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/kernel.h>
  22 #include <linux/kthread.h>
  23 #include <linux/module.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/slab.h>
  26
  27 #include "usbip_common.h"
  28 #include "vhci.h"
  29
  30 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
  31 #define DRIVER_DESC "USB/IP 'Virtual' Host Controller (VHCI) Driver"
  32
  33 /*
  34  * TODO
  35  *      - update root hub emulation
  36  *      - move the emulation code to userland ?
  37  *              porting to other operating systems
  38  *              minimize kernel code
  39  *      - add suspend/resume code
  40  *      - clean up everything
  41  */
  42
  43 /* See usb gadget dummy hcd */
  44
  45 static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
  46 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
  47                             u16 wIndex, char *buff, u16 wLength);
  48 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
  49                             gfp_t mem_flags);
  50 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
  51 static int vhci_start(struct usb_hcd *vhci_hcd);
  52 static void vhci_stop(struct usb_hcd *hcd);
  53 static int vhci_get_frame_number(struct usb_hcd *hcd);
  54
  55 static const char driver_name[] = "vhci_hcd";
  56 static const char driver_desc[] = "USB/IP Virtual Host Controller";
  57
  58 struct vhci_hcd *the_controller;
  59
  60 static const char * const bit_desc[] = {
  61         "CONNECTION",           /*0*/
  62         "ENABLE",               /*1*/
  63         "SUSPEND",              /*2*/
  64         "OVER_CURRENT",         /*3*/
  65         "RESET",                /*4*/
  66         "R5",                   /*5*/
  67         "R6",                   /*6*/
  68         "R7",                   /*7*/
  69         "POWER",                /*8*/
  70         "LOWSPEED",             /*9*/
  71         "HIGHSPEED",            /*10*/
  72         "PORT_TEST",            /*11*/
  73         "INDICATOR",            /*12*/
  74         "R13",                  /*13*/
  75         "R14",                  /*14*/
  76         "R15",                  /*15*/
  77         "C_CONNECTION",         /*16*/
  78         "C_ENABLE",             /*17*/
  79         "C_SUSPEND",            /*18*/
  80         "C_OVER_CURRENT",       /*19*/
  81         "C_RESET",              /*20*/
  82         "R21",                  /*21*/
  83         "R22",                  /*22*/
  84         "R23",                  /*23*/
  85         "R24",                  /*24*/
  86         "R25",                  /*25*/
  87         "R26",                  /*26*/
  88         "R27",                  /*27*/
  89         "R28",                  /*28*/
  90         "R29",                  /*29*/
  91         "R30",                  /*30*/
  92         "R31",                  /*31*/
  93 };
  94
  95 static void dump_port_status_diff(u32 prev_status, u32 new_status)
  96 {
  97         int i = 0;
  98         u32 bit = 1;
  99
 100         pr_debug("status prev -> new: %08x -> %08x\n", prev_status, new_status);
 101         while (bit) {
 102                 u32 prev = prev_status & bit;
 103                 u32 new = new_status & bit;
 104                 char change;
 105
 106                 if (!prev && new)
 107                         change = '+';
 108                 else if (prev && !new)
 109                         change = '-';
 110                 else
 111                         change = ' ';
 112
 113                 if (prev || new)
 114                         pr_debug(" %c%s\n", change, bit_desc[i]);
 115                 bit <<= 1;
 116                 i++;
 117         }
 118         pr_debug("\n");
 119 }
 120
 121 void rh_port_connect(int rhport, enum usb_device_speed speed)
 122 {
 123         unsigned long   flags;
 124
 125         usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
 126
 127         spin_lock_irqsave(&the_controller->lock, flags);
 128
 129         the_controller->port_status[rhport] |= USB_PORT_STAT_CONNECTION
 130                 | (1 << USB_PORT_FEAT_C_CONNECTION);
 131
 132         switch (speed) {
 133         case USB_SPEED_HIGH:
 134                 the_controller->port_status[rhport] |= USB_PORT_STAT_HIGH_SPEED;
 135                 break;
 136         case USB_SPEED_LOW:
 137                 the_controller->port_status[rhport] |= USB_PORT_STAT_LOW_SPEED;
 138                 break;
 139         default:
 140                 break;
 141         }
 142
 143         /* spin_lock(&the_controller->vdev[rhport].ud.lock);
 144          * the_controller->vdev[rhport].ud.status = VDEV_CONNECT;
 145          * spin_unlock(&the_controller->vdev[rhport].ud.lock); */
 146
 147         spin_unlock_irqrestore(&the_controller->lock, flags);
 148
 149         usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
 150 }
 151
 152 void rh_port_disconnect(int rhport)
 153 {
 154         unsigned long flags;
 155
 156         usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
 157
 158         spin_lock_irqsave(&the_controller->lock, flags);
 159         /* stop_activity(dum, driver); */
 160         the_controller->port_status[rhport] &= ~USB_PORT_STAT_CONNECTION;
 161         the_controller->port_status[rhport] |=
 162                                         (1 << USB_PORT_FEAT_C_CONNECTION);
 163
 164         /* not yet complete the disconnection
 165          * spin_lock(&vdev->ud.lock);
 166          * vdev->ud.status = VHC_ST_DISCONNECT;
 167          * spin_unlock(&vdev->ud.lock); */
 168
 169         spin_unlock_irqrestore(&the_controller->lock, flags);
 170         usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
 171 }
 172
 173 #define PORT_C_MASK                             \
 174         ((USB_PORT_STAT_C_CONNECTION            \
 175           | USB_PORT_STAT_C_ENABLE              \
 176           | USB_PORT_STAT_C_SUSPEND             \
 177           | USB_PORT_STAT_C_OVERCURRENT         \
 178           | USB_PORT_STAT_C_RESET) << 16)
 179
 180 /*
 181  * This function is almostly the same as dummy_hcd.c:dummy_hub_status() without
 182  * suspend/resume support. But, it is modified to provide multiple ports.
 183  *
 184  * @buf: a bitmap to show which port status has been changed.
 185  *  bit  0: reserved or used for another purpose?
 186  *  bit  1: the status of port 0 has been changed.
 187  *  bit  2: the status of port 1 has been changed.
 188  *  ...
 189  *  bit  7: the status of port 6 has been changed.
 190  *  bit  8: the status of port 7 has been changed.
 191  *  ...
 192  *  bit 15: the status of port 14 has been changed.
 193  *
 194  * So, the maximum number of ports is 31 ( port 0 to port 30) ?
 195  *
 196  * The return value is the actual transferred length in byte. If nothing has
 197  * been changed, return 0. In the case that the number of ports is less than or
 198  * equal to 6 (VHCI_NPORTS==7), return 1.
 199  *
 200  */
 201 static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
 202 {
 203         struct vhci_hcd *vhci;
 204         unsigned long   flags;
 205         int             retval = 0;
 206
 207         /* the enough buffer is allocated according to USB_MAXCHILDREN */
 208         unsigned long   *event_bits = (unsigned long *) buf;
 209         int             rhport;
 210         int             changed = 0;
 211
 212         *event_bits = 0;
 213
 214         vhci = hcd_to_vhci(hcd);
 215
 216         spin_lock_irqsave(&vhci->lock, flags);
 217         if (!HCD_HW_ACCESSIBLE(hcd)) {
 218                 usbip_dbg_vhci_rh("hw accessible flag in on?\n");
 219                 goto done;
 220         }
 221
 222         /* check pseudo status register for each port */
 223         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 224                 if ((vhci->port_status[rhport] & PORT_C_MASK)) {
 225                         /* The status of a port has been changed, */
 226                         usbip_dbg_vhci_rh("port %d is changed\n", rhport);
 227
 228                         *event_bits |= 1 << (rhport + 1);
 229                         changed = 1;
 230                 }
 231         }
 232
 233         pr_info("changed %d\n", changed);
 234
 235         if (hcd->state == HC_STATE_SUSPENDED)
 236                 usb_hcd_resume_root_hub(hcd);
 237
 238         if (changed)
 239                 retval = 1 + (VHCI_NPORTS / 8);
 240         else
 241                 retval = 0;
 242
 243 done:
 244         spin_unlock_irqrestore(&vhci->lock, flags);
 245         return retval;
 246 }
 247
 248 /* See hub_configure in hub.c */
 249 static inline void hub_descriptor(struct usb_hub_descriptor *desc)
 250 {
 251         memset(desc, 0, sizeof(*desc));
 252         desc->bDescriptorType = 0x29;
 253         desc->bDescLength = 9;
 254         desc->wHubCharacteristics = (__force __u16)
 255                 (__constant_cpu_to_le16(0x0001));
 256         desc->bNbrPorts = VHCI_NPORTS;
 257         desc->u.hs.DeviceRemovable[0] = 0xff;
 258         desc->u.hs.DeviceRemovable[1] = 0xff;
 259 }
 260
 261 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 262                             u16 wIndex, char *buf, u16 wLength)
 263 {
 264         struct vhci_hcd *dum;
 265         int             retval = 0;
 266         unsigned long   flags;
 267         int             rhport;
 268
 269         u32 prev_port_status[VHCI_NPORTS];
 270
 271         if (!HCD_HW_ACCESSIBLE(hcd))
 272                 return -ETIMEDOUT;
 273
 274         /*
 275          * NOTE:
 276          * wIndex shows the port number and begins from 1.
 277          */
 278         usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 279                           wIndex);
 280         if (wIndex > VHCI_NPORTS)
 281                 pr_err("invalid port number %d\n", wIndex);
 282         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 283
 284         dum = hcd_to_vhci(hcd);
 285
 286         spin_lock_irqsave(&dum->lock, flags);
 287
 288         /* store old status and compare now and old later */
 289         if (usbip_dbg_flag_vhci_rh) {
 290                 memcpy(prev_port_status, dum->port_status,
 291                         sizeof(prev_port_status));
 292         }
 293
 294         switch (typeReq) {
 295         case ClearHubFeature:
 296                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
 297                 break;
 298         case ClearPortFeature:
 299                 switch (wValue) {
 300                 case USB_PORT_FEAT_SUSPEND:
 301                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
 302                                 /* 20msec signaling */
 303                                 dum->resuming = 1;
 304                                 dum->re_timeout =
 305                                         jiffies + msecs_to_jiffies(20);
 306                         }
 307                         break;
 308                 case USB_PORT_FEAT_POWER:
 309                         usbip_dbg_vhci_rh(" ClearPortFeature: "
 310                                           "USB_PORT_FEAT_POWER\n");
 311                         dum->port_status[rhport] = 0;
 312                         /* dum->address = 0; */
 313                         /* dum->hdev = 0; */
 314                         dum->resuming = 0;
 315                         break;
 316                 case USB_PORT_FEAT_C_RESET:
 317                         usbip_dbg_vhci_rh(" ClearPortFeature: "
 318                                           "USB_PORT_FEAT_C_RESET\n");
 319                         switch (dum->vdev[rhport].speed) {
 320                         case USB_SPEED_HIGH:
 321                                 dum->port_status[rhport] |=
 322                                         USB_PORT_STAT_HIGH_SPEED;
 323                                 break;
 324                         case USB_SPEED_LOW:
 325                                 dum->port_status[rhport] |=
 326                                         USB_PORT_STAT_LOW_SPEED;
 327                                 break;
 328                         default:
 329                                 break;
 330                         }
 331                 default:
 332                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 333                                           wValue);
 334                         dum->port_status[rhport] &= ~(1 << wValue);
 335                         break;
 336                 }
 337                 break;
 338         case GetHubDescriptor:
 339                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 340                 hub_descriptor((struct usb_hub_descriptor *) buf);
 341                 break;
 342         case GetHubStatus:
 343                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 344                 *(__le32 *) buf = __constant_cpu_to_le32(0);
 345                 break;
 346         case GetPortStatus:
 347                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 348                 if (wIndex > VHCI_NPORTS || wIndex < 1) {
 349                         pr_err("invalid port number %d\n", wIndex);
 350                         retval = -EPIPE;
 351                 }
 352
 353                 /* we do no care of resume. */
 354
 355                 /* whoever resets or resumes must GetPortStatus to
 356                  * complete it!!
 357                  *                                   */
 358                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 359                         dum->port_status[rhport] |=
 360                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 361                         dum->port_status[rhport] &=
 362                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 363                         dum->resuming = 0;
 364                         dum->re_timeout = 0;
 365                         /* if (dum->driver && dum->driver->resume) {
 366                          *      spin_unlock (&dum->lock);
 367                          *      dum->driver->resume (&dum->gadget);
 368                          *      spin_lock (&dum->lock);
 369                          * } */
 370                 }
 371
 372                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 373                     0 && time_after(jiffies, dum->re_timeout)) {
 374                         dum->port_status[rhport] |=
 375                                 (1 << USB_PORT_FEAT_C_RESET);
 376                         dum->port_status[rhport] &=
 377                                 ~(1 << USB_PORT_FEAT_RESET);
 378                         dum->re_timeout = 0;
 379
 380                         if (dum->vdev[rhport].ud.status ==
 381                             VDEV_ST_NOTASSIGNED) {
 382                                 usbip_dbg_vhci_rh(" enable rhport %d "
 383                                                   "(status %u)\n",
 384                                                   rhport,
 385                                                   dum->vdev[rhport].ud.status);
 386                                 dum->port_status[rhport] |=
 387                                         USB_PORT_STAT_ENABLE;
 388                         }
 389                 }
 390                 ((u16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 391                 ((u16 *) buf)[1] = cpu_to_le16(dum->port_status[rhport] >> 16);
 392
 393                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 394                                   ((u16 *)buf)[1]);
 395                 break;
 396         case SetHubFeature:
 397                 usbip_dbg_vhci_rh(" SetHubFeature\n");
 398                 retval = -EPIPE;
 399                 break;
 400         case SetPortFeature:
 401                 switch (wValue) {
 402                 case USB_PORT_FEAT_SUSPEND:
 403                         usbip_dbg_vhci_rh(" SetPortFeature: "
 404                                           "USB_PORT_FEAT_SUSPEND\n");
 405                         break;
 406                 case USB_PORT_FEAT_RESET:
 407                         usbip_dbg_vhci_rh(" SetPortFeature: "
 408                                           "USB_PORT_FEAT_RESET\n");
 409                         /* if it's already running, disconnect first */
 410                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 411                                 dum->port_status[rhport] &=
 412                                         ~(USB_PORT_STAT_ENABLE |
 413                                           USB_PORT_STAT_LOW_SPEED |
 414                                           USB_PORT_STAT_HIGH_SPEED);
 415                                 /* FIXME test that code path! */
 416                         }
 417                         /* 50msec reset signaling */
 418                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
 419
 420                         /* FALLTHROUGH */
 421                 default:
 422                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 423                                           wValue);
 424                         dum->port_status[rhport] |= (1 << wValue);
 425                         break;
 426                 }
 427                 break;
 428
 429         default:
 430                 pr_err("default: no such request\n");
 431                 /* dev_dbg (hardware,
 432                  *              "hub control req%04x v%04x i%04x l%d\n",
 433                  *              typeReq, wValue, wIndex, wLength); */
 434
 435                 /* "protocol stall" on error */
 436                 retval = -EPIPE;
 437         }
 438
 439         if (usbip_dbg_flag_vhci_rh) {
 440                 pr_debug("port %d\n", rhport);
 441                 /* Only dump valid port status */
 442                 if (rhport >= 0) {
 443                         dump_port_status_diff(prev_port_status[rhport],
 444                                               dum->port_status[rhport]);
 445                 }
 446         }
 447         usbip_dbg_vhci_rh(" bye\n");
 448
 449         spin_unlock_irqrestore(&dum->lock, flags);
 450
 451         return retval;
 452 }
 453
 454 static struct vhci_device *get_vdev(struct usb_device *udev)
 455 {
 456         int i;
 457
 458         if (!udev)
 459                 return NULL;
 460
 461         for (i = 0; i < VHCI_NPORTS; i++)
 462                 if (the_controller->vdev[i].udev == udev)
 463                         return port_to_vdev(i);
 464
 465         return NULL;
 466 }
 467
 468 static void vhci_tx_urb(struct urb *urb)
 469 {
 470         struct vhci_device *vdev = get_vdev(urb->dev);
 471         struct vhci_priv *priv;
 472         unsigned long flag;
 473
 474         if (!vdev) {
 475                 pr_err("could not get virtual device");
 476                 /* BUG(); */
 477                 return;
 478         }
 479
 480         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 481
 482         spin_lock_irqsave(&vdev->priv_lock, flag);
 483
 484         if (!priv) {
 485                 dev_err(&urb->dev->dev, "malloc vhci_priv\n");
 486                 spin_unlock_irqrestore(&vdev->priv_lock, flag);
 487                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 488                 return;
 489         }
 490
 491         priv->seqnum = atomic_inc_return(&the_controller->seqnum);
 492         if (priv->seqnum == 0xffff)
 493                 dev_info(&urb->dev->dev, "seqnum max\n");
 494
 495         priv->vdev = vdev;
 496         priv->urb = urb;
 497
 498         urb->hcpriv = (void *) priv;
 499
 500         list_add_tail(&priv->list, &vdev->priv_tx);
 501
 502         wake_up(&vdev->waitq_tx);
 503         spin_unlock_irqrestore(&vdev->priv_lock, flag);
 504 }
 505
 506 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 507                             gfp_t mem_flags)
 508 {
 509         struct device *dev = &urb->dev->dev;
 510         int ret = 0;
 511         unsigned long flags;
 512         struct vhci_device *vdev;
 513
 514         usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
 515                           hcd, urb, mem_flags);
 516
 517         /* patch to usb_sg_init() is in 2.5.60 */
 518         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 519
 520         spin_lock_irqsave(&the_controller->lock, flags);
 521
 522         if (urb->status != -EINPROGRESS) {
 523                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 524                 spin_unlock_irqrestore(&the_controller->lock, flags);
 525                 return urb->status;
 526         }
 527
 528         vdev = port_to_vdev(urb->dev->portnum-1);
 529
 530         /* refuse enqueue for dead connection */
 531         spin_lock(&vdev->ud.lock);
 532         if (vdev->ud.status == VDEV_ST_NULL ||
 533             vdev->ud.status == VDEV_ST_ERROR) {
 534                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 535                 spin_unlock(&vdev->ud.lock);
 536                 spin_unlock_irqrestore(&the_controller->lock, flags);
 537                 return -ENODEV;
 538         }
 539         spin_unlock(&vdev->ud.lock);
 540
 541         ret = usb_hcd_link_urb_to_ep(hcd, urb);
 542         if (ret)
 543                 goto no_need_unlink;
 544
 545         /*
 546          * The enumeration process is as follows;
 547          *
 548          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 549          *     to get max packet length of default pipe
 550          *
 551          *  2. Set_Address request to DevAddr(0) EndPoint(0)
 552          *
 553          */
 554         if (usb_pipedevice(urb->pipe) == 0) {
 555                 __u8 type = usb_pipetype(urb->pipe);
 556                 struct usb_ctrlrequest *ctrlreq =
 557                         (struct usb_ctrlrequest *) urb->setup_packet;
 558
 559                 if (type != PIPE_CONTROL || !ctrlreq) {
 560                         dev_err(dev, "invalid request to devnum 0\n");
 561                         ret = -EINVAL;
 562                         goto no_need_xmit;
 563                 }
 564
 565                 switch (ctrlreq->bRequest) {
 566                 case USB_REQ_SET_ADDRESS:
 567                         /* set_address may come when a device is reset */
 568                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
 569                                  ctrlreq->wValue, vdev->rhport);
 570
 571                         if (vdev->udev)
 572                                 usb_put_dev(vdev->udev);
 573                         vdev->udev = usb_get_dev(urb->dev);
 574
 575                         spin_lock(&vdev->ud.lock);
 576                         vdev->ud.status = VDEV_ST_USED;
 577                         spin_unlock(&vdev->ud.lock);
 578
 579                         if (urb->status == -EINPROGRESS) {
 580                                 /* This request is successfully completed. */
 581                                 /* If not -EINPROGRESS, possibly unlinked. */
 582                                 urb->status = 0;
 583                         }
 584
 585                         goto no_need_xmit;
 586
 587                 case USB_REQ_GET_DESCRIPTOR:
 588                         if (ctrlreq->wValue == (USB_DT_DEVICE << 8))
 589                                 usbip_dbg_vhci_hc("Not yet?: "
 590                                                   "Get_Descriptor to device 0 "
 591                                                   "(get max pipe size)\n");
 592
 593                         if (vdev->udev)
 594                                 usb_put_dev(vdev->udev);
 595                         vdev->udev = usb_get_dev(urb->dev);
 596                         goto out;
 597
 598                 default:
 599                         /* NOT REACHED */
 600                         dev_err(dev, "invalid request to devnum 0 bRequest %u, "
 601                                 "wValue %u\n", ctrlreq->bRequest,
 602                                 ctrlreq->wValue);
 603                         ret =  -EINVAL;
 604                         goto no_need_xmit;
 605                 }
 606
 607         }
 608
 609 out:
 610         vhci_tx_urb(urb);
 611         spin_unlock_irqrestore(&the_controller->lock, flags);
 612
 613         return 0;
 614
 615 no_need_xmit:
 616         usb_hcd_unlink_urb_from_ep(hcd, urb);
 617 no_need_unlink:
 618         spin_unlock_irqrestore(&the_controller->lock, flags);
 619         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 620         return ret;
 621 }
 622
 623 /*
 624  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 625  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 626  * back its urb. For the driver unlinking the urb, the content of the urb is
 627  * not important, but the calling to its completion handler is important; the
 628  * completion of unlinking is notified by the completion handler.
 629  *
 630  *
 631  * CLIENT SIDE
 632  *
 633  * - When vhci_hcd receives RET_SUBMIT,
 634  *
 635  *      - case 1a). the urb of the pdu is not unlinking.
 636  *              - normal case
 637  *              => just give back the urb
 638  *
 639  *      - case 1b). the urb of the pdu is unlinking.
 640  *              - usbip.ko will return a reply of the unlinking request.
 641  *              => give back the urb now and go to case 2b).
 642  *
 643  * - When vhci_hcd receives RET_UNLINK,
 644  *
 645  *      - case 2a). a submit request is still pending in vhci_hcd.
 646  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 647  *                completed there.
 648  *              => free a pending submit request
 649  *              => notify unlink completeness by giving back the urb
 650  *
 651  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 652  *              - urb was already given back to the core driver.
 653  *              => do not give back the urb
 654  *
 655  *
 656  * SERVER SIDE
 657  *
 658  * - When usbip receives CMD_UNLINK,
 659  *
 660  *      - case 3a). the urb of the unlink request is now in submission.
 661  *              => do usb_unlink_urb().
 662  *              => after the unlink is completed, send RET_UNLINK.
 663  *
 664  *      - case 3b). the urb of the unlink request is not in submission.
 665  *              - may be already completed or never be received
 666  *              => send RET_UNLINK
 667  *
 668  */
 669 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 670 {
 671         unsigned long flags;
 672         struct vhci_priv *priv;
 673         struct vhci_device *vdev;
 674
 675         pr_info("dequeue a urb %p\n", urb);
 676
 677         spin_lock_irqsave(&the_controller->lock, flags);
 678
 679         priv = urb->hcpriv;
 680         if (!priv) {
 681                 /* URB was never linked! or will be soon given back by
 682                  * vhci_rx. */
 683                 spin_unlock_irqrestore(&the_controller->lock, flags);
 684                 return 0;
 685         }
 686
 687         {
 688                 int ret = 0;
 689                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 690                 if (ret) {
 691                         spin_unlock_irqrestore(&the_controller->lock, flags);
 692                         return ret;
 693                 }
 694         }
 695
 696          /* send unlink request here? */
 697         vdev = priv->vdev;
 698
 699         if (!vdev->ud.tcp_socket) {
 700                 /* tcp connection is closed */
 701                 unsigned long flags2;
 702
 703                 spin_lock_irqsave(&vdev->priv_lock, flags2);
 704
 705                 pr_info("device %p seems to be disconnected\n", vdev);
 706                 list_del(&priv->list);
 707                 kfree(priv);
 708                 urb->hcpriv = NULL;
 709
 710                 spin_unlock_irqrestore(&vdev->priv_lock, flags2);
 711
 712                 /*
 713                  * If tcp connection is alive, we have sent CMD_UNLINK.
 714                  * vhci_rx will receive RET_UNLINK and give back the URB.
 715                  * Otherwise, we give back it here.
 716                  */
 717                 pr_info("gives back urb %p\n", urb);
 718
 719                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 720
 721                 spin_unlock_irqrestore(&the_controller->lock, flags);
 722                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 723                                      urb->status);
 724                 spin_lock_irqsave(&the_controller->lock, flags);
 725
 726         } else {
 727                 /* tcp connection is alive */
 728                 unsigned long flags2;
 729                 struct vhci_unlink *unlink;
 730
 731                 spin_lock_irqsave(&vdev->priv_lock, flags2);
 732
 733                 /* setup CMD_UNLINK pdu */
 734                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 735                 if (!unlink) {
 736                         pr_err("malloc vhci_unlink\n");
 737                         spin_unlock_irqrestore(&vdev->priv_lock, flags2);
 738                         spin_unlock_irqrestore(&the_controller->lock, flags);
 739                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 740                         return -ENOMEM;
 741                 }
 742
 743                 unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
 744                 if (unlink->seqnum == 0xffff)
 745                         pr_info("seqnum max\n");
 746
 747                 unlink->unlink_seqnum = priv->seqnum;
 748
 749                 pr_info("device %p seems to be still connected\n", vdev);
 750
 751                 /* send cmd_unlink and try to cancel the pending URB in the
 752                  * peer */
 753                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 754                 wake_up(&vdev->waitq_tx);
 755
 756                 spin_unlock_irqrestore(&vdev->priv_lock, flags2);
 757         }
 758
 759         spin_unlock_irqrestore(&the_controller->lock, flags);
 760
 761         usbip_dbg_vhci_hc("leave\n");
 762         return 0;
 763 }
 764
 765 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 766 {
 767         struct vhci_unlink *unlink, *tmp;
 768
 769         spin_lock(&vdev->priv_lock);
 770
 771         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 772                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 773                 list_del(&unlink->list);
 774                 kfree(unlink);
 775         }
 776
 777         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 778                 struct urb *urb;
 779
 780                 /* give back URB of unanswered unlink request */
 781                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 782
 783                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 784                 if (!urb) {
 785                         pr_info("the urb (seqnum %lu) was already given back\n",
 786                                 unlink->unlink_seqnum);
 787                         list_del(&unlink->list);
 788                         kfree(unlink);
 789                         continue;
 790                 }
 791
 792                 urb->status = -ENODEV;
 793
 794                 spin_lock(&the_controller->lock);
 795                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 796                 spin_unlock(&the_controller->lock);
 797
 798                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 799                                      urb->status);
 800
 801                 list_del(&unlink->list);
 802                 kfree(unlink);
 803         }
 804
 805         spin_unlock(&vdev->priv_lock);
 806 }
 807
 808 /*
 809  * The important thing is that only one context begins cleanup.
 810  * This is why error handling and cleanup become simple.
 811  * We do not want to consider race condition as possible.
 812  */
 813 static void vhci_shutdown_connection(struct usbip_device *ud)
 814 {
 815         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 816
 817         /* need this? see stub_dev.c */
 818         if (ud->tcp_socket) {
 819                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 820                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 821         }
 822
 823         /* kill threads related to this sdev, if v.c. exists */
 824         if (vdev->ud.tcp_rx && !task_is_dead(vdev->ud.tcp_rx))
 825                 kthread_stop(vdev->ud.tcp_rx);
 826         if (vdev->ud.tcp_tx && !task_is_dead(vdev->ud.tcp_tx))
 827                 kthread_stop(vdev->ud.tcp_tx);
 828
 829         pr_info("stop threads\n");
 830
 831         /* active connection is closed */
 832         if (vdev->ud.tcp_socket != NULL) {
 833                 sock_release(vdev->ud.tcp_socket);
 834                 vdev->ud.tcp_socket = NULL;
 835         }
 836         pr_info("release socket\n");
 837
 838         vhci_device_unlink_cleanup(vdev);
 839
 840         /*
 841          * rh_port_disconnect() is a trigger of ...
 842          *   usb_disable_device():
 843          *      disable all the endpoints for a USB device.
 844          *   usb_disable_endpoint():
 845          *      disable endpoints. pending urbs are unlinked(dequeued).
 846          *
 847          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 848          * deteched device should release used urbs in a cleanup function(i.e.
 849          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 850          * pushed urbs and their private data in this function.
 851          *
 852          * NOTE: vhci_dequeue() must be considered carefully. When shutdowning
 853          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 854          * gives back pushed urbs and frees their private data by request of
 855          * the cleanup function of a USB driver. When unlinking a urb with an
 856          * active connection, vhci_dequeue() does not give back the urb which
 857          * is actually given back by vhci_rx after receiving its return pdu.
 858          *
 859          */
 860         rh_port_disconnect(vdev->rhport);
 861
 862         pr_info("disconnect device\n");
 863 }
 864
 865
 866 static void vhci_device_reset(struct usbip_device *ud)
 867 {
 868         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 869
 870         spin_lock(&ud->lock);
 871
 872         vdev->speed  = 0;
 873         vdev->devid  = 0;
 874
 875         if (vdev->udev)
 876                 usb_put_dev(vdev->udev);
 877         vdev->udev = NULL;
 878
 879         ud->tcp_socket = NULL;
 880         ud->status = VDEV_ST_NULL;
 881
 882         spin_unlock(&ud->lock);
 883 }
 884
 885 static void vhci_device_unusable(struct usbip_device *ud)
 886 {
 887         spin_lock(&ud->lock);
 888         ud->status = VDEV_ST_ERROR;
 889         spin_unlock(&ud->lock);
 890 }
 891
 892 static void vhci_device_init(struct vhci_device *vdev)
 893 {
 894         memset(vdev, 0, sizeof(*vdev));
 895
 896         vdev->ud.side   = USBIP_VHCI;
 897         vdev->ud.status = VDEV_ST_NULL;
 898         spin_lock_init(&vdev->ud.lock);
 899
 900         INIT_LIST_HEAD(&vdev->priv_rx);
 901         INIT_LIST_HEAD(&vdev->priv_tx);
 902         INIT_LIST_HEAD(&vdev->unlink_tx);
 903         INIT_LIST_HEAD(&vdev->unlink_rx);
 904         spin_lock_init(&vdev->priv_lock);
 905
 906         init_waitqueue_head(&vdev->waitq_tx);
 907
 908         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 909         vdev->ud.eh_ops.reset = vhci_device_reset;
 910         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 911
 912         usbip_start_eh(&vdev->ud);
 913 }
 914
 915 static int vhci_start(struct usb_hcd *hcd)
 916 {
 917         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 918         int rhport;
 919         int err = 0;
 920
 921         usbip_dbg_vhci_hc("enter vhci_start\n");
 922
 923         /* initialize private data of usb_hcd */
 924
 925         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 926                 struct vhci_device *vdev = &vhci->vdev[rhport];
 927                 vhci_device_init(vdev);
 928                 vdev->rhport = rhport;
 929         }
 930
 931         atomic_set(&vhci->seqnum, 0);
 932         spin_lock_init(&vhci->lock);
 933
 934         hcd->power_budget = 0; /* no limit */
 935         hcd->state  = HC_STATE_RUNNING;
 936         hcd->uses_new_polling = 1;
 937
 938         /* vhci_hcd is now ready to be controlled through sysfs */
 939         err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 940         if (err) {
 941                 pr_err("create sysfs files\n");
 942                 return err;
 943         }
 944
 945         return 0;
 946 }
 947
 948 static void vhci_stop(struct usb_hcd *hcd)
 949 {
 950         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 951         int rhport = 0;
 952
 953         usbip_dbg_vhci_hc("stop VHCI controller\n");
 954
 955         /* 1. remove the userland interface of vhci_hcd */
 956         sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 957
 958         /* 2. shutdown all the ports of vhci_hcd */
 959         for (rhport = 0 ; rhport < VHCI_NPORTS; rhport++) {
 960                 struct vhci_device *vdev = &vhci->vdev[rhport];
 961
 962                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
 963                 usbip_stop_eh(&vdev->ud);
 964         }
 965 }
 966
 967 static int vhci_get_frame_number(struct usb_hcd *hcd)
 968 {
 969         pr_err("Not yet implemented\n");
 970         return 0;
 971 }
 972
 973 #ifdef CONFIG_PM
 974
 975 /* FIXME: suspend/resume */
 976 static int vhci_bus_suspend(struct usb_hcd *hcd)
 977 {
 978         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 979
 980         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 981
 982         spin_lock_irq(&vhci->lock);
 983         /* vhci->rh_state = DUMMY_RH_SUSPENDED;
 984          * set_link_state(vhci); */
 985         hcd->state = HC_STATE_SUSPENDED;
 986         spin_unlock_irq(&vhci->lock);
 987
 988         return 0;
 989 }
 990
 991 static int vhci_bus_resume(struct usb_hcd *hcd)
 992 {
 993         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 994         int rc = 0;
 995
 996         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 997
 998         spin_lock_irq(&vhci->lock);
 999         if (!HCD_HW_ACCESSIBLE(hcd)) {
1000                 rc = -ESHUTDOWN;
1001         } else {
1002                 /* vhci->rh_state = DUMMY_RH_RUNNING;
1003                  * set_link_state(vhci);
1004                  * if (!list_empty(&vhci->urbp_list))
1005                  *      mod_timer(&vhci->timer, jiffies); */
1006                 hcd->state = HC_STATE_RUNNING;
1007         }
1008         spin_unlock_irq(&vhci->lock);
1009
1010         return rc;
1011 }
1012
1013 #else
1014
1015 #define vhci_bus_suspend      NULL
1016 #define vhci_bus_resume       NULL
1017 #endif
1018
1019 static struct hc_driver vhci_hc_driver = {
1020         .description    = driver_name,
1021         .product_desc   = driver_desc,
1022         .hcd_priv_size  = sizeof(struct vhci_hcd),
1023
1024         .flags          = HCD_USB2,
1025
1026         .start          = vhci_start,
1027         .stop           = vhci_stop,
1028
1029         .urb_enqueue    = vhci_urb_enqueue,
1030         .urb_dequeue    = vhci_urb_dequeue,
1031
1032         .get_frame_number = vhci_get_frame_number,
1033
1034         .hub_status_data = vhci_hub_status,
1035         .hub_control    = vhci_hub_control,
1036         .bus_suspend    = vhci_bus_suspend,
1037         .bus_resume     = vhci_bus_resume,
1038 };
1039
1040 static int vhci_hcd_probe(struct platform_device *pdev)
1041 {
1042         struct usb_hcd          *hcd;
1043         int                     ret;
1044
1045         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1046
1047         /* will be removed */
1048         if (pdev->dev.dma_mask) {
1049                 dev_info(&pdev->dev, "vhci_hcd DMA not supported\n");
1050                 return -EINVAL;
1051         }
1052
1053         /*
1054          * Allocate and initialize hcd.
1055          * Our private data is also allocated automatically.
1056          */
1057         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1058         if (!hcd) {
1059                 pr_err("create hcd failed\n");
1060                 return -ENOMEM;
1061         }
1062         hcd->has_tt = 1;
1063
1064         /* this is private data for vhci_hcd */
1065         the_controller = hcd_to_vhci(hcd);
1066
1067         /*
1068          * Finish generic HCD structure initialization and register.
1069          * Call the driver's reset() and start() routines.
1070          */
1071         ret = usb_add_hcd(hcd, 0, 0);
1072         if (ret != 0) {
1073                 pr_err("usb_add_hcd failed %d\n", ret);
1074                 usb_put_hcd(hcd);
1075                 the_controller = NULL;
1076                 return ret;
1077         }
1078
1079         usbip_dbg_vhci_hc("bye\n");
1080         return 0;
1081 }
1082
1083 static int vhci_hcd_remove(struct platform_device *pdev)
1084 {
1085         struct usb_hcd  *hcd;
1086
1087         hcd = platform_get_drvdata(pdev);
1088         if (!hcd)
1089                 return 0;
1090
1091         /*
1092          * Disconnects the root hub,
1093          * then reverses the effects of usb_add_hcd(),
1094          * invoking the HCD's stop() methods.
1095          */
1096         usb_remove_hcd(hcd);
1097         usb_put_hcd(hcd);
1098         the_controller = NULL;
1099
1100         return 0;
1101 }
1102
1103 #ifdef CONFIG_PM
1104
1105 /* what should happen for USB/IP under suspend/resume? */
1106 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1107 {
1108         struct usb_hcd *hcd;
1109         int rhport = 0;
1110         int connected = 0;
1111         int ret = 0;
1112
1113         hcd = platform_get_drvdata(pdev);
1114
1115         spin_lock(&the_controller->lock);
1116
1117         for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1118                 if (the_controller->port_status[rhport] &
1119                     USB_PORT_STAT_CONNECTION)
1120                         connected += 1;
1121
1122         spin_unlock(&the_controller->lock);
1123
1124         if (connected > 0) {
1125                 dev_info(&pdev->dev, "We have %d active connection%s. Do not "
1126                          "suspend.\n", connected, (connected == 1 ? "" : "s"));
1127                 ret =  -EBUSY;
1128         } else {
1129                 dev_info(&pdev->dev, "suspend vhci_hcd");
1130                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1131         }
1132
1133         return ret;
1134 }
1135
1136 static int vhci_hcd_resume(struct platform_device *pdev)
1137 {
1138         struct usb_hcd *hcd;
1139
1140         dev_dbg(&pdev->dev, "%s\n", __func__);
1141
1142         hcd = platform_get_drvdata(pdev);
1143         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1144         usb_hcd_poll_rh_status(hcd);
1145
1146         return 0;
1147 }
1148
1149 #else
1150
1151 #define vhci_hcd_suspend        NULL
1152 #define vhci_hcd_resume         NULL
1153
1154 #endif
1155
1156 static struct platform_driver vhci_driver = {
1157         .probe  = vhci_hcd_probe,
1158         .remove = __devexit_p(vhci_hcd_remove),
1159         .suspend = vhci_hcd_suspend,
1160         .resume = vhci_hcd_resume,
1161         .driver = {
1162                 .name = (char *) driver_name,
1163                 .owner = THIS_MODULE,
1164         },
1165 };
1166
1167 /*
1168  * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1169  * We need to add this virtual device as a platform device arbitrarily:
1170  *      1. platform_device_register()
1171  */
1172 static void the_pdev_release(struct device *dev)
1173 {
1174         return;
1175 }
1176
1177 static struct platform_device the_pdev = {
1178         /* should be the same name as driver_name */
1179         .name = (char *) driver_name,
1180         .id = -1,
1181         .dev = {
1182                 /* .driver = &vhci_driver, */
1183                 .release = the_pdev_release,
1184         },
1185 };
1186
1187 static int __init vhci_hcd_init(void)
1188 {
1189         int ret;
1190
1191         if (usb_disabled())
1192                 return -ENODEV;
1193
1194         ret = platform_driver_register(&vhci_driver);
1195         if (ret < 0)
1196                 goto err_driver_register;
1197
1198         ret = platform_device_register(&the_pdev);
1199         if (ret < 0)
1200                 goto err_platform_device_register;
1201
1202         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1203         return ret;
1204
1205 err_platform_device_register:
1206         platform_driver_unregister(&vhci_driver);
1207 err_driver_register:
1208         return ret;
1209 }
1210
1211 static void __exit vhci_hcd_exit(void)
1212 {
1213         platform_device_unregister(&the_pdev);
1214         platform_driver_unregister(&vhci_driver);
1215 }
1216
1217 module_init(vhci_hcd_init);
1218 module_exit(vhci_hcd_exit);
1219
1220 MODULE_AUTHOR(DRIVER_AUTHOR);
1221 MODULE_DESCRIPTION(DRIVER_DESC);
1222 MODULE_LICENSE("GPL");
1223 MODULE_VERSION(USBIP_VERSION);