1 /* Definition for thread-local data handling.  NPTL/Xtensa version.
2    Copyright (C) 2012 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; see the file COPYING.LIB.  If
17    not, see <http://www.gnu.org/licenses/>.  */
18 
19 #ifndef _TLS_H
20 #define _TLS_H
21 
22 #ifndef __ASSEMBLER__
23 
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 
40 #else /* __ASSEMBLER__ */
41 # include <tcb-offsets.h>
42 #endif /* __ASSEMBLER__ */
43 
44 /* We require TLS support in the tools.  */
45 #define HAVE_TLS_SUPPORT                1
46 #define HAVE_TLS_MODEL_ATTRIBUTE        1
47 #define HAVE___THREAD                   1
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 TLS blocks start right after the TCB.  */
58 # define TLS_DTV_AT_TP	1
59 
60 /* Get the thread descriptor definition.  */
61 # include <../../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 
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   ({ tcbhead_t *__tcbp;							\
93      __asm__ __volatile__ ("rur %0, threadptr" : "=r" (__tcbp));	\
94      __tcbp->dtv = (dtv); })						\
95 
96 /* Return dtv of given thread descriptor.  */
97 # define GET_DTV(tcbp) \
98   (((tcbhead_t *) (tcbp))->dtv)
99 
100 /* Code to initially initialize the thread pointer.  This might need
101    special attention since 'errno' is not yet available and if the
102    operation can cause a failure 'errno' must not be touched.  */
103 # define TLS_INIT_TP(tcbp, secondcall)					\
104   ({ __asm__ __volatile__ ("wur %0, threadptr" : : "r" (tcbp)); 0; })
105 
106 /* Return the address of the dtv for the current thread.  */
107 # define THREAD_DTV()							\
108   ({ tcbhead_t *__tcbp;							\
109       __asm__ __volatile__ ("rur %0, threadptr" : "=r" (__tcbp));	\
110       __tcbp->dtv; })
111 
112 /* Return the thread descriptor for the current thread.  */
113 # define THREAD_SELF							\
114  ({ struct pthread *__self;						\
115     __asm__ ("rur %0, threadptr" : "=r" (__self));			\
116     __self - 1; })
117 
118 /* Magic for libthread_db to know how to do THREAD_SELF.  */
119 # define DB_THREAD_SELF \
120   CONST_THREAD_AREA (32, sizeof (struct pthread))
121 
122 /* Access to data in the thread descriptor is easy.  */
123 #define THREAD_GETMEM(descr, member) \
124   descr->member
125 #define THREAD_GETMEM_NC(descr, member, idx) \
126   descr->member[idx]
127 #define THREAD_SETMEM(descr, member, value) \
128   descr->member = (value)
129 #define THREAD_SETMEM_NC(descr, member, idx, value) \
130   descr->member[idx] = (value)
131 
132 /* Get and set the global scope generation counter in struct pthread.  */
133 #define THREAD_GSCOPE_FLAG_UNUSED 0
134 #define THREAD_GSCOPE_FLAG_USED   1
135 #define THREAD_GSCOPE_FLAG_WAIT   2
136 #define THREAD_GSCOPE_RESET_FLAG() \
137   do									     \
138     { int __res								     \
139 	= atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,	     \
140 			       THREAD_GSCOPE_FLAG_UNUSED);		     \
141       if (__res == THREAD_GSCOPE_FLAG_WAIT)				     \
142 	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
143     }									     \
144   while (0)
145 #define THREAD_GSCOPE_SET_FLAG() \
146   do									     \
147     {									     \
148       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;	     \
149       atomic_write_barrier ();						     \
150     }									     \
151   while (0)
152 
153 #define THREAD_GSCOPE_WAIT() \
154   GL(dl_wait_lookup_done) ()
155 
156 #endif /* __ASSEMBLER__ */
157 
158 #endif	/* tls.h */
159