1 /* Definition for thread-local data handling.  NPTL/Alpha version.
2    Copyright (C) 2003, 2005 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    <http://www.gnu.org/licenses/>.  */
18 
19 #ifndef _TLS_H
20 #define _TLS_H	1
21 
22 #ifndef __ASSEMBLER__
23 # include <stdbool.h>
24 # include <stddef.h>
25 # include <stdint.h>
26 
27 /* Type for the dtv.  */
28 typedef union dtv
29 {
30   size_t counter;
31   struct
32   {
33     void *val;
34     bool is_static;
35   } pointer;
36 } dtv_t;
37 
38 #else /* __ASSEMBLER__ */
39 # include <tcb-offsets.h>
40 #endif /* __ASSEMBLER__ */
41 
42 
43 /* We require TLS support in the tools.  */
44 #ifndef HAVE_TLS_SUPPORT
45 # error "TLS support is required."
46 #endif
47 
48 /* Signal that TLS support is available.  */
49 # define USE_TLS	1
50 
51 #ifndef __ASSEMBLER__
52 
53 /* Get system call information.  */
54 # include <sysdep.h>
55 
56 /* The TP points to the start of the thread blocks.  */
57 # define TLS_DTV_AT_TP	1
58 
59 /* Get the thread descriptor definition.  */
60 # include <nptl/descr.h>
61 
62 typedef struct
63 {
64   dtv_t *dtv;
65   void *private;
66 } tcbhead_t;
67 
68 /* This is the size of the initial TCB.  */
69 # define TLS_INIT_TCB_SIZE	sizeof (tcbhead_t)
70 
71 /* Alignment requirements for the initial TCB.  */
72 # define TLS_INIT_TCB_ALIGN	16
73 
74 /* This is the size of the TCB.  */
75 # define TLS_TCB_SIZE		sizeof (tcbhead_t)
76 
77 /* This is the size we need before TCB.  */
78 # define TLS_PRE_TCB_SIZE	sizeof (struct pthread)
79 
80 /* Alignment requirements for the TCB.  */
81 # define TLS_TCB_ALIGN		16
82 
83 /* Install the dtv pointer.  The pointer passed is to the element with
84    index -1 which contain the length.  */
85 # define INSTALL_DTV(tcbp, dtvp) \
86   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
87 
88 /* Install new dtv for current thread.  */
89 # define INSTALL_NEW_DTV(dtv) \
90   (THREAD_DTV() = (dtv))
91 
92 /* Return dtv of given thread descriptor.  */
93 # define GET_DTV(tcbp) \
94   (((tcbhead_t *) (tcbp))->dtv)
95 
96 /* Code to initially initialize the thread pointer.  This might need
97    special attention since 'errno' is not yet available and if the
98    operation can cause a failure 'errno' must not be touched.  */
99 # define TLS_INIT_TP(tcbp, secondcall) \
100   (__builtin_set_thread_pointer ((void *)(tcbp)), NULL)
101 
102 /* Return the address of the dtv for the current thread.  */
103 # define THREAD_DTV() \
104   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
105 
106 /* Return the thread descriptor for the current thread.  */
107 # define THREAD_SELF \
108  ((struct pthread *)__builtin_thread_pointer () - 1)
109 
110 /* Magic for libthread_db to know how to do THREAD_SELF.  */
111 # define DB_THREAD_SELF \
112   REGISTER (64, 64, 32 * 8, -sizeof (struct pthread))
113 
114 /* Access to data in the thread descriptor is easy.  */
115 #define THREAD_GETMEM(descr, member) \
116   descr->member
117 #define THREAD_GETMEM_NC(descr, member, idx) \
118   descr->member[idx]
119 #define THREAD_SETMEM(descr, member, value) \
120   descr->member = (value)
121 #define THREAD_SETMEM_NC(descr, member, idx, value) \
122   descr->member[idx] = (value)
123 
124 #endif /* __ASSEMBLER__ */
125 
126 #endif	/* tls.h */
127