11.3Sskrll/* $NetBSD: _lwp.c,v 1.3 2018/11/21 21:24:42 skrll Exp $ */
21.1Smatt
31.1Smatt/*-
41.1Smatt * Copyright (c) 2014 The NetBSD Foundation, Inc.
51.1Smatt * All rights reserved.
61.1Smatt *
71.1Smatt * This code is derived from software contributed to The NetBSD Foundation
81.1Smatt * by Matt Thomas of 3am Software Foundry.
91.1Smatt *
101.1Smatt * Redistribution and use in source and binary forms, with or without
111.1Smatt * modification, are permitted provided that the following conditions
121.1Smatt * are met:
131.1Smatt * 1. Redistributions of source code must retain the above copyright
141.1Smatt *    notice, this list of conditions and the following disclaimer.
151.1Smatt * 2. Redistributions in binary form must reproduce the above copyright
161.1Smatt *    notice, this list of conditions and the following disclaimer in the
171.1Smatt *    documentation and/or other materials provided with the distribution.
181.1Smatt *
191.1Smatt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
201.1Smatt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
211.1Smatt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
221.1Smatt * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
231.1Smatt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
241.1Smatt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
251.1Smatt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
261.1Smatt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
271.1Smatt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
281.1Smatt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
291.1Smatt * POSSIBILITY OF SUCH DAMAGE.
301.1Smatt */
311.1Smatt
321.1Smatt#include <sys/cdefs.h>
331.1Smatt#if defined(LIBC_SCCS) && !defined(lint)
341.3Sskrll__RCSID("$NetBSD: _lwp.c,v 1.3 2018/11/21 21:24:42 skrll Exp $");
351.1Smatt#endif /* LIBC_SCCS and not lint */
361.1Smatt
371.1Smatt#include "namespace.h"
381.1Smatt#include <sys/types.h>
391.1Smatt#include <ucontext.h>
401.1Smatt#include <lwp.h>
411.1Smatt#include <stdlib.h>
421.1Smatt
431.1Smattvoid
441.1Smatt_lwp_makecontext(ucontext_t *u, void (*start)(void *),
451.1Smatt    void *arg, void *private, caddr_t stack_base, size_t stack_size)
461.1Smatt{
471.1Smatt	getcontext(u);
481.1Smatt	u->uc_link = NULL;
491.1Smatt
501.1Smatt	u->uc_stack.ss_sp = stack_base;
511.1Smatt	u->uc_stack.ss_size = stack_size;
521.1Smatt
531.1Smatt	uintptr_t sp = (uintptr_t)stack_base + stack_size;
541.1Smatt
551.1Smatt	/*
561.1Smatt	 * Note: We make sure the stack is 16-byte aligned, here.
571.1Smatt	 */
581.1Smatt
591.1Smatt	u->uc_mcontext.__gregs[_REG_X0] = (__greg_t)(uintptr_t)arg;
601.1Smatt	u->uc_mcontext.__gregs[_REG_SP] = ((__greg_t)sp) & -16;
611.3Sskrll	u->uc_mcontext.__gregs[_REG_LR] = (__greg_t)(uintptr_t)_lwp_exit;
621.1Smatt	u->uc_mcontext.__gregs[_REG_PC] = (__greg_t)(uintptr_t)start;
631.1Smatt	u->uc_mcontext.__gregs[_REG_TPIDR] = (__greg_t)(uintptr_t)private;
641.2Sryo	u->uc_flags |= _UC_TLSBASE;
651.1Smatt}
66