ia64/linux-2.6.18-xen.hg

view drivers/connector/cn_queue.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
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 */
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>
34 void cn_queue_wrapper(void *data)
35 {
36 struct cn_callback_data *d = data;
38 d->callback(d->callback_priv);
40 d->destruct_data(d->ddata);
41 d->ddata = NULL;
43 kfree(d->free);
44 }
46 static struct cn_callback_entry *cn_queue_alloc_callback_entry(char *name, struct cb_id *id, void (*callback)(void *))
47 {
48 struct cn_callback_entry *cbq;
50 cbq = kzalloc(sizeof(*cbq), GFP_KERNEL);
51 if (!cbq) {
52 printk(KERN_ERR "Failed to create new callback queue.\n");
53 return NULL;
54 }
56 snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name);
57 memcpy(&cbq->id.id, id, sizeof(struct cb_id));
58 cbq->data.callback = callback;
60 INIT_WORK(&cbq->work, &cn_queue_wrapper, &cbq->data);
61 return cbq;
62 }
64 static void cn_queue_free_callback(struct cn_callback_entry *cbq)
65 {
66 cancel_delayed_work(&cbq->work);
67 flush_workqueue(cbq->pdev->cn_queue);
69 kfree(cbq);
70 }
72 int cn_cb_equal(struct cb_id *i1, struct cb_id *i2)
73 {
74 return ((i1->idx == i2->idx) && (i1->val == i2->val));
75 }
77 int cn_queue_add_callback(struct cn_queue_dev *dev, char *name, struct cb_id *id, void (*callback)(void *))
78 {
79 struct cn_callback_entry *cbq, *__cbq;
80 int found = 0;
82 cbq = cn_queue_alloc_callback_entry(name, id, callback);
83 if (!cbq)
84 return -ENOMEM;
86 atomic_inc(&dev->refcnt);
87 cbq->pdev = dev;
89 spin_lock_bh(&dev->queue_lock);
90 list_for_each_entry(__cbq, &dev->queue_list, callback_entry) {
91 if (cn_cb_equal(&__cbq->id.id, id)) {
92 found = 1;
93 break;
94 }
95 }
96 if (!found)
97 list_add_tail(&cbq->callback_entry, &dev->queue_list);
98 spin_unlock_bh(&dev->queue_lock);
100 if (found) {
101 atomic_dec(&dev->refcnt);
102 cn_queue_free_callback(cbq);
103 return -EINVAL;
104 }
106 cbq->nls = dev->nls;
107 cbq->seq = 0;
108 cbq->group = cbq->id.id.idx;
110 return 0;
111 }
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;
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);
128 if (found) {
129 cn_queue_free_callback(cbq);
130 atomic_dec(&dev->refcnt);
131 }
132 }
134 struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls)
135 {
136 struct cn_queue_dev *dev;
138 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
139 if (!dev)
140 return NULL;
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);
147 dev->nls = nls;
148 dev->netlink_groups = 0;
150 dev->cn_queue = create_workqueue(dev->name);
151 if (!dev->cn_queue) {
152 kfree(dev);
153 return NULL;
154 }
156 return dev;
157 }
159 void cn_queue_free_dev(struct cn_queue_dev *dev)
160 {
161 struct cn_callback_entry *cbq, *n;
163 flush_workqueue(dev->cn_queue);
164 destroy_workqueue(dev->cn_queue);
166 spin_lock_bh(&dev->queue_lock);
167 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
168 list_del(&cbq->callback_entry);
169 spin_unlock_bh(&dev->queue_lock);
171 while (atomic_read(&dev->refcnt)) {
172 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
173 dev->name, atomic_read(&dev->refcnt));
174 msleep(1000);
175 }
177 kfree(dev);
178 dev = NULL;
179 }