1 /* Definition for thread-local data handling. NPTL/m68k version.
2 Copyright (C) 2010-2023 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 #endif /* __ASSEMBLER__ */
30
31 #ifndef __ASSEMBLER__
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
43 typedef 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 /* This is the size of the TCB. Because our TCB is before the thread
54 pointer, we don't need this. */
55 # define TLS_TCB_SIZE 0
56
57 /* This is the size we need before TCB - actually, it includes the TCB. */
58 # define TLS_PRE_TCB_SIZE \
59 (sizeof (struct pthread) \
60 + ((sizeof (tcbhead_t) + __alignof (struct pthread) - 1) \
61 & ~(__alignof (struct pthread) - 1)))
62
63 /* The thread pointer (TP) points to the end of the
64 TCB + 0x7000, as for PowerPC and MIPS. This implies that TCB address is
65 TP - 0x7000. As we define TLS_DTV_AT_TP we can
66 assume that the pthread struct is allocated immediately ahead of the
67 TCB. This implies that the pthread_descr address is
68 TP - (TLS_PRE_TCB_SIZE + 0x7000). */
69 # define TLS_TCB_OFFSET 0x7000
70
71 /* Install the dtv pointer. The pointer passed is to the element with
72 index -1 which contain the length. */
73 # define INSTALL_DTV(tcbp, dtvp) \
74 ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
75
76 /* Install new dtv for current thread. */
77 # define INSTALL_NEW_DTV(dtv) \
78 (THREAD_DTV () = (dtv))
79
80 /* Return dtv of given thread descriptor. */
81 # define GET_DTV(tcbp) \
82 (((tcbhead_t *) (tcbp))[-1].dtv)
83
84 /* Code to initially initialize the thread pointer. This might need
85 special attention since 'errno' is not yet available and if the
86 operation can cause a failure 'errno' must not be touched. */
87 # define TLS_INIT_TP(tcbp) \
88 ({ \
89 int _sys_result; \
90 \
91 _sys_result = INTERNAL_SYSCALL_CALL (set_thread_area, \
92 ((void *) (tcbp)) + TLS_TCB_OFFSET); \
93 !INTERNAL_SYSCALL_ERROR_P (_sys_result); })
94
95 # define TLS_DEFINE_INIT_TP(tp, pd) \
96 void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
97
98 extern void * __m68k_read_tp (void);
99
100 /* Return the address of the dtv for the current thread. */
101 # define THREAD_DTV() \
102 (((tcbhead_t *) (__m68k_read_tp () - TLS_TCB_OFFSET))[-1].dtv)
103
104 /* Return the thread descriptor for the current thread. */
105 # define THREAD_SELF \
106 ((struct pthread *) (__m68k_read_tp () - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
107
108 /* Magic for libthread_db to know how to do THREAD_SELF. */
109 # define DB_THREAD_SELF \
110 CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
111
112 # include <tcb-access.h>
113
114 /* l_tls_offset == 0 is perfectly valid on M68K, so we have to use some
115 different value to mean unset l_tls_offset. */
116 # define NO_TLS_OFFSET -1
117
118 /* Get and set the global scope generation counter in struct pthread. */
119 #define THREAD_GSCOPE_FLAG_UNUSED 0
120 #define THREAD_GSCOPE_FLAG_USED 1
121 #define THREAD_GSCOPE_FLAG_WAIT 2
122 #define THREAD_GSCOPE_RESET_FLAG() \
123 do \
124 { int __res \
125 = atomic_exchange_release (&THREAD_SELF->header.gscope_flag, \
126 THREAD_GSCOPE_FLAG_UNUSED); \
127 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
128 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
129 } \
130 while (0)
131 #define THREAD_GSCOPE_SET_FLAG() \
132 do \
133 { \
134 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
135 atomic_write_barrier (); \
136 } \
137 while (0)
138
139 #endif /* __ASSEMBLER__ */
140
141 #endif /* tls.h */