11.14Sriastrad/*	$NetBSD: _resumecontext.S,v 1.14 2025/04/25 00:08:38 riastradh Exp $	*/
21.2Sthorpej
31.2Sthorpej/*-
41.2Sthorpej * Copyright (c) 2001 The NetBSD Foundation, Inc.
51.2Sthorpej * All rights reserved.
61.2Sthorpej *
71.2Sthorpej * This code is derived from software contributed to The NetBSD Foundation
81.2Sthorpej * by Wayne Knowles.
91.2Sthorpej *
101.2Sthorpej * Redistribution and use in source and binary forms, with or without
111.2Sthorpej * modification, are permitted provided that the following conditions
121.2Sthorpej * are met:
131.2Sthorpej * 1. Redistributions of source code must retain the above copyright
141.2Sthorpej *    notice, this list of conditions and the following disclaimer.
151.2Sthorpej * 2. Redistributions in binary form must reproduce the above copyright
161.2Sthorpej *    notice, this list of conditions and the following disclaimer in the
171.2Sthorpej *    documentation and/or other materials provided with the distribution.
181.2Sthorpej *
191.2Sthorpej * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
201.2Sthorpej * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
211.2Sthorpej * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
221.2Sthorpej * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
231.2Sthorpej * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
241.2Sthorpej * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
251.2Sthorpej * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
261.2Sthorpej * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
271.2Sthorpej * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
281.2Sthorpej * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
291.2Sthorpej * POSSIBILITY OF SUCH DAMAGE.
301.2Sthorpej */
311.2Sthorpej
321.6Smatt#include <machine/asm.h>
331.14Sriastrad#include <machine/param.h>
341.6Smatt
351.2Sthorpej#include "SYS.h"
361.6Smatt#include "assym.h"
371.2Sthorpej
381.2Sthorpej#if defined(SYSLIBC_SCCS) && !defined(lint)
391.14Sriastrad	RCSID("$NetBSD: _resumecontext.S,v 1.14 2025/04/25 00:08:38 riastradh Exp $")
401.2Sthorpej#endif /* SYSLIBC_SCCS && !lint */
411.2Sthorpej
421.2Sthorpej	.set	reorder
431.6Smatt	.hidden	_C_LABEL(__resumecontext)
441.8Sskrll
451.14Sriastrad#define	UCONTEXT_SIZE_ALIGNED						\
461.14Sriastrad	(((UCONTEXT_SIZE + STACK_ALIGNBYTES)/(STACK_ALIGNBYTES + 1))	\
471.14Sriastrad	    * (STACK_ALIGNBYTES + 1))
481.14Sriastrad
491.2SthorpejLEAF_NOPROFILE(__resumecontext)
501.6Smatt	/*
511.6Smatt	 * We get here not by a call through $t9 but thru $ra after the
521.11Sskrll	 * function passed to makecontext returns.  Therefore, we need
531.11Sskrll	 * to recover gp from ra
541.6Smatt	 */
551.11Sskrll#if defined(__mips_o32) || defined(__mips_o64)
561.11Sskrll	.set push
571.11Sskrll	.set noreorder
581.11Sskrll	.cpload	ra
591.11Sskrll	.set pop
601.11Sskrll#endif
611.11Sskrll#if defined(__mips_n32) || defined(__mips_n64)
621.11Sskrll	.cpsetup ra, t3, __resumecontext
631.11Sskrll#endif
641.12Sskrll
651.14Sriastrad	PTR_SUBU	sp, sp, UCONTEXT_SIZE_ALIGNED	# get space for ucontext
661.6Smatt	move		a0, sp				# arg0 for getcontext
671.13Sskrll	PTR_S		zero, _UC_LINK(a0)		# make sure uc_link is 0
681.6Smatt	SYSTRAP(getcontext)				# get context
691.11Sskrll
701.11Sskrll#if defined(__mips_n32) || defined(__mips_n64)
711.11Sskrll	REG_PROLOGUE
721.11Sskrll	/* We saved gp in t2 above */
731.13Sskrll	REG_S		t3, _UC_GREGS_GP(a0)
741.11Sskrll	REG_EPILOGUE
751.11Sskrll#endif
761.11Sskrll
771.13Sskrll	PTR_L		a0, _UC_LINK(a0)		# linked context?
781.10Sskrll	NOP_L
791.6Smatt	beq		a0, zero, 1f			#   nope, exit process
801.6Smatt	nop
811.11Sskrll	PIC_TAILCALL(setcontext)			#   yes, become it.
821.6Smatt	/* NOTREACHED (in theory) */
831.8Sskrll	li		a0, -1				# failure,
841.6Smatt1:
851.6Smatt	SYSTRAP(exit)					# all hope is lost.
861.6Smatt	/* NOTREACHED */
871.2SthorpejEND(__resumecontext)
88