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/*
* Copyright (C) 1996 Paul Mackerras.
*/
#include <linux/kernel.h>
#include <asm/bitops.h>
/*
* I left these here since the problems with "cc" make it difficult to keep
* them in bitops.h -- Cort
*/
void set_bit(int nr, volatile void *addr)
{
unsigned int t;
unsigned int mask = 1 << (nr & 0x1f);
volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
if ((unsigned long)addr & 3)
printk(KERN_ERR "set_bit(%x, %p)\n", nr, addr);
__asm__ __volatile__("\n\
1: lwarx %0,0,%2
or %0,%0,%1
stwcx. %0,0,%2
bne 1b"
: "=&r" (t) /*, "=m" (*p)*/
: "r" (mask), "r" (p)
: "cc");
}
void clear_bit(int nr, volatile void *addr)
{
unsigned int t;
unsigned int mask = 1 << (nr & 0x1f);
volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
if ((unsigned long)addr & 3)
printk(KERN_ERR "clear_bit(%x, %p)\n", nr, addr);
__asm__ __volatile__("\n\
1: lwarx %0,0,%2
andc %0,%0,%1
stwcx. %0,0,%2
bne 1b"
: "=&r" (t) /*, "=m" (*p)*/
: "r" (mask), "r" (p)
: "cc");
}
void change_bit(int nr, volatile void *addr)
{
unsigned int t;
unsigned int mask = 1 << (nr & 0x1f);
volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
if ((unsigned long)addr & 3)
printk(KERN_ERR "change_bit(%x, %p)\n", nr, addr);
__asm__ __volatile__("\n\
1: lwarx %0,0,%2
xor %0,%0,%1
stwcx. %0,0,%2
bne 1b"
: "=&r" (t) /*, "=m" (*p)*/
: "r" (mask), "r" (p)
: "cc");
}
int test_and_set_bit(int nr, volatile void *addr)
{
unsigned int old, t;
unsigned int mask = 1 << (nr & 0x1f);
volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
if ((unsigned long)addr & 3)
printk(KERN_ERR "test_and_set_bit(%x, %p)\n", nr, addr);
__asm__ __volatile__("\n\
1: lwarx %0,0,%3
or %1,%0,%2
stwcx. %1,0,%3
bne 1b"
: "=&r" (old), "=&r" (t) /*, "=m" (*p)*/
: "r" (mask), "r" (p)
: "cc");
return (old & mask) != 0;
}
int test_and_clear_bit(int nr, volatile void *addr)
{
unsigned int old, t;
unsigned int mask = 1 << (nr & 0x1f);
volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
if ((unsigned long)addr & 3)
printk(KERN_ERR "test_and_clear_bit(%x, %p)\n", nr, addr);
__asm__ __volatile__("\n\
1: lwarx %0,0,%3
andc %1,%0,%2
stwcx. %1,0,%3
bne 1b"
: "=&r" (old), "=&r" (t) /*, "=m" (*p)*/
: "r" (mask), "r" (p)
: "cc");
return (old & mask) != 0;
}
int test_and_change_bit(int nr, volatile void *addr)
{
unsigned int old, t;
unsigned int mask = 1 << (nr & 0x1f);
volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
if ((unsigned long)addr & 3)
printk(KERN_ERR "test_and_change_bit(%x, %p)\n", nr, addr);
__asm__ __volatile__("\n\
1: lwarx %0,0,%3
xor %1,%0,%2
stwcx. %1,0,%3
bne 1b"
: "=&r" (old), "=&r" (t) /*, "=m" (*p)*/
: "r" (mask), "r" (p)
: "cc");
return (old & mask) != 0;
}
/* I put it in bitops.h -- Cort */
#if 0
int ffz(unsigned int x)
{
int n;
x = ~x & (x+1); /* set LS zero to 1, other bits to 0 */
__asm__ ("cntlzw %0,%1" : "=r" (n) : "r" (x));
return 31 - n;
}
/*
* This implementation of find_{first,next}_zero_bit was stolen from
* Linus' asm-alpha/bitops.h.
*/
int find_first_zero_bit(void * addr, int size)
{
unsigned int * p = ((unsigned int *) addr);
unsigned int result = 0;
unsigned int tmp;
if (size == 0)
return 0;
while (size & ~31UL) {
if (~(tmp = *(p++)))
goto found_middle;
result += 32;
size -= 32;
}
if (!size)
return result;
tmp = *p;
tmp |= ~0UL << size;
found_middle:
return result + ffz(tmp);
}
/*
* Find next zero bit in a bitmap reasonably efficiently..
*/
int find_next_zero_bit(void * addr, int size, int offset)
{
unsigned int * p = ((unsigned int *) addr) + (offset >> 5);
unsigned int result = offset & ~31UL;
unsigned int tmp;
if (offset >= size)
return size;
size -= result;
offset &= 31UL;
if (offset) {
tmp = *(p++);
tmp |= ~0UL >> (32-offset);
if (size < 32)
goto found_first;
if (~tmp)
goto found_middle;
size -= 32;
result += 32;
}
while (size & ~31UL) {
if (~(tmp = *(p++)))
goto found_middle;
result += 32;
size -= 32;
}
if (!size)
return result;
tmp = *p;
found_first:
tmp |= ~0UL << size;
found_middle:
return result + ffz(tmp);
}
#endif
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