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/init.h>
21#include <linux/kernel.h>
22#include <linux/kthread.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
25#include <linux/slab.h>
26
27#include "usbip_common.h"
28#include "vhci.h"
29
30#define DRIVER_AUTHOR "Takahiro Hirofuchi"
31#define DRIVER_DESC "USB/IP 'Virtual' Host Controller (VHCI) Driver"
32
33/*
34 * TODO
35 *	- update root hub emulation
36 *	- move the emulation code to userland ?
37 *		porting to other operating systems
38 *		minimize kernel code
39 *	- add suspend/resume code
40 *	- clean up everything
41 */
42
43/* See usb gadget dummy hcd */
44
45static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
46static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
47			    u16 wIndex, char *buff, u16 wLength);
48static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
49			    gfp_t mem_flags);
50static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
51static int vhci_start(struct usb_hcd *vhci_hcd);
52static void vhci_stop(struct usb_hcd *hcd);
53static int vhci_get_frame_number(struct usb_hcd *hcd);
54
55static const char driver_name[] = "vhci_hcd";
56static const char driver_desc[] = "USB/IP Virtual Host Controller";
57
58struct vhci_hcd *the_controller;
59
60static const char * const bit_desc[] = {
61	"CONNECTION",		/*0*/
62	"ENABLE",		/*1*/
63	"SUSPEND",		/*2*/
64	"OVER_CURRENT",		/*3*/
65	"RESET",		/*4*/
66	"R5",			/*5*/
67	"R6",			/*6*/
68	"R7",			/*7*/
69	"POWER",		/*8*/
70	"LOWSPEED",		/*9*/
71	"HIGHSPEED",		/*10*/
72	"PORT_TEST",		/*11*/
73	"INDICATOR",		/*12*/
74	"R13",			/*13*/
75	"R14",			/*14*/
76	"R15",			/*15*/
77	"C_CONNECTION",		/*16*/
78	"C_ENABLE",		/*17*/
79	"C_SUSPEND",		/*18*/
80	"C_OVER_CURRENT",	/*19*/
81	"C_RESET",		/*20*/
82	"R21",			/*21*/
83	"R22",			/*22*/
84	"R23",			/*23*/
85	"R24",			/*24*/
86	"R25",			/*25*/
87	"R26",			/*26*/
88	"R27",			/*27*/
89	"R28",			/*28*/
90	"R29",			/*29*/
91	"R30",			/*30*/
92	"R31",			/*31*/
93};
94
95static void dump_port_status_diff(u32 prev_status, u32 new_status)
96{
97	int i = 0;
98	u32 bit = 1;
99
100	pr_debug("status prev -> new: %08x -> %08x\n", prev_status, new_status);
101	while (bit) {
102		u32 prev = prev_status & bit;
103		u32 new = new_status & bit;
104		char change;
105
106		if (!prev && new)
107			change = '+';
108		else if (prev && !new)
109			change = '-';
110		else
111			change = ' ';
112
113		if (prev || new)
114			pr_debug(" %c%s\n", change, bit_desc[i]);
115		bit <<= 1;
116		i++;
117	}
118	pr_debug("\n");
119}
120
121void rh_port_connect(int rhport, enum usb_device_speed speed)
122{
123	unsigned long	flags;
124
125	usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
126
127	spin_lock_irqsave(&the_controller->lock, flags);
128
129	the_controller->port_status[rhport] |= USB_PORT_STAT_CONNECTION
130		| (1 << USB_PORT_FEAT_C_CONNECTION);
131
132	switch (speed) {
133	case USB_SPEED_HIGH:
134		the_controller->port_status[rhport] |= USB_PORT_STAT_HIGH_SPEED;
135		break;
136	case USB_SPEED_LOW:
137		the_controller->port_status[rhport] |= USB_PORT_STAT_LOW_SPEED;
138		break;
139	default:
140		break;
141	}
142
143	/* spin_lock(&the_controller->vdev[rhport].ud.lock);
144	 * the_controller->vdev[rhport].ud.status = VDEV_CONNECT;
145	 * spin_unlock(&the_controller->vdev[rhport].ud.lock); */
146
147	spin_unlock_irqrestore(&the_controller->lock, flags);
148
149	usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
150}
151
152void rh_port_disconnect(int rhport)
153{
154	unsigned long flags;
155
156	usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
157
158	spin_lock_irqsave(&the_controller->lock, flags);
159	/* stop_activity(dum, driver); */
160	the_controller->port_status[rhport] &= ~USB_PORT_STAT_CONNECTION;
161	the_controller->port_status[rhport] |=
162					(1 << USB_PORT_FEAT_C_CONNECTION);
163
164	/* not yet complete the disconnection
165	 * spin_lock(&vdev->ud.lock);
166	 * vdev->ud.status = VHC_ST_DISCONNECT;
167	 * spin_unlock(&vdev->ud.lock); */
168
169	spin_unlock_irqrestore(&the_controller->lock, flags);
170	usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
171}
172
173#define PORT_C_MASK				\
174	((USB_PORT_STAT_C_CONNECTION		\
175	  | USB_PORT_STAT_C_ENABLE		\
176	  | USB_PORT_STAT_C_SUSPEND		\
177	  | USB_PORT_STAT_C_OVERCURRENT		\
178	  | USB_PORT_STAT_C_RESET) << 16)
179
180/*
181 * This function is almostly the same as dummy_hcd.c:dummy_hub_status() without
182 * suspend/resume support. But, it is modified to provide multiple ports.
183 *
184 * @buf: a bitmap to show which port status has been changed.
185 *  bit  0: reserved or used for another purpose?
186 *  bit  1: the status of port 0 has been changed.
187 *  bit  2: the status of port 1 has been changed.
188 *  ...
189 *  bit  7: the status of port 6 has been changed.
190 *  bit  8: the status of port 7 has been changed.
191 *  ...
192 *  bit 15: the status of port 14 has been changed.
193 *
194 * So, the maximum number of ports is 31 ( port 0 to port 30) ?
195 *
196 * The return value is the actual transferred length in byte. If nothing has
197 * been changed, return 0. In the case that the number of ports is less than or
198 * equal to 6 (VHCI_NPORTS==7), return 1.
199 *
200 */
201static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
202{
203	struct vhci_hcd	*vhci;
204	unsigned long	flags;
205	int		retval = 0;
206
207	/* the enough buffer is allocated according to USB_MAXCHILDREN */
208	unsigned long	*event_bits = (unsigned long *) buf;
209	int		rhport;
210	int		changed = 0;
211
212	*event_bits = 0;
213
214	vhci = hcd_to_vhci(hcd);
215
216	spin_lock_irqsave(&vhci->lock, flags);
217	if (!HCD_HW_ACCESSIBLE(hcd)) {
218		usbip_dbg_vhci_rh("hw accessible flag in on?\n");
219		goto done;
220	}
221
222	/* check pseudo status register for each port */
223	for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
224		if ((vhci->port_status[rhport] & PORT_C_MASK)) {
225			/* The status of a port has been changed, */
226			usbip_dbg_vhci_rh("port %d is changed\n", rhport);
227
228			*event_bits |= 1 << (rhport + 1);
229			changed = 1;
230		}
231	}
232
233	pr_info("changed %d\n", changed);
234
235	if (hcd->state == HC_STATE_SUSPENDED)
236		usb_hcd_resume_root_hub(hcd);
237
238	if (changed)
239		retval = 1 + (VHCI_NPORTS / 8);
240	else
241		retval = 0;
242
243done:
244	spin_unlock_irqrestore(&vhci->lock, flags);
245	return retval;
246}
247
248/* See hub_configure in hub.c */
249static inline void hub_descriptor(struct usb_hub_descriptor *desc)
250{
251	memset(desc, 0, sizeof(*desc));
252	desc->bDescriptorType = 0x29;
253	desc->bDescLength = 9;
254	desc->wHubCharacteristics = (__force __u16)
255		(__constant_cpu_to_le16(0x0001));
256	desc->bNbrPorts = VHCI_NPORTS;
257	desc->u.hs.DeviceRemovable[0] = 0xff;
258	desc->u.hs.DeviceRemovable[1] = 0xff;
259}
260
261static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
262			    u16 wIndex, char *buf, u16 wLength)
263{
264	struct vhci_hcd	*dum;
265	int             retval = 0;
266	unsigned long   flags;
267	int		rhport;
268
269	u32 prev_port_status[VHCI_NPORTS];
270
271	if (!HCD_HW_ACCESSIBLE(hcd))
272		return -ETIMEDOUT;
273
274	/*
275	 * NOTE:
276	 * wIndex shows the port number and begins from 1.
277	 */
278	usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
279			  wIndex);
280	if (wIndex > VHCI_NPORTS)
281		pr_err("invalid port number %d\n", wIndex);
282	rhport = ((__u8)(wIndex & 0x00ff)) - 1;
283
284	dum = hcd_to_vhci(hcd);
285
286	spin_lock_irqsave(&dum->lock, flags);
287
288	/* store old status and compare now and old later */
289	if (usbip_dbg_flag_vhci_rh) {
290		memcpy(prev_port_status, dum->port_status,
291			sizeof(prev_port_status));
292	}
293
294	switch (typeReq) {
295	case ClearHubFeature:
296		usbip_dbg_vhci_rh(" ClearHubFeature\n");
297		break;
298	case ClearPortFeature:
299		switch (wValue) {
300		case USB_PORT_FEAT_SUSPEND:
301			if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
302				/* 20msec signaling */
303				dum->resuming = 1;
304				dum->re_timeout =
305					jiffies + msecs_to_jiffies(20);
306			}
307			break;
308		case USB_PORT_FEAT_POWER:
309			usbip_dbg_vhci_rh(" ClearPortFeature: "
310					  "USB_PORT_FEAT_POWER\n");
311			dum->port_status[rhport] = 0;
312			/* dum->address = 0; */
313			/* dum->hdev = 0; */
314			dum->resuming = 0;
315			break;
316		case USB_PORT_FEAT_C_RESET:
317			usbip_dbg_vhci_rh(" ClearPortFeature: "
318					  "USB_PORT_FEAT_C_RESET\n");
319			switch (dum->vdev[rhport].speed) {
320			case USB_SPEED_HIGH:
321				dum->port_status[rhport] |=
322					USB_PORT_STAT_HIGH_SPEED;
323				break;
324			case USB_SPEED_LOW:
325				dum->port_status[rhport] |=
326					USB_PORT_STAT_LOW_SPEED;
327				break;
328			default:
329				break;
330			}
331		default:
332			usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
333					  wValue);
334			dum->port_status[rhport] &= ~(1 << wValue);
335			break;
336		}
337		break;
338	case GetHubDescriptor:
339		usbip_dbg_vhci_rh(" GetHubDescriptor\n");
340		hub_descriptor((struct usb_hub_descriptor *) buf);
341		break;
342	case GetHubStatus:
343		usbip_dbg_vhci_rh(" GetHubStatus\n");
344		*(__le32 *) buf = __constant_cpu_to_le32(0);
345		break;
346	case GetPortStatus:
347		usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
348		if (wIndex > VHCI_NPORTS || wIndex < 1) {
349			pr_err("invalid port number %d\n", wIndex);
350			retval = -EPIPE;
351		}
352
353		/* we do no care of resume. */
354
355		/* whoever resets or resumes must GetPortStatus to
356		 * complete it!!
357		 *                                   */
358		if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
359			dum->port_status[rhport] |=
360				(1 << USB_PORT_FEAT_C_SUSPEND);
361			dum->port_status[rhport] &=
362				~(1 << USB_PORT_FEAT_SUSPEND);
363			dum->resuming = 0;
364			dum->re_timeout = 0;
365			/* if (dum->driver && dum->driver->resume) {
366			 *	spin_unlock (&dum->lock);
367			 *	dum->driver->resume (&dum->gadget);
368			 *	spin_lock (&dum->lock);
369			 * } */
370		}
371
372		if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
373		    0 && time_after(jiffies, dum->re_timeout)) {
374			dum->port_status[rhport] |=
375				(1 << USB_PORT_FEAT_C_RESET);
376			dum->port_status[rhport] &=
377				~(1 << USB_PORT_FEAT_RESET);
378			dum->re_timeout = 0;
379
380			if (dum->vdev[rhport].ud.status ==
381			    VDEV_ST_NOTASSIGNED) {
382				usbip_dbg_vhci_rh(" enable rhport %d "
383						  "(status %u)\n",
384						  rhport,
385						  dum->vdev[rhport].ud.status);
386				dum->port_status[rhport] |=
387					USB_PORT_STAT_ENABLE;
388			}
389		}
390		((u16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
391		((u16 *) buf)[1] = cpu_to_le16(dum->port_status[rhport] >> 16);
392
393		usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
394				  ((u16 *)buf)[1]);
395		break;
396	case SetHubFeature:
397		usbip_dbg_vhci_rh(" SetHubFeature\n");
398		retval = -EPIPE;
399		break;
400	case SetPortFeature:
401		switch (wValue) {
402		case USB_PORT_FEAT_SUSPEND:
403			usbip_dbg_vhci_rh(" SetPortFeature: "
404					  "USB_PORT_FEAT_SUSPEND\n");
405			break;
406		case USB_PORT_FEAT_RESET:
407			usbip_dbg_vhci_rh(" SetPortFeature: "
408					  "USB_PORT_FEAT_RESET\n");
409			/* if it's already running, disconnect first */
410			if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
411				dum->port_status[rhport] &=
412					~(USB_PORT_STAT_ENABLE |
413					  USB_PORT_STAT_LOW_SPEED |
414					  USB_PORT_STAT_HIGH_SPEED);
415				/* FIXME test that code path! */
416			}
417			/* 50msec reset signaling */
418			dum->re_timeout = jiffies + msecs_to_jiffies(50);
419
420			/* FALLTHROUGH */
421		default:
422			usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
423					  wValue);
424			dum->port_status[rhport] |= (1 << wValue);
425			break;
426		}
427		break;
428
429	default:
430		pr_err("default: no such request\n");
431		/* dev_dbg (hardware,
432		 *		"hub control req%04x v%04x i%04x l%d\n",
433		 *		typeReq, wValue, wIndex, wLength); */
434
435		/* "protocol stall" on error */
436		retval = -EPIPE;
437	}
438
439	if (usbip_dbg_flag_vhci_rh) {
440		pr_debug("port %d\n", rhport);
441		/* Only dump valid port status */
442		if (rhport >= 0) {
443			dump_port_status_diff(prev_port_status[rhport],
444					      dum->port_status[rhport]);
445		}
446	}
447	usbip_dbg_vhci_rh(" bye\n");
448
449	spin_unlock_irqrestore(&dum->lock, flags);
450
451	return retval;
452}
453
454static struct vhci_device *get_vdev(struct usb_device *udev)
455{
456	int i;
457
458	if (!udev)
459		return NULL;
460
461	for (i = 0; i < VHCI_NPORTS; i++)
462		if (the_controller->vdev[i].udev == udev)
463			return port_to_vdev(i);
464
465	return NULL;
466}
467
468static void vhci_tx_urb(struct urb *urb)
469{
470	struct vhci_device *vdev = get_vdev(urb->dev);
471	struct vhci_priv *priv;
472	unsigned long flag;
473
474	if (!vdev) {
475		pr_err("could not get virtual device");
476		/* BUG(); */
477		return;
478	}
479
480	priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
481
482	spin_lock_irqsave(&vdev->priv_lock, flag);
483
484	if (!priv) {
485		dev_err(&urb->dev->dev, "malloc vhci_priv\n");
486		spin_unlock_irqrestore(&vdev->priv_lock, flag);
487		usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
488		return;
489	}
490
491	priv->seqnum = atomic_inc_return(&the_controller->seqnum);
492	if (priv->seqnum == 0xffff)
493		dev_info(&urb->dev->dev, "seqnum max\n");
494
495	priv->vdev = vdev;
496	priv->urb = urb;
497
498	urb->hcpriv = (void *) priv;
499
500	list_add_tail(&priv->list, &vdev->priv_tx);
501
502	wake_up(&vdev->waitq_tx);
503	spin_unlock_irqrestore(&vdev->priv_lock, flag);
504}
505
506static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
507			    gfp_t mem_flags)
508{
509	struct device *dev = &urb->dev->dev;
510	int ret = 0;
511	unsigned long flags;
512	struct vhci_device *vdev;
513
514	usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
515			  hcd, urb, mem_flags);
516
517	/* patch to usb_sg_init() is in 2.5.60 */
518	BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
519
520	spin_lock_irqsave(&the_controller->lock, flags);
521
522	if (urb->status != -EINPROGRESS) {
523		dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
524		spin_unlock_irqrestore(&the_controller->lock, flags);
525		return urb->status;
526	}
527
528	vdev = port_to_vdev(urb->dev->portnum-1);
529
530	/* refuse enqueue for dead connection */
531	spin_lock(&vdev->ud.lock);
532	if (vdev->ud.status == VDEV_ST_NULL ||
533	    vdev->ud.status == VDEV_ST_ERROR) {
534		dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
535		spin_unlock(&vdev->ud.lock);
536		spin_unlock_irqrestore(&the_controller->lock, flags);
537		return -ENODEV;
538	}
539	spin_unlock(&vdev->ud.lock);
540
541	ret = usb_hcd_link_urb_to_ep(hcd, urb);
542	if (ret)
543		goto no_need_unlink;
544
545	/*
546	 * The enumeration process is as follows;
547	 *
548	 *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
549	 *     to get max packet length of default pipe
550	 *
551	 *  2. Set_Address request to DevAddr(0) EndPoint(0)
552	 *
553	 */
554	if (usb_pipedevice(urb->pipe) == 0) {
555		__u8 type = usb_pipetype(urb->pipe);
556		struct usb_ctrlrequest *ctrlreq =
557			(struct usb_ctrlrequest *) urb->setup_packet;
558
559		if (type != PIPE_CONTROL || !ctrlreq) {
560			dev_err(dev, "invalid request to devnum 0\n");
561			ret = -EINVAL;
562			goto no_need_xmit;
563		}
564
565		switch (ctrlreq->bRequest) {
566		case USB_REQ_SET_ADDRESS:
567			/* set_address may come when a device is reset */
568			dev_info(dev, "SetAddress Request (%d) to port %d\n",
569				 ctrlreq->wValue, vdev->rhport);
570
571			if (vdev->udev)
572				usb_put_dev(vdev->udev);
573			vdev->udev = usb_get_dev(urb->dev);
574
575			spin_lock(&vdev->ud.lock);
576			vdev->ud.status = VDEV_ST_USED;
577			spin_unlock(&vdev->ud.lock);
578
579			if (urb->status == -EINPROGRESS) {
580				/* This request is successfully completed. */
581				/* If not -EINPROGRESS, possibly unlinked. */
582				urb->status = 0;
583			}
584
585			goto no_need_xmit;
586
587		case USB_REQ_GET_DESCRIPTOR:
588			if (ctrlreq->wValue == (USB_DT_DEVICE << 8))
589				usbip_dbg_vhci_hc("Not yet?: "
590						  "Get_Descriptor to device 0 "
591						  "(get max pipe size)\n");
592
593			if (vdev->udev)
594				usb_put_dev(vdev->udev);
595			vdev->udev = usb_get_dev(urb->dev);
596			goto out;
597
598		default:
599			/* NOT REACHED */
600			dev_err(dev, "invalid request to devnum 0 bRequest %u, "
601				"wValue %u\n", ctrlreq->bRequest,
602				ctrlreq->wValue);
603			ret =  -EINVAL;
604			goto no_need_xmit;
605		}
606
607	}
608
609out:
610	vhci_tx_urb(urb);
611	spin_unlock_irqrestore(&the_controller->lock, flags);
612
613	return 0;
614
615no_need_xmit:
616	usb_hcd_unlink_urb_from_ep(hcd, urb);
617no_need_unlink:
618	spin_unlock_irqrestore(&the_controller->lock, flags);
619	usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
620	return ret;
621}
622
623/*
624 * vhci_rx gives back the urb after receiving the reply of the urb.  If an
625 * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
626 * back its urb. For the driver unlinking the urb, the content of the urb is
627 * not important, but the calling to its completion handler is important; the
628 * completion of unlinking is notified by the completion handler.
629 *
630 *
631 * CLIENT SIDE
632 *
633 * - When vhci_hcd receives RET_SUBMIT,
634 *
635 *	- case 1a). the urb of the pdu is not unlinking.
636 *		- normal case
637 *		=> just give back the urb
638 *
639 *	- case 1b). the urb of the pdu is unlinking.
640 *		- usbip.ko will return a reply of the unlinking request.
641 *		=> give back the urb now and go to case 2b).
642 *
643 * - When vhci_hcd receives RET_UNLINK,
644 *
645 *	- case 2a). a submit request is still pending in vhci_hcd.
646 *		- urb was really pending in usbip.ko and urb_unlink_urb() was
647 *		  completed there.
648 *		=> free a pending submit request
649 *		=> notify unlink completeness by giving back the urb
650 *
651 *	- case 2b). a submit request is *not* pending in vhci_hcd.
652 *		- urb was already given back to the core driver.
653 *		=> do not give back the urb
654 *
655 *
656 * SERVER SIDE
657 *
658 * - When usbip receives CMD_UNLINK,
659 *
660 *	- case 3a). the urb of the unlink request is now in submission.
661 *		=> do usb_unlink_urb().
662 *		=> after the unlink is completed, send RET_UNLINK.
663 *
664 *	- case 3b). the urb of the unlink request is not in submission.
665 *		- may be already completed or never be received
666 *		=> send RET_UNLINK
667 *
668 */
669static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
670{
671	unsigned long flags;
672	struct vhci_priv *priv;
673	struct vhci_device *vdev;
674
675	pr_info("dequeue a urb %p\n", urb);
676
677	spin_lock_irqsave(&the_controller->lock, flags);
678
679	priv = urb->hcpriv;
680	if (!priv) {
681		/* URB was never linked! or will be soon given back by
682		 * vhci_rx. */
683		spin_unlock_irqrestore(&the_controller->lock, flags);
684		return 0;
685	}
686
687	{
688		int ret = 0;
689		ret = usb_hcd_check_unlink_urb(hcd, urb, status);
690		if (ret) {
691			spin_unlock_irqrestore(&the_controller->lock, flags);
692			return ret;
693		}
694	}
695
696	 /* send unlink request here? */
697	vdev = priv->vdev;
698
699	if (!vdev->ud.tcp_socket) {
700		/* tcp connection is closed */
701		unsigned long flags2;
702
703		spin_lock_irqsave(&vdev->priv_lock, flags2);
704
705		pr_info("device %p seems to be disconnected\n", vdev);
706		list_del(&priv->list);
707		kfree(priv);
708		urb->hcpriv = NULL;
709
710		spin_unlock_irqrestore(&vdev->priv_lock, flags2);
711
712		/*
713		 * If tcp connection is alive, we have sent CMD_UNLINK.
714		 * vhci_rx will receive RET_UNLINK and give back the URB.
715		 * Otherwise, we give back it here.
716		 */
717		pr_info("gives back urb %p\n", urb);
718
719		usb_hcd_unlink_urb_from_ep(hcd, urb);
720
721		spin_unlock_irqrestore(&the_controller->lock, flags);
722		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
723				     urb->status);
724		spin_lock_irqsave(&the_controller->lock, flags);
725
726	} else {
727		/* tcp connection is alive */
728		unsigned long flags2;
729		struct vhci_unlink *unlink;
730
731		spin_lock_irqsave(&vdev->priv_lock, flags2);
732
733		/* setup CMD_UNLINK pdu */
734		unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
735		if (!unlink) {
736			pr_err("malloc vhci_unlink\n");
737			spin_unlock_irqrestore(&vdev->priv_lock, flags2);
738			spin_unlock_irqrestore(&the_controller->lock, flags);
739			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
740			return -ENOMEM;
741		}
742
743		unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
744		if (unlink->seqnum == 0xffff)
745			pr_info("seqnum max\n");
746
747		unlink->unlink_seqnum = priv->seqnum;
748
749		pr_info("device %p seems to be still connected\n", vdev);
750
751		/* send cmd_unlink and try to cancel the pending URB in the
752		 * peer */
753		list_add_tail(&unlink->list, &vdev->unlink_tx);
754		wake_up(&vdev->waitq_tx);
755
756		spin_unlock_irqrestore(&vdev->priv_lock, flags2);
757	}
758
759	spin_unlock_irqrestore(&the_controller->lock, flags);
760
761	usbip_dbg_vhci_hc("leave\n");
762	return 0;
763}
764
765static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
766{
767	struct vhci_unlink *unlink, *tmp;
768
769	spin_lock(&vdev->priv_lock);
770
771	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
772		pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
773		list_del(&unlink->list);
774		kfree(unlink);
775	}
776
777	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
778		struct urb *urb;
779
780		/* give back URB of unanswered unlink request */
781		pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
782
783		urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
784		if (!urb) {
785			pr_info("the urb (seqnum %lu) was already given back\n",
786				unlink->unlink_seqnum);
787			list_del(&unlink->list);
788			kfree(unlink);
789			continue;
790		}
791
792		urb->status = -ENODEV;
793
794		spin_lock(&the_controller->lock);
795		usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
796		spin_unlock(&the_controller->lock);
797
798		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
799				     urb->status);
800
801		list_del(&unlink->list);
802		kfree(unlink);
803	}
804
805	spin_unlock(&vdev->priv_lock);
806}
807
808/*
809 * The important thing is that only one context begins cleanup.
810 * This is why error handling and cleanup become simple.
811 * We do not want to consider race condition as possible.
812 */
813static void vhci_shutdown_connection(struct usbip_device *ud)
814{
815	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
816
817	/* need this? see stub_dev.c */
818	if (ud->tcp_socket) {
819		pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
820		kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
821	}
822
823	/* kill threads related to this sdev, if v.c. exists */
824	if (vdev->ud.tcp_rx && !task_is_dead(vdev->ud.tcp_rx))
825		kthread_stop(vdev->ud.tcp_rx);
826	if (vdev->ud.tcp_tx && !task_is_dead(vdev->ud.tcp_tx))
827		kthread_stop(vdev->ud.tcp_tx);
828
829	pr_info("stop threads\n");
830
831	/* active connection is closed */
832	if (vdev->ud.tcp_socket != NULL) {
833		sock_release(vdev->ud.tcp_socket);
834		vdev->ud.tcp_socket = NULL;
835	}
836	pr_info("release socket\n");
837
838	vhci_device_unlink_cleanup(vdev);
839
840	/*
841	 * rh_port_disconnect() is a trigger of ...
842	 *   usb_disable_device():
843	 *	disable all the endpoints for a USB device.
844	 *   usb_disable_endpoint():
845	 *	disable endpoints. pending urbs are unlinked(dequeued).
846	 *
847	 * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
848	 * deteched device should release used urbs in a cleanup function(i.e.
849	 * xxx_disconnect()). Therefore, vhci_hcd does not need to release
850	 * pushed urbs and their private data in this function.
851	 *
852	 * NOTE: vhci_dequeue() must be considered carefully. When shutdowning
853	 * a connection, vhci_shutdown_connection() expects vhci_dequeue()
854	 * gives back pushed urbs and frees their private data by request of
855	 * the cleanup function of a USB driver. When unlinking a urb with an
856	 * active connection, vhci_dequeue() does not give back the urb which
857	 * is actually given back by vhci_rx after receiving its return pdu.
858	 *
859	 */
860	rh_port_disconnect(vdev->rhport);
861
862	pr_info("disconnect device\n");
863}
864
865
866static void vhci_device_reset(struct usbip_device *ud)
867{
868	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
869
870	spin_lock(&ud->lock);
871
872	vdev->speed  = 0;
873	vdev->devid  = 0;
874
875	if (vdev->udev)
876		usb_put_dev(vdev->udev);
877	vdev->udev = NULL;
878
879	ud->tcp_socket = NULL;
880	ud->status = VDEV_ST_NULL;
881
882	spin_unlock(&ud->lock);
883}
884
885static void vhci_device_unusable(struct usbip_device *ud)
886{
887	spin_lock(&ud->lock);
888	ud->status = VDEV_ST_ERROR;
889	spin_unlock(&ud->lock);
890}
891
892static void vhci_device_init(struct vhci_device *vdev)
893{
894	memset(vdev, 0, sizeof(*vdev));
895
896	vdev->ud.side   = USBIP_VHCI;
897	vdev->ud.status = VDEV_ST_NULL;
898	spin_lock_init(&vdev->ud.lock);
899
900	INIT_LIST_HEAD(&vdev->priv_rx);
901	INIT_LIST_HEAD(&vdev->priv_tx);
902	INIT_LIST_HEAD(&vdev->unlink_tx);
903	INIT_LIST_HEAD(&vdev->unlink_rx);
904	spin_lock_init(&vdev->priv_lock);
905
906	init_waitqueue_head(&vdev->waitq_tx);
907
908	vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
909	vdev->ud.eh_ops.reset = vhci_device_reset;
910	vdev->ud.eh_ops.unusable = vhci_device_unusable;
911
912	usbip_start_eh(&vdev->ud);
913}
914
915static int vhci_start(struct usb_hcd *hcd)
916{
917	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
918	int rhport;
919	int err = 0;
920
921	usbip_dbg_vhci_hc("enter vhci_start\n");
922
923	/* initialize private data of usb_hcd */
924
925	for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
926		struct vhci_device *vdev = &vhci->vdev[rhport];
927		vhci_device_init(vdev);
928		vdev->rhport = rhport;
929	}
930
931	atomic_set(&vhci->seqnum, 0);
932	spin_lock_init(&vhci->lock);
933
934	hcd->power_budget = 0; /* no limit */
935	hcd->state  = HC_STATE_RUNNING;
936	hcd->uses_new_polling = 1;
937
938	/* vhci_hcd is now ready to be controlled through sysfs */
939	err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
940	if (err) {
941		pr_err("create sysfs files\n");
942		return err;
943	}
944
945	return 0;
946}
947
948static void vhci_stop(struct usb_hcd *hcd)
949{
950	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
951	int rhport = 0;
952
953	usbip_dbg_vhci_hc("stop VHCI controller\n");
954
955	/* 1. remove the userland interface of vhci_hcd */
956	sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
957
958	/* 2. shutdown all the ports of vhci_hcd */
959	for (rhport = 0 ; rhport < VHCI_NPORTS; rhport++) {
960		struct vhci_device *vdev = &vhci->vdev[rhport];
961
962		usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
963		usbip_stop_eh(&vdev->ud);
964	}
965}
966
967static int vhci_get_frame_number(struct usb_hcd *hcd)
968{
969	pr_err("Not yet implemented\n");
970	return 0;
971}
972
973#ifdef CONFIG_PM
974
975/* FIXME: suspend/resume */
976static int vhci_bus_suspend(struct usb_hcd *hcd)
977{
978	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
979
980	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
981
982	spin_lock_irq(&vhci->lock);
983	/* vhci->rh_state = DUMMY_RH_SUSPENDED;
984	 * set_link_state(vhci); */
985	hcd->state = HC_STATE_SUSPENDED;
986	spin_unlock_irq(&vhci->lock);
987
988	return 0;
989}
990
991static int vhci_bus_resume(struct usb_hcd *hcd)
992{
993	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
994	int rc = 0;
995
996	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
997
998	spin_lock_irq(&vhci->lock);
999	if (!HCD_HW_ACCESSIBLE(hcd)) {
1000		rc = -ESHUTDOWN;
1001	} else {
1002		/* vhci->rh_state = DUMMY_RH_RUNNING;
1003		 * set_link_state(vhci);
1004		 * if (!list_empty(&vhci->urbp_list))
1005		 *	mod_timer(&vhci->timer, jiffies); */
1006		hcd->state = HC_STATE_RUNNING;
1007	}
1008	spin_unlock_irq(&vhci->lock);
1009
1010	return rc;
1011}
1012
1013#else
1014
1015#define vhci_bus_suspend      NULL
1016#define vhci_bus_resume       NULL
1017#endif
1018
1019static struct hc_driver vhci_hc_driver = {
1020	.description	= driver_name,
1021	.product_desc	= driver_desc,
1022	.hcd_priv_size	= sizeof(struct vhci_hcd),
1023
1024	.flags		= HCD_USB2,
1025
1026	.start		= vhci_start,
1027	.stop		= vhci_stop,
1028
1029	.urb_enqueue	= vhci_urb_enqueue,
1030	.urb_dequeue	= vhci_urb_dequeue,
1031
1032	.get_frame_number = vhci_get_frame_number,
1033
1034	.hub_status_data = vhci_hub_status,
1035	.hub_control    = vhci_hub_control,
1036	.bus_suspend	= vhci_bus_suspend,
1037	.bus_resume	= vhci_bus_resume,
1038};
1039
1040static int vhci_hcd_probe(struct platform_device *pdev)
1041{
1042	struct usb_hcd		*hcd;
1043	int			ret;
1044
1045	usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1046
1047	/* will be removed */
1048	if (pdev->dev.dma_mask) {
1049		dev_info(&pdev->dev, "vhci_hcd DMA not supported\n");
1050		return -EINVAL;
1051	}
1052
1053	/*
1054	 * Allocate and initialize hcd.
1055	 * Our private data is also allocated automatically.
1056	 */
1057	hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1058	if (!hcd) {
1059		pr_err("create hcd failed\n");
1060		return -ENOMEM;
1061	}
1062	hcd->has_tt = 1;
1063
1064	/* this is private data for vhci_hcd */
1065	the_controller = hcd_to_vhci(hcd);
1066
1067	/*
1068	 * Finish generic HCD structure initialization and register.
1069	 * Call the driver's reset() and start() routines.
1070	 */
1071	ret = usb_add_hcd(hcd, 0, 0);
1072	if (ret != 0) {
1073		pr_err("usb_add_hcd failed %d\n", ret);
1074		usb_put_hcd(hcd);
1075		the_controller = NULL;
1076		return ret;
1077	}
1078
1079	usbip_dbg_vhci_hc("bye\n");
1080	return 0;
1081}
1082
1083static int vhci_hcd_remove(struct platform_device *pdev)
1084{
1085	struct usb_hcd	*hcd;
1086
1087	hcd = platform_get_drvdata(pdev);
1088	if (!hcd)
1089		return 0;
1090
1091	/*
1092	 * Disconnects the root hub,
1093	 * then reverses the effects of usb_add_hcd(),
1094	 * invoking the HCD's stop() methods.
1095	 */
1096	usb_remove_hcd(hcd);
1097	usb_put_hcd(hcd);
1098	the_controller = NULL;
1099
1100	return 0;
1101}
1102
1103#ifdef CONFIG_PM
1104
1105/* what should happen for USB/IP under suspend/resume? */
1106static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1107{
1108	struct usb_hcd *hcd;
1109	int rhport = 0;
1110	int connected = 0;
1111	int ret = 0;
1112
1113	hcd = platform_get_drvdata(pdev);
1114
1115	spin_lock(&the_controller->lock);
1116
1117	for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1118		if (the_controller->port_status[rhport] &
1119		    USB_PORT_STAT_CONNECTION)
1120			connected += 1;
1121
1122	spin_unlock(&the_controller->lock);
1123
1124	if (connected > 0) {
1125		dev_info(&pdev->dev, "We have %d active connection%s. Do not "
1126			 "suspend.\n", connected, (connected == 1 ? "" : "s"));
1127		ret =  -EBUSY;
1128	} else {
1129		dev_info(&pdev->dev, "suspend vhci_hcd");
1130		clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1131	}
1132
1133	return ret;
1134}
1135
1136static int vhci_hcd_resume(struct platform_device *pdev)
1137{
1138	struct usb_hcd *hcd;
1139
1140	dev_dbg(&pdev->dev, "%s\n", __func__);
1141
1142	hcd = platform_get_drvdata(pdev);
1143	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1144	usb_hcd_poll_rh_status(hcd);
1145
1146	return 0;
1147}
1148
1149#else
1150
1151#define vhci_hcd_suspend	NULL
1152#define vhci_hcd_resume		NULL
1153
1154#endif
1155
1156static struct platform_driver vhci_driver = {
1157	.probe	= vhci_hcd_probe,
1158	.remove	= __devexit_p(vhci_hcd_remove),
1159	.suspend = vhci_hcd_suspend,
1160	.resume	= vhci_hcd_resume,
1161	.driver	= {
1162		.name = (char *) driver_name,
1163		.owner = THIS_MODULE,
1164	},
1165};
1166
1167/*
1168 * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1169 * We need to add this virtual device as a platform device arbitrarily:
1170 *	1. platform_device_register()
1171 */
1172static void the_pdev_release(struct device *dev)
1173{
1174	return;
1175}
1176
1177static struct platform_device the_pdev = {
1178	/* should be the same name as driver_name */
1179	.name = (char *) driver_name,
1180	.id = -1,
1181	.dev = {
1182		/* .driver = &vhci_driver, */
1183		.release = the_pdev_release,
1184	},
1185};
1186
1187static int __init vhci_hcd_init(void)
1188{
1189	int ret;
1190
1191	if (usb_disabled())
1192		return -ENODEV;
1193
1194	ret = platform_driver_register(&vhci_driver);
1195	if (ret < 0)
1196		goto err_driver_register;
1197
1198	ret = platform_device_register(&the_pdev);
1199	if (ret < 0)
1200		goto err_platform_device_register;
1201
1202	pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1203	return ret;
1204
1205err_platform_device_register:
1206	platform_driver_unregister(&vhci_driver);
1207err_driver_register:
1208	return ret;
1209}
1210
1211static void __exit vhci_hcd_exit(void)
1212{
1213	platform_device_unregister(&the_pdev);
1214	platform_driver_unregister(&vhci_driver);
1215}
1216
1217module_init(vhci_hcd_init);
1218module_exit(vhci_hcd_exit);
1219
1220MODULE_AUTHOR(DRIVER_AUTHOR);
1221MODULE_DESCRIPTION(DRIVER_DESC);
1222MODULE_LICENSE("GPL");
1223MODULE_VERSION(USBIP_VERSION);
1224