From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/connector/cn_queue.c | 161 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 161 insertions(+) create mode 100644 drivers/connector/cn_queue.c (limited to 'drivers/connector/cn_queue.c') 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 + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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; +} -- cgit v1.2.3-54-g00ecf