148 lines
3.2 KiB
C
148 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* cn_queue.c
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*
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* 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
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* All rights reserved.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/workqueue.h>
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#include <linux/spinlock.h>
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#include <linux/slab.h>
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#include <linux/skbuff.h>
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#include <linux/suspend.h>
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#include <linux/connector.h>
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#include <linux/delay.h>
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static struct cn_callback_entry *
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cn_queue_alloc_callback_entry(struct cn_queue_dev *dev, const char *name,
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const struct cb_id *id,
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void (*callback)(struct cn_msg *,
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struct netlink_skb_parms *))
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{
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struct cn_callback_entry *cbq;
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cbq = kzalloc(sizeof(*cbq), GFP_KERNEL);
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if (!cbq) {
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pr_err("Failed to create new callback queue.\n");
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return NULL;
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}
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refcount_set(&cbq->refcnt, 1);
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atomic_inc(&dev->refcnt);
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cbq->pdev = dev;
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snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name);
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memcpy(&cbq->id.id, id, sizeof(struct cb_id));
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cbq->callback = callback;
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return cbq;
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}
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void cn_queue_release_callback(struct cn_callback_entry *cbq)
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{
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if (!refcount_dec_and_test(&cbq->refcnt))
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return;
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atomic_dec(&cbq->pdev->refcnt);
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kfree(cbq);
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}
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int cn_cb_equal(const struct cb_id *i1, const struct cb_id *i2)
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{
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return ((i1->idx == i2->idx) && (i1->val == i2->val));
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}
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int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
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const struct cb_id *id,
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void (*callback)(struct cn_msg *,
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struct netlink_skb_parms *))
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{
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struct cn_callback_entry *cbq, *__cbq;
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int found = 0;
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cbq = cn_queue_alloc_callback_entry(dev, name, id, callback);
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if (!cbq)
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return -ENOMEM;
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spin_lock_bh(&dev->queue_lock);
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list_for_each_entry(__cbq, &dev->queue_list, callback_entry) {
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if (cn_cb_equal(&__cbq->id.id, id)) {
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found = 1;
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break;
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}
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}
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if (!found)
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list_add_tail(&cbq->callback_entry, &dev->queue_list);
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spin_unlock_bh(&dev->queue_lock);
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if (found) {
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cn_queue_release_callback(cbq);
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return -EINVAL;
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}
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cbq->seq = 0;
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cbq->group = cbq->id.id.idx;
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return 0;
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}
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void cn_queue_del_callback(struct cn_queue_dev *dev, const struct cb_id *id)
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{
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struct cn_callback_entry *cbq, *n;
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int found = 0;
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spin_lock_bh(&dev->queue_lock);
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list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) {
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if (cn_cb_equal(&cbq->id.id, id)) {
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list_del(&cbq->callback_entry);
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found = 1;
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break;
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}
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}
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spin_unlock_bh(&dev->queue_lock);
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if (found)
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cn_queue_release_callback(cbq);
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}
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struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *nls)
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{
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struct cn_queue_dev *dev;
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dev = kzalloc(sizeof(*dev), GFP_KERNEL);
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if (!dev)
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return NULL;
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snprintf(dev->name, sizeof(dev->name), "%s", name);
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atomic_set(&dev->refcnt, 0);
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INIT_LIST_HEAD(&dev->queue_list);
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spin_lock_init(&dev->queue_lock);
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dev->nls = nls;
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return dev;
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}
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void cn_queue_free_dev(struct cn_queue_dev *dev)
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{
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struct cn_callback_entry *cbq, *n;
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spin_lock_bh(&dev->queue_lock);
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list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
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list_del(&cbq->callback_entry);
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spin_unlock_bh(&dev->queue_lock);
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while (atomic_read(&dev->refcnt)) {
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pr_info("Waiting for %s to become free: refcnt=%d.\n",
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dev->name, atomic_read(&dev->refcnt));
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msleep(1000);
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}
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kfree(dev);
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dev = NULL;
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}
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