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[lttv.git] / trunk / obsolete / ltt-usertrace / ltt / system-ppc.h

/*
 * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
 */
#ifndef __PPC_SYSTEM_H
#define __PPC_SYSTEM_H

#include <asm/atomic.h>
#include <asm/hw_irq.h>

#ifdef __cplusplus
extern "C" {
#endif

/*
 * Memory barrier.
 * The sync instruction guarantees that all memory accesses initiated
 * by this processor have been performed (with respect to all other
 * mechanisms that access memory).  The eieio instruction is a barrier
 * providing an ordering (separately) for (a) cacheable stores and (b)
 * loads and stores to non-cacheable memory (e.g. I/O devices).
 *
 * mb() prevents loads and stores being reordered across this point.
 * rmb() prevents loads being reordered across this point.
 * wmb() prevents stores being reordered across this point.
 * read_barrier_depends() prevents data-dependent loads being reordered
 *	across this point (nop on PPC).
 *
 * We can use the eieio instruction for wmb, but since it doesn't
 * give any ordering guarantees about loads, we have to use the
 * stronger but slower sync instruction for mb and rmb.
 */
#define mb()  __asm__ __volatile__ ("sync" : : : "memory")
#define rmb()  __asm__ __volatile__ ("sync" : : : "memory")
#define wmb()  __asm__ __volatile__ ("eieio" : : : "memory")
#define read_barrier_depends()  do { } while(0)

#define set_mb(var, value)	do { var = value; mb(); } while (0)
#define set_wmb(var, value)	do { var = value; wmb(); } while (0)

#ifdef CONFIG_SMP
#define smp_mb()	mb()
#define smp_rmb()	rmb()
#define smp_wmb()	wmb()
#define smp_read_barrier_depends()	read_barrier_depends()
#else
#define smp_mb()	barrier()
#define smp_rmb()	barrier()
#define smp_wmb()	barrier()
#define smp_read_barrier_depends()	do { } while(0)
#endif /* CONFIG_SMP */

static inline unsigned long
xchg_u32(volatile void *p, unsigned long val)
{
	unsigned long prev;

	__asm__ __volatile__ ("\n\
1:	lwarx	%0,0,%2 \n"
	PPC405_ERR77(0,%2)
"	stwcx.	%3,0,%2 \n\
	bne-	1b"
	: "=&r" (prev), "=m" (*(volatile unsigned long *)p)
	: "r" (p), "r" (val), "m" (*(volatile unsigned long *)p)
	: "cc", "memory");

	return prev;
}

/*
 * This function doesn't exist, so you'll get a linker error
 * if something tries to do an invalid xchg().
 */
extern void __xchg_called_with_bad_pointer(void);

#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
#define tas(ptr) (xchg((ptr),1))

static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
{
	switch (size) {
	case 4:
		return (unsigned long) xchg_u32(ptr, x);
#if 0	/* xchg_u64 doesn't exist on 32-bit PPC */
	case 8:
		return (unsigned long) xchg_u64(ptr, x);
#endif /* 0 */
	}
	__xchg_called_with_bad_pointer();
	return x;


}

extern inline void * xchg_ptr(void * m, void * val)
{
	return (void *) xchg_u32(m, (unsigned long) val);
}


#define __HAVE_ARCH_CMPXCHG	1

static inline unsigned long
__cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new)
{
	unsigned int prev;

	__asm__ __volatile__ ("\n\
1:	lwarx	%0,0,%2 \n\
	cmpw	0,%0,%3 \n\
	bne	2f \n"
	PPC405_ERR77(0,%2)
"	stwcx.	%4,0,%2 \n\
	bne-	1b\n"
#if 0 //only using one CPU at a time (LTT) // def CONFIG_SMP
"	sync\n"
#endif /* CONFIG_SMP */
"2:"
	: "=&r" (prev), "=m" (*p)
	: "r" (p), "r" (old), "r" (new), "m" (*p)
	: "cc", "memory");

	return prev;
}

/* This function doesn't exist, so you'll get a linker error
   if something tries to do an invalid cmpxchg().  */
extern void __cmpxchg_called_with_bad_pointer(void);

static inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
{
	switch (size) {
	case 4:
		return __cmpxchg_u32(ptr, old, new);
#if 0	/* we don't have __cmpxchg_u64 on 32-bit PPC */
	case 8:
		return __cmpxchg_u64(ptr, old, new);
#endif /* 0 */
	}
	__cmpxchg_called_with_bad_pointer();
	return old;
}

#define cmpxchg(ptr,o,n)						 \
  ({									 \
     __typeof__(*(ptr)) _o_ = (o);					 \
     __typeof__(*(ptr)) _n_ = (n);					 \
     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,		 \
				    (unsigned long)_n_, sizeof(*(ptr))); \
  })

#define arch_align_stack(x) (x)

#ifdef __cplusplus
} /* end of extern "C" */
#endif

#endif /* __PPC_SYSTEM_H */