mirror of
https://github.com/qemu/qemu.git
synced 2024-11-23 19:03:38 +08:00
bitmap: add a generic bitmap and bitops library
Add most used bitmap and bitops functions into bitmap.c and bitops.c. Theses functions are mostly copied from Linux kernel source. Some of these functions are already redefined in the VNC server. Some of them could be used for some block stuff. The yet yo be submitted NUMA work also need bitmaps. bitops_ffsl() and bitops_flsl() are here because bitops/bitmap works on unsigned long, not int, and we can't use current code because: * ffs only works on int * qemu_fls only works on int * ffsl is a GNU extension Signed-off-by: Corentin Chary <corentincj@iksaif.net> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Corentin Chary
Anthony Liguori
parent
207f328afc
commit
e0e53b2f1b
@ -100,6 +100,7 @@ common-obj-y += msmouse.o ps2.o
|
||||
common-obj-y += qdev.o qdev-properties.o
|
||||
common-obj-y += block-migration.o
|
||||
common-obj-y += pflib.o
|
||||
common-obj-y += bitmap.o bitops.o
|
||||
|
||||
common-obj-$(CONFIG_BRLAPI) += baum.o
|
||||
common-obj-$(CONFIG_POSIX) += migration-exec.o migration-unix.o migration-fd.o
|
||||
|
||||
256
bitmap.c
Normal file
256
bitmap.c
Normal file
@ -0,0 +1,256 @@
|
||||
/*
|
||||
* Bitmap Module
|
||||
*
|
||||
* Stolen from linux/src/lib/bitmap.c
|
||||
*
|
||||
* Copyright (C) 2010 Corentin Chary
|
||||
*
|
||||
* This source code is licensed under the GNU General Public License,
|
||||
* Version 2.
|
||||
*/
|
||||
|
||||
#include "bitops.h"
|
||||
#include "bitmap.h"
|
||||
|
||||
/*
|
||||
* bitmaps provide an array of bits, implemented using an an
|
||||
* array of unsigned longs. The number of valid bits in a
|
||||
* given bitmap does _not_ need to be an exact multiple of
|
||||
* BITS_PER_LONG.
|
||||
*
|
||||
* The possible unused bits in the last, partially used word
|
||||
* of a bitmap are 'don't care'. The implementation makes
|
||||
* no particular effort to keep them zero. It ensures that
|
||||
* their value will not affect the results of any operation.
|
||||
* The bitmap operations that return Boolean (bitmap_empty,
|
||||
* for example) or scalar (bitmap_weight, for example) results
|
||||
* carefully filter out these unused bits from impacting their
|
||||
* results.
|
||||
*
|
||||
* These operations actually hold to a slightly stronger rule:
|
||||
* if you don't input any bitmaps to these ops that have some
|
||||
* unused bits set, then they won't output any set unused bits
|
||||
* in output bitmaps.
|
||||
*
|
||||
* The byte ordering of bitmaps is more natural on little
|
||||
* endian architectures.
|
||||
*/
|
||||
|
||||
int slow_bitmap_empty(const unsigned long *bitmap, int bits)
|
||||
{
|
||||
int k, lim = bits/BITS_PER_LONG;
|
||||
|
||||
for (k = 0; k < lim; ++k) {
|
||||
if (bitmap[k]) {
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
if (bits % BITS_PER_LONG) {
|
||||
if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) {
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
int slow_bitmap_full(const unsigned long *bitmap, int bits)
|
||||
{
|
||||
int k, lim = bits/BITS_PER_LONG;
|
||||
|
||||
for (k = 0; k < lim; ++k) {
|
||||
if (~bitmap[k]) {
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
if (bits % BITS_PER_LONG) {
|
||||
if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) {
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
int slow_bitmap_equal(const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits)
|
||||
{
|
||||
int k, lim = bits/BITS_PER_LONG;
|
||||
|
||||
for (k = 0; k < lim; ++k) {
|
||||
if (bitmap1[k] != bitmap2[k]) {
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
if (bits % BITS_PER_LONG) {
|
||||
if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) {
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
void slow_bitmap_complement(unsigned long *dst, const unsigned long *src,
|
||||
int bits)
|
||||
{
|
||||
int k, lim = bits/BITS_PER_LONG;
|
||||
|
||||
for (k = 0; k < lim; ++k) {
|
||||
dst[k] = ~src[k];
|
||||
}
|
||||
|
||||
if (bits % BITS_PER_LONG) {
|
||||
dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits);
|
||||
}
|
||||
}
|
||||
|
||||
int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits)
|
||||
{
|
||||
int k;
|
||||
int nr = BITS_TO_LONGS(bits);
|
||||
unsigned long result = 0;
|
||||
|
||||
for (k = 0; k < nr; k++) {
|
||||
result |= (dst[k] = bitmap1[k] & bitmap2[k]);
|
||||
}
|
||||
return result != 0;
|
||||
}
|
||||
|
||||
void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits)
|
||||
{
|
||||
int k;
|
||||
int nr = BITS_TO_LONGS(bits);
|
||||
|
||||
for (k = 0; k < nr; k++) {
|
||||
dst[k] = bitmap1[k] | bitmap2[k];
|
||||
}
|
||||
}
|
||||
|
||||
void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits)
|
||||
{
|
||||
int k;
|
||||
int nr = BITS_TO_LONGS(bits);
|
||||
|
||||
for (k = 0; k < nr; k++) {
|
||||
dst[k] = bitmap1[k] ^ bitmap2[k];
|
||||
}
|
||||
}
|
||||
|
||||
int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits)
|
||||
{
|
||||
int k;
|
||||
int nr = BITS_TO_LONGS(bits);
|
||||
unsigned long result = 0;
|
||||
|
||||
for (k = 0; k < nr; k++) {
|
||||
result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
|
||||
}
|
||||
return result != 0;
|
||||
}
|
||||
|
||||
#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
|
||||
|
||||
void bitmap_set(unsigned long *map, int start, int nr)
|
||||
{
|
||||
unsigned long *p = map + BIT_WORD(start);
|
||||
const int size = start + nr;
|
||||
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
|
||||
unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
|
||||
|
||||
while (nr - bits_to_set >= 0) {
|
||||
*p |= mask_to_set;
|
||||
nr -= bits_to_set;
|
||||
bits_to_set = BITS_PER_LONG;
|
||||
mask_to_set = ~0UL;
|
||||
p++;
|
||||
}
|
||||
if (nr) {
|
||||
mask_to_set &= BITMAP_LAST_WORD_MASK(size);
|
||||
*p |= mask_to_set;
|
||||
}
|
||||
}
|
||||
|
||||
void bitmap_clear(unsigned long *map, int start, int nr)
|
||||
{
|
||||
unsigned long *p = map + BIT_WORD(start);
|
||||
const int size = start + nr;
|
||||
int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
|
||||
unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
|
||||
|
||||
while (nr - bits_to_clear >= 0) {
|
||||
*p &= ~mask_to_clear;
|
||||
nr -= bits_to_clear;
|
||||
bits_to_clear = BITS_PER_LONG;
|
||||
mask_to_clear = ~0UL;
|
||||
p++;
|
||||
}
|
||||
if (nr) {
|
||||
mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
|
||||
*p &= ~mask_to_clear;
|
||||
}
|
||||
}
|
||||
|
||||
#define ALIGN_MASK(x,mask) (((x)+(mask))&~(mask))
|
||||
|
||||
/**
|
||||
* bitmap_find_next_zero_area - find a contiguous aligned zero area
|
||||
* @map: The address to base the search on
|
||||
* @size: The bitmap size in bits
|
||||
* @start: The bitnumber to start searching at
|
||||
* @nr: The number of zeroed bits we're looking for
|
||||
* @align_mask: Alignment mask for zero area
|
||||
*
|
||||
* The @align_mask should be one less than a power of 2; the effect is that
|
||||
* the bit offset of all zero areas this function finds is multiples of that
|
||||
* power of 2. A @align_mask of 0 means no alignment is required.
|
||||
*/
|
||||
unsigned long bitmap_find_next_zero_area(unsigned long *map,
|
||||
unsigned long size,
|
||||
unsigned long start,
|
||||
unsigned int nr,
|
||||
unsigned long align_mask)
|
||||
{
|
||||
unsigned long index, end, i;
|
||||
again:
|
||||
index = find_next_zero_bit(map, size, start);
|
||||
|
||||
/* Align allocation */
|
||||
index = ALIGN_MASK(index, align_mask);
|
||||
|
||||
end = index + nr;
|
||||
if (end > size) {
|
||||
return end;
|
||||
}
|
||||
i = find_next_bit(map, end, index);
|
||||
if (i < end) {
|
||||
start = i + 1;
|
||||
goto again;
|
||||
}
|
||||
return index;
|
||||
}
|
||||
|
||||
int slow_bitmap_intersects(const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits)
|
||||
{
|
||||
int k, lim = bits/BITS_PER_LONG;
|
||||
|
||||
for (k = 0; k < lim; ++k) {
|
||||
if (bitmap1[k] & bitmap2[k]) {
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
|
||||
if (bits % BITS_PER_LONG) {
|
||||
if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) {
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
222
bitmap.h
Normal file
222
bitmap.h
Normal file
@ -0,0 +1,222 @@
|
||||
/*
|
||||
* Bitmap Module
|
||||
*
|
||||
* Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
|
||||
*
|
||||
* Mostly inspired by (stolen from) linux/bitmap.h and linux/bitops.h
|
||||
*
|
||||
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
|
||||
* See the COPYING.LIB file in the top-level directory.
|
||||
*/
|
||||
|
||||
#ifndef BITMAP_H
|
||||
#define BITMAP_H
|
||||
|
||||
#include "qemu-common.h"
|
||||
#include "bitops.h"
|
||||
|
||||
/*
|
||||
* The available bitmap operations and their rough meaning in the
|
||||
* case that the bitmap is a single unsigned long are thus:
|
||||
*
|
||||
* Note that nbits should be always a compile time evaluable constant.
|
||||
* Otherwise many inlines will generate horrible code.
|
||||
*
|
||||
* 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_empty(src, nbits) Are all bits zero in *src?
|
||||
* bitmap_full(src, nbits) Are all bits set in *src?
|
||||
* bitmap_set(dst, pos, nbits) Set specified bit area
|
||||
* bitmap_clear(dst, pos, nbits) Clear specified bit area
|
||||
* bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
|
||||
*/
|
||||
|
||||
/*
|
||||
* Also the following operations 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
|
||||
*/
|
||||
|
||||
#define BITMAP_LAST_WORD_MASK(nbits) \
|
||||
( \
|
||||
((nbits) % BITS_PER_LONG) ? \
|
||||
(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \
|
||||
)
|
||||
|
||||
#define DECLARE_BITMAP(name,bits) \
|
||||
unsigned long name[BITS_TO_LONGS(bits)]
|
||||
|
||||
#define small_nbits(nbits) \
|
||||
((nbits) <= BITS_PER_LONG)
|
||||
|
||||
int slow_bitmap_empty(const unsigned long *bitmap, int bits);
|
||||
int slow_bitmap_full(const unsigned long *bitmap, int bits);
|
||||
int slow_bitmap_equal(const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits);
|
||||
void slow_bitmap_complement(unsigned long *dst, const unsigned long *src,
|
||||
int bits);
|
||||
void slow_bitmap_shift_right(unsigned long *dst,
|
||||
const unsigned long *src, int shift, int bits);
|
||||
void slow_bitmap_shift_left(unsigned long *dst,
|
||||
const unsigned long *src, int shift, int bits);
|
||||
int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits);
|
||||
void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits);
|
||||
void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits);
|
||||
int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits);
|
||||
int slow_bitmap_intersects(const unsigned long *bitmap1,
|
||||
const unsigned long *bitmap2, int bits);
|
||||
|
||||
static inline unsigned long *bitmap_new(int nbits)
|
||||
{
|
||||
int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
|
||||
return qemu_mallocz(len);
|
||||
}
|
||||
|
||||
static inline void bitmap_zero(unsigned long *dst, int nbits)
|
||||
{
|
||||
if (small_nbits(nbits)) {
|
||||
*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 (!small_nbits(nbits)) {
|
||||
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 (small_nbits(nbits)) {
|
||||
*dst = *src;
|
||||
} else {
|
||||
int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
|
||||
memcpy(dst, src, len);
|
||||
}
|
||||
}
|
||||
|
||||
static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
|
||||
const unsigned long *src2, int nbits)
|
||||
{
|
||||
if (small_nbits(nbits)) {
|
||||
return (*dst = *src1 & *src2) != 0;
|
||||
}
|
||||
return slow_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 (small_nbits(nbits)) {
|
||||
*dst = *src1 | *src2;
|
||||
} else {
|
||||
slow_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 (small_nbits(nbits)) {
|
||||
*dst = *src1 ^ *src2;
|
||||
} else {
|
||||
slow_bitmap_xor(dst, src1, src2, nbits);
|
||||
}
|
||||
}
|
||||
|
||||
static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
|
||||
const unsigned long *src2, int nbits)
|
||||
{
|
||||
if (small_nbits(nbits)) {
|
||||
return (*dst = *src1 & ~(*src2)) != 0;
|
||||
}
|
||||
return slow_bitmap_andnot(dst, src1, src2, nbits);
|
||||
}
|
||||
|
||||
static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
|
||||
int nbits)
|
||||
{
|
||||
if (small_nbits(nbits)) {
|
||||
*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
|
||||
} else {
|
||||
slow_bitmap_complement(dst, src, nbits);
|
||||
}
|
||||
}
|
||||
|
||||
static inline int bitmap_equal(const unsigned long *src1,
|
||||
const unsigned long *src2, int nbits)
|
||||
{
|
||||
if (small_nbits(nbits)) {
|
||||
return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
|
||||
} else {
|
||||
return slow_bitmap_equal(src1, src2, nbits);
|
||||
}
|
||||
}
|
||||
|
||||
static inline int bitmap_empty(const unsigned long *src, int nbits)
|
||||
{
|
||||
if (small_nbits(nbits)) {
|
||||
return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
|
||||
} else {
|
||||
return slow_bitmap_empty(src, nbits);
|
||||
}
|
||||
}
|
||||
|
||||
static inline int bitmap_full(const unsigned long *src, int nbits)
|
||||
{
|
||||
if (small_nbits(nbits)) {
|
||||
return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
|
||||
} else {
|
||||
return slow_bitmap_full(src, nbits);
|
||||
}
|
||||
}
|
||||
|
||||
static inline int bitmap_intersects(const unsigned long *src1,
|
||||
const unsigned long *src2, int nbits)
|
||||
{
|
||||
if (small_nbits(nbits)) {
|
||||
return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
|
||||
} else {
|
||||
return slow_bitmap_intersects(src1, src2, nbits);
|
||||
}
|
||||
}
|
||||
|
||||
void bitmap_set(unsigned long *map, int i, int len);
|
||||
void bitmap_clear(unsigned long *map, int start, int nr);
|
||||
unsigned long bitmap_find_next_zero_area(unsigned long *map,
|
||||
unsigned long size,
|
||||
unsigned long start,
|
||||
unsigned int nr,
|
||||
unsigned long align_mask);
|
||||
|
||||
#endif /* BITMAP_H */
|
||||
142
bitops.c
Normal file
142
bitops.c
Normal file
@ -0,0 +1,142 @@
|
||||
/*
|
||||
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
|
||||
* Written by David Howells (dhowells@redhat.com)
|
||||
* Copyright (C) 2008 IBM Corporation
|
||||
* Written by Rusty Russell <rusty@rustcorp.com.au>
|
||||
* (Inspired by David Howell's find_next_bit implementation)
|
||||
*
|
||||
* 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; either version
|
||||
* 2 of the License, or (at your option) any later version.
|
||||
*/
|
||||
|
||||
#include "bitops.h"
|
||||
|
||||
#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
|
||||
|
||||
/*
|
||||
* Find the next set bit in a memory region.
|
||||
*/
|
||||
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
|
||||
unsigned long offset)
|
||||
{
|
||||
const unsigned long *p = addr + BITOP_WORD(offset);
|
||||
unsigned long result = offset & ~(BITS_PER_LONG-1);
|
||||
unsigned long tmp;
|
||||
|
||||
if (offset >= size) {
|
||||
return size;
|
||||
}
|
||||
size -= result;
|
||||
offset %= BITS_PER_LONG;
|
||||
if (offset) {
|
||||
tmp = *(p++);
|
||||
tmp &= (~0UL << offset);
|
||||
if (size < BITS_PER_LONG) {
|
||||
goto found_first;
|
||||
}
|
||||
if (tmp) {
|
||||
goto found_middle;
|
||||
}
|
||||
size -= BITS_PER_LONG;
|
||||
result += BITS_PER_LONG;
|
||||
}
|
||||
while (size & ~(BITS_PER_LONG-1)) {
|
||||
if ((tmp = *(p++))) {
|
||||
goto found_middle;
|
||||
}
|
||||
result += BITS_PER_LONG;
|
||||
size -= BITS_PER_LONG;
|
||||
}
|
||||
if (!size) {
|
||||
return result;
|
||||
}
|
||||
tmp = *p;
|
||||
|
||||
found_first:
|
||||
tmp &= (~0UL >> (BITS_PER_LONG - size));
|
||||
if (tmp == 0UL) { /* Are any bits set? */
|
||||
return result + size; /* Nope. */
|
||||
}
|
||||
found_middle:
|
||||
return result + bitops_ffsl(tmp);
|
||||
}
|
||||
|
||||
/*
|
||||
* This implementation of find_{first,next}_zero_bit was stolen from
|
||||
* Linus' asm-alpha/bitops.h.
|
||||
*/
|
||||
unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
|
||||
unsigned long offset)
|
||||
{
|
||||
const unsigned long *p = addr + BITOP_WORD(offset);
|
||||
unsigned long result = offset & ~(BITS_PER_LONG-1);
|
||||
unsigned long tmp;
|
||||
|
||||
if (offset >= size) {
|
||||
return size;
|
||||
}
|
||||
size -= result;
|
||||
offset %= BITS_PER_LONG;
|
||||
if (offset) {
|
||||
tmp = *(p++);
|
||||
tmp |= ~0UL >> (BITS_PER_LONG - offset);
|
||||
if (size < BITS_PER_LONG) {
|
||||
goto found_first;
|
||||
}
|
||||
if (~tmp) {
|
||||
goto found_middle;
|
||||
}
|
||||
size -= BITS_PER_LONG;
|
||||
result += BITS_PER_LONG;
|
||||
}
|
||||
while (size & ~(BITS_PER_LONG-1)) {
|
||||
if (~(tmp = *(p++))) {
|
||||
goto found_middle;
|
||||
}
|
||||
result += BITS_PER_LONG;
|
||||
size -= BITS_PER_LONG;
|
||||
}
|
||||
if (!size) {
|
||||
return result;
|
||||
}
|
||||
tmp = *p;
|
||||
|
||||
found_first:
|
||||
tmp |= ~0UL << size;
|
||||
if (tmp == ~0UL) { /* Are any bits zero? */
|
||||
return result + size; /* Nope. */
|
||||
}
|
||||
found_middle:
|
||||
return result + ffz(tmp);
|
||||
}
|
||||
|
||||
unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
|
||||
{
|
||||
unsigned long words;
|
||||
unsigned long tmp;
|
||||
|
||||
/* Start at final word. */
|
||||
words = size / BITS_PER_LONG;
|
||||
|
||||
/* Partial final word? */
|
||||
if (size & (BITS_PER_LONG-1)) {
|
||||
tmp = (addr[words] & (~0UL >> (BITS_PER_LONG
|
||||
- (size & (BITS_PER_LONG-1)))));
|
||||
if (tmp) {
|
||||
goto found;
|
||||
}
|
||||
}
|
||||
|
||||
while (words) {
|
||||
tmp = addr[--words];
|
||||
if (tmp) {
|
||||
found:
|
||||
return words * BITS_PER_LONG + bitops_flsl(tmp);
|
||||
}
|
||||
}
|
||||
|
||||
/* Not found */
|
||||
return size;
|
||||
}
|
||||
272
bitops.h
Normal file
272
bitops.h
Normal file
@ -0,0 +1,272 @@
|
||||
/*
|
||||
* Bitops Module
|
||||
*
|
||||
* Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
|
||||
*
|
||||
* Mostly inspired by (stolen from) linux/bitmap.h and linux/bitops.h
|
||||
*
|
||||
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
|
||||
* See the COPYING.LIB file in the top-level directory.
|
||||
*/
|
||||
|
||||
#ifndef BITOPS_H
|
||||
#define BITOPS_H
|
||||
|
||||
#include "qemu-common.h"
|
||||
|
||||
#define BITS_PER_BYTE CHAR_BIT
|
||||
#define BITS_PER_LONG (sizeof (unsigned long) * BITS_PER_BYTE)
|
||||
|
||||
#define BIT(nr) (1UL << (nr))
|
||||
#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
|
||||
#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
|
||||
#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
|
||||
|
||||
/**
|
||||
* bitops_ffs - find first bit in word.
|
||||
* @word: The word to search
|
||||
*
|
||||
* Undefined if no bit exists, so code should check against 0 first.
|
||||
*/
|
||||
static unsigned long bitops_ffsl(unsigned long word)
|
||||
{
|
||||
int num = 0;
|
||||
|
||||
#if LONG_MAX > 0x7FFFFFFF
|
||||
if ((word & 0xffffffff) == 0) {
|
||||
num += 32;
|
||||
word >>= 32;
|
||||
}
|
||||
#endif
|
||||
if ((word & 0xffff) == 0) {
|
||||
num += 16;
|
||||
word >>= 16;
|
||||
}
|
||||
if ((word & 0xff) == 0) {
|
||||
num += 8;
|
||||
word >>= 8;
|
||||
}
|
||||
if ((word & 0xf) == 0) {
|
||||
num += 4;
|
||||
word >>= 4;
|
||||
}
|
||||
if ((word & 0x3) == 0) {
|
||||
num += 2;
|
||||
word >>= 2;
|
||||
}
|
||||
if ((word & 0x1) == 0) {
|
||||
num += 1;
|
||||
}
|
||||
return num;
|
||||
}
|
||||
|
||||
/**
|
||||
* bitops_fls - find last (most-significant) set bit in a long word
|
||||
* @word: the word to search
|
||||
*
|
||||
* Undefined if no set bit exists, so code should check against 0 first.
|
||||
*/
|
||||
static __always_inline unsigned long bitops_flsl(unsigned long word)
|
||||
{
|
||||
int num = BITS_PER_LONG - 1;
|
||||
|
||||
#if LONG_MAX > 0x7FFFFFFF
|
||||
if (!(word & (~0ul << 32))) {
|
||||
num -= 32;
|
||||
word <<= 32;
|
||||
}
|
||||
#endif
|
||||
if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
|
||||
num -= 16;
|
||||
word <<= 16;
|
||||
}
|
||||
if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
|
||||
num -= 8;
|
||||
word <<= 8;
|
||||
}
|
||||
if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
|
||||
num -= 4;
|
||||
word <<= 4;
|
||||
}
|
||||
if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
|
||||
num -= 2;
|
||||
|
||||
word <<= 2;
|
||||
}
|
||||
if (!(word & (~0ul << (BITS_PER_LONG-1))))
|
||||
num -= 1;
|
||||
return num;
|
||||
}
|
||||
|
||||
/**
|
||||
* ffz - find first zero in word.
|
||||
* @word: The word to search
|
||||
*
|
||||
* Undefined if no zero exists, so code should check against ~0UL first.
|
||||
*/
|
||||
static inline unsigned long ffz(unsigned long word)
|
||||
{
|
||||
return bitops_ffsl(~word);
|
||||
}
|
||||
|
||||
/**
|
||||
* set_bit - Set a bit in memory
|
||||
* @nr: the bit to set
|
||||
* @addr: the address to start counting from
|
||||
*/
|
||||
static inline void set_bit(int nr, volatile unsigned long *addr)
|
||||
{
|
||||
unsigned long mask = BIT_MASK(nr);
|
||||
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
|
||||
|
||||
*p |= mask;
|
||||
}
|
||||
|
||||
/**
|
||||
* clear_bit - Clears a bit in memory
|
||||
* @nr: Bit to clear
|
||||
* @addr: Address to start counting from
|
||||
*/
|
||||
static inline void clear_bit(int nr, volatile unsigned long *addr)
|
||||
{
|
||||
unsigned long mask = BIT_MASK(nr);
|
||||
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
|
||||
|
||||
*p &= ~mask;
|
||||
}
|
||||
|
||||
/**
|
||||
* change_bit - Toggle a bit in memory
|
||||
* @nr: Bit to change
|
||||
* @addr: Address to start counting from
|
||||
*/
|
||||
static inline void change_bit(int nr, volatile unsigned long *addr)
|
||||
{
|
||||
unsigned long mask = BIT_MASK(nr);
|
||||
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
|
||||
|
||||
*p ^= mask;
|
||||
}
|
||||
|
||||
/**
|
||||
* test_and_set_bit - Set a bit and return its old value
|
||||
* @nr: Bit to set
|
||||
* @addr: Address to count from
|
||||
*/
|
||||
static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
|
||||
{
|
||||
unsigned long mask = BIT_MASK(nr);
|
||||
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
|
||||
unsigned long old = *p;
|
||||
|
||||
*p = old | mask;
|
||||
return (old & mask) != 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* test_and_clear_bit - Clear a bit and return its old value
|
||||
* @nr: Bit to clear
|
||||
* @addr: Address to count from
|
||||
*/
|
||||
static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
|
||||
{
|
||||
unsigned long mask = BIT_MASK(nr);
|
||||
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
|
||||
unsigned long old = *p;
|
||||
|
||||
*p = old & ~mask;
|
||||
return (old & mask) != 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* test_and_change_bit - Change a bit and return its old value
|
||||
* @nr: Bit to change
|
||||
* @addr: Address to count from
|
||||
*/
|
||||
static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
|
||||
{
|
||||
unsigned long mask = BIT_MASK(nr);
|
||||
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
|
||||
unsigned long old;
|
||||
|
||||
*p = old ^ mask;
|
||||
return (old & mask) != 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* test_bit - Determine whether a bit is set
|
||||
* @nr: bit number to test
|
||||
* @addr: Address to start counting from
|
||||
*/
|
||||
static inline int test_bit(int nr, const volatile unsigned long *addr)
|
||||
{
|
||||
return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
|
||||
}
|
||||
|
||||
/**
|
||||
* find_last_bit - find the last set bit in a memory region
|
||||
* @addr: The address to start the search at
|
||||
* @size: The maximum size to search
|
||||
*
|
||||
* Returns the bit number of the first set bit, or size.
|
||||
*/
|
||||
unsigned long find_last_bit(const unsigned long *addr,
|
||||
unsigned long size);
|
||||
|
||||
/**
|
||||
* find_next_bit - find the next set bit in a memory region
|
||||
* @addr: The address to base the search on
|
||||
* @offset: The bitnumber to start searching at
|
||||
* @size: The bitmap size in bits
|
||||
*/
|
||||
unsigned long find_next_bit(const unsigned long *addr,
|
||||
unsigned long size, unsigned long offset);
|
||||
|
||||
/**
|
||||
* find_next_zero_bit - find the next cleared bit in a memory region
|
||||
* @addr: The address to base the search on
|
||||
* @offset: The bitnumber to start searching at
|
||||
* @size: The bitmap size in bits
|
||||
*/
|
||||
|
||||
unsigned long find_next_zero_bit(const unsigned long *addr,
|
||||
unsigned long size,
|
||||
unsigned long offset);
|
||||
|
||||
/**
|
||||
* find_first_bit - find the first set bit in a memory region
|
||||
* @addr: The address to start the search at
|
||||
* @size: The maximum size to search
|
||||
*
|
||||
* Returns the bit number of the first set bit.
|
||||
*/
|
||||
static inline unsigned long find_first_bit(const unsigned long *addr,
|
||||
unsigned long size)
|
||||
{
|
||||
return find_next_bit(addr, size, 0);
|
||||
}
|
||||
|
||||
/**
|
||||
* find_first_zero_bit - find the first cleared bit in a memory region
|
||||
* @addr: The address to start the search at
|
||||
* @size: The maximum size to search
|
||||
*
|
||||
* Returns the bit number of the first cleared bit.
|
||||
*/
|
||||
static inline unsigned long find_first_zero_bit(const unsigned long *addr,
|
||||
unsigned long size)
|
||||
{
|
||||
return find_next_zero_bit(addr, size, 0);
|
||||
}
|
||||
|
||||
static inline unsigned long hweight_long(unsigned long w)
|
||||
{
|
||||
unsigned long count;
|
||||
|
||||
for (count = 0; w; w >>= 1) {
|
||||
count += w & 1;
|
||||
}
|
||||
return count;
|
||||
}
|
||||
|
||||
#endif
|
||||
Loading…
Reference in New Issue
Block a user