1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2021 The FreeBSD Foundation
5 *
6 * This software were developed by Konstantin Belousov
7 * under sponsorship from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD$");
33
34#include <sys/types.h>
35#include <string.h>
36#include <stdint.h>
37#include <machine/sysarch.h>
38#include <machine/tls.h>
39
40#include "libc_private.h"
41
42#ifdef __mips_n64
43static void *
44_mips_get_tls(void)
45{
46	uint64_t _rv;
47
48	__asm__ __volatile__ (
49	    ".set\tpush\n\t"
50	    ".set\tmips64r2\n\t"
51	    "rdhwr\t%0, $29\n\t"
52	    ".set\tpop"
53	    : "=r" (_rv));
54	/*
55	 * XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
56	 *
57	 * Remove the offset since this really a request to get the TLS
58	 * pointer via sysarch() (in theory).  Of course, this may go away
59	 * once the TLS code is rewritten.
60	 */
61	_rv = _rv - TLS_TP_OFFSET - TLS_TCB_SIZE;
62
63	return (void *)_rv;
64}
65
66#else /* mips 32 */
67
68static void *
69_mips_get_tls(void)
70{
71	uint32_t _rv;
72
73	__asm__ __volatile__ (
74	    ".set\tpush\n\t"
75	    ".set\tmips32r2\n\t"
76	    "rdhwr\t%0, $29\n\t"
77	    ".set\tpop"
78	    : "=r" (_rv));
79	/*
80	 * XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
81	 *
82	 * Remove the offset since this really a request to get the TLS
83	 * pointer via sysarch() (in theory).  Of course, this may go away
84	 * once the TLS code is rewritten.
85	 */
86	_rv = _rv - TLS_TP_OFFSET - TLS_TCB_SIZE;
87
88	return (void *)_rv;
89}
90#endif /* ! __mips_n64 */
91
92void *
93_get_tp(void)
94{
95	void *res;
96
97#ifdef TLS_USE_SYSARCH
98	sysarch(MIPS_GET_TLS, &res);
99#else
100	res = _mips_get_tls();
101#endif
102	return (res);
103}
104