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

#ifdef __KERNEL__

#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>
#include <asm/barrier.h>

#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)      \
        __asm__ __volatile__(                                   \
                __ASM_SMP_MB                                    \
        "1:     ldl_l   %0,0(%2)\n"                             \
                insn                                            \
        "2:     stl_c   %1,0(%2)\n"                             \
        "       beq     %1,4f\n"                                \
        "       mov     $31,%1\n"                               \
        "3:     .subsection 2\n"                                \
        "4:     br      1b\n"                                   \
        "       .previous\n"                                    \
        EXC(1b,3b,$31,%1)                                       \
        EXC(2b,3b,$31,%1)                                       \
        :       "=&r" (oldval), "=&r"(ret)                      \
        :       "r" (uaddr), "r"(oparg)                         \
        :       "memory")

static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
                u32 __user *uaddr)
{
        int oldval = 0, ret;

        if (!access_ok(uaddr, sizeof(u32)))
                return -EFAULT;

        switch (op) {
        case FUTEX_OP_SET:
                __futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ADD:
                __futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_OR:
                __futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ANDN:
                __futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_XOR:
                __futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
                break;
        default:
                ret = -ENOSYS;
        }

        if (!ret)
                *oval = oldval;

        return ret;
}

static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
                              u32 oldval, u32 newval)
{
        int ret = 0, cmp;
        u32 prev;

        if (!access_ok(uaddr, sizeof(u32)))
                return -EFAULT;

        __asm__ __volatile__ (
                __ASM_SMP_MB
        "1:     ldl_l   %1,0(%3)\n"
        "       cmpeq   %1,%4,%2\n"
        "       beq     %2,3f\n"
        "       mov     %5,%2\n"
        "2:     stl_c   %2,0(%3)\n"
        "       beq     %2,4f\n"
        "3:     .subsection 2\n"
        "4:     br      1b\n"
        "       .previous\n"
        EXC(1b,3b,$31,%0)
        EXC(2b,3b,$31,%0)
        :       "+r"(ret), "=&r"(prev), "=&r"(cmp)
        :       "r"(uaddr), "r"((long)(int)oldval), "r"(newval)
        :       "memory");

        *uval = prev;
        return ret;
}

#endif /* __KERNEL__ */
#endif /* _ASM_ALPHA_FUTEX_H */