/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __ASM_CSKY_FUTEX_H
#define __ASM_CSKY_FUTEX_H

#ifndef CONFIG_SMP
#include <asm-generic/futex.h>
#else
#include <linux/atomic.h>
#include <linux/futex.h>
#include <linux/uaccess.h>
#include <linux/errno.h>

#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)              \
{                                                                       \
        u32 tmp;                                                        \
                                                                        \
        __atomic_pre_full_fence();                                      \
                                                                        \
        __asm__ __volatile__ (                                          \
        "1:     ldex.w  %[ov], %[u]                     \n"             \
        "       "insn"                                  \n"             \
        "2:     stex.w  %[t], %[u]                      \n"             \
        "       bez     %[t], 1b                        \n"             \
        "       br      4f                              \n"             \
        "3:     mov     %[r], %[e]                      \n"             \
        "4:                                             \n"             \
        "       .section __ex_table,\"a\"               \n"             \
        "       .balign 4                               \n"             \
        "       .long   1b, 3b                          \n"             \
        "       .long   2b, 3b                          \n"             \
        "       .previous                               \n"             \
        : [r] "+r" (ret), [ov] "=&r" (oldval),                          \
          [u] "+m" (*uaddr), [t] "=&r" (tmp)                            \
        : [op] "Jr" (oparg), [e] "jr" (-EFAULT)                         \
        : "memory");                                                    \
                                                                        \
        __atomic_post_full_fence();                                     \
}

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

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

        switch (op) {
        case FUTEX_OP_SET:
                __futex_atomic_op("mov %[t], %[ov]",
                                  ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ADD:
                __futex_atomic_op("add %[t], %[ov], %[op]",
                                  ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_OR:
                __futex_atomic_op("or %[t], %[ov], %[op]",
                                  ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ANDN:
                __futex_atomic_op("and %[t], %[ov], %[op]",
                                  ret, oldval, uaddr, ~oparg);
                break;
        case FUTEX_OP_XOR:
                __futex_atomic_op("xor %[t], %[ov], %[op]",
                                  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;
        u32 val, tmp;

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

        __atomic_pre_full_fence();

        __asm__ __volatile__ (
        "1:     ldex.w  %[v], %[u]                      \n"
        "       cmpne   %[v], %[ov]                     \n"
        "       bt      4f                              \n"
        "       mov     %[t], %[nv]                     \n"
        "2:     stex.w  %[t], %[u]                      \n"
        "       bez     %[t], 1b                        \n"
        "       br      4f                              \n"
        "3:     mov     %[r], %[e]                      \n"
        "4:                                             \n"
        "       .section __ex_table,\"a\"               \n"
        "       .balign 4                               \n"
        "       .long   1b, 3b                          \n"
        "       .long   2b, 3b                          \n"
        "       .previous                               \n"
        : [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr),
          [t] "=&r" (tmp)
        : [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "Jr" (-EFAULT)
        : "memory");

        __atomic_post_full_fence();

        *uval = val;
        return ret;
}

#endif /* CONFIG_SMP */
#endif /* __ASM_CSKY_FUTEX_H */