mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-13 14:04:05 +08:00
1470afefc3
Equivalent of for_each_cpu_and, except it ORs the two masks together so it iterates all the CPUs present in either mask. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
271 lines
7.2 KiB
C
271 lines
7.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* bit search implementation
|
|
*
|
|
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* Copyright (C) 2008 IBM Corporation
|
|
* 'find_last_bit' is written by Rusty Russell <rusty@rustcorp.com.au>
|
|
* (Inspired by David Howell's find_next_bit implementation)
|
|
*
|
|
* Rewritten by Yury Norov <yury.norov@gmail.com> to decrease
|
|
* size and improve performance, 2015.
|
|
*/
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/bitmap.h>
|
|
#include <linux/export.h>
|
|
#include <linux/math.h>
|
|
#include <linux/minmax.h>
|
|
#include <linux/swab.h>
|
|
|
|
/*
|
|
* Common helper for find_bit() function family
|
|
* @FETCH: The expression that fetches and pre-processes each word of bitmap(s)
|
|
* @MUNGE: The expression that post-processes a word containing found bit (may be empty)
|
|
* @size: The bitmap size in bits
|
|
*/
|
|
#define FIND_FIRST_BIT(FETCH, MUNGE, size) \
|
|
({ \
|
|
unsigned long idx, val, sz = (size); \
|
|
\
|
|
for (idx = 0; idx * BITS_PER_LONG < sz; idx++) { \
|
|
val = (FETCH); \
|
|
if (val) { \
|
|
sz = min(idx * BITS_PER_LONG + __ffs(MUNGE(val)), sz); \
|
|
break; \
|
|
} \
|
|
} \
|
|
\
|
|
sz; \
|
|
})
|
|
|
|
/*
|
|
* Common helper for find_next_bit() function family
|
|
* @FETCH: The expression that fetches and pre-processes each word of bitmap(s)
|
|
* @MUNGE: The expression that post-processes a word containing found bit (may be empty)
|
|
* @size: The bitmap size in bits
|
|
* @start: The bitnumber to start searching at
|
|
*/
|
|
#define FIND_NEXT_BIT(FETCH, MUNGE, size, start) \
|
|
({ \
|
|
unsigned long mask, idx, tmp, sz = (size), __start = (start); \
|
|
\
|
|
if (unlikely(__start >= sz)) \
|
|
goto out; \
|
|
\
|
|
mask = MUNGE(BITMAP_FIRST_WORD_MASK(__start)); \
|
|
idx = __start / BITS_PER_LONG; \
|
|
\
|
|
for (tmp = (FETCH) & mask; !tmp; tmp = (FETCH)) { \
|
|
if ((idx + 1) * BITS_PER_LONG >= sz) \
|
|
goto out; \
|
|
idx++; \
|
|
} \
|
|
\
|
|
sz = min(idx * BITS_PER_LONG + __ffs(MUNGE(tmp)), sz); \
|
|
out: \
|
|
sz; \
|
|
})
|
|
|
|
#define FIND_NTH_BIT(FETCH, size, num) \
|
|
({ \
|
|
unsigned long sz = (size), nr = (num), idx, w, tmp; \
|
|
\
|
|
for (idx = 0; (idx + 1) * BITS_PER_LONG <= sz; idx++) { \
|
|
if (idx * BITS_PER_LONG + nr >= sz) \
|
|
goto out; \
|
|
\
|
|
tmp = (FETCH); \
|
|
w = hweight_long(tmp); \
|
|
if (w > nr) \
|
|
goto found; \
|
|
\
|
|
nr -= w; \
|
|
} \
|
|
\
|
|
if (sz % BITS_PER_LONG) \
|
|
tmp = (FETCH) & BITMAP_LAST_WORD_MASK(sz); \
|
|
found: \
|
|
sz = min(idx * BITS_PER_LONG + fns(tmp, nr), sz); \
|
|
out: \
|
|
sz; \
|
|
})
|
|
|
|
#ifndef find_first_bit
|
|
/*
|
|
* Find the first set bit in a memory region.
|
|
*/
|
|
unsigned long _find_first_bit(const unsigned long *addr, unsigned long size)
|
|
{
|
|
return FIND_FIRST_BIT(addr[idx], /* nop */, size);
|
|
}
|
|
EXPORT_SYMBOL(_find_first_bit);
|
|
#endif
|
|
|
|
#ifndef find_first_and_bit
|
|
/*
|
|
* Find the first set bit in two memory regions.
|
|
*/
|
|
unsigned long _find_first_and_bit(const unsigned long *addr1,
|
|
const unsigned long *addr2,
|
|
unsigned long size)
|
|
{
|
|
return FIND_FIRST_BIT(addr1[idx] & addr2[idx], /* nop */, size);
|
|
}
|
|
EXPORT_SYMBOL(_find_first_and_bit);
|
|
#endif
|
|
|
|
#ifndef find_first_zero_bit
|
|
/*
|
|
* Find the first cleared bit in a memory region.
|
|
*/
|
|
unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size)
|
|
{
|
|
return FIND_FIRST_BIT(~addr[idx], /* nop */, size);
|
|
}
|
|
EXPORT_SYMBOL(_find_first_zero_bit);
|
|
#endif
|
|
|
|
#ifndef find_next_bit
|
|
unsigned long _find_next_bit(const unsigned long *addr, unsigned long nbits, unsigned long start)
|
|
{
|
|
return FIND_NEXT_BIT(addr[idx], /* nop */, nbits, start);
|
|
}
|
|
EXPORT_SYMBOL(_find_next_bit);
|
|
#endif
|
|
|
|
unsigned long __find_nth_bit(const unsigned long *addr, unsigned long size, unsigned long n)
|
|
{
|
|
return FIND_NTH_BIT(addr[idx], size, n);
|
|
}
|
|
EXPORT_SYMBOL(__find_nth_bit);
|
|
|
|
unsigned long __find_nth_and_bit(const unsigned long *addr1, const unsigned long *addr2,
|
|
unsigned long size, unsigned long n)
|
|
{
|
|
return FIND_NTH_BIT(addr1[idx] & addr2[idx], size, n);
|
|
}
|
|
EXPORT_SYMBOL(__find_nth_and_bit);
|
|
|
|
unsigned long __find_nth_andnot_bit(const unsigned long *addr1, const unsigned long *addr2,
|
|
unsigned long size, unsigned long n)
|
|
{
|
|
return FIND_NTH_BIT(addr1[idx] & ~addr2[idx], size, n);
|
|
}
|
|
EXPORT_SYMBOL(__find_nth_andnot_bit);
|
|
|
|
unsigned long __find_nth_and_andnot_bit(const unsigned long *addr1,
|
|
const unsigned long *addr2,
|
|
const unsigned long *addr3,
|
|
unsigned long size, unsigned long n)
|
|
{
|
|
return FIND_NTH_BIT(addr1[idx] & addr2[idx] & ~addr3[idx], size, n);
|
|
}
|
|
EXPORT_SYMBOL(__find_nth_and_andnot_bit);
|
|
|
|
#ifndef find_next_and_bit
|
|
unsigned long _find_next_and_bit(const unsigned long *addr1, const unsigned long *addr2,
|
|
unsigned long nbits, unsigned long start)
|
|
{
|
|
return FIND_NEXT_BIT(addr1[idx] & addr2[idx], /* nop */, nbits, start);
|
|
}
|
|
EXPORT_SYMBOL(_find_next_and_bit);
|
|
#endif
|
|
|
|
#ifndef find_next_andnot_bit
|
|
unsigned long _find_next_andnot_bit(const unsigned long *addr1, const unsigned long *addr2,
|
|
unsigned long nbits, unsigned long start)
|
|
{
|
|
return FIND_NEXT_BIT(addr1[idx] & ~addr2[idx], /* nop */, nbits, start);
|
|
}
|
|
EXPORT_SYMBOL(_find_next_andnot_bit);
|
|
#endif
|
|
|
|
#ifndef find_next_or_bit
|
|
unsigned long _find_next_or_bit(const unsigned long *addr1, const unsigned long *addr2,
|
|
unsigned long nbits, unsigned long start)
|
|
{
|
|
return FIND_NEXT_BIT(addr1[idx] | addr2[idx], /* nop */, nbits, start);
|
|
}
|
|
EXPORT_SYMBOL(_find_next_or_bit);
|
|
#endif
|
|
|
|
#ifndef find_next_zero_bit
|
|
unsigned long _find_next_zero_bit(const unsigned long *addr, unsigned long nbits,
|
|
unsigned long start)
|
|
{
|
|
return FIND_NEXT_BIT(~addr[idx], /* nop */, nbits, start);
|
|
}
|
|
EXPORT_SYMBOL(_find_next_zero_bit);
|
|
#endif
|
|
|
|
#ifndef find_last_bit
|
|
unsigned long _find_last_bit(const unsigned long *addr, unsigned long size)
|
|
{
|
|
if (size) {
|
|
unsigned long val = BITMAP_LAST_WORD_MASK(size);
|
|
unsigned long idx = (size-1) / BITS_PER_LONG;
|
|
|
|
do {
|
|
val &= addr[idx];
|
|
if (val)
|
|
return idx * BITS_PER_LONG + __fls(val);
|
|
|
|
val = ~0ul;
|
|
} while (idx--);
|
|
}
|
|
return size;
|
|
}
|
|
EXPORT_SYMBOL(_find_last_bit);
|
|
#endif
|
|
|
|
unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr,
|
|
unsigned long size, unsigned long offset)
|
|
{
|
|
offset = find_next_bit(addr, size, offset);
|
|
if (offset == size)
|
|
return size;
|
|
|
|
offset = round_down(offset, 8);
|
|
*clump = bitmap_get_value8(addr, offset);
|
|
|
|
return offset;
|
|
}
|
|
EXPORT_SYMBOL(find_next_clump8);
|
|
|
|
#ifdef __BIG_ENDIAN
|
|
|
|
#ifndef find_first_zero_bit_le
|
|
/*
|
|
* Find the first cleared bit in an LE memory region.
|
|
*/
|
|
unsigned long _find_first_zero_bit_le(const unsigned long *addr, unsigned long size)
|
|
{
|
|
return FIND_FIRST_BIT(~addr[idx], swab, size);
|
|
}
|
|
EXPORT_SYMBOL(_find_first_zero_bit_le);
|
|
|
|
#endif
|
|
|
|
#ifndef find_next_zero_bit_le
|
|
unsigned long _find_next_zero_bit_le(const unsigned long *addr,
|
|
unsigned long size, unsigned long offset)
|
|
{
|
|
return FIND_NEXT_BIT(~addr[idx], swab, size, offset);
|
|
}
|
|
EXPORT_SYMBOL(_find_next_zero_bit_le);
|
|
#endif
|
|
|
|
#ifndef find_next_bit_le
|
|
unsigned long _find_next_bit_le(const unsigned long *addr,
|
|
unsigned long size, unsigned long offset)
|
|
{
|
|
return FIND_NEXT_BIT(addr[idx], swab, size, offset);
|
|
}
|
|
EXPORT_SYMBOL(_find_next_bit_le);
|
|
|
|
#endif
|
|
|
|
#endif /* __BIG_ENDIAN */
|