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