/*
* This is a common helper function for find_next_bit, find_next_zero_bit, and
* find_next_and_bit. The differences are:
* - The "invert" argument, which is XORed with each fetched word before
* searching it for one bits.
* - The optional "addr2", which is anded with "addr1" if present.
*/
static inline unsigned long _find_next_bit(const unsigned long *addr1,
const unsigned long *addr2, unsigned long nbits,
unsigned long start, unsigned long invert)
{
unsigned long tmp;
if (unlikely(start >= nbits))
return nbits;
tmp = addr1[start / BITS_PER_LONG];
if (addr2)
tmp &= addr2[start / BITS_PER_LONG];
tmp ^= invert;
/* Handle 1st word. */
tmp &= BITMAP_FIRST_WORD_MASK(start);
start = round_down(start, BITS_PER_LONG);
while (!tmp) {
start += BITS_PER_LONG;
if (start >= nbits)
return nbits;
tmp = addr1[start / BITS_PER_LONG];
if (addr2)
tmp &= addr2[start / BITS_PER_LONG];
tmp ^= invert;
}
return min(start + __ffs(tmp), nbits);
}
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;
}
}
/*
* This is a common helper function for find_next_bit and
* find_next_zero_bit. The difference is the "invert" argument, which
* is XORed with each fetched word before searching it for one bits.
*/
static unsigned long _find_next_bit(const unsigned long *addr,
unsigned long nbits, unsigned long start, unsigned long invert)
{
unsigned long tmp;
if (!nbits || start >= nbits)
return nbits;
tmp = addr[start / BITS_PER_LONG] ^ invert;
/* Handle 1st word. */
tmp &= BITMAP_FIRST_WORD_MASK(start);
start = round_down(start, BITS_PER_LONG);
while (!tmp) {
start += BITS_PER_LONG;
if (start >= nbits)
return nbits;
tmp = addr[start / BITS_PER_LONG] ^ invert;
}
return min(start + __ffs(tmp), nbits);
}
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();
}
}
