mirror of
https://github.com/checkpoint-restore/criu
synced 2025-08-27 20:37:57 +00:00
919df37c25
Borrowed from Linux Kernel v5: New Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
133 lines
3.0 KiB
C
133 lines
3.0 KiB
C
#ifndef __CR_BITOPS_H__
|
|
#define __CR_BITOPS_H__
|
|
|
|
#include "common/arch/x86/asm/cmpxchg.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)]
|
|
|
|
#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)
|
|
{
|
|
asm volatile("btsl %1,%0" : ADDR : "Ir" (nr) : "memory");
|
|
}
|
|
|
|
static inline void change_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
asm volatile("btcl %1,%0" : ADDR : "Ir" (nr));
|
|
}
|
|
|
|
static inline int test_bit(int nr, volatile const unsigned long *addr)
|
|
{
|
|
int oldbit;
|
|
|
|
asm volatile("bt %2,%1\n\t"
|
|
"sbb %0,%0"
|
|
: "=r" (oldbit)
|
|
: "m" (*(unsigned long *)addr), "Ir" (nr));
|
|
|
|
return oldbit;
|
|
}
|
|
|
|
static inline void clear_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
asm volatile("btrl %1,%0" : ADDR : "Ir" (nr));
|
|
}
|
|
|
|
/**
|
|
* test_and_set_bit - Set a bit and return its old value
|
|
* @nr: Bit to set
|
|
* @addr: Address to count from
|
|
*
|
|
* This operation is atomic and cannot be reordered.
|
|
* It also implies a memory barrier.
|
|
*/
|
|
static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
int oldbit;
|
|
|
|
asm volatile(LOCK_PREFIX "bts %2,%1\n\t"
|
|
"sbb %0,%0" : "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
|
|
|
|
return oldbit;
|
|
}
|
|
|
|
/**
|
|
* __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)
|
|
{
|
|
asm("bsf %1,%0"
|
|
: "=r" (word)
|
|
: "rm" (word));
|
|
return word;
|
|
}
|
|
|
|
#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, sizeof(bitmask), 0); \
|
|
i < sizeof(bitmask); \
|
|
i = find_next_bit(bitmask, sizeof(bitmask), i + 1))
|
|
|
|
#endif /* __CR_BITOPS_H__ */
|