xref: /titanic_44/usr/src/lib/libc/sparcv9/gen/swapctxt.c (revision 7257d1b4d25bfac0c802847390e98a464fd787ac)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
58cd45542Sraf  * Common Development and Distribution License (the "License").
68cd45542Sraf  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
210ec57554Sraf 
227c478bd9Sstevel@tonic-gate /*
238cd45542Sraf  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
267c478bd9Sstevel@tonic-gate 
278cd45542Sraf /*	Copyright (c) 1988 AT&T	*/
288cd45542Sraf /*	  All Rights Reserved  	*/
298cd45542Sraf 
307c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
317c478bd9Sstevel@tonic-gate 
32*7257d1b4Sraf #pragma weak _swapcontext = swapcontext
337c478bd9Sstevel@tonic-gate 
34*7257d1b4Sraf #include "lint.h"
350ec57554Sraf #include "thr_uberdata.h"
367c478bd9Sstevel@tonic-gate #include <ucontext.h>
377c478bd9Sstevel@tonic-gate #include <sys/types.h>
387c478bd9Sstevel@tonic-gate 
397c478bd9Sstevel@tonic-gate int
swapcontext(ucontext_t * oucp,const ucontext_t * nucp)407c478bd9Sstevel@tonic-gate swapcontext(ucontext_t *oucp, const ucontext_t *nucp)
417c478bd9Sstevel@tonic-gate {
427c478bd9Sstevel@tonic-gate 	greg_t *reg;
437c478bd9Sstevel@tonic-gate 
448cd45542Sraf 	if (__getcontext(oucp))
457c478bd9Sstevel@tonic-gate 		return (-1);
467c478bd9Sstevel@tonic-gate 
477c478bd9Sstevel@tonic-gate 	/*
487c478bd9Sstevel@tonic-gate 	 * Note that %o1 and %g1 are modified by the system call
497c478bd9Sstevel@tonic-gate 	 * routine. ABI calling conventions specify that the caller
507c478bd9Sstevel@tonic-gate 	 * can not depend upon %o0 thru %o5 nor g1, so no effort is
517c478bd9Sstevel@tonic-gate 	 * made to maintain these registers. %o0 is forced to reflect
527c478bd9Sstevel@tonic-gate 	 * an affirmative return code.
537c478bd9Sstevel@tonic-gate 	 */
547c478bd9Sstevel@tonic-gate 	reg = oucp->uc_mcontext.gregs;
557c478bd9Sstevel@tonic-gate 	reg[REG_SP] = getfp();
567c478bd9Sstevel@tonic-gate 	reg[REG_O7] = caller();
577c478bd9Sstevel@tonic-gate 	reg[REG_PC] = reg[REG_O7] + 8;
587c478bd9Sstevel@tonic-gate 	reg[REG_nPC] = reg[REG_PC] + 4;
597c478bd9Sstevel@tonic-gate 	reg[REG_O0] = 0;
607c478bd9Sstevel@tonic-gate 
617c478bd9Sstevel@tonic-gate 	return (setcontext((ucontext_t *)nucp));
627c478bd9Sstevel@tonic-gate }
63