Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 1 | /* |
| 2 | * net/tipc/ref.c: TIPC object registry code |
| 3 | * |
Per Liden | 593a5f2 | 2006-01-11 19:14:19 +0100 | [diff] [blame] | 4 | * Copyright (c) 1991-2006, Ericsson AB |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 5 | * Copyright (c) 2004-2005, Wind River Systems |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 6 | * All rights reserved. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions are met: |
Per Liden | 9ea1fd3 | 2006-01-11 13:30:43 +0100 | [diff] [blame] | 10 | * |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. Neither the names of the copyright holders nor the names of its |
| 17 | * contributors may be used to endorse or promote products derived from |
| 18 | * this software without specific prior written permission. |
| 19 | * |
| 20 | * Alternatively, this software may be distributed under the terms of the |
| 21 | * GNU General Public License ("GPL") version 2 as published by the Free |
| 22 | * Software Foundation. |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| 25 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| 28 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 29 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 30 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 31 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 32 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 33 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 34 | * POSSIBILITY OF SUCH DAMAGE. |
| 35 | */ |
| 36 | |
| 37 | #include "core.h" |
| 38 | #include "ref.h" |
| 39 | #include "port.h" |
| 40 | #include "subscr.h" |
| 41 | #include "name_distr.h" |
| 42 | #include "name_table.h" |
| 43 | #include "config.h" |
| 44 | #include "discover.h" |
| 45 | #include "bearer.h" |
| 46 | #include "node.h" |
| 47 | #include "bcast.h" |
| 48 | |
| 49 | /* |
| 50 | * Object reference table consists of 2**N entries. |
| 51 | * |
| 52 | * A used entry has object ptr != 0, reference == XXXX|own index |
| 53 | * (XXXX changes each time entry is acquired) |
| 54 | * A free entry has object ptr == 0, reference == YYYY|next free index |
| 55 | * (YYYY is one more than last used XXXX) |
| 56 | * |
| 57 | * Free list is initially chained from entry (2**N)-1 to entry 1. |
| 58 | * Entry 0 is not used to allow index 0 to indicate the end of the free list. |
| 59 | * |
| 60 | * Note: Any accidental reference of the form XXXX|0--0 won't match entry 0 |
| 61 | * because entry 0's reference field has the form XXXX|1--1. |
| 62 | */ |
| 63 | |
Sam Ravnborg | 1fc54d8 | 2006-03-20 22:36:47 -0800 | [diff] [blame^] | 64 | struct ref_table tipc_ref_table = { NULL }; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 65 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 66 | static rwlock_t ref_table_lock = RW_LOCK_UNLOCKED; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 67 | |
| 68 | /** |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 69 | * tipc_ref_table_init - create reference table for objects |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 70 | */ |
| 71 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 72 | int tipc_ref_table_init(u32 requested_size, u32 start) |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 73 | { |
| 74 | struct reference *table; |
| 75 | u32 sz = 1 << 4; |
| 76 | u32 index_mask; |
| 77 | int i; |
| 78 | |
| 79 | while (sz < requested_size) { |
| 80 | sz <<= 1; |
| 81 | } |
| 82 | table = (struct reference *)vmalloc(sz * sizeof(struct reference)); |
| 83 | if (table == NULL) |
| 84 | return -ENOMEM; |
| 85 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 86 | write_lock_bh(&ref_table_lock); |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 87 | index_mask = sz - 1; |
| 88 | for (i = sz - 1; i >= 0; i--) { |
Sam Ravnborg | 1fc54d8 | 2006-03-20 22:36:47 -0800 | [diff] [blame^] | 89 | table[i].object = NULL; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 90 | table[i].lock = SPIN_LOCK_UNLOCKED; |
| 91 | table[i].data.next_plus_upper = (start & ~index_mask) + i - 1; |
| 92 | } |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 93 | tipc_ref_table.entries = table; |
| 94 | tipc_ref_table.index_mask = index_mask; |
| 95 | tipc_ref_table.first_free = sz - 1; |
| 96 | tipc_ref_table.last_free = 1; |
| 97 | write_unlock_bh(&ref_table_lock); |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 98 | return TIPC_OK; |
| 99 | } |
| 100 | |
| 101 | /** |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 102 | * tipc_ref_table_stop - destroy reference table for objects |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 103 | */ |
| 104 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 105 | void tipc_ref_table_stop(void) |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 106 | { |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 107 | if (!tipc_ref_table.entries) |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 108 | return; |
| 109 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 110 | vfree(tipc_ref_table.entries); |
Sam Ravnborg | 1fc54d8 | 2006-03-20 22:36:47 -0800 | [diff] [blame^] | 111 | tipc_ref_table.entries = NULL; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 112 | } |
| 113 | |
| 114 | /** |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 115 | * tipc_ref_acquire - create reference to an object |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 116 | * |
| 117 | * Return a unique reference value which can be translated back to the pointer |
| 118 | * 'object' at a later time. Also, pass back a pointer to the lock protecting |
| 119 | * the object, but without locking it. |
| 120 | */ |
| 121 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 122 | u32 tipc_ref_acquire(void *object, spinlock_t **lock) |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 123 | { |
| 124 | struct reference *entry; |
| 125 | u32 index; |
| 126 | u32 index_mask; |
| 127 | u32 next_plus_upper; |
| 128 | u32 reference = 0; |
| 129 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 130 | assert(tipc_ref_table.entries && object); |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 131 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 132 | write_lock_bh(&ref_table_lock); |
| 133 | if (tipc_ref_table.first_free) { |
| 134 | index = tipc_ref_table.first_free; |
| 135 | entry = &(tipc_ref_table.entries[index]); |
| 136 | index_mask = tipc_ref_table.index_mask; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 137 | /* take lock in case a previous user of entry still holds it */ |
| 138 | spin_lock_bh(&entry->lock); |
| 139 | next_plus_upper = entry->data.next_plus_upper; |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 140 | tipc_ref_table.first_free = next_plus_upper & index_mask; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 141 | reference = (next_plus_upper & ~index_mask) + index; |
| 142 | entry->data.reference = reference; |
| 143 | entry->object = object; |
| 144 | if (lock != 0) |
| 145 | *lock = &entry->lock; |
| 146 | spin_unlock_bh(&entry->lock); |
| 147 | } |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 148 | write_unlock_bh(&ref_table_lock); |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 149 | return reference; |
| 150 | } |
| 151 | |
| 152 | /** |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 153 | * tipc_ref_discard - invalidate references to an object |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 154 | * |
| 155 | * Disallow future references to an object and free up the entry for re-use. |
| 156 | * Note: The entry's spin_lock may still be busy after discard |
| 157 | */ |
| 158 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 159 | void tipc_ref_discard(u32 ref) |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 160 | { |
| 161 | struct reference *entry; |
| 162 | u32 index; |
| 163 | u32 index_mask; |
| 164 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 165 | assert(tipc_ref_table.entries); |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 166 | assert(ref != 0); |
| 167 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 168 | write_lock_bh(&ref_table_lock); |
| 169 | index_mask = tipc_ref_table.index_mask; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 170 | index = ref & index_mask; |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 171 | entry = &(tipc_ref_table.entries[index]); |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 172 | assert(entry->object != 0); |
| 173 | assert(entry->data.reference == ref); |
| 174 | |
| 175 | /* mark entry as unused */ |
Sam Ravnborg | 1fc54d8 | 2006-03-20 22:36:47 -0800 | [diff] [blame^] | 176 | entry->object = NULL; |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 177 | if (tipc_ref_table.first_free == 0) |
| 178 | tipc_ref_table.first_free = index; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 179 | else |
| 180 | /* next_plus_upper is always XXXX|0--0 for last free entry */ |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 181 | tipc_ref_table.entries[tipc_ref_table.last_free].data.next_plus_upper |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 182 | |= index; |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 183 | tipc_ref_table.last_free = index; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 184 | |
| 185 | /* increment upper bits of entry to invalidate subsequent references */ |
| 186 | entry->data.next_plus_upper = (ref & ~index_mask) + (index_mask + 1); |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 187 | write_unlock_bh(&ref_table_lock); |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 188 | } |
| 189 | |