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/*
* Generic bits operations.
*
* Architectures that don't want their own implementation of those,
* should include this file into the arch/$ARCH/include/asm/bitops.h
*/
#ifndef __CR_GENERIC_BITOPS_H__
#define __CR_GENERIC_BITOPS_H__
#include "common/asm/bitsperlong.h"
#define DIV_ROUND_UP(n, d) (((n) + (d)-1) / (d))
#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_LONG)
#define DECLARE_BITMAP(name, bits) unsigned long name[BITS_TO_LONGS(bits)]
#define BITMAP_SIZE(name) (sizeof(name) * CHAR_BIT)
#if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
/* Technically wrong, but this avoids compilation errors on some gcc
versions. */
#define BITOP_ADDR(x) "=m"(*(volatile long *)(x))
#else
#define BITOP_ADDR(x) "+m"(*(volatile long *)(x))
#endif
#define ADDR BITOP_ADDR(addr)
static inline void set_bit(int nr, volatile unsigned long *addr)
{
addr += nr / BITS_PER_LONG;
*addr |= (1UL << (nr % BITS_PER_LONG));
}
static inline void change_bit(int nr, volatile unsigned long *addr)
{
addr += nr / BITS_PER_LONG;
*addr ^= (1UL << (nr % BITS_PER_LONG));
}
static inline int test_bit(int nr, volatile const unsigned long *addr)
{
addr += nr / BITS_PER_LONG;
return (*addr & (1UL << (nr % BITS_PER_LONG))) ? -1 : 0;
}
static inline void clear_bit(int nr, volatile unsigned long *addr)
{
addr += nr / BITS_PER_LONG;
*addr &= ~(1UL << (nr % BITS_PER_LONG));
}
/**
* __ffs - find first set bit in word
* @word: The word to search
*
* Undefined if no bit exists, so code should check against 0 first.
*/
static inline unsigned long __ffs(unsigned long word)
{
return __builtin_ffsl(word) - 1;
}
#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
/*
* Find the next set bit in a memory region.
*/
static inline 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);
}
#define for_each_bit(i, bitmask) \
for (i = find_next_bit(bitmask, BITMAP_SIZE(bitmask), 0); i < BITMAP_SIZE(bitmask); \
i = find_next_bit(bitmask, BITMAP_SIZE(bitmask), i + 1))
#endif /* __CR_GENERIC_BITOPS_H__ */
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