lib/libc/arch/mips/gen/_lwp.c

   1 /*      $NetBSD: _lwp.c,v 1.8 2011/04/29 08:05:22 matt Exp $    */
   2
   3 /*
   4  * Copyright (c) 2001 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Wayne Knowles
   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/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 __RCSID("$NetBSD: _lwp.c,v 1.8 2011/04/29 08:05:22 matt Exp $");
  35 #endif /* LIBC_SCCS and not lint */
  36
  37 #include "namespace.h"
  38 #include <sys/types.h>
  39 #include <ucontext.h>
  40 #include <lwp.h>
  41 #include <stdlib.h>
  42
  43 #if defined(__mips_o32) || defined(__mips_o64)
  44 #define CALLFRAME_SIZ   (6 * sizeof(void *))
  45 #else
  46 #define CALLFRAME_SIZ   (4 * sizeof(uint64_t))
  47 #endif
  48
  49 void
  50 _lwp_makecontext(ucontext_t *u, void (*start)(void *),
  51         void *arg, void *tcb, caddr_t stack_base, size_t stack_size)
  52 {
  53         caddr_t sp;
  54         __greg_t *gr;
  55
  56         getcontext(u);
  57         gr = u->uc_mcontext.__gregs;
  58         u->uc_link = NULL;
  59
  60         u->uc_stack.ss_sp = stack_base;
  61         u->uc_stack.ss_size = stack_size;
  62         sp = stack_base + stack_size - CALLFRAME_SIZ;
  63
  64         gr[_REG_EPC] = (uintptr_t) start;
  65         gr[_REG_T9] = (uintptr_t) start; /* required for .abicalls */
  66         gr[_REG_RA] = (uintptr_t) _lwp_exit;
  67         gr[_REG_A0] = (uintptr_t) arg;
  68         gr[_REG_SP] = (uintptr_t) sp;
  69         u->uc_mcontext._mc_tlsbase =
  70             (uintptr_t)tcb + TLS_TP_OFFSET + sizeof(struct tls_tcb);
  71         u->uc_flags |= _UC_TLSBASE;
  72 }