1/* Copyright (C) 2002-2022 Free Software Foundation, Inc.
2   This file is part of the GNU C Library.
3
4   The GNU C Library is free software; you can redistribute it and/or
5   modify it under the terms of the GNU Lesser General Public
6   License as published by the Free Software Foundation; either
7   version 2.1 of the License, or (at your option) any later version.
8
9   The GNU C Library is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   Lesser General Public License for more details.
13
14   You should have received a copy of the GNU Lesser General Public
15   License along with the GNU C Library; if not, see
16   <https://www.gnu.org/licenses/>.  */
17
18#include <sysdep.h>
19#include <features.h>
20
21#include "ucontext_i.h"
22
23/*  __swapcontext (ucontext_t *oucp, const ucontext_t *ucp)
24
25  Saves the machine context in oucp such that when it is activated,
26  it appears as if __swapcontext() returned again, restores the
27  machine context in ucp and thereby resumes execution in that
28  context.
29
30  This implementation is intended to be used for *synchronous* context
31  switches only.  Therefore, it does not have to save anything
32  other than the PRESERVED state.  */
33
34ENTRY(__swapcontext)
35	/* While not part of the ABI a system call never clobbers r0
36	   or r1.  So keeping the values here while calling
37	   rt_sigprocmask is ok.  */
38	lgr	%r1,%r2
39	lgr     %r0,%r3
40
41	/* Store fpu context.  */
42	stfpc   SC_FPC(%r1)
43	std     %f0,SC_FPRS(%r1)
44	std     %f1,SC_FPRS+8(%r1)
45	std     %f2,SC_FPRS+16(%r1)
46	std     %f3,SC_FPRS+24(%r1)
47	std     %f4,SC_FPRS+32(%r1)
48	std     %f5,SC_FPRS+40(%r1)
49	std     %f6,SC_FPRS+48(%r1)
50	std     %f7,SC_FPRS+56(%r1)
51	std     %f8,SC_FPRS+64(%r1)
52	std     %f9,SC_FPRS+72(%r1)
53	std     %f10,SC_FPRS+80(%r1)
54	std     %f11,SC_FPRS+88(%r1)
55	std     %f12,SC_FPRS+96(%r1)
56	std     %f13,SC_FPRS+104(%r1)
57	std     %f14,SC_FPRS+112(%r1)
58	std     %f15,SC_FPRS+120(%r1)
59
60	/* Set __swapcontext return value to 0.  */
61	slgr     %r2,%r2
62
63	/* Store access registers.  */
64	stam    %a0,%a15,SC_ACRS(%r1)
65
66	/* Store general purpose registers.  */
67	stmg    %r0,%r15,SC_GPRS(%r1)
68
69	/* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, &oucp->uc_sigmask,
70	   sigsetsize).  */
71	la      %r2,SIG_SETMASK
72	lgr	%r5,%r0
73	la	%r3,SC_MASK(%r5)
74	la	%r4,SC_MASK(%r1)
75	lghi	%r5,_NSIG8
76	svc	SYS_ify(rt_sigprocmask)
77
78	/* Load fpu context.  */
79	lgr	%r5,%r0
80	lfpc	SC_FPC(%r5)
81	ld	%f0,SC_FPRS(%r5)
82	ld      %f1,SC_FPRS+8(%r5)
83	ld      %f2,SC_FPRS+16(%r5)
84	ld      %f3,SC_FPRS+24(%r5)
85	ld      %f4,SC_FPRS+32(%r5)
86	ld      %f5,SC_FPRS+40(%r5)
87	ld      %f6,SC_FPRS+48(%r5)
88	ld      %f7,SC_FPRS+56(%r5)
89	ld      %f8,SC_FPRS+64(%r5)
90	ld      %f9,SC_FPRS+72(%r5)
91	ld      %f10,SC_FPRS+80(%r5)
92	ld      %f11,SC_FPRS+88(%r5)
93	ld      %f12,SC_FPRS+96(%r5)
94	ld      %f13,SC_FPRS+104(%r5)
95	ld      %f14,SC_FPRS+112(%r5)
96	ld      %f15,SC_FPRS+120(%r5)
97
98	/* Don't touch %a0 and %a1, used for thread purposes.  */
99	lam     %a2,%a15,SC_ACRS+8(%r5)
100
101	/* Load general purpose registers.  */
102	lmg	%r0,%r15,SC_GPRS(%r5)
103
104	/* Return.  */
105	br	%r14
106END(__swapcontext)
107weak_alias (__swapcontext, swapcontext)
108