alistair23-linux/include/linux/bitmap.h
Paul Jackson fb5eeeee44 [PATCH] cpusets: bitmap and mask remap operators
In the forthcoming task migration support, a key calculation will be
mapping cpu and node numbers from the old set to the new set while
preserving cpuset-relative offset.

For example, if a task and its pages on nodes 8-11 are being migrated to
nodes 24-27, then pages on node 9 (the 2nd node in the old set) should be
moved to node 25 (the 2nd node in the new set.)

As with other bitmap operations, the proper way to code this is to provide
the underlying calculation in lib/bitmap.c, and then to provide the usual
cpumask and nodemask wrappers.

This patch provides that.  These operations are termed 'remap' operations.
Both remapping a single bit and a set of bits is supported.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:21 -08:00

268 lines
8.7 KiB
C

#ifndef __LINUX_BITMAP_H
#define __LINUX_BITMAP_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/string.h>
/*
* bitmaps provide bit arrays that consume one or more unsigned
* longs. The bitmap interface and available operations are listed
* here, in bitmap.h
*
* Function implementations generic to all architectures are in
* lib/bitmap.c. Functions implementations that are architecture
* specific are in various include/asm-<arch>/bitops.h headers
* and other arch/<arch> specific files.
*
* See lib/bitmap.c for more details.
*/
/*
* The available bitmap operations and their rough meaning in the
* case that the bitmap is a single unsigned long are thus:
*
* bitmap_zero(dst, nbits) *dst = 0UL
* bitmap_fill(dst, nbits) *dst = ~0UL
* bitmap_copy(dst, src, nbits) *dst = *src
* bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
* bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
* bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
* bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
* bitmap_complement(dst, src, nbits) *dst = ~(*src)
* bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
* bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
* bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
* bitmap_empty(src, nbits) Are all bits zero in *src?
* bitmap_full(src, nbits) Are all bits set in *src?
* bitmap_weight(src, nbits) Hamming Weight: number set bits
* bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
* bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
* bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
* bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
* bitmap_scnprintf(buf, len, src, nbits) Print bitmap src to buf
* bitmap_parse(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
* bitmap_scnlistprintf(buf, len, src, nbits) Print bitmap src as list to buf
* bitmap_parselist(buf, dst, nbits) Parse bitmap dst from list
*/
/*
* Also the following operations in asm/bitops.h apply to bitmaps.
*
* set_bit(bit, addr) *addr |= bit
* clear_bit(bit, addr) *addr &= ~bit
* change_bit(bit, addr) *addr ^= bit
* test_bit(bit, addr) Is bit set in *addr?
* test_and_set_bit(bit, addr) Set bit and return old value
* test_and_clear_bit(bit, addr) Clear bit and return old value
* test_and_change_bit(bit, addr) Change bit and return old value
* find_first_zero_bit(addr, nbits) Position first zero bit in *addr
* find_first_bit(addr, nbits) Position first set bit in *addr
* find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
* find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
*/
/*
* The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
* to declare an array named 'name' of just enough unsigned longs to
* contain all bit positions from 0 to 'bits' - 1.
*/
/*
* lib/bitmap.c provides these functions:
*/
extern int __bitmap_empty(const unsigned long *bitmap, int bits);
extern int __bitmap_full(const unsigned long *bitmap, int bits);
extern int __bitmap_equal(const unsigned long *bitmap1,
const unsigned long *bitmap2, int bits);
extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
int bits);
extern void __bitmap_shift_right(unsigned long *dst,
const unsigned long *src, int shift, int bits);
extern void __bitmap_shift_left(unsigned long *dst,
const unsigned long *src, int shift, int bits);
extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
const unsigned long *bitmap2, int bits);
extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
const unsigned long *bitmap2, int bits);
extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
const unsigned long *bitmap2, int bits);
extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
const unsigned long *bitmap2, int bits);
extern int __bitmap_intersects(const unsigned long *bitmap1,
const unsigned long *bitmap2, int bits);
extern int __bitmap_subset(const unsigned long *bitmap1,
const unsigned long *bitmap2, int bits);
extern int __bitmap_weight(const unsigned long *bitmap, int bits);
extern int bitmap_scnprintf(char *buf, unsigned int len,
const unsigned long *src, int nbits);
extern int bitmap_parse(const char __user *ubuf, unsigned int ulen,
unsigned long *dst, int nbits);
extern int bitmap_scnlistprintf(char *buf, unsigned int len,
const unsigned long *src, int nbits);
extern int bitmap_parselist(const char *buf, unsigned long *maskp,
int nmaskbits);
extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
const unsigned long *old, const unsigned long *new, int bits);
extern int bitmap_bitremap(int oldbit,
const unsigned long *old, const unsigned long *new, int bits);
extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
#define BITMAP_LAST_WORD_MASK(nbits) \
( \
((nbits) % BITS_PER_LONG) ? \
(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \
)
static inline void bitmap_zero(unsigned long *dst, int nbits)
{
if (nbits <= BITS_PER_LONG)
*dst = 0UL;
else {
int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
memset(dst, 0, len);
}
}
static inline void bitmap_fill(unsigned long *dst, int nbits)
{
size_t nlongs = BITS_TO_LONGS(nbits);
if (nlongs > 1) {
int len = (nlongs - 1) * sizeof(unsigned long);
memset(dst, 0xff, len);
}
dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
}
static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
int nbits)
{
if (nbits <= BITS_PER_LONG)
*dst = *src;
else {
int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
memcpy(dst, src, len);
}
}
static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
const unsigned long *src2, int nbits)
{
if (nbits <= BITS_PER_LONG)
*dst = *src1 & *src2;
else
__bitmap_and(dst, src1, src2, nbits);
}
static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
const unsigned long *src2, int nbits)
{
if (nbits <= BITS_PER_LONG)
*dst = *src1 | *src2;
else
__bitmap_or(dst, src1, src2, nbits);
}
static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
const unsigned long *src2, int nbits)
{
if (nbits <= BITS_PER_LONG)
*dst = *src1 ^ *src2;
else
__bitmap_xor(dst, src1, src2, nbits);
}
static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
const unsigned long *src2, int nbits)
{
if (nbits <= BITS_PER_LONG)
*dst = *src1 & ~(*src2);
else
__bitmap_andnot(dst, src1, src2, nbits);
}
static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
int nbits)
{
if (nbits <= BITS_PER_LONG)
*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
else
__bitmap_complement(dst, src, nbits);
}
static inline int bitmap_equal(const unsigned long *src1,
const unsigned long *src2, int nbits)
{
if (nbits <= BITS_PER_LONG)
return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
else
return __bitmap_equal(src1, src2, nbits);
}
static inline int bitmap_intersects(const unsigned long *src1,
const unsigned long *src2, int nbits)
{
if (nbits <= BITS_PER_LONG)
return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
else
return __bitmap_intersects(src1, src2, nbits);
}
static inline int bitmap_subset(const unsigned long *src1,
const unsigned long *src2, int nbits)
{
if (nbits <= BITS_PER_LONG)
return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
else
return __bitmap_subset(src1, src2, nbits);
}
static inline int bitmap_empty(const unsigned long *src, int nbits)
{
if (nbits <= BITS_PER_LONG)
return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
else
return __bitmap_empty(src, nbits);
}
static inline int bitmap_full(const unsigned long *src, int nbits)
{
if (nbits <= BITS_PER_LONG)
return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
else
return __bitmap_full(src, nbits);
}
static inline int bitmap_weight(const unsigned long *src, int nbits)
{
return __bitmap_weight(src, nbits);
}
static inline void bitmap_shift_right(unsigned long *dst,
const unsigned long *src, int n, int nbits)
{
if (nbits <= BITS_PER_LONG)
*dst = *src >> n;
else
__bitmap_shift_right(dst, src, n, nbits);
}
static inline void bitmap_shift_left(unsigned long *dst,
const unsigned long *src, int n, int nbits)
{
if (nbits <= BITS_PER_LONG)
*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
else
__bitmap_shift_left(dst, src, n, nbits);
}
#endif /* __ASSEMBLY__ */
#endif /* __LINUX_BITMAP_H */