/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ALPHA_ATOMIC_H
#define _ALPHA_ATOMIC_H

#include <linux/types.h>
#include <asm/barrier.h>
#include <asm/cmpxchg.h>

/*
 * Atomic operations that C can't guarantee us.  Useful for
 * resource counting etc...
 *
 * But use these as seldom as possible since they are much slower
 * than regular operations.
 */

/*
 * To ensure dependency ordering is preserved for the _relaxed and
 * _release atomics, an smp_read_barrier_depends() is unconditionally
 * inserted into the _relaxed variants, which are used to build the
 * barriered versions. To avoid redundant back-to-back fences, we can
 * define the _acquire and _fence versions explicitly.
 */
#define __atomic_op_acquire(op, args...)        op##_relaxed(args)
#define __atomic_op_fence                       __atomic_op_release

#define ATOMIC_INIT(i)          { (i) }
#define ATOMIC64_INIT(i)        { (i) }

#define atomic_read(v)          READ_ONCE((v)->counter)
#define atomic64_read(v)        READ_ONCE((v)->counter)

#define atomic_set(v,i)         WRITE_ONCE((v)->counter, (i))
#define atomic64_set(v,i)       WRITE_ONCE((v)->counter, (i))

/*
 * To get proper branch prediction for the main line, we must branch
 * forward to code at the end of this object's .text section, then
 * branch back to restart the operation.
 */

#define ATOMIC_OP(op, asm_op)                                           \
static __inline__ void atomic_##op(int i, atomic_t * v)                 \
{                                                                       \
        unsigned long temp;                                             \
        __asm__ __volatile__(                                           \
        "1:     ldl_l %0,%1\n"                                          \
        "       " #asm_op " %0,%2,%0\n"                                 \
        "       stl_c %0,%1\n"                                          \
        "       beq %0,2f\n"                                            \
        ".subsection 2\n"                                               \
        "2:     br 1b\n"                                                \
        ".previous"                                                     \
        :"=&r" (temp), "=m" (v->counter)                                \
        :"Ir" (i), "m" (v->counter));                                   \
}                                                                       \

#define ATOMIC_OP_RETURN(op, asm_op)                                    \
static inline int atomic_##op##_return_relaxed(int i, atomic_t *v)      \
{                                                                       \
        long temp, result;                                              \
        __asm__ __volatile__(                                           \
        "1:     ldl_l %0,%1\n"                                          \
        "       " #asm_op " %0,%3,%2\n"                                 \
        "       " #asm_op " %0,%3,%0\n"                                 \
        "       stl_c %0,%1\n"                                          \
        "       beq %0,2f\n"                                            \
        ".subsection 2\n"                                               \
        "2:     br 1b\n"                                                \
        ".previous"                                                     \
        :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
        :"Ir" (i), "m" (v->counter) : "memory");                        \
        smp_read_barrier_depends();                                     \
        return result;                                                  \
}

#define ATOMIC_FETCH_OP(op, asm_op)                                     \
static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v)       \
{                                                                       \
        long temp, result;                                              \
        __asm__ __volatile__(                                           \
        "1:     ldl_l %2,%1\n"                                          \
        "       " #asm_op " %2,%3,%0\n"                                 \
        "       stl_c %0,%1\n"                                          \
        "       beq %0,2f\n"                                            \
        ".subsection 2\n"                                               \
        "2:     br 1b\n"                                                \
        ".previous"                                                     \
        :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
        :"Ir" (i), "m" (v->counter) : "memory");                        \
        smp_read_barrier_depends();                                     \
        return result;                                                  \
}

#define ATOMIC64_OP(op, asm_op)                                         \
static __inline__ void atomic64_##op(long i, atomic64_t * v)            \
{                                                                       \
        unsigned long temp;                                             \
        __asm__ __volatile__(                                           \
        "1:     ldq_l %0,%1\n"                                          \
        "       " #asm_op " %0,%2,%0\n"                                 \
        "       stq_c %0,%1\n"                                          \
        "       beq %0,2f\n"                                            \
        ".subsection 2\n"                                               \
        "2:     br 1b\n"                                                \
        ".previous"                                                     \
        :"=&r" (temp), "=m" (v->counter)                                \
        :"Ir" (i), "m" (v->counter));                                   \
}                                                                       \

#define ATOMIC64_OP_RETURN(op, asm_op)                                  \
static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v)   \
{                                                                       \
        long temp, result;                                              \
        __asm__ __volatile__(                                           \
        "1:     ldq_l %0,%1\n"                                          \
        "       " #asm_op " %0,%3,%2\n"                                 \
        "       " #asm_op " %0,%3,%0\n"                                 \
        "       stq_c %0,%1\n"                                          \
        "       beq %0,2f\n"                                            \
        ".subsection 2\n"                                               \
        "2:     br 1b\n"                                                \
        ".previous"                                                     \
        :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
        :"Ir" (i), "m" (v->counter) : "memory");                        \
        smp_read_barrier_depends();                                     \
        return result;                                                  \
}

#define ATOMIC64_FETCH_OP(op, asm_op)                                   \
static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v)    \
{                                                                       \
        long temp, result;                                              \
        __asm__ __volatile__(                                           \
        "1:     ldq_l %2,%1\n"                                          \
        "       " #asm_op " %2,%3,%0\n"                                 \
        "       stq_c %0,%1\n"                                          \
        "       beq %0,2f\n"                                            \
        ".subsection 2\n"                                               \
        "2:     br 1b\n"                                                \
        ".previous"                                                     \
        :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
        :"Ir" (i), "m" (v->counter) : "memory");                        \
        smp_read_barrier_depends();                                     \
        return result;                                                  \
}

#define ATOMIC_OPS(op)                                                  \
        ATOMIC_OP(op, op##l)                                            \
        ATOMIC_OP_RETURN(op, op##l)                                     \
        ATOMIC_FETCH_OP(op, op##l)                                      \
        ATOMIC64_OP(op, op##q)                                          \
        ATOMIC64_OP_RETURN(op, op##q)                                   \
        ATOMIC64_FETCH_OP(op, op##q)

ATOMIC_OPS(add)
ATOMIC_OPS(sub)

#define atomic_add_return_relaxed       atomic_add_return_relaxed
#define atomic_sub_return_relaxed       atomic_sub_return_relaxed
#define atomic_fetch_add_relaxed        atomic_fetch_add_relaxed
#define atomic_fetch_sub_relaxed        atomic_fetch_sub_relaxed

#define atomic64_add_return_relaxed     atomic64_add_return_relaxed
#define atomic64_sub_return_relaxed     atomic64_sub_return_relaxed
#define atomic64_fetch_add_relaxed      atomic64_fetch_add_relaxed
#define atomic64_fetch_sub_relaxed      atomic64_fetch_sub_relaxed

#define atomic_andnot atomic_andnot
#define atomic64_andnot atomic64_andnot

#undef ATOMIC_OPS
#define ATOMIC_OPS(op, asm)                                             \
        ATOMIC_OP(op, asm)                                              \
        ATOMIC_FETCH_OP(op, asm)                                        \
        ATOMIC64_OP(op, asm)                                            \
        ATOMIC64_FETCH_OP(op, asm)

ATOMIC_OPS(and, and)
ATOMIC_OPS(andnot, bic)
ATOMIC_OPS(or, bis)
ATOMIC_OPS(xor, xor)

#define atomic_fetch_and_relaxed        atomic_fetch_and_relaxed
#define atomic_fetch_andnot_relaxed     atomic_fetch_andnot_relaxed
#define atomic_fetch_or_relaxed         atomic_fetch_or_relaxed
#define atomic_fetch_xor_relaxed        atomic_fetch_xor_relaxed

#define atomic64_fetch_and_relaxed      atomic64_fetch_and_relaxed
#define atomic64_fetch_andnot_relaxed   atomic64_fetch_andnot_relaxed
#define atomic64_fetch_or_relaxed       atomic64_fetch_or_relaxed
#define atomic64_fetch_xor_relaxed      atomic64_fetch_xor_relaxed

#undef ATOMIC_OPS
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP

#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))

#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))

/**
 * __atomic_add_unless - add unless the number is a given value
 * @v: pointer of type atomic_t
 * @a: the amount to add to v...
 * @u: ...unless v is equal to u.
 *
 * Atomically adds @a to @v, so long as it was not @u.
 * Returns the old value of @v.
 */
static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
{
        int c, new, old;
        smp_mb();
        __asm__ __volatile__(
        "1:     ldl_l   %[old],%[mem]\n"
        "       cmpeq   %[old],%[u],%[c]\n"
        "       addl    %[old],%[a],%[new]\n"
        "       bne     %[c],2f\n"
        "       stl_c   %[new],%[mem]\n"
        "       beq     %[new],3f\n"
        "2:\n"
        ".subsection 2\n"
        "3:     br      1b\n"
        ".previous"
        : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
        : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
        : "memory");
        smp_mb();
        return old;
}


/**
 * atomic64_add_unless - add unless the number is a given value
 * @v: pointer of type atomic64_t
 * @a: the amount to add to v...
 * @u: ...unless v is equal to u.
 *
 * Atomically adds @a to @v, so long as it was not @u.
 * Returns true iff @v was not @u.
 */
static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
{
        long c, tmp;
        smp_mb();
        __asm__ __volatile__(
        "1:     ldq_l   %[tmp],%[mem]\n"
        "       cmpeq   %[tmp],%[u],%[c]\n"
        "       addq    %[tmp],%[a],%[tmp]\n"
        "       bne     %[c],2f\n"
        "       stq_c   %[tmp],%[mem]\n"
        "       beq     %[tmp],3f\n"
        "2:\n"
        ".subsection 2\n"
        "3:     br      1b\n"
        ".previous"
        : [tmp] "=&r"(tmp), [c] "=&r"(c)
        : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
        : "memory");
        smp_mb();
        return !c;
}

/*
 * atomic64_dec_if_positive - decrement by 1 if old value positive
 * @v: pointer of type atomic_t
 *
 * The function returns the old value of *v minus 1, even if
 * the atomic variable, v, was not decremented.
 */
static inline long atomic64_dec_if_positive(atomic64_t *v)
{
        long old, tmp;
        smp_mb();
        __asm__ __volatile__(
        "1:     ldq_l   %[old],%[mem]\n"
        "       subq    %[old],1,%[tmp]\n"
        "       ble     %[old],2f\n"
        "       stq_c   %[tmp],%[mem]\n"
        "       beq     %[tmp],3f\n"
        "2:\n"
        ".subsection 2\n"
        "3:     br      1b\n"
        ".previous"
        : [old] "=&r"(old), [tmp] "=&r"(tmp)
        : [mem] "m"(*v)
        : "memory");
        smp_mb();
        return old - 1;
}

#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)

#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)

#define atomic_dec_return(v) atomic_sub_return(1,(v))
#define atomic64_dec_return(v) atomic64_sub_return(1,(v))

#define atomic_inc_return(v) atomic_add_return(1,(v))
#define atomic64_inc_return(v) atomic64_add_return(1,(v))

#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)

#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
#define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)

#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)

#define atomic_inc(v) atomic_add(1,(v))
#define atomic64_inc(v) atomic64_add(1,(v))

#define atomic_dec(v) atomic_sub(1,(v))
#define atomic64_dec(v) atomic64_sub(1,(v))

#endif /* _ALPHA_ATOMIC_H */