1 /* Definition for thread-local data handling.  NPTL/m68k version.
2    Copyright (C) 2010-2017 Free Software Foundation, Inc.
3    Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
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, see
17    <http://www.gnu.org/licenses/>.  */
18 
19 #ifndef _TLS_H
20 #define _TLS_H	1
21 
22 #ifndef __ASSEMBLER__
23 # include <stdbool.h>
24 # include <stddef.h>
25 # include <stdint.h>
26 
27 /* Type for the dtv.  */
28 typedef union dtv
29 {
30   size_t counter;
31   struct
32   {
33     void *val;
34     bool is_static;
35   } pointer;
36 } dtv_t;
37 
38 /* Value used for dtv entries for which the allocation is delayed.  */
39 #define TLS_DTV_UNALLOCATED ((void *) -1l)
40 
41 #else /* __ASSEMBLER__ */
42 # include <tcb-offsets.h>
43 #endif /* __ASSEMBLER__ */
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;
68 } tcbhead_t;
69 
70 /* This is the size of the initial TCB.  Because our TCB is before the thread
71    pointer, we don't need this.  */
72 # define TLS_INIT_TCB_SIZE	0
73 
74 /* Alignment requirements for the initial TCB.  */
75 # define TLS_INIT_TCB_ALIGN	__alignof__ (struct pthread)
76 
77 /* This is the size of the TCB.  Because our TCB is before the thread
78    pointer, we don't need this.  */
79 # define TLS_TCB_SIZE		0
80 
81 /* Alignment requirements for the TCB.  */
82 # define TLS_TCB_ALIGN		__alignof__ (struct pthread)
83 
84 /* This is the size we need before TCB - actually, it includes the TCB.  */
85 # define TLS_PRE_TCB_SIZE						\
86   (sizeof (struct pthread)						\
87    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
88 
89 /* The thread pointer (TP) points to the end of the
90    TCB + 0x7000, as for PowerPC and MIPS.  This implies that TCB address is
91    TP - 0x7000.  As we define TLS_DTV_AT_TP we can
92    assume that the pthread struct is allocated immediately ahead of the
93    TCB.  This implies that the pthread_descr address is
94    TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
95 # define TLS_TCB_OFFSET	0x7000
96 
97 /* Install the dtv pointer.  The pointer passed is to the element with
98    index -1 which contain the length.  */
99 # define INSTALL_DTV(tcbp, dtvp) \
100   ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
101 
102 /* Install new dtv for current thread.  */
103 # define INSTALL_NEW_DTV(dtv) \
104   (THREAD_DTV () = (dtv))
105 
106 /* Return dtv of given thread descriptor.  */
107 # define GET_DTV(tcbp) \
108   (((tcbhead_t *) (tcbp))[-1].dtv)
109 
110 /* Code to initially initialize the thread pointer.  This might need
111    special attention since 'errno' is not yet available and if the
112    operation can cause a failure 'errno' must not be touched.  */
113 # define TLS_INIT_TP(tcbp, secondcall)					\
114   ({									\
115     INTERNAL_SYSCALL_DECL (err);					\
116     int result_var;							\
117     result_var = INTERNAL_SYSCALL (set_thread_area, err, 1,		\
118 			    ((void *) (tcbp)) + TLS_TCB_OFFSET); 	\
119     INTERNAL_SYSCALL_ERROR_P (result_var, err) 				\
120       ? "unknown error" : NULL; })
121 
122 # define TLS_DEFINE_INIT_TP(tp, pd) \
123   void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
124 
125 extern void * __m68k_read_tp (void);
126 
127 /* Return the address of the dtv for the current thread.  */
128 # define THREAD_DTV() \
129   (((tcbhead_t *) (__m68k_read_tp () - TLS_TCB_OFFSET))[-1].dtv)
130 
131 /* Return the thread descriptor for the current thread.  */
132 # define THREAD_SELF \
133   ((struct pthread *) (__m68k_read_tp () - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
134 
135 /* Magic for libthread_db to know how to do THREAD_SELF.  */
136 # define DB_THREAD_SELF \
137   CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
138 
139 /* Access to data in the thread descriptor is easy.  */
140 # define THREAD_GETMEM(descr, member) \
141   descr->member
142 # define THREAD_GETMEM_NC(descr, member, idx) \
143   descr->member[idx]
144 # define THREAD_SETMEM(descr, member, value) \
145   descr->member = (value)
146 # define THREAD_SETMEM_NC(descr, member, idx, value) \
147   descr->member[idx] = (value)
148 
149 /* l_tls_offset == 0 is perfectly valid on M68K, so we have to use some
150    different value to mean unset l_tls_offset.  */
151 # define NO_TLS_OFFSET		-1
152 
153 /* Get and set the global scope generation counter in struct pthread.  */
154 #define THREAD_GSCOPE_FLAG_UNUSED 0
155 #define THREAD_GSCOPE_FLAG_USED   1
156 #define THREAD_GSCOPE_FLAG_WAIT   2
157 #define THREAD_GSCOPE_RESET_FLAG()					\
158   do									\
159     { int __res								\
160 	= atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,	\
161 			       THREAD_GSCOPE_FLAG_UNUSED);		\
162       if (__res == THREAD_GSCOPE_FLAG_WAIT)				\
163 	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
164     }									\
165   while (0)
166 #define THREAD_GSCOPE_SET_FLAG()					\
167   do									\
168     {									\
169       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;	\
170       atomic_write_barrier ();						\
171     }									\
172   while (0)
173 #define THREAD_GSCOPE_WAIT() \
174   GL(dl_wait_lookup_done) ()
175 
176 #endif /* __ASSEMBLER__ */
177 
178 #endif	/* tls.h */
179