1 /* Definition for thread-local data handling.  NPTL/SH version.
2    Copyright (C) 2003, 2005, 2006, 2007 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
22 
23 #ifndef __ASSEMBLER__
24 # include <stdbool.h>
25 # include <stddef.h>
26 # include <stdint.h>
27 # include <stdlib.h>
28 # include <list.h>
29 # include <sysdep.h>
30 # include <bits/kernel-features.h>
31 
32 /* Type for the dtv.  */
33 typedef union dtv
34 {
35   size_t counter;
36   struct
37   {
38     void *val;
39     bool is_static;
40   } pointer;
41 } dtv_t;
42 
43 typedef struct
44 {
45   dtv_t *dtv;
46   uintptr_t pointer_guard;
47 } tcbhead_t;
48 
49 # define TLS_MULTIPLE_THREADS_IN_TCB 1
50 
51 #else /* __ASSEMBLER__ */
52 # include <tcb-offsets.h>
53 #endif /* __ASSEMBLER__ */
54 
55 
56 /* We require TLS support in the tools.  */
57 #define HAVE_TLS_SUPPORT
58 #define HAVE___THREAD   1
59 #define HAVE_TLS_MODEL_ATTRIBUTE       1
60 /* Signal that TLS support is available.  */
61 # define USE_TLS       1
62 
63 #ifndef __ASSEMBLER__
64 
65 /* Get system call information.  */
66 # include <sysdep.h>
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 __alignof__ (tcbhead_t)
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 __alignof__ (struct pthread)
82 
83 /* The TLS blocks start right after the TCB.  */
84 # define TLS_DTV_AT_TP	1
85 
86 /* Get the thread descriptor definition.  */
87 # include <descr.h>
88 
89 /* Install the dtv pointer.  The pointer passed is to the element with
90    index -1 which contain the length.  */
91 # define INSTALL_DTV(tcbp, dtvp) \
92   ((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1
93 
94 /* Install new dtv for current thread.  */
95 # define INSTALL_NEW_DTV(dtv) \
96   ({ tcbhead_t *__tcbp;							      \
97      __asm__ __volatile__ ("stc gbr,%0" : "=r" (__tcbp));			      \
98      __tcbp->dtv = (dtv);})
99 
100 /* Return dtv of given thread descriptor.  */
101 # define GET_DTV(tcbp) \
102   (((tcbhead_t *) (tcbp))->dtv)
103 
104 /* Code to initially initialize the thread pointer.  This might need
105    special attention since 'errno' is not yet available and if the
106    operation can cause a failure 'errno' must not be touched.  */
107 # define TLS_INIT_TP(tcbp, secondcall) \
108   ({ __asm__ __volatile__ ("ldc %0,gbr" : : "r" (tcbp)); 0; })
109 
110 /* Return the address of the dtv for the current thread.  */
111 # define THREAD_DTV() \
112   ({ tcbhead_t *__tcbp;							      \
113      __asm__ __volatile__ ("stc gbr,%0" : "=r" (__tcbp));			      \
114      __tcbp->dtv;})
115 
116 /* Return the thread descriptor for the current thread.
117    The contained asm must *not* be marked volatile since otherwise
118    assignments like
119         struct pthread *self = thread_self();
120    do not get optimized away.  */
121 # define THREAD_SELF \
122   ({ struct pthread *__self;						      \
123      __asm__ ("stc gbr,%0" : "=r" (__self));				      \
124      __self - 1;})
125 
126 /* Magic for libthread_db to know how to do THREAD_SELF.  */
127 # define DB_THREAD_SELF \
128   REGISTER (32, 32, REG_GBR * 4, -sizeof (struct pthread))
129 
130 /* Read member of the thread descriptor directly.  */
131 # define THREAD_GETMEM(descr, member) (descr->member)
132 
133 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
134 # define THREAD_GETMEM_NC(descr, member, idx) (descr->member[idx])
135 
136 /* Set member of the thread descriptor directly.  */
137 # define THREAD_SETMEM(descr, member, value) \
138     descr->member = (value)
139 
140 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
141 # define THREAD_SETMEM_NC(descr, member, idx, value) \
142     descr->member[idx] = (value)
143 
144 #define THREAD_GET_POINTER_GUARD() \
145   ({ tcbhead_t *__tcbp;							      \
146      __asm__ __volatile__ ("stc gbr,%0" : "=r" (__tcbp));			      \
147      __tcbp->pointer_guard;})
148  #define THREAD_SET_POINTER_GUARD(value) \
149   ({ tcbhead_t *__tcbp;							      \
150      __asm__ __volatile__ ("stc gbr,%0" : "=r" (__tcbp));			      \
151      __tcbp->pointer_guard = (value);})
152 #define THREAD_COPY_POINTER_GUARD(descr) \
153   ({ tcbhead_t *__tcbp;							      \
154      __asm__ __volatile__ ("stc gbr,%0" : "=r" (__tcbp));			      \
155      ((tcbhead_t *) (descr + 1))->pointer_guard	= __tcbp->pointer_guard;})
156 
157 /* Get and set the global scope generation counter in struct pthread.  */
158 #define THREAD_GSCOPE_FLAG_UNUSED 0
159 #define THREAD_GSCOPE_FLAG_USED   1
160 #define THREAD_GSCOPE_FLAG_WAIT   2
161 #define THREAD_GSCOPE_RESET_FLAG() \
162   do									     \
163     { int __res								     \
164 	= atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,	     \
165 			       THREAD_GSCOPE_FLAG_UNUSED);		     \
166       if (__res == THREAD_GSCOPE_FLAG_WAIT)				     \
167 	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
168     }									     \
169   while (0)
170 #define THREAD_GSCOPE_SET_FLAG() \
171   do									     \
172     {									     \
173       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;	     \
174       atomic_write_barrier ();						     \
175     }									     \
176   while (0)
177 #define THREAD_GSCOPE_WAIT() \
178   GL(dl_wait_lookup_done) ()
179 
180 #endif /* __ASSEMBLER__ */
181 
182 #endif	/* tls.h */
183