1 /* Definition for thread-local data handling. NPTL/MIPS version.
2 Copyright (C) 2005-2023 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 /* Get system call information. */
31 # include <sysdep.h>
32
33 #ifdef __mips16
34 /* MIPS16 uses GCC builtin to access the TP. */
35 # define READ_THREAD_POINTER() (__builtin_thread_pointer ())
36 #else
37 /* Note: rd must be $v1 to be ABI-conformant. */
38 # if defined (__mips_isa_rev) && __mips_isa_rev >= 2
39 # define READ_THREAD_POINTER() \
40 ({ void *__result; \
41 asm volatile ("rdhwr\t%0, $29" : "=v" (__result)); \
42 __result; })
43 # else
44 # define READ_THREAD_POINTER() \
45 ({ void *__result; \
46 asm volatile (".set\tpush\n\t.set\tmips32r2\n\t" \
47 "rdhwr\t%0, $29\n\t.set\tpop" : "=v" (__result)); \
48 __result; })
49 # endif
50 #endif
51
52 #else /* __ASSEMBLER__ */
53 # if __mips_isa_rev >= 2
54 # define READ_THREAD_POINTER(rd) rdhwr rd, $29
55 # else
56 # define READ_THREAD_POINTER(rd) \
57 .set push; \
58 .set mips32r2; \
59 rdhwr rd, $29; \
60 .set pop
61 # endif
62 #endif /* __ASSEMBLER__ */
63
64
65 #ifndef __ASSEMBLER__
66
67 /* The TP points to the start of the thread blocks. */
68 # define TLS_DTV_AT_TP 1
69 # define TLS_TCB_AT_TP 0
70
71 /* Get the thread descriptor definition. */
72 # include <nptl/descr.h>
73
74 typedef struct
75 {
76 dtv_t *dtv;
77 void *private;
78 } tcbhead_t;
79
80 /* This is the size of the initial TCB. Because our TCB is before the thread
81 pointer, we don't need this. */
82 # define TLS_INIT_TCB_SIZE 0
83
84 /* This is the size of the TCB. Because our TCB is before the thread
85 pointer, we don't need this. */
86 # define TLS_TCB_SIZE 0
87
88 /* This is the size we need before TCB - actually, it includes the TCB. */
89 # define TLS_PRE_TCB_SIZE \
90 (sizeof (struct pthread) \
91 + ((sizeof (tcbhead_t) + __alignof (struct pthread) - 1) \
92 & ~(__alignof (struct pthread) - 1)))
93
94 /* The thread pointer (in hardware register $29) points to the end of
95 the TCB + 0x7000, as for PowerPC. The pthread_descr structure is
96 immediately in front of the TCB. */
97 # define TLS_TCB_OFFSET 0x7000
98
99 /* Install the dtv pointer. The pointer passed is to the element with
100 index -1 which contain the length. */
101 # define INSTALL_DTV(tcbp, dtvp) \
102 (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1)
103
104 /* Install new dtv for current thread. */
105 # define INSTALL_NEW_DTV(dtv) \
106 (THREAD_DTV() = (dtv))
107
108 /* Return dtv of given thread descriptor. */
109 # define GET_DTV(tcbp) \
110 (((tcbhead_t *) (tcbp))[-1].dtv)
111
112 /* Code to initially initialize the thread pointer. This might need
113 special attention since 'errno' is not yet available and if the
114 operation can cause a failure 'errno' must not be touched. */
115 # define TLS_INIT_TP(tcbp) \
116 ({ long int result_var; \
117 result_var = INTERNAL_SYSCALL_CALL (set_thread_area, \
118 (char *) (tcbp) + TLS_TCB_OFFSET); \
119 !INTERNAL_SYSCALL_ERROR_P (result_var); })
120
121 /* Value passed to 'clone' for initialization of the thread register. */
122 # define TLS_DEFINE_INIT_TP(tp, pd) \
123 void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
124
125 /* Return the address of the dtv for the current thread. */
126 # define THREAD_DTV() \
127 (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
128
129 /* Return the thread descriptor for the current thread. */
130 # define THREAD_SELF \
131 ((struct pthread *) (READ_THREAD_POINTER () \
132 - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
133
134 /* Magic for libthread_db to know how to do THREAD_SELF. */
135 # define DB_THREAD_SELF \
136 CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
137
138 /* Access to data in the thread descriptor is easy. */
139 # include <tcb-access.h>
140
141 /* l_tls_offset == 0 is perfectly valid on MIPS, so we have to use some
142 different value to mean unset l_tls_offset. */
143 # define NO_TLS_OFFSET -1
144
145 /* Get and set the global scope generation counter in struct pthread. */
146 #define THREAD_GSCOPE_FLAG_UNUSED 0
147 #define THREAD_GSCOPE_FLAG_USED 1
148 #define THREAD_GSCOPE_FLAG_WAIT 2
149 #define THREAD_GSCOPE_RESET_FLAG() \
150 do \
151 { int __res \
152 = atomic_exchange_release (&THREAD_SELF->header.gscope_flag, \
153 THREAD_GSCOPE_FLAG_UNUSED); \
154 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
155 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
156 } \
157 while (0)
158 #define THREAD_GSCOPE_SET_FLAG() \
159 do \
160 { \
161 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
162 atomic_write_barrier (); \
163 } \
164 while (0)
165
166 #endif /* __ASSEMBLER__ */
167
168 #endif /* tls.h */