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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 | /* * cn_queue.c * * 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net> * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/list.h> #include <linux/workqueue.h> #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/skbuff.h> #include <linux/suspend.h> #include <linux/connector.h> #include <linux/delay.h> static struct cn_callback_entry * cn_queue_alloc_callback_entry(struct cn_queue_dev *dev, const char *name, struct cb_id *id, void (*callback)(struct cn_msg *, struct netlink_skb_parms *)) { struct cn_callback_entry *cbq; cbq = kzalloc(sizeof(*cbq), GFP_KERNEL); if (!cbq) { printk(KERN_ERR "Failed to create new callback queue.\n"); return NULL; } atomic_set(&cbq->refcnt, 1); atomic_inc(&dev->refcnt); cbq->pdev = dev; snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name); memcpy(&cbq->id.id, id, sizeof(struct cb_id)); cbq->callback = callback; return cbq; } void cn_queue_release_callback(struct cn_callback_entry *cbq) { if (!atomic_dec_and_test(&cbq->refcnt)) return; atomic_dec(&cbq->pdev->refcnt); kfree(cbq); } int cn_cb_equal(struct cb_id *i1, struct cb_id *i2) { return ((i1->idx == i2->idx) && (i1->val == i2->val)); } int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name, struct cb_id *id, void (*callback)(struct cn_msg *, struct netlink_skb_parms *)) { struct cn_callback_entry *cbq, *__cbq; int found = 0; cbq = cn_queue_alloc_callback_entry(dev, name, id, callback); if (!cbq) return -ENOMEM; spin_lock_bh(&dev->queue_lock); list_for_each_entry(__cbq, &dev->queue_list, callback_entry) { if (cn_cb_equal(&__cbq->id.id, id)) { found = 1; break; } } if (!found) list_add_tail(&cbq->callback_entry, &dev->queue_list); spin_unlock_bh(&dev->queue_lock); if (found) { cn_queue_release_callback(cbq); return -EINVAL; } cbq->seq = 0; cbq->group = cbq->id.id.idx; return 0; } void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id) { struct cn_callback_entry *cbq, *n; int found = 0; spin_lock_bh(&dev->queue_lock); list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) { if (cn_cb_equal(&cbq->id.id, id)) { list_del(&cbq->callback_entry); found = 1; break; } } spin_unlock_bh(&dev->queue_lock); if (found) cn_queue_release_callback(cbq); } struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *nls) { struct cn_queue_dev *dev; dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) return NULL; snprintf(dev->name, sizeof(dev->name), "%s", name); atomic_set(&dev->refcnt, 0); INIT_LIST_HEAD(&dev->queue_list); spin_lock_init(&dev->queue_lock); dev->nls = nls; return dev; } void cn_queue_free_dev(struct cn_queue_dev *dev) { struct cn_callback_entry *cbq, *n; spin_lock_bh(&dev->queue_lock); list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) list_del(&cbq->callback_entry); spin_unlock_bh(&dev->queue_lock); while (atomic_read(&dev->refcnt)) { printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", dev->name, atomic_read(&dev->refcnt)); msleep(1000); } kfree(dev); dev = NULL; } |