/*
 * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2.  This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#ifndef __ASM_OPENRISC_ATOMIC_H
#define __ASM_OPENRISC_ATOMIC_H

#include <linux/types.h>

/* Atomically perform op with v->counter and i */
#define ATOMIC_OP(op)                                                   \
static inline void arch_atomic_##op(int i, atomic_t *v)                 \
{                                                                       \
        int tmp;                                                        \
                                                                        \
        __asm__ __volatile__(                                           \
                "1:     l.lwa   %0,0(%1)        \n"                     \
                "       l." #op " %0,%0,%2      \n"                     \
                "       l.swa   0(%1),%0        \n"                     \
                "       l.bnf   1b              \n"                     \
                "        l.nop                  \n"                     \
                : "=&r"(tmp)                                            \
                : "r"(&v->counter), "r"(i)                              \
                : "cc", "memory");                                      \
}

/* Atomically perform op with v->counter and i, return the result */
#define ATOMIC_OP_RETURN(op)                                            \
static inline int arch_atomic_##op##_return(int i, atomic_t *v)         \
{                                                                       \
        int tmp;                                                        \
                                                                        \
        __asm__ __volatile__(                                           \
                "1:     l.lwa   %0,0(%1)        \n"                     \
                "       l." #op " %0,%0,%2      \n"                     \
                "       l.swa   0(%1),%0        \n"                     \
                "       l.bnf   1b              \n"                     \
                "        l.nop                  \n"                     \
                : "=&r"(tmp)                                            \
                : "r"(&v->counter), "r"(i)                              \
                : "cc", "memory");                                      \
                                                                        \
        return tmp;                                                     \
}

/* Atomically perform op with v->counter and i, return orig v->counter */
#define ATOMIC_FETCH_OP(op)                                             \
static inline int arch_atomic_fetch_##op(int i, atomic_t *v)            \
{                                                                       \
        int tmp, old;                                                   \
                                                                        \
        __asm__ __volatile__(                                           \
                "1:     l.lwa   %0,0(%2)        \n"                     \
                "       l." #op " %1,%0,%3      \n"                     \
                "       l.swa   0(%2),%1        \n"                     \
                "       l.bnf   1b              \n"                     \
                "        l.nop                  \n"                     \
                : "=&r"(old), "=&r"(tmp)                                \
                : "r"(&v->counter), "r"(i)                              \
                : "cc", "memory");                                      \
                                                                        \
        return old;                                                     \
}

ATOMIC_OP_RETURN(add)
ATOMIC_OP_RETURN(sub)

ATOMIC_FETCH_OP(add)
ATOMIC_FETCH_OP(sub)
ATOMIC_FETCH_OP(and)
ATOMIC_FETCH_OP(or)
ATOMIC_FETCH_OP(xor)

ATOMIC_OP(add)
ATOMIC_OP(sub)
ATOMIC_OP(and)
ATOMIC_OP(or)
ATOMIC_OP(xor)

#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP

#define arch_atomic_add_return  arch_atomic_add_return
#define arch_atomic_sub_return  arch_atomic_sub_return
#define arch_atomic_fetch_add   arch_atomic_fetch_add
#define arch_atomic_fetch_sub   arch_atomic_fetch_sub
#define arch_atomic_fetch_and   arch_atomic_fetch_and
#define arch_atomic_fetch_or    arch_atomic_fetch_or
#define arch_atomic_fetch_xor   arch_atomic_fetch_xor
#define arch_atomic_add         arch_atomic_add
#define arch_atomic_sub         arch_atomic_sub
#define arch_atomic_and         arch_atomic_and
#define arch_atomic_or          arch_atomic_or
#define arch_atomic_xor         arch_atomic_xor

/*
 * Atomically add a to v->counter as long as v is not already u.
 * Returns the original value at v->counter.
 *
 * This is often used through atomic_inc_not_zero()
 */
static inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
{
        int old, tmp;

        __asm__ __volatile__(
                "1:     l.lwa %0, 0(%2)         \n"
                "       l.sfeq %0, %4           \n"
                "       l.bf 2f                 \n"
                "        l.add %1, %0, %3       \n"
                "       l.swa 0(%2), %1         \n"
                "       l.bnf 1b                \n"
                "        l.nop                  \n"
                "2:                             \n"
                : "=&r"(old), "=&r" (tmp)
                : "r"(&v->counter), "r"(a), "r"(u)
                : "cc", "memory");

        return old;
}
#define arch_atomic_fetch_add_unless    arch_atomic_fetch_add_unless

#define arch_atomic_read(v)             READ_ONCE((v)->counter)
#define arch_atomic_set(v,i)            WRITE_ONCE((v)->counter, (i))

#include <asm/cmpxchg.h>

#endif /* __ASM_OPENRISC_ATOMIC_H */