Viewing file:  cmpxchg.h (1.47 KB) -rw-r--r--
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#ifndef __ASM_CRIS_CMPXCHG__
#define __ASM_CRIS_CMPXCHG__
#include <linux/irqflags.h>
static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
{
/* since Etrax doesn't have any atomic xchg instructions, we need to disable
irq's (if enabled) and do it with move.d's */
unsigned long flags,temp;
local_irq_save(flags); /* save flags, including irq enable bit and shut off irqs */
switch (size) {
case 1:
*((unsigned char *)&temp) = x;
x = *(unsigned char *)ptr;
*(unsigned char *)ptr = *((unsigned char *)&temp);
break;
case 2:
*((unsigned short *)&temp) = x;
x = *(unsigned short *)ptr;
*(unsigned short *)ptr = *((unsigned short *)&temp);
break;
case 4:
temp = x;
x = *(unsigned long *)ptr;
*(unsigned long *)ptr = temp;
break;
}
local_irq_restore(flags); /* restore irq enable bit */
return x;
}
#define xchg(ptr,x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
#define tas(ptr) (xchg((ptr),1))
#include <asm-generic/cmpxchg-local.h>
/*
* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
* them available.
*/
#define cmpxchg_local(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
(unsigned long)(n), sizeof(*(ptr))))
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
#ifndef CONFIG_SMP
#include <asm-generic/cmpxchg.h>
#endif
#endif /* __ASM_CRIS_CMPXCHG__ */
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