sysdeps/loongarch/nptl/tls.h

   1 /* Definition for thread-local data handling.
   2    Copyright (C) 2022 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 _LOONGARCH_TLS_H
  20 #define _LOONGARCH_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 register void *__thread_self asm ("$tp");
  31 #define READ_THREAD_POINTER() ({ __thread_self; })
  32
  33 /* Get system call information.  */
  34 #include <sysdep.h>
  35
  36 /* The TP points to the start of the thread blocks.  */
  37 #define TLS_DTV_AT_TP 1
  38 #define TLS_TCB_AT_TP 0
  39
  40 /* Get the thread descriptor definition.  */
  41 #include <nptl/descr.h>
  42
  43 typedef struct
  44 {
  45   dtv_t *dtv;
  46   void *private;
  47 } tcbhead_t;
  48
  49 /* This is the size of the initial TCB.  Because our TCB is before the thread
  50    pointer, we don't need this.  */
  51 #define TLS_INIT_TCB_SIZE 0
  52
  53 /* Alignment requirements for the initial TCB.  */
  54 #define TLS_INIT_TCB_ALIGN __alignof__(struct pthread)
  55
  56 /* This is the size of the TCB.  Because our TCB is before the thread
  57    pointer, we don't need this.  */
  58 #define TLS_TCB_SIZE 0
  59
  60 /* Alignment requirements for the TCB.  */
  61 #define TLS_TCB_ALIGN __alignof__(struct pthread)
  62
  63 /* This is the size we need before TCB - actually, it includes the TCB.  */
  64 #define TLS_PRE_TCB_SIZE \
  65   (sizeof (struct pthread) \
  66    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  67
  68 /* The thread pointer tp points to the end of the TCB.
  69    The pthread_descr structure is immediately in front of the TCB.  */
  70 #define TLS_TCB_OFFSET 0
  71
  72 /* Install the dtv pointer.  The pointer passed is to the element with
  73    index -1 which contain the length.  */
  74 #define INSTALL_DTV(tcbp, dtvp) (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1)
  75
  76 /* Install new dtv for current thread.  */
  77 #define INSTALL_NEW_DTV(dtv) (THREAD_DTV () = (dtv))
  78
  79 /* Return dtv of given thread descriptor.  */
  80 #define GET_DTV(tcbp) (((tcbhead_t *) (tcbp))[-1].dtv)
  81
  82 /* Code to initially initialize the thread pointer.  */
  83 #define TLS_INIT_TP(tcbp) \
  84   ({ \
  85     __thread_self = (char *) tcbp + TLS_TCB_OFFSET; \
  86     NULL; \
  87   })
  88
  89 /* Return the address of the dtv for the current thread.  */
  90 #define THREAD_DTV() \
  91   (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
  92
  93 /* Return the thread descriptor for the current thread.  */
  94 #define THREAD_SELF \
  95   ((struct pthread *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET \
  96                        - TLS_PRE_TCB_SIZE))
  97
  98 /* Value passed to 'clone' for initialization of the thread register.  */
  99 #define TLS_DEFINE_INIT_TP(tp, pd) \
 100   void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
 101
 102 /* Informs libthread_db that the thread pointer is register 2, which is used
 103  * to know how to do THREAD_SELF.  */
 104 #define DB_THREAD_SELF \
 105   REGISTER (64, 64, 2 * 8, -TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
 106
 107 /* Access to data in the thread descriptor is easy.  */
 108 # include <tcb-access.h>
 109
 110 /* l_tls_offset == 0 is perfectly valid, so we have to use some different
 111    value to mean unset l_tls_offset.  */
 112 #define NO_TLS_OFFSET -1
 113
 114 /* Get and set the global scope generation counter in struct pthread.  */
 115 #define THREAD_GSCOPE_IN_TCB 1
 116 #define THREAD_GSCOPE_FLAG_UNUSED 0
 117 #define THREAD_GSCOPE_FLAG_USED 1
 118 #define THREAD_GSCOPE_FLAG_WAIT 2
 119 #define THREAD_GSCOPE_RESET_FLAG() \
 120   do \
 121     { \
 122       int __res = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag, \
 123                                        THREAD_GSCOPE_FLAG_UNUSED); \
 124       if (__res == THREAD_GSCOPE_FLAG_WAIT) \
 125         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
 126     } \
 127   while (0)
 128 #define THREAD_GSCOPE_SET_FLAG() \
 129   do \
 130     { \
 131       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
 132       atomic_write_barrier (); \
 133     } \
 134   while (0)
 135
 136 #endif /* __ASSEMBLER__ */
 137
 138 #endif /* tls.h */