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#include <linux/types.h>
#include <linux/module.h>
#include <asm/byteorder.h>
#include <asm/bitops.h>
/**
* 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 maximum size to search
*/
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 + __ffs(tmp);
}
EXPORT_SYMBOL(find_next_bit);
/*
* 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);
}
EXPORT_SYMBOL(find_next_zero_bit);
static inline unsigned int ext2_ilog2(unsigned int x)
{
int lz;
asm("cntlzw %0,%1": "=r"(lz):"r"(x));
return 31 - lz;
}
static inline unsigned int ext2_ffz(unsigned int x)
{
u32 rc;
if ((x = ~x) == 0)
return 32;
rc = ext2_ilog2(x & -x);
return rc;
}
unsigned long find_next_zero_le_bit(const unsigned long *addr,
unsigned long size, unsigned long offset)
{
const unsigned int *p = ((const unsigned int *)addr) + (offset >> 5);
unsigned int result = offset & ~31;
unsigned int tmp;
if (offset >= size)
return size;
size -= result;
offset &= 31;
if (offset) {
tmp = cpu_to_le32p(p++);
tmp |= ~0U >> (32 - offset); /* bug or feature ? */
if (size < 32)
goto found_first;
if (tmp != ~0)
goto found_middle;
size -= 32;
result += 32;
}
while (size >= 32) {
if ((tmp = cpu_to_le32p(p++)) != ~0)
goto found_middle;
result += 32;
size -= 32;
}
if (!size)
return result;
tmp = cpu_to_le32p(p);
found_first:
tmp |= ~0 << size;
if (tmp == ~0) /* Are any bits zero? */
return result + size; /* Nope. */
found_middle:
return result + ext2_ffz(tmp);
}
EXPORT_SYMBOL(find_next_zero_le_bit);
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