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

#ifdef __KERNEL__

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

#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
({                                                              \
        __asm__ __volatile__ (                                  \
                "1:     l.lwa   %0, %2                  \n"     \
                        insn                            "\n"    \
                "2:     l.swa   %2, %1                  \n"     \
                "       l.bnf   1b                      \n"     \
                "        l.ori  %1, r0, 0               \n"     \
                "3:                                     \n"     \
                ".section .fixup,\"ax\"                 \n"     \
                "4:     l.j     3b                      \n"     \
                "        l.addi %1, r0, %3              \n"     \
                ".previous                              \n"     \
                ".section __ex_table,\"a\"              \n"     \
                ".word  1b,4b,2b,4b                     \n"     \
                ".previous                              \n"     \
                : "=&r" (oldval), "=&r" (ret), "+m" (*uaddr)    \
                : "i" (-EFAULT), "r" (oparg)                    \
                : "cc", "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("l.or %1,%4,%4", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ADD:
                __futex_atomic_op("l.add %1,%0,%4", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_OR:
                __futex_atomic_op("l.or %1,%0,%4", ret, oldval, uaddr, oparg);
                break;
        case FUTEX_OP_ANDN:
                __futex_atomic_op("l.and %1,%0,%4", ret, oldval, uaddr, ~oparg);
                break;
        case FUTEX_OP_XOR:
                __futex_atomic_op("l.xor %1,%0,%4", 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 prev;

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

        __asm__ __volatile__ (                          \
                "1:     l.lwa   %1, %2          \n"     \
                "       l.sfeq  %1, %3          \n"     \
                "       l.bnf   3f              \n"     \
                "        l.nop                  \n"     \
                "2:     l.swa   %2, %4          \n"     \
                "       l.bnf   1b              \n"     \
                "        l.nop                  \n"     \
                "3:                             \n"     \
                ".section .fixup,\"ax\"         \n"     \
                "4:     l.j     3b              \n"     \
                "        l.addi %0, r0, %5      \n"     \
                ".previous                      \n"     \
                ".section __ex_table,\"a\"      \n"     \
                ".word  1b,4b,2b,4b             \n"     \
                ".previous                      \n"     \
                : "+r" (ret), "=&r" (prev), "+m" (*uaddr) \
                : "r" (oldval), "r" (newval), "i" (-EFAULT) \
                : "cc", "memory"                        \
                );

        *uval = prev;
        return ret;
}

#endif /* __KERNEL__ */

#endif /* __ASM_OPENRISC_FUTEX_H */