drivers/usb/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",           /*0*/
  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         if ((hcd->state == HC_STATE_SUSPENDED) && (changed == 1))
 209                 usb_hcd_resume_root_hub(hcd);
 210
 211 done:
 212         spin_unlock(&vhci->lock);
 213         return changed ? retval : 0;
 214 }
 215
 216 static inline void hub_descriptor(struct usb_hub_descriptor *desc)
 217 {
 218         memset(desc, 0, sizeof(*desc));
 219         desc->bDescriptorType = 0x29;
 220         desc->bDescLength = 9;
 221         desc->wHubCharacteristics = (__constant_cpu_to_le16(0x0001));
 222         desc->bNbrPorts = VHCI_NPORTS;
 223         desc->u.hs.DeviceRemovable[0] = 0xff;
 224         desc->u.hs.DeviceRemovable[1] = 0xff;
 225 }
 226
 227 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 228                             u16 wIndex, char *buf, u16 wLength)
 229 {
 230         struct vhci_hcd *dum;
 231         int             retval = 0;
 232         int             rhport;
 233
 234         u32 prev_port_status[VHCI_NPORTS];
 235
 236         if (!HCD_HW_ACCESSIBLE(hcd))
 237                 return -ETIMEDOUT;
 238
 239         /*
 240          * NOTE:
 241          * wIndex shows the port number and begins from 1.
 242          */
 243         usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 244                           wIndex);
 245         if (wIndex > VHCI_NPORTS)
 246                 pr_err("invalid port number %d\n", wIndex);
 247         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 248
 249         dum = hcd_to_vhci(hcd);
 250
 251         spin_lock(&dum->lock);
 252
 253         /* store old status and compare now and old later */
 254         if (usbip_dbg_flag_vhci_rh) {
 255                 memcpy(prev_port_status, dum->port_status,
 256                         sizeof(prev_port_status));
 257         }
 258
 259         switch (typeReq) {
 260         case ClearHubFeature:
 261                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
 262                 break;
 263         case ClearPortFeature:
 264                 switch (wValue) {
 265                 case USB_PORT_FEAT_SUSPEND:
 266                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
 267                                 /* 20msec signaling */
 268                                 dum->resuming = 1;
 269                                 dum->re_timeout =
 270                                         jiffies + msecs_to_jiffies(20);
 271                         }
 272                         break;
 273                 case USB_PORT_FEAT_POWER:
 274                         usbip_dbg_vhci_rh(
 275                                 " ClearPortFeature: USB_PORT_FEAT_POWER\n");
 276                         dum->port_status[rhport] = 0;
 277                         dum->resuming = 0;
 278                         break;
 279                 case USB_PORT_FEAT_C_RESET:
 280                         usbip_dbg_vhci_rh(
 281                                 " ClearPortFeature: USB_PORT_FEAT_C_RESET\n");
 282                         switch (dum->vdev[rhport].speed) {
 283                         case USB_SPEED_HIGH:
 284                                 dum->port_status[rhport] |=
 285                                         USB_PORT_STAT_HIGH_SPEED;
 286                                 break;
 287                         case USB_SPEED_LOW:
 288                                 dum->port_status[rhport] |=
 289                                         USB_PORT_STAT_LOW_SPEED;
 290                                 break;
 291                         default:
 292                                 break;
 293                         }
 294                 default:
 295                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 296                                           wValue);
 297                         dum->port_status[rhport] &= ~(1 << wValue);
 298                         break;
 299                 }
 300                 break;
 301         case GetHubDescriptor:
 302                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 303                 hub_descriptor((struct usb_hub_descriptor *) buf);
 304                 break;
 305         case GetHubStatus:
 306                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 307                 *(__le32 *) buf = cpu_to_le32(0);
 308                 break;
 309         case GetPortStatus:
 310                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 311                 if (wIndex > VHCI_NPORTS || wIndex < 1) {
 312                         pr_err("invalid port number %d\n", wIndex);
 313                         retval = -EPIPE;
 314                 }
 315
 316                 /* we do not care about resume. */
 317
 318                 /* whoever resets or resumes must GetPortStatus to
 319                  * complete it!!
 320                  */
 321                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 322                         dum->port_status[rhport] |=
 323                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 324                         dum->port_status[rhport] &=
 325                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 326                         dum->resuming = 0;
 327                         dum->re_timeout = 0;
 328                 }
 329
 330                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 331                     0 && time_after(jiffies, dum->re_timeout)) {
 332                         dum->port_status[rhport] |=
 333                                 (1 << USB_PORT_FEAT_C_RESET);
 334                         dum->port_status[rhport] &=
 335                                 ~(1 << USB_PORT_FEAT_RESET);
 336                         dum->re_timeout = 0;
 337
 338                         if (dum->vdev[rhport].ud.status ==
 339                             VDEV_ST_NOTASSIGNED) {
 340                                 usbip_dbg_vhci_rh(
 341                                         " enable rhport %d (status %u)\n",
 342                                         rhport,
 343                                         dum->vdev[rhport].ud.status);
 344                                 dum->port_status[rhport] |=
 345                                         USB_PORT_STAT_ENABLE;
 346                         }
 347                 }
 348                 ((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 349                 ((__le16 *) buf)[1] =
 350                         cpu_to_le16(dum->port_status[rhport] >> 16);
 351
 352                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 353                                   ((u16 *)buf)[1]);
 354                 break;
 355         case SetHubFeature:
 356                 usbip_dbg_vhci_rh(" SetHubFeature\n");
 357                 retval = -EPIPE;
 358                 break;
 359         case SetPortFeature:
 360                 switch (wValue) {
 361                 case USB_PORT_FEAT_SUSPEND:
 362                         usbip_dbg_vhci_rh(
 363                                 " SetPortFeature: USB_PORT_FEAT_SUSPEND\n");
 364                         break;
 365                 case USB_PORT_FEAT_RESET:
 366                         usbip_dbg_vhci_rh(
 367                                 " SetPortFeature: USB_PORT_FEAT_RESET\n");
 368                         /* if it's already running, disconnect first */
 369                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 370                                 dum->port_status[rhport] &=
 371                                         ~(USB_PORT_STAT_ENABLE |
 372                                           USB_PORT_STAT_LOW_SPEED |
 373                                           USB_PORT_STAT_HIGH_SPEED);
 374                                 /* FIXME test that code path! */
 375                         }
 376                         /* 50msec reset signaling */
 377                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
 378
 379                         /* FALLTHROUGH */
 380                 default:
 381                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 382                                           wValue);
 383                         dum->port_status[rhport] |= (1 << wValue);
 384                         break;
 385                 }
 386                 break;
 387
 388         default:
 389                 pr_err("default: no such request\n");
 390
 391                 /* "protocol stall" on error */
 392                 retval = -EPIPE;
 393         }
 394
 395         if (usbip_dbg_flag_vhci_rh) {
 396                 pr_debug("port %d\n", rhport);
 397                 /* Only dump valid port status */
 398                 if (rhport >= 0) {
 399                         dump_port_status_diff(prev_port_status[rhport],
 400                                               dum->port_status[rhport]);
 401                 }
 402         }
 403         usbip_dbg_vhci_rh(" bye\n");
 404
 405         spin_unlock(&dum->lock);
 406
 407         return retval;
 408 }
 409
 410 static struct vhci_device *get_vdev(struct usb_device *udev)
 411 {
 412         int i;
 413
 414         if (!udev)
 415                 return NULL;
 416
 417         for (i = 0; i < VHCI_NPORTS; i++)
 418                 if (the_controller->vdev[i].udev == udev)
 419                         return port_to_vdev(i);
 420
 421         return NULL;
 422 }
 423
 424 static void vhci_tx_urb(struct urb *urb)
 425 {
 426         struct vhci_device *vdev = get_vdev(urb->dev);
 427         struct vhci_priv *priv;
 428
 429         if (!vdev) {
 430                 pr_err("could not get virtual device");
 431                 return;
 432         }
 433
 434         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 435         if (!priv) {
 436                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 437                 return;
 438         }
 439
 440         spin_lock(&vdev->priv_lock);
 441
 442         priv->seqnum = atomic_inc_return(&the_controller->seqnum);
 443         if (priv->seqnum == 0xffff)
 444                 dev_info(&urb->dev->dev, "seqnum max\n");
 445
 446         priv->vdev = vdev;
 447         priv->urb = urb;
 448
 449         urb->hcpriv = (void *) priv;
 450
 451         list_add_tail(&priv->list, &vdev->priv_tx);
 452
 453         wake_up(&vdev->waitq_tx);
 454         spin_unlock(&vdev->priv_lock);
 455 }
 456
 457 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 458                             gfp_t mem_flags)
 459 {
 460         struct device *dev = &urb->dev->dev;
 461         int ret = 0;
 462         struct vhci_device *vdev;
 463
 464         usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
 465                           hcd, urb, mem_flags);
 466
 467         /* patch to usb_sg_init() is in 2.5.60 */
 468         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 469
 470         spin_lock(&the_controller->lock);
 471
 472         if (urb->status != -EINPROGRESS) {
 473                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 474                 spin_unlock(&the_controller->lock);
 475                 return urb->status;
 476         }
 477
 478         vdev = port_to_vdev(urb->dev->portnum-1);
 479
 480         /* refuse enqueue for dead connection */
 481         spin_lock(&vdev->ud.lock);
 482         if (vdev->ud.status == VDEV_ST_NULL ||
 483             vdev->ud.status == VDEV_ST_ERROR) {
 484                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 485                 spin_unlock(&vdev->ud.lock);
 486                 spin_unlock(&the_controller->lock);
 487                 return -ENODEV;
 488         }
 489         spin_unlock(&vdev->ud.lock);
 490
 491         ret = usb_hcd_link_urb_to_ep(hcd, urb);
 492         if (ret)
 493                 goto no_need_unlink;
 494
 495         /*
 496          * The enumeration process is as follows;
 497          *
 498          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 499          *     to get max packet length of default pipe
 500          *
 501          *  2. Set_Address request to DevAddr(0) EndPoint(0)
 502          *
 503          */
 504         if (usb_pipedevice(urb->pipe) == 0) {
 505                 __u8 type = usb_pipetype(urb->pipe);
 506                 struct usb_ctrlrequest *ctrlreq =
 507                         (struct usb_ctrlrequest *) urb->setup_packet;
 508
 509                 if (type != PIPE_CONTROL || !ctrlreq) {
 510                         dev_err(dev, "invalid request to devnum 0\n");
 511                         ret = -EINVAL;
 512                         goto no_need_xmit;
 513                 }
 514
 515                 switch (ctrlreq->bRequest) {
 516                 case USB_REQ_SET_ADDRESS:
 517                         /* set_address may come when a device is reset */
 518                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
 519                                  ctrlreq->wValue, vdev->rhport);
 520
 521                         usb_put_dev(vdev->udev);
 522                         vdev->udev = usb_get_dev(urb->dev);
 523
 524                         spin_lock(&vdev->ud.lock);
 525                         vdev->ud.status = VDEV_ST_USED;
 526                         spin_unlock(&vdev->ud.lock);
 527
 528                         if (urb->status == -EINPROGRESS) {
 529                                 /* This request is successfully completed. */
 530                                 /* If not -EINPROGRESS, possibly unlinked. */
 531                                 urb->status = 0;
 532                         }
 533
 534                         goto no_need_xmit;
 535
 536                 case USB_REQ_GET_DESCRIPTOR:
 537                         if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
 538                                 usbip_dbg_vhci_hc(
 539                                         "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
 540
 541                         usb_put_dev(vdev->udev);
 542                         vdev->udev = usb_get_dev(urb->dev);
 543                         goto out;
 544
 545                 default:
 546                         /* NOT REACHED */
 547                         dev_err(dev,
 548                                 "invalid request to devnum 0 bRequest %u, wValue %u\n",
 549                                 ctrlreq->bRequest,
 550                                 ctrlreq->wValue);
 551                         ret =  -EINVAL;
 552                         goto no_need_xmit;
 553                 }
 554
 555         }
 556
 557 out:
 558         vhci_tx_urb(urb);
 559         spin_unlock(&the_controller->lock);
 560
 561         return 0;
 562
 563 no_need_xmit:
 564         usb_hcd_unlink_urb_from_ep(hcd, urb);
 565 no_need_unlink:
 566         spin_unlock(&the_controller->lock);
 567         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 568         return ret;
 569 }
 570
 571 /*
 572  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 573  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 574  * back its urb. For the driver unlinking the urb, the content of the urb is
 575  * not important, but the calling to its completion handler is important; the
 576  * completion of unlinking is notified by the completion handler.
 577  *
 578  *
 579  * CLIENT SIDE
 580  *
 581  * - When vhci_hcd receives RET_SUBMIT,
 582  *
 583  *      - case 1a). the urb of the pdu is not unlinking.
 584  *              - normal case
 585  *              => just give back the urb
 586  *
 587  *      - case 1b). the urb of the pdu is unlinking.
 588  *              - usbip.ko will return a reply of the unlinking request.
 589  *              => give back the urb now and go to case 2b).
 590  *
 591  * - When vhci_hcd receives RET_UNLINK,
 592  *
 593  *      - case 2a). a submit request is still pending in vhci_hcd.
 594  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 595  *                completed there.
 596  *              => free a pending submit request
 597  *              => notify unlink completeness by giving back the urb
 598  *
 599  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 600  *              - urb was already given back to the core driver.
 601  *              => do not give back the urb
 602  *
 603  *
 604  * SERVER SIDE
 605  *
 606  * - When usbip receives CMD_UNLINK,
 607  *
 608  *      - case 3a). the urb of the unlink request is now in submission.
 609  *              => do usb_unlink_urb().
 610  *              => after the unlink is completed, send RET_UNLINK.
 611  *
 612  *      - case 3b). the urb of the unlink request is not in submission.
 613  *              - may be already completed or never be received
 614  *              => send RET_UNLINK
 615  *
 616  */
 617 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 618 {
 619         struct vhci_priv *priv;
 620         struct vhci_device *vdev;
 621
 622         pr_info("dequeue a urb %p\n", urb);
 623
 624         spin_lock(&the_controller->lock);
 625
 626         priv = urb->hcpriv;
 627         if (!priv) {
 628                 /* URB was never linked! or will be soon given back by
 629                  * vhci_rx. */
 630                 spin_unlock(&the_controller->lock);
 631                 return 0;
 632         }
 633
 634         {
 635                 int ret = 0;
 636
 637                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 638                 if (ret) {
 639                         spin_unlock(&the_controller->lock);
 640                         return ret;
 641                 }
 642         }
 643
 644          /* send unlink request here? */
 645         vdev = priv->vdev;
 646
 647         if (!vdev->ud.tcp_socket) {
 648                 /* tcp connection is closed */
 649                 spin_lock(&vdev->priv_lock);
 650
 651                 pr_info("device %p seems to be disconnected\n", vdev);
 652                 list_del(&priv->list);
 653                 kfree(priv);
 654                 urb->hcpriv = NULL;
 655
 656                 spin_unlock(&vdev->priv_lock);
 657
 658                 /*
 659                  * If tcp connection is alive, we have sent CMD_UNLINK.
 660                  * vhci_rx will receive RET_UNLINK and give back the URB.
 661                  * Otherwise, we give back it here.
 662                  */
 663                 pr_info("gives back urb %p\n", urb);
 664
 665                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 666
 667                 spin_unlock(&the_controller->lock);
 668                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 669                                      urb->status);
 670                 spin_lock(&the_controller->lock);
 671
 672         } else {
 673                 /* tcp connection is alive */
 674                 struct vhci_unlink *unlink;
 675
 676                 spin_lock(&vdev->priv_lock);
 677
 678                 /* setup CMD_UNLINK pdu */
 679                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 680                 if (!unlink) {
 681                         spin_unlock(&vdev->priv_lock);
 682                         spin_unlock(&the_controller->lock);
 683                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 684                         return -ENOMEM;
 685                 }
 686
 687                 unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
 688                 if (unlink->seqnum == 0xffff)
 689                         pr_info("seqnum max\n");
 690
 691                 unlink->unlink_seqnum = priv->seqnum;
 692
 693                 pr_info("device %p seems to be still connected\n", vdev);
 694
 695                 /* send cmd_unlink and try to cancel the pending URB in the
 696                  * peer */
 697                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 698                 wake_up(&vdev->waitq_tx);
 699
 700                 spin_unlock(&vdev->priv_lock);
 701         }
 702
 703         spin_unlock(&the_controller->lock);
 704
 705         usbip_dbg_vhci_hc("leave\n");
 706         return 0;
 707 }
 708
 709 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 710 {
 711         struct vhci_unlink *unlink, *tmp;
 712
 713         spin_lock(&the_controller->lock);
 714         spin_lock(&vdev->priv_lock);
 715
 716         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 717                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 718                 list_del(&unlink->list);
 719                 kfree(unlink);
 720         }
 721
 722         while (!list_empty(&vdev->unlink_rx)) {
 723                 struct urb *urb;
 724
 725                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 726                         list);
 727
 728                 /* give back URB of unanswered unlink request */
 729                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 730
 731                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 732                 if (!urb) {
 733                         pr_info("the urb (seqnum %lu) was already given back\n",
 734                                 unlink->unlink_seqnum);
 735                         list_del(&unlink->list);
 736                         kfree(unlink);
 737                         continue;
 738                 }
 739
 740                 urb->status = -ENODEV;
 741
 742                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 743
 744                 list_del(&unlink->list);
 745
 746                 spin_unlock(&vdev->priv_lock);
 747                 spin_unlock(&the_controller->lock);
 748
 749                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 750                                      urb->status);
 751
 752                 spin_lock(&the_controller->lock);
 753                 spin_lock(&vdev->priv_lock);
 754
 755                 kfree(unlink);
 756         }
 757
 758         spin_unlock(&vdev->priv_lock);
 759         spin_unlock(&the_controller->lock);
 760 }
 761
 762 /*
 763  * The important thing is that only one context begins cleanup.
 764  * This is why error handling and cleanup become simple.
 765  * We do not want to consider race condition as possible.
 766  */
 767 static void vhci_shutdown_connection(struct usbip_device *ud)
 768 {
 769         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 770
 771         /* need this? see stub_dev.c */
 772         if (ud->tcp_socket) {
 773                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 774                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 775         }
 776
 777         /* kill threads related to this sdev */
 778         if (vdev->ud.tcp_rx) {
 779                 kthread_stop_put(vdev->ud.tcp_rx);
 780                 vdev->ud.tcp_rx = NULL;
 781         }
 782         if (vdev->ud.tcp_tx) {
 783                 kthread_stop_put(vdev->ud.tcp_tx);
 784                 vdev->ud.tcp_tx = NULL;
 785         }
 786         pr_info("stop threads\n");
 787
 788         /* active connection is closed */
 789         if (vdev->ud.tcp_socket) {
 790                 sockfd_put(vdev->ud.tcp_socket);
 791                 vdev->ud.tcp_socket = NULL;
 792         }
 793         pr_info("release socket\n");
 794
 795         vhci_device_unlink_cleanup(vdev);
 796
 797         /*
 798          * rh_port_disconnect() is a trigger of ...
 799          *   usb_disable_device():
 800          *      disable all the endpoints for a USB device.
 801          *   usb_disable_endpoint():
 802          *      disable endpoints. pending urbs are unlinked(dequeued).
 803          *
 804          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 805          * detached device should release used urbs in a cleanup function (i.e.
 806          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 807          * pushed urbs and their private data in this function.
 808          *
 809          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 810          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 811          * gives back pushed urbs and frees their private data by request of
 812          * the cleanup function of a USB driver. When unlinking a urb with an
 813          * active connection, vhci_dequeue() does not give back the urb which
 814          * is actually given back by vhci_rx after receiving its return pdu.
 815          *
 816          */
 817         rh_port_disconnect(vdev->rhport);
 818
 819         pr_info("disconnect device\n");
 820 }
 821
 822
 823 static void vhci_device_reset(struct usbip_device *ud)
 824 {
 825         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 826
 827         spin_lock(&ud->lock);
 828
 829         vdev->speed  = 0;
 830         vdev->devid  = 0;
 831
 832         usb_put_dev(vdev->udev);
 833         vdev->udev = NULL;
 834
 835         if (ud->tcp_socket) {
 836                 sockfd_put(ud->tcp_socket);
 837                 ud->tcp_socket = NULL;
 838         }
 839         ud->status = VDEV_ST_NULL;
 840
 841         spin_unlock(&ud->lock);
 842 }
 843
 844 static void vhci_device_unusable(struct usbip_device *ud)
 845 {
 846         spin_lock(&ud->lock);
 847         ud->status = VDEV_ST_ERROR;
 848         spin_unlock(&ud->lock);
 849 }
 850
 851 static void vhci_device_init(struct vhci_device *vdev)
 852 {
 853         memset(vdev, 0, sizeof(*vdev));
 854
 855         vdev->ud.side   = USBIP_VHCI;
 856         vdev->ud.status = VDEV_ST_NULL;
 857         spin_lock_init(&vdev->ud.lock);
 858
 859         INIT_LIST_HEAD(&vdev->priv_rx);
 860         INIT_LIST_HEAD(&vdev->priv_tx);
 861         INIT_LIST_HEAD(&vdev->unlink_tx);
 862         INIT_LIST_HEAD(&vdev->unlink_rx);
 863         spin_lock_init(&vdev->priv_lock);
 864
 865         init_waitqueue_head(&vdev->waitq_tx);
 866
 867         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 868         vdev->ud.eh_ops.reset = vhci_device_reset;
 869         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 870
 871         usbip_start_eh(&vdev->ud);
 872 }
 873
 874 static int vhci_start(struct usb_hcd *hcd)
 875 {
 876         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 877         int rhport;
 878         int err = 0;
 879
 880         usbip_dbg_vhci_hc("enter vhci_start\n");
 881
 882         /* initialize private data of usb_hcd */
 883
 884         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 885                 struct vhci_device *vdev = &vhci->vdev[rhport];
 886
 887                 vhci_device_init(vdev);
 888                 vdev->rhport = rhport;
 889         }
 890
 891         atomic_set(&vhci->seqnum, 0);
 892         spin_lock_init(&vhci->lock);
 893
 894         hcd->power_budget = 0; /* no limit */
 895         hcd->uses_new_polling = 1;
 896
 897         /* vhci_hcd is now ready to be controlled through sysfs */
 898         err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 899         if (err) {
 900                 pr_err("create sysfs files\n");
 901                 return err;
 902         }
 903
 904         return 0;
 905 }
 906
 907 static void vhci_stop(struct usb_hcd *hcd)
 908 {
 909         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 910         int rhport = 0;
 911
 912         usbip_dbg_vhci_hc("stop VHCI controller\n");
 913
 914         /* 1. remove the userland interface of vhci_hcd */
 915         sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 916
 917         /* 2. shutdown all the ports of vhci_hcd */
 918         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 919                 struct vhci_device *vdev = &vhci->vdev[rhport];
 920
 921                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
 922                 usbip_stop_eh(&vdev->ud);
 923         }
 924 }
 925
 926 static int vhci_get_frame_number(struct usb_hcd *hcd)
 927 {
 928         pr_err("Not yet implemented\n");
 929         return 0;
 930 }
 931
 932 #ifdef CONFIG_PM
 933
 934 /* FIXME: suspend/resume */
 935 static int vhci_bus_suspend(struct usb_hcd *hcd)
 936 {
 937         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 938
 939         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 940
 941         spin_lock(&vhci->lock);
 942         hcd->state = HC_STATE_SUSPENDED;
 943         spin_unlock(&vhci->lock);
 944
 945         return 0;
 946 }
 947
 948 static int vhci_bus_resume(struct usb_hcd *hcd)
 949 {
 950         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 951         int rc = 0;
 952
 953         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 954
 955         spin_lock(&vhci->lock);
 956         if (!HCD_HW_ACCESSIBLE(hcd))
 957                 rc = -ESHUTDOWN;
 958         else
 959                 hcd->state = HC_STATE_RUNNING;
 960         spin_unlock(&vhci->lock);
 961
 962         return rc;
 963 }
 964
 965 #else
 966
 967 #define vhci_bus_suspend      NULL
 968 #define vhci_bus_resume       NULL
 969 #endif
 970
 971 static struct hc_driver vhci_hc_driver = {
 972         .description    = driver_name,
 973         .product_desc   = driver_desc,
 974         .hcd_priv_size  = sizeof(struct vhci_hcd),
 975
 976         .flags          = HCD_USB2,
 977
 978         .start          = vhci_start,
 979         .stop           = vhci_stop,
 980
 981         .urb_enqueue    = vhci_urb_enqueue,
 982         .urb_dequeue    = vhci_urb_dequeue,
 983
 984         .get_frame_number = vhci_get_frame_number,
 985
 986         .hub_status_data = vhci_hub_status,
 987         .hub_control    = vhci_hub_control,
 988         .bus_suspend    = vhci_bus_suspend,
 989         .bus_resume     = vhci_bus_resume,
 990 };
 991
 992 static int vhci_hcd_probe(struct platform_device *pdev)
 993 {
 994         struct usb_hcd          *hcd;
 995         int                     ret;
 996
 997         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
 998
 999         /*
1000          * Allocate and initialize hcd.
1001          * Our private data is also allocated automatically.
1002          */
1003         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1004         if (!hcd) {
1005                 pr_err("create hcd failed\n");
1006                 return -ENOMEM;
1007         }
1008         hcd->has_tt = 1;
1009
1010         /* this is private data for vhci_hcd */
1011         the_controller = hcd_to_vhci(hcd);
1012
1013         /*
1014          * Finish generic HCD structure initialization and register.
1015          * Call the driver's reset() and start() routines.
1016          */
1017         ret = usb_add_hcd(hcd, 0, 0);
1018         if (ret != 0) {
1019                 pr_err("usb_add_hcd failed %d\n", ret);
1020                 usb_put_hcd(hcd);
1021                 the_controller = NULL;
1022                 return ret;
1023         }
1024
1025         usbip_dbg_vhci_hc("bye\n");
1026         return 0;
1027 }
1028
1029 static int vhci_hcd_remove(struct platform_device *pdev)
1030 {
1031         struct usb_hcd  *hcd;
1032
1033         hcd = platform_get_drvdata(pdev);
1034         if (!hcd)
1035                 return 0;
1036
1037         /*
1038          * Disconnects the root hub,
1039          * then reverses the effects of usb_add_hcd(),
1040          * invoking the HCD's stop() methods.
1041          */
1042         usb_remove_hcd(hcd);
1043         usb_put_hcd(hcd);
1044         the_controller = NULL;
1045
1046         return 0;
1047 }
1048
1049 #ifdef CONFIG_PM
1050
1051 /* what should happen for USB/IP under suspend/resume? */
1052 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1053 {
1054         struct usb_hcd *hcd;
1055         int rhport = 0;
1056         int connected = 0;
1057         int ret = 0;
1058
1059         hcd = platform_get_drvdata(pdev);
1060
1061         spin_lock(&the_controller->lock);
1062
1063         for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1064                 if (the_controller->port_status[rhport] &
1065                     USB_PORT_STAT_CONNECTION)
1066                         connected += 1;
1067
1068         spin_unlock(&the_controller->lock);
1069
1070         if (connected > 0) {
1071                 dev_info(&pdev->dev,
1072                          "We have %d active connection%s. Do not suspend.\n",
1073                          connected, (connected == 1 ? "" : "s"));
1074                 ret =  -EBUSY;
1075         } else {
1076                 dev_info(&pdev->dev, "suspend vhci_hcd");
1077                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1078         }
1079
1080         return ret;
1081 }
1082
1083 static int vhci_hcd_resume(struct platform_device *pdev)
1084 {
1085         struct usb_hcd *hcd;
1086
1087         dev_dbg(&pdev->dev, "%s\n", __func__);
1088
1089         hcd = platform_get_drvdata(pdev);
1090         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1091         usb_hcd_poll_rh_status(hcd);
1092
1093         return 0;
1094 }
1095
1096 #else
1097
1098 #define vhci_hcd_suspend        NULL
1099 #define vhci_hcd_resume         NULL
1100
1101 #endif
1102
1103 static struct platform_driver vhci_driver = {
1104         .probe  = vhci_hcd_probe,
1105         .remove = vhci_hcd_remove,
1106         .suspend = vhci_hcd_suspend,
1107         .resume = vhci_hcd_resume,
1108         .driver = {
1109                 .name = driver_name,
1110         },
1111 };
1112
1113 /*
1114  * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1115  * We need to add this virtual device as a platform device arbitrarily:
1116  *      1. platform_device_register()
1117  */
1118 static void the_pdev_release(struct device *dev)
1119 {
1120 }
1121
1122 static struct platform_device the_pdev = {
1123         /* should be the same name as driver_name */
1124         .name = driver_name,
1125         .id = -1,
1126         .dev = {
1127                 .release = the_pdev_release,
1128         },
1129 };
1130
1131 static int __init vhci_hcd_init(void)
1132 {
1133         int ret;
1134
1135         if (usb_disabled())
1136                 return -ENODEV;
1137
1138         ret = platform_driver_register(&vhci_driver);
1139         if (ret)
1140                 goto err_driver_register;
1141
1142         ret = platform_device_register(&the_pdev);
1143         if (ret)
1144                 goto err_platform_device_register;
1145
1146         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1147         return ret;
1148
1149 err_platform_device_register:
1150         platform_driver_unregister(&vhci_driver);
1151 err_driver_register:
1152         return ret;
1153 }
1154
1155 static void __exit vhci_hcd_exit(void)
1156 {
1157         platform_device_unregister(&the_pdev);
1158         platform_driver_unregister(&vhci_driver);
1159 }
1160
1161 module_init(vhci_hcd_init);
1162 module_exit(vhci_hcd_exit);
1163
1164 MODULE_AUTHOR(DRIVER_AUTHOR);
1165 MODULE_DESCRIPTION(DRIVER_DESC);
1166 MODULE_LICENSE("GPL");
1167 MODULE_VERSION(USBIP_VERSION);