1 /* Definition for thread-local data handling. NPTL/hppa 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 #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. */
50 # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
51
52 /* This is the size of the TCB. */
53 # define TLS_TCB_SIZE sizeof (tcbhead_t)
54
55 /* This is the size we need before TCB */
56 # define TLS_PRE_TCB_SIZE sizeof (struct pthread)
57
58 /* Install the dtv pointer. The pointer passed is to the element with
59 index -1 which contain the length. */
60 # define INSTALL_DTV(tcbp, dtvp) \
61 ((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1
62
63 /* Install new dtv for current thread. */
64 # define INSTALL_NEW_DTV(dtv) \
65 ({ tcbhead_t *__tcbp = (tcbhead_t *)__get_cr27(); \
66 __tcbp->dtv = dtv; \
67 })
68
69 /* Return dtv of given thread descriptor. */
70 # define GET_DTV(tcbp) \
71 (((tcbhead_t *) (tcbp))->dtv)
72
73 /* Code to initially initialize the thread pointer. This might need
74 special attention since 'errno' is not yet available and if the
75 operation can cause a failure 'errno' must not be touched. */
76 # define TLS_INIT_TP(tcbp) \
77 ({ __set_cr27(tcbp); true; })
78
79 /* Value passed to 'clone' for initialization of the thread register. */
80 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
81
82 /* Return the address of the dtv for the current thread. */
83 # define THREAD_DTV() \
84 ({ tcbhead_t *__tcbp = (tcbhead_t *)__get_cr27(); \
85 __tcbp->dtv; \
86 })
87
88 /* Return the thread descriptor for the current thread. */
89 # define THREAD_SELF \
90 ({ struct pthread *__self; \
91 __self = __get_cr27(); \
92 __self - 1; \
93 })
94
95 /* Magic for libthread_db to know how to do THREAD_SELF.
96 Our thread pointer is stored in cr27. See asm/elf.h for the offset into
97 elf_gregset_t. The thread descriptor is sizeof (struct pthread) away. */
98 # define DB_THREAD_SELF \
99 REGISTER (32, 32, 53 * 4, -sizeof (struct pthread))
100
101 # include <tcb-access.h>
102
103 static inline struct pthread *__get_cr27(void)
104 {
105 long cr27;
106 asm ("mfctl %%cr27, %0" : "=r" (cr27) : );
107 return (struct pthread *) cr27;
108 }
109
110 /* We write to cr27, clobber r26 as the input argument, and clobber
111 r31 as the link register. */
112 static inline void __set_cr27(struct pthread *cr27)
113 {
114 asm ( "ble 0xe0(%%sr2, %%r0)\n\t"
115 "copy %0, %%r26"
116 : : "r" (cr27) : "r26", "r31" );
117 }
118
119 /* Get and set the global scope generation counter in struct pthread. */
120 #define THREAD_GSCOPE_FLAG_UNUSED 0
121 #define THREAD_GSCOPE_FLAG_USED 1
122 #define THREAD_GSCOPE_FLAG_WAIT 2
123 #define THREAD_GSCOPE_RESET_FLAG() \
124 do \
125 { int __res \
126 = atomic_exchange_release (&THREAD_SELF->header.gscope_flag, \
127 THREAD_GSCOPE_FLAG_UNUSED); \
128 if (__res == THREAD_GSCOPE_FLAG_WAIT) \
129 lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
130 } \
131 while (0)
132 #define THREAD_GSCOPE_SET_FLAG() \
133 do \
134 { \
135 THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
136 atomic_write_barrier (); \
137 } \
138 while (0)
139
140 #endif /* !__ASSEMBLER__ */
141
142 #endif /* tls.h */