap block %d: %d\n", blk, bm->bm_key);
bm->bm_free = affs_count_free_bits(sb->s_blocksize - 4, bh->b_data + 4);
bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);
/* Don't try read the extension if this is the last block,
* but we also need the right bm pointer below
@ -367,7 +343,7 @@ int affs_init_bitmap(struct super_block *sb, int *flags)
/* recalculate bitmap count for last block */
bm--;
bm->bm_free = affs_count_free_bits(sb->s_blocksize - 4, bh->b_data + 4);
bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);
out:
affs_brelse(bh);