diff options
Diffstat (limited to 'libpthread/linuxthreads/sysdeps/arm/tls.h')
| -rw-r--r-- | libpthread/linuxthreads/sysdeps/arm/tls.h | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/sysdeps/arm/tls.h b/libpthread/linuxthreads/sysdeps/arm/tls.h new file mode 100644 index 000000000..df8d97009 --- /dev/null +++ b/libpthread/linuxthreads/sysdeps/arm/tls.h @@ -0,0 +1,171 @@ +/* Definitions for thread-local data handling. linuxthreads/ARM version. + Copyright (C) 2004 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 + <http://www.gnu.org/licenses/>. */ + +#ifndef _TLS_H +#define _TLS_H + +#ifndef __ASSEMBLER__ + +# include <stdbool.h> +# include <pt-machine.h> +# include <stddef.h> + +/* Type for the dtv. */ +typedef union dtv +{ + size_t counter; + struct + { + void *val; + bool is_static; + } pointer; +} dtv_t; + +typedef struct +{ + dtv_t *dtv; + + /* Reserved for the thread implementation. Unused in LinuxThreads. */ + void *private; +} tcbhead_t; +#endif + + +/* We can support TLS only if the floating-stack support is available. + However, we want to compile in the support and test at runtime whether + the running kernel can support it or not. To avoid bothering with the + TLS support code at all, use configure --without-tls. + + We need USE_TLS to be consistently defined, for ldsodefs.h conditionals. + But some of the code below can cause problems in building libpthread + (e.g. useldt.h will defined FLOATING_STACKS when it shouldn't). */ + +/* LinuxThreads can only support TLS if both floating stacks and support + from the tools are available. + + We have to define USE_TLS consistently, or ldsodefs.h will lay out types + differently between an NPTL build and a LinuxThreads build. It can be set + for libc.so and not libpthread.so, but only if we provide appropriate padding + in the _pthread_descr_struct. + + Currently nothing defines FLOATING_STACKS. We could assume this based on + kernel version once the TLS patches are available in kernel.org. + + To avoid bothering with the TLS support code at all, use configure + --without-tls. */ + +#if defined HAVE_TLS_SUPPORT \ + && (defined FLOATING_STACKS || !defined IS_IN_libpthread) + +/* Signal that TLS support is available. */ +# define USE_TLS 1 + +/* Include padding in _pthread_descr_struct so that libc can find p_errno, + if libpthread will only include the padding because of the !IS_IN_libpthread + check. */ +#ifndef FLOATING_STACKS +# define INCLUDE_TLS_PADDING 1 +#endif + +# ifndef __ASSEMBLER__ +/* Get system call information. */ +# include <sysdep.h> + +/* This is the size of the initial TCB. */ +# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t) + +/* Alignment requirements for the initial TCB. */ +# define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t) + +/* This is the size of the TCB. */ +# define TLS_TCB_SIZE sizeof (tcbhead_t) + +/* Alignment requirements for the TCB. */ +# define TLS_TCB_ALIGN __alignof__ (tcbhead_t) + +/* This is the size we need before TCB. */ +# define TLS_PRE_TCB_SIZE sizeof (struct _pthread_descr_struct) + +/* The DTV is allocated at the TP; the TCB is placed elsewhere. */ +# define TLS_DTV_AT_TP 1 + +/* Install the dtv pointer. The pointer passed is to the element with + index -1 which contain the length. */ +# define INSTALL_DTV(TCBP, DTVP) \ + (((tcbhead_t *) (TCBP))->dtv = (DTVP) + 1) + +/* Install new dtv for current thread. */ +# define INSTALL_NEW_DTV(DTV) \ + (((tcbhead_t *)__builtin_thread_pointer ())->dtv = (DTV)) + +/* Return dtv of given thread descriptor. */ +# define GET_DTV(TCBP) \ + (((tcbhead_t *) (TCBP))->dtv) + +/* Code to initially initialize the thread pointer. This might need + special attention since 'errno' is not yet available and if the + operation can cause a failure 'errno' must not be touched. */ +# define TLS_INIT_TP(TCBP, SECONDCALL) \ + ({ INTERNAL_SYSCALL_DECL (err); \ + long result_var; \ + result_var = INTERNAL_SYSCALL_ARM (set_tls, err, 1, (TCBP)); \ + INTERNAL_SYSCALL_ERROR_P (result_var, err) \ + ? "unknown error" : NULL; }) + +/* Return the address of the dtv for the current thread. */ +# define THREAD_DTV() \ + (((tcbhead_t *)__builtin_thread_pointer ())->dtv) + +/* Return the thread descriptor for the current thread. */ +# undef THREAD_SELF +# define THREAD_SELF \ + ((pthread_descr)__builtin_thread_pointer () - 1) + +# undef INIT_THREAD_SELF +# define INIT_THREAD_SELF(DESCR, NR) \ + TLS_INIT_TP ((struct _pthread_descr_struct *)(DESCR) + 1, 0) + +/* Get the thread descriptor definition. */ +# include <linuxthreads/descr.h> + +/* ??? Generic bits of LinuxThreads may call these macros with + DESCR set to NULL. We are expected to be able to reference + the "current" value. + + In our case, we'd really prefer to use DESCR, since lots of + PAL_code calls would be expensive. We can only trust that + the compiler does its job and unifies the multiple + __builtin_thread_pointer instances. */ + +#define THREAD_GETMEM(descr, member) \ + ((void) sizeof (descr), THREAD_SELF->member) +#define THREAD_GETMEM_NC(descr, member) \ + ((void) sizeof (descr), THREAD_SELF->member) +#define THREAD_SETMEM(descr, member, value) \ + ((void) sizeof (descr), THREAD_SELF->member = (value)) +#define THREAD_SETMEM_NC(descr, member, value) \ + ((void) sizeof (descr), THREAD_SELF->member = (value)) + +/* Initializing the thread pointer will generate a SIGILL if the syscall + is not available. */ +#define TLS_INIT_TP_EXPENSIVE 1 + +# endif /* HAVE_TLS_SUPPORT */ +#endif /* __ASSEMBLER__ */ + +#endif /* tls.h */ |