xref: /openbmc/linux/drivers/usb/usbip/vhci_hcd.c (revision 020c5260)
1 /*
2  * Copyright (C) 2003-2008 Takahiro Hirofuchi
3  * Copyright (C) 2015-2016 Nobuo Iwata
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 
21 #include <linux/init.h>
22 #include <linux/file.h>
23 #include <linux/kernel.h>
24 #include <linux/kthread.h>
25 #include <linux/module.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 
29 #include "usbip_common.h"
30 #include "vhci.h"
31 
32 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
33 #define DRIVER_DESC "USB/IP 'Virtual' Host Controller (VHCI) Driver"
34 
35 /*
36  * TODO
37  *	- update root hub emulation
38  *	- move the emulation code to userland ?
39  *		porting to other operating systems
40  *		minimize kernel code
41  *	- add suspend/resume code
42  *	- clean up everything
43  */
44 
45 /* See usb gadget dummy hcd */
46 
47 static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
48 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
49 			    u16 wIndex, char *buff, u16 wLength);
50 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
51 			    gfp_t mem_flags);
52 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
53 static int vhci_start(struct usb_hcd *vhci_hcd);
54 static void vhci_stop(struct usb_hcd *hcd);
55 static int vhci_get_frame_number(struct usb_hcd *hcd);
56 
57 static const char driver_name[] = "vhci_hcd";
58 static const char driver_desc[] = "USB/IP Virtual Host Controller";
59 
60 int vhci_num_controllers = VHCI_NR_HCS;
61 
62 struct platform_device **vhci_pdevs;
63 
64 static const char * const bit_desc[] = {
65 	"CONNECTION",		/*0*/
66 	"ENABLE",		/*1*/
67 	"SUSPEND",		/*2*/
68 	"OVER_CURRENT",		/*3*/
69 	"RESET",		/*4*/
70 	"R5",			/*5*/
71 	"R6",			/*6*/
72 	"R7",			/*7*/
73 	"POWER",		/*8*/
74 	"LOWSPEED",		/*9*/
75 	"HIGHSPEED",		/*10*/
76 	"PORT_TEST",		/*11*/
77 	"INDICATOR",		/*12*/
78 	"R13",			/*13*/
79 	"R14",			/*14*/
80 	"R15",			/*15*/
81 	"C_CONNECTION",		/*16*/
82 	"C_ENABLE",		/*17*/
83 	"C_SUSPEND",		/*18*/
84 	"C_OVER_CURRENT",	/*19*/
85 	"C_RESET",		/*20*/
86 	"R21",			/*21*/
87 	"R22",			/*22*/
88 	"R23",			/*23*/
89 	"R24",			/*24*/
90 	"R25",			/*25*/
91 	"R26",			/*26*/
92 	"R27",			/*27*/
93 	"R28",			/*28*/
94 	"R29",			/*29*/
95 	"R30",			/*30*/
96 	"R31",			/*31*/
97 };
98 
99 static void dump_port_status_diff(u32 prev_status, u32 new_status)
100 {
101 	int i = 0;
102 	u32 bit = 1;
103 
104 	pr_debug("status prev -> new: %08x -> %08x\n", prev_status, new_status);
105 	while (bit) {
106 		u32 prev = prev_status & bit;
107 		u32 new = new_status & bit;
108 		char change;
109 
110 		if (!prev && new)
111 			change = '+';
112 		else if (prev && !new)
113 			change = '-';
114 		else
115 			change = ' ';
116 
117 		if (prev || new)
118 			pr_debug(" %c%s\n", change, bit_desc[i]);
119 		bit <<= 1;
120 		i++;
121 	}
122 	pr_debug("\n");
123 }
124 
125 void rh_port_connect(struct vhci_device *vdev, enum usb_device_speed speed)
126 {
127 	struct vhci_hcd	*vhci = vdev_to_vhci(vdev);
128 	int		rhport = vdev->rhport;
129 	u32		status;
130 	unsigned long	flags;
131 
132 	usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
133 
134 	spin_lock_irqsave(&vhci->lock, flags);
135 
136 	status = vhci->port_status[rhport];
137 
138 	status |= USB_PORT_STAT_CONNECTION | (1 << USB_PORT_FEAT_C_CONNECTION);
139 
140 	switch (speed) {
141 	case USB_SPEED_HIGH:
142 		status |= USB_PORT_STAT_HIGH_SPEED;
143 		break;
144 	case USB_SPEED_LOW:
145 		status |= USB_PORT_STAT_LOW_SPEED;
146 		break;
147 	default:
148 		break;
149 	}
150 
151 	vhci->port_status[rhport] = status;
152 
153 	spin_unlock_irqrestore(&vhci->lock, flags);
154 
155 	usb_hcd_poll_rh_status(vhci_to_hcd(vhci));
156 }
157 
158 static void rh_port_disconnect(struct vhci_device *vdev)
159 {
160 	struct vhci_hcd	*vhci = vdev_to_vhci(vdev);
161 	int		rhport = vdev->rhport;
162 	u32		status;
163 	unsigned long	flags;
164 
165 	usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
166 
167 	spin_lock_irqsave(&vhci->lock, flags);
168 
169 	status = vhci->port_status[rhport];
170 
171 	status &= ~USB_PORT_STAT_CONNECTION;
172 	status |= (1 << USB_PORT_FEAT_C_CONNECTION);
173 
174 	vhci->port_status[rhport] = status;
175 
176 	spin_unlock_irqrestore(&vhci->lock, flags);
177 	usb_hcd_poll_rh_status(vhci_to_hcd(vhci));
178 }
179 
180 #define PORT_C_MASK				\
181 	((USB_PORT_STAT_C_CONNECTION		\
182 	  | USB_PORT_STAT_C_ENABLE		\
183 	  | USB_PORT_STAT_C_SUSPEND		\
184 	  | USB_PORT_STAT_C_OVERCURRENT		\
185 	  | USB_PORT_STAT_C_RESET) << 16)
186 
187 /*
188  * Returns 0 if the status hasn't changed, or the number of bytes in buf.
189  * Ports are 0-indexed from the HCD point of view,
190  * and 1-indexed from the USB core pointer of view.
191  *
192  * @buf: a bitmap to show which port status has been changed.
193  *  bit  0: reserved
194  *  bit  1: the status of port 0 has been changed.
195  *  bit  2: the status of port 1 has been changed.
196  *  ...
197  */
198 static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
199 {
200 	struct vhci_hcd	*vhci;
201 	int		retval;
202 	int		rhport;
203 	int		changed = 0;
204 	unsigned long	flags;
205 
206 	retval = DIV_ROUND_UP(VHCI_HC_PORTS + 1, 8);
207 	memset(buf, 0, retval);
208 
209 	vhci = hcd_to_vhci(hcd);
210 
211 	spin_lock_irqsave(&vhci->lock, flags);
212 	if (!HCD_HW_ACCESSIBLE(hcd)) {
213 		usbip_dbg_vhci_rh("hw accessible flag not on?\n");
214 		goto done;
215 	}
216 
217 	/* check pseudo status register for each port */
218 	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
219 		if ((vhci->port_status[rhport] & PORT_C_MASK)) {
220 			/* The status of a port has been changed, */
221 			usbip_dbg_vhci_rh("port %d status changed\n", rhport);
222 
223 			buf[(rhport + 1) / 8] |= 1 << (rhport + 1) % 8;
224 			changed = 1;
225 		}
226 	}
227 
228 	if ((hcd->state == HC_STATE_SUSPENDED) && (changed == 1))
229 		usb_hcd_resume_root_hub(hcd);
230 
231 done:
232 	spin_unlock_irqrestore(&vhci->lock, flags);
233 	return changed ? retval : 0;
234 }
235 
236 static inline void hub_descriptor(struct usb_hub_descriptor *desc)
237 {
238 	memset(desc, 0, sizeof(*desc));
239 	desc->bDescriptorType = USB_DT_HUB;
240 	desc->bDescLength = 9;
241 	desc->wHubCharacteristics = cpu_to_le16(
242 		HUB_CHAR_INDV_PORT_LPSM | HUB_CHAR_COMMON_OCPM);
243 	desc->bNbrPorts = VHCI_HC_PORTS;
244 	desc->u.hs.DeviceRemovable[0] = 0xff;
245 	desc->u.hs.DeviceRemovable[1] = 0xff;
246 }
247 
248 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
249 			    u16 wIndex, char *buf, u16 wLength)
250 {
251 	struct vhci_hcd	*dum;
252 	int             retval = 0;
253 	int		rhport;
254 	unsigned long	flags;
255 
256 	u32 prev_port_status[VHCI_HC_PORTS];
257 
258 	if (!HCD_HW_ACCESSIBLE(hcd))
259 		return -ETIMEDOUT;
260 
261 	/*
262 	 * NOTE:
263 	 * wIndex shows the port number and begins from 1.
264 	 */
265 	usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
266 			  wIndex);
267 	if (wIndex > VHCI_HC_PORTS)
268 		pr_err("invalid port number %d\n", wIndex);
269 	rhport = ((__u8)(wIndex & 0x00ff)) - 1;
270 
271 	dum = hcd_to_vhci(hcd);
272 
273 	spin_lock_irqsave(&dum->lock, flags);
274 
275 	/* store old status and compare now and old later */
276 	if (usbip_dbg_flag_vhci_rh) {
277 		memcpy(prev_port_status, dum->port_status,
278 			sizeof(prev_port_status));
279 	}
280 
281 	switch (typeReq) {
282 	case ClearHubFeature:
283 		usbip_dbg_vhci_rh(" ClearHubFeature\n");
284 		break;
285 	case ClearPortFeature:
286 		switch (wValue) {
287 		case USB_PORT_FEAT_SUSPEND:
288 			if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
289 				/* 20msec signaling */
290 				dum->resuming = 1;
291 				dum->re_timeout =
292 					jiffies + msecs_to_jiffies(20);
293 			}
294 			break;
295 		case USB_PORT_FEAT_POWER:
296 			usbip_dbg_vhci_rh(
297 				" ClearPortFeature: USB_PORT_FEAT_POWER\n");
298 			dum->port_status[rhport] = 0;
299 			dum->resuming = 0;
300 			break;
301 		case USB_PORT_FEAT_C_RESET:
302 			usbip_dbg_vhci_rh(
303 				" ClearPortFeature: USB_PORT_FEAT_C_RESET\n");
304 			switch (dum->vdev[rhport].speed) {
305 			case USB_SPEED_HIGH:
306 				dum->port_status[rhport] |=
307 					USB_PORT_STAT_HIGH_SPEED;
308 				break;
309 			case USB_SPEED_LOW:
310 				dum->port_status[rhport] |=
311 					USB_PORT_STAT_LOW_SPEED;
312 				break;
313 			default:
314 				break;
315 			}
316 			break;
317 		default:
318 			usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
319 					  wValue);
320 			dum->port_status[rhport] &= ~(1 << wValue);
321 			break;
322 		}
323 		break;
324 	case GetHubDescriptor:
325 		usbip_dbg_vhci_rh(" GetHubDescriptor\n");
326 		hub_descriptor((struct usb_hub_descriptor *) buf);
327 		break;
328 	case GetHubStatus:
329 		usbip_dbg_vhci_rh(" GetHubStatus\n");
330 		*(__le32 *) buf = cpu_to_le32(0);
331 		break;
332 	case GetPortStatus:
333 		usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
334 		if (wIndex > VHCI_HC_PORTS || wIndex < 1) {
335 			pr_err("invalid port number %d\n", wIndex);
336 			retval = -EPIPE;
337 		}
338 
339 		/* we do not care about resume. */
340 
341 		/* whoever resets or resumes must GetPortStatus to
342 		 * complete it!!
343 		 */
344 		if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
345 			dum->port_status[rhport] |=
346 				(1 << USB_PORT_FEAT_C_SUSPEND);
347 			dum->port_status[rhport] &=
348 				~(1 << USB_PORT_FEAT_SUSPEND);
349 			dum->resuming = 0;
350 			dum->re_timeout = 0;
351 		}
352 
353 		if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
354 		    0 && time_after(jiffies, dum->re_timeout)) {
355 			dum->port_status[rhport] |=
356 				(1 << USB_PORT_FEAT_C_RESET);
357 			dum->port_status[rhport] &=
358 				~(1 << USB_PORT_FEAT_RESET);
359 			dum->re_timeout = 0;
360 
361 			if (dum->vdev[rhport].ud.status ==
362 			    VDEV_ST_NOTASSIGNED) {
363 				usbip_dbg_vhci_rh(
364 					" enable rhport %d (status %u)\n",
365 					rhport,
366 					dum->vdev[rhport].ud.status);
367 				dum->port_status[rhport] |=
368 					USB_PORT_STAT_ENABLE;
369 			}
370 		}
371 		((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
372 		((__le16 *) buf)[1] =
373 			cpu_to_le16(dum->port_status[rhport] >> 16);
374 
375 		usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
376 				  ((u16 *)buf)[1]);
377 		break;
378 	case SetHubFeature:
379 		usbip_dbg_vhci_rh(" SetHubFeature\n");
380 		retval = -EPIPE;
381 		break;
382 	case SetPortFeature:
383 		switch (wValue) {
384 		case USB_PORT_FEAT_SUSPEND:
385 			usbip_dbg_vhci_rh(
386 				" SetPortFeature: USB_PORT_FEAT_SUSPEND\n");
387 			break;
388 		case USB_PORT_FEAT_RESET:
389 			usbip_dbg_vhci_rh(
390 				" SetPortFeature: USB_PORT_FEAT_RESET\n");
391 			/* if it's already running, disconnect first */
392 			if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
393 				dum->port_status[rhport] &=
394 					~(USB_PORT_STAT_ENABLE |
395 					  USB_PORT_STAT_LOW_SPEED |
396 					  USB_PORT_STAT_HIGH_SPEED);
397 				/* FIXME test that code path! */
398 			}
399 			/* 50msec reset signaling */
400 			dum->re_timeout = jiffies + msecs_to_jiffies(50);
401 
402 			/* FALLTHROUGH */
403 		default:
404 			usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
405 					  wValue);
406 			dum->port_status[rhport] |= (1 << wValue);
407 			break;
408 		}
409 		break;
410 
411 	default:
412 		pr_err("default: no such request\n");
413 
414 		/* "protocol stall" on error */
415 		retval = -EPIPE;
416 	}
417 
418 	if (usbip_dbg_flag_vhci_rh) {
419 		pr_debug("port %d\n", rhport);
420 		/* Only dump valid port status */
421 		if (rhport >= 0) {
422 			dump_port_status_diff(prev_port_status[rhport],
423 					      dum->port_status[rhport]);
424 		}
425 	}
426 	usbip_dbg_vhci_rh(" bye\n");
427 
428 	spin_unlock_irqrestore(&dum->lock, flags);
429 
430 	return retval;
431 }
432 
433 static void vhci_tx_urb(struct urb *urb, struct vhci_device *vdev)
434 {
435 	struct vhci_priv *priv;
436 	struct vhci_hcd *vhci;
437 	unsigned long flags;
438 
439 	if (!vdev) {
440 		pr_err("could not get virtual device");
441 		return;
442 	}
443 	vhci = vdev_to_vhci(vdev);
444 
445 	priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
446 	if (!priv) {
447 		usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
448 		return;
449 	}
450 
451 	spin_lock_irqsave(&vdev->priv_lock, flags);
452 
453 	priv->seqnum = atomic_inc_return(&vhci->seqnum);
454 	if (priv->seqnum == 0xffff)
455 		dev_info(&urb->dev->dev, "seqnum max\n");
456 
457 	priv->vdev = vdev;
458 	priv->urb = urb;
459 
460 	urb->hcpriv = (void *) priv;
461 
462 	list_add_tail(&priv->list, &vdev->priv_tx);
463 
464 	wake_up(&vdev->waitq_tx);
465 	spin_unlock_irqrestore(&vdev->priv_lock, flags);
466 }
467 
468 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
469 			    gfp_t mem_flags)
470 {
471 	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
472 	struct device *dev = &urb->dev->dev;
473 	u8 portnum = urb->dev->portnum;
474 	int ret = 0;
475 	struct vhci_device *vdev;
476 	unsigned long flags;
477 
478 	usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
479 			  hcd, urb, mem_flags);
480 
481 	if (portnum > VHCI_HC_PORTS) {
482 		pr_err("invalid port number %d\n", portnum);
483 		return -ENODEV;
484 	}
485 	vdev = &vhci->vdev[portnum-1];
486 
487 	/* patch to usb_sg_init() is in 2.5.60 */
488 	BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
489 
490 	spin_lock_irqsave(&vhci->lock, flags);
491 
492 	if (urb->status != -EINPROGRESS) {
493 		dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
494 		spin_unlock_irqrestore(&vhci->lock, flags);
495 		return urb->status;
496 	}
497 
498 	/* refuse enqueue for dead connection */
499 	spin_lock(&vdev->ud.lock);
500 	if (vdev->ud.status == VDEV_ST_NULL ||
501 	    vdev->ud.status == VDEV_ST_ERROR) {
502 		dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
503 		spin_unlock(&vdev->ud.lock);
504 		spin_unlock_irqrestore(&vhci->lock, flags);
505 		return -ENODEV;
506 	}
507 	spin_unlock(&vdev->ud.lock);
508 
509 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
510 	if (ret)
511 		goto no_need_unlink;
512 
513 	/*
514 	 * The enumeration process is as follows;
515 	 *
516 	 *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
517 	 *     to get max packet length of default pipe
518 	 *
519 	 *  2. Set_Address request to DevAddr(0) EndPoint(0)
520 	 *
521 	 */
522 	if (usb_pipedevice(urb->pipe) == 0) {
523 		__u8 type = usb_pipetype(urb->pipe);
524 		struct usb_ctrlrequest *ctrlreq =
525 			(struct usb_ctrlrequest *) urb->setup_packet;
526 
527 		if (type != PIPE_CONTROL || !ctrlreq) {
528 			dev_err(dev, "invalid request to devnum 0\n");
529 			ret = -EINVAL;
530 			goto no_need_xmit;
531 		}
532 
533 		switch (ctrlreq->bRequest) {
534 		case USB_REQ_SET_ADDRESS:
535 			/* set_address may come when a device is reset */
536 			dev_info(dev, "SetAddress Request (%d) to port %d\n",
537 				 ctrlreq->wValue, vdev->rhport);
538 
539 			usb_put_dev(vdev->udev);
540 			vdev->udev = usb_get_dev(urb->dev);
541 
542 			spin_lock(&vdev->ud.lock);
543 			vdev->ud.status = VDEV_ST_USED;
544 			spin_unlock(&vdev->ud.lock);
545 
546 			if (urb->status == -EINPROGRESS) {
547 				/* This request is successfully completed. */
548 				/* If not -EINPROGRESS, possibly unlinked. */
549 				urb->status = 0;
550 			}
551 
552 			goto no_need_xmit;
553 
554 		case USB_REQ_GET_DESCRIPTOR:
555 			if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
556 				usbip_dbg_vhci_hc(
557 					"Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
558 
559 			usb_put_dev(vdev->udev);
560 			vdev->udev = usb_get_dev(urb->dev);
561 			goto out;
562 
563 		default:
564 			/* NOT REACHED */
565 			dev_err(dev,
566 				"invalid request to devnum 0 bRequest %u, wValue %u\n",
567 				ctrlreq->bRequest,
568 				ctrlreq->wValue);
569 			ret =  -EINVAL;
570 			goto no_need_xmit;
571 		}
572 
573 	}
574 
575 out:
576 	vhci_tx_urb(urb, vdev);
577 	spin_unlock_irqrestore(&vhci->lock, flags);
578 
579 	return 0;
580 
581 no_need_xmit:
582 	usb_hcd_unlink_urb_from_ep(hcd, urb);
583 no_need_unlink:
584 	spin_unlock_irqrestore(&vhci->lock, flags);
585 	if (!ret)
586 		usb_hcd_giveback_urb(hcd, urb, urb->status);
587 	return ret;
588 }
589 
590 /*
591  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
592  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
593  * back its urb. For the driver unlinking the urb, the content of the urb is
594  * not important, but the calling to its completion handler is important; the
595  * completion of unlinking is notified by the completion handler.
596  *
597  *
598  * CLIENT SIDE
599  *
600  * - When vhci_hcd receives RET_SUBMIT,
601  *
602  *	- case 1a). the urb of the pdu is not unlinking.
603  *		- normal case
604  *		=> just give back the urb
605  *
606  *	- case 1b). the urb of the pdu is unlinking.
607  *		- usbip.ko will return a reply of the unlinking request.
608  *		=> give back the urb now and go to case 2b).
609  *
610  * - When vhci_hcd receives RET_UNLINK,
611  *
612  *	- case 2a). a submit request is still pending in vhci_hcd.
613  *		- urb was really pending in usbip.ko and urb_unlink_urb() was
614  *		  completed there.
615  *		=> free a pending submit request
616  *		=> notify unlink completeness by giving back the urb
617  *
618  *	- case 2b). a submit request is *not* pending in vhci_hcd.
619  *		- urb was already given back to the core driver.
620  *		=> do not give back the urb
621  *
622  *
623  * SERVER SIDE
624  *
625  * - When usbip receives CMD_UNLINK,
626  *
627  *	- case 3a). the urb of the unlink request is now in submission.
628  *		=> do usb_unlink_urb().
629  *		=> after the unlink is completed, send RET_UNLINK.
630  *
631  *	- case 3b). the urb of the unlink request is not in submission.
632  *		- may be already completed or never be received
633  *		=> send RET_UNLINK
634  *
635  */
636 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
637 {
638 	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
639 	struct vhci_priv *priv;
640 	struct vhci_device *vdev;
641 	unsigned long flags;
642 
643 	pr_info("dequeue a urb %p\n", urb);
644 
645 	spin_lock_irqsave(&vhci->lock, flags);
646 
647 	priv = urb->hcpriv;
648 	if (!priv) {
649 		/* URB was never linked! or will be soon given back by
650 		 * vhci_rx. */
651 		spin_unlock_irqrestore(&vhci->lock, flags);
652 		return -EIDRM;
653 	}
654 
655 	{
656 		int ret = 0;
657 
658 		ret = usb_hcd_check_unlink_urb(hcd, urb, status);
659 		if (ret) {
660 			spin_unlock_irqrestore(&vhci->lock, flags);
661 			return ret;
662 		}
663 	}
664 
665 	 /* send unlink request here? */
666 	vdev = priv->vdev;
667 
668 	if (!vdev->ud.tcp_socket) {
669 		/* tcp connection is closed */
670 		spin_lock(&vdev->priv_lock);
671 
672 		pr_info("device %p seems to be disconnected\n", vdev);
673 		list_del(&priv->list);
674 		kfree(priv);
675 		urb->hcpriv = NULL;
676 
677 		spin_unlock(&vdev->priv_lock);
678 
679 		/*
680 		 * If tcp connection is alive, we have sent CMD_UNLINK.
681 		 * vhci_rx will receive RET_UNLINK and give back the URB.
682 		 * Otherwise, we give back it here.
683 		 */
684 		pr_info("gives back urb %p\n", urb);
685 
686 		usb_hcd_unlink_urb_from_ep(hcd, urb);
687 
688 		spin_unlock_irqrestore(&vhci->lock, flags);
689 		usb_hcd_giveback_urb(vhci_to_hcd(vhci), urb, urb->status);
690 		spin_lock_irqsave(&vhci->lock, flags);
691 
692 	} else {
693 		/* tcp connection is alive */
694 		struct vhci_unlink *unlink;
695 
696 		spin_lock(&vdev->priv_lock);
697 
698 		/* setup CMD_UNLINK pdu */
699 		unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
700 		if (!unlink) {
701 			spin_unlock(&vdev->priv_lock);
702 			spin_unlock_irqrestore(&vhci->lock, flags);
703 			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
704 			return -ENOMEM;
705 		}
706 
707 		unlink->seqnum = atomic_inc_return(&vhci->seqnum);
708 		if (unlink->seqnum == 0xffff)
709 			pr_info("seqnum max\n");
710 
711 		unlink->unlink_seqnum = priv->seqnum;
712 
713 		pr_info("device %p seems to be still connected\n", vdev);
714 
715 		/* send cmd_unlink and try to cancel the pending URB in the
716 		 * peer */
717 		list_add_tail(&unlink->list, &vdev->unlink_tx);
718 		wake_up(&vdev->waitq_tx);
719 
720 		spin_unlock(&vdev->priv_lock);
721 	}
722 
723 	spin_unlock_irqrestore(&vhci->lock, flags);
724 
725 	usbip_dbg_vhci_hc("leave\n");
726 	return 0;
727 }
728 
729 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
730 {
731 	struct vhci_hcd *vhci = vdev_to_vhci(vdev);
732 	struct usb_hcd *hcd = vhci_to_hcd(vhci);
733 	struct vhci_unlink *unlink, *tmp;
734 	unsigned long flags;
735 
736 	spin_lock_irqsave(&vhci->lock, flags);
737 	spin_lock(&vdev->priv_lock);
738 
739 	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
740 		pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
741 		list_del(&unlink->list);
742 		kfree(unlink);
743 	}
744 
745 	while (!list_empty(&vdev->unlink_rx)) {
746 		struct urb *urb;
747 
748 		unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
749 			list);
750 
751 		/* give back URB of unanswered unlink request */
752 		pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
753 
754 		urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
755 		if (!urb) {
756 			pr_info("the urb (seqnum %lu) was already given back\n",
757 				unlink->unlink_seqnum);
758 			list_del(&unlink->list);
759 			kfree(unlink);
760 			continue;
761 		}
762 
763 		urb->status = -ENODEV;
764 
765 		usb_hcd_unlink_urb_from_ep(hcd, urb);
766 
767 		list_del(&unlink->list);
768 
769 		spin_unlock(&vdev->priv_lock);
770 		spin_unlock_irqrestore(&vhci->lock, flags);
771 
772 		usb_hcd_giveback_urb(hcd, urb, urb->status);
773 
774 		spin_lock_irqsave(&vhci->lock, flags);
775 		spin_lock(&vdev->priv_lock);
776 
777 		kfree(unlink);
778 	}
779 
780 	spin_unlock(&vdev->priv_lock);
781 	spin_unlock_irqrestore(&vhci->lock, flags);
782 }
783 
784 /*
785  * The important thing is that only one context begins cleanup.
786  * This is why error handling and cleanup become simple.
787  * We do not want to consider race condition as possible.
788  */
789 static void vhci_shutdown_connection(struct usbip_device *ud)
790 {
791 	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
792 
793 	/* need this? see stub_dev.c */
794 	if (ud->tcp_socket) {
795 		pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
796 		kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
797 	}
798 
799 	/* kill threads related to this sdev */
800 	if (vdev->ud.tcp_rx) {
801 		kthread_stop_put(vdev->ud.tcp_rx);
802 		vdev->ud.tcp_rx = NULL;
803 	}
804 	if (vdev->ud.tcp_tx) {
805 		kthread_stop_put(vdev->ud.tcp_tx);
806 		vdev->ud.tcp_tx = NULL;
807 	}
808 	pr_info("stop threads\n");
809 
810 	/* active connection is closed */
811 	if (vdev->ud.tcp_socket) {
812 		sockfd_put(vdev->ud.tcp_socket);
813 		vdev->ud.tcp_socket = NULL;
814 	}
815 	pr_info("release socket\n");
816 
817 	vhci_device_unlink_cleanup(vdev);
818 
819 	/*
820 	 * rh_port_disconnect() is a trigger of ...
821 	 *   usb_disable_device():
822 	 *	disable all the endpoints for a USB device.
823 	 *   usb_disable_endpoint():
824 	 *	disable endpoints. pending urbs are unlinked(dequeued).
825 	 *
826 	 * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
827 	 * detached device should release used urbs in a cleanup function (i.e.
828 	 * xxx_disconnect()). Therefore, vhci_hcd does not need to release
829 	 * pushed urbs and their private data in this function.
830 	 *
831 	 * NOTE: vhci_dequeue() must be considered carefully. When shutting down
832 	 * a connection, vhci_shutdown_connection() expects vhci_dequeue()
833 	 * gives back pushed urbs and frees their private data by request of
834 	 * the cleanup function of a USB driver. When unlinking a urb with an
835 	 * active connection, vhci_dequeue() does not give back the urb which
836 	 * is actually given back by vhci_rx after receiving its return pdu.
837 	 *
838 	 */
839 	rh_port_disconnect(vdev);
840 
841 	pr_info("disconnect device\n");
842 }
843 
844 
845 static void vhci_device_reset(struct usbip_device *ud)
846 {
847 	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
848 	unsigned long flags;
849 
850 	spin_lock_irqsave(&ud->lock, flags);
851 
852 	vdev->speed  = 0;
853 	vdev->devid  = 0;
854 
855 	usb_put_dev(vdev->udev);
856 	vdev->udev = NULL;
857 
858 	if (ud->tcp_socket) {
859 		sockfd_put(ud->tcp_socket);
860 		ud->tcp_socket = NULL;
861 	}
862 	ud->status = VDEV_ST_NULL;
863 
864 	spin_unlock_irqrestore(&ud->lock, flags);
865 }
866 
867 static void vhci_device_unusable(struct usbip_device *ud)
868 {
869 	unsigned long flags;
870 
871 	spin_lock_irqsave(&ud->lock, flags);
872 	ud->status = VDEV_ST_ERROR;
873 	spin_unlock_irqrestore(&ud->lock, flags);
874 }
875 
876 static void vhci_device_init(struct vhci_device *vdev)
877 {
878 	memset(vdev, 0, sizeof(struct vhci_device));
879 
880 	vdev->ud.side   = USBIP_VHCI;
881 	vdev->ud.status = VDEV_ST_NULL;
882 	spin_lock_init(&vdev->ud.lock);
883 
884 	INIT_LIST_HEAD(&vdev->priv_rx);
885 	INIT_LIST_HEAD(&vdev->priv_tx);
886 	INIT_LIST_HEAD(&vdev->unlink_tx);
887 	INIT_LIST_HEAD(&vdev->unlink_rx);
888 	spin_lock_init(&vdev->priv_lock);
889 
890 	init_waitqueue_head(&vdev->waitq_tx);
891 
892 	vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
893 	vdev->ud.eh_ops.reset = vhci_device_reset;
894 	vdev->ud.eh_ops.unusable = vhci_device_unusable;
895 
896 	usbip_start_eh(&vdev->ud);
897 }
898 
899 static int hcd_name_to_id(const char *name)
900 {
901 	char *c;
902 	long val;
903 	int ret;
904 
905 	c = strchr(name, '.');
906 	if (c == NULL)
907 		return 0;
908 
909 	ret = kstrtol(c+1, 10, &val);
910 	if (ret < 0)
911 		return ret;
912 
913 	return val;
914 }
915 
916 static int vhci_start(struct usb_hcd *hcd)
917 {
918 	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
919 	int id, rhport;
920 	int err = 0;
921 
922 	usbip_dbg_vhci_hc("enter vhci_start\n");
923 
924 	/* initialize private data of usb_hcd */
925 
926 	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
927 		struct vhci_device *vdev = &vhci->vdev[rhport];
928 
929 		vhci_device_init(vdev);
930 		vdev->rhport = rhport;
931 	}
932 
933 	atomic_set(&vhci->seqnum, 0);
934 	spin_lock_init(&vhci->lock);
935 
936 	hcd->power_budget = 0; /* no limit */
937 	hcd->uses_new_polling = 1;
938 
939 	id = hcd_name_to_id(hcd_name(hcd));
940 	if (id < 0) {
941 		pr_err("invalid vhci name %s\n", hcd_name(hcd));
942 		return -EINVAL;
943 	}
944 
945 	/* vhci_hcd is now ready to be controlled through sysfs */
946 	if (id == 0) {
947 		err = vhci_init_attr_group();
948 		if (err) {
949 			pr_err("init attr group\n");
950 			return err;
951 		}
952 		err = sysfs_create_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
953 		if (err) {
954 			pr_err("create sysfs files\n");
955 			vhci_finish_attr_group();
956 			return err;
957 		}
958 		pr_info("created sysfs %s\n", hcd_name(hcd));
959 	}
960 
961 	return 0;
962 }
963 
964 static void vhci_stop(struct usb_hcd *hcd)
965 {
966 	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
967 	int id, rhport;
968 
969 	usbip_dbg_vhci_hc("stop VHCI controller\n");
970 
971 	/* 1. remove the userland interface of vhci_hcd */
972 	id = hcd_name_to_id(hcd_name(hcd));
973 	if (id == 0) {
974 		sysfs_remove_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
975 		vhci_finish_attr_group();
976 	}
977 
978 	/* 2. shutdown all the ports of vhci_hcd */
979 	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
980 		struct vhci_device *vdev = &vhci->vdev[rhport];
981 
982 		usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
983 		usbip_stop_eh(&vdev->ud);
984 	}
985 }
986 
987 static int vhci_get_frame_number(struct usb_hcd *hcd)
988 {
989 	dev_err_ratelimited(&hcd->self.root_hub->dev, "Not yet implemented\n");
990 	return 0;
991 }
992 
993 #ifdef CONFIG_PM
994 
995 /* FIXME: suspend/resume */
996 static int vhci_bus_suspend(struct usb_hcd *hcd)
997 {
998 	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
999 	unsigned long flags;
1000 
1001 	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1002 
1003 	spin_lock_irqsave(&vhci->lock, flags);
1004 	hcd->state = HC_STATE_SUSPENDED;
1005 	spin_unlock_irqrestore(&vhci->lock, flags);
1006 
1007 	return 0;
1008 }
1009 
1010 static int vhci_bus_resume(struct usb_hcd *hcd)
1011 {
1012 	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1013 	int rc = 0;
1014 	unsigned long flags;
1015 
1016 	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1017 
1018 	spin_lock_irqsave(&vhci->lock, flags);
1019 	if (!HCD_HW_ACCESSIBLE(hcd))
1020 		rc = -ESHUTDOWN;
1021 	else
1022 		hcd->state = HC_STATE_RUNNING;
1023 	spin_unlock_irqrestore(&vhci->lock, flags);
1024 
1025 	return rc;
1026 }
1027 
1028 #else
1029 
1030 #define vhci_bus_suspend      NULL
1031 #define vhci_bus_resume       NULL
1032 #endif
1033 
1034 static struct hc_driver vhci_hc_driver = {
1035 	.description	= driver_name,
1036 	.product_desc	= driver_desc,
1037 	.hcd_priv_size	= sizeof(struct vhci_hcd),
1038 
1039 	.flags		= HCD_USB2,
1040 
1041 	.start		= vhci_start,
1042 	.stop		= vhci_stop,
1043 
1044 	.urb_enqueue	= vhci_urb_enqueue,
1045 	.urb_dequeue	= vhci_urb_dequeue,
1046 
1047 	.get_frame_number = vhci_get_frame_number,
1048 
1049 	.hub_status_data = vhci_hub_status,
1050 	.hub_control    = vhci_hub_control,
1051 	.bus_suspend	= vhci_bus_suspend,
1052 	.bus_resume	= vhci_bus_resume,
1053 };
1054 
1055 static int vhci_hcd_probe(struct platform_device *pdev)
1056 {
1057 	struct usb_hcd		*hcd;
1058 	int			ret;
1059 
1060 	usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1061 
1062 	/*
1063 	 * Allocate and initialize hcd.
1064 	 * Our private data is also allocated automatically.
1065 	 */
1066 	hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1067 	if (!hcd) {
1068 		pr_err("create hcd failed\n");
1069 		return -ENOMEM;
1070 	}
1071 	hcd->has_tt = 1;
1072 
1073 	/*
1074 	 * Finish generic HCD structure initialization and register.
1075 	 * Call the driver's reset() and start() routines.
1076 	 */
1077 	ret = usb_add_hcd(hcd, 0, 0);
1078 	if (ret != 0) {
1079 		pr_err("usb_add_hcd failed %d\n", ret);
1080 		usb_put_hcd(hcd);
1081 		return ret;
1082 	}
1083 
1084 	usbip_dbg_vhci_hc("bye\n");
1085 	return 0;
1086 }
1087 
1088 static int vhci_hcd_remove(struct platform_device *pdev)
1089 {
1090 	struct usb_hcd	*hcd;
1091 
1092 	hcd = platform_get_drvdata(pdev);
1093 	if (!hcd)
1094 		return 0;
1095 
1096 	/*
1097 	 * Disconnects the root hub,
1098 	 * then reverses the effects of usb_add_hcd(),
1099 	 * invoking the HCD's stop() methods.
1100 	 */
1101 	usb_remove_hcd(hcd);
1102 	usb_put_hcd(hcd);
1103 
1104 	return 0;
1105 }
1106 
1107 #ifdef CONFIG_PM
1108 
1109 /* what should happen for USB/IP under suspend/resume? */
1110 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1111 {
1112 	struct usb_hcd *hcd;
1113 	struct vhci_hcd *vhci;
1114 	int rhport;
1115 	int connected = 0;
1116 	int ret = 0;
1117 	unsigned long flags;
1118 
1119 	hcd = platform_get_drvdata(pdev);
1120 	if (!hcd)
1121 		return 0;
1122 	vhci = hcd_to_vhci(hcd);
1123 
1124 	spin_lock_irqsave(&vhci->lock, flags);
1125 
1126 	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++)
1127 		if (vhci->port_status[rhport] & USB_PORT_STAT_CONNECTION)
1128 			connected += 1;
1129 
1130 	spin_unlock_irqrestore(&vhci->lock, flags);
1131 
1132 	if (connected > 0) {
1133 		dev_info(&pdev->dev,
1134 			 "We have %d active connection%s. Do not suspend.\n",
1135 			 connected, (connected == 1 ? "" : "s"));
1136 		ret =  -EBUSY;
1137 	} else {
1138 		dev_info(&pdev->dev, "suspend vhci_hcd");
1139 		clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1140 	}
1141 
1142 	return ret;
1143 }
1144 
1145 static int vhci_hcd_resume(struct platform_device *pdev)
1146 {
1147 	struct usb_hcd *hcd;
1148 
1149 	dev_dbg(&pdev->dev, "%s\n", __func__);
1150 
1151 	hcd = platform_get_drvdata(pdev);
1152 	if (!hcd)
1153 		return 0;
1154 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1155 	usb_hcd_poll_rh_status(hcd);
1156 
1157 	return 0;
1158 }
1159 
1160 #else
1161 
1162 #define vhci_hcd_suspend	NULL
1163 #define vhci_hcd_resume		NULL
1164 
1165 #endif
1166 
1167 static struct platform_driver vhci_driver = {
1168 	.probe	= vhci_hcd_probe,
1169 	.remove	= vhci_hcd_remove,
1170 	.suspend = vhci_hcd_suspend,
1171 	.resume	= vhci_hcd_resume,
1172 	.driver	= {
1173 		.name = driver_name,
1174 	},
1175 };
1176 
1177 static int add_platform_device(int id)
1178 {
1179 	struct platform_device *pdev;
1180 	int dev_nr;
1181 
1182 	if (id == 0)
1183 		dev_nr = -1;
1184 	else
1185 		dev_nr = id;
1186 
1187 	pdev = platform_device_register_simple(driver_name, dev_nr, NULL, 0);
1188 	if (IS_ERR(pdev))
1189 		return PTR_ERR(pdev);
1190 
1191 	*(vhci_pdevs + id) = pdev;
1192 	return 0;
1193 }
1194 
1195 static void del_platform_devices(void)
1196 {
1197 	struct platform_device *pdev;
1198 	int i;
1199 
1200 	for (i = 0; i < vhci_num_controllers; i++) {
1201 		pdev = *(vhci_pdevs + i);
1202 		if (pdev != NULL)
1203 			platform_device_unregister(pdev);
1204 		*(vhci_pdevs + i) = NULL;
1205 	}
1206 	sysfs_remove_link(&platform_bus.kobj, driver_name);
1207 }
1208 
1209 static int __init vhci_hcd_init(void)
1210 {
1211 	int i, ret;
1212 
1213 	if (usb_disabled())
1214 		return -ENODEV;
1215 
1216 	if (vhci_num_controllers < 1)
1217 		vhci_num_controllers = 1;
1218 
1219 	vhci_pdevs = kcalloc(vhci_num_controllers, sizeof(void *), GFP_KERNEL);
1220 	if (vhci_pdevs == NULL)
1221 		return -ENOMEM;
1222 
1223 	ret = platform_driver_register(&vhci_driver);
1224 	if (ret)
1225 		goto err_driver_register;
1226 
1227 	for (i = 0; i < vhci_num_controllers; i++) {
1228 		ret = add_platform_device(i);
1229 		if (ret)
1230 			goto err_platform_device_register;
1231 	}
1232 
1233 	pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1234 	return ret;
1235 
1236 err_platform_device_register:
1237 	del_platform_devices();
1238 	platform_driver_unregister(&vhci_driver);
1239 err_driver_register:
1240 	kfree(vhci_pdevs);
1241 	return ret;
1242 }
1243 
1244 static void __exit vhci_hcd_exit(void)
1245 {
1246 	del_platform_devices();
1247 	platform_driver_unregister(&vhci_driver);
1248 	kfree(vhci_pdevs);
1249 }
1250 
1251 module_init(vhci_hcd_init);
1252 module_exit(vhci_hcd_exit);
1253 
1254 MODULE_AUTHOR(DRIVER_AUTHOR);
1255 MODULE_DESCRIPTION(DRIVER_DESC);
1256 MODULE_LICENSE("GPL");
1257 MODULE_VERSION(USBIP_VERSION);
1258