/*      $NetBSD: SYS.h,v 1.5 2023/05/19 06:41:41 skrll Exp $ */

/*-
 * Copyright (c) 2014,2022 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Matt Thomas of 3am Software Foundry, and Nick Hudson.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/syscall.h>
#include <machine/asm.h>

#define SYSTRAP(x)                                                      \
        li      t6, SYS_ ## x;                                          \
        ecall

#define JUMP_TO_CERROR()                                                \
        .option push                                                    ;\
        .option norelax                                                 ;\
        tail    _C_LABEL(__cerror)                                      ;\
        .option pop

#define SYSTRAP_NOERROR(x)                                              \
        SYSTRAP(x)                                                      ;\
        nop; nop                /* size of ...                  */      ;\
        nop; nop                /*     JUMP_TO_CERROR           */      ;\

/*
 * Do a syscall that cannot fail (sync, get{p,u,g,eu,eg)id)
 */
#define RSYSCALL_NOERROR(x)                                             \
        PSEUDO_NOERROR(x,x)

/*
 * Do a normal syscall.
 */
#define RSYSCALL(x)                                                     \
        PSEUDO(x,x)

/*
 * Do a syscall that has an internal name and a weak external alias.
 */
#define WSYSCALL(weak,strong)                                           \
        WEAK_ALIAS(weak,strong)                                         ;\
        PSEUDO(strong,weak)

/*
 * Do a renamed or pseudo syscall (e.g., _exit()), where the entrypoint
 * and syscall name are not the same.
 */
#define PSEUDO_NOERROR(x,y)                                             \
ENTRY(x)                                                                ;\
        SYSTRAP_NOERROR(y)                                              ;\
        ret                     /* success */                           ;\
END(x)

#define PSEUDO(x,y)                                                     \
ENTRY(x)                                                                ;\
        SYSTRAP(y)                                                      ;\
        JUMP_TO_CERROR()        /* error */                             ;\
        ret                     /* success */                           ;\
END(x)