drivers/usb/usbip/vhci_hcd.c

   1 /*
   2  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   3  *
   4  * This is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17  * USA.
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/file.h>
  22 #include <linux/kernel.h>
  23 #include <linux/kthread.h>
  24 #include <linux/module.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/slab.h>
  27
  28 #include "usbip_common.h"
  29 #include "vhci.h"
  30
  31 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
  32 #define DRIVER_DESC "USB/IP 'Virtual' Host Controller (VHCI) Driver"
  33
  34 /*
  35  * TODO
  36  *      - update root hub emulation
  37  *      - move the emulation code to userland ?
  38  *              porting to other operating systems
  39  *              minimize kernel code
  40  *      - add suspend/resume code
  41  *      - clean up everything
  42  */
  43
  44 /* See usb gadget dummy hcd */
  45
  46 static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
  47 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
  48                             u16 wIndex, char *buff, u16 wLength);
  49 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
  50                             gfp_t mem_flags);
  51 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
  52 static int vhci_start(struct usb_hcd *vhci_hcd);
  53 static void vhci_stop(struct usb_hcd *hcd);
  54 static int vhci_get_frame_number(struct usb_hcd *hcd);
  55
  56 static const char driver_name[] = "vhci_hcd";
  57 static const char driver_desc[] = "USB/IP Virtual Host Controller";
  58
  59 struct vhci_hcd *the_controller;
  60
  61 static const char * const bit_desc[] = {
  62         "CONNECTION",           /*0*/
  63         "ENABLE",               /*1*/
  64         "SUSPEND",              /*2*/
  65         "OVER_CURRENT",         /*3*/
  66         "RESET",                /*4*/
  67         "R5",                   /*5*/
  68         "R6",                   /*6*/
  69         "R7",                   /*7*/
  70         "POWER",                /*8*/
  71         "LOWSPEED",             /*9*/
  72         "HIGHSPEED",            /*10*/
  73         "PORT_TEST",            /*11*/
  74         "INDICATOR",            /*12*/
  75         "R13",                  /*13*/
  76         "R14",                  /*14*/
  77         "R15",                  /*15*/
  78         "C_CONNECTION",         /*16*/
  79         "C_ENABLE",             /*17*/
  80         "C_SUSPEND",            /*18*/
  81         "C_OVER_CURRENT",       /*19*/
  82         "C_RESET",              /*20*/
  83         "R21",                  /*21*/
  84         "R22",                  /*22*/
  85         "R23",                  /*23*/
  86         "R24",                  /*24*/
  87         "R25",                  /*25*/
  88         "R26",                  /*26*/
  89         "R27",                  /*27*/
  90         "R28",                  /*28*/
  91         "R29",                  /*29*/
  92         "R30",                  /*30*/
  93         "R31",                  /*31*/
  94 };
  95
  96 static void dump_port_status_diff(u32 prev_status, u32 new_status)
  97 {
  98         int i = 0;
  99         u32 bit = 1;
 100
 101         pr_debug("status prev -> new: %08x -> %08x\n", prev_status, new_status);
 102         while (bit) {
 103                 u32 prev = prev_status & bit;
 104                 u32 new = new_status & bit;
 105                 char change;
 106
 107                 if (!prev && new)
 108                         change = '+';
 109                 else if (prev && !new)
 110                         change = '-';
 111                 else
 112                         change = ' ';
 113
 114                 if (prev || new)
 115                         pr_debug(" %c%s\n", change, bit_desc[i]);
 116                 bit <<= 1;
 117                 i++;
 118         }
 119         pr_debug("\n");
 120 }
 121
 122 void rh_port_connect(int rhport, enum usb_device_speed speed)
 123 {
 124         unsigned long   flags;
 125
 126         usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
 127
 128         spin_lock_irqsave(&the_controller->lock, flags);
 129
 130         the_controller->port_status[rhport] |= USB_PORT_STAT_CONNECTION
 131                 | (1 << USB_PORT_FEAT_C_CONNECTION);
 132
 133         switch (speed) {
 134         case USB_SPEED_HIGH:
 135                 the_controller->port_status[rhport] |= USB_PORT_STAT_HIGH_SPEED;
 136                 break;
 137         case USB_SPEED_LOW:
 138                 the_controller->port_status[rhport] |= USB_PORT_STAT_LOW_SPEED;
 139                 break;
 140         default:
 141                 break;
 142         }
 143
 144         spin_unlock_irqrestore(&the_controller->lock, flags);
 145
 146         usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
 147 }
 148
 149 static void rh_port_disconnect(int rhport)
 150 {
 151         unsigned long   flags;
 152
 153         usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
 154
 155         spin_lock_irqsave(&the_controller->lock, flags);
 156
 157         the_controller->port_status[rhport] &= ~USB_PORT_STAT_CONNECTION;
 158         the_controller->port_status[rhport] |=
 159                                         (1 << USB_PORT_FEAT_C_CONNECTION);
 160
 161         spin_unlock_irqrestore(&the_controller->lock, flags);
 162         usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
 163 }
 164
 165 #define PORT_C_MASK                             \
 166         ((USB_PORT_STAT_C_CONNECTION            \
 167           | USB_PORT_STAT_C_ENABLE              \
 168           | USB_PORT_STAT_C_SUSPEND             \
 169           | USB_PORT_STAT_C_OVERCURRENT         \
 170           | USB_PORT_STAT_C_RESET) << 16)
 171
 172 /*
 173  * Returns 0 if the status hasn't changed, or the number of bytes in buf.
 174  * Ports are 0-indexed from the HCD point of view,
 175  * and 1-indexed from the USB core pointer of view.
 176  *
 177  * @buf: a bitmap to show which port status has been changed.
 178  *  bit  0: reserved
 179  *  bit  1: the status of port 0 has been changed.
 180  *  bit  2: the status of port 1 has been changed.
 181  *  ...
 182  */
 183 static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
 184 {
 185         struct vhci_hcd *vhci;
 186         int             retval;
 187         int             rhport;
 188         int             changed = 0;
 189         unsigned long   flags;
 190
 191         retval = DIV_ROUND_UP(VHCI_NPORTS + 1, 8);
 192         memset(buf, 0, retval);
 193
 194         vhci = hcd_to_vhci(hcd);
 195
 196         spin_lock_irqsave(&vhci->lock, flags);
 197         if (!HCD_HW_ACCESSIBLE(hcd)) {
 198                 usbip_dbg_vhci_rh("hw accessible flag not on?\n");
 199                 goto done;
 200         }
 201
 202         /* check pseudo status register for each port */
 203         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 204                 if ((vhci->port_status[rhport] & PORT_C_MASK)) {
 205                         /* The status of a port has been changed, */
 206                         usbip_dbg_vhci_rh("port %d status changed\n", rhport);
 207
 208                         buf[(rhport + 1) / 8] |= 1 << (rhport + 1) % 8;
 209                         changed = 1;
 210                 }
 211         }
 212
 213         if ((hcd->state == HC_STATE_SUSPENDED) && (changed == 1))
 214                 usb_hcd_resume_root_hub(hcd);
 215
 216 done:
 217         spin_unlock_irqrestore(&vhci->lock, flags);
 218         return changed ? retval : 0;
 219 }
 220
 221 static inline void hub_descriptor(struct usb_hub_descriptor *desc)
 222 {
 223         memset(desc, 0, sizeof(*desc));
 224         desc->bDescriptorType = USB_DT_HUB;
 225         desc->bDescLength = 9;
 226         desc->wHubCharacteristics = cpu_to_le16(
 227                 HUB_CHAR_INDV_PORT_LPSM | HUB_CHAR_COMMON_OCPM);
 228         desc->bNbrPorts = VHCI_NPORTS;
 229         desc->u.hs.DeviceRemovable[0] = 0xff;
 230         desc->u.hs.DeviceRemovable[1] = 0xff;
 231 }
 232
 233 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 234                             u16 wIndex, char *buf, u16 wLength)
 235 {
 236         struct vhci_hcd *dum;
 237         int             retval = 0;
 238         int             rhport;
 239         unsigned long   flags;
 240
 241         u32 prev_port_status[VHCI_NPORTS];
 242
 243         if (!HCD_HW_ACCESSIBLE(hcd))
 244                 return -ETIMEDOUT;
 245
 246         /*
 247          * NOTE:
 248          * wIndex shows the port number and begins from 1.
 249          */
 250         usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 251                           wIndex);
 252         if (wIndex > VHCI_NPORTS)
 253                 pr_err("invalid port number %d\n", wIndex);
 254         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 255
 256         dum = hcd_to_vhci(hcd);
 257
 258         spin_lock_irqsave(&dum->lock, flags);
 259
 260         /* store old status and compare now and old later */
 261         if (usbip_dbg_flag_vhci_rh) {
 262                 memcpy(prev_port_status, dum->port_status,
 263                         sizeof(prev_port_status));
 264         }
 265
 266         switch (typeReq) {
 267         case ClearHubFeature:
 268                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
 269                 break;
 270         case ClearPortFeature:
 271                 switch (wValue) {
 272                 case USB_PORT_FEAT_SUSPEND:
 273                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
 274                                 /* 20msec signaling */
 275                                 dum->resuming = 1;
 276                                 dum->re_timeout =
 277                                         jiffies + msecs_to_jiffies(20);
 278                         }
 279                         break;
 280                 case USB_PORT_FEAT_POWER:
 281                         usbip_dbg_vhci_rh(
 282                                 " ClearPortFeature: USB_PORT_FEAT_POWER\n");
 283                         dum->port_status[rhport] = 0;
 284                         dum->resuming = 0;
 285                         break;
 286                 case USB_PORT_FEAT_C_RESET:
 287                         usbip_dbg_vhci_rh(
 288                                 " ClearPortFeature: USB_PORT_FEAT_C_RESET\n");
 289                         switch (dum->vdev[rhport].speed) {
 290                         case USB_SPEED_HIGH:
 291                                 dum->port_status[rhport] |=
 292                                         USB_PORT_STAT_HIGH_SPEED;
 293                                 break;
 294                         case USB_SPEED_LOW:
 295                                 dum->port_status[rhport] |=
 296                                         USB_PORT_STAT_LOW_SPEED;
 297                                 break;
 298                         default:
 299                                 break;
 300                         }
 301                 default:
 302                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 303                                           wValue);
 304                         dum->port_status[rhport] &= ~(1 << wValue);
 305                         break;
 306                 }
 307                 break;
 308         case GetHubDescriptor:
 309                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 310                 hub_descriptor((struct usb_hub_descriptor *) buf);
 311                 break;
 312         case GetHubStatus:
 313                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 314                 *(__le32 *) buf = cpu_to_le32(0);
 315                 break;
 316         case GetPortStatus:
 317                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 318                 if (wIndex > VHCI_NPORTS || wIndex < 1) {
 319                         pr_err("invalid port number %d\n", wIndex);
 320                         retval = -EPIPE;
 321                 }
 322
 323                 /* we do not care about resume. */
 324
 325                 /* whoever resets or resumes must GetPortStatus to
 326                  * complete it!!
 327                  */
 328                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 329                         dum->port_status[rhport] |=
 330                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 331                         dum->port_status[rhport] &=
 332                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 333                         dum->resuming = 0;
 334                         dum->re_timeout = 0;
 335                 }
 336
 337                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 338                     0 && time_after(jiffies, dum->re_timeout)) {
 339                         dum->port_status[rhport] |=
 340                                 (1 << USB_PORT_FEAT_C_RESET);
 341                         dum->port_status[rhport] &=
 342                                 ~(1 << USB_PORT_FEAT_RESET);
 343                         dum->re_timeout = 0;
 344
 345                         if (dum->vdev[rhport].ud.status ==
 346                             VDEV_ST_NOTASSIGNED) {
 347                                 usbip_dbg_vhci_rh(
 348                                         " enable rhport %d (status %u)\n",
 349                                         rhport,
 350                                         dum->vdev[rhport].ud.status);
 351                                 dum->port_status[rhport] |=
 352                                         USB_PORT_STAT_ENABLE;
 353                         }
 354                 }
 355                 ((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 356                 ((__le16 *) buf)[1] =
 357                         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(
 370                                 " SetPortFeature: USB_PORT_FEAT_SUSPEND\n");
 371                         break;
 372                 case USB_PORT_FEAT_RESET:
 373                         usbip_dbg_vhci_rh(
 374                                 " SetPortFeature: 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 flags;
 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         if (!priv) {
 444                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 445                 return;
 446         }
 447
 448         spin_lock_irqsave(&vdev->priv_lock, flags);
 449
 450         priv->seqnum = atomic_inc_return(&the_controller->seqnum);
 451         if (priv->seqnum == 0xffff)
 452                 dev_info(&urb->dev->dev, "seqnum max\n");
 453
 454         priv->vdev = vdev;
 455         priv->urb = urb;
 456
 457         urb->hcpriv = (void *) priv;
 458
 459         list_add_tail(&priv->list, &vdev->priv_tx);
 460
 461         wake_up(&vdev->waitq_tx);
 462         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 463 }
 464
 465 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 466                             gfp_t mem_flags)
 467 {
 468         struct device *dev = &urb->dev->dev;
 469         int ret = 0;
 470         struct vhci_device *vdev;
 471         unsigned long flags;
 472
 473         usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
 474                           hcd, urb, mem_flags);
 475
 476         /* patch to usb_sg_init() is in 2.5.60 */
 477         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 478
 479         spin_lock_irqsave(&the_controller->lock, flags);
 480
 481         if (urb->status != -EINPROGRESS) {
 482                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 483                 spin_unlock_irqrestore(&the_controller->lock, flags);
 484                 return urb->status;
 485         }
 486
 487         vdev = port_to_vdev(urb->dev->portnum-1);
 488
 489         /* refuse enqueue for dead connection */
 490         spin_lock(&vdev->ud.lock);
 491         if (vdev->ud.status == VDEV_ST_NULL ||
 492             vdev->ud.status == VDEV_ST_ERROR) {
 493                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 494                 spin_unlock(&vdev->ud.lock);
 495                 spin_unlock_irqrestore(&the_controller->lock, flags);
 496                 return -ENODEV;
 497         }
 498         spin_unlock(&vdev->ud.lock);
 499
 500         ret = usb_hcd_link_urb_to_ep(hcd, urb);
 501         if (ret)
 502                 goto no_need_unlink;
 503
 504         /*
 505          * The enumeration process is as follows;
 506          *
 507          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 508          *     to get max packet length of default pipe
 509          *
 510          *  2. Set_Address request to DevAddr(0) EndPoint(0)
 511          *
 512          */
 513         if (usb_pipedevice(urb->pipe) == 0) {
 514                 __u8 type = usb_pipetype(urb->pipe);
 515                 struct usb_ctrlrequest *ctrlreq =
 516                         (struct usb_ctrlrequest *) urb->setup_packet;
 517
 518                 if (type != PIPE_CONTROL || !ctrlreq) {
 519                         dev_err(dev, "invalid request to devnum 0\n");
 520                         ret = -EINVAL;
 521                         goto no_need_xmit;
 522                 }
 523
 524                 switch (ctrlreq->bRequest) {
 525                 case USB_REQ_SET_ADDRESS:
 526                         /* set_address may come when a device is reset */
 527                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
 528                                  ctrlreq->wValue, vdev->rhport);
 529
 530                         usb_put_dev(vdev->udev);
 531                         vdev->udev = usb_get_dev(urb->dev);
 532
 533                         spin_lock(&vdev->ud.lock);
 534                         vdev->ud.status = VDEV_ST_USED;
 535                         spin_unlock(&vdev->ud.lock);
 536
 537                         if (urb->status == -EINPROGRESS) {
 538                                 /* This request is successfully completed. */
 539                                 /* If not -EINPROGRESS, possibly unlinked. */
 540                                 urb->status = 0;
 541                         }
 542
 543                         goto no_need_xmit;
 544
 545                 case USB_REQ_GET_DESCRIPTOR:
 546                         if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
 547                                 usbip_dbg_vhci_hc(
 548                                         "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
 549
 550                         usb_put_dev(vdev->udev);
 551                         vdev->udev = usb_get_dev(urb->dev);
 552                         goto out;
 553
 554                 default:
 555                         /* NOT REACHED */
 556                         dev_err(dev,
 557                                 "invalid request to devnum 0 bRequest %u, wValue %u\n",
 558                                 ctrlreq->bRequest,
 559                                 ctrlreq->wValue);
 560                         ret =  -EINVAL;
 561                         goto no_need_xmit;
 562                 }
 563
 564         }
 565
 566 out:
 567         vhci_tx_urb(urb);
 568         spin_unlock_irqrestore(&the_controller->lock, flags);
 569
 570         return 0;
 571
 572 no_need_xmit:
 573         usb_hcd_unlink_urb_from_ep(hcd, urb);
 574 no_need_unlink:
 575         spin_unlock_irqrestore(&the_controller->lock, flags);
 576         if (!ret)
 577                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller),
 578                                      urb, urb->status);
 579         return ret;
 580 }
 581
 582 /*
 583  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 584  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 585  * back its urb. For the driver unlinking the urb, the content of the urb is
 586  * not important, but the calling to its completion handler is important; the
 587  * completion of unlinking is notified by the completion handler.
 588  *
 589  *
 590  * CLIENT SIDE
 591  *
 592  * - When vhci_hcd receives RET_SUBMIT,
 593  *
 594  *      - case 1a). the urb of the pdu is not unlinking.
 595  *              - normal case
 596  *              => just give back the urb
 597  *
 598  *      - case 1b). the urb of the pdu is unlinking.
 599  *              - usbip.ko will return a reply of the unlinking request.
 600  *              => give back the urb now and go to case 2b).
 601  *
 602  * - When vhci_hcd receives RET_UNLINK,
 603  *
 604  *      - case 2a). a submit request is still pending in vhci_hcd.
 605  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 606  *                completed there.
 607  *              => free a pending submit request
 608  *              => notify unlink completeness by giving back the urb
 609  *
 610  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 611  *              - urb was already given back to the core driver.
 612  *              => do not give back the urb
 613  *
 614  *
 615  * SERVER SIDE
 616  *
 617  * - When usbip receives CMD_UNLINK,
 618  *
 619  *      - case 3a). the urb of the unlink request is now in submission.
 620  *              => do usb_unlink_urb().
 621  *              => after the unlink is completed, send RET_UNLINK.
 622  *
 623  *      - case 3b). the urb of the unlink request is not in submission.
 624  *              - may be already completed or never be received
 625  *              => send RET_UNLINK
 626  *
 627  */
 628 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 629 {
 630         struct vhci_priv *priv;
 631         struct vhci_device *vdev;
 632         unsigned long flags;
 633
 634         pr_info("dequeue a urb %p\n", urb);
 635
 636         spin_lock_irqsave(&the_controller->lock, flags);
 637
 638         priv = urb->hcpriv;
 639         if (!priv) {
 640                 /* URB was never linked! or will be soon given back by
 641                  * vhci_rx. */
 642                 spin_unlock_irqrestore(&the_controller->lock, flags);
 643                 return -EIDRM;
 644         }
 645
 646         {
 647                 int ret = 0;
 648
 649                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 650                 if (ret) {
 651                         spin_unlock_irqrestore(&the_controller->lock, flags);
 652                         return ret;
 653                 }
 654         }
 655
 656          /* send unlink request here? */
 657         vdev = priv->vdev;
 658
 659         if (!vdev->ud.tcp_socket) {
 660                 /* tcp connection is closed */
 661                 spin_lock(&vdev->priv_lock);
 662
 663                 pr_info("device %p seems to be disconnected\n", vdev);
 664                 list_del(&priv->list);
 665                 kfree(priv);
 666                 urb->hcpriv = NULL;
 667
 668                 spin_unlock(&vdev->priv_lock);
 669
 670                 /*
 671                  * If tcp connection is alive, we have sent CMD_UNLINK.
 672                  * vhci_rx will receive RET_UNLINK and give back the URB.
 673                  * Otherwise, we give back it here.
 674                  */
 675                 pr_info("gives back urb %p\n", urb);
 676
 677                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 678
 679                 spin_unlock_irqrestore(&the_controller->lock, flags);
 680                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 681                                      urb->status);
 682                 spin_lock_irqsave(&the_controller->lock, flags);
 683
 684         } else {
 685                 /* tcp connection is alive */
 686                 struct vhci_unlink *unlink;
 687
 688                 spin_lock(&vdev->priv_lock);
 689
 690                 /* setup CMD_UNLINK pdu */
 691                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 692                 if (!unlink) {
 693                         spin_unlock(&vdev->priv_lock);
 694                         spin_unlock_irqrestore(&the_controller->lock, flags);
 695                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 696                         return -ENOMEM;
 697                 }
 698
 699                 unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
 700                 if (unlink->seqnum == 0xffff)
 701                         pr_info("seqnum max\n");
 702
 703                 unlink->unlink_seqnum = priv->seqnum;
 704
 705                 pr_info("device %p seems to be still connected\n", vdev);
 706
 707                 /* send cmd_unlink and try to cancel the pending URB in the
 708                  * peer */
 709                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 710                 wake_up(&vdev->waitq_tx);
 711
 712                 spin_unlock(&vdev->priv_lock);
 713         }
 714
 715         spin_unlock_irqrestore(&the_controller->lock, flags);
 716
 717         usbip_dbg_vhci_hc("leave\n");
 718         return 0;
 719 }
 720
 721 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 722 {
 723         struct vhci_unlink *unlink, *tmp;
 724         unsigned long flags;
 725
 726         spin_lock_irqsave(&the_controller->lock, flags);
 727         spin_lock(&vdev->priv_lock);
 728
 729         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 730                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 731                 list_del(&unlink->list);
 732                 kfree(unlink);
 733         }
 734
 735         while (!list_empty(&vdev->unlink_rx)) {
 736                 struct urb *urb;
 737
 738                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 739                         list);
 740
 741                 /* give back URB of unanswered unlink request */
 742                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 743
 744                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 745                 if (!urb) {
 746                         pr_info("the urb (seqnum %lu) was already given back\n",
 747                                 unlink->unlink_seqnum);
 748                         list_del(&unlink->list);
 749                         kfree(unlink);
 750                         continue;
 751                 }
 752
 753                 urb->status = -ENODEV;
 754
 755                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 756
 757                 list_del(&unlink->list);
 758
 759                 spin_unlock(&vdev->priv_lock);
 760                 spin_unlock_irqrestore(&the_controller->lock, flags);
 761
 762                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 763                                      urb->status);
 764
 765                 spin_lock_irqsave(&the_controller->lock, flags);
 766                 spin_lock(&vdev->priv_lock);
 767
 768                 kfree(unlink);
 769         }
 770
 771         spin_unlock(&vdev->priv_lock);
 772         spin_unlock_irqrestore(&the_controller->lock, flags);
 773 }
 774
 775 /*
 776  * The important thing is that only one context begins cleanup.
 777  * This is why error handling and cleanup become simple.
 778  * We do not want to consider race condition as possible.
 779  */
 780 static void vhci_shutdown_connection(struct usbip_device *ud)
 781 {
 782         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 783
 784         /* need this? see stub_dev.c */
 785         if (ud->tcp_socket) {
 786                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 787                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 788         }
 789
 790         /* kill threads related to this sdev */
 791         if (vdev->ud.tcp_rx) {
 792                 kthread_stop_put(vdev->ud.tcp_rx);
 793                 vdev->ud.tcp_rx = NULL;
 794         }
 795         if (vdev->ud.tcp_tx) {
 796                 kthread_stop_put(vdev->ud.tcp_tx);
 797                 vdev->ud.tcp_tx = NULL;
 798         }
 799         pr_info("stop threads\n");
 800
 801         /* active connection is closed */
 802         if (vdev->ud.tcp_socket) {
 803                 sockfd_put(vdev->ud.tcp_socket);
 804                 vdev->ud.tcp_socket = NULL;
 805         }
 806         pr_info("release socket\n");
 807
 808         vhci_device_unlink_cleanup(vdev);
 809
 810         /*
 811          * rh_port_disconnect() is a trigger of ...
 812          *   usb_disable_device():
 813          *      disable all the endpoints for a USB device.
 814          *   usb_disable_endpoint():
 815          *      disable endpoints. pending urbs are unlinked(dequeued).
 816          *
 817          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 818          * detached device should release used urbs in a cleanup function (i.e.
 819          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 820          * pushed urbs and their private data in this function.
 821          *
 822          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 823          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 824          * gives back pushed urbs and frees their private data by request of
 825          * the cleanup function of a USB driver. When unlinking a urb with an
 826          * active connection, vhci_dequeue() does not give back the urb which
 827          * is actually given back by vhci_rx after receiving its return pdu.
 828          *
 829          */
 830         rh_port_disconnect(vdev->rhport);
 831
 832         pr_info("disconnect device\n");
 833 }
 834
 835
 836 static void vhci_device_reset(struct usbip_device *ud)
 837 {
 838         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 839         unsigned long flags;
 840
 841         spin_lock_irqsave(&ud->lock, flags);
 842
 843         vdev->speed  = 0;
 844         vdev->devid  = 0;
 845
 846         usb_put_dev(vdev->udev);
 847         vdev->udev = NULL;
 848
 849         if (ud->tcp_socket) {
 850                 sockfd_put(ud->tcp_socket);
 851                 ud->tcp_socket = NULL;
 852         }
 853         ud->status = VDEV_ST_NULL;
 854
 855         spin_unlock_irqrestore(&ud->lock, flags);
 856 }
 857
 858 static void vhci_device_unusable(struct usbip_device *ud)
 859 {
 860         unsigned long flags;
 861
 862         spin_lock_irqsave(&ud->lock, flags);
 863         ud->status = VDEV_ST_ERROR;
 864         spin_unlock_irqrestore(&ud->lock, flags);
 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
 903                 vhci_device_init(vdev);
 904                 vdev->rhport = rhport;
 905         }
 906
 907         atomic_set(&vhci->seqnum, 0);
 908         spin_lock_init(&vhci->lock);
 909
 910         hcd->power_budget = 0; /* no limit */
 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         dev_err_ratelimited(&hcd->self.root_hub->dev, "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         unsigned long flags;
 955
 956         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 957
 958         spin_lock_irqsave(&vhci->lock, flags);
 959         hcd->state = HC_STATE_SUSPENDED;
 960         spin_unlock_irqrestore(&vhci->lock, flags);
 961
 962         return 0;
 963 }
 964
 965 static int vhci_bus_resume(struct usb_hcd *hcd)
 966 {
 967         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 968         int rc = 0;
 969         unsigned long flags;
 970
 971         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 972
 973         spin_lock_irqsave(&vhci->lock, flags);
 974         if (!HCD_HW_ACCESSIBLE(hcd))
 975                 rc = -ESHUTDOWN;
 976         else
 977                 hcd->state = HC_STATE_RUNNING;
 978         spin_unlock_irqrestore(&vhci->lock, flags);
 979
 980         return rc;
 981 }
 982
 983 #else
 984
 985 #define vhci_bus_suspend      NULL
 986 #define vhci_bus_resume       NULL
 987 #endif
 988
 989 static struct hc_driver vhci_hc_driver = {
 990         .description    = driver_name,
 991         .product_desc   = driver_desc,
 992         .hcd_priv_size  = sizeof(struct vhci_hcd),
 993
 994         .flags          = HCD_USB2,
 995
 996         .start          = vhci_start,
 997         .stop           = vhci_stop,
 998
 999         .urb_enqueue    = vhci_urb_enqueue,
1000         .urb_dequeue    = vhci_urb_dequeue,
1001
1002         .get_frame_number = vhci_get_frame_number,
1003
1004         .hub_status_data = vhci_hub_status,
1005         .hub_control    = vhci_hub_control,
1006         .bus_suspend    = vhci_bus_suspend,
1007         .bus_resume     = vhci_bus_resume,
1008 };
1009
1010 static int vhci_hcd_probe(struct platform_device *pdev)
1011 {
1012         struct usb_hcd          *hcd;
1013         int                     ret;
1014
1015         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1016
1017         /*
1018          * Allocate and initialize hcd.
1019          * Our private data is also allocated automatically.
1020          */
1021         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1022         if (!hcd) {
1023                 pr_err("create hcd failed\n");
1024                 return -ENOMEM;
1025         }
1026         hcd->has_tt = 1;
1027
1028         /* this is private data for vhci_hcd */
1029         the_controller = hcd_to_vhci(hcd);
1030
1031         /*
1032          * Finish generic HCD structure initialization and register.
1033          * Call the driver's reset() and start() routines.
1034          */
1035         ret = usb_add_hcd(hcd, 0, 0);
1036         if (ret != 0) {
1037                 pr_err("usb_add_hcd failed %d\n", ret);
1038                 usb_put_hcd(hcd);
1039                 the_controller = NULL;
1040                 return ret;
1041         }
1042
1043         usbip_dbg_vhci_hc("bye\n");
1044         return 0;
1045 }
1046
1047 static int vhci_hcd_remove(struct platform_device *pdev)
1048 {
1049         struct usb_hcd  *hcd;
1050
1051         hcd = platform_get_drvdata(pdev);
1052         if (!hcd)
1053                 return 0;
1054
1055         /*
1056          * Disconnects the root hub,
1057          * then reverses the effects of usb_add_hcd(),
1058          * invoking the HCD's stop() methods.
1059          */
1060         usb_remove_hcd(hcd);
1061         usb_put_hcd(hcd);
1062         the_controller = NULL;
1063
1064         return 0;
1065 }
1066
1067 #ifdef CONFIG_PM
1068
1069 /* what should happen for USB/IP under suspend/resume? */
1070 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1071 {
1072         struct usb_hcd *hcd;
1073         int rhport = 0;
1074         int connected = 0;
1075         int ret = 0;
1076         unsigned long flags;
1077
1078         hcd = platform_get_drvdata(pdev);
1079
1080         spin_lock_irqsave(&the_controller->lock, flags);
1081
1082         for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1083                 if (the_controller->port_status[rhport] &
1084                     USB_PORT_STAT_CONNECTION)
1085                         connected += 1;
1086
1087         spin_unlock_irqrestore(&the_controller->lock, flags);
1088
1089         if (connected > 0) {
1090                 dev_info(&pdev->dev,
1091                          "We have %d active connection%s. Do not suspend.\n",
1092                          connected, (connected == 1 ? "" : "s"));
1093                 ret =  -EBUSY;
1094         } else {
1095                 dev_info(&pdev->dev, "suspend vhci_hcd");
1096                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1097         }
1098
1099         return ret;
1100 }
1101
1102 static int vhci_hcd_resume(struct platform_device *pdev)
1103 {
1104         struct usb_hcd *hcd;
1105
1106         dev_dbg(&pdev->dev, "%s\n", __func__);
1107
1108         hcd = platform_get_drvdata(pdev);
1109         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1110         usb_hcd_poll_rh_status(hcd);
1111
1112         return 0;
1113 }
1114
1115 #else
1116
1117 #define vhci_hcd_suspend        NULL
1118 #define vhci_hcd_resume         NULL
1119
1120 #endif
1121
1122 static struct platform_driver vhci_driver = {
1123         .probe  = vhci_hcd_probe,
1124         .remove = vhci_hcd_remove,
1125         .suspend = vhci_hcd_suspend,
1126         .resume = vhci_hcd_resume,
1127         .driver = {
1128                 .name = driver_name,
1129         },
1130 };
1131
1132 /*
1133  * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1134  * We need to add this virtual device as a platform device arbitrarily:
1135  *      1. platform_device_register()
1136  */
1137 static void the_pdev_release(struct device *dev)
1138 {
1139 }
1140
1141 static struct platform_device the_pdev = {
1142         /* should be the same name as driver_name */
1143         .name = driver_name,
1144         .id = -1,
1145         .dev = {
1146                 .release = the_pdev_release,
1147         },
1148 };
1149
1150 static int __init vhci_hcd_init(void)
1151 {
1152         int ret;
1153
1154         if (usb_disabled())
1155                 return -ENODEV;
1156
1157         ret = platform_driver_register(&vhci_driver);
1158         if (ret)
1159                 goto err_driver_register;
1160
1161         ret = platform_device_register(&the_pdev);
1162         if (ret)
1163                 goto err_platform_device_register;
1164
1165         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1166         return ret;
1167
1168 err_platform_device_register:
1169         platform_driver_unregister(&vhci_driver);
1170 err_driver_register:
1171         return ret;
1172 }
1173
1174 static void __exit vhci_hcd_exit(void)
1175 {
1176         platform_device_unregister(&the_pdev);
1177         platform_driver_unregister(&vhci_driver);
1178 }
1179
1180 module_init(vhci_hcd_init);
1181 module_exit(vhci_hcd_exit);
1182
1183 MODULE_AUTHOR(DRIVER_AUTHOR);
1184 MODULE_DESCRIPTION(DRIVER_DESC);
1185 MODULE_LICENSE("GPL");
1186 MODULE_VERSION(USBIP_VERSION);