Commit | Line | Data |
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05a1f28e TH |
1 | /* |
2 | * Copyright (C) 2003-2008 Takahiro Hirofuchi | |
bb7871ad | 3 | * Copyright (C) 2015 Nobuo Iwata |
05a1f28e TH |
4 | * |
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. | |
9 | * | |
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. | |
14 | * | |
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, | |
18 | * USA. | |
19 | */ | |
20 | ||
b8868e45 | 21 | #include <linux/kthread.h> |
8e336a72 | 22 | #include <linux/export.h> |
bb7871ad NI |
23 | #include <linux/slab.h> |
24 | #include <linux/workqueue.h> | |
7aaacb43 | 25 | |
0f79847c | 26 | #include "usbip_common.h" |
05a1f28e | 27 | |
bb7871ad NI |
28 | struct usbip_event { |
29 | struct list_head node; | |
30 | struct usbip_device *ud; | |
31 | }; | |
32 | ||
33 | static DEFINE_SPINLOCK(event_lock); | |
34 | static LIST_HEAD(event_list); | |
35 | ||
36 | static void set_event(struct usbip_device *ud, unsigned long event) | |
05a1f28e | 37 | { |
bb7871ad | 38 | unsigned long flags; |
05a1f28e | 39 | |
bb7871ad NI |
40 | spin_lock_irqsave(&ud->lock, flags); |
41 | ud->event |= event; | |
42 | spin_unlock_irqrestore(&ud->lock, flags); | |
43 | } | |
44 | ||
45 | static void unset_event(struct usbip_device *ud, unsigned long event) | |
46 | { | |
47 | unsigned long flags; | |
48 | ||
49 | spin_lock_irqsave(&ud->lock, flags); | |
50 | ud->event &= ~event; | |
51 | spin_unlock_irqrestore(&ud->lock, flags); | |
52 | } | |
53 | ||
54 | static struct usbip_device *get_event(void) | |
55 | { | |
56 | struct usbip_event *ue = NULL; | |
57 | struct usbip_device *ud = NULL; | |
58 | unsigned long flags; | |
59 | ||
60 | spin_lock_irqsave(&event_lock, flags); | |
61 | if (!list_empty(&event_list)) { | |
62 | ue = list_first_entry(&event_list, struct usbip_event, node); | |
63 | list_del(&ue->node); | |
64 | } | |
65 | spin_unlock_irqrestore(&event_lock, flags); | |
66 | ||
67 | if (ue) { | |
68 | ud = ue->ud; | |
69 | kfree(ue); | |
70 | } | |
71 | return ud; | |
72 | } | |
73 | ||
74 | static struct task_struct *worker_context; | |
75 | ||
76 | static void event_handler(struct work_struct *work) | |
77 | { | |
78 | struct usbip_device *ud; | |
79 | ||
80 | if (worker_context == NULL) { | |
81 | worker_context = current; | |
82 | } | |
83 | ||
84 | while ((ud = get_event()) != NULL) { | |
b8868e45 | 85 | usbip_dbg_eh("pending event %lx\n", ud->event); |
05a1f28e TH |
86 | |
87 | /* | |
88 | * NOTE: shutdown must come first. | |
89 | * Shutdown the device. | |
90 | */ | |
91 | if (ud->event & USBIP_EH_SHUTDOWN) { | |
92 | ud->eh_ops.shutdown(ud); | |
bb7871ad | 93 | unset_event(ud, USBIP_EH_SHUTDOWN); |
05a1f28e TH |
94 | } |
95 | ||
05a1f28e TH |
96 | /* Reset the device. */ |
97 | if (ud->event & USBIP_EH_RESET) { | |
98 | ud->eh_ops.reset(ud); | |
bb7871ad | 99 | unset_event(ud, USBIP_EH_RESET); |
05a1f28e TH |
100 | } |
101 | ||
102 | /* Mark the device as unusable. */ | |
103 | if (ud->event & USBIP_EH_UNUSABLE) { | |
104 | ud->eh_ops.unusable(ud); | |
bb7871ad | 105 | unset_event(ud, USBIP_EH_UNUSABLE); |
05a1f28e TH |
106 | } |
107 | ||
584c5b7c MV |
108 | /* Stop the error handler. */ |
109 | if (ud->event & USBIP_EH_BYE) | |
bb7871ad NI |
110 | usbip_dbg_eh("removed %p\n", ud); |
111 | ||
112 | wake_up(&ud->eh_waitq); | |
05a1f28e | 113 | } |
bb7871ad | 114 | } |
05a1f28e | 115 | |
bb7871ad NI |
116 | int usbip_start_eh(struct usbip_device *ud) |
117 | { | |
118 | init_waitqueue_head(&ud->eh_waitq); | |
119 | ud->event = 0; | |
05a1f28e TH |
120 | return 0; |
121 | } | |
bb7871ad | 122 | EXPORT_SYMBOL_GPL(usbip_start_eh); |
05a1f28e | 123 | |
bb7871ad | 124 | void usbip_stop_eh(struct usbip_device *ud) |
05a1f28e | 125 | { |
bb7871ad | 126 | unsigned long pending = ud->event & ~USBIP_EH_BYE; |
05a1f28e | 127 | |
bb7871ad NI |
128 | if (!(ud->event & USBIP_EH_BYE)) |
129 | usbip_dbg_eh("usbip_eh stopping but not removed\n"); | |
05a1f28e | 130 | |
bb7871ad NI |
131 | if (pending) |
132 | usbip_dbg_eh("usbip_eh waiting completion %lx\n", pending); | |
0f79847c | 133 | |
bb7871ad NI |
134 | wait_event_interruptible(ud->eh_waitq, !(ud->event & ~USBIP_EH_BYE)); |
135 | usbip_dbg_eh("usbip_eh has stopped\n"); | |
05a1f28e | 136 | } |
bb7871ad | 137 | EXPORT_SYMBOL_GPL(usbip_stop_eh); |
05a1f28e | 138 | |
bb7871ad | 139 | #define WORK_QUEUE_NAME "usbip_event" |
05a1f28e | 140 | |
bb7871ad NI |
141 | static struct workqueue_struct *usbip_queue; |
142 | static DECLARE_WORK(usbip_work, event_handler); | |
0f79847c | 143 | |
bb7871ad NI |
144 | int usbip_init_eh(void) |
145 | { | |
146 | usbip_queue = create_singlethread_workqueue(WORK_QUEUE_NAME); | |
147 | if (usbip_queue == NULL) { | |
148 | pr_err("failed to create usbip_event\n"); | |
149 | return -ENOMEM; | |
150 | } | |
b8868e45 | 151 | return 0; |
05a1f28e | 152 | } |
05a1f28e | 153 | |
bb7871ad | 154 | void usbip_finish_eh(void) |
05a1f28e | 155 | { |
bb7871ad NI |
156 | flush_workqueue(usbip_queue); |
157 | destroy_workqueue(usbip_queue); | |
158 | usbip_queue = NULL; | |
05a1f28e | 159 | } |
05a1f28e TH |
160 | |
161 | void usbip_event_add(struct usbip_device *ud, unsigned long event) | |
162 | { | |
bb7871ad | 163 | struct usbip_event *ue; |
dcf14779 HY |
164 | unsigned long flags; |
165 | ||
bb7871ad NI |
166 | if (ud->event & USBIP_EH_BYE) |
167 | return; | |
168 | ||
169 | set_event(ud, event); | |
170 | ||
171 | spin_lock_irqsave(&event_lock, flags); | |
172 | ||
173 | list_for_each_entry_reverse(ue, &event_list, node) { | |
174 | if (ue->ud == ud) | |
175 | goto out; | |
176 | } | |
177 | ||
178 | ue = kmalloc(sizeof(struct usbip_event), GFP_ATOMIC); | |
179 | if (ue == NULL) | |
180 | goto out; | |
181 | ||
182 | ue->ud = ud; | |
183 | ||
184 | list_add_tail(&ue->node, &event_list); | |
185 | queue_work(usbip_queue, &usbip_work); | |
186 | ||
187 | out: | |
188 | spin_unlock_irqrestore(&event_lock, flags); | |
05a1f28e TH |
189 | } |
190 | EXPORT_SYMBOL_GPL(usbip_event_add); | |
191 | ||
b8868e45 | 192 | int usbip_event_happened(struct usbip_device *ud) |
05a1f28e | 193 | { |
b8868e45 | 194 | int happened = 0; |
21619792 | 195 | unsigned long flags; |
05a1f28e | 196 | |
21619792 | 197 | spin_lock_irqsave(&ud->lock, flags); |
05a1f28e | 198 | if (ud->event != 0) |
b8868e45 | 199 | happened = 1; |
21619792 | 200 | spin_unlock_irqrestore(&ud->lock, flags); |
05a1f28e | 201 | |
b8868e45 | 202 | return happened; |
05a1f28e | 203 | } |
b8868e45 | 204 | EXPORT_SYMBOL_GPL(usbip_event_happened); |
bb7871ad NI |
205 | |
206 | int usbip_in_eh(struct task_struct *task) | |
207 | { | |
208 | if (task == worker_context) | |
209 | return 1; | |
210 | ||
211 | return 0; | |
212 | } | |
213 | EXPORT_SYMBOL_GPL(usbip_in_eh); |