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, write to the Free
17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18    02111-1307 USA.  */
19 
20 #ifndef _TLS_H
21 #define _TLS_H	1
22 
23 #ifndef __ASSEMBLER__
24 # include <stdbool.h>
25 # include <stddef.h>
26 # include <stdint.h>
27 
28 /* Type for the dtv.  */
29 typedef union dtv
30 {
31   size_t counter;
32   struct
33   {
34     void *val;
35     bool is_static;
36   } pointer;
37 } dtv_t;
38 
39 #else /* __ASSEMBLER__ */
40 # include <tcb-offsets.h>
41 #endif /* __ASSEMBLER__ */
42 
43 
44 /* We require TLS support in the tools.  */
45 #ifndef HAVE_TLS_SUPPORT
46 # error "TLS support is required."
47 #endif
48 
49 /* Signal that TLS support is available.  */
50 # define USE_TLS	1
51 
52 #ifndef __ASSEMBLER__
53 
54 /* Get system call information.  */
55 # include <sysdep.h>
56 
57 /* The TP points to the start of the thread blocks.  */
58 # define TLS_DTV_AT_TP	1
59 
60 /* Get the thread descriptor definition.  */
61 # include <nptl/descr.h>
62 
63 typedef struct
64 {
65   dtv_t *dtv;
66   void *private;
67 } tcbhead_t;
68 
69 /* This is the size of the initial TCB.  */
70 # define TLS_INIT_TCB_SIZE	sizeof (tcbhead_t)
71 
72 /* Alignment requirements for the initial TCB.  */
73 # define TLS_INIT_TCB_ALIGN	16
74 
75 /* This is the size of the TCB.  */
76 # define TLS_TCB_SIZE		sizeof (tcbhead_t)
77 
78 /* This is the size we need before TCB.  */
79 # define TLS_PRE_TCB_SIZE	sizeof (struct pthread)
80 
81 /* Alignment requirements for the TCB.  */
82 # define TLS_TCB_ALIGN		16
83 
84 /* Install the dtv pointer.  The pointer passed is to the element with
85    index -1 which contain the length.  */
86 # define INSTALL_DTV(tcbp, dtvp) \
87   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
88 
89 /* Install new dtv for current thread.  */
90 # define INSTALL_NEW_DTV(dtv) \
91   (THREAD_DTV() = (dtv))
92 
93 /* Return dtv of given thread descriptor.  */
94 # define GET_DTV(tcbp) \
95   (((tcbhead_t *) (tcbp))->dtv)
96 
97 /* Code to initially initialize the thread pointer.  This might need
98    special attention since 'errno' is not yet available and if the
99    operation can cause a failure 'errno' must not be touched.  */
100 # define TLS_INIT_TP(tcbp, secondcall) \
101   (__builtin_set_thread_pointer ((void *)(tcbp)), NULL)
102 
103 /* Return the address of the dtv for the current thread.  */
104 # define THREAD_DTV() \
105   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
106 
107 /* Return the thread descriptor for the current thread.  */
108 # define THREAD_SELF \
109  ((struct pthread *)__builtin_thread_pointer () - 1)
110 
111 /* Magic for libthread_db to know how to do THREAD_SELF.  */
112 # define DB_THREAD_SELF \
113   REGISTER (64, 64, 32 * 8, -sizeof (struct pthread))
114 
115 /* Access to data in the thread descriptor is easy.  */
116 #define THREAD_GETMEM(descr, member) \
117   descr->member
118 #define THREAD_GETMEM_NC(descr, member, idx) \
119   descr->member[idx]
120 #define THREAD_SETMEM(descr, member, value) \
121   descr->member = (value)
122 #define THREAD_SETMEM_NC(descr, member, idx, value) \
123   descr->member[idx] = (value)
124 
125 #endif /* __ASSEMBLER__ */
126 
127 #endif	/* tls.h */
128