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 
45 static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
46 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
47 			    u16 wIndex, char *buff, u16 wLength);
48 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
49 			    gfp_t mem_flags);
50 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
51 static int vhci_start(struct usb_hcd *vhci_hcd);
52 static void vhci_stop(struct usb_hcd *hcd);
53 static int vhci_get_frame_number(struct usb_hcd *hcd);
54 
55 static const char driver_name[] = "vhci_hcd";
56 static const char driver_desc[] = "USB/IP Virtual Host Controller";
57 
58 struct vhci_hcd *the_controller;
59 
60 static 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 
dump_port_status_diff(u32 prev_status,u32 new_status)95 static 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 
rh_port_connect(int rhport,enum usb_device_speed speed)121 void 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 
rh_port_disconnect(int rhport)152 void 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  */
vhci_hub_status(struct usb_hcd * hcd,char * buf)201 static 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 
243 done:
244 	spin_unlock_irqrestore(&vhci->lock, flags);
245 	return retval;
246 }
247 
248 /* See hub_configure in hub.c */
hub_descriptor(struct usb_hub_descriptor * desc)249 static 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 
vhci_hub_control(struct usb_hcd * hcd,u16 typeReq,u16 wValue,u16 wIndex,char * buf,u16 wLength)261 static 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 
get_vdev(struct usb_device * udev)454 static 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 
vhci_tx_urb(struct urb * urb)468 static 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 
vhci_urb_enqueue(struct usb_hcd * hcd,struct urb * urb,gfp_t mem_flags)506 static 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 
609 out:
610 	vhci_tx_urb(urb);
611 	spin_unlock_irqrestore(&the_controller->lock, flags);
612 
613 	return 0;
614 
615 no_need_xmit:
616 	usb_hcd_unlink_urb_from_ep(hcd, urb);
617 no_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  */
vhci_urb_dequeue(struct usb_hcd * hcd,struct urb * urb,int status)669 static 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 
vhci_device_unlink_cleanup(struct vhci_device * vdev)765 static 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  */
vhci_shutdown_connection(struct usbip_device * ud)813 static 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 
vhci_device_reset(struct usbip_device * ud)866 static 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 
vhci_device_unusable(struct usbip_device * ud)885 static 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 
vhci_device_init(struct vhci_device * vdev)892 static 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 
vhci_start(struct usb_hcd * hcd)915 static 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 
vhci_stop(struct usb_hcd * hcd)948 static 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 
vhci_get_frame_number(struct usb_hcd * hcd)967 static 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 */
vhci_bus_suspend(struct usb_hcd * hcd)976 static 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 
vhci_bus_resume(struct usb_hcd * hcd)991 static 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 
1019 static 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 
vhci_hcd_probe(struct platform_device * pdev)1040 static 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 
vhci_hcd_remove(struct platform_device * pdev)1083 static 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? */
vhci_hcd_suspend(struct platform_device * pdev,pm_message_t state)1106 static 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 
vhci_hcd_resume(struct platform_device * pdev)1136 static 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 
1156 static 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  */
the_pdev_release(struct device * dev)1172 static void the_pdev_release(struct device *dev)
1173 {
1174 	return;
1175 }
1176 
1177 static 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 
vhci_hcd_init(void)1187 static 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 
1205 err_platform_device_register:
1206 	platform_driver_unregister(&vhci_driver);
1207 err_driver_register:
1208 	return ret;
1209 }
1210 
vhci_hcd_exit(void)1211 static void __exit vhci_hcd_exit(void)
1212 {
1213 	platform_device_unregister(&the_pdev);
1214 	platform_driver_unregister(&vhci_driver);
1215 }
1216 
1217 module_init(vhci_hcd_init);
1218 module_exit(vhci_hcd_exit);
1219 
1220 MODULE_AUTHOR(DRIVER_AUTHOR);
1221 MODULE_DESCRIPTION(DRIVER_DESC);
1222 MODULE_LICENSE("GPL");
1223 MODULE_VERSION(USBIP_VERSION);
1224