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1/* Definition for thread-local data handling.
2 Copyright (C) 2022-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library. If not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _LOONGARCH_TLS_H
20#define _LOONGARCH_TLS_H 1
21
22#include <dl-sysdep.h>
23
24#ifndef __ASSEMBLER__
25#include <stdbool.h>
26#include <stddef.h>
27#include <stdint.h>
28#include <dl-dtv.h>
29
30register void *__thread_self asm ("$tp");
31#define READ_THREAD_POINTER() ({ __thread_self; })
32
33/* Get system call information. */
34#include <sysdep.h>
35
36/* The TP points to the start of the thread blocks. */
37#define TLS_DTV_AT_TP 1
38#define TLS_TCB_AT_TP 0
39
40/* Get the thread descriptor definition. */
41#include <nptl/descr.h>
42
43typedef struct
44{
45 dtv_t *dtv;
46 void *private;
47} tcbhead_t;
48
49/* This is the size of the initial TCB. Because our TCB is before the thread
50 pointer, we don't need this. */
51#define TLS_INIT_TCB_SIZE 0
52
53/* Alignment requirements for the initial TCB. */
54#define TLS_INIT_TCB_ALIGN __alignof__(struct pthread)
55
56/* This is the size of the TCB. Because our TCB is before the thread
57 pointer, we don't need this. */
58#define TLS_TCB_SIZE 0
59
60/* Alignment requirements for the TCB. */
61#define TLS_TCB_ALIGN __alignof__(struct pthread)
62
63/* This is the size we need before TCB - actually, it includes the TCB. */
64#define TLS_PRE_TCB_SIZE \
65 (sizeof (struct pthread) \
66 + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
67
68/* The thread pointer tp points to the end of the TCB.
69 The pthread_descr structure is immediately in front of the TCB. */
70#define TLS_TCB_OFFSET 0
71
72/* Install the dtv pointer. The pointer passed is to the element with
73 index -1 which contain the length. */
74#define INSTALL_DTV(tcbp, dtvp) (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1)
75
76/* Install new dtv for current thread. */
77#define INSTALL_NEW_DTV(dtv) (THREAD_DTV () = (dtv))
78
79/* Return dtv of given thread descriptor. */
80#define GET_DTV(tcbp) (((tcbhead_t *) (tcbp))[-1].dtv)
81
82/* Code to initially initialize the thread pointer. */
83#define TLS_INIT_TP(tcbp) \
84 ({ \
85 __thread_self = (char *) tcbp + TLS_TCB_OFFSET; \
86 true; \
87 })
88
89/* Return the address of the dtv for the current thread. */
90#define THREAD_DTV() \
91 (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
92
93/* Return the thread descriptor for the current thread. */
94#define THREAD_SELF \
95 ((struct pthread *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET \
96 - TLS_PRE_TCB_SIZE))
97
98/* Value passed to 'clone' for initialization of the thread register. */
99#define TLS_DEFINE_INIT_TP(tp, pd) \
100 void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
101
102/* Informs libthread_db that the thread pointer is register 2, which is used
103 * to know how to do THREAD_SELF. */
104#define DB_THREAD_SELF \
105 REGISTER (64, 64, 2 * 8, -TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
106
107/* Access to data in the thread descriptor is easy. */
108# include <tcb-access.h>
109
110/* l_tls_offset == 0 is perfectly valid, so we have to use some different
111 value to mean unset l_tls_offset. */
112#define NO_TLS_OFFSET -1
113
114/* Get and set the global scope generation counter in struct pthread. */
115#define THREAD_GSCOPE_IN_TCB 1
116#define THREAD_GSCOPE_FLAG_UNUSED 0
117#define THREAD_GSCOPE_FLAG_USED 1
118#define THREAD_GSCOPE_FLAG_WAIT 2
119#define THREAD_GSCOPE_RESET_FLAG() \
120 do \
121 { \
122 int __res = atomic_exchange_release (&THREAD_SELF->header.gscope_flag, \
123 THREAD_GSCOPE_FLAG_UNUSED); \
124 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
125 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
126 } \
127 while (0)
128#define THREAD_GSCOPE_SET_FLAG() \
129 do \
130 { \
131 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
132 atomic_write_barrier (); \
133 } \
134 while (0)
135
136#endif /* __ASSEMBLER__ */
137
138#endif /* tls.h */
139

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source code of glibc/sysdeps/loongarch/nptl/tls.h