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         int width;
 252
 253         memset(desc, 0, sizeof(*desc));
 254         desc->bDescriptorType = 0x29;
 255         desc->wHubCharacteristics = (__force __u16)
 256                 (__constant_cpu_to_le16(0x0001));
 257
 258         desc->bNbrPorts = VHCI_NPORTS;
 259         BUILD_BUG_ON(VHCI_NPORTS > USB_MAXCHILDREN);
 260         width = desc->bNbrPorts / 8 + 1;
 261         desc->bDescLength = USB_DT_HUB_NONVAR_SIZE + 2 * width;
 262         memset(&desc->u.hs.DeviceRemovable[0], 0, width);
 263         memset(&desc->u.hs.DeviceRemovable[width], 0xff, width);
 264 }
 265
 266 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 267                             u16 wIndex, char *buf, u16 wLength)
 268 {
 269         struct vhci_hcd *dum;
 270         int             retval = 0;
 271         unsigned long   flags;
 272         int             rhport;
 273
 274         u32 prev_port_status[VHCI_NPORTS];
 275
 276         if (!HCD_HW_ACCESSIBLE(hcd))
 277                 return -ETIMEDOUT;
 278
 279         /*
 280          * NOTE:
 281          * wIndex shows the port number and begins from 1.
 282          */
 283         usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 284                           wIndex);
 285         if (wIndex > VHCI_NPORTS)
 286                 pr_err("invalid port number %d\n", wIndex);
 287         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 288
 289         dum = hcd_to_vhci(hcd);
 290
 291         spin_lock_irqsave(&dum->lock, flags);
 292
 293         /* store old status and compare now and old later */
 294         if (usbip_dbg_flag_vhci_rh) {
 295                 memcpy(prev_port_status, dum->port_status,
 296                         sizeof(prev_port_status));
 297         }
 298
 299         switch (typeReq) {
 300         case ClearHubFeature:
 301                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
 302                 break;
 303         case ClearPortFeature:
 304                 switch (wValue) {
 305                 case USB_PORT_FEAT_SUSPEND:
 306                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
 307                                 /* 20msec signaling */
 308                                 dum->resuming = 1;
 309                                 dum->re_timeout =
 310                                         jiffies + msecs_to_jiffies(20);
 311                         }
 312                         break;
 313                 case USB_PORT_FEAT_POWER:
 314                         usbip_dbg_vhci_rh(" ClearPortFeature: "
 315                                           "USB_PORT_FEAT_POWER\n");
 316                         dum->port_status[rhport] = 0;
 317                         /* dum->address = 0; */
 318                         /* dum->hdev = 0; */
 319                         dum->resuming = 0;
 320                         break;
 321                 case USB_PORT_FEAT_C_RESET:
 322                         usbip_dbg_vhci_rh(" ClearPortFeature: "
 323                                           "USB_PORT_FEAT_C_RESET\n");
 324                         switch (dum->vdev[rhport].speed) {
 325                         case USB_SPEED_HIGH:
 326                                 dum->port_status[rhport] |=
 327                                         USB_PORT_STAT_HIGH_SPEED;
 328                                 break;
 329                         case USB_SPEED_LOW:
 330                                 dum->port_status[rhport] |=
 331                                         USB_PORT_STAT_LOW_SPEED;
 332                                 break;
 333                         default:
 334                                 break;
 335                         }
 336                 default:
 337                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 338                                           wValue);
 339                         dum->port_status[rhport] &= ~(1 << wValue);
 340                         break;
 341                 }
 342                 break;
 343         case GetHubDescriptor:
 344                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 345                 hub_descriptor((struct usb_hub_descriptor *) buf);
 346                 break;
 347         case GetHubStatus:
 348                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 349                 *(__le32 *) buf = __constant_cpu_to_le32(0);
 350                 break;
 351         case GetPortStatus:
 352                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 353                 if (wIndex > VHCI_NPORTS || wIndex < 1) {
 354                         pr_err("invalid port number %d\n", wIndex);
 355                         retval = -EPIPE;
 356                 }
 357
 358                 /* we do no care of resume. */
 359
 360                 /* whoever resets or resumes must GetPortStatus to
 361                  * complete it!!
 362                  *                                   */
 363                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 364                         dum->port_status[rhport] |=
 365                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 366                         dum->port_status[rhport] &=
 367                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 368                         dum->resuming = 0;
 369                         dum->re_timeout = 0;
 370                         /* if (dum->driver && dum->driver->resume) {
 371                          *      spin_unlock (&dum->lock);
 372                          *      dum->driver->resume (&dum->gadget);
 373                          *      spin_lock (&dum->lock);
 374                          * } */
 375                 }
 376
 377                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 378                     0 && time_after(jiffies, dum->re_timeout)) {
 379                         dum->port_status[rhport] |=
 380                                 (1 << USB_PORT_FEAT_C_RESET);
 381                         dum->port_status[rhport] &=
 382                                 ~(1 << USB_PORT_FEAT_RESET);
 383                         dum->re_timeout = 0;
 384
 385                         if (dum->vdev[rhport].ud.status ==
 386                             VDEV_ST_NOTASSIGNED) {
 387                                 usbip_dbg_vhci_rh(" enable rhport %d "
 388                                                   "(status %u)\n",
 389                                                   rhport,
 390                                                   dum->vdev[rhport].ud.status);
 391                                 dum->port_status[rhport] |=
 392                                         USB_PORT_STAT_ENABLE;
 393                         }
 394                 }
 395                 ((u16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 396                 ((u16 *) buf)[1] = cpu_to_le16(dum->port_status[rhport] >> 16);
 397
 398                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 399                                   ((u16 *)buf)[1]);
 400                 break;
 401         case SetHubFeature:
 402                 usbip_dbg_vhci_rh(" SetHubFeature\n");
 403                 retval = -EPIPE;
 404                 break;
 405         case SetPortFeature:
 406                 switch (wValue) {
 407                 case USB_PORT_FEAT_SUSPEND:
 408                         usbip_dbg_vhci_rh(" SetPortFeature: "
 409                                           "USB_PORT_FEAT_SUSPEND\n");
 410                         break;
 411                 case USB_PORT_FEAT_RESET:
 412                         usbip_dbg_vhci_rh(" SetPortFeature: "
 413                                           "USB_PORT_FEAT_RESET\n");
 414                         /* if it's already running, disconnect first */
 415                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 416                                 dum->port_status[rhport] &=
 417                                         ~(USB_PORT_STAT_ENABLE |
 418                                           USB_PORT_STAT_LOW_SPEED |
 419                                           USB_PORT_STAT_HIGH_SPEED);
 420                                 /* FIXME test that code path! */
 421                         }
 422                         /* 50msec reset signaling */
 423                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
 424
 425                         /* FALLTHROUGH */
 426                 default:
 427                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 428                                           wValue);
 429                         dum->port_status[rhport] |= (1 << wValue);
 430                         break;
 431                 }
 432                 break;
 433
 434         default:
 435                 pr_err("default: no such request\n");
 436                 /* dev_dbg (hardware,
 437                  *              "hub control req%04x v%04x i%04x l%d\n",
 438                  *              typeReq, wValue, wIndex, wLength); */
 439
 440                 /* "protocol stall" on error */
 441                 retval = -EPIPE;
 442         }
 443
 444         if (usbip_dbg_flag_vhci_rh) {
 445                 pr_debug("port %d\n", rhport);
 446                 /* Only dump valid port status */
 447                 if (rhport >= 0) {
 448                         dump_port_status_diff(prev_port_status[rhport],
 449                                               dum->port_status[rhport]);
 450                 }
 451         }
 452         usbip_dbg_vhci_rh(" bye\n");
 453
 454         spin_unlock_irqrestore(&dum->lock, flags);
 455
 456         return retval;
 457 }
 458
 459 static struct vhci_device *get_vdev(struct usb_device *udev)
 460 {
 461         int i;
 462
 463         if (!udev)
 464                 return NULL;
 465
 466         for (i = 0; i < VHCI_NPORTS; i++)
 467                 if (the_controller->vdev[i].udev == udev)
 468                         return port_to_vdev(i);
 469
 470         return NULL;
 471 }
 472
 473 static void vhci_tx_urb(struct urb *urb)
 474 {
 475         struct vhci_device *vdev = get_vdev(urb->dev);
 476         struct vhci_priv *priv;
 477         unsigned long flag;
 478
 479         if (!vdev) {
 480                 pr_err("could not get virtual device");
 481                 /* BUG(); */
 482                 return;
 483         }
 484
 485         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 486
 487         spin_lock_irqsave(&vdev->priv_lock, flag);
 488
 489         if (!priv) {
 490                 dev_err(&urb->dev->dev, "malloc vhci_priv\n");
 491                 spin_unlock_irqrestore(&vdev->priv_lock, flag);
 492                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 493                 return;
 494         }
 495
 496         priv->seqnum = atomic_inc_return(&the_controller->seqnum);
 497         if (priv->seqnum == 0xffff)
 498                 dev_info(&urb->dev->dev, "seqnum max\n");
 499
 500         priv->vdev = vdev;
 501         priv->urb = urb;
 502
 503         urb->hcpriv = (void *) priv;
 504
 505         list_add_tail(&priv->list, &vdev->priv_tx);
 506
 507         wake_up(&vdev->waitq_tx);
 508         spin_unlock_irqrestore(&vdev->priv_lock, flag);
 509 }
 510
 511 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 512                             gfp_t mem_flags)
 513 {
 514         struct device *dev = &urb->dev->dev;
 515         int ret = 0;
 516         unsigned long flags;
 517         struct vhci_device *vdev;
 518
 519         /* patch to usb_sg_init() is in 2.5.60 */
 520         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 521
 522         spin_lock_irqsave(&the_controller->lock, flags);
 523
 524         if (urb->status != -EINPROGRESS) {
 525                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 526                 spin_unlock_irqrestore(&the_controller->lock, flags);
 527                 return urb->status;
 528         }
 529
 530         vdev = port_to_vdev(urb->dev->portnum-1);
 531
 532         /* refuse enqueue for dead connection */
 533         spin_lock(&vdev->ud.lock);
 534         if (vdev->ud.status == VDEV_ST_NULL ||
 535             vdev->ud.status == VDEV_ST_ERROR) {
 536                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 537                 spin_unlock(&vdev->ud.lock);
 538                 spin_unlock_irqrestore(&the_controller->lock, flags);
 539                 return -ENODEV;
 540         }
 541         spin_unlock(&vdev->ud.lock);
 542
 543         ret = usb_hcd_link_urb_to_ep(hcd, urb);
 544         if (ret)
 545                 goto no_need_unlink;
 546
 547         /*
 548          * The enumeration process is as follows;
 549          *
 550          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 551          *     to get max packet length of default pipe
 552          *
 553          *  2. Set_Address request to DevAddr(0) EndPoint(0)
 554          *
 555          */
 556         if (usb_pipedevice(urb->pipe) == 0) {
 557                 __u8 type = usb_pipetype(urb->pipe);
 558                 struct usb_ctrlrequest *ctrlreq =
 559                         (struct usb_ctrlrequest *) urb->setup_packet;
 560
 561                 if (type != PIPE_CONTROL || !ctrlreq) {
 562                         dev_err(dev, "invalid request to devnum 0\n");
 563                         ret = -EINVAL;
 564                         goto no_need_xmit;
 565                 }
 566
 567                 switch (ctrlreq->bRequest) {
 568                 case USB_REQ_SET_ADDRESS:
 569                         /* set_address may come when a device is reset */
 570                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
 571                                  ctrlreq->wValue, vdev->rhport);
 572
 573                         if (vdev->udev)
 574                                 usb_put_dev(vdev->udev);
 575                         vdev->udev = usb_get_dev(urb->dev);
 576
 577                         spin_lock(&vdev->ud.lock);
 578                         vdev->ud.status = VDEV_ST_USED;
 579                         spin_unlock(&vdev->ud.lock);
 580
 581                         if (urb->status == -EINPROGRESS) {
 582                                 /* This request is successfully completed. */
 583                                 /* If not -EINPROGRESS, possibly unlinked. */
 584                                 urb->status = 0;
 585                         }
 586
 587                         goto no_need_xmit;
 588
 589                 case USB_REQ_GET_DESCRIPTOR:
 590                         if (ctrlreq->wValue == (USB_DT_DEVICE << 8))
 591                                 usbip_dbg_vhci_hc("Not yet?: "
 592                                                   "Get_Descriptor to device 0 "
 593                                                   "(get max pipe size)\n");
 594
 595                         if (vdev->udev)
 596                                 usb_put_dev(vdev->udev);
 597                         vdev->udev = usb_get_dev(urb->dev);
 598                         goto out;
 599
 600                 default:
 601                         /* NOT REACHED */
 602                         dev_err(dev, "invalid request to devnum 0 bRequest %u, "
 603                                 "wValue %u\n", ctrlreq->bRequest,
 604                                 ctrlreq->wValue);
 605                         ret =  -EINVAL;
 606                         goto no_need_xmit;
 607                 }
 608
 609         }
 610
 611 out:
 612         vhci_tx_urb(urb);
 613         spin_unlock_irqrestore(&the_controller->lock, flags);
 614
 615         return 0;
 616
 617 no_need_xmit:
 618         usb_hcd_unlink_urb_from_ep(hcd, urb);
 619 no_need_unlink:
 620         spin_unlock_irqrestore(&the_controller->lock, flags);
 621         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 622         return ret;
 623 }
 624
 625 /*
 626  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 627  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 628  * back its urb. For the driver unlinking the urb, the content of the urb is
 629  * not important, but the calling to its completion handler is important; the
 630  * completion of unlinking is notified by the completion handler.
 631  *
 632  *
 633  * CLIENT SIDE
 634  *
 635  * - When vhci_hcd receives RET_SUBMIT,
 636  *
 637  *      - case 1a). the urb of the pdu is not unlinking.
 638  *              - normal case
 639  *              => just give back the urb
 640  *
 641  *      - case 1b). the urb of the pdu is unlinking.
 642  *              - usbip.ko will return a reply of the unlinking request.
 643  *              => give back the urb now and go to case 2b).
 644  *
 645  * - When vhci_hcd receives RET_UNLINK,
 646  *
 647  *      - case 2a). a submit request is still pending in vhci_hcd.
 648  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 649  *                completed there.
 650  *              => free a pending submit request
 651  *              => notify unlink completeness by giving back the urb
 652  *
 653  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 654  *              - urb was already given back to the core driver.
 655  *              => do not give back the urb
 656  *
 657  *
 658  * SERVER SIDE
 659  *
 660  * - When usbip receives CMD_UNLINK,
 661  *
 662  *      - case 3a). the urb of the unlink request is now in submission.
 663  *              => do usb_unlink_urb().
 664  *              => after the unlink is completed, send RET_UNLINK.
 665  *
 666  *      - case 3b). the urb of the unlink request is not in submission.
 667  *              - may be already completed or never be received
 668  *              => send RET_UNLINK
 669  *
 670  */
 671 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 672 {
 673         unsigned long flags;
 674         struct vhci_priv *priv;
 675         struct vhci_device *vdev;
 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                 list_del(&priv->list);
 706                 kfree(priv);
 707                 urb->hcpriv = NULL;
 708
 709                 spin_unlock_irqrestore(&vdev->priv_lock, flags2);
 710
 711                 /*
 712                  * If tcp connection is alive, we have sent CMD_UNLINK.
 713                  * vhci_rx will receive RET_UNLINK and give back the URB.
 714                  * Otherwise, we give back it here.
 715                  */
 716                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 717
 718                 spin_unlock_irqrestore(&the_controller->lock, flags);
 719                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 720                                      urb->status);
 721                 spin_lock_irqsave(&the_controller->lock, flags);
 722
 723         } else {
 724                 /* tcp connection is alive */
 725                 unsigned long flags2;
 726                 struct vhci_unlink *unlink;
 727
 728                 spin_lock_irqsave(&vdev->priv_lock, flags2);
 729
 730                 /* setup CMD_UNLINK pdu */
 731                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 732                 if (!unlink) {
 733                         pr_err("malloc vhci_unlink\n");
 734                         spin_unlock_irqrestore(&vdev->priv_lock, flags2);
 735                         spin_unlock_irqrestore(&the_controller->lock, flags);
 736                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 737                         return -ENOMEM;
 738                 }
 739
 740                 unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
 741                 if (unlink->seqnum == 0xffff)
 742                         pr_info("seqnum max\n");
 743
 744                 unlink->unlink_seqnum = priv->seqnum;
 745
 746                 /* send cmd_unlink and try to cancel the pending URB in the
 747                  * peer */
 748                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 749                 wake_up(&vdev->waitq_tx);
 750
 751                 spin_unlock_irqrestore(&vdev->priv_lock, flags2);
 752         }
 753
 754         spin_unlock_irqrestore(&the_controller->lock, flags);
 755
 756         usbip_dbg_vhci_hc("leave\n");
 757         return 0;
 758 }
 759
 760 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 761 {
 762         struct vhci_unlink *unlink, *tmp;
 763
 764         spin_lock(&vdev->priv_lock);
 765
 766         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 767                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 768                 list_del(&unlink->list);
 769                 kfree(unlink);
 770         }
 771
 772         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 773                 struct urb *urb;
 774
 775                 /* give back URB of unanswered unlink request */
 776                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 777
 778                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 779                 if (!urb) {
 780                         pr_info("the urb (seqnum %lu) was already given back\n",
 781                                 unlink->unlink_seqnum);
 782                         list_del(&unlink->list);
 783                         kfree(unlink);
 784                         continue;
 785                 }
 786
 787                 urb->status = -ENODEV;
 788
 789                 spin_lock(&the_controller->lock);
 790                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 791                 spin_unlock(&the_controller->lock);
 792
 793                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 794                                      urb->status);
 795
 796                 list_del(&unlink->list);
 797                 kfree(unlink);
 798         }
 799
 800         spin_unlock(&vdev->priv_lock);
 801 }
 802
 803 /*
 804  * The important thing is that only one context begins cleanup.
 805  * This is why error handling and cleanup become simple.
 806  * We do not want to consider race condition as possible.
 807  */
 808 static void vhci_shutdown_connection(struct usbip_device *ud)
 809 {
 810         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 811
 812         /* need this? see stub_dev.c */
 813         if (ud->tcp_socket) {
 814                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 815                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 816         }
 817
 818         /* kill threads related to this sdev, if v.c. exists */
 819         if (vdev->ud.tcp_rx && !task_is_dead(vdev->ud.tcp_rx))
 820                 kthread_stop(vdev->ud.tcp_rx);
 821         if (vdev->ud.tcp_tx && !task_is_dead(vdev->ud.tcp_tx))
 822                 kthread_stop(vdev->ud.tcp_tx);
 823
 824         pr_info("stop threads\n");
 825
 826         /* active connection is closed */
 827         if (vdev->ud.tcp_socket != NULL) {
 828                 sock_release(vdev->ud.tcp_socket);
 829                 vdev->ud.tcp_socket = NULL;
 830         }
 831         pr_info("release socket\n");
 832
 833         vhci_device_unlink_cleanup(vdev);
 834
 835         /*
 836          * rh_port_disconnect() is a trigger of ...
 837          *   usb_disable_device():
 838          *      disable all the endpoints for a USB device.
 839          *   usb_disable_endpoint():
 840          *      disable endpoints. pending urbs are unlinked(dequeued).
 841          *
 842          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 843          * deteched device should release used urbs in a cleanup function(i.e.
 844          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 845          * pushed urbs and their private data in this function.
 846          *
 847          * NOTE: vhci_dequeue() must be considered carefully. When shutdowning
 848          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 849          * gives back pushed urbs and frees their private data by request of
 850          * the cleanup function of a USB driver. When unlinking a urb with an
 851          * active connection, vhci_dequeue() does not give back the urb which
 852          * is actually given back by vhci_rx after receiving its return pdu.
 853          *
 854          */
 855         rh_port_disconnect(vdev->rhport);
 856
 857         pr_info("disconnect device\n");
 858 }
 859
 860
 861 static void vhci_device_reset(struct usbip_device *ud)
 862 {
 863         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 864
 865         spin_lock(&ud->lock);
 866
 867         vdev->speed  = 0;
 868         vdev->devid  = 0;
 869
 870         if (vdev->udev)
 871                 usb_put_dev(vdev->udev);
 872         vdev->udev = NULL;
 873
 874         ud->tcp_socket = NULL;
 875         ud->status = VDEV_ST_NULL;
 876
 877         spin_unlock(&ud->lock);
 878 }
 879
 880 static void vhci_device_unusable(struct usbip_device *ud)
 881 {
 882         spin_lock(&ud->lock);
 883         ud->status = VDEV_ST_ERROR;
 884         spin_unlock(&ud->lock);
 885 }
 886
 887 static void vhci_device_init(struct vhci_device *vdev)
 888 {
 889         memset(vdev, 0, sizeof(*vdev));
 890
 891         vdev->ud.side   = USBIP_VHCI;
 892         vdev->ud.status = VDEV_ST_NULL;
 893         /* vdev->ud.lock   = SPIN_LOCK_UNLOCKED; */
 894         spin_lock_init(&vdev->ud.lock);
 895
 896         INIT_LIST_HEAD(&vdev->priv_rx);
 897         INIT_LIST_HEAD(&vdev->priv_tx);
 898         INIT_LIST_HEAD(&vdev->unlink_tx);
 899         INIT_LIST_HEAD(&vdev->unlink_rx);
 900         /* vdev->priv_lock = SPIN_LOCK_UNLOCKED; */
 901         spin_lock_init(&vdev->priv_lock);
 902
 903         init_waitqueue_head(&vdev->waitq_tx);
 904
 905         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 906         vdev->ud.eh_ops.reset = vhci_device_reset;
 907         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 908
 909         usbip_start_eh(&vdev->ud);
 910 }
 911
 912 static int vhci_start(struct usb_hcd *hcd)
 913 {
 914         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 915         int rhport;
 916         int err = 0;
 917
 918         usbip_dbg_vhci_hc("enter vhci_start\n");
 919
 920         /* initialize private data of usb_hcd */
 921
 922         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 923                 struct vhci_device *vdev = &vhci->vdev[rhport];
 924                 vhci_device_init(vdev);
 925                 vdev->rhport = rhport;
 926         }
 927
 928         atomic_set(&vhci->seqnum, 0);
 929         spin_lock_init(&vhci->lock);
 930
 931         hcd->power_budget = 0; /* no limit */
 932         hcd->state  = HC_STATE_RUNNING;
 933         hcd->uses_new_polling = 1;
 934
 935         /* vhci_hcd is now ready to be controlled through sysfs */
 936         err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 937         if (err) {
 938                 pr_err("create sysfs files\n");
 939                 return err;
 940         }
 941
 942         return 0;
 943 }
 944
 945 static void vhci_stop(struct usb_hcd *hcd)
 946 {
 947         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 948         int rhport = 0;
 949
 950         usbip_dbg_vhci_hc("stop VHCI controller\n");
 951
 952         /* 1. remove the userland interface of vhci_hcd */
 953         sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 954
 955         /* 2. shutdown all the ports of vhci_hcd */
 956         for (rhport = 0 ; rhport < VHCI_NPORTS; rhport++) {
 957                 struct vhci_device *vdev = &vhci->vdev[rhport];
 958
 959                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
 960                 usbip_stop_eh(&vdev->ud);
 961         }
 962 }
 963
 964 static int vhci_get_frame_number(struct usb_hcd *hcd)
 965 {
 966         pr_err("Not yet implemented\n");
 967         return 0;
 968 }
 969
 970 #ifdef CONFIG_PM
 971
 972 /* FIXME: suspend/resume */
 973 static int vhci_bus_suspend(struct usb_hcd *hcd)
 974 {
 975         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 976
 977         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 978
 979         spin_lock_irq(&vhci->lock);
 980         /* vhci->rh_state = DUMMY_RH_SUSPENDED;
 981          * set_link_state(vhci); */
 982         hcd->state = HC_STATE_SUSPENDED;
 983         spin_unlock_irq(&vhci->lock);
 984
 985         return 0;
 986 }
 987
 988 static int vhci_bus_resume(struct usb_hcd *hcd)
 989 {
 990         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 991         int rc = 0;
 992
 993         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 994
 995         spin_lock_irq(&vhci->lock);
 996         if (!HCD_HW_ACCESSIBLE(hcd)) {
 997                 rc = -ESHUTDOWN;
 998         } else {
 999                 /* vhci->rh_state = DUMMY_RH_RUNNING;
1000                  * set_link_state(vhci);
1001                  * if (!list_empty(&vhci->urbp_list))
1002                  *      mod_timer(&vhci->timer, jiffies); */
1003                 hcd->state = HC_STATE_RUNNING;
1004         }
1005         spin_unlock_irq(&vhci->lock);
1006
1007         return rc;
1008 }
1009
1010 #else
1011
1012 #define vhci_bus_suspend      NULL
1013 #define vhci_bus_resume       NULL
1014 #endif
1015
1016 static struct hc_driver vhci_hc_driver = {
1017         .description    = driver_name,
1018         .product_desc   = driver_desc,
1019         .hcd_priv_size  = sizeof(struct vhci_hcd),
1020
1021         .flags          = HCD_USB2,
1022
1023         .start          = vhci_start,
1024         .stop           = vhci_stop,
1025
1026         .urb_enqueue    = vhci_urb_enqueue,
1027         .urb_dequeue    = vhci_urb_dequeue,
1028
1029         .get_frame_number = vhci_get_frame_number,
1030
1031         .hub_status_data = vhci_hub_status,
1032         .hub_control    = vhci_hub_control,
1033         .bus_suspend    = vhci_bus_suspend,
1034         .bus_resume     = vhci_bus_resume,
1035 };
1036
1037 static int vhci_hcd_probe(struct platform_device *pdev)
1038 {
1039         struct usb_hcd          *hcd;
1040         int                     ret;
1041
1042         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1043
1044         /* will be removed */
1045         if (pdev->dev.dma_mask) {
1046                 dev_info(&pdev->dev, "vhci_hcd DMA not supported\n");
1047                 return -EINVAL;
1048         }
1049
1050         /*
1051          * Allocate and initialize hcd.
1052          * Our private data is also allocated automatically.
1053          */
1054         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1055         if (!hcd) {
1056                 pr_err("create hcd failed\n");
1057                 return -ENOMEM;
1058         }
1059         hcd->has_tt = 1;
1060
1061         /* this is private data for vhci_hcd */
1062         the_controller = hcd_to_vhci(hcd);
1063
1064         /*
1065          * Finish generic HCD structure initialization and register.
1066          * Call the driver's reset() and start() routines.
1067          */
1068         ret = usb_add_hcd(hcd, 0, 0);
1069         if (ret != 0) {
1070                 pr_err("usb_add_hcd failed %d\n", ret);
1071                 usb_put_hcd(hcd);
1072                 the_controller = NULL;
1073                 return ret;
1074         }
1075
1076         usbip_dbg_vhci_hc("bye\n");
1077         return 0;
1078 }
1079
1080 static int vhci_hcd_remove(struct platform_device *pdev)
1081 {
1082         struct usb_hcd  *hcd;
1083
1084         hcd = platform_get_drvdata(pdev);
1085         if (!hcd)
1086                 return 0;
1087
1088         /*
1089          * Disconnects the root hub,
1090          * then reverses the effects of usb_add_hcd(),
1091          * invoking the HCD's stop() methods.
1092          */
1093         usb_remove_hcd(hcd);
1094         usb_put_hcd(hcd);
1095         the_controller = NULL;
1096
1097         return 0;
1098 }
1099
1100 #ifdef CONFIG_PM
1101
1102 /* what should happen for USB/IP under suspend/resume? */
1103 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1104 {
1105         struct usb_hcd *hcd;
1106         int rhport = 0;
1107         int connected = 0;
1108         int ret = 0;
1109
1110         hcd = platform_get_drvdata(pdev);
1111
1112         spin_lock(&the_controller->lock);
1113
1114         for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1115                 if (the_controller->port_status[rhport] &
1116                     USB_PORT_STAT_CONNECTION)
1117                         connected += 1;
1118
1119         spin_unlock(&the_controller->lock);
1120
1121         if (connected > 0) {
1122                 dev_info(&pdev->dev, "We have %d active connection%s. Do not "
1123                          "suspend.\n", connected, (connected == 1 ? "" : "s"));
1124                 ret =  -EBUSY;
1125         } else {
1126                 dev_info(&pdev->dev, "suspend vhci_hcd");
1127                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1128         }
1129
1130         return ret;
1131 }
1132
1133 static int vhci_hcd_resume(struct platform_device *pdev)
1134 {
1135         struct usb_hcd *hcd;
1136
1137         dev_dbg(&pdev->dev, "%s\n", __func__);
1138
1139         hcd = platform_get_drvdata(pdev);
1140         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1141         usb_hcd_poll_rh_status(hcd);
1142
1143         return 0;
1144 }
1145
1146 #else
1147
1148 #define vhci_hcd_suspend        NULL
1149 #define vhci_hcd_resume         NULL
1150
1151 #endif
1152
1153 static struct platform_driver vhci_driver = {
1154         .probe  = vhci_hcd_probe,
1155         .remove = __devexit_p(vhci_hcd_remove),
1156         .suspend = vhci_hcd_suspend,
1157         .resume = vhci_hcd_resume,
1158         .driver = {
1159                 .name = (char *) driver_name,
1160                 .owner = THIS_MODULE,
1161         },
1162 };
1163
1164 /*
1165  * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1166  * We need to add this virtual device as a platform device arbitrarily:
1167  *      1. platform_device_register()
1168  */
1169 static void the_pdev_release(struct device *dev)
1170 {
1171         return;
1172 }
1173
1174 static struct platform_device the_pdev = {
1175         /* should be the same name as driver_name */
1176         .name = (char *) driver_name,
1177         .id = -1,
1178         .dev = {
1179                 /* .driver = &vhci_driver, */
1180                 .release = the_pdev_release,
1181         },
1182 };
1183
1184 static int __init vhci_hcd_init(void)
1185 {
1186         int ret;
1187
1188         if (usb_disabled())
1189                 return -ENODEV;
1190
1191         ret = platform_driver_register(&vhci_driver);
1192         if (ret < 0)
1193                 goto err_driver_register;
1194
1195         ret = platform_device_register(&the_pdev);
1196         if (ret < 0)
1197                 goto err_platform_device_register;
1198
1199         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1200         return ret;
1201
1202 err_platform_device_register:
1203         platform_driver_unregister(&vhci_driver);
1204 err_driver_register:
1205         return ret;
1206 }
1207
1208 static void __exit vhci_hcd_exit(void)
1209 {
1210         platform_device_unregister(&the_pdev);
1211         platform_driver_unregister(&vhci_driver);
1212 }
1213
1214 module_init(vhci_hcd_init);
1215 module_exit(vhci_hcd_exit);
1216
1217 MODULE_AUTHOR(DRIVER_AUTHOR);
1218 MODULE_DESCRIPTION(DRIVER_DESC);
1219 MODULE_LICENSE("GPL");
1220 MODULE_VERSION(USBIP_VERSION);