1/*
  2 * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
  3 *
  4 * This file is licensed under the terms of the GNU General Public License
  5 * version 2.  This program is licensed "as is" without any warranty of any
  6 * kind, whether express or implied.
  7 */
  8
  9#ifndef __ASM_OPENRISC_ATOMIC_H
 10#define __ASM_OPENRISC_ATOMIC_H
 11
 12#include <linux/types.h>
 13
 14/* Atomically perform op with v->counter and i */
 15#define ATOMIC_OP(op)							\
 16static inline void arch_atomic_##op(int i, atomic_t *v)			\
 17{									\
 18	int tmp;							\
 19									\
 20	__asm__ __volatile__(						\
 21		"1:	l.lwa	%0,0(%1)	\n"			\
 22		"	l." #op " %0,%0,%2	\n"			\
 23		"	l.swa	0(%1),%0	\n"			\
 24		"	l.bnf	1b		\n"			\
 25		"	 l.nop			\n"			\
 26		: "=&r"(tmp)						\
 27		: "r"(&v->counter), "r"(i)				\
 28		: "cc", "memory");					\
 29}
 30
 31/* Atomically perform op with v->counter and i, return the result */
 32#define ATOMIC_OP_RETURN(op)						\
 33static inline int arch_atomic_##op##_return(int i, atomic_t *v)		\
 34{									\
 35	int tmp;							\
 36									\
 37	__asm__ __volatile__(						\
 38		"1:	l.lwa	%0,0(%1)	\n"			\
 39		"	l." #op " %0,%0,%2	\n"			\
 40		"	l.swa	0(%1),%0	\n"			\
 41		"	l.bnf	1b		\n"			\
 42		"	 l.nop			\n"			\
 43		: "=&r"(tmp)						\
 44		: "r"(&v->counter), "r"(i)				\
 45		: "cc", "memory");					\
 46									\
 47	return tmp;							\
 48}
 49
 50/* Atomically perform op with v->counter and i, return orig v->counter */
 51#define ATOMIC_FETCH_OP(op)						\
 52static inline int arch_atomic_fetch_##op(int i, atomic_t *v)		\
 53{									\
 54	int tmp, old;							\
 55									\
 56	__asm__ __volatile__(						\
 57		"1:	l.lwa	%0,0(%2)	\n"			\
 58		"	l." #op " %1,%0,%3	\n"			\
 59		"	l.swa	0(%2),%1	\n"			\
 60		"	l.bnf	1b		\n"			\
 61		"	 l.nop			\n"			\
 62		: "=&r"(old), "=&r"(tmp)				\
 63		: "r"(&v->counter), "r"(i)				\
 64		: "cc", "memory");					\
 65									\
 66	return old;							\
 67}
 68
 69ATOMIC_OP_RETURN(add)
 70ATOMIC_OP_RETURN(sub)
 71
 72ATOMIC_FETCH_OP(add)
 73ATOMIC_FETCH_OP(sub)
 74ATOMIC_FETCH_OP(and)
 75ATOMIC_FETCH_OP(or)
 76ATOMIC_FETCH_OP(xor)
 77
 78ATOMIC_OP(add)
 79ATOMIC_OP(sub)
 80ATOMIC_OP(and)
 81ATOMIC_OP(or)
 82ATOMIC_OP(xor)
 83
 84#undef ATOMIC_FETCH_OP
 85#undef ATOMIC_OP_RETURN
 86#undef ATOMIC_OP
 87
 88#define arch_atomic_add_return	arch_atomic_add_return
 89#define arch_atomic_sub_return	arch_atomic_sub_return
 90#define arch_atomic_fetch_add	arch_atomic_fetch_add
 91#define arch_atomic_fetch_sub	arch_atomic_fetch_sub
 92#define arch_atomic_fetch_and	arch_atomic_fetch_and
 93#define arch_atomic_fetch_or	arch_atomic_fetch_or
 94#define arch_atomic_fetch_xor	arch_atomic_fetch_xor
 95#define arch_atomic_add		arch_atomic_add
 96#define arch_atomic_sub		arch_atomic_sub
 97#define arch_atomic_and		arch_atomic_and
 98#define arch_atomic_or		arch_atomic_or
 99#define arch_atomic_xor		arch_atomic_xor
100
101/*
102 * Atomically add a to v->counter as long as v is not already u.
103 * Returns the original value at v->counter.
104 *
105 * This is often used through atomic_inc_not_zero()
106 */
107static inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
108{
109	int old, tmp;
110
111	__asm__ __volatile__(
112		"1:	l.lwa %0, 0(%2)		\n"
113		"	l.sfeq %0, %4		\n"
114		"	l.bf 2f			\n"
115		"	 l.add %1, %0, %3	\n"
116		"	l.swa 0(%2), %1		\n"
117		"	l.bnf 1b		\n"
118		"	 l.nop			\n"
119		"2:				\n"
120		: "=&r"(old), "=&r" (tmp)
121		: "r"(&v->counter), "r"(a), "r"(u)
122		: "cc", "memory");
123
124	return old;
125}
126#define arch_atomic_fetch_add_unless	arch_atomic_fetch_add_unless
127
128#define arch_atomic_read(v)		READ_ONCE((v)->counter)
129#define arch_atomic_set(v,i)		WRITE_ONCE((v)->counter, (i))
130
131#include <asm/cmpxchg.h>
132
133#endif /* __ASM_OPENRISC_ATOMIC_H */