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/* Copyright (C) 2002-2024 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
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <features.h>
#include "ucontext_i.h"
/* __swapcontext (ucontext_t *oucp, const ucontext_t *ucp)
Saves the machine context in oucp such that when it is activated,
it appears as if __swapcontext() returned again, restores the
machine context in ucp and thereby resumes execution in that
context.
This implementation is intended to be used for *synchronous* context
switches only. Therefore, it does not have to save anything
other than the PRESERVED state. */
ENTRY(__swapcontext)
/* While not part of the ABI a system call never clobbers r0
or r1. So keeping the values here while calling
rt_sigprocmask is ok. */
lr %r1,%r2
lr %r0,%r3
/* Store fpu context. */
stfpc SC_FPC(%r1)
std %f0,SC_FPRS(%r1)
std %f1,SC_FPRS+8(%r1)
std %f2,SC_FPRS+16(%r1)
std %f3,SC_FPRS+24(%r1)
std %f4,SC_FPRS+32(%r1)
std %f5,SC_FPRS+40(%r1)
std %f6,SC_FPRS+48(%r1)
std %f7,SC_FPRS+56(%r1)
std %f8,SC_FPRS+64(%r1)
std %f9,SC_FPRS+72(%r1)
std %f10,SC_FPRS+80(%r1)
std %f11,SC_FPRS+88(%r1)
std %f12,SC_FPRS+96(%r1)
std %f13,SC_FPRS+104(%r1)
std %f14,SC_FPRS+112(%r1)
std %f15,SC_FPRS+120(%r1)
/* Set __swapcontext return value to 0. */
slr %r2,%r2
/* Store access registers. */
stam %a0,%a15,SC_ACRS(%r1)
/* Store general purpose registers. */
stm %r0,%r15,SC_GPRS(%r1)
/* Store psw mask to 0x0 and addr to return address. Then the address
can be retrieved from the ucontext structure in the same way as if it
is created by kernel and passed to a signal-handler. */
st %r2,SC_PSW+0(%r1)
st %r14,SC_PSW+4(%r1)
/* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, &oucp->uc_sigmask,
sigsetsize). */
la %r2,SIG_SETMASK
lr %r5,%r0
la %r3,SC_MASK(%r5)
la %r4,SC_MASK(%r1)
lhi %r5,_NSIG8
lhi %r1,SYS_ify(rt_sigprocmask)
svc 0
/* Load fpu context. */
lr %r5,%r0
lfpc SC_FPC(%r5)
ld %f0,SC_FPRS(%r5)
ld %f1,SC_FPRS+8(%r5)
ld %f2,SC_FPRS+16(%r5)
ld %f3,SC_FPRS+24(%r5)
ld %f4,SC_FPRS+32(%r5)
ld %f5,SC_FPRS+40(%r5)
ld %f6,SC_FPRS+48(%r5)
ld %f7,SC_FPRS+56(%r5)
ld %f8,SC_FPRS+64(%r5)
ld %f9,SC_FPRS+72(%r5)
ld %f10,SC_FPRS+80(%r5)
ld %f11,SC_FPRS+88(%r5)
ld %f12,SC_FPRS+96(%r5)
ld %f13,SC_FPRS+104(%r5)
ld %f14,SC_FPRS+112(%r5)
ld %f15,SC_FPRS+120(%r5)
/* Don't touch %a0, used for thread purposes. */
lam %a1,%a15,SC_ACRS+4(%r5)
/* Load general purpose registers. */
lm %r0,%r15,SC_GPRS(%r5)
/* Return. */
br %r14
END(__swapcontext)
weak_alias (__swapcontext, swapcontext)
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