/* Modify saved context.

   Copyright (C) 2015-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#include "ucontext_i.h"

/* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */

	.text

ENTRY(__swapcontext)

	/* Same as getcontext().  */

	stw	r16, (UCONTEXT_MCONTEXT + 16*4)(r4)

	stw	r17, (UCONTEXT_MCONTEXT + 17*4)(r4)

	stw	r18, (UCONTEXT_MCONTEXT + 18*4)(r4)

	stw	r19, (UCONTEXT_MCONTEXT + 19*4)(r4)

	stw	r20, (UCONTEXT_MCONTEXT + 20*4)(r4)

	stw	r21, (UCONTEXT_MCONTEXT + 21*4)(r4)

	stw	r22, (UCONTEXT_MCONTEXT + 22*4)(r4)

	stw	ra,  (UCONTEXT_MCONTEXT + 24*4)(r4)

	stw	fp,  (UCONTEXT_MCONTEXT + 25*4)(r4)

	stw	gp,  (UCONTEXT_MCONTEXT + 26*4)(r4)

	/* Store return address at place for EA.  */

	stw	ra,  (UCONTEXT_MCONTEXT + 28*4)(r4)

	stw	sp,  (UCONTEXT_MCONTEXT + 29*4)(r4)

	/* Store zero for return success.  */

	stw	zero, (UCONTEXT_MCONTEXT + 2*4)(r4)

	/* Store value "1" at uc_flags to recognize as getcontext created.  */

	movi	r2, 1

	stw	r2, UCONTEXT_FLAGS(r4)

	/* Store MCONTEXT_VERSION at first word of mcontext_t.  */

	movi	r2, MCONTEXT_VERSION

	stw	r2, UCONTEXT_MCONTEXT(r4)

	/* Save ucp to non-argument syscall preserved register.  */

	mov	r10, r5

	/* Get signal mask.  */

	/* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */

	movi	r7, _NSIG8

	addi	r6, r4, UCONTEXT_SIGMASK

	mov	r5, zero

	movi	r4, SIG_BLOCK

	movi	r2, SYS_ify (rt_sigprocmask)

	trap

	bne	r7, zero, SYSCALL_ERROR_LABEL

	/* Same as setcontext().  */

	ldw	r5, UCONTEXT_FLAGS(r10)

	movi	r6, 1

	bne	r5, r6, .Lsigreturn

	/* Restore signal mask.  */

	/* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, NULL, _NSIG8) */

	movi	r7, _NSIG8

	addi	r5, r10, UCONTEXT_SIGMASK

	mov	r6, zero

	movi	r4, SIG_SETMASK

	movi	r2, SYS_ify (rt_sigprocmask)

	trap

	bne	r7, zero, SYSCALL_ERROR_LABEL

	/* Restore argument registers, for the makecontext() case.  */

	ldw	r4,   (UCONTEXT_MCONTEXT + 4*4)(r10)

	ldw	r5,   (UCONTEXT_MCONTEXT + 5*4)(r10)

	ldw	r6,   (UCONTEXT_MCONTEXT + 6*4)(r10)

	ldw	r7,   (UCONTEXT_MCONTEXT + 7*4)(r10)

	ldw	r16, (UCONTEXT_MCONTEXT + 16*4)(r10)

	ldw	r17, (UCONTEXT_MCONTEXT + 17*4)(r10)

	ldw	r18, (UCONTEXT_MCONTEXT + 18*4)(r10)

	ldw	r19, (UCONTEXT_MCONTEXT + 19*4)(r10)

	ldw	r20, (UCONTEXT_MCONTEXT + 20*4)(r10)

	ldw	r21, (UCONTEXT_MCONTEXT + 21*4)(r10)

	ldw	r22, (UCONTEXT_MCONTEXT + 22*4)(r10)

	ldw	ra,  (UCONTEXT_MCONTEXT + 24*4)(r10)

	ldw	fp,  (UCONTEXT_MCONTEXT + 25*4)(r10)

	ldw	gp,  (UCONTEXT_MCONTEXT + 26*4)(r10)

	/* Load address to continue execution.  */

	ldw	r3,  (UCONTEXT_MCONTEXT + 28*4)(r10)

	ldw	sp,  (UCONTEXT_MCONTEXT + 29*4)(r10)

	mov	r2, zero

	jmp	r3

.Lsigreturn:

	addi	sp, sp, -RT_SIGFRAME_SIZE

	cfi_adjust_cfa_offset (RT_SIGFRAME_SIZE)

	addi	r2, sp, RT_SIGFRAME_UCONTEXT

	movi	r3, UCONTEXT_SIZE-4

1:

	add	r6, r4, r3

	ldw	r5, 0(r6)

	add	r7, r2, r3

	addi	r3, r3, -4

	stw	r5, 0(r7)

	bgt	r3, zero, 1b

	movi	r2, SYS_ify (rt_sigreturn)

	trap

	addi	sp, sp, RT_SIGFRAME_SIZE

	cfi_adjust_cfa_offset (-RT_SIGFRAME_SIZE)

	br	SYSCALL_ERROR_LABEL

PSEUDO_END (__swapcontext)

weak_alias (__swapcontext, swapcontext)