mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-16 05:50:19 +00:00
7b71876980
boilerplate. SGI-PV: 913862 SGI-Modid: xfs-linux:xfs-kern:23903a Signed-off-by: Nathan Scott <nathans@sgi.com>
297 lines
7.5 KiB
C
297 lines
7.5 KiB
C
/*
|
|
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
|
|
* All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it would be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write the Free Software Foundation,
|
|
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
#include "xfs.h"
|
|
#include "xfs_bit.h"
|
|
#include "xfs_log.h"
|
|
#include "xfs_trans.h"
|
|
#include "xfs_buf_item.h"
|
|
|
|
/*
|
|
* 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
|
|
|
|
/*
|
|
* Count of bits set in byte, 0..8.
|
|
*/
|
|
static const char xfs_countbit[256] = {
|
|
0, 1, 1, 2, 1, 2, 2, 3, /* 00 .. 07 */
|
|
1, 2, 2, 3, 2, 3, 3, 4, /* 08 .. 0f */
|
|
1, 2, 2, 3, 2, 3, 3, 4, /* 10 .. 17 */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* 18 .. 1f */
|
|
1, 2, 2, 3, 2, 3, 3, 4, /* 20 .. 27 */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* 28 .. 2f */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* 30 .. 37 */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* 38 .. 3f */
|
|
1, 2, 2, 3, 2, 3, 3, 4, /* 40 .. 47 */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* 48 .. 4f */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* 50 .. 57 */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* 58 .. 5f */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* 60 .. 67 */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* 68 .. 6f */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* 70 .. 77 */
|
|
4, 5, 5, 6, 5, 6, 6, 7, /* 78 .. 7f */
|
|
1, 2, 2, 3, 2, 3, 3, 4, /* 80 .. 87 */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* 88 .. 8f */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* 90 .. 97 */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* 98 .. 9f */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* a0 .. a7 */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* a8 .. af */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* b0 .. b7 */
|
|
4, 5, 5, 6, 5, 6, 6, 7, /* b8 .. bf */
|
|
2, 3, 3, 4, 3, 4, 4, 5, /* c0 .. c7 */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* c8 .. cf */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* d0 .. d7 */
|
|
4, 5, 5, 6, 5, 6, 6, 7, /* d8 .. df */
|
|
3, 4, 4, 5, 4, 5, 5, 6, /* e0 .. e7 */
|
|
4, 5, 5, 6, 5, 6, 6, 7, /* e8 .. ef */
|
|
4, 5, 5, 6, 5, 6, 6, 7, /* f0 .. f7 */
|
|
5, 6, 6, 7, 6, 7, 7, 8, /* f8 .. ff */
|
|
};
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
|
|
/*
|
|
* Count the number of bits set in the bitmap starting with bit
|
|
* start_bit. Size is the size of the bitmap in words.
|
|
*
|
|
* Do the counting by mapping a byte value to the number of set
|
|
* bits for that value using the xfs_countbit array, i.e.
|
|
* xfs_countbit[0] == 0, xfs_countbit[1] == 1, xfs_countbit[2] == 1,
|
|
* xfs_countbit[3] == 2, etc.
|
|
*/
|
|
int
|
|
xfs_count_bits(uint *map, uint size, uint start_bit)
|
|
{
|
|
register int bits;
|
|
register unsigned char *bytep;
|
|
register unsigned char *end_map;
|
|
int byte_bit;
|
|
|
|
bits = 0;
|
|
end_map = (char*)(map + size);
|
|
bytep = (char*)(map + (start_bit & ~0x7));
|
|
byte_bit = start_bit & 0x7;
|
|
|
|
/*
|
|
* If the caller fell off the end of the map, return 0.
|
|
*/
|
|
if (bytep >= end_map) {
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* If start_bit is not byte aligned, then process the
|
|
* first byte separately.
|
|
*/
|
|
if (byte_bit != 0) {
|
|
/*
|
|
* Shift off the bits we don't want to look at,
|
|
* before indexing into xfs_countbit.
|
|
*/
|
|
bits += xfs_countbit[(*bytep >> byte_bit)];
|
|
bytep++;
|
|
}
|
|
|
|
/*
|
|
* Count the bits in each byte until the end of the bitmap.
|
|
*/
|
|
while (bytep < end_map) {
|
|
bits += xfs_countbit[*bytep];
|
|
bytep++;
|
|
}
|
|
|
|
return (bits);
|
|
}
|
|
|
|
/*
|
|
* Count the number of contiguous bits set in the bitmap starting with bit
|
|
* start_bit. Size is the size of the bitmap in words.
|
|
*/
|
|
int
|
|
xfs_contig_bits(uint *map, uint size, uint start_bit)
|
|
{
|
|
uint * p = ((unsigned int *) map) + (start_bit >> BIT_TO_WORD_SHIFT);
|
|
uint result = 0;
|
|
uint tmp;
|
|
|
|
size <<= BIT_TO_WORD_SHIFT;
|
|
|
|
ASSERT(start_bit < size);
|
|
size -= start_bit & ~(NBWORD - 1);
|
|
start_bit &= (NBWORD - 1);
|
|
if (start_bit) {
|
|
tmp = *p++;
|
|
/* set to one first offset bits prior to start */
|
|
tmp |= (~0U >> (NBWORD-start_bit));
|
|
if (tmp != ~0U)
|
|
goto found;
|
|
result += NBWORD;
|
|
size -= NBWORD;
|
|
}
|
|
while (size) {
|
|
if ((tmp = *p++) != ~0U)
|
|
goto found;
|
|
result += NBWORD;
|
|
size -= NBWORD;
|
|
}
|
|
return result - start_bit;
|
|
found:
|
|
return result + ffz(tmp) - start_bit;
|
|
}
|
|
|
|
/*
|
|
* This takes the bit number to start looking from and
|
|
* returns the next set bit from there. It returns -1
|
|
* if there are no more bits set or the start bit is
|
|
* beyond the end of the bitmap.
|
|
*
|
|
* Size is the number of words, not bytes, in the bitmap.
|
|
*/
|
|
int xfs_next_bit(uint *map, uint size, uint start_bit)
|
|
{
|
|
uint * p = ((unsigned int *) map) + (start_bit >> BIT_TO_WORD_SHIFT);
|
|
uint result = start_bit & ~(NBWORD - 1);
|
|
uint tmp;
|
|
|
|
size <<= BIT_TO_WORD_SHIFT;
|
|
|
|
if (start_bit >= size)
|
|
return -1;
|
|
size -= result;
|
|
start_bit &= (NBWORD - 1);
|
|
if (start_bit) {
|
|
tmp = *p++;
|
|
/* set to zero first offset bits prior to start */
|
|
tmp &= (~0U << start_bit);
|
|
if (tmp != 0U)
|
|
goto found;
|
|
result += NBWORD;
|
|
size -= NBWORD;
|
|
}
|
|
while (size) {
|
|
if ((tmp = *p++) != 0U)
|
|
goto found;
|
|
result += NBWORD;
|
|
size -= NBWORD;
|
|
}
|
|
return -1;
|
|
found:
|
|
return result + ffs(tmp) - 1;
|
|
}
|