sysdeps/powerpc/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/PowerPC version.
   2    Copyright (C) 2003-2024 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    <https://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 # include <thread_pointer.h>
  30
  31 #else /* __ASSEMBLER__ */
  32 # include <tcb-offsets.h>
  33 # define __ASSEMBLY__
  34 # include <asm/ptrace.h>
  35 #endif /* __ASSEMBLER__ */
  36
  37 #ifndef __powerpc64__
  38 /* Register r2 (tp) is reserved by the ABI as "thread pointer". */
  39 # define PT_THREAD_POINTER PT_R2
  40
  41 #else /* __powerpc64__ */
  42 /* Register r13 (tp) is reserved by the ABI as "thread pointer". */
  43 # define PT_THREAD_POINTER PT_R13
  44 #endif /* __powerpc64__ */
  45
  46 #ifndef __ASSEMBLER__
  47
  48 /* Get system call information.  */
  49 # include <sysdep.h>
  50
  51 /* The TP points to the start of the thread blocks.  */
  52 # define TLS_DTV_AT_TP  1
  53 # define TLS_TCB_AT_TP  0
  54
  55 /* We use the multiple_threads field in the pthread struct */
  56 #define TLS_MULTIPLE_THREADS_IN_TCB     1
  57
  58 /* Get the thread descriptor definition.  */
  59 # include <nptl/descr.h>
  60
  61
  62 /* The stack_guard is accessed directly by GCC -fstack-protector code,
  63    so it is a part of public ABI.  The dtv and pointer_guard fields
  64    are private.  */
  65 typedef struct
  66 {
  67   /* Reservation for HWCAP3 and HWCAP4 data.  To be accessed by GCC in
  68      __builtin_cpu_supports(), so it is a part of the public ABI.  */
  69   uint64_t hwcap_extn;
  70   /* Reservation for HWCAP data.  To be accessed by GCC in
  71      __builtin_cpu_supports(), so it is a part of public ABI.  */
  72   uint64_t hwcap;
  73   /* Reservation for AT_PLATFORM data.  To be accessed by GCC in
  74      __builtin_cpu_is(), so it is a part of public ABI.  Since there
  75      are different ABIs for 32 and 64 bit, we put this field in a
  76      previously empty padding space for powerpc64.  */
  77 #ifndef __powerpc64__
  78   /* Padding to maintain alignment.  */
  79   uint32_t padding;
  80   uint32_t at_platform;
  81 #endif
  82   uint32_t __unused;
  83   /* Reservation for AT_PLATFORM data - powerpc64.  */
  84 #ifdef __powerpc64__
  85   uint32_t at_platform;
  86 #endif
  87   /* Reservation for Dynamic System Optimizer ABI.  */
  88   uintptr_t dso_slot2;
  89   uintptr_t dso_slot1;
  90   /* Reservation for tar register (ISA 2.07).  */
  91   uintptr_t tar_save;
  92   /* GCC split stack support.  */
  93   void *__private_ss;
  94   /* Reservation for the Event-Based Branching ABI.  */
  95   uintptr_t ebb_handler;
  96   uintptr_t ebb_ctx_pointer;
  97   uintptr_t ebb_reserved1;
  98   uintptr_t ebb_reserved2;
  99   uintptr_t pointer_guard;
 100   uintptr_t stack_guard;
 101   dtv_t *dtv;
 102 } tcbhead_t;
 103
 104 # include <hwcapinfo.h>
 105
 106 /* This is the size of the initial TCB.  */
 107 # define TLS_INIT_TCB_SIZE      0
 108
 109 /* This is the size of the TCB.  */
 110 # define TLS_TCB_SIZE           0
 111
 112 /* This is the size we need before TCB.  */
 113 # define TLS_PRE_TCB_SIZE \
 114   (sizeof (struct pthread)                                                    \
 115    + ((sizeof (tcbhead_t) + __alignof (struct pthread) - 1)                   \
 116       & ~(__alignof (struct pthread) - 1)))
 117
 118 /* The following assumes that TP (R2 or R13) points to the end of the
 119    TCB + 0x7000 (per the ABI).  This implies that TCB address is
 120    TP - 0x7000.  As we define TLS_DTV_AT_TP we can
 121    assume that the pthread struct is allocated immediately ahead of the
 122    TCB.  This implies that the pthread_descr address is
 123    TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
 124 # define TLS_TCB_OFFSET 0x7000
 125
 126 /* Install the dtv pointer.  The pointer passed is to the element with
 127    index -1 which contain the length.  */
 128 # define INSTALL_DTV(tcbp, dtvp) \
 129   ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
 130
 131 /* Install new dtv for current thread.  */
 132 # define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
 133
 134 /* Return dtv of given thread descriptor.  */
 135 # define GET_DTV(tcbp)  (((tcbhead_t *) (tcbp))[-1].dtv)
 136
 137 /* Code to initially initialize the thread pointer.  This might need
 138    special attention since 'errno' is not yet available and if the
 139    operation can cause a failure 'errno' must not be touched.  */
 140 # define TLS_INIT_TP(tcbp) \
 141   ({                                                                          \
 142     __thread_register = (void *) (tcbp) + TLS_TCB_OFFSET;                     \
 143     THREAD_SET_HWCAP (__tcb.hwcap);                                           \
 144     THREAD_SET_HWCAP_EXTN (__tcb.hwcap_extn);                                 \
 145     THREAD_SET_AT_PLATFORM (__tcb.at_platform);                               \
 146     true;                                                                     \
 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].hwcap_extn) =         \
 155       THREAD_GET_HWCAP_EXTN ();                                               \
 156     (((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].at_platform) =        \
 157       THREAD_GET_AT_PLATFORM ();
 158
 159 /* Return the address of the dtv for the current thread.  */
 160 # define THREAD_DTV() \
 161     (((tcbhead_t *) (__thread_register - TLS_TCB_OFFSET))[-1].dtv)
 162
 163 /* Return the thread descriptor for the current thread.  */
 164 # define THREAD_SELF \
 165     ((struct pthread *) (__thread_register \
 166                          - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 167
 168 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 169 # define DB_THREAD_SELF                                                       \
 170   REGISTER (32, 32, PT_THREAD_POINTER * 4,                                    \
 171             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)                              \
 172   REGISTER (64, 64, PT_THREAD_POINTER * 8,                                    \
 173             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
 174
 175 # include <tcb-access.h>
 176
 177 /* Set the stack guard field in TCB head.  */
 178 # define THREAD_SET_STACK_GUARD(value) \
 179     (((tcbhead_t *) ((char *) __thread_register                               \
 180                      - TLS_TCB_OFFSET))[-1].stack_guard = (value))
 181 # define THREAD_COPY_STACK_GUARD(descr) \
 182     (((tcbhead_t *) ((char *) (descr)                                         \
 183                      + TLS_PRE_TCB_SIZE))[-1].stack_guard                     \
 184      = ((tcbhead_t *) ((char *) __thread_register                             \
 185                        - TLS_TCB_OFFSET))[-1].stack_guard)
 186
 187 /* Set the stack guard field in TCB head.  */
 188 # define THREAD_GET_POINTER_GUARD() \
 189     (((tcbhead_t *) ((char *) __thread_register                               \
 190                      - TLS_TCB_OFFSET))[-1].pointer_guard)
 191 # define THREAD_SET_POINTER_GUARD(value) \
 192     (THREAD_GET_POINTER_GUARD () = (value))
 193 # define THREAD_COPY_POINTER_GUARD(descr) \
 194     (((tcbhead_t *) ((char *) (descr)                                         \
 195                      + TLS_PRE_TCB_SIZE))[-1].pointer_guard                   \
 196      = THREAD_GET_POINTER_GUARD())
 197
 198 /* hwcap & hwcap_extn fields in TCB head.  */
 199 # define THREAD_GET_HWCAP() \
 200     (((tcbhead_t *) ((char *) __thread_register                               \
 201                      - TLS_TCB_OFFSET))[-1].hwcap)
 202 # define THREAD_GET_HWCAP_EXTN() \
 203     (((tcbhead_t *) ((char *) __thread_register                               \
 204                      - TLS_TCB_OFFSET))[-1].hwcap_extn)
 205 # define THREAD_SET_HWCAP(value) \
 206     (THREAD_GET_HWCAP () = (value))
 207 # define THREAD_SET_HWCAP_EXTN(value) \
 208     (THREAD_GET_HWCAP_EXTN () = (value))
 209
 210 /* at_platform field in TCB head.  */
 211 # define THREAD_GET_AT_PLATFORM() \
 212     (((tcbhead_t *) ((char *) __thread_register                               \
 213                      - TLS_TCB_OFFSET))[-1].at_platform)
 214 # define THREAD_SET_AT_PLATFORM(value) \
 215     (THREAD_GET_AT_PLATFORM () = (value))
 216
 217 /* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
 218    different value to mean unset l_tls_offset.  */
 219 # define NO_TLS_OFFSET          -1
 220
 221 /* Get and set the global scope generation counter in struct pthread.  */
 222 #define THREAD_GSCOPE_FLAG_UNUSED 0
 223 #define THREAD_GSCOPE_FLAG_USED   1
 224 #define THREAD_GSCOPE_FLAG_WAIT   2
 225 #define THREAD_GSCOPE_RESET_FLAG() \
 226   do                                                                         \
 227     { int __res                                                              \
 228         = atomic_exchange_release (&THREAD_SELF->header.gscope_flag,         \
 229                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 230       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 231         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 232     }                                                                        \
 233   while (0)
 234 #define THREAD_GSCOPE_SET_FLAG() \
 235   do                                                                         \
 236     {                                                                        \
 237       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 238       atomic_write_barrier ();                                               \
 239     }                                                                        \
 240   while (0)
 241
 242 #endif /* __ASSEMBLER__ */
 243
 244 #endif  /* tls.h */