2 * Copyright (C) 2003-2008 Takahiro Hirofuchi
3 * Copyright (C) 2015 Nobuo Iwata
5 * This is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
21 #include <linux/kthread.h>
22 #include <linux/export.h>
23 #include <linux/slab.h>
24 #include <linux/workqueue.h>
26 #include "usbip_common.h"
29 struct list_head node;
30 struct usbip_device *ud;
33 static DEFINE_SPINLOCK(event_lock);
34 static LIST_HEAD(event_list);
36 static void set_event(struct usbip_device *ud, unsigned long event)
40 spin_lock_irqsave(&ud->lock, flags);
42 spin_unlock_irqrestore(&ud->lock, flags);
45 static void unset_event(struct usbip_device *ud, unsigned long event)
49 spin_lock_irqsave(&ud->lock, flags);
51 spin_unlock_irqrestore(&ud->lock, flags);
54 static struct usbip_device *get_event(void)
56 struct usbip_event *ue = NULL;
57 struct usbip_device *ud = NULL;
60 spin_lock_irqsave(&event_lock, flags);
61 if (!list_empty(&event_list)) {
62 ue = list_first_entry(&event_list, struct usbip_event, node);
65 spin_unlock_irqrestore(&event_lock, flags);
74 static struct task_struct *worker_context;
76 static void event_handler(struct work_struct *work)
78 struct usbip_device *ud;
80 if (worker_context == NULL) {
81 worker_context = current;
84 while ((ud = get_event()) != NULL) {
85 usbip_dbg_eh("pending event %lx\n", ud->event);
87 mutex_lock(&ud->sysfs_lock);
89 * NOTE: shutdown must come first.
90 * Shutdown the device.
92 if (ud->event & USBIP_EH_SHUTDOWN) {
93 ud->eh_ops.shutdown(ud);
94 unset_event(ud, USBIP_EH_SHUTDOWN);
97 /* Reset the device. */
98 if (ud->event & USBIP_EH_RESET) {
100 unset_event(ud, USBIP_EH_RESET);
103 /* Mark the device as unusable. */
104 if (ud->event & USBIP_EH_UNUSABLE) {
105 ud->eh_ops.unusable(ud);
106 unset_event(ud, USBIP_EH_UNUSABLE);
108 mutex_unlock(&ud->sysfs_lock);
110 wake_up(&ud->eh_waitq);
114 int usbip_start_eh(struct usbip_device *ud)
116 init_waitqueue_head(&ud->eh_waitq);
120 EXPORT_SYMBOL_GPL(usbip_start_eh);
122 void usbip_stop_eh(struct usbip_device *ud)
124 unsigned long pending = ud->event & ~USBIP_EH_BYE;
126 if (!(ud->event & USBIP_EH_BYE))
127 usbip_dbg_eh("usbip_eh stopping but not removed\n");
130 usbip_dbg_eh("usbip_eh waiting completion %lx\n", pending);
132 wait_event_interruptible(ud->eh_waitq, !(ud->event & ~USBIP_EH_BYE));
133 usbip_dbg_eh("usbip_eh has stopped\n");
135 EXPORT_SYMBOL_GPL(usbip_stop_eh);
137 #define WORK_QUEUE_NAME "usbip_event"
139 static struct workqueue_struct *usbip_queue;
140 static DECLARE_WORK(usbip_work, event_handler);
142 int usbip_init_eh(void)
144 usbip_queue = create_singlethread_workqueue(WORK_QUEUE_NAME);
145 if (usbip_queue == NULL) {
146 pr_err("failed to create usbip_event\n");
152 void usbip_finish_eh(void)
154 flush_workqueue(usbip_queue);
155 destroy_workqueue(usbip_queue);
159 void usbip_event_add(struct usbip_device *ud, unsigned long event)
161 struct usbip_event *ue;
164 if (ud->event & USBIP_EH_BYE)
167 set_event(ud, event);
169 spin_lock_irqsave(&event_lock, flags);
171 list_for_each_entry_reverse(ue, &event_list, node) {
176 ue = kmalloc(sizeof(struct usbip_event), GFP_ATOMIC);
182 list_add_tail(&ue->node, &event_list);
183 queue_work(usbip_queue, &usbip_work);
186 spin_unlock_irqrestore(&event_lock, flags);
188 EXPORT_SYMBOL_GPL(usbip_event_add);
190 int usbip_event_happened(struct usbip_device *ud)
195 spin_lock_irqsave(&ud->lock, flags);
198 spin_unlock_irqrestore(&ud->lock, flags);
202 EXPORT_SYMBOL_GPL(usbip_event_happened);
204 int usbip_in_eh(struct task_struct *task)
206 if (task == worker_context)
211 EXPORT_SYMBOL_GPL(usbip_in_eh);