1  /* Definitions for thread-local data handling.  NPTL/C-SKY version.
       2     Copyright (C) 2018-2023 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  #ifndef __ASSEMBLER__
      23  
      24  # include <stdbool.h>
      25  # include <stddef.h>
      26  # include <stdint.h>
      27  # include <dl-dtv.h>
      28  
      29  /* Define r31 as thread pointer register.  */
      30  # define READ_THREAD_POINTER() \
      31    ({ void *__result;						\
      32       __asm__ __volatile__ ("mov %0, r31"			\
      33                             : "=r" (__result));			\
      34       __result; })
      35  
      36  #else
      37  /* Define r31 as thread pointer register.  */
      38  # define READ_THREAD_POINTER() \
      39  	mov r0, r31;
      40  #endif /* __ASSEMBLER__ */
      41  
      42  #ifndef __ASSEMBLER__
      43  
      44  /* Get system call information.  */
      45  # include <sysdep.h>
      46  
      47  /* The TP points to the start of the thread blocks.  */
      48  # define TLS_DTV_AT_TP	1
      49  # define TLS_TCB_AT_TP	0
      50  
      51  /* Get the thread descriptor definition.  */
      52  # include <nptl/descr.h>
      53  
      54  typedef struct
      55  {
      56    dtv_t *dtv;
      57    void *private;
      58  } tcbhead_t;
      59  
      60  /* This is the size of the initial TCB.  */
      61  # define TLS_INIT_TCB_SIZE	sizeof (tcbhead_t)
      62  
      63  /* This is the size of the TCB.  */
      64  # define TLS_TCB_SIZE		sizeof (tcbhead_t)
      65  
      66  /* This is the size we need before TCB.  */
      67  # define TLS_PRE_TCB_SIZE	sizeof (struct pthread)
      68  
      69  /* The thread pointer tp points to the end of the TCB.
      70     The pthread_descr structure is immediately in front of the TCB.  */
      71  # define TLS_TCB_OFFSET		0
      72  
      73  /* Install the dtv pointer.  The pointer passed is to the element with
      74     index -1 which contain the length.  */
      75  # define INSTALL_DTV(tcbp, dtvp) \
      76    (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
      77  
      78  /* Install new dtv for current thread.  */
      79  # define INSTALL_NEW_DTV(dtv) \
      80    (THREAD_DTV() = (dtv))
      81  
      82  /* Return dtv of given thread descriptor.  */
      83  # define GET_DTV(tcbp) \
      84    (((tcbhead_t *) (tcbp))->dtv)
      85  
      86  # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
      87  
      88  /* Code to initially initialize the thread pointer.  This might need
      89     special attention since 'errno' is not yet available and if the
      90     operation can cause a failure 'errno' must not be touched.  */
      91  # define TLS_INIT_TP(tcbp) \
      92    ({ long int result_var;						\
      93       result_var = INTERNAL_SYSCALL_CALL (set_thread_area, 		\
      94                      (char *) (tcbp) + TLS_TCB_OFFSET);			\
      95       !INTERNAL_SYSCALL_ERROR_P (result_var); })
      96  
      97  /* Return the address of the dtv for the current thread.  */
      98  # define THREAD_DTV() \
      99    (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))->dtv)
     100  
     101  /* Return the thread descriptor for the current thread.  */
     102  # undef THREAD_SELF
     103  # define THREAD_SELF \
     104    ((struct pthread *) (READ_THREAD_POINTER ()				\
     105  		       - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
     106  
     107  /* Magic for libthread_db to know how to do THREAD_SELF.  */
     108  # define DB_THREAD_SELF \
     109    CONST_THREAD_AREA (32, sizeof (struct pthread))
     110  
     111  # include <tcb-access.h>
     112  
     113  /* Get and set the global scope generation counter in struct pthread.  */
     114  # define THREAD_GSCOPE_FLAG_UNUSED 0
     115  # define THREAD_GSCOPE_FLAG_USED   1
     116  # define THREAD_GSCOPE_FLAG_WAIT   2
     117  # define THREAD_GSCOPE_RESET_FLAG() \
     118    do									      \
     119      { int __res								      \
     120  	= atomic_exchange_release (&THREAD_SELF->header.gscope_flag,	      \
     121  			       THREAD_GSCOPE_FLAG_UNUSED);		      \
     122        if (__res == THREAD_GSCOPE_FLAG_WAIT)				      \
     123  	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
     124      }									      \
     125    while (0)
     126  # define THREAD_GSCOPE_SET_FLAG() \
     127    do									      \
     128      {									      \
     129        THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;	      \
     130        atomic_write_barrier ();						      \
     131      }									      \
     132    while (0)
     133  
     134  #endif /* __ASSEMBLER__ */
     135  
     136  #endif /* tls.h */