sysdeps/powerpc/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/PowerPC version.
   2    Copyright (C) 2003-2018 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _TLS_H
  20 #define _TLS_H  1
  21
  22 # include <dl-sysdep.h>
  23
  24 #ifndef __ASSEMBLER__
  25 # include <stdbool.h>
  26 # include <stddef.h>
  27 # include <stdint.h>
  28 # include <dl-dtv.h>
  29
  30 #else /* __ASSEMBLER__ */
  31 # include <tcb-offsets.h>
  32 #endif /* __ASSEMBLER__ */
  33
  34
  35 #ifndef __ASSEMBLER__
  36
  37 # include <hwcapinfo.h>
  38
  39 /* Get system call information.  */
  40 # include <sysdep.h>
  41
  42 /* The TP points to the start of the thread blocks.  */
  43 # define TLS_DTV_AT_TP  1
  44 # define TLS_TCB_AT_TP  0
  45
  46 /* We use the multiple_threads field in the pthread struct */
  47 #define TLS_MULTIPLE_THREADS_IN_TCB     1
  48
  49 /* Get the thread descriptor definition.  */
  50 # include <nptl/descr.h>
  51
  52
  53 /* The stack_guard is accessed directly by GCC -fstack-protector code,
  54    so it is a part of public ABI.  The dtv and pointer_guard fields
  55    are private.  */
  56 typedef struct
  57 {
  58   /* Reservation for HWCAP data.  To be accessed by GCC in
  59      __builtin_cpu_supports(), so it is a part of public ABI.  */
  60   uint64_t hwcap;
  61   /* Reservation for AT_PLATFORM data.  To be accessed by GCC in
  62      __builtin_cpu_is(), so it is a part of public ABI.  Since there
  63      are different ABIs for 32 and 64 bit, we put this field in a
  64      previously empty padding space for powerpc64.  */
  65 #ifndef __powerpc64__
  66   /* Padding to maintain alignment.  */
  67   uint32_t padding;
  68   uint32_t at_platform;
  69 #endif
  70   uint32_t __unused;
  71   /* Reservation for AT_PLATFORM data - powerpc64.  */
  72 #ifdef __powerpc64__
  73   uint32_t at_platform;
  74 #endif
  75   /* Reservation for Dynamic System Optimizer ABI.  */
  76   uintptr_t dso_slot2;
  77   uintptr_t dso_slot1;
  78   /* Reservation for tar register (ISA 2.07).  */
  79   uintptr_t tar_save;
  80   /* GCC split stack support.  */
  81   void *__private_ss;
  82   /* Reservation for the Event-Based Branching ABI.  */
  83   uintptr_t ebb_handler;
  84   uintptr_t ebb_ctx_pointer;
  85   uintptr_t ebb_reserved1;
  86   uintptr_t ebb_reserved2;
  87   uintptr_t pointer_guard;
  88   uintptr_t stack_guard;
  89   dtv_t *dtv;
  90 } tcbhead_t;
  91
  92 /* This is the size of the initial TCB.  */
  93 # define TLS_INIT_TCB_SIZE      0
  94
  95 /* Alignment requirements for the initial TCB.  */
  96 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  97
  98 /* This is the size of the TCB.  */
  99 # define TLS_TCB_SIZE           0
 100
 101 /* Alignment requirements for the TCB.  */
 102 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
 103
 104 /* This is the size we need before TCB.  */
 105 # define TLS_PRE_TCB_SIZE \
 106   (sizeof (struct pthread)                                                    \
 107    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
 108
 109 # ifndef __powerpc64__
 110 /* Register r2 (tp) is reserved by the ABI as "thread pointer". */
 111 register void *__thread_register __asm__ ("r2");
 112 #  define PT_THREAD_POINTER PT_R2
 113 # else
 114 /* Register r13 (tp) is reserved by the ABI as "thread pointer". */
 115 register void *__thread_register __asm__ ("r13");
 116 #  define PT_THREAD_POINTER PT_R13
 117 # endif
 118
 119 /* The following assumes that TP (R2 or R13) points to the end of the
 120    TCB + 0x7000 (per the ABI).  This implies that TCB address is
 121    TP - 0x7000.  As we define TLS_DTV_AT_TP we can
 122    assume that the pthread struct is allocated immediately ahead of the
 123    TCB.  This implies that the pthread_descr address is
 124    TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
 125 # define TLS_TCB_OFFSET 0x7000
 126
 127 /* Install the dtv pointer.  The pointer passed is to the element with
 128    index -1 which contain the length.  */
 129 # define INSTALL_DTV(tcbp, dtvp) \
 130   ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
 131
 132 /* Install new dtv for current thread.  */
 133 # define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
 134
 135 /* Return dtv of given thread descriptor.  */
 136 # define GET_DTV(tcbp)  (((tcbhead_t *) (tcbp))[-1].dtv)
 137
 138 /* Code to initially initialize the thread pointer.  This might need
 139    special attention since 'errno' is not yet available and if the
 140    operation can cause a failure 'errno' must not be touched.  */
 141 # define TLS_INIT_TP(tcbp) \
 142   ({                                                                          \
 143     __thread_register = (void *) (tcbp) + TLS_TCB_OFFSET;                     \
 144     THREAD_SET_HWCAP (__tcb_hwcap);                                           \
 145     THREAD_SET_AT_PLATFORM (__tcb_platform);                                  \
 146     NULL;                                                                     \
 147   })
 148
 149 /* Value passed to 'clone' for initialization of the thread register.  */
 150 # define TLS_DEFINE_INIT_TP(tp, pd) \
 151     void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE;             \
 152     (((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].hwcap) =              \
 153       THREAD_GET_HWCAP ();                                                    \
 154     (((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].at_platform) =        \
 155       THREAD_GET_AT_PLATFORM ();
 156
 157 /* Return the address of the dtv for the current thread.  */
 158 # define THREAD_DTV() \
 159     (((tcbhead_t *) (__thread_register - TLS_TCB_OFFSET))[-1].dtv)
 160
 161 /* Return the thread descriptor for the current thread.  */
 162 # define THREAD_SELF \
 163     ((struct pthread *) (__thread_register \
 164                          - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 165
 166 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 167 # define DB_THREAD_SELF                                                       \
 168   REGISTER (32, 32, PT_THREAD_POINTER * 4,                                    \
 169             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)                              \
 170   REGISTER (64, 64, PT_THREAD_POINTER * 8,                                    \
 171             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
 172
 173 /* Read member of the thread descriptor directly.  */
 174 # define THREAD_GETMEM(descr, member) ((void)(descr), (THREAD_SELF)->member)
 175
 176 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 177 # define THREAD_GETMEM_NC(descr, member, idx) \
 178     ((void)(descr), (THREAD_SELF)->member[idx])
 179
 180 /* Set member of the thread descriptor directly.  */
 181 # define THREAD_SETMEM(descr, member, value) \
 182     ((void)(descr), (THREAD_SELF)->member = (value))
 183
 184 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 185 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 186     ((void)(descr), (THREAD_SELF)->member[idx] = (value))
 187
 188 /* Set the stack guard field in TCB head.  */
 189 # define THREAD_SET_STACK_GUARD(value) \
 190     (((tcbhead_t *) ((char *) __thread_register                               \
 191                      - TLS_TCB_OFFSET))[-1].stack_guard = (value))
 192 # define THREAD_COPY_STACK_GUARD(descr) \
 193     (((tcbhead_t *) ((char *) (descr)                                         \
 194                      + TLS_PRE_TCB_SIZE))[-1].stack_guard                     \
 195      = ((tcbhead_t *) ((char *) __thread_register                             \
 196                        - TLS_TCB_OFFSET))[-1].stack_guard)
 197
 198 /* Set the stack guard field in TCB head.  */
 199 # define THREAD_GET_POINTER_GUARD() \
 200     (((tcbhead_t *) ((char *) __thread_register                               \
 201                      - TLS_TCB_OFFSET))[-1].pointer_guard)
 202 # define THREAD_SET_POINTER_GUARD(value) \
 203     (THREAD_GET_POINTER_GUARD () = (value))
 204 # define THREAD_COPY_POINTER_GUARD(descr) \
 205     (((tcbhead_t *) ((char *) (descr)                                         \
 206                      + TLS_PRE_TCB_SIZE))[-1].pointer_guard                   \
 207      = THREAD_GET_POINTER_GUARD())
 208
 209 /* hwcap field in TCB head.  */
 210 # define THREAD_GET_HWCAP() \
 211     (((tcbhead_t *) ((char *) __thread_register                               \
 212                      - TLS_TCB_OFFSET))[-1].hwcap)
 213 # define THREAD_SET_HWCAP(value) \
 214     (THREAD_GET_HWCAP () = (value))
 215
 216 /* at_platform field in TCB head.  */
 217 # define THREAD_GET_AT_PLATFORM() \
 218     (((tcbhead_t *) ((char *) __thread_register                               \
 219                      - TLS_TCB_OFFSET))[-1].at_platform)
 220 # define THREAD_SET_AT_PLATFORM(value) \
 221     (THREAD_GET_AT_PLATFORM () = (value))
 222
 223 /* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
 224    different value to mean unset l_tls_offset.  */
 225 # define NO_TLS_OFFSET          -1
 226
 227 /* Get and set the global scope generation counter in struct pthread.  */
 228 #define THREAD_GSCOPE_IN_TCB      1
 229 #define THREAD_GSCOPE_FLAG_UNUSED 0
 230 #define THREAD_GSCOPE_FLAG_USED   1
 231 #define THREAD_GSCOPE_FLAG_WAIT   2
 232 #define THREAD_GSCOPE_RESET_FLAG() \
 233   do                                                                         \
 234     { int __res                                                              \
 235         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 236                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 237       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 238         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 239     }                                                                        \
 240   while (0)
 241 #define THREAD_GSCOPE_SET_FLAG() \
 242   do                                                                         \
 243     {                                                                        \
 244       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 245       atomic_write_barrier ();                                               \
 246     }                                                                        \
 247   while (0)
 248 #define THREAD_GSCOPE_WAIT() \
 249   GL(dl_wait_lookup_done) ()
 250
 251 #endif /* __ASSEMBLER__ */
 252
 253 #endif  /* tls.h */