summaryrefslogtreecommitdiff
path: root/libpthread/linuxthreads/sysdeps/powerpc/tls.h
blob: 1ae0b60ff12d1dc2f6203a40746b6fa332ceccfd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
/* Definitions for thread-local data handling.  linuxthreads/PPC version.
   Copyright (C) 2003, 2005 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _TLS_H
#define _TLS_H

#ifndef __ASSEMBLER__

# include <pt-machine.h>
# include <stdbool.h>
# include <stddef.h>

/* Type for the dtv.  */
typedef union dtv
{
  size_t counter;
  struct
  {
    void *val;
    bool is_static;
  } pointer;
} dtv_t;

#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif /* __ASSEMBLER__ */

#ifdef HAVE_TLS_SUPPORT

/* Signal that TLS support is available.  */
# define USE_TLS	1

# ifndef __ASSEMBLER__

/* This layout is actually wholly private and not affected by the ABI.
   Nor does it overlap the pthread data structure, so we need nothing
   extra here at all.  */
typedef struct
{
  dtv_t *dtv;
} tcbhead_t;

/* This is the size of the initial TCB.  */
#  define TLS_INIT_TCB_SIZE	0

/* Alignment requirements for the initial TCB.  */
#  define TLS_INIT_TCB_ALIGN	__alignof__ (struct _pthread_descr_struct)

/* This is the size of the TCB.  */
#  define TLS_TCB_SIZE		0

/* Alignment requirements for the TCB.  */
#  define TLS_TCB_ALIGN		__alignof__ (struct _pthread_descr_struct)

/* This is the size we need before TCB.  */
#  define TLS_PRE_TCB_SIZE \
  (sizeof (struct _pthread_descr_struct)				      \
   + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))

/* The following assumes that TP (R2 or R13) is points to the end of the
   TCB + 0x7000 (per the ABI).  This implies that TCB address is
   TP - 0x7000.  As we define TLS_DTV_AT_TP we can
   assume that the pthread_descr is allocated immediately ahead of the
   TCB.  This implies that the pthread_descr address is
   TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
#define TLS_TCB_OFFSET		0x7000

/* The DTV is allocated at the TP; the TCB is placed elsewhere.  */
/* This is not really true for powerpc64.  We are following alpha
   where the DTV pointer is first doubleword in the TCB.  */
#  define TLS_DTV_AT_TP 1

/* Install the dtv pointer.  The pointer passed is to the element with
   index -1 which contain the length.  */
#  define INSTALL_DTV(TCBP, DTVP) \
  (((tcbhead_t *) (TCBP))[-1].dtv = (DTVP) + 1)

/* Install new dtv for current thread.  */
#  define INSTALL_NEW_DTV(DTV) (THREAD_DTV() = (DTV))

/* Return dtv of given thread descriptor.  */
#  define GET_DTV(TCBP)	(((tcbhead_t *) (TCBP))[-1].dtv)

/* We still need this define so that tcb-offsets.sym can override it and
   use THREAD_SELF to generate MULTIPLE_THREADS_OFFSET.  */
#  define __thread_register ((void *) __thread_self)

/* Code to initially initialize the thread pointer.  This might need
   special attention since 'errno' is not yet available and if the
   operation can cause a failure 'errno' must not be touched.

   The global register variable is declared in pt-machine.h with the
   wrong type, so we need some extra casts to get the desired result.
   This avoids a lvalue cast that gcc-3.4 does not like.  */
# define TLS_INIT_TP(TCBP, SECONDCALL) \
    (__thread_self = (struct _pthread_descr_struct *) \
	((void *) (TCBP) + TLS_TCB_OFFSET), NULL)

/* Return the address of the dtv for the current thread.  */
#  define THREAD_DTV() \
     (((tcbhead_t *) ((void *) __thread_self - TLS_TCB_OFFSET))[-1].dtv)

/* Return the thread descriptor for the current thread.  */
#  undef THREAD_SELF
#  define THREAD_SELF \
    ((pthread_descr) (__thread_register \
		      - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))

#  undef INIT_THREAD_SELF
#  define INIT_THREAD_SELF(DESCR, NR) \
     (__thread_self = (struct _pthread_descr_struct *)((void *) (DESCR) \
		           + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE))

/* Make sure we have the p_multiple_threads member in the thread structure.
   See below.  */
#  define TLS_MULTIPLE_THREADS_IN_TCB 1

/* Get the thread descriptor definition.  */
#  include <linuxthreads/descr.h>

/* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
   different value to mean unset l_tls_offset.  */
#  define NO_TLS_OFFSET	-1

# endif /* __ASSEMBLER__ */

#elif !defined __ASSEMBLER__

/* This overlaps the start of the pthread_descr.  System calls
   and such use this to find the multiple_threads flag and need
   to use the same offset relative to the thread register in both
   single-threaded and multi-threaded code.  */
typedef struct
{
  void *tcb;			/* Never used.  */
  dtv_t *dtv;			/* Never used.  */
  void *self;			/* Used only if multithreaded, and rarely.  */
  int multiple_threads;		/* Only this member is really used.  */
} tcbhead_t;

#define NONTLS_INIT_TP							\
  do {									\
    static const tcbhead_t nontls_init_tp = { .multiple_threads = 0 };	\
    __thread_self = (__typeof (__thread_self)) &nontls_init_tp;		\
  } while (0)

#endif /* HAVE_TLS_SUPPORT */

#endif	/* tls.h */