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Diffstat (limited to 'linuxthreads/sysdeps/mips/tls.h')
| -rw-r--r-- | linuxthreads/sysdeps/mips/tls.h | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/linuxthreads/sysdeps/mips/tls.h b/linuxthreads/sysdeps/mips/tls.h new file mode 100644 index 0000000000..be4478db43 --- /dev/null +++ b/linuxthreads/sysdeps/mips/tls.h @@ -0,0 +1,170 @@ +/* Definitions for thread-local data handling. linuxthreads/MIPS version. + Copyright (C) 2005 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#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; + +# define READ_THREAD_POINTER() \ + ({ void *__result; \ + asm volatile (".set\tpush\n\t.set\tmips32r2\n\t" \ + "rdhwr\t%0, $29\n\t.set\tpop" : "=v" (__result)); \ + __result; }) + +#else /* __ASSEMBLER__ */ +# include <tcb-offsets.h> + +/* Note: rd must be $v1 to be ABI-conformant. */ +# define READ_THREAD_POINTER(rd) \ + .set push; \ + .set mips32r2; \ + rdhwr rd, $29; \ + .set pop +#endif /* __ASSEMBLER__ */ + +/* LinuxThreads can only use TLS if both floating stacks (in the MIPS case, + that means support for "rdhwr") 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, but + it hardly seems worth it. Use NPTL if you can. + + 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__ + +/* This layout is actually wholly private and not affected by the ABI. + Nor does it overlap the pthread data structure, so we need nothing + extra here at all. */ +typedef struct +{ + dtv_t *dtv; + void *private; +} tcbhead_t; + +/* This is the size of the initial TCB. */ +# define TLS_INIT_TCB_SIZE 0 + +/* Alignment requirements for the initial TCB. */ +# define TLS_INIT_TCB_ALIGN __alignof__ (struct _pthread_descr_struct) + +/* This is the size of the TCB. */ +# define TLS_TCB_SIZE 0 + +/* Alignment requirements for the TCB. */ +# define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct) + +/* This is the size we need before TCB. */ +# define TLS_PRE_TCB_SIZE \ + (sizeof (struct _pthread_descr_struct) \ + + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1))) + +/* The thread pointer (in hardware register $29) points to the end of + the TCB + 0x7000, as for PowerPC. The pthread_descr structure is + immediately in front of the TCB. */ +#define TLS_TCB_OFFSET 0x7000 + +/* The DTV is allocated at the TP; the TCB is placed elsewhere. */ +/* This is not really true for powerpc64. We are following alpha + where the DTV pointer is first doubleword in the TCB. */ +# 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))[-1].dtv = (DTVP) + 1) + +/* Install new dtv for current thread. */ +# define INSTALL_NEW_DTV(DTV) (THREAD_DTV() = (DTV)) + +/* Return dtv of given thread descriptor. */ +# define GET_DTV(TCBP) (((tcbhead_t *) (TCBP))[-1].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 (set_thread_area, err, 1, \ + (char *) (tcbp) + TLS_TCB_OFFSET); \ + 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 *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv) + +/* Return the thread descriptor for the current thread. */ +# undef THREAD_SELF +# define THREAD_SELF \ + ((pthread_descr) (READ_THREAD_POINTER () \ + - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)) + +/* Get the thread descriptor definition. */ +# include <linuxthreads/descr.h> + +/* l_tls_offset == 0 is perfectly valid on MIPS, so we have to use some + different value to mean unset l_tls_offset. */ +# define NO_TLS_OFFSET -1 + +/* Initializing the thread pointer requires a syscall which may not be + available, so don't do it if we don't need to. */ +# define TLS_INIT_TP_EXPENSIVE 1 + +# endif /* __ASSEMBLER__ */ + +#endif /* HAVE_TLS_SUPPORT */ + +#endif /* tls.h */ |