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path: root/drivers/connector/cn_queue.c
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Diffstat (limited to 'drivers/connector/cn_queue.c')
-rw-r--r--drivers/connector/cn_queue.c75
1 files changed, 8 insertions, 67 deletions
diff --git a/drivers/connector/cn_queue.c b/drivers/connector/cn_queue.c
index 210338ea222f..81270d221e5a 100644
--- a/drivers/connector/cn_queue.c
+++ b/drivers/connector/cn_queue.c
@@ -31,48 +31,6 @@
31#include <linux/connector.h> 31#include <linux/connector.h>
32#include <linux/delay.h> 32#include <linux/delay.h>
33 33
34
35/*
36 * This job is sent to the kevent workqueue.
37 * While no event is once sent to any callback, the connector workqueue
38 * is not created to avoid a useless waiting kernel task.
39 * Once the first event is received, we create this dedicated workqueue which
40 * is necessary because the flow of data can be high and we don't want
41 * to encumber keventd with that.
42 */
43static void cn_queue_create(struct work_struct *work)
44{
45 struct cn_queue_dev *dev;
46
47 dev = container_of(work, struct cn_queue_dev, wq_creation);
48
49 dev->cn_queue = create_singlethread_workqueue(dev->name);
50 /* If we fail, we will use keventd for all following connector jobs */
51 WARN_ON(!dev->cn_queue);
52}
53
54/*
55 * Queue a data sent to a callback.
56 * If the connector workqueue is already created, we queue the job on it.
57 * Otherwise, we queue the job to kevent and queue the connector workqueue
58 * creation too.
59 */
60int queue_cn_work(struct cn_callback_entry *cbq, struct work_struct *work)
61{
62 struct cn_queue_dev *pdev = cbq->pdev;
63
64 if (likely(pdev->cn_queue))
65 return queue_work(pdev->cn_queue, work);
66
67 /* Don't create the connector workqueue twice */
68 if (atomic_inc_return(&pdev->wq_requested) == 1)
69 schedule_work(&pdev->wq_creation);
70 else
71 atomic_dec(&pdev->wq_requested);
72
73 return schedule_work(work);
74}
75
76void cn_queue_wrapper(struct work_struct *work) 34void cn_queue_wrapper(struct work_struct *work)
77{ 35{
78 struct cn_callback_entry *cbq = 36 struct cn_callback_entry *cbq =
@@ -111,11 +69,7 @@ cn_queue_alloc_callback_entry(char *name, struct cb_id *id,
111 69
112static void cn_queue_free_callback(struct cn_callback_entry *cbq) 70static void cn_queue_free_callback(struct cn_callback_entry *cbq)
113{ 71{
114 /* The first jobs have been sent to kevent, flush them too */ 72 flush_workqueue(cbq->pdev->cn_queue);
115 flush_scheduled_work();
116 if (cbq->pdev->cn_queue)
117 flush_workqueue(cbq->pdev->cn_queue);
118
119 kfree(cbq); 73 kfree(cbq);
120} 74}
121 75
@@ -193,11 +147,14 @@ struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls)
193 atomic_set(&dev->refcnt, 0); 147 atomic_set(&dev->refcnt, 0);
194 INIT_LIST_HEAD(&dev->queue_list); 148 INIT_LIST_HEAD(&dev->queue_list);
195 spin_lock_init(&dev->queue_lock); 149 spin_lock_init(&dev->queue_lock);
196 init_waitqueue_head(&dev->wq_created);
197 150
198 dev->nls = nls; 151 dev->nls = nls;
199 152
200 INIT_WORK(&dev->wq_creation, cn_queue_create); 153 dev->cn_queue = alloc_ordered_workqueue(dev->name, 0);
154 if (!dev->cn_queue) {
155 kfree(dev);
156 return NULL;
157 }
201 158
202 return dev; 159 return dev;
203} 160}
@@ -205,25 +162,9 @@ struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls)
205void cn_queue_free_dev(struct cn_queue_dev *dev) 162void cn_queue_free_dev(struct cn_queue_dev *dev)
206{ 163{
207 struct cn_callback_entry *cbq, *n; 164 struct cn_callback_entry *cbq, *n;
208 long timeout;
209 DEFINE_WAIT(wait);
210
211 /* Flush the first pending jobs queued on kevent */
212 flush_scheduled_work();
213
214 /* If the connector workqueue creation is still pending, wait for it */
215 prepare_to_wait(&dev->wq_created, &wait, TASK_UNINTERRUPTIBLE);
216 if (atomic_read(&dev->wq_requested) && !dev->cn_queue) {
217 timeout = schedule_timeout(HZ * 2);
218 if (!timeout && !dev->cn_queue)
219 WARN_ON(1);
220 }
221 finish_wait(&dev->wq_created, &wait);
222 165
223 if (dev->cn_queue) { 166 flush_workqueue(dev->cn_queue);
224 flush_workqueue(dev->cn_queue); 167 destroy_workqueue(dev->cn_queue);
225 destroy_workqueue(dev->cn_queue);
226 }
227 168
228 spin_lock_bh(&dev->queue_lock); 169 spin_lock_bh(&dev->queue_lock);
229 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) 170 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)