lib/libc/arch/riscv/SYS.h

   1 /*      $NetBSD: SYS.h,v 1.2 2015/03/27 06:44:28 matt Exp $ */
   2
   3 /*-
   4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Matt Thomas of 3am Software Foundry.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include <sys/syscall.h>
  33 #include <machine/asm.h>
  34
  35 #define SYSTRAP(x)              li      t6,SYS_ ## x; scall
  36 #define JUMP_TO_CERROR()        j       _C_LABEL(__cerror)
  37
  38 /*
  39  * Do a syscall that cannot fail (sync, get{p,u,g,eu,eg)id)
  40  */
  41 #define RSYSCALL_NOERROR(x)                                             \
  42         PSEUDO_NOERROR(x,x)
  43
  44 /*
  45  * Do a normal syscall.
  46  */
  47 #define RSYSCALL(x)                                                     \
  48         PSEUDO(x,x)
  49
  50 /*
  51  * Do a syscall that has an internal name and a weak external alias.
  52  */
  53 #define WSYSCALL(weak,strong)                                           \
  54         WEAK_ALIAS(weak,strong)                                         ;\
  55         PSEUDO(strong,weak)
  56
  57 /*
  58  * Do a renamed or pseudo syscall (e.g., _exit()), where the entrypoint
  59  * and syscall name are not the same.
  60  */
  61 #define PSEUDO_NOERROR(x,y)                                             \
  62 ENTRY(x);                                                               ;\
  63         SYSTRAP(y)                                                      ;\
  64         ret     /* error */                                             ;\
  65         ret     /* success */                                           ;\
  66         END(x)
  67
  68 #define PSEUDO(x,y)                                                     \
  69 ENTRY(x);                                                               ;\
  70         SYSTRAP(y)                                                      ;\
  71         JUMP_TO_CERROR()        /* error */                             ;\
  72         ret                     /* success */                           ;\
  73         END(x)