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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/connector/cn_queue.c
Initial import
Diffstat (limited to 'drivers/connector/cn_queue.c')
-rw-r--r--drivers/connector/cn_queue.c161
1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/connector/cn_queue.c b/drivers/connector/cn_queue.c
new file mode 100644
index 000000000..1f8bf054d
--- /dev/null
+++ b/drivers/connector/cn_queue.c
@@ -0,0 +1,161 @@
+/*
+ * 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) {
+ pr_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)) {
+ pr_info("Waiting for %s to become free: refcnt=%d.\n",
+ dev->name, atomic_read(&dev->refcnt));
+ msleep(1000);
+ }
+
+ kfree(dev);
+ dev = NULL;
+}