1 /* 2 * cn_queue.c 3 * 4 * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru> 5 * All rights reserved. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 * 21 */ 22 23 #include <linux/kernel.h> 24 #include <linux/module.h> 25 #include <linux/list.h> 26 #include <linux/workqueue.h> 27 #include <linux/spinlock.h> 28 #include <linux/slab.h> 29 #include <linux/skbuff.h> 30 #include <linux/suspend.h> 31 #include <linux/connector.h> 32 #include <linux/delay.h> 33 34 void cn_queue_wrapper(struct work_struct *work) 35 { 36 struct cn_callback_entry *cbq = 37 container_of(work, struct cn_callback_entry, work); 38 struct cn_callback_data *d = &cbq->data; 39 40 d->callback(d->callback_priv); 41 42 d->destruct_data(d->ddata); 43 d->ddata = NULL; 44 45 kfree(d->free); 46 } 47 48 static struct cn_callback_entry *cn_queue_alloc_callback_entry(char *name, struct cb_id *id, void (*callback)(void *)) 49 { 50 struct cn_callback_entry *cbq; 51 52 cbq = kzalloc(sizeof(*cbq), GFP_KERNEL); 53 if (!cbq) { 54 printk(KERN_ERR "Failed to create new callback queue.\n"); 55 return NULL; 56 } 57 58 snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name); 59 memcpy(&cbq->id.id, id, sizeof(struct cb_id)); 60 cbq->data.callback = callback; 61 62 INIT_WORK(&cbq->work, &cn_queue_wrapper); 63 return cbq; 64 } 65 66 static void cn_queue_free_callback(struct cn_callback_entry *cbq) 67 { 68 flush_workqueue(cbq->pdev->cn_queue); 69 70 kfree(cbq); 71 } 72 73 int cn_cb_equal(struct cb_id *i1, struct cb_id *i2) 74 { 75 return ((i1->idx == i2->idx) && (i1->val == i2->val)); 76 } 77 78 int cn_queue_add_callback(struct cn_queue_dev *dev, char *name, struct cb_id *id, void (*callback)(void *)) 79 { 80 struct cn_callback_entry *cbq, *__cbq; 81 int found = 0; 82 83 cbq = cn_queue_alloc_callback_entry(name, id, callback); 84 if (!cbq) 85 return -ENOMEM; 86 87 atomic_inc(&dev->refcnt); 88 cbq->pdev = dev; 89 90 spin_lock_bh(&dev->queue_lock); 91 list_for_each_entry(__cbq, &dev->queue_list, callback_entry) { 92 if (cn_cb_equal(&__cbq->id.id, id)) { 93 found = 1; 94 break; 95 } 96 } 97 if (!found) 98 list_add_tail(&cbq->callback_entry, &dev->queue_list); 99 spin_unlock_bh(&dev->queue_lock); 100 101 if (found) { 102 cn_queue_free_callback(cbq); 103 atomic_dec(&dev->refcnt); 104 return -EINVAL; 105 } 106 107 cbq->seq = 0; 108 cbq->group = cbq->id.id.idx; 109 110 return 0; 111 } 112 113 void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id) 114 { 115 struct cn_callback_entry *cbq, *n; 116 int found = 0; 117 118 spin_lock_bh(&dev->queue_lock); 119 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) { 120 if (cn_cb_equal(&cbq->id.id, id)) { 121 list_del(&cbq->callback_entry); 122 found = 1; 123 break; 124 } 125 } 126 spin_unlock_bh(&dev->queue_lock); 127 128 if (found) { 129 cn_queue_free_callback(cbq); 130 atomic_dec(&dev->refcnt); 131 } 132 } 133 134 struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls) 135 { 136 struct cn_queue_dev *dev; 137 138 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 139 if (!dev) 140 return NULL; 141 142 snprintf(dev->name, sizeof(dev->name), "%s", name); 143 atomic_set(&dev->refcnt, 0); 144 INIT_LIST_HEAD(&dev->queue_list); 145 spin_lock_init(&dev->queue_lock); 146 147 dev->nls = nls; 148 149 dev->cn_queue = create_singlethread_workqueue(dev->name); 150 if (!dev->cn_queue) { 151 kfree(dev); 152 return NULL; 153 } 154 155 return dev; 156 } 157 158 void cn_queue_free_dev(struct cn_queue_dev *dev) 159 { 160 struct cn_callback_entry *cbq, *n; 161 162 flush_workqueue(dev->cn_queue); 163 destroy_workqueue(dev->cn_queue); 164 165 spin_lock_bh(&dev->queue_lock); 166 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) 167 list_del(&cbq->callback_entry); 168 spin_unlock_bh(&dev->queue_lock); 169 170 while (atomic_read(&dev->refcnt)) { 171 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", 172 dev->name, atomic_read(&dev->refcnt)); 173 msleep(1000); 174 } 175 176 kfree(dev); 177 dev = NULL; 178 } 179