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Linux/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 #include <linux/init.h>
 21 #include <linux/file.h>
 22 #include <linux/kernel.h>
 23 #include <linux/kthread.h>
 24 #include <linux/module.h>
 25 #include <linux/platform_device.h>
 26 #include <linux/slab.h>
 27 
 28 #include "usbip_common.h"
 29 #include "vhci.h"
 30 
 31 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
 32 #define DRIVER_DESC "USB/IP 'Virtual' Host Controller (VHCI) Driver"
 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 /* See usb gadget dummy hcd */
 45 
 46 static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
 47 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 48                             u16 wIndex, char *buff, u16 wLength);
 49 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 50                             gfp_t mem_flags);
 51 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
 52 static int vhci_start(struct usb_hcd *vhci_hcd);
 53 static void vhci_stop(struct usb_hcd *hcd);
 54 static int vhci_get_frame_number(struct usb_hcd *hcd);
 55 
 56 static const char driver_name[] = "vhci_hcd";
 57 static const char driver_desc[] = "USB/IP Virtual Host Controller";
 58 
 59 struct vhci_hcd *the_controller;
 60 
 61 static const char * const bit_desc[] = {
 62         "CONNECTION",           /**/
 63         "ENABLE",               /*1*/
 64         "SUSPEND",              /*2*/
 65         "OVER_CURRENT",         /*3*/
 66         "RESET",                /*4*/
 67         "R5",                   /*5*/
 68         "R6",                   /*6*/
 69         "R7",                   /*7*/
 70         "POWER",                /*8*/
 71         "LOWSPEED",             /*9*/
 72         "HIGHSPEED",            /*10*/
 73         "PORT_TEST",            /*11*/
 74         "INDICATOR",            /*12*/
 75         "R13",                  /*13*/
 76         "R14",                  /*14*/
 77         "R15",                  /*15*/
 78         "C_CONNECTION",         /*16*/
 79         "C_ENABLE",             /*17*/
 80         "C_SUSPEND",            /*18*/
 81         "C_OVER_CURRENT",       /*19*/
 82         "C_RESET",              /*20*/
 83         "R21",                  /*21*/
 84         "R22",                  /*22*/
 85         "R23",                  /*23*/
 86         "R24",                  /*24*/
 87         "R25",                  /*25*/
 88         "R26",                  /*26*/
 89         "R27",                  /*27*/
 90         "R28",                  /*28*/
 91         "R29",                  /*29*/
 92         "R30",                  /*30*/
 93         "R31",                  /*31*/
 94 };
 95 
 96 static void dump_port_status_diff(u32 prev_status, u32 new_status)
 97 {
 98         int i = 0;
 99         u32 bit = 1;
100 
101         pr_debug("status prev -> new: %08x -> %08x\n", prev_status, new_status);
102         while (bit) {
103                 u32 prev = prev_status & bit;
104                 u32 new = new_status & bit;
105                 char change;
106 
107                 if (!prev && new)
108                         change = '+';
109                 else if (prev && !new)
110                         change = '-';
111                 else
112                         change = ' ';
113 
114                 if (prev || new)
115                         pr_debug(" %c%s\n", change, bit_desc[i]);
116                 bit <<= 1;
117                 i++;
118         }
119         pr_debug("\n");
120 }
121 
122 void rh_port_connect(int rhport, enum usb_device_speed speed)
123 {
124         usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
125 
126         spin_lock(&the_controller->lock);
127 
128         the_controller->port_status[rhport] |= USB_PORT_STAT_CONNECTION
129                 | (1 << USB_PORT_FEAT_C_CONNECTION);
130 
131         switch (speed) {
132         case USB_SPEED_HIGH:
133                 the_controller->port_status[rhport] |= USB_PORT_STAT_HIGH_SPEED;
134                 break;
135         case USB_SPEED_LOW:
136                 the_controller->port_status[rhport] |= USB_PORT_STAT_LOW_SPEED;
137                 break;
138         default:
139                 break;
140         }
141 
142         spin_unlock(&the_controller->lock);
143 
144         usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
145 }
146 
147 static void rh_port_disconnect(int rhport)
148 {
149         usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
150 
151         spin_lock(&the_controller->lock);
152 
153         the_controller->port_status[rhport] &= ~USB_PORT_STAT_CONNECTION;
154         the_controller->port_status[rhport] |=
155                                         (1 << USB_PORT_FEAT_C_CONNECTION);
156 
157         spin_unlock(&the_controller->lock);
158         usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
159 }
160 
161 #define PORT_C_MASK                             \
162         ((USB_PORT_STAT_C_CONNECTION            \
163           | USB_PORT_STAT_C_ENABLE              \
164           | USB_PORT_STAT_C_SUSPEND             \
165           | USB_PORT_STAT_C_OVERCURRENT         \
166           | USB_PORT_STAT_C_RESET) << 16)
167 
168 /*
169  * Returns 0 if the status hasn't changed, or the number of bytes in buf.
170  * Ports are 0-indexed from the HCD point of view,
171  * and 1-indexed from the USB core pointer of view.
172  *
173  * @buf: a bitmap to show which port status has been changed.
174  *  bit  0: reserved
175  *  bit  1: the status of port 0 has been changed.
176  *  bit  2: the status of port 1 has been changed.
177  *  ...
178  */
179 static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
180 {
181         struct vhci_hcd *vhci;
182         int             retval;
183         int             rhport;
184         int             changed = 0;
185 
186         retval = DIV_ROUND_UP(VHCI_NPORTS + 1, 8);
187         memset(buf, 0, retval);
188 
189         vhci = hcd_to_vhci(hcd);
190 
191         spin_lock(&vhci->lock);
192         if (!HCD_HW_ACCESSIBLE(hcd)) {
193                 usbip_dbg_vhci_rh("hw accessible flag not on?\n");
194                 goto done;
195         }
196 
197         /* check pseudo status register for each port */
198         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
199                 if ((vhci->port_status[rhport] & PORT_C_MASK)) {
200                         /* The status of a port has been changed, */
201                         usbip_dbg_vhci_rh("port %d status changed\n", rhport);
202 
203                         buf[(rhport + 1) / 8] |= 1 << (rhport + 1) % 8;
204                         changed = 1;
205                 }
206         }
207 
208         pr_info("changed %d\n", changed);
209 
210         if ((hcd->state == HC_STATE_SUSPENDED) && (changed == 1))
211                 usb_hcd_resume_root_hub(hcd);
212 
213 done:
214         spin_unlock(&vhci->lock);
215         return changed ? retval : 0;
216 }
217 
218 static inline void hub_descriptor(struct usb_hub_descriptor *desc)
219 {
220         memset(desc, 0, sizeof(*desc));
221         desc->bDescriptorType = 0x29;
222         desc->bDescLength = 9;
223         desc->wHubCharacteristics = (__constant_cpu_to_le16(0x0001));
224         desc->bNbrPorts = VHCI_NPORTS;
225         desc->u.hs.DeviceRemovable[0] = 0xff;
226         desc->u.hs.DeviceRemovable[1] = 0xff;
227 }
228 
229 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
230                             u16 wIndex, char *buf, u16 wLength)
231 {
232         struct vhci_hcd *dum;
233         int             retval = 0;
234         int             rhport;
235 
236         u32 prev_port_status[VHCI_NPORTS];
237 
238         if (!HCD_HW_ACCESSIBLE(hcd))
239                 return -ETIMEDOUT;
240 
241         /*
242          * NOTE:
243          * wIndex shows the port number and begins from 1.
244          */
245         usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
246                           wIndex);
247         if (wIndex > VHCI_NPORTS)
248                 pr_err("invalid port number %d\n", wIndex);
249         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
250 
251         dum = hcd_to_vhci(hcd);
252 
253         spin_lock(&dum->lock);
254 
255         /* store old status and compare now and old later */
256         if (usbip_dbg_flag_vhci_rh) {
257                 memcpy(prev_port_status, dum->port_status,
258                         sizeof(prev_port_status));
259         }
260 
261         switch (typeReq) {
262         case ClearHubFeature:
263                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
264                 break;
265         case ClearPortFeature:
266                 switch (wValue) {
267                 case USB_PORT_FEAT_SUSPEND:
268                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
269                                 /* 20msec signaling */
270                                 dum->resuming = 1;
271                                 dum->re_timeout =
272                                         jiffies + msecs_to_jiffies(20);
273                         }
274                         break;
275                 case USB_PORT_FEAT_POWER:
276                         usbip_dbg_vhci_rh(" ClearPortFeature: "
277                                           "USB_PORT_FEAT_POWER\n");
278                         dum->port_status[rhport] = 0;
279                         dum->resuming = 0;
280                         break;
281                 case USB_PORT_FEAT_C_RESET:
282                         usbip_dbg_vhci_rh(" ClearPortFeature: "
283                                           "USB_PORT_FEAT_C_RESET\n");
284                         switch (dum->vdev[rhport].speed) {
285                         case USB_SPEED_HIGH:
286                                 dum->port_status[rhport] |=
287                                         USB_PORT_STAT_HIGH_SPEED;
288                                 break;
289                         case USB_SPEED_LOW:
290                                 dum->port_status[rhport] |=
291                                         USB_PORT_STAT_LOW_SPEED;
292                                 break;
293                         default:
294                                 break;
295                         }
296                 default:
297                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
298                                           wValue);
299                         dum->port_status[rhport] &= ~(1 << wValue);
300                         break;
301                 }
302                 break;
303         case GetHubDescriptor:
304                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
305                 hub_descriptor((struct usb_hub_descriptor *) buf);
306                 break;
307         case GetHubStatus:
308                 usbip_dbg_vhci_rh(" GetHubStatus\n");
309                 *(__le32 *) buf = __constant_cpu_to_le32(0);
310                 break;
311         case GetPortStatus:
312                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
313                 if (wIndex > VHCI_NPORTS || wIndex < 1) {
314                         pr_err("invalid port number %d\n", wIndex);
315                         retval = -EPIPE;
316                 }
317 
318                 /* we do not care about resume. */
319 
320                 /* whoever resets or resumes must GetPortStatus to
321                  * complete it!!
322                  */
323                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
324                         dum->port_status[rhport] |=
325                                 (1 << USB_PORT_FEAT_C_SUSPEND);
326                         dum->port_status[rhport] &=
327                                 ~(1 << USB_PORT_FEAT_SUSPEND);
328                         dum->resuming = 0;
329                         dum->re_timeout = 0;
330                 }
331 
332                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
333                     0 && time_after(jiffies, dum->re_timeout)) {
334                         dum->port_status[rhport] |=
335                                 (1 << USB_PORT_FEAT_C_RESET);
336                         dum->port_status[rhport] &=
337                                 ~(1 << USB_PORT_FEAT_RESET);
338                         dum->re_timeout = 0;
339 
340                         if (dum->vdev[rhport].ud.status ==
341                             VDEV_ST_NOTASSIGNED) {
342                                 usbip_dbg_vhci_rh(" enable rhport %d "
343                                                   "(status %u)\n",
344                                                   rhport,
345                                                   dum->vdev[rhport].ud.status);
346                                 dum->port_status[rhport] |=
347                                         USB_PORT_STAT_ENABLE;
348                         }
349                 }
350                 ((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
351                 ((__le16 *) buf)[1] = cpu_to_le16(dum->port_status[rhport] >> 16);
352 
353                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
354                                   ((u16 *)buf)[1]);
355                 break;
356         case SetHubFeature:
357                 usbip_dbg_vhci_rh(" SetHubFeature\n");
358                 retval = -EPIPE;
359                 break;
360         case SetPortFeature:
361                 switch (wValue) {
362                 case USB_PORT_FEAT_SUSPEND:
363                         usbip_dbg_vhci_rh(" SetPortFeature: "
364                                           "USB_PORT_FEAT_SUSPEND\n");
365                         break;
366                 case USB_PORT_FEAT_RESET:
367                         usbip_dbg_vhci_rh(" SetPortFeature: "
368                                           "USB_PORT_FEAT_RESET\n");
369                         /* if it's already running, disconnect first */
370                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
371                                 dum->port_status[rhport] &=
372                                         ~(USB_PORT_STAT_ENABLE |
373                                           USB_PORT_STAT_LOW_SPEED |
374                                           USB_PORT_STAT_HIGH_SPEED);
375                                 /* FIXME test that code path! */
376                         }
377                         /* 50msec reset signaling */
378                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
379 
380                         /* FALLTHROUGH */
381                 default:
382                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
383                                           wValue);
384                         dum->port_status[rhport] |= (1 << wValue);
385                         break;
386                 }
387                 break;
388 
389         default:
390                 pr_err("default: no such request\n");
391 
392                 /* "protocol stall" on error */
393                 retval = -EPIPE;
394         }
395 
396         if (usbip_dbg_flag_vhci_rh) {
397                 pr_debug("port %d\n", rhport);
398                 /* Only dump valid port status */
399                 if (rhport >= 0) {
400                         dump_port_status_diff(prev_port_status[rhport],
401                                               dum->port_status[rhport]);
402                 }
403         }
404         usbip_dbg_vhci_rh(" bye\n");
405 
406         spin_unlock(&dum->lock);
407 
408         return retval;
409 }
410 
411 static struct vhci_device *get_vdev(struct usb_device *udev)
412 {
413         int i;
414 
415         if (!udev)
416                 return NULL;
417 
418         for (i = 0; i < VHCI_NPORTS; i++)
419                 if (the_controller->vdev[i].udev == udev)
420                         return port_to_vdev(i);
421 
422         return NULL;
423 }
424 
425 static void vhci_tx_urb(struct urb *urb)
426 {
427         struct vhci_device *vdev = get_vdev(urb->dev);
428         struct vhci_priv *priv;
429 
430         if (!vdev) {
431                 pr_err("could not get virtual device");
432                 return;
433         }
434 
435         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
436         if (!priv) {
437                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
438                 return;
439         }
440 
441         spin_lock(&vdev->priv_lock);
442 
443         priv->seqnum = atomic_inc_return(&the_controller->seqnum);
444         if (priv->seqnum == 0xffff)
445                 dev_info(&urb->dev->dev, "seqnum max\n");
446 
447         priv->vdev = vdev;
448         priv->urb = urb;
449 
450         urb->hcpriv = (void *) priv;
451 
452         list_add_tail(&priv->list, &vdev->priv_tx);
453 
454         wake_up(&vdev->waitq_tx);
455         spin_unlock(&vdev->priv_lock);
456 }
457 
458 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
459                             gfp_t mem_flags)
460 {
461         struct device *dev = &urb->dev->dev;
462         int ret = 0;
463         struct vhci_device *vdev;
464 
465         usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
466                           hcd, urb, mem_flags);
467 
468         /* patch to usb_sg_init() is in 2.5.60 */
469         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
470 
471         spin_lock(&the_controller->lock);
472 
473         if (urb->status != -EINPROGRESS) {
474                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
475                 spin_unlock(&the_controller->lock);
476                 return urb->status;
477         }
478 
479         vdev = port_to_vdev(urb->dev->portnum-1);
480 
481         /* refuse enqueue for dead connection */
482         spin_lock(&vdev->ud.lock);
483         if (vdev->ud.status == VDEV_ST_NULL ||
484             vdev->ud.status == VDEV_ST_ERROR) {
485                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
486                 spin_unlock(&vdev->ud.lock);
487                 spin_unlock(&the_controller->lock);
488                 return -ENODEV;
489         }
490         spin_unlock(&vdev->ud.lock);
491 
492         ret = usb_hcd_link_urb_to_ep(hcd, urb);
493         if (ret)
494                 goto no_need_unlink;
495 
496         /*
497          * The enumeration process is as follows;
498          *
499          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
500          *     to get max packet length of default pipe
501          *
502          *  2. Set_Address request to DevAddr(0) EndPoint(0)
503          *
504          */
505         if (usb_pipedevice(urb->pipe) == 0) {
506                 __u8 type = usb_pipetype(urb->pipe);
507                 struct usb_ctrlrequest *ctrlreq =
508                         (struct usb_ctrlrequest *) urb->setup_packet;
509 
510                 if (type != PIPE_CONTROL || !ctrlreq) {
511                         dev_err(dev, "invalid request to devnum 0\n");
512                         ret = -EINVAL;
513                         goto no_need_xmit;
514                 }
515 
516                 switch (ctrlreq->bRequest) {
517                 case USB_REQ_SET_ADDRESS:
518                         /* set_address may come when a device is reset */
519                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
520                                  ctrlreq->wValue, vdev->rhport);
521 
522                         if (vdev->udev)
523                                 usb_put_dev(vdev->udev);
524                         vdev->udev = usb_get_dev(urb->dev);
525 
526                         spin_lock(&vdev->ud.lock);
527                         vdev->ud.status = VDEV_ST_USED;
528                         spin_unlock(&vdev->ud.lock);
529 
530                         if (urb->status == -EINPROGRESS) {
531                                 /* This request is successfully completed. */
532                                 /* If not -EINPROGRESS, possibly unlinked. */
533                                 urb->status = 0;
534                         }
535 
536                         goto no_need_xmit;
537 
538                 case USB_REQ_GET_DESCRIPTOR:
539                         if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
540                                 usbip_dbg_vhci_hc("Not yet?: "
541                                                   "Get_Descriptor to device 0 "
542                                                   "(get max pipe size)\n");
543 
544                         if (vdev->udev)
545                                 usb_put_dev(vdev->udev);
546                         vdev->udev = usb_get_dev(urb->dev);
547                         goto out;
548 
549                 default:
550                         /* NOT REACHED */
551                         dev_err(dev, "invalid request to devnum 0 bRequest %u, "
552                                 "wValue %u\n", ctrlreq->bRequest,
553                                 ctrlreq->wValue);
554                         ret =  -EINVAL;
555                         goto no_need_xmit;
556                 }
557 
558         }
559 
560 out:
561         vhci_tx_urb(urb);
562         spin_unlock(&the_controller->lock);
563 
564         return 0;
565 
566 no_need_xmit:
567         usb_hcd_unlink_urb_from_ep(hcd, urb);
568 no_need_unlink:
569         spin_unlock(&the_controller->lock);
570         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
571         return ret;
572 }
573 
574 /*
575  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
576  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
577  * back its urb. For the driver unlinking the urb, the content of the urb is
578  * not important, but the calling to its completion handler is important; the
579  * completion of unlinking is notified by the completion handler.
580  *
581  *
582  * CLIENT SIDE
583  *
584  * - When vhci_hcd receives RET_SUBMIT,
585  *
586  *      - case 1a). the urb of the pdu is not unlinking.
587  *              - normal case
588  *              => just give back the urb
589  *
590  *      - case 1b). the urb of the pdu is unlinking.
591  *              - usbip.ko will return a reply of the unlinking request.
592  *              => give back the urb now and go to case 2b).
593  *
594  * - When vhci_hcd receives RET_UNLINK,
595  *
596  *      - case 2a). a submit request is still pending in vhci_hcd.
597  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
598  *                completed there.
599  *              => free a pending submit request
600  *              => notify unlink completeness by giving back the urb
601  *
602  *      - case 2b). a submit request is *not* pending in vhci_hcd.
603  *              - urb was already given back to the core driver.
604  *              => do not give back the urb
605  *
606  *
607  * SERVER SIDE
608  *
609  * - When usbip receives CMD_UNLINK,
610  *
611  *      - case 3a). the urb of the unlink request is now in submission.
612  *              => do usb_unlink_urb().
613  *              => after the unlink is completed, send RET_UNLINK.
614  *
615  *      - case 3b). the urb of the unlink request is not in submission.
616  *              - may be already completed or never be received
617  *              => send RET_UNLINK
618  *
619  */
620 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
621 {
622         struct vhci_priv *priv;
623         struct vhci_device *vdev;
624 
625         pr_info("dequeue a urb %p\n", urb);
626 
627         spin_lock(&the_controller->lock);
628 
629         priv = urb->hcpriv;
630         if (!priv) {
631                 /* URB was never linked! or will be soon given back by
632                  * vhci_rx. */
633                 spin_unlock(&the_controller->lock);
634                 return 0;
635         }
636 
637         {
638                 int ret = 0;
639                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
640                 if (ret) {
641                         spin_unlock(&the_controller->lock);
642                         return ret;
643                 }
644         }
645 
646          /* send unlink request here? */
647         vdev = priv->vdev;
648 
649         if (!vdev->ud.tcp_socket) {
650                 /* tcp connection is closed */
651                 spin_lock(&vdev->priv_lock);
652 
653                 pr_info("device %p seems to be disconnected\n", vdev);
654                 list_del(&priv->list);
655                 kfree(priv);
656                 urb->hcpriv = NULL;
657 
658                 spin_unlock(&vdev->priv_lock);
659 
660                 /*
661                  * If tcp connection is alive, we have sent CMD_UNLINK.
662                  * vhci_rx will receive RET_UNLINK and give back the URB.
663                  * Otherwise, we give back it here.
664                  */
665                 pr_info("gives back urb %p\n", urb);
666 
667                 usb_hcd_unlink_urb_from_ep(hcd, urb);
668 
669                 spin_unlock(&the_controller->lock);
670                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
671                                      urb->status);
672                 spin_lock(&the_controller->lock);
673 
674         } else {
675                 /* tcp connection is alive */
676                 struct vhci_unlink *unlink;
677 
678                 spin_lock(&vdev->priv_lock);
679 
680                 /* setup CMD_UNLINK pdu */
681                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
682                 if (!unlink) {
683                         spin_unlock(&vdev->priv_lock);
684                         spin_unlock(&the_controller->lock);
685                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
686                         return -ENOMEM;
687                 }
688 
689                 unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
690                 if (unlink->seqnum == 0xffff)
691                         pr_info("seqnum max\n");
692 
693                 unlink->unlink_seqnum = priv->seqnum;
694 
695                 pr_info("device %p seems to be still connected\n", vdev);
696 
697                 /* send cmd_unlink and try to cancel the pending URB in the
698                  * peer */
699                 list_add_tail(&unlink->list, &vdev->unlink_tx);
700                 wake_up(&vdev->waitq_tx);
701 
702                 spin_unlock(&vdev->priv_lock);
703         }
704 
705         spin_unlock(&the_controller->lock);
706 
707         usbip_dbg_vhci_hc("leave\n");
708         return 0;
709 }
710 
711 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
712 {
713         struct vhci_unlink *unlink, *tmp;
714 
715         spin_lock(&the_controller->lock);
716         spin_lock(&vdev->priv_lock);
717 
718         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
719                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
720                 list_del(&unlink->list);
721                 kfree(unlink);
722         }
723 
724         while (!list_empty(&vdev->unlink_rx)) {
725                 struct urb *urb;
726 
727                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
728                         list);
729 
730                 /* give back URB of unanswered unlink request */
731                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
732 
733                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
734                 if (!urb) {
735                         pr_info("the urb (seqnum %lu) was already given back\n",
736                                 unlink->unlink_seqnum);
737                         list_del(&unlink->list);
738                         kfree(unlink);
739                         continue;
740                 }
741 
742                 urb->status = -ENODEV;
743 
744                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
745 
746                 list_del(&unlink->list);
747 
748                 spin_unlock(&vdev->priv_lock);
749                 spin_unlock(&the_controller->lock);
750 
751                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
752                                      urb->status);
753 
754                 spin_lock(&the_controller->lock);
755                 spin_lock(&vdev->priv_lock);
756 
757                 kfree(unlink);
758         }
759 
760         spin_unlock(&vdev->priv_lock);
761         spin_unlock(&the_controller->lock);
762 }
763 
764 /*
765  * The important thing is that only one context begins cleanup.
766  * This is why error handling and cleanup become simple.
767  * We do not want to consider race condition as possible.
768  */
769 static void vhci_shutdown_connection(struct usbip_device *ud)
770 {
771         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
772 
773         /* need this? see stub_dev.c */
774         if (ud->tcp_socket) {
775                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
776                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
777         }
778 
779         /* kill threads related to this sdev */
780         if (vdev->ud.tcp_rx) {
781                 kthread_stop_put(vdev->ud.tcp_rx);
782                 vdev->ud.tcp_rx = NULL;
783         }
784         if (vdev->ud.tcp_tx) {
785                 kthread_stop_put(vdev->ud.tcp_tx);
786                 vdev->ud.tcp_tx = NULL;
787         }
788         pr_info("stop threads\n");
789 
790         /* active connection is closed */
791         if (vdev->ud.tcp_socket) {
792                 fput(vdev->ud.tcp_socket->file);
793                 vdev->ud.tcp_socket = NULL;
794         }
795         pr_info("release socket\n");
796 
797         vhci_device_unlink_cleanup(vdev);
798 
799         /*
800          * rh_port_disconnect() is a trigger of ...
801          *   usb_disable_device():
802          *      disable all the endpoints for a USB device.
803          *   usb_disable_endpoint():
804          *      disable endpoints. pending urbs are unlinked(dequeued).
805          *
806          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
807          * detached device should release used urbs in a cleanup function (i.e.
808          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
809          * pushed urbs and their private data in this function.
810          *
811          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
812          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
813          * gives back pushed urbs and frees their private data by request of
814          * the cleanup function of a USB driver. When unlinking a urb with an
815          * active connection, vhci_dequeue() does not give back the urb which
816          * is actually given back by vhci_rx after receiving its return pdu.
817          *
818          */
819         rh_port_disconnect(vdev->rhport);
820 
821         pr_info("disconnect device\n");
822 }
823 
824 
825 static void vhci_device_reset(struct usbip_device *ud)
826 {
827         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
828 
829         spin_lock(&ud->lock);
830 
831         vdev->speed  = 0;
832         vdev->devid  = 0;
833 
834         if (vdev->udev)
835                 usb_put_dev(vdev->udev);
836         vdev->udev = NULL;
837 
838         if (ud->tcp_socket) {
839                 fput(ud->tcp_socket->file);
840                 ud->tcp_socket = NULL;
841         }
842         ud->status = VDEV_ST_NULL;
843 
844         spin_unlock(&ud->lock);
845 }
846 
847 static void vhci_device_unusable(struct usbip_device *ud)
848 {
849         spin_lock(&ud->lock);
850         ud->status = VDEV_ST_ERROR;
851         spin_unlock(&ud->lock);
852 }
853 
854 static void vhci_device_init(struct vhci_device *vdev)
855 {
856         memset(vdev, 0, sizeof(*vdev));
857 
858         vdev->ud.side   = USBIP_VHCI;
859         vdev->ud.status = VDEV_ST_NULL;
860         spin_lock_init(&vdev->ud.lock);
861 
862         INIT_LIST_HEAD(&vdev->priv_rx);
863         INIT_LIST_HEAD(&vdev->priv_tx);
864         INIT_LIST_HEAD(&vdev->unlink_tx);
865         INIT_LIST_HEAD(&vdev->unlink_rx);
866         spin_lock_init(&vdev->priv_lock);
867 
868         init_waitqueue_head(&vdev->waitq_tx);
869 
870         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
871         vdev->ud.eh_ops.reset = vhci_device_reset;
872         vdev->ud.eh_ops.unusable = vhci_device_unusable;
873 
874         usbip_start_eh(&vdev->ud);
875 }
876 
877 static int vhci_start(struct usb_hcd *hcd)
878 {
879         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
880         int rhport;
881         int err = 0;
882 
883         usbip_dbg_vhci_hc("enter vhci_start\n");
884 
885         /* initialize private data of usb_hcd */
886 
887         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
888                 struct vhci_device *vdev = &vhci->vdev[rhport];
889                 vhci_device_init(vdev);
890                 vdev->rhport = rhport;
891         }
892 
893         atomic_set(&vhci->seqnum, 0);
894         spin_lock_init(&vhci->lock);
895 
896         hcd->power_budget = 0; /* no limit */
897         hcd->uses_new_polling = 1;
898 
899         /* vhci_hcd is now ready to be controlled through sysfs */
900         err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
901         if (err) {
902                 pr_err("create sysfs files\n");
903                 return err;
904         }
905 
906         return 0;
907 }
908 
909 static void vhci_stop(struct usb_hcd *hcd)
910 {
911         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
912         int rhport = 0;
913 
914         usbip_dbg_vhci_hc("stop VHCI controller\n");
915 
916         /* 1. remove the userland interface of vhci_hcd */
917         sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
918 
919         /* 2. shutdown all the ports of vhci_hcd */
920         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
921                 struct vhci_device *vdev = &vhci->vdev[rhport];
922 
923                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
924                 usbip_stop_eh(&vdev->ud);
925         }
926 }
927 
928 static int vhci_get_frame_number(struct usb_hcd *hcd)
929 {
930         pr_err("Not yet implemented\n");
931         return 0;
932 }
933 
934 #ifdef CONFIG_PM
935 
936 /* FIXME: suspend/resume */
937 static int vhci_bus_suspend(struct usb_hcd *hcd)
938 {
939         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
940 
941         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
942 
943         spin_lock(&vhci->lock);
944         hcd->state = HC_STATE_SUSPENDED;
945         spin_unlock(&vhci->lock);
946 
947         return 0;
948 }
949 
950 static int vhci_bus_resume(struct usb_hcd *hcd)
951 {
952         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
953         int rc = 0;
954 
955         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
956 
957         spin_lock(&vhci->lock);
958         if (!HCD_HW_ACCESSIBLE(hcd))
959                 rc = -ESHUTDOWN;
960         else
961                 hcd->state = HC_STATE_RUNNING;
962         spin_unlock(&vhci->lock);
963 
964         return rc;
965 }
966 
967 #else
968 
969 #define vhci_bus_suspend      NULL
970 #define vhci_bus_resume       NULL
971 #endif
972 
973 static struct hc_driver vhci_hc_driver = {
974         .description    = driver_name,
975         .product_desc   = driver_desc,
976         .hcd_priv_size  = sizeof(struct vhci_hcd),
977 
978         .flags          = HCD_USB2,
979 
980         .start          = vhci_start,
981         .stop           = vhci_stop,
982 
983         .urb_enqueue    = vhci_urb_enqueue,
984         .urb_dequeue    = vhci_urb_dequeue,
985 
986         .get_frame_number = vhci_get_frame_number,
987 
988         .hub_status_data = vhci_hub_status,
989         .hub_control    = vhci_hub_control,
990         .bus_suspend    = vhci_bus_suspend,
991         .bus_resume     = vhci_bus_resume,
992 };
993 
994 static int vhci_hcd_probe(struct platform_device *pdev)
995 {
996         struct usb_hcd          *hcd;
997         int                     ret;
998 
999         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1000 
1001         /*
1002          * Allocate and initialize hcd.
1003          * Our private data is also allocated automatically.
1004          */
1005         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1006         if (!hcd) {
1007                 pr_err("create hcd failed\n");
1008                 return -ENOMEM;
1009         }
1010         hcd->has_tt = 1;
1011 
1012         /* this is private data for vhci_hcd */
1013         the_controller = hcd_to_vhci(hcd);
1014 
1015         /*
1016          * Finish generic HCD structure initialization and register.
1017          * Call the driver's reset() and start() routines.
1018          */
1019         ret = usb_add_hcd(hcd, 0, 0);
1020         if (ret != 0) {
1021                 pr_err("usb_add_hcd failed %d\n", ret);
1022                 usb_put_hcd(hcd);
1023                 the_controller = NULL;
1024                 return ret;
1025         }
1026 
1027         usbip_dbg_vhci_hc("bye\n");
1028         return 0;
1029 }
1030 
1031 static int vhci_hcd_remove(struct platform_device *pdev)
1032 {
1033         struct usb_hcd  *hcd;
1034 
1035         hcd = platform_get_drvdata(pdev);
1036         if (!hcd)
1037                 return 0;
1038 
1039         /*
1040          * Disconnects the root hub,
1041          * then reverses the effects of usb_add_hcd(),
1042          * invoking the HCD's stop() methods.
1043          */
1044         usb_remove_hcd(hcd);
1045         usb_put_hcd(hcd);
1046         the_controller = NULL;
1047 
1048         return 0;
1049 }
1050 
1051 #ifdef CONFIG_PM
1052 
1053 /* what should happen for USB/IP under suspend/resume? */
1054 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1055 {
1056         struct usb_hcd *hcd;
1057         int rhport = 0;
1058         int connected = 0;
1059         int ret = 0;
1060 
1061         hcd = platform_get_drvdata(pdev);
1062 
1063         spin_lock(&the_controller->lock);
1064 
1065         for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1066                 if (the_controller->port_status[rhport] &
1067                     USB_PORT_STAT_CONNECTION)
1068                         connected += 1;
1069 
1070         spin_unlock(&the_controller->lock);
1071 
1072         if (connected > 0) {
1073                 dev_info(&pdev->dev, "We have %d active connection%s. Do not "
1074                          "suspend.\n", connected, (connected == 1 ? "" : "s"));
1075                 ret =  -EBUSY;
1076         } else {
1077                 dev_info(&pdev->dev, "suspend vhci_hcd");
1078                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1079         }
1080 
1081         return ret;
1082 }
1083 
1084 static int vhci_hcd_resume(struct platform_device *pdev)
1085 {
1086         struct usb_hcd *hcd;
1087 
1088         dev_dbg(&pdev->dev, "%s\n", __func__);
1089 
1090         hcd = platform_get_drvdata(pdev);
1091         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1092         usb_hcd_poll_rh_status(hcd);
1093 
1094         return 0;
1095 }
1096 
1097 #else
1098 
1099 #define vhci_hcd_suspend        NULL
1100 #define vhci_hcd_resume         NULL
1101 
1102 #endif
1103 
1104 static struct platform_driver vhci_driver = {
1105         .probe  = vhci_hcd_probe,
1106         .remove = vhci_hcd_remove,
1107         .suspend = vhci_hcd_suspend,
1108         .resume = vhci_hcd_resume,
1109         .driver = {
1110                 .name = driver_name,
1111                 .owner = THIS_MODULE,
1112         },
1113 };
1114 
1115 /*
1116  * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1117  * We need to add this virtual device as a platform device arbitrarily:
1118  *      1. platform_device_register()
1119  */
1120 static void the_pdev_release(struct device *dev)
1121 {
1122         return;
1123 }
1124 
1125 static struct platform_device the_pdev = {
1126         /* should be the same name as driver_name */
1127         .name = driver_name,
1128         .id = -1,
1129         .dev = {
1130                 .release = the_pdev_release,
1131         },
1132 };
1133 
1134 static int __init vhci_hcd_init(void)
1135 {
1136         int ret;
1137 
1138         if (usb_disabled())
1139                 return -ENODEV;
1140 
1141         ret = platform_driver_register(&vhci_driver);
1142         if (ret)
1143                 goto err_driver_register;
1144 
1145         ret = platform_device_register(&the_pdev);
1146         if (ret)
1147                 goto err_platform_device_register;
1148 
1149         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1150         return ret;
1151 
1152 err_platform_device_register:
1153         platform_driver_unregister(&vhci_driver);
1154 err_driver_register:
1155         return ret;
1156 }
1157 
1158 static void __exit vhci_hcd_exit(void)
1159 {
1160         platform_device_unregister(&the_pdev);
1161         platform_driver_unregister(&vhci_driver);
1162 }
1163 
1164 module_init(vhci_hcd_init);
1165 module_exit(vhci_hcd_exit);
1166 
1167 MODULE_AUTHOR(DRIVER_AUTHOR);
1168 MODULE_DESCRIPTION(DRIVER_DESC);
1169 MODULE_LICENSE("GPL");
1170 MODULE_VERSION(USBIP_VERSION);
1171 

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