1/* $NetBSD: swapcontext.S,v 1.12 2015/04/06 01:50:46 uwe 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 Klaus Klein. 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 <machine/asm.h> 33#if defined(SYSLIBC_SCCS) && !defined(lint) 34 RCSID("$NetBSD: swapcontext.S,v 1.12 2015/04/06 01:50:46 uwe Exp $") 35#endif /* SYSLIBC_SCCS and not lint */ 36 37/* 38 * int 39 * swapcontext(ucontext_t * restrict oucp, ucontext_t * restrict ucp); 40 */ 41ENTRY(swapcontext) 42 PIC_PROLOGUE(.L_got) 43 sts.l pr, @-sp 44 45 mov.l .L__getcontext, r0 46 mov.l r5, @-sp 471: CALL r0 ! _getcontext(oucp) 48 mov.l r4, @-sp 49 !! getcontext captures oucp resuming here with r12 (when PIC), 50 !! pr, r5 and r4 pushed onto the stack 51 52 tst r0, r0 53 bf.s 3f ! return error from getcontext 54 mov.l @sp, r1 ! saved oucp 55 56 !! adjust oucp to resume after setcontext below 57 mova 3f, r0 58 mov.l r0, @(36 + 1 * 4, r1) ! _UC_MACHINE_SET_PC(oucp, pr) 59 60 mov.l .L_setcontext, r2 612: CALL r2 ! setcontext(ucp) 62 mov.l @(4, sp), r4 ! saved ucp 63 64 .align 2 653: !! we get here on errors and when resuming oucp 66 add #8, sp ! skip r4 and r5 67 lds.l @sp+, pr 68 rts 69 PIC_EPILOGUE_SLOT 70 71 .align 2 72.L_got: PIC_GOT_DATUM 73.L__getcontext: CALL_DATUM(_C_LABEL(_getcontext), 1b) 74.L_setcontext: CALL_DATUM(_C_LABEL(setcontext), 2b) 75 SET_ENTRY_SIZE(swapcontext) 76