/*
* Copyright 2004-2011 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/

#ifndef __ARCH_BLACKFIN_CMPXCHG__
#define __ARCH_BLACKFIN_CMPXCHG__

#ifdef CONFIG_SMP

#include <linux/linkage.h>

asmlinkage unsigned long __raw_xchg_1_asm(volatile void *ptr, unsigned long value);
asmlinkage unsigned long __raw_xchg_2_asm(volatile void *ptr, unsigned long value);
asmlinkage unsigned long __raw_xchg_4_asm(volatile void *ptr, unsigned long value);
asmlinkage unsigned long __raw_cmpxchg_1_asm(volatile void *ptr,
unsigned long new, unsigned long old);
asmlinkage unsigned long __raw_cmpxchg_2_asm(volatile void *ptr,
unsigned long new, unsigned long old);
asmlinkage unsigned long __raw_cmpxchg_4_asm(volatile void *ptr,
unsigned long new, unsigned long old);

static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
int size)
{
unsigned long tmp;

switch (size) {
case 1:
tmp = __raw_xchg_1_asm(ptr, x);
break;
case 2:
tmp = __raw_xchg_2_asm(ptr, x);
break;
case 4:
tmp = __raw_xchg_4_asm(ptr, x);
break;
}

return tmp;
}

/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is
* indicated by comparing RETURN with OLD.
*/
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
unsigned long new, int size)
{
unsigned long tmp;

switch (size) {
case 1:
tmp = __raw_cmpxchg_1_asm(ptr, new, old);
break;
case 2:
tmp = __raw_cmpxchg_2_asm(ptr, new, old);
break;
case 4:
tmp = __raw_cmpxchg_4_asm(ptr, new, old);
break;
}

return tmp;
}
#define cmpxchg(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))

#else /* !CONFIG_SMP */

#include <mach/blackfin.h>
#include <asm/irqflags.h>

struct __xchg_dummy {
unsigned long a[100];
};
#define __xg(x) ((volatile struct __xchg_dummy *)(x))

static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
int size)
{
unsigned long tmp = 0;
unsigned long flags;

flags = hard_local_irq_save();

switch (size) {
case 1:
__asm__ __volatile__
("%0 = b%2 (z);\n\t"
"b%2 = %1;\n\t"
: "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 2:
__asm__ __volatile__
("%0 = w%2 (z);\n\t"
"w%2 = %1;\n\t"
: "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 4:
__asm__ __volatile__
("%0 = %2;\n\t"
"%2 = %1;\n\t"
: "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
}
hard_local_irq_restore(flags);
return tmp;
}

#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))

#define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n))
#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n))

#endif /* !CONFIG_SMP */

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

#endif /* __ARCH_BLACKFIN_CMPXCHG__ */