yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame] | 1 | /* Definitions for thread-local data handling. linuxthreads/PPC version. |
| 2 | Copyright (C) 2003, 2005 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, write to the Free |
| 17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 18 | 02111-1307 USA. */ |
| 19 | |
| 20 | #ifndef _TLS_H |
| 21 | #define _TLS_H |
| 22 | |
| 23 | #ifndef __ASSEMBLER__ |
| 24 | |
| 25 | # include <pt-machine.h> |
| 26 | # include <stdbool.h> |
| 27 | # include <stddef.h> |
| 28 | |
| 29 | /* Type for the dtv. */ |
| 30 | typedef union dtv |
| 31 | { |
| 32 | size_t counter; |
| 33 | struct |
| 34 | { |
| 35 | void *val; |
| 36 | bool is_static; |
| 37 | } pointer; |
| 38 | } dtv_t; |
| 39 | |
| 40 | #else /* __ASSEMBLER__ */ |
| 41 | # include <tcb-offsets.h> |
| 42 | #endif /* __ASSEMBLER__ */ |
| 43 | |
| 44 | #ifdef HAVE_TLS_SUPPORT |
| 45 | |
| 46 | /* Signal that TLS support is available. */ |
| 47 | # define USE_TLS 1 |
| 48 | |
| 49 | # ifndef __ASSEMBLER__ |
| 50 | |
| 51 | /* This layout is actually wholly private and not affected by the ABI. |
| 52 | Nor does it overlap the pthread data structure, so we need nothing |
| 53 | extra here at all. */ |
| 54 | typedef struct |
| 55 | { |
| 56 | dtv_t *dtv; |
| 57 | } tcbhead_t; |
| 58 | |
| 59 | /* This is the size of the initial TCB. */ |
| 60 | # define TLS_INIT_TCB_SIZE 0 |
| 61 | |
| 62 | /* Alignment requirements for the initial TCB. */ |
| 63 | # define TLS_INIT_TCB_ALIGN __alignof__ (struct _pthread_descr_struct) |
| 64 | |
| 65 | /* This is the size of the TCB. */ |
| 66 | # define TLS_TCB_SIZE 0 |
| 67 | |
| 68 | /* Alignment requirements for the TCB. */ |
| 69 | # define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct) |
| 70 | |
| 71 | /* This is the size we need before TCB. */ |
| 72 | # define TLS_PRE_TCB_SIZE \ |
| 73 | (sizeof (struct _pthread_descr_struct) \ |
| 74 | + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1))) |
| 75 | |
| 76 | /* The following assumes that TP (R2 or R13) is points to the end of the |
| 77 | TCB + 0x7000 (per the ABI). This implies that TCB address is |
| 78 | TP - 0x7000. As we define TLS_DTV_AT_TP we can |
| 79 | assume that the pthread_descr is allocated immediately ahead of the |
| 80 | TCB. This implies that the pthread_descr address is |
| 81 | TP - (TLS_PRE_TCB_SIZE + 0x7000). */ |
| 82 | #define TLS_TCB_OFFSET 0x7000 |
| 83 | |
| 84 | /* The DTV is allocated at the TP; the TCB is placed elsewhere. */ |
| 85 | /* This is not really true for powerpc64. We are following alpha |
| 86 | where the DTV pointer is first doubleword in the TCB. */ |
| 87 | # define TLS_DTV_AT_TP 1 |
| 88 | |
| 89 | /* Install the dtv pointer. The pointer passed is to the element with |
| 90 | index -1 which contain the length. */ |
| 91 | # define INSTALL_DTV(TCBP, DTVP) \ |
| 92 | (((tcbhead_t *) (TCBP))[-1].dtv = (DTVP) + 1) |
| 93 | |
| 94 | /* Install new dtv for current thread. */ |
| 95 | # define INSTALL_NEW_DTV(DTV) (THREAD_DTV() = (DTV)) |
| 96 | |
| 97 | /* Return dtv of given thread descriptor. */ |
| 98 | # define GET_DTV(TCBP) (((tcbhead_t *) (TCBP))[-1].dtv) |
| 99 | |
| 100 | /* We still need this define so that tcb-offsets.sym can override it and |
| 101 | use THREAD_SELF to generate MULTIPLE_THREADS_OFFSET. */ |
| 102 | # define __thread_register ((void *) __thread_self) |
| 103 | |
| 104 | /* Code to initially initialize the thread pointer. This might need |
| 105 | special attention since 'errno' is not yet available and if the |
| 106 | operation can cause a failure 'errno' must not be touched. |
| 107 | |
| 108 | The global register variable is declared in pt-machine.h with the |
| 109 | wrong type, so we need some extra casts to get the desired result. |
| 110 | This avoids a lvalue cast that gcc-3.4 does not like. */ |
| 111 | # define TLS_INIT_TP(TCBP, SECONDCALL) \ |
| 112 | (__thread_self = (struct _pthread_descr_struct *) \ |
| 113 | ((void *) (TCBP) + TLS_TCB_OFFSET), NULL) |
| 114 | |
| 115 | /* Return the address of the dtv for the current thread. */ |
| 116 | # define THREAD_DTV() \ |
| 117 | (((tcbhead_t *) ((void *) __thread_self - TLS_TCB_OFFSET))[-1].dtv) |
| 118 | |
| 119 | /* Return the thread descriptor for the current thread. */ |
| 120 | # undef THREAD_SELF |
| 121 | # define THREAD_SELF \ |
| 122 | ((pthread_descr) (__thread_register \ |
| 123 | - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)) |
| 124 | |
| 125 | # undef INIT_THREAD_SELF |
| 126 | # define INIT_THREAD_SELF(DESCR, NR) \ |
| 127 | (__thread_self = (struct _pthread_descr_struct *)((void *) (DESCR) \ |
| 128 | + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)) |
| 129 | |
| 130 | /* Make sure we have the p_multiple_threads member in the thread structure. |
| 131 | See below. */ |
| 132 | # define TLS_MULTIPLE_THREADS_IN_TCB 1 |
| 133 | |
| 134 | /* Get the thread descriptor definition. */ |
| 135 | # include <linuxthreads/descr.h> |
| 136 | |
| 137 | /* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some |
| 138 | different value to mean unset l_tls_offset. */ |
| 139 | # define NO_TLS_OFFSET -1 |
| 140 | |
| 141 | # endif /* __ASSEMBLER__ */ |
| 142 | |
| 143 | #elif !defined __ASSEMBLER__ |
| 144 | |
| 145 | /* This overlaps the start of the pthread_descr. System calls |
| 146 | and such use this to find the multiple_threads flag and need |
| 147 | to use the same offset relative to the thread register in both |
| 148 | single-threaded and multi-threaded code. */ |
| 149 | typedef struct |
| 150 | { |
| 151 | void *tcb; /* Never used. */ |
| 152 | dtv_t *dtv; /* Never used. */ |
| 153 | void *self; /* Used only if multithreaded, and rarely. */ |
| 154 | int multiple_threads; /* Only this member is really used. */ |
| 155 | } tcbhead_t; |
| 156 | |
| 157 | #define NONTLS_INIT_TP \ |
| 158 | do { \ |
| 159 | static const tcbhead_t nontls_init_tp = { .multiple_threads = 0 }; \ |
| 160 | __thread_self = (__typeof (__thread_self)) &nontls_init_tp; \ |
| 161 | } while (0) |
| 162 | |
| 163 | #endif /* HAVE_TLS_SUPPORT */ |
| 164 | |
| 165 | #endif /* tls.h */ |