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/* Definition for thread-local data handling. NPTL/OpenRISC version.
Copyright (C) 2022-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<https://www.gnu.org/licenses/>. */
#ifndef _TLS_H
#define _TLS_H 1
#include <dl-sysdep.h>
#ifndef __ASSEMBLER__
# include <stdbool.h>
# include <stddef.h>
# include <stdint.h>
# include <dl-dtv.h>
typedef struct
{
dtv_t *dtv;
void *__padding[3];
} tcbhead_t;
register tcbhead_t *__thread_self __asm__("r10");
# define TLS_MULTIPLE_THREADS_IN_TCB 1
/* Get system call information. */
# include <sysdep.h>
/* The TP points to the start of the TLS block.
As I understand it, this isn't strictly that "TP points to DTV" - it's
more where to place the TCB in the TLS block. This will place it in
the beginning.
Layout:
+-----+-----+----------------------+
| PRE | TCB | TLS MEMORY .. |
+-----+-----+----------------------+
^ r10 / TP
PRE is the struct pthread described below
TCB is tcbhead_t
TLS memory is where the TLS program sections are loaded
See _dl_allocate_tls_storage and __libc_setup_tls for more information. */
# define TLS_DTV_AT_TP 1
# define TLS_TCB_AT_TP 0
/* Get the thread descriptor definition. */
# include <nptl/descr.h>
/* Requirements for the TCB. */
# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
# define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
# define TLS_TCB_SIZE sizeof (tcbhead_t)
# define TLS_TCB_ALIGN __alignof__ (struct pthread)
/* This is the size of the TCB. */
/* This is the size we need before TCB.
To support THREAD_GETMEM with friends we want to have a
struct pthread available.
Yank it in infront of everything, I'm sure nobody will mind.
This memory is really allocated PRE the TLS block, so it's possible
to do ((char*)tlsblock) - TLS_PRE_TCB_SIZE to access it.
This is done for THREAD_SELF. */
# define TLS_PRE_TCB_SIZE sizeof (struct pthread)
/* Install the dtv pointer.
When called, dtvp is a pointer not the DTV per say (which should start
with the generation counter) but to the length of the DTV.
We can always index with -1, so we store dtvp[1]. */
# define INSTALL_DTV(tcbp, dtvp) \
(((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
/* Install new dtv for current thread
In a logicial world dtv here would also point to the length of the DTV.
However it does not, this time it points to the generation counter,
so just store it.
Note: -1 is still valid and contains the length. */
# define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
/* Return dtv of given thread descriptor. */
# define GET_DTV(tcbp) (((tcbhead_t *) (tcbp))->dtv)
/* Code to initially initialize the thread pointer.
Set TP to the address _after_ tcbhead_t. This will allow us
to change the size of tcbhead_t without having to re-link everything.
This has to return NULL on success (or a string with the failure text).
It's hard to fail this, so return NULL always. */
# define TLS_INIT_TP(tcbp) \
({__thread_self = ((tcbhead_t *)tcbp + 1); true;})
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) \
void *tp = ((char *) pd + TLS_PRE_TCB_SIZE + TLS_INIT_TCB_SIZE)
/* Return the address of the dtv for the current thread.
Dereference TP, offset to dtv - really straightforward.
Remember that we made TP point to after tcb, so we need to reverse that. */
# define THREAD_DTV() \
((((tcbhead_t *)__thread_self)-1)->dtv)
/* Return the thread descriptor for the current thread.
Return a pointer to the TLS_PRE area where we allocated space for
a struct pthread. Again, TP points to after tcbhead_t, compensate with
TLS_INIT_TCB_SIZE.
I regard this is a separate system from the "normal" TLS. */
# define THREAD_SELF \
((struct pthread *) ((char *) __thread_self - TLS_INIT_TCB_SIZE \
- TLS_PRE_TCB_SIZE))
/* Magic for libthread_db to know how to do THREAD_SELF. */
# define DB_THREAD_SELF \
REGISTER (32, 32, 10 * 4, - TLS_INIT_TCB_SIZE - TLS_PRE_TCB_SIZE)
# include <tcb-access.h>
/* Access to data in the thread descriptor is easy. */
#define THREAD_GETMEM(descr, member) \
descr->member
#define THREAD_GETMEM_NC(descr, member, idx) \
descr->member[idx]
#define THREAD_SETMEM(descr, member, value) \
descr->member = (value)
#define THREAD_SETMEM_NC(descr, member, idx, value) \
descr->member[idx] = (value)
/* Get and set the global scope generation counter in struct pthread. */
#define THREAD_GSCOPE_FLAG_UNUSED 0
#define THREAD_GSCOPE_FLAG_USED 1
#define THREAD_GSCOPE_FLAG_WAIT 2
#define THREAD_GSCOPE_RESET_FLAG() \
do \
{ \
int __res = atomic_exchange_release (&THREAD_SELF->header.gscope_flag,\
THREAD_GSCOPE_FLAG_UNUSED); \
if (__res == THREAD_GSCOPE_FLAG_WAIT) \
lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, \
LLL_PRIVATE); \
} \
while (0)
#define THREAD_GSCOPE_SET_FLAG() \
do \
{ \
THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
atomic_write_barrier (); \
} \
while (0)
#endif /* __ASSEMBLER__ */
#endif /* tls.h */
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