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",           /*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 = __constant_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                         if (vdev->udev)
 522                                 usb_put_dev(vdev->udev);
 523                         vdev->udev = usb_get_dev(urb->dev);
 524
 525                         spin_lock(&vdev->ud.lock);
 526                         vdev->ud.status = VDEV_ST_USED;
 527                         spin_unlock(&vdev->ud.lock);
 528
 529                         if (urb->status == -EINPROGRESS) {
 530                                 /* This request is successfully completed. */
 531                                 /* If not -EINPROGRESS, possibly unlinked. */
 532                                 urb->status = 0;
 533                         }
 534
 535                         goto no_need_xmit;
 536
 537                 case USB_REQ_GET_DESCRIPTOR:
 538                         if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
 539                                 usbip_dbg_vhci_hc(
 540                                         "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
 541
 542                         if (vdev->udev)
 543                                 usb_put_dev(vdev->udev);
 544                         vdev->udev = usb_get_dev(urb->dev);
 545                         goto out;
 546
 547                 default:
 548                         /* NOT REACHED */
 549                         dev_err(dev,
 550                                 "invalid request to devnum 0 bRequest %u, wValue %u\n",
 551                                 ctrlreq->bRequest,
 552                                 ctrlreq->wValue);
 553                         ret =  -EINVAL;
 554                         goto no_need_xmit;
 555                 }
 556
 557         }
 558
 559 out:
 560         vhci_tx_urb(urb);
 561         spin_unlock(&the_controller->lock);
 562
 563         return 0;
 564
 565 no_need_xmit:
 566         usb_hcd_unlink_urb_from_ep(hcd, urb);
 567 no_need_unlink:
 568         spin_unlock(&the_controller->lock);
 569         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 570         return ret;
 571 }
 572
 573 /*
 574  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 575  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 576  * back its urb. For the driver unlinking the urb, the content of the urb is
 577  * not important, but the calling to its completion handler is important; the
 578  * completion of unlinking is notified by the completion handler.
 579  *
 580  *
 581  * CLIENT SIDE
 582  *
 583  * - When vhci_hcd receives RET_SUBMIT,
 584  *
 585  *      - case 1a). the urb of the pdu is not unlinking.
 586  *              - normal case
 587  *              => just give back the urb
 588  *
 589  *      - case 1b). the urb of the pdu is unlinking.
 590  *              - usbip.ko will return a reply of the unlinking request.
 591  *              => give back the urb now and go to case 2b).
 592  *
 593  * - When vhci_hcd receives RET_UNLINK,
 594  *
 595  *      - case 2a). a submit request is still pending in vhci_hcd.
 596  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 597  *                completed there.
 598  *              => free a pending submit request
 599  *              => notify unlink completeness by giving back the urb
 600  *
 601  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 602  *              - urb was already given back to the core driver.
 603  *              => do not give back the urb
 604  *
 605  *
 606  * SERVER SIDE
 607  *
 608  * - When usbip receives CMD_UNLINK,
 609  *
 610  *      - case 3a). the urb of the unlink request is now in submission.
 611  *              => do usb_unlink_urb().
 612  *              => after the unlink is completed, send RET_UNLINK.
 613  *
 614  *      - case 3b). the urb of the unlink request is not in submission.
 615  *              - may be already completed or never be received
 616  *              => send RET_UNLINK
 617  *
 618  */
 619 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 620 {
 621         struct vhci_priv *priv;
 622         struct vhci_device *vdev;
 623
 624         pr_info("dequeue a urb %p\n", urb);
 625
 626         spin_lock(&the_controller->lock);
 627
 628         priv = urb->hcpriv;
 629         if (!priv) {
 630                 /* URB was never linked! or will be soon given back by
 631                  * vhci_rx. */
 632                 spin_unlock(&the_controller->lock);
 633                 return 0;
 634         }
 635
 636         {
 637                 int ret = 0;
 638                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 639                 if (ret) {
 640                         spin_unlock(&the_controller->lock);
 641                         return ret;
 642                 }
 643         }
 644
 645          /* send unlink request here? */
 646         vdev = priv->vdev;
 647
 648         if (!vdev->ud.tcp_socket) {
 649                 /* tcp connection is closed */
 650                 spin_lock(&vdev->priv_lock);
 651
 652                 pr_info("device %p seems to be disconnected\n", vdev);
 653                 list_del(&priv->list);
 654                 kfree(priv);
 655                 urb->hcpriv = NULL;
 656
 657                 spin_unlock(&vdev->priv_lock);
 658
 659                 /*
 660                  * If tcp connection is alive, we have sent CMD_UNLINK.
 661                  * vhci_rx will receive RET_UNLINK and give back the URB.
 662                  * Otherwise, we give back it here.
 663                  */
 664                 pr_info("gives back urb %p\n", urb);
 665
 666                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 667
 668                 spin_unlock(&the_controller->lock);
 669                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 670                                      urb->status);
 671                 spin_lock(&the_controller->lock);
 672
 673         } else {
 674                 /* tcp connection is alive */
 675                 struct vhci_unlink *unlink;
 676
 677                 spin_lock(&vdev->priv_lock);
 678
 679                 /* setup CMD_UNLINK pdu */
 680                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 681                 if (!unlink) {
 682                         spin_unlock(&vdev->priv_lock);
 683                         spin_unlock(&the_controller->lock);
 684                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 685                         return -ENOMEM;
 686                 }
 687
 688                 unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
 689                 if (unlink->seqnum == 0xffff)
 690                         pr_info("seqnum max\n");
 691
 692                 unlink->unlink_seqnum = priv->seqnum;
 693
 694                 pr_info("device %p seems to be still connected\n", vdev);
 695
 696                 /* send cmd_unlink and try to cancel the pending URB in the
 697                  * peer */
 698                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 699                 wake_up(&vdev->waitq_tx);
 700
 701                 spin_unlock(&vdev->priv_lock);
 702         }
 703
 704         spin_unlock(&the_controller->lock);
 705
 706         usbip_dbg_vhci_hc("leave\n");
 707         return 0;
 708 }
 709
 710 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 711 {
 712         struct vhci_unlink *unlink, *tmp;
 713
 714         spin_lock(&the_controller->lock);
 715         spin_lock(&vdev->priv_lock);
 716
 717         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 718                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 719                 list_del(&unlink->list);
 720                 kfree(unlink);
 721         }
 722
 723         while (!list_empty(&vdev->unlink_rx)) {
 724                 struct urb *urb;
 725
 726                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 727                         list);
 728
 729                 /* give back URB of unanswered unlink request */
 730                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 731
 732                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 733                 if (!urb) {
 734                         pr_info("the urb (seqnum %lu) was already given back\n",
 735                                 unlink->unlink_seqnum);
 736                         list_del(&unlink->list);
 737                         kfree(unlink);
 738                         continue;
 739                 }
 740
 741                 urb->status = -ENODEV;
 742
 743                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 744
 745                 list_del(&unlink->list);
 746
 747                 spin_unlock(&vdev->priv_lock);
 748                 spin_unlock(&the_controller->lock);
 749
 750                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 751                                      urb->status);
 752
 753                 spin_lock(&the_controller->lock);
 754                 spin_lock(&vdev->priv_lock);
 755
 756                 kfree(unlink);
 757         }
 758
 759         spin_unlock(&vdev->priv_lock);
 760         spin_unlock(&the_controller->lock);
 761 }
 762
 763 /*
 764  * The important thing is that only one context begins cleanup.
 765  * This is why error handling and cleanup become simple.
 766  * We do not want to consider race condition as possible.
 767  */
 768 static void vhci_shutdown_connection(struct usbip_device *ud)
 769 {
 770         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 771
 772         /* need this? see stub_dev.c */
 773         if (ud->tcp_socket) {
 774                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 775                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 776         }
 777
 778         /* kill threads related to this sdev */
 779         if (vdev->ud.tcp_rx) {
 780                 kthread_stop_put(vdev->ud.tcp_rx);
 781                 vdev->ud.tcp_rx = NULL;
 782         }
 783         if (vdev->ud.tcp_tx) {
 784                 kthread_stop_put(vdev->ud.tcp_tx);
 785                 vdev->ud.tcp_tx = NULL;
 786         }
 787         pr_info("stop threads\n");
 788
 789         /* active connection is closed */
 790         if (vdev->ud.tcp_socket) {
 791                 sockfd_put(vdev->ud.tcp_socket);
 792                 vdev->ud.tcp_socket = NULL;
 793         }
 794         pr_info("release socket\n");
 795
 796         vhci_device_unlink_cleanup(vdev);
 797
 798         /*
 799          * rh_port_disconnect() is a trigger of ...
 800          *   usb_disable_device():
 801          *      disable all the endpoints for a USB device.
 802          *   usb_disable_endpoint():
 803          *      disable endpoints. pending urbs are unlinked(dequeued).
 804          *
 805          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 806          * detached device should release used urbs in a cleanup function (i.e.
 807          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 808          * pushed urbs and their private data in this function.
 809          *
 810          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 811          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 812          * gives back pushed urbs and frees their private data by request of
 813          * the cleanup function of a USB driver. When unlinking a urb with an
 814          * active connection, vhci_dequeue() does not give back the urb which
 815          * is actually given back by vhci_rx after receiving its return pdu.
 816          *
 817          */
 818         rh_port_disconnect(vdev->rhport);
 819
 820         pr_info("disconnect device\n");
 821 }
 822
 823
 824 static void vhci_device_reset(struct usbip_device *ud)
 825 {
 826         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 827
 828         spin_lock(&ud->lock);
 829
 830         vdev->speed  = 0;
 831         vdev->devid  = 0;
 832
 833         if (vdev->udev)
 834                 usb_put_dev(vdev->udev);
 835         vdev->udev = NULL;
 836
 837         if (ud->tcp_socket) {
 838                 sockfd_put(ud->tcp_socket);
 839                 ud->tcp_socket = NULL;
 840         }
 841         ud->status = VDEV_ST_NULL;
 842
 843         spin_unlock(&ud->lock);
 844 }
 845
 846 static void vhci_device_unusable(struct usbip_device *ud)
 847 {
 848         spin_lock(&ud->lock);
 849         ud->status = VDEV_ST_ERROR;
 850         spin_unlock(&ud->lock);
 851 }
 852
 853 static void vhci_device_init(struct vhci_device *vdev)
 854 {
 855         memset(vdev, 0, sizeof(*vdev));
 856
 857         vdev->ud.side   = USBIP_VHCI;
 858         vdev->ud.status = VDEV_ST_NULL;
 859         spin_lock_init(&vdev->ud.lock);
 860
 861         INIT_LIST_HEAD(&vdev->priv_rx);
 862         INIT_LIST_HEAD(&vdev->priv_tx);
 863         INIT_LIST_HEAD(&vdev->unlink_tx);
 864         INIT_LIST_HEAD(&vdev->unlink_rx);
 865         spin_lock_init(&vdev->priv_lock);
 866
 867         init_waitqueue_head(&vdev->waitq_tx);
 868
 869         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 870         vdev->ud.eh_ops.reset = vhci_device_reset;
 871         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 872
 873         usbip_start_eh(&vdev->ud);
 874 }
 875
 876 static int vhci_start(struct usb_hcd *hcd)
 877 {
 878         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 879         int rhport;
 880         int err = 0;
 881
 882         usbip_dbg_vhci_hc("enter vhci_start\n");
 883
 884         /* initialize private data of usb_hcd */
 885
 886         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 887                 struct vhci_device *vdev = &vhci->vdev[rhport];
 888                 vhci_device_init(vdev);
 889                 vdev->rhport = rhport;
 890         }
 891
 892         atomic_set(&vhci->seqnum, 0);
 893         spin_lock_init(&vhci->lock);
 894
 895         hcd->power_budget = 0; /* no limit */
 896         hcd->uses_new_polling = 1;
 897
 898         /* vhci_hcd is now ready to be controlled through sysfs */
 899         err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 900         if (err) {
 901                 pr_err("create sysfs files\n");
 902                 return err;
 903         }
 904
 905         return 0;
 906 }
 907
 908 static void vhci_stop(struct usb_hcd *hcd)
 909 {
 910         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 911         int rhport = 0;
 912
 913         usbip_dbg_vhci_hc("stop VHCI controller\n");
 914
 915         /* 1. remove the userland interface of vhci_hcd */
 916         sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 917
 918         /* 2. shutdown all the ports of vhci_hcd */
 919         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 920                 struct vhci_device *vdev = &vhci->vdev[rhport];
 921
 922                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
 923                 usbip_stop_eh(&vdev->ud);
 924         }
 925 }
 926
 927 static int vhci_get_frame_number(struct usb_hcd *hcd)
 928 {
 929         pr_err("Not yet implemented\n");
 930         return 0;
 931 }
 932
 933 #ifdef CONFIG_PM
 934
 935 /* FIXME: suspend/resume */
 936 static int vhci_bus_suspend(struct usb_hcd *hcd)
 937 {
 938         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 939
 940         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 941
 942         spin_lock(&vhci->lock);
 943         hcd->state = HC_STATE_SUSPENDED;
 944         spin_unlock(&vhci->lock);
 945
 946         return 0;
 947 }
 948
 949 static int vhci_bus_resume(struct usb_hcd *hcd)
 950 {
 951         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 952         int rc = 0;
 953
 954         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 955
 956         spin_lock(&vhci->lock);
 957         if (!HCD_HW_ACCESSIBLE(hcd))
 958                 rc = -ESHUTDOWN;
 959         else
 960                 hcd->state = HC_STATE_RUNNING;
 961         spin_unlock(&vhci->lock);
 962
 963         return rc;
 964 }
 965
 966 #else
 967
 968 #define vhci_bus_suspend      NULL
 969 #define vhci_bus_resume       NULL
 970 #endif
 971
 972 static struct hc_driver vhci_hc_driver = {
 973         .description    = driver_name,
 974         .product_desc   = driver_desc,
 975         .hcd_priv_size  = sizeof(struct vhci_hcd),
 976
 977         .flags          = HCD_USB2,
 978
 979         .start          = vhci_start,
 980         .stop           = vhci_stop,
 981
 982         .urb_enqueue    = vhci_urb_enqueue,
 983         .urb_dequeue    = vhci_urb_dequeue,
 984
 985         .get_frame_number = vhci_get_frame_number,
 986
 987         .hub_status_data = vhci_hub_status,
 988         .hub_control    = vhci_hub_control,
 989         .bus_suspend    = vhci_bus_suspend,
 990         .bus_resume     = vhci_bus_resume,
 991 };
 992
 993 static int vhci_hcd_probe(struct platform_device *pdev)
 994 {
 995         struct usb_hcd          *hcd;
 996         int                     ret;
 997
 998         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
 999
1000         /*
1001          * Allocate and initialize hcd.
1002          * Our private data is also allocated automatically.
1003          */
1004         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1005         if (!hcd) {
1006                 pr_err("create hcd failed\n");
1007                 return -ENOMEM;
1008         }
1009         hcd->has_tt = 1;
1010
1011         /* this is private data for vhci_hcd */
1012         the_controller = hcd_to_vhci(hcd);
1013
1014         /*
1015          * Finish generic HCD structure initialization and register.
1016          * Call the driver's reset() and start() routines.
1017          */
1018         ret = usb_add_hcd(hcd, 0, 0);
1019         if (ret != 0) {
1020                 pr_err("usb_add_hcd failed %d\n", ret);
1021                 usb_put_hcd(hcd);
1022                 the_controller = NULL;
1023                 return ret;
1024         }
1025
1026         usbip_dbg_vhci_hc("bye\n");
1027         return 0;
1028 }
1029
1030 static int vhci_hcd_remove(struct platform_device *pdev)
1031 {
1032         struct usb_hcd  *hcd;
1033
1034         hcd = platform_get_drvdata(pdev);
1035         if (!hcd)
1036                 return 0;
1037
1038         /*
1039          * Disconnects the root hub,
1040          * then reverses the effects of usb_add_hcd(),
1041          * invoking the HCD's stop() methods.
1042          */
1043         usb_remove_hcd(hcd);
1044         usb_put_hcd(hcd);
1045         the_controller = NULL;
1046
1047         return 0;
1048 }
1049
1050 #ifdef CONFIG_PM
1051
1052 /* what should happen for USB/IP under suspend/resume? */
1053 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1054 {
1055         struct usb_hcd *hcd;
1056         int rhport = 0;
1057         int connected = 0;
1058         int ret = 0;
1059
1060         hcd = platform_get_drvdata(pdev);
1061
1062         spin_lock(&the_controller->lock);
1063
1064         for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1065                 if (the_controller->port_status[rhport] &
1066                     USB_PORT_STAT_CONNECTION)
1067                         connected += 1;
1068
1069         spin_unlock(&the_controller->lock);
1070
1071         if (connected > 0) {
1072                 dev_info(&pdev->dev,
1073                          "We have %d active connection%s. Do not suspend.\n",
1074                          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);