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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/staging/usbip/
1/*
2 * Copyright (C) 2003-2008 Takahiro Hirofuchi
3 *
4 * This is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
17 * USA.
18 */
19
20#include <linux/slab.h>
21
22#include "usbip_common.h"
23#include "stub.h"
24
25
26static void stub_free_priv_and_urb(struct stub_priv *priv)
27{
28	struct urb *urb = priv->urb;
29
30	kfree(urb->setup_packet);
31	kfree(urb->transfer_buffer);
32	list_del(&priv->list);
33	kmem_cache_free(stub_priv_cache, priv);
34	usb_free_urb(urb);
35}
36
37/* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
38void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
39			     __u32 status)
40{
41	struct stub_unlink *unlink;
42
43	unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
44	if (!unlink) {
45		dev_err(&sdev->interface->dev, "alloc stub_unlink\n");
46		usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
47		return;
48	}
49
50	unlink->seqnum = seqnum;
51	unlink->status = status;
52
53	list_add_tail(&unlink->list, &sdev->unlink_tx);
54}
55
56/**
57 * stub_complete - completion handler of a usbip urb
58 * @urb: pointer to the urb completed
59 *
60 * When a urb has completed, the USB core driver calls this function mostly in
61 * the interrupt context. To return the result of a urb, the completed urb is
62 * linked to the pending list of returning.
63 *
64 */
65void stub_complete(struct urb *urb)
66{
67	struct stub_priv *priv = (struct stub_priv *) urb->context;
68	struct stub_device *sdev = priv->sdev;
69	unsigned long flags;
70
71	usbip_dbg_stub_tx("complete! status %d\n", urb->status);
72
73
74	switch (urb->status) {
75	case 0:
76		/* OK */
77		break;
78	case -ENOENT:
79		usbip_uinfo("stopped by a call of usb_kill_urb() because of"
80					"cleaning up a virtual connection\n");
81		return;
82	case -ECONNRESET:
83		usbip_uinfo("unlinked by a call of usb_unlink_urb()\n");
84		break;
85	case -EPIPE:
86		usbip_uinfo("endpoint %d is stalled\n",
87						usb_pipeendpoint(urb->pipe));
88		break;
89	case -ESHUTDOWN:
90		usbip_uinfo("device removed?\n");
91		break;
92	default:
93		usbip_uinfo("urb completion with non-zero status %d\n",
94							urb->status);
95	}
96
97	/* link a urb to the queue of tx. */
98	spin_lock_irqsave(&sdev->priv_lock, flags);
99
100	if (priv->unlinking) {
101		stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
102		stub_free_priv_and_urb(priv);
103	} else
104		list_move_tail(&priv->list, &sdev->priv_tx);
105
106
107	spin_unlock_irqrestore(&sdev->priv_lock, flags);
108
109	/* wake up tx_thread */
110	wake_up(&sdev->tx_waitq);
111}
112
113
114/*-------------------------------------------------------------------------*/
115/* fill PDU */
116
117static inline void setup_base_pdu(struct usbip_header_basic *base,
118		__u32 command, __u32 seqnum)
119{
120	base->command = command;
121	base->seqnum  = seqnum;
122	base->devid   = 0;
123	base->ep      = 0;
124	base->direction   = 0;
125}
126
127static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
128{
129	struct stub_priv *priv = (struct stub_priv *) urb->context;
130
131	setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
132
133	usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
134}
135
136static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
137		struct stub_unlink *unlink)
138{
139	setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
140
141	rpdu->u.ret_unlink.status = unlink->status;
142}
143
144
145/*-------------------------------------------------------------------------*/
146/* send RET_SUBMIT */
147
148static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
149{
150	unsigned long flags;
151	struct stub_priv *priv, *tmp;
152
153	spin_lock_irqsave(&sdev->priv_lock, flags);
154
155	list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
156		list_move_tail(&priv->list, &sdev->priv_free);
157		spin_unlock_irqrestore(&sdev->priv_lock, flags);
158		return priv;
159	}
160
161	spin_unlock_irqrestore(&sdev->priv_lock, flags);
162
163	return NULL;
164}
165
166static int stub_send_ret_submit(struct stub_device *sdev)
167{
168	unsigned long flags;
169	struct stub_priv *priv, *tmp;
170
171	struct msghdr msg;
172	struct kvec iov[3];
173	size_t txsize;
174
175	size_t total_size = 0;
176
177	while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
178		int ret;
179		struct urb *urb = priv->urb;
180		struct usbip_header pdu_header;
181		void *iso_buffer = NULL;
182
183		txsize = 0;
184		memset(&pdu_header, 0, sizeof(pdu_header));
185		memset(&msg, 0, sizeof(msg));
186		memset(&iov, 0, sizeof(iov));
187
188		usbip_dbg_stub_tx("setup txdata urb %p\n", urb);
189
190
191		/* 1. setup usbip_header */
192		setup_ret_submit_pdu(&pdu_header, urb);
193		usbip_header_correct_endian(&pdu_header, 1);
194
195		iov[0].iov_base = &pdu_header;
196		iov[0].iov_len  = sizeof(pdu_header);
197		txsize += sizeof(pdu_header);
198
199		/* 2. setup transfer buffer */
200		if (usb_pipein(urb->pipe) && urb->actual_length > 0) {
201			iov[1].iov_base = urb->transfer_buffer;
202			iov[1].iov_len  = urb->actual_length;
203			txsize += urb->actual_length;
204		}
205
206		/* 3. setup iso_packet_descriptor */
207		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
208			ssize_t len = 0;
209
210			iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
211			if (!iso_buffer) {
212				usbip_event_add(&sdev->ud,
213						SDEV_EVENT_ERROR_MALLOC);
214				return -1;
215			}
216
217			iov[2].iov_base = iso_buffer;
218			iov[2].iov_len  = len;
219			txsize += len;
220		}
221
222		ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
223				     3, txsize);
224		if (ret != txsize) {
225			dev_err(&sdev->interface->dev,
226				"sendmsg failed!, retval %d for %zd\n",
227				ret, txsize);
228			kfree(iso_buffer);
229			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
230			return -1;
231		}
232
233		kfree(iso_buffer);
234		usbip_dbg_stub_tx("send txdata\n");
235
236		total_size += txsize;
237	}
238
239
240	spin_lock_irqsave(&sdev->priv_lock, flags);
241
242	list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
243		stub_free_priv_and_urb(priv);
244	}
245
246	spin_unlock_irqrestore(&sdev->priv_lock, flags);
247
248	return total_size;
249}
250
251
252/*-------------------------------------------------------------------------*/
253/* send RET_UNLINK */
254
255static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
256{
257	unsigned long flags;
258	struct stub_unlink *unlink, *tmp;
259
260	spin_lock_irqsave(&sdev->priv_lock, flags);
261
262	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
263		list_move_tail(&unlink->list, &sdev->unlink_free);
264		spin_unlock_irqrestore(&sdev->priv_lock, flags);
265		return unlink;
266	}
267
268	spin_unlock_irqrestore(&sdev->priv_lock, flags);
269
270	return NULL;
271}
272
273
274static int stub_send_ret_unlink(struct stub_device *sdev)
275{
276	unsigned long flags;
277	struct stub_unlink *unlink, *tmp;
278
279	struct msghdr msg;
280	struct kvec iov[1];
281	size_t txsize;
282
283	size_t total_size = 0;
284
285	while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
286		int ret;
287		struct usbip_header pdu_header;
288
289		txsize = 0;
290		memset(&pdu_header, 0, sizeof(pdu_header));
291		memset(&msg, 0, sizeof(msg));
292		memset(&iov, 0, sizeof(iov));
293
294		usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
295
296		/* 1. setup usbip_header */
297		setup_ret_unlink_pdu(&pdu_header, unlink);
298		usbip_header_correct_endian(&pdu_header, 1);
299
300		iov[0].iov_base = &pdu_header;
301		iov[0].iov_len  = sizeof(pdu_header);
302		txsize += sizeof(pdu_header);
303
304		ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
305				     1, txsize);
306		if (ret != txsize) {
307			dev_err(&sdev->interface->dev,
308				"sendmsg failed!, retval %d for %zd\n",
309				ret, txsize);
310			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
311			return -1;
312		}
313
314
315		usbip_dbg_stub_tx("send txdata\n");
316
317		total_size += txsize;
318	}
319
320
321	spin_lock_irqsave(&sdev->priv_lock, flags);
322
323	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
324		list_del(&unlink->list);
325		kfree(unlink);
326	}
327
328	spin_unlock_irqrestore(&sdev->priv_lock, flags);
329
330	return total_size;
331}
332
333
334/*-------------------------------------------------------------------------*/
335
336void stub_tx_loop(struct usbip_task *ut)
337{
338	struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
339	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
340
341	while (1) {
342		if (signal_pending(current)) {
343			usbip_dbg_stub_tx("signal catched\n");
344			break;
345		}
346
347		if (usbip_event_happened(ud))
348			break;
349
350		/*
351		 * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
352		 * looks at only priv_init queue. If the completion of a URB is
353		 * earlier than the receive of CMD_UNLINK, priv is moved to
354		 * priv_tx queue and stub_rx does not find the target priv. In
355		 * this case, vhci_rx receives the result of the submit request
356		 * and then receives the result of the unlink request. The
357		 * result of the submit is given back to the usbcore as the
358		 * completion of the unlink request. The request of the
359		 * unlink is ignored. This is ok because a driver who calls
360		 * usb_unlink_urb() understands the unlink was too late by
361		 * getting the status of the given-backed URB which has the
362		 * status of usb_submit_urb().
363		 */
364		if (stub_send_ret_submit(sdev) < 0)
365			break;
366
367		if (stub_send_ret_unlink(sdev) < 0)
368			break;
369
370		wait_event_interruptible(sdev->tx_waitq,
371				(!list_empty(&sdev->priv_tx) ||
372				 !list_empty(&sdev->unlink_tx)));
373	}
374}
375