/* $NetBSD: swapcontext.S,v 1.12 2015/04/06 01:50:46 uwe Exp $ */ /*- * Copyright (c) 2001 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Klaus Klein. * * 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 #if defined(SYSLIBC_SCCS) && !defined(lint) RCSID("$NetBSD: swapcontext.S,v 1.12 2015/04/06 01:50:46 uwe Exp $") #endif /* SYSLIBC_SCCS and not lint */ /* * int * swapcontext(ucontext_t * restrict oucp, ucontext_t * restrict ucp); */ ENTRY(swapcontext) PIC_PROLOGUE(.L_got) sts.l pr, @-sp mov.l .L__getcontext, r0 mov.l r5, @-sp 1: CALL r0 ! _getcontext(oucp) mov.l r4, @-sp !! getcontext captures oucp resuming here with r12 (when PIC), !! pr, r5 and r4 pushed onto the stack tst r0, r0 bf.s 3f ! return error from getcontext mov.l @sp, r1 ! saved oucp !! adjust oucp to resume after setcontext below mova 3f, r0 mov.l r0, @(36 + 1 * 4, r1) ! _UC_MACHINE_SET_PC(oucp, pr) mov.l .L_setcontext, r2 2: CALL r2 ! setcontext(ucp) mov.l @(4, sp), r4 ! saved ucp .align 2 3: !! we get here on errors and when resuming oucp add #8, sp ! skip r4 and r5 lds.l @sp+, pr rts PIC_EPILOGUE_SLOT .align 2 .L_got: PIC_GOT_DATUM .L__getcontext: CALL_DATUM(_C_LABEL(_getcontext), 1b) .L_setcontext: CALL_DATUM(_C_LABEL(setcontext), 2b) SET_ENTRY_SIZE(swapcontext)