1 /* Definition for thread-local data handling.  NPTL/ARM version.
2    Copyright (C) 2005,2007 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	1
22 
23 #ifndef __ASSEMBLER__
24 
25 # include <stdbool.h>
26 # include <stddef.h>
27 # include <stdint.h>
28 
29 /* Type for the dtv.  */
30 typedef union dtv
31 {
32   size_t counter;
33   struct
34   {
35     void *val;
36     bool is_static;
37   } pointer;
38 } dtv_t;
39 
40 #else /* __ASSEMBLER__ */
41 # include <tcb-offsets.h>
42 #endif /* __ASSEMBLER__ */
43 
44 
45 /* We require TLS support in the tools.  */
46 #define HAVE_TLS_SUPPORT                1
47 #define HAVE_TLS_MODEL_ATTRIBUTE        1
48 #define HAVE___THREAD                   1
49 
50 /* Signal that TLS support is available.  */
51 #define USE_TLS	1
52 
53 #ifndef __ASSEMBLER__
54 
55 /* Get system call information.  */
56 //# include <sysdep.h>
57 
58 /* The TP points to the start of the thread blocks.  */
59 # define TLS_DTV_AT_TP	1
60 
61 /* Get the thread descriptor definition.  */
62 # include <../../descr.h>
63 
64 typedef struct
65 {
66   dtv_t *dtv;
67   void *private_data;
68 } tcbhead_t;
69 
70 /* This is the size of the initial TCB.  */
71 # define TLS_INIT_TCB_SIZE	sizeof (tcbhead_t)
72 
73 /* Alignment requirements for the initial TCB.  */
74 # define TLS_INIT_TCB_ALIGN	16
75 
76 /* This is the size of the TCB.  */
77 # define TLS_TCB_SIZE		sizeof (tcbhead_t)
78 
79 /* This is the size we need before TCB.  */
80 # define TLS_PRE_TCB_SIZE	sizeof (struct pthread)
81 
82 /* Alignment requirements for the TCB.  */
83 # define TLS_TCB_ALIGN		16
84 
85 /* Install the dtv pointer.  The pointer passed is to the element with
86    index -1 which contain the length.  */
87 # define INSTALL_DTV(tcbp, dtvp) \
88   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
89 
90 /* Install new dtv for current thread.  */
91 # define INSTALL_NEW_DTV(dtv) \
92   (THREAD_DTV() = (dtv))
93 
94 /* Return dtv of given thread descriptor.  */
95 # define GET_DTV(tcbp) \
96   (((tcbhead_t *) (tcbp))->dtv)
97 
98 /* Code to initially initialize the thread pointer.  This might need
99    special attention since 'errno' is not yet available and if the
100    operation can cause a failure 'errno' must not be touched.  */
101 # define TLS_INIT_TP(tcbp, secondcall) \
102   ({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); NULL; })
103 
104 /* Return the address of the dtv for the current thread.  */
105 # define THREAD_DTV() \
106   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
107 
108 /* Return the thread descriptor for the current thread.  */
109 # define THREAD_SELF \
110  ((struct pthread *)__builtin_thread_pointer () - 1)
111 
112 /* Magic for libthread_db to know how to do THREAD_SELF.  */
113 # define DB_THREAD_SELF \
114   CONST_THREAD_AREA (32, sizeof (struct pthread))
115 
116 /* Access to data in the thread descriptor is easy.  */
117 #define THREAD_GETMEM(descr, member) \
118   descr->member
119 #define THREAD_GETMEM_NC(descr, member, idx) \
120   descr->member[idx]
121 #define THREAD_SETMEM(descr, member, value) \
122   descr->member = (value)
123 #define THREAD_SETMEM_NC(descr, member, idx, value) \
124   descr->member[idx] = (value)
125 
126 /* Initializing the thread pointer will generate a SIGILL if the syscall
127    is not available.  */
128 #define TLS_INIT_TP_EXPENSIVE 1
129 
130 /* Get and set the global scope generation counter in struct pthread.  */
131 #define THREAD_GSCOPE_FLAG_UNUSED 0
132 #define THREAD_GSCOPE_FLAG_USED   1
133 #define THREAD_GSCOPE_FLAG_WAIT   2
134 #define THREAD_GSCOPE_RESET_FLAG() \
135   do									     \
136     { int __res								     \
137 	= atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,	     \
138 			       THREAD_GSCOPE_FLAG_UNUSED);		     \
139       if (__res == THREAD_GSCOPE_FLAG_WAIT)				     \
140 	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
141     }									     \
142   while (0)
143 #define THREAD_GSCOPE_SET_FLAG() \
144   do									     \
145     {									     \
146       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;	     \
147       atomic_write_barrier ();						     \
148     }									     \
149   while (0)
150 #define THREAD_GSCOPE_WAIT() \
151   GL(dl_wait_lookup_done) ()
152 
153 #endif /* __ASSEMBLER__ */
154 
155 #endif	/* tls.h */
156