1 /* Definition for thread-local data handling. NPTL/Nios II version.
2 Copyright (C) 2012-2023 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 _TLS_H
20 #define _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
30 #else /* __ASSEMBLER__ */
31 # include <tcb-offsets.h>
32 #endif /* __ASSEMBLER__ */
33
34
35 #ifndef __ASSEMBLER__
36
37 /* Get system call information. */
38 # include <sysdep.h>
39
40 /* The TP points to the start of the thread blocks. */
41 # define TLS_DTV_AT_TP 1
42 # define TLS_TCB_AT_TP 0
43
44 /* Get the thread descriptor definition. */
45 # include <nptl/descr.h>
46
47 typedef struct
48 {
49 dtv_t *dtv;
50 uintptr_t pointer_guard;
51 unsigned spare[6];
52 } tcbhead_t;
53
54 register struct pthread *__thread_self __asm__("r23");
55
56 #define READ_THREAD_POINTER() ((void *) __thread_self)
57
58 /* This is the size of the initial TCB. Because our TCB is before the thread
59 pointer, we don't need this. */
60 # define TLS_INIT_TCB_SIZE 0
61
62 /* This is the size of the TCB. Because our TCB is before the thread
63 pointer, we don't need this. */
64 # define TLS_TCB_SIZE 0
65
66 /* This is the size we need before TCB - actually, it includes the TCB. */
67 # define TLS_PRE_TCB_SIZE \
68 (sizeof (struct pthread) \
69 + ((sizeof (tcbhead_t) + __alignof (struct pthread) - 1) \
70 & ~(__alignof (struct pthread) - 1)))
71
72 /* The thread pointer (in hardware register r23) points to the end of
73 the TCB + 0x7000, as for PowerPC and MIPS. */
74 # define TLS_TCB_OFFSET 0x7000
75
76 /* Install the dtv pointer. The pointer passed is to the element with
77 index -1 which contain the length. */
78 # define INSTALL_DTV(tcbp, dtvp) \
79 (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1)
80
81 /* Install new dtv for current thread. */
82 # define INSTALL_NEW_DTV(dtv) \
83 (THREAD_DTV() = (dtv))
84
85 /* Return dtv of given thread descriptor. */
86 # define GET_DTV(tcbp) \
87 (((tcbhead_t *) (tcbp))[-1].dtv)
88
89 /* Code to initially initialize the thread pointer. */
90 # define TLS_INIT_TP(tcbp) \
91 (__thread_self = (struct pthread *) ((char *) tcbp + TLS_TCB_OFFSET), true)
92
93 /* Value passed to 'clone' for initialization of the thread register. */
94 # define TLS_DEFINE_INIT_TP(tp, pd) \
95 void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
96
97 /* Return the address of the dtv for the current thread. */
98 # define THREAD_DTV() \
99 (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
100
101 /* Return the thread descriptor for the current thread. */
102 # define THREAD_SELF \
103 ((struct pthread *) (READ_THREAD_POINTER () \
104 - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
105
106 /* Magic for libthread_db to know how to do THREAD_SELF. */
107 # define DB_THREAD_SELF \
108 REGISTER (32, 32, 23 * 4, -TLS_PRE_TCB_SIZE - TLS_TCB_OFFSET)
109
110 # include <tcb-access.h>
111
112 # define THREAD_GET_POINTER_GUARD() \
113 (((tcbhead_t *) (READ_THREAD_POINTER () \
114 - TLS_TCB_OFFSET))[-1].pointer_guard)
115 # define THREAD_SET_POINTER_GUARD(value) \
116 (THREAD_GET_POINTER_GUARD () = (value))
117 # define THREAD_COPY_POINTER_GUARD(descr) \
118 (((tcbhead_t *) ((void *) (descr) \
119 + TLS_PRE_TCB_SIZE))[-1].pointer_guard \
120 = THREAD_GET_POINTER_GUARD())
121
122 /* l_tls_offset == 0 is perfectly valid on Nios II, so we have to use some
123 different value to mean unset l_tls_offset. */
124 # define NO_TLS_OFFSET -1
125
126 /* Get and set the global scope generation counter in struct pthread. */
127 #define THREAD_GSCOPE_FLAG_UNUSED 0
128 #define THREAD_GSCOPE_FLAG_USED 1
129 #define THREAD_GSCOPE_FLAG_WAIT 2
130 #define THREAD_GSCOPE_RESET_FLAG() \
131 do \
132 { int __res \
133 = atomic_exchange_release (&THREAD_SELF->header.gscope_flag, \
134 THREAD_GSCOPE_FLAG_UNUSED); \
135 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
136 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
137 } \
138 while (0)
139 #define THREAD_GSCOPE_SET_FLAG() \
140 do \
141 { \
142 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
143 atomic_write_barrier (); \
144 } \
145 while (0)
146
147 #endif /* __ASSEMBLER__ */
148
149 #endif /* tls.h */