Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
[sfrench/cifs-2.6.git] / drivers / staging / usbip / vhci_hcd.c
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
21 #include "usbip_common.h"
22 #include "vhci.h"
23
24 #define DRIVER_VERSION "1.0"
25 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
26 #define DRIVER_DESC "Virtual Host Controller Interface Driver for USB/IP"
27 #define DRIVER_LICENCE "GPL"
28 MODULE_AUTHOR(DRIVER_AUTHOR);
29 MODULE_DESCRIPTION(DRIVER_DESC);
30 MODULE_LICENSE(DRIVER_LICENCE);
31
32
33
34 /*
35  * TODO
36  *      - update root hub emulation
37  *      - move the emulation code to userland ?
38  *              porting to other operating systems
39  *              minimize kernel code
40  *      - add suspend/resume code
41  *      - clean up everything
42  */
43
44
45 /* See usb gadget dummy hcd */
46
47
48 static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
49 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
50                 u16 wIndex, char *buff, u16 wLength);
51 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
52                                                         gfp_t mem_flags);
53 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
54 static int vhci_start(struct usb_hcd *vhci_hcd);
55 static void vhci_stop(struct usb_hcd *hcd);
56 static int vhci_get_frame_number(struct usb_hcd *hcd);
57
58 static const char driver_name[] = "vhci_hcd";
59 static const char driver_desc[] = "USB/IP Virtual Host Controller";
60
61 struct vhci_hcd *the_controller;
62
63 static const char *bit_desc[] = {
64         "CONNECTION",           /*0*/
65         "ENABLE",               /*1*/
66         "SUSPEND",              /*2*/
67         "OVER_CURRENT",         /*3*/
68         "RESET",                /*4*/
69         "R5",           /*5*/
70         "R6",           /*6*/
71         "R7",           /*7*/
72         "POWER",                /*8*/
73         "LOWSPEED",             /*9*/
74         "HIGHSPEED",            /*10*/
75         "PORT_TEST",            /*11*/
76         "INDICATOR",            /*12*/
77         "R13",          /*13*/
78         "R14",          /*14*/
79         "R15",          /*15*/
80         "C_CONNECTION",         /*16*/
81         "C_ENABLE",             /*17*/
82         "C_SUSPEND",            /*18*/
83         "C_OVER_CURRENT",       /*19*/
84         "C_RESET",              /*20*/
85         "R21",          /*21*/
86         "R22",          /*22*/
87         "R23",          /*23*/
88         "R24",          /*24*/
89         "R25",          /*25*/
90         "R26",          /*26*/
91         "R27",          /*27*/
92         "R28",          /*28*/
93         "R29",          /*29*/
94         "R30",          /*30*/
95         "R31",          /*31*/
96 };
97
98
99 static void dump_port_status(u32 status)
100 {
101         int i = 0;
102
103         printk(KERN_DEBUG "status %08x:", status);
104         for (i = 0; i < 32; i++) {
105                 if (status & (1 << i))
106                         printk(" %s", bit_desc[i]);
107         }
108
109         printk("\n");
110 }
111
112
113
114 void rh_port_connect(int rhport, enum usb_device_speed speed)
115 {
116         unsigned long   flags;
117
118         usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
119
120         spin_lock_irqsave(&the_controller->lock, flags);
121
122         the_controller->port_status[rhport] |= USB_PORT_STAT_CONNECTION
123                 | (1 << USB_PORT_FEAT_C_CONNECTION);
124
125         switch (speed) {
126         case USB_SPEED_HIGH:
127                 the_controller->port_status[rhport] |= USB_PORT_STAT_HIGH_SPEED;
128                 break;
129         case USB_SPEED_LOW:
130                 the_controller->port_status[rhport] |= USB_PORT_STAT_LOW_SPEED;
131                 break;
132         default:
133                 break;
134         }
135
136         /* spin_lock(&the_controller->vdev[rhport].ud.lock);
137          * the_controller->vdev[rhport].ud.status = VDEV_CONNECT;
138          * spin_unlock(&the_controller->vdev[rhport].ud.lock); */
139
140         the_controller->pending_port = rhport;
141
142         spin_unlock_irqrestore(&the_controller->lock, flags);
143
144         usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
145 }
146
147 void rh_port_disconnect(int rhport)
148 {
149         unsigned long flags;
150
151         usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
152
153         spin_lock_irqsave(&the_controller->lock, flags);
154         /* stop_activity(dum, driver); */
155         the_controller->port_status[rhport] &= ~USB_PORT_STAT_CONNECTION;
156         the_controller->port_status[rhport] |=
157                                         (1 << USB_PORT_FEAT_C_CONNECTION);
158
159
160         /* not yet complete the disconnection
161          * spin_lock(&vdev->ud.lock);
162          * vdev->ud.status = VHC_ST_DISCONNECT;
163          * spin_unlock(&vdev->ud.lock); */
164
165         spin_unlock_irqrestore(&the_controller->lock, flags);
166 }
167
168
169
170 /*----------------------------------------------------------------------*/
171
172 #define PORT_C_MASK \
173         ((USB_PORT_STAT_C_CONNECTION \
174           | USB_PORT_STAT_C_ENABLE \
175           | USB_PORT_STAT_C_SUSPEND \
176           | USB_PORT_STAT_C_OVERCURRENT \
177           | USB_PORT_STAT_C_RESET) << 16)
178
179 /*
180  * This function is almostly the same as dummy_hcd.c:dummy_hub_status() without
181  * suspend/resume support. But, it is modified to provide multiple ports.
182  *
183  * @buf: a bitmap to show which port status has been changed.
184  *  bit  0: reserved or used for another purpose?
185  *  bit  1: the status of port 0 has been changed.
186  *  bit  2: the status of port 1 has been changed.
187  *  ...
188  *  bit  7: the status of port 6 has been changed.
189  *  bit  8: the status of port 7 has been changed.
190  *  ...
191  *  bit 15: the status of port 14 has been changed.
192  *
193  * So, the maximum number of ports is 31 ( port 0 to port 30) ?
194  *
195  * The return value is the actual transfered length in byte. If nothing has
196  * been changed, return 0. In the case that the number of ports is less than or
197  * equal to 6 (VHCI_NPORTS==7), return 1.
198  *
199  */
200 static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
201 {
202         struct vhci_hcd *vhci;
203         unsigned long   flags;
204         int             retval = 0;
205
206         /* the enough buffer is allocated according to USB_MAXCHILDREN */
207         unsigned long   *event_bits = (unsigned long *) buf;
208         int             rhport;
209         int             changed = 0;
210
211
212         *event_bits = 0;
213
214         vhci = hcd_to_vhci(hcd);
215
216         spin_lock_irqsave(&vhci->lock, flags);
217         if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
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         usbip_uinfo("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 */
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->bitmap[0] = 0xff;
258         desc->bitmap[1] = 0xff;
259 }
260
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 (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
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                 printk(KERN_ERR "%s: invalid port number %d\n", __func__,
282                                                                 wIndex);
283         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
284
285         dum = hcd_to_vhci(hcd);
286
287         spin_lock_irqsave(&dum->lock, flags);
288
289         /* store old status and compare now and old later */
290         if (usbip_dbg_flag_vhci_rh) {
291                 int i = 0;
292                 for (i = 0; i < VHCI_NPORTS; i++)
293                         prev_port_status[i] = dum->port_status[i];
294         }
295
296         switch (typeReq) {
297         case ClearHubFeature:
298                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
299                 break;
300         case ClearPortFeature:
301                 switch (wValue) {
302                 case USB_PORT_FEAT_SUSPEND:
303                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
304                                 /* 20msec signaling */
305                                 dum->resuming = 1;
306                                 dum->re_timeout =
307                                         jiffies + msecs_to_jiffies(20);
308                         }
309                         break;
310                 case USB_PORT_FEAT_POWER:
311                         usbip_dbg_vhci_rh(" ClearPortFeature: "
312                                                 "USB_PORT_FEAT_POWER\n");
313                         dum->port_status[rhport] = 0;
314                         /* dum->address = 0; */
315                         /* dum->hdev = 0; */
316                         dum->resuming = 0;
317                         break;
318                 case USB_PORT_FEAT_C_RESET:
319                         usbip_dbg_vhci_rh(" ClearPortFeature: "
320                                                 "USB_PORT_FEAT_C_RESET\n");
321                         switch (dum->vdev[rhport].speed) {
322                         case USB_SPEED_HIGH:
323                                 dum->port_status[rhport] |=
324                                                 USB_PORT_STAT_HIGH_SPEED;
325                                 break;
326                         case USB_SPEED_LOW:
327                                 dum->port_status[rhport] |=
328                                                 USB_PORT_STAT_LOW_SPEED;
329                                 break;
330                         default:
331                                 break;
332                         }
333                 default:
334                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
335                                                                 wValue);
336                         dum->port_status[rhport] &= ~(1 << wValue);
337                 }
338                 break;
339         case GetHubDescriptor:
340                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
341                 hub_descriptor((struct usb_hub_descriptor *) buf);
342                 break;
343         case GetHubStatus:
344                 usbip_dbg_vhci_rh(" GetHubStatus\n");
345                 *(__le32 *) buf = __constant_cpu_to_le32(0);
346                 break;
347         case GetPortStatus:
348                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
349                 if (wIndex > VHCI_NPORTS || wIndex < 1) {
350                         printk(KERN_ERR "%s: invalid port number %d\n",
351                                __func__, wIndex);
352                         retval = -EPIPE;
353                 }
354
355                 /* we do no care of resume. */
356
357                 /* whoever resets or resumes must GetPortStatus to
358                  * complete it!!
359                  *                                   */
360                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
361                         printk(KERN_ERR "%s: not yet\n", __func__);
362                         dum->port_status[rhport] |=
363                                         (1 << USB_PORT_FEAT_C_SUSPEND);
364                         dum->port_status[rhport] &=
365                                         ~(1 << USB_PORT_FEAT_SUSPEND);
366                         dum->resuming = 0;
367                         dum->re_timeout = 0;
368                         /* if (dum->driver && dum->driver->resume) {
369                          *      spin_unlock (&dum->lock);
370                          *      dum->driver->resume (&dum->gadget);
371                          *      spin_lock (&dum->lock);
372                          * } */
373                 }
374
375                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
376                                 0 && time_after(jiffies, dum->re_timeout)) {
377                         dum->port_status[rhport] |=
378                                                 (1 << USB_PORT_FEAT_C_RESET);
379                         dum->port_status[rhport] &=
380                                                 ~(1 << USB_PORT_FEAT_RESET);
381                         dum->re_timeout = 0;
382
383                         if (dum->vdev[rhport].ud.status ==
384                                                         VDEV_ST_NOTASSIGNED) {
385                                 usbip_dbg_vhci_rh(" enable rhport %d "
386                                                 "(status %u)\n",
387                                                 rhport,
388                                                 dum->vdev[rhport].ud.status);
389                                 dum->port_status[rhport] |=
390                                                         USB_PORT_STAT_ENABLE;
391                         }
392 #if 0
393                         if (dum->driver) {
394
395                                 dum->port_status[rhport] |=
396                                                         USB_PORT_STAT_ENABLE;
397                                 /* give it the best speed we agree on */
398                                 dum->gadget.speed = dum->driver->speed;
399                                 dum->gadget.ep0->maxpacket = 64;
400                                 switch (dum->gadget.speed) {
401                                 case USB_SPEED_HIGH:
402                                         dum->port_status[rhport] |=
403                                         USB_PORT_STAT_HIGH_SPEED;
404                                         break;
405                                 case USB_SPEED_LOW:
406                                         dum->gadget.ep0->maxpacket = 8;
407                                         dum->port_status[rhport] |=
408                                         USB_PORT_STAT_LOW_SPEED;
409                                         break;
410                                 default:
411                                         dum->gadget.speed = USB_SPEED_FULL;
412                                         break;
413                                 }
414                         }
415 #endif
416
417                 }
418                 ((u16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
419                 ((u16 *) buf)[1] =
420                                 cpu_to_le16(dum->port_status[rhport] >> 16);
421
422                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
423                                                         ((u16 *)buf)[1]);
424                 break;
425         case SetHubFeature:
426                 usbip_dbg_vhci_rh(" SetHubFeature\n");
427                 retval = -EPIPE;
428                 break;
429         case SetPortFeature:
430                 switch (wValue) {
431                 case USB_PORT_FEAT_SUSPEND:
432                         usbip_dbg_vhci_rh(" SetPortFeature: "
433                                         "USB_PORT_FEAT_SUSPEND\n");
434                         printk(KERN_ERR "%s: not yet\n", __func__);
435 #if 0
436                         dum->port_status[rhport] |=
437                                                 (1 << USB_PORT_FEAT_SUSPEND);
438                         if (dum->driver->suspend) {
439                                 spin_unlock(&dum->lock);
440                                 dum->driver->suspend(&dum->gadget);
441                                 spin_lock(&dum->lock);
442                         }
443 #endif
444                         break;
445                 case USB_PORT_FEAT_RESET:
446                         usbip_dbg_vhci_rh(" SetPortFeature: "
447                                                 "USB_PORT_FEAT_RESET\n");
448                         /* if it's already running, disconnect first */
449                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
450                                 dum->port_status[rhport] &=
451                                                 ~(USB_PORT_STAT_ENABLE |
452                                                   USB_PORT_STAT_LOW_SPEED |
453                                                   USB_PORT_STAT_HIGH_SPEED);
454 #if 0
455                                 if (dum->driver) {
456                                         dev_dbg(hardware, "disconnect\n");
457                                         stop_activity(dum, dum->driver);
458                                 }
459 #endif
460
461                                 /* FIXME test that code path! */
462                         }
463                         /* 50msec reset signaling */
464                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
465
466                         /* FALLTHROUGH */
467                 default:
468                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
469                                                                 wValue);
470                         dum->port_status[rhport] |= (1 << wValue);
471                 }
472                 break;
473
474         default:
475                 printk(KERN_ERR "%s: default: no such request\n", __func__);
476                 /* dev_dbg (hardware,
477                  *              "hub control req%04x v%04x i%04x l%d\n",
478                  *              typeReq, wValue, wIndex, wLength); */
479
480                 /* "protocol stall" on error */
481                 retval = -EPIPE;
482         }
483
484         if (usbip_dbg_flag_vhci_rh) {
485                 printk(KERN_DEBUG "port %d\n", rhport);
486                 dump_port_status(prev_port_status[rhport]);
487                 dump_port_status(dum->port_status[rhport]);
488         }
489         usbip_dbg_vhci_rh(" bye\n");
490
491         spin_unlock_irqrestore(&dum->lock, flags);
492
493         return retval;
494 }
495
496
497
498 /*----------------------------------------------------------------------*/
499
500 static struct vhci_device *get_vdev(struct usb_device *udev)
501 {
502         int i;
503
504         if (!udev)
505                 return NULL;
506
507         for (i = 0; i < VHCI_NPORTS; i++)
508                 if (the_controller->vdev[i].udev == udev)
509                         return port_to_vdev(i);
510
511         return NULL;
512 }
513
514 static void vhci_tx_urb(struct urb *urb)
515 {
516         struct vhci_device *vdev = get_vdev(urb->dev);
517         struct vhci_priv *priv;
518         unsigned long flag;
519
520         if (!vdev) {
521                 err("could not get virtual device");
522                 /* BUG(); */
523                 return;
524         }
525
526         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
527
528         spin_lock_irqsave(&vdev->priv_lock, flag);
529
530         if (!priv) {
531                 dev_err(&urb->dev->dev, "malloc vhci_priv\n");
532                 spin_unlock_irqrestore(&vdev->priv_lock, flag);
533                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
534                 return;
535         }
536
537         priv->seqnum = atomic_inc_return(&the_controller->seqnum);
538         if (priv->seqnum == 0xffff)
539                 usbip_uinfo("seqnum max\n");
540
541         priv->vdev = vdev;
542         priv->urb = urb;
543
544         urb->hcpriv = (void *) priv;
545
546
547         list_add_tail(&priv->list, &vdev->priv_tx);
548
549         wake_up(&vdev->waitq_tx);
550         spin_unlock_irqrestore(&vdev->priv_lock, flag);
551 }
552
553 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
554                             gfp_t mem_flags)
555 {
556         struct device *dev = &urb->dev->dev;
557         int ret = 0;
558         unsigned long flags;
559
560         usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
561                     hcd, urb, mem_flags);
562
563         /* patch to usb_sg_init() is in 2.5.60 */
564         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
565
566         spin_lock_irqsave(&the_controller->lock, flags);
567
568         if (urb->status != -EINPROGRESS) {
569                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
570                 spin_unlock_irqrestore(&the_controller->lock, flags);
571                 return urb->status;
572         }
573
574         ret = usb_hcd_link_urb_to_ep(hcd, urb);
575         if (ret)
576                 goto no_need_unlink;
577
578         /*
579          * The enumeration process is as follows;
580          *
581          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
582          *     to get max packet length of default pipe
583          *
584          *  2. Set_Address request to DevAddr(0) EndPoint(0)
585          *
586          */
587
588         if (usb_pipedevice(urb->pipe) == 0) {
589                 __u8 type = usb_pipetype(urb->pipe);
590                 struct usb_ctrlrequest *ctrlreq =
591                                 (struct usb_ctrlrequest *) urb->setup_packet;
592                 struct vhci_device *vdev =
593                                 port_to_vdev(the_controller->pending_port);
594
595                 if (type != PIPE_CONTROL || !ctrlreq) {
596                         dev_err(dev, "invalid request to devnum 0\n");
597                         ret = -EINVAL;
598                         goto no_need_xmit;
599                 }
600
601                 switch (ctrlreq->bRequest) {
602                 case USB_REQ_SET_ADDRESS:
603                         /* set_address may come when a device is reset */
604                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
605                                  ctrlreq->wValue, vdev->rhport);
606
607                         vdev->udev = urb->dev;
608
609                         spin_lock(&vdev->ud.lock);
610                         vdev->ud.status = VDEV_ST_USED;
611                         spin_unlock(&vdev->ud.lock);
612
613                         if (urb->status == -EINPROGRESS) {
614                                 /* This request is successfully completed. */
615                                 /* If not -EINPROGRESS, possibly unlinked. */
616                                 urb->status = 0;
617                         }
618
619                         goto no_need_xmit;
620
621                 case USB_REQ_GET_DESCRIPTOR:
622                         if (ctrlreq->wValue == (USB_DT_DEVICE << 8))
623                                 usbip_dbg_vhci_hc("Not yet?: "
624                                                 "Get_Descriptor to device 0 "
625                                                 "(get max pipe size)\n");
626
627                         /* FIXME: reference count? (usb_get_dev()) */
628                         vdev->udev = urb->dev;
629                         goto out;
630
631                 default:
632                         /* NOT REACHED */
633                         dev_err(dev, "invalid request to devnum 0 bRequest %u, "
634                                 "wValue %u\n", ctrlreq->bRequest,
635                                 ctrlreq->wValue);
636                         ret =  -EINVAL;
637                         goto no_need_xmit;
638                 }
639
640         }
641
642 out:
643         vhci_tx_urb(urb);
644
645         spin_unlock_irqrestore(&the_controller->lock, flags);
646
647         return 0;
648
649 no_need_xmit:
650         usb_hcd_unlink_urb_from_ep(hcd, urb);
651 no_need_unlink:
652         spin_unlock_irqrestore(&the_controller->lock, flags);
653
654         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
655
656         return ret;
657 }
658
659 /*
660  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
661  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
662  * back its urb. For the driver unlinking the urb, the content of the urb is
663  * not important, but the calling to its completion handler is important; the
664  * completion of unlinking is notified by the completion handler.
665  *
666  *
667  * CLIENT SIDE
668  *
669  * - When vhci_hcd receives RET_SUBMIT,
670  *
671  *      - case 1a). the urb of the pdu is not unlinking.
672  *              - normal case
673  *              => just give back the urb
674  *
675  *      - case 1b). the urb of the pdu is unlinking.
676  *              - usbip.ko will return a reply of the unlinking request.
677  *              => give back the urb now and go to case 2b).
678  *
679  * - When vhci_hcd receives RET_UNLINK,
680  *
681  *      - case 2a). a submit request is still pending in vhci_hcd.
682  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
683  *                completed there.
684  *              => free a pending submit request
685  *              => notify unlink completeness by giving back the urb
686  *
687  *      - case 2b). a submit request is *not* pending in vhci_hcd.
688  *              - urb was already given back to the core driver.
689  *              => do not give back the urb
690  *
691  *
692  * SERVER SIDE
693  *
694  * - When usbip receives CMD_UNLINK,
695  *
696  *      - case 3a). the urb of the unlink request is now in submission.
697  *              => do usb_unlink_urb().
698  *              => after the unlink is completed, send RET_UNLINK.
699  *
700  *      - case 3b). the urb of the unlink request is not in submission.
701  *              - may be already completed or never be received
702  *              => send RET_UNLINK
703  *
704  */
705 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
706 {
707         unsigned long flags;
708         struct vhci_priv *priv;
709         struct vhci_device *vdev;
710
711         usbip_uinfo("vhci_hcd: dequeue a urb %p\n", urb);
712
713
714         spin_lock_irqsave(&the_controller->lock, flags);
715
716         priv = urb->hcpriv;
717         if (!priv) {
718                 /* URB was never linked! or will be soon given back by
719                  * vhci_rx. */
720                 spin_unlock_irqrestore(&the_controller->lock, flags);
721                 return 0;
722         }
723
724         {
725                 int ret = 0;
726                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
727                 if (ret) {
728                         spin_unlock_irqrestore(&the_controller->lock, flags);
729                         return ret;
730                 }
731         }
732
733          /* send unlink request here? */
734         vdev = priv->vdev;
735
736         if (!vdev->ud.tcp_socket) {
737                 /* tcp connection is closed */
738                 unsigned long flags2;
739
740                 spin_lock_irqsave(&vdev->priv_lock, flags2);
741
742                 usbip_uinfo("vhci_hcd: device %p seems to be disconnected\n",
743                                                                         vdev);
744                 list_del(&priv->list);
745                 kfree(priv);
746                 urb->hcpriv = NULL;
747
748                 spin_unlock_irqrestore(&vdev->priv_lock, flags2);
749
750                 /*
751                  * If tcp connection is alive, we have sent CMD_UNLINK.
752                  * vhci_rx will receive RET_UNLINK and give back the URB.
753                  * Otherwise, we give back it here.
754                  */
755                 usbip_uinfo("vhci_hcd: vhci_urb_dequeue() gives back urb %p\n",
756                                                                         urb);
757
758                 usb_hcd_unlink_urb_from_ep(hcd, urb);
759
760                 spin_unlock_irqrestore(&the_controller->lock, flags);
761                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
762                                                                 urb->status);
763                 spin_lock_irqsave(&the_controller->lock, flags);
764
765         } else {
766                 /* tcp connection is alive */
767                 unsigned long flags2;
768                 struct vhci_unlink *unlink;
769
770                 spin_lock_irqsave(&vdev->priv_lock, flags2);
771
772                 /* setup CMD_UNLINK pdu */
773                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
774                 if (!unlink) {
775                         usbip_uerr("malloc vhci_unlink\n");
776                         spin_unlock_irqrestore(&vdev->priv_lock, flags2);
777                         spin_unlock_irqrestore(&the_controller->lock, flags);
778                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
779                         return -ENOMEM;
780                 }
781
782                 unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
783                 if (unlink->seqnum == 0xffff)
784                         usbip_uinfo("seqnum max\n");
785
786                 unlink->unlink_seqnum = priv->seqnum;
787
788                 usbip_uinfo("vhci_hcd: device %p seems to be still connected\n",
789                                                                         vdev);
790
791                 /* send cmd_unlink and try to cancel the pending URB in the
792                  * peer */
793                 list_add_tail(&unlink->list, &vdev->unlink_tx);
794                 wake_up(&vdev->waitq_tx);
795
796                 spin_unlock_irqrestore(&vdev->priv_lock, flags2);
797         }
798
799
800         if (!vdev->ud.tcp_socket) {
801                 /* tcp connection is closed */
802                 usbip_uinfo("vhci_hcd: vhci_urb_dequeue() gives back urb %p\n",
803                                                                         urb);
804
805                 usb_hcd_unlink_urb_from_ep(hcd, urb);
806
807                 spin_unlock_irqrestore(&the_controller->lock, flags);
808                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
809                                                                 urb->status);
810                 spin_lock_irqsave(&the_controller->lock, flags);
811         }
812
813         spin_unlock_irqrestore(&the_controller->lock, flags);
814
815         usbip_dbg_vhci_hc("leave\n");
816         return 0;
817 }
818
819
820 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
821 {
822         struct vhci_unlink *unlink, *tmp;
823
824         spin_lock(&vdev->priv_lock);
825
826         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
827                 list_del(&unlink->list);
828                 kfree(unlink);
829         }
830
831         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
832                 list_del(&unlink->list);
833                 kfree(unlink);
834         }
835
836         spin_unlock(&vdev->priv_lock);
837 }
838
839 /*
840  * The important thing is that only one context begins cleanup.
841  * This is why error handling and cleanup become simple.
842  * We do not want to consider race condition as possible.
843  */
844 static void vhci_shutdown_connection(struct usbip_device *ud)
845 {
846         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
847
848         /* need this? see stub_dev.c */
849         if (ud->tcp_socket) {
850                 usbip_udbg("shutdown tcp_socket %p\n", ud->tcp_socket);
851                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
852         }
853
854         usbip_stop_threads(&vdev->ud);
855         usbip_uinfo("stop threads\n");
856
857         /* active connection is closed */
858         if (vdev->ud.tcp_socket != NULL) {
859                 sock_release(vdev->ud.tcp_socket);
860                 vdev->ud.tcp_socket = NULL;
861         }
862         usbip_uinfo("release socket\n");
863
864         vhci_device_unlink_cleanup(vdev);
865
866         /*
867          * rh_port_disconnect() is a trigger of ...
868          *   usb_disable_device():
869          *      disable all the endpoints for a USB device.
870          *   usb_disable_endpoint():
871          *      disable endpoints. pending urbs are unlinked(dequeued).
872          *
873          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
874          * deteched device should release used urbs in a cleanup function(i.e.
875          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
876          * pushed urbs and their private data in this function.
877          *
878          * NOTE: vhci_dequeue() must be considered carefully. When shutdowning
879          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
880          * gives back pushed urbs and frees their private data by request of
881          * the cleanup function of a USB driver. When unlinking a urb with an
882          * active connection, vhci_dequeue() does not give back the urb which
883          * is actually given back by vhci_rx after receiving its return pdu.
884          *
885          */
886         rh_port_disconnect(vdev->rhport);
887
888         usbip_uinfo("disconnect device\n");
889 }
890
891
892 static void vhci_device_reset(struct usbip_device *ud)
893 {
894         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
895
896         spin_lock(&ud->lock);
897
898         vdev->speed  = 0;
899         vdev->devid  = 0;
900
901         ud->tcp_socket = NULL;
902
903         ud->status = VDEV_ST_NULL;
904
905         spin_unlock(&ud->lock);
906 }
907
908 static void vhci_device_unusable(struct usbip_device *ud)
909 {
910         spin_lock(&ud->lock);
911
912         ud->status = VDEV_ST_ERROR;
913
914         spin_unlock(&ud->lock);
915 }
916
917 static void vhci_device_init(struct vhci_device *vdev)
918 {
919         memset(vdev, 0, sizeof(*vdev));
920
921         usbip_task_init(&vdev->ud.tcp_rx, "vhci_rx", vhci_rx_loop);
922         usbip_task_init(&vdev->ud.tcp_tx, "vhci_tx", vhci_tx_loop);
923
924         vdev->ud.side   = USBIP_VHCI;
925         vdev->ud.status = VDEV_ST_NULL;
926         /* vdev->ud.lock   = SPIN_LOCK_UNLOCKED; */
927         spin_lock_init(&vdev->ud.lock);
928
929         INIT_LIST_HEAD(&vdev->priv_rx);
930         INIT_LIST_HEAD(&vdev->priv_tx);
931         INIT_LIST_HEAD(&vdev->unlink_tx);
932         INIT_LIST_HEAD(&vdev->unlink_rx);
933         /* vdev->priv_lock = SPIN_LOCK_UNLOCKED; */
934         spin_lock_init(&vdev->priv_lock);
935
936         init_waitqueue_head(&vdev->waitq_tx);
937
938         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
939         vdev->ud.eh_ops.reset = vhci_device_reset;
940         vdev->ud.eh_ops.unusable = vhci_device_unusable;
941
942         usbip_start_eh(&vdev->ud);
943 }
944
945
946 /*----------------------------------------------------------------------*/
947
948 static int vhci_start(struct usb_hcd *hcd)
949 {
950         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
951         int rhport;
952         int err = 0;
953
954         usbip_dbg_vhci_hc("enter vhci_start\n");
955
956
957         /* initialize private data of usb_hcd */
958
959         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
960                 struct vhci_device *vdev = &vhci->vdev[rhport];
961                 vhci_device_init(vdev);
962                 vdev->rhport = rhport;
963         }
964
965         atomic_set(&vhci->seqnum, 0);
966         spin_lock_init(&vhci->lock);
967
968
969
970         hcd->power_budget = 0; /* no limit */
971         hcd->state  = HC_STATE_RUNNING;
972         hcd->uses_new_polling = 1;
973
974
975         /* vhci_hcd is now ready to be controlled through sysfs */
976         err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
977         if (err) {
978                 usbip_uerr("create sysfs files\n");
979                 return err;
980         }
981
982         return 0;
983 }
984
985 static void vhci_stop(struct usb_hcd *hcd)
986 {
987         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
988         int rhport = 0;
989
990         usbip_dbg_vhci_hc("stop VHCI controller\n");
991
992
993         /* 1. remove the userland interface of vhci_hcd */
994         sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
995
996         /* 2. shutdown all the ports of vhci_hcd */
997         for (rhport = 0 ; rhport < VHCI_NPORTS; rhport++) {
998                 struct vhci_device *vdev = &vhci->vdev[rhport];
999
1000                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
1001                 usbip_stop_eh(&vdev->ud);
1002         }
1003
1004
1005         usbip_uinfo("vhci_stop done\n");
1006 }
1007
1008 /*----------------------------------------------------------------------*/
1009
1010 static int vhci_get_frame_number(struct usb_hcd *hcd)
1011 {
1012         usbip_uerr("Not yet implemented\n");
1013         return 0;
1014 }
1015
1016
1017 #ifdef CONFIG_PM
1018
1019 /* FIXME: suspend/resume */
1020 static int vhci_bus_suspend(struct usb_hcd *hcd)
1021 {
1022         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1023
1024         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1025
1026         spin_lock_irq(&vhci->lock);
1027         /* vhci->rh_state = DUMMY_RH_SUSPENDED;
1028          * set_link_state(vhci); */
1029         hcd->state = HC_STATE_SUSPENDED;
1030         spin_unlock_irq(&vhci->lock);
1031
1032         return 0;
1033 }
1034
1035 static int vhci_bus_resume(struct usb_hcd *hcd)
1036 {
1037         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1038         int rc = 0;
1039
1040         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1041
1042         spin_lock_irq(&vhci->lock);
1043         if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
1044                 rc = -ESHUTDOWN;
1045         } else {
1046                 /* vhci->rh_state = DUMMY_RH_RUNNING;
1047                  * set_link_state(vhci);
1048                  * if (!list_empty(&vhci->urbp_list))
1049                  *      mod_timer(&vhci->timer, jiffies); */
1050                 hcd->state = HC_STATE_RUNNING;
1051         }
1052         spin_unlock_irq(&vhci->lock);
1053         return rc;
1054
1055         return 0;
1056 }
1057
1058 #else
1059
1060 #define vhci_bus_suspend      NULL
1061 #define vhci_bus_resume       NULL
1062 #endif
1063
1064
1065
1066 static struct hc_driver vhci_hc_driver = {
1067         .description    = driver_name,
1068         .product_desc   = driver_desc,
1069         .hcd_priv_size  = sizeof(struct vhci_hcd),
1070
1071         .flags          = HCD_USB2,
1072
1073         .start          = vhci_start,
1074         .stop           = vhci_stop,
1075
1076         .urb_enqueue    = vhci_urb_enqueue,
1077         .urb_dequeue    = vhci_urb_dequeue,
1078
1079         .get_frame_number = vhci_get_frame_number,
1080
1081         .hub_status_data = vhci_hub_status,
1082         .hub_control    = vhci_hub_control,
1083         .bus_suspend    = vhci_bus_suspend,
1084         .bus_resume     = vhci_bus_resume,
1085 };
1086
1087 static int vhci_hcd_probe(struct platform_device *pdev)
1088 {
1089         struct usb_hcd          *hcd;
1090         int                     ret;
1091
1092         usbip_uinfo("proving...\n");
1093
1094         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1095
1096         /* will be removed */
1097         if (pdev->dev.dma_mask) {
1098                 dev_info(&pdev->dev, "vhci_hcd DMA not supported\n");
1099                 return -EINVAL;
1100         }
1101
1102         /*
1103          * Allocate and initialize hcd.
1104          * Our private data is also allocated automatically.
1105          */
1106         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1107         if (!hcd) {
1108                 usbip_uerr("create hcd failed\n");
1109                 return -ENOMEM;
1110         }
1111
1112
1113         /* this is private data for vhci_hcd */
1114         the_controller = hcd_to_vhci(hcd);
1115
1116         /*
1117          * Finish generic HCD structure initialization and register.
1118          * Call the driver's reset() and start() routines.
1119          */
1120         ret = usb_add_hcd(hcd, 0, 0);
1121         if (ret != 0) {
1122                 usbip_uerr("usb_add_hcd failed %d\n", ret);
1123                 usb_put_hcd(hcd);
1124                 the_controller = NULL;
1125                 return ret;
1126         }
1127
1128
1129         usbip_dbg_vhci_hc("bye\n");
1130         return 0;
1131 }
1132
1133
1134 static int vhci_hcd_remove(struct platform_device *pdev)
1135 {
1136         struct usb_hcd  *hcd;
1137
1138         hcd = platform_get_drvdata(pdev);
1139         if (!hcd)
1140                 return 0;
1141
1142         /*
1143          * Disconnects the root hub,
1144          * then reverses the effects of usb_add_hcd(),
1145          * invoking the HCD's stop() methods.
1146          */
1147         usb_remove_hcd(hcd);
1148         usb_put_hcd(hcd);
1149         the_controller = NULL;
1150
1151
1152         return 0;
1153 }
1154
1155
1156
1157 #ifdef CONFIG_PM
1158
1159 /* what should happen for USB/IP under suspend/resume? */
1160 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1161 {
1162         struct usb_hcd *hcd;
1163         int rhport = 0;
1164         int connected = 0;
1165         int ret = 0;
1166
1167         dev_dbg(&pdev->dev, "%s\n", __func__);
1168
1169         hcd = platform_get_drvdata(pdev);
1170
1171         spin_lock(&the_controller->lock);
1172
1173         for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1174                 if (the_controller->port_status[rhport] &
1175                                                 USB_PORT_STAT_CONNECTION)
1176                         connected += 1;
1177
1178         spin_unlock(&the_controller->lock);
1179
1180         if (connected > 0) {
1181                 usbip_uinfo("We have %d active connection%s. Do not suspend.\n",
1182                                 connected, (connected == 1 ? "" : "s"));
1183                 ret =  -EBUSY;
1184         } else {
1185                 usbip_uinfo("suspend vhci_hcd");
1186                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1187         }
1188
1189         return ret;
1190 }
1191
1192 static int vhci_hcd_resume(struct platform_device *pdev)
1193 {
1194         struct usb_hcd *hcd;
1195
1196         dev_dbg(&pdev->dev, "%s\n", __func__);
1197
1198         hcd = platform_get_drvdata(pdev);
1199         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1200         usb_hcd_poll_rh_status(hcd);
1201
1202         return 0;
1203 }
1204
1205 #else
1206
1207 #define vhci_hcd_suspend        NULL
1208 #define vhci_hcd_resume         NULL
1209
1210 #endif
1211
1212
1213 static struct platform_driver vhci_driver = {
1214         .probe  = vhci_hcd_probe,
1215         .remove = __devexit_p(vhci_hcd_remove),
1216         .suspend = vhci_hcd_suspend,
1217         .resume = vhci_hcd_resume,
1218         .driver = {
1219                 .name = (char *) driver_name,
1220                 .owner = THIS_MODULE,
1221         },
1222 };
1223
1224 /*----------------------------------------------------------------------*/
1225
1226 /*
1227  * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1228  * We need to add this virtual device as a platform device arbitrarily:
1229  *      1. platform_device_register()
1230  */
1231 static void the_pdev_release(struct device *dev)
1232 {
1233         return;
1234 }
1235
1236 static struct platform_device the_pdev = {
1237         /* should be the same name as driver_name */
1238         .name = (char *) driver_name,
1239         .id = -1,
1240         .dev = {
1241                 /* .driver = &vhci_driver, */
1242                 .release = the_pdev_release,
1243         },
1244 };
1245
1246 static int __init vhci_init(void)
1247 {
1248         int ret;
1249
1250         usbip_dbg_vhci_hc("enter\n");
1251         if (usb_disabled())
1252                 return -ENODEV;
1253
1254         printk(KERN_INFO KBUILD_MODNAME ": %s, %s\n", driver_name,
1255                DRIVER_VERSION);
1256
1257         ret = platform_driver_register(&vhci_driver);
1258         if (ret < 0)
1259                 goto err_driver_register;
1260
1261         ret = platform_device_register(&the_pdev);
1262         if (ret < 0)
1263                 goto err_platform_device_register;
1264
1265         usbip_dbg_vhci_hc("bye\n");
1266         return ret;
1267
1268         /* error occurred */
1269 err_platform_device_register:
1270         platform_driver_unregister(&vhci_driver);
1271
1272 err_driver_register:
1273         usbip_dbg_vhci_hc("bye\n");
1274         return ret;
1275 }
1276 module_init(vhci_init);
1277
1278 static void __exit vhci_cleanup(void)
1279 {
1280         usbip_dbg_vhci_hc("enter\n");
1281
1282         platform_device_unregister(&the_pdev);
1283         platform_driver_unregister(&vhci_driver);
1284
1285         usbip_dbg_vhci_hc("bye\n");
1286 }
1287 module_exit(vhci_cleanup);