freebsd-dev/lib/libc/mips/gen/_get_tp.c
Konstantin Belousov 06d8a116bd libc: add _get_tp() private function
which returns pointer to tcb

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D29623
2021-04-09 23:46:24 +03:00

104 lines
2.8 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2021 The FreeBSD Foundation
*
* This software were developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <string.h>
#include <stdint.h>
#include <machine/sysarch.h>
#include <machine/tls.h>
#include "libc_private.h"
#ifdef __mips_n64
static void *
_mips_get_tls(void)
{
uint64_t _rv;
__asm__ __volatile__ (
".set\tpush\n\t"
".set\tmips64r2\n\t"
"rdhwr\t%0, $29\n\t"
".set\tpop"
: "=r" (_rv));
/*
* XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
*
* Remove the offset since this really a request to get the TLS
* pointer via sysarch() (in theory). Of course, this may go away
* once the TLS code is rewritten.
*/
_rv = _rv - TLS_TP_OFFSET - TLS_TCB_SIZE;
return (void *)_rv;
}
#else /* mips 32 */
static void *
_mips_get_tls(void)
{
uint32_t _rv;
__asm__ __volatile__ (
".set\tpush\n\t"
".set\tmips32r2\n\t"
"rdhwr\t%0, $29\n\t"
".set\tpop"
: "=r" (_rv));
/*
* XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
*
* Remove the offset since this really a request to get the TLS
* pointer via sysarch() (in theory). Of course, this may go away
* once the TLS code is rewritten.
*/
_rv = _rv - TLS_TP_OFFSET - TLS_TCB_SIZE;
return (void *)_rv;
}
#endif /* ! __mips_n64 */
void *
_get_tp(void)
{
void *res;
#ifdef TLS_USE_SYSARCH
sysarch(MIPS_GET_TLS, &res);
#else
res = _mips_get_tls();
#endif
return (res);
}