/**
* __bitmap_shift_right - logical right shift of the bits in a bitmap
* @dst : destination bitmap
* @src : source bitmap
* @shift : shift by this many bits
* @nbits : bitmap size, in bits
*
* Shifting right (dividing) means moving bits in the MS -> LS bit
* direction. Zeros are fed into the vacated MS positions and the
* LS bits shifted off the bottom are lost.
*/
void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
unsigned shift, unsigned nbits)
{
unsigned k, lim = BITS_TO_LONGS(nbits);
unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
for (k = 0; off + k < lim; ++k) {
unsigned long upper, lower;
/*
* If shift is not word aligned, take lower rem bits of
* word above and make them the top rem bits of result.
*/
if (!rem || off + k + 1 >= lim)
upper = 0;
else {
upper = src[off + k + 1];
if (off + k + 1 == lim - 1)
upper &= mask;
upper <<= (BITS_PER_LONG - rem);
}
lower = src[off + k];
if (off + k == lim - 1)
lower &= mask;
lower >>= rem;
dst[k] = lower | upper;
}
if (off)
memset(&dst[lim - off], 0, off*sizeof(unsigned long));
}
int bitmap_full(const unsigned long *src, unsigned int nbits)
{
if (small_const_nbits(nbits))
return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
return find_next_zero_bit(src, nbits, 0UL) == nbits;
}
int __bitmap_weight(const unsigned long *bitmap, int bits)
{
int k, w = 0, lim = bits/BITS_PER_LONG;
for (k = 0; k < lim; k++)
w += hweight_long(bitmap[k]);
if (bits % BITS_PER_LONG)
w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
return w;
}
void slow_bitmap_complement(unsigned long *dst, const unsigned long *src,
long bits)
{
long 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 __bitmap_equal(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int bits)
{
unsigned 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;
}
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;
}
int slow_bitmap_empty(const unsigned long *bitmap, long bits)
{
long 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_intersects(const unsigned long *bitmap1,
const unsigned long *bitmap2, long bits)
{
long 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;
}
bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr)
{
unsigned long *p = map + BIT_WORD(start);
const long size = start + nr;
int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
unsigned long dirty = 0;
unsigned long old_bits;
/* First word */
if (nr - bits_to_clear > 0) {
old_bits = atomic_fetch_and(p, ~mask_to_clear);
dirty |= old_bits & mask_to_clear;
nr -= bits_to_clear;
bits_to_clear = BITS_PER_LONG;
mask_to_clear = ~0UL;
p++;
}
/* Full words */
if (bits_to_clear == BITS_PER_LONG) {
while (nr >= BITS_PER_LONG) {
if (*p) {
old_bits = atomic_xchg(p, 0);
dirty |= old_bits;
}
nr -= BITS_PER_LONG;
p++;
}
}
/* Last word */
if (nr) {
mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
old_bits = atomic_fetch_and(p, ~mask_to_clear);
dirty |= old_bits & mask_to_clear;
} else {
if (!dirty) {
smp_mb();
}
}
return dirty != 0;
}
void bitmap_clear(unsigned long *map, unsigned int start, int len)
{
unsigned long *p = map + BIT_WORD(start);
const unsigned int size = start + len;
int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
while (len - bits_to_clear >= 0) {
*p &= ~mask_to_clear;
len -= bits_to_clear;
bits_to_clear = BITS_PER_LONG;
mask_to_clear = ~0UL;
p++;
}
if (len) {
mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
*p &= ~mask_to_clear;
}
}
void bitmap_clear(unsigned long *map, long start, long nr)
{
unsigned long *p = map + BIT_WORD(start);
const long 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;
}
}
void bitmap_set_atomic(unsigned long *map, long start, long nr)
{
unsigned long *p = map + BIT_WORD(start);
const long size = start + nr;
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
/* First word */
if (nr - bits_to_set > 0) {
atomic_or(p, mask_to_set);
nr -= bits_to_set;
bits_to_set = BITS_PER_LONG;
mask_to_set = ~0UL;
p++;
}
/* Full words */
if (bits_to_set == BITS_PER_LONG) {
while (nr >= BITS_PER_LONG) {
*p = ~0UL;
nr -= BITS_PER_LONG;
p++;
}
}
/* Last word */
if (nr) {
mask_to_set &= BITMAP_LAST_WORD_MASK(size);
atomic_or(p, mask_to_set);
} else {
/* If we avoided the full barrier in atomic_or(), issue a
* barrier to account for the assignments in the while loop.
*/
smp_mb();
}
}
