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         int width;
 224
 225         memset(desc, 0, sizeof(*desc));
 226         desc->bDescriptorType = USB_DT_HUB;
 227         desc->wHubCharacteristics = cpu_to_le16(
 228                 HUB_CHAR_INDV_PORT_LPSM | HUB_CHAR_COMMON_OCPM);
 229
 230         desc->bNbrPorts = VHCI_NPORTS;
 231         BUILD_BUG_ON(VHCI_NPORTS > USB_MAXCHILDREN);
 232         width = desc->bNbrPorts / 8 + 1;
 233         desc->bDescLength = USB_DT_HUB_NONVAR_SIZE + 2 * width;
 234         memset(&desc->u.hs.DeviceRemovable[0], 0, width);
 235         memset(&desc->u.hs.DeviceRemovable[width], 0xff, width);
 236 }
 237
 238 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 239                             u16 wIndex, char *buf, u16 wLength)
 240 {
 241         struct vhci_hcd *dum;
 242         int             retval = 0;
 243         int             rhport;
 244         unsigned long   flags;
 245
 246         u32 prev_port_status[VHCI_NPORTS];
 247
 248         if (!HCD_HW_ACCESSIBLE(hcd))
 249                 return -ETIMEDOUT;
 250
 251         /*
 252          * NOTE:
 253          * wIndex shows the port number and begins from 1.
 254          */
 255         usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 256                           wIndex);
 257         if (wIndex > VHCI_NPORTS)
 258                 pr_err("invalid port number %d\n", wIndex);
 259         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 260
 261         dum = hcd_to_vhci(hcd);
 262
 263         spin_lock_irqsave(&dum->lock, flags);
 264
 265         /* store old status and compare now and old later */
 266         if (usbip_dbg_flag_vhci_rh) {
 267                 memcpy(prev_port_status, dum->port_status,
 268                         sizeof(prev_port_status));
 269         }
 270
 271         switch (typeReq) {
 272         case ClearHubFeature:
 273                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
 274                 break;
 275         case ClearPortFeature:
 276                 switch (wValue) {
 277                 case USB_PORT_FEAT_SUSPEND:
 278                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
 279                                 /* 20msec signaling */
 280                                 dum->resuming = 1;
 281                                 dum->re_timeout =
 282                                         jiffies + msecs_to_jiffies(20);
 283                         }
 284                         break;
 285                 case USB_PORT_FEAT_POWER:
 286                         usbip_dbg_vhci_rh(
 287                                 " ClearPortFeature: USB_PORT_FEAT_POWER\n");
 288                         dum->port_status[rhport] &= ~USB_PORT_STAT_POWER;
 289                         dum->resuming = 0;
 290                         break;
 291                 case USB_PORT_FEAT_C_RESET:
 292                         usbip_dbg_vhci_rh(
 293                                 " ClearPortFeature: USB_PORT_FEAT_C_RESET\n");
 294                         switch (dum->vdev[rhport].speed) {
 295                         case USB_SPEED_HIGH:
 296                                 dum->port_status[rhport] |=
 297                                         USB_PORT_STAT_HIGH_SPEED;
 298                                 break;
 299                         case USB_SPEED_LOW:
 300                                 dum->port_status[rhport] |=
 301                                         USB_PORT_STAT_LOW_SPEED;
 302                                 break;
 303                         default:
 304                                 break;
 305                         }
 306                         break;
 307                 default:
 308                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 309                                           wValue);
 310                         dum->port_status[rhport] &= ~(1 << wValue);
 311                         break;
 312                 }
 313                 break;
 314         case GetHubDescriptor:
 315                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 316                 hub_descriptor((struct usb_hub_descriptor *) buf);
 317                 break;
 318         case GetHubStatus:
 319                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 320                 *(__le32 *) buf = cpu_to_le32(0);
 321                 break;
 322         case GetPortStatus:
 323                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 324                 if (wIndex > VHCI_NPORTS || wIndex < 1) {
 325                         pr_err("invalid port number %d\n", wIndex);
 326                         retval = -EPIPE;
 327                 }
 328
 329                 /* we do not care about resume. */
 330
 331                 /* whoever resets or resumes must GetPortStatus to
 332                  * complete it!!
 333                  */
 334                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 335                         dum->port_status[rhport] |=
 336                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 337                         dum->port_status[rhport] &=
 338                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 339                         dum->resuming = 0;
 340                         dum->re_timeout = 0;
 341                 }
 342
 343                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 344                     0 && time_after(jiffies, dum->re_timeout)) {
 345                         dum->port_status[rhport] |=
 346                                 (1 << USB_PORT_FEAT_C_RESET);
 347                         dum->port_status[rhport] &=
 348                                 ~(1 << USB_PORT_FEAT_RESET);
 349                         dum->re_timeout = 0;
 350
 351                         if (dum->vdev[rhport].ud.status ==
 352                             VDEV_ST_NOTASSIGNED) {
 353                                 usbip_dbg_vhci_rh(
 354                                         " enable rhport %d (status %u)\n",
 355                                         rhport,
 356                                         dum->vdev[rhport].ud.status);
 357                                 dum->port_status[rhport] |=
 358                                         USB_PORT_STAT_ENABLE;
 359                         }
 360                 }
 361                 ((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 362                 ((__le16 *) buf)[1] =
 363                         cpu_to_le16(dum->port_status[rhport] >> 16);
 364
 365                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 366                                   ((u16 *)buf)[1]);
 367                 break;
 368         case SetHubFeature:
 369                 usbip_dbg_vhci_rh(" SetHubFeature\n");
 370                 retval = -EPIPE;
 371                 break;
 372         case SetPortFeature:
 373                 switch (wValue) {
 374                 case USB_PORT_FEAT_SUSPEND:
 375                         usbip_dbg_vhci_rh(
 376                                 " SetPortFeature: USB_PORT_FEAT_SUSPEND\n");
 377                         break;
 378                 case USB_PORT_FEAT_RESET:
 379                         usbip_dbg_vhci_rh(
 380                                 " SetPortFeature: USB_PORT_FEAT_RESET\n");
 381                         /* if it's already running, disconnect first */
 382                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 383                                 dum->port_status[rhport] &=
 384                                         ~(USB_PORT_STAT_ENABLE |
 385                                           USB_PORT_STAT_LOW_SPEED |
 386                                           USB_PORT_STAT_HIGH_SPEED);
 387                                 /* FIXME test that code path! */
 388                         }
 389                         /* 50msec reset signaling */
 390                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
 391
 392                         /* FALLTHROUGH */
 393                 default:
 394                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 395                                           wValue);
 396                         dum->port_status[rhport] |= (1 << wValue);
 397                         break;
 398                 }
 399                 break;
 400
 401         default:
 402                 pr_err("default: no such request\n");
 403
 404                 /* "protocol stall" on error */
 405                 retval = -EPIPE;
 406         }
 407
 408         if (usbip_dbg_flag_vhci_rh) {
 409                 pr_debug("port %d\n", rhport);
 410                 /* Only dump valid port status */
 411                 if (rhport >= 0) {
 412                         dump_port_status_diff(prev_port_status[rhport],
 413                                               dum->port_status[rhport]);
 414                 }
 415         }
 416         usbip_dbg_vhci_rh(" bye\n");
 417
 418         spin_unlock_irqrestore(&dum->lock, flags);
 419
 420         return retval;
 421 }
 422
 423 static struct vhci_device *get_vdev(struct usb_device *udev)
 424 {
 425         int i;
 426
 427         if (!udev)
 428                 return NULL;
 429
 430         for (i = 0; i < VHCI_NPORTS; i++)
 431                 if (the_controller->vdev[i].udev == udev)
 432                         return port_to_vdev(i);
 433
 434         return NULL;
 435 }
 436
 437 static void vhci_tx_urb(struct urb *urb)
 438 {
 439         struct vhci_device *vdev = get_vdev(urb->dev);
 440         struct vhci_priv *priv;
 441         unsigned long flags;
 442
 443         if (!vdev) {
 444                 pr_err("could not get virtual device");
 445                 return;
 446         }
 447
 448         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 449         if (!priv) {
 450                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 451                 return;
 452         }
 453
 454         spin_lock_irqsave(&vdev->priv_lock, flags);
 455
 456         priv->seqnum = atomic_inc_return(&the_controller->seqnum);
 457         if (priv->seqnum == 0xffff)
 458                 dev_info(&urb->dev->dev, "seqnum max\n");
 459
 460         priv->vdev = vdev;
 461         priv->urb = urb;
 462
 463         urb->hcpriv = (void *) priv;
 464
 465         list_add_tail(&priv->list, &vdev->priv_tx);
 466
 467         wake_up(&vdev->waitq_tx);
 468         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 469 }
 470
 471 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 472                             gfp_t mem_flags)
 473 {
 474         struct device *dev = &urb->dev->dev;
 475         int ret = 0;
 476         struct vhci_device *vdev;
 477         unsigned long 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                         usb_put_dev(vdev->udev);
 534                         vdev->udev = usb_get_dev(urb->dev);
 535
 536                         spin_lock(&vdev->ud.lock);
 537                         vdev->ud.status = VDEV_ST_USED;
 538                         spin_unlock(&vdev->ud.lock);
 539
 540                         if (urb->status == -EINPROGRESS) {
 541                                 /* This request is successfully completed. */
 542                                 /* If not -EINPROGRESS, possibly unlinked. */
 543                                 urb->status = 0;
 544                         }
 545
 546                         goto no_need_xmit;
 547
 548                 case USB_REQ_GET_DESCRIPTOR:
 549                         if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
 550                                 usbip_dbg_vhci_hc(
 551                                         "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
 552
 553                         usb_put_dev(vdev->udev);
 554                         vdev->udev = usb_get_dev(urb->dev);
 555                         goto out;
 556
 557                 default:
 558                         /* NOT REACHED */
 559                         dev_err(dev,
 560                                 "invalid request to devnum 0 bRequest %u, wValue %u\n",
 561                                 ctrlreq->bRequest,
 562                                 ctrlreq->wValue);
 563                         ret =  -EINVAL;
 564                         goto no_need_xmit;
 565                 }
 566
 567         }
 568
 569 out:
 570         vhci_tx_urb(urb);
 571         spin_unlock_irqrestore(&the_controller->lock, flags);
 572
 573         return 0;
 574
 575 no_need_xmit:
 576         usb_hcd_unlink_urb_from_ep(hcd, urb);
 577 no_need_unlink:
 578         spin_unlock_irqrestore(&the_controller->lock, flags);
 579         if (!ret)
 580                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller),
 581                                      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         struct vhci_priv *priv;
 634         struct vhci_device *vdev;
 635         unsigned long flags;
 636
 637         spin_lock_irqsave(&the_controller->lock, flags);
 638
 639         priv = urb->hcpriv;
 640         if (!priv) {
 641                 /* URB was never linked! or will be soon given back by
 642                  * vhci_rx. */
 643                 spin_unlock_irqrestore(&the_controller->lock, flags);
 644                 return -EIDRM;
 645         }
 646
 647         {
 648                 int ret = 0;
 649
 650                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 651                 if (ret) {
 652                         spin_unlock_irqrestore(&the_controller->lock, flags);
 653                         return ret;
 654                 }
 655         }
 656
 657          /* send unlink request here? */
 658         vdev = priv->vdev;
 659
 660         if (!vdev->ud.tcp_socket) {
 661                 /* tcp connection is closed */
 662                 spin_lock(&vdev->priv_lock);
 663
 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                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 676
 677                 spin_unlock_irqrestore(&the_controller->lock, flags);
 678                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 679                                      urb->status);
 680                 spin_lock_irqsave(&the_controller->lock, flags);
 681
 682         } else {
 683                 /* tcp connection is alive */
 684                 struct vhci_unlink *unlink;
 685
 686                 spin_lock(&vdev->priv_lock);
 687
 688                 /* setup CMD_UNLINK pdu */
 689                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 690                 if (!unlink) {
 691                         spin_unlock(&vdev->priv_lock);
 692                         spin_unlock_irqrestore(&the_controller->lock, flags);
 693                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 694                         return -ENOMEM;
 695                 }
 696
 697                 unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
 698                 if (unlink->seqnum == 0xffff)
 699                         pr_info("seqnum max\n");
 700
 701                 unlink->unlink_seqnum = priv->seqnum;
 702
 703                 /* send cmd_unlink and try to cancel the pending URB in the
 704                  * peer */
 705                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 706                 wake_up(&vdev->waitq_tx);
 707
 708                 spin_unlock(&vdev->priv_lock);
 709         }
 710
 711         spin_unlock_irqrestore(&the_controller->lock, flags);
 712
 713         usbip_dbg_vhci_hc("leave\n");
 714         return 0;
 715 }
 716
 717 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 718 {
 719         struct vhci_unlink *unlink, *tmp;
 720         unsigned long flags;
 721
 722         spin_lock_irqsave(&the_controller->lock, flags);
 723         spin_lock(&vdev->priv_lock);
 724
 725         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 726                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 727                 list_del(&unlink->list);
 728                 kfree(unlink);
 729         }
 730
 731         while (!list_empty(&vdev->unlink_rx)) {
 732                 struct urb *urb;
 733
 734                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 735                         list);
 736
 737                 /* give back URB of unanswered unlink request */
 738                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 739
 740                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 741                 if (!urb) {
 742                         pr_info("the urb (seqnum %lu) was already given back\n",
 743                                 unlink->unlink_seqnum);
 744                         list_del(&unlink->list);
 745                         kfree(unlink);
 746                         continue;
 747                 }
 748
 749                 urb->status = -ENODEV;
 750
 751                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 752
 753                 list_del(&unlink->list);
 754
 755                 spin_unlock(&vdev->priv_lock);
 756                 spin_unlock_irqrestore(&the_controller->lock, flags);
 757
 758                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 759                                      urb->status);
 760
 761                 spin_lock_irqsave(&the_controller->lock, flags);
 762                 spin_lock(&vdev->priv_lock);
 763
 764                 kfree(unlink);
 765         }
 766
 767         spin_unlock(&vdev->priv_lock);
 768         spin_unlock_irqrestore(&the_controller->lock, flags);
 769 }
 770
 771 /*
 772  * The important thing is that only one context begins cleanup.
 773  * This is why error handling and cleanup become simple.
 774  * We do not want to consider race condition as possible.
 775  */
 776 static void vhci_shutdown_connection(struct usbip_device *ud)
 777 {
 778         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 779
 780         /* need this? see stub_dev.c */
 781         if (ud->tcp_socket) {
 782                 pr_debug("shutdown sockfd %d\n", ud->sockfd);
 783                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 784         }
 785
 786         /* kill threads related to this sdev */
 787         if (vdev->ud.tcp_rx) {
 788                 kthread_stop_put(vdev->ud.tcp_rx);
 789                 vdev->ud.tcp_rx = NULL;
 790         }
 791         if (vdev->ud.tcp_tx) {
 792                 kthread_stop_put(vdev->ud.tcp_tx);
 793                 vdev->ud.tcp_tx = NULL;
 794         }
 795         pr_info("stop threads\n");
 796
 797         /* active connection is closed */
 798         if (vdev->ud.tcp_socket) {
 799                 sockfd_put(vdev->ud.tcp_socket);
 800                 vdev->ud.tcp_socket = NULL;
 801                 vdev->ud.sockfd = -1;
 802         }
 803         pr_info("release socket\n");
 804
 805         vhci_device_unlink_cleanup(vdev);
 806
 807         /*
 808          * rh_port_disconnect() is a trigger of ...
 809          *   usb_disable_device():
 810          *      disable all the endpoints for a USB device.
 811          *   usb_disable_endpoint():
 812          *      disable endpoints. pending urbs are unlinked(dequeued).
 813          *
 814          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 815          * detached device should release used urbs in a cleanup function (i.e.
 816          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 817          * pushed urbs and their private data in this function.
 818          *
 819          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 820          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 821          * gives back pushed urbs and frees their private data by request of
 822          * the cleanup function of a USB driver. When unlinking a urb with an
 823          * active connection, vhci_dequeue() does not give back the urb which
 824          * is actually given back by vhci_rx after receiving its return pdu.
 825          *
 826          */
 827         rh_port_disconnect(vdev->rhport);
 828
 829         pr_info("disconnect device\n");
 830 }
 831
 832
 833 static void vhci_device_reset(struct usbip_device *ud)
 834 {
 835         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 836         unsigned long flags;
 837
 838         spin_lock_irqsave(&ud->lock, flags);
 839
 840         vdev->speed  = 0;
 841         vdev->devid  = 0;
 842
 843         usb_put_dev(vdev->udev);
 844         vdev->udev = NULL;
 845
 846         if (ud->tcp_socket) {
 847                 sockfd_put(ud->tcp_socket);
 848                 ud->tcp_socket = NULL;
 849                 ud->sockfd = -1;
 850         }
 851         ud->status = VDEV_ST_NULL;
 852
 853         spin_unlock_irqrestore(&ud->lock, flags);
 854 }
 855
 856 static void vhci_device_unusable(struct usbip_device *ud)
 857 {
 858         unsigned long flags;
 859
 860         spin_lock_irqsave(&ud->lock, flags);
 861         ud->status = VDEV_ST_ERROR;
 862         spin_unlock_irqrestore(&ud->lock, flags);
 863 }
 864
 865 static void vhci_device_init(struct vhci_device *vdev)
 866 {
 867         memset(vdev, 0, sizeof(*vdev));
 868
 869         vdev->ud.side   = USBIP_VHCI;
 870         vdev->ud.status = VDEV_ST_NULL;
 871         spin_lock_init(&vdev->ud.lock);
 872
 873         INIT_LIST_HEAD(&vdev->priv_rx);
 874         INIT_LIST_HEAD(&vdev->priv_tx);
 875         INIT_LIST_HEAD(&vdev->unlink_tx);
 876         INIT_LIST_HEAD(&vdev->unlink_rx);
 877         spin_lock_init(&vdev->priv_lock);
 878
 879         init_waitqueue_head(&vdev->waitq_tx);
 880
 881         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 882         vdev->ud.eh_ops.reset = vhci_device_reset;
 883         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 884
 885         usbip_start_eh(&vdev->ud);
 886 }
 887
 888 static int vhci_start(struct usb_hcd *hcd)
 889 {
 890         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 891         int rhport;
 892         int err = 0;
 893
 894         usbip_dbg_vhci_hc("enter vhci_start\n");
 895
 896         /* initialize private data of usb_hcd */
 897
 898         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 899                 struct vhci_device *vdev = &vhci->vdev[rhport];
 900
 901                 vhci_device_init(vdev);
 902                 vdev->rhport = rhport;
 903         }
 904
 905         atomic_set(&vhci->seqnum, 0);
 906         spin_lock_init(&vhci->lock);
 907
 908         hcd->power_budget = 0; /* no limit */
 909         hcd->uses_new_polling = 1;
 910
 911         /* vhci_hcd is now ready to be controlled through sysfs */
 912         err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 913         if (err) {
 914                 pr_err("create sysfs files\n");
 915                 return err;
 916         }
 917
 918         return 0;
 919 }
 920
 921 static void vhci_stop(struct usb_hcd *hcd)
 922 {
 923         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 924         int rhport = 0;
 925
 926         usbip_dbg_vhci_hc("stop VHCI controller\n");
 927
 928         /* 1. remove the userland interface of vhci_hcd */
 929         sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 930
 931         /* 2. shutdown all the ports of vhci_hcd */
 932         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 933                 struct vhci_device *vdev = &vhci->vdev[rhport];
 934
 935                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
 936                 usbip_stop_eh(&vdev->ud);
 937         }
 938 }
 939
 940 static int vhci_get_frame_number(struct usb_hcd *hcd)
 941 {
 942         pr_err("Not yet implemented\n");
 943         return 0;
 944 }
 945
 946 #ifdef CONFIG_PM
 947
 948 /* FIXME: suspend/resume */
 949 static int vhci_bus_suspend(struct usb_hcd *hcd)
 950 {
 951         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 952         unsigned long flags;
 953
 954         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 955
 956         spin_lock_irqsave(&vhci->lock, flags);
 957         hcd->state = HC_STATE_SUSPENDED;
 958         spin_unlock_irqrestore(&vhci->lock, flags);
 959
 960         return 0;
 961 }
 962
 963 static int vhci_bus_resume(struct usb_hcd *hcd)
 964 {
 965         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 966         int rc = 0;
 967         unsigned long flags;
 968
 969         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 970
 971         spin_lock_irqsave(&vhci->lock, flags);
 972         if (!HCD_HW_ACCESSIBLE(hcd))
 973                 rc = -ESHUTDOWN;
 974         else
 975                 hcd->state = HC_STATE_RUNNING;
 976         spin_unlock_irqrestore(&vhci->lock, flags);
 977
 978         return rc;
 979 }
 980
 981 #else
 982
 983 #define vhci_bus_suspend      NULL
 984 #define vhci_bus_resume       NULL
 985 #endif
 986
 987 static struct hc_driver vhci_hc_driver = {
 988         .description    = driver_name,
 989         .product_desc   = driver_desc,
 990         .hcd_priv_size  = sizeof(struct vhci_hcd),
 991
 992         .flags          = HCD_USB2,
 993
 994         .start          = vhci_start,
 995         .stop           = vhci_stop,
 996
 997         .urb_enqueue    = vhci_urb_enqueue,
 998         .urb_dequeue    = vhci_urb_dequeue,
 999
1000         .get_frame_number = vhci_get_frame_number,
1001
1002         .hub_status_data = vhci_hub_status,
1003         .hub_control    = vhci_hub_control,
1004         .bus_suspend    = vhci_bus_suspend,
1005         .bus_resume     = vhci_bus_resume,
1006 };
1007
1008 static int vhci_hcd_probe(struct platform_device *pdev)
1009 {
1010         struct usb_hcd          *hcd;
1011         int                     ret;
1012
1013         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1014
1015         /*
1016          * Allocate and initialize hcd.
1017          * Our private data is also allocated automatically.
1018          */
1019         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1020         if (!hcd) {
1021                 pr_err("create hcd failed\n");
1022                 return -ENOMEM;
1023         }
1024         hcd->has_tt = 1;
1025
1026         /* this is private data for vhci_hcd */
1027         the_controller = hcd_to_vhci(hcd);
1028
1029         /*
1030          * Finish generic HCD structure initialization and register.
1031          * Call the driver's reset() and start() routines.
1032          */
1033         ret = usb_add_hcd(hcd, 0, 0);
1034         if (ret != 0) {
1035                 pr_err("usb_add_hcd failed %d\n", ret);
1036                 usb_put_hcd(hcd);
1037                 the_controller = NULL;
1038                 return ret;
1039         }
1040
1041         usbip_dbg_vhci_hc("bye\n");
1042         return 0;
1043 }
1044
1045 static int vhci_hcd_remove(struct platform_device *pdev)
1046 {
1047         struct usb_hcd  *hcd;
1048
1049         hcd = platform_get_drvdata(pdev);
1050         if (!hcd)
1051                 return 0;
1052
1053         /*
1054          * Disconnects the root hub,
1055          * then reverses the effects of usb_add_hcd(),
1056          * invoking the HCD's stop() methods.
1057          */
1058         usb_remove_hcd(hcd);
1059         usb_put_hcd(hcd);
1060         the_controller = NULL;
1061
1062         return 0;
1063 }
1064
1065 #ifdef CONFIG_PM
1066
1067 /* what should happen for USB/IP under suspend/resume? */
1068 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1069 {
1070         struct usb_hcd *hcd;
1071         int rhport = 0;
1072         int connected = 0;
1073         int ret = 0;
1074         unsigned long flags;
1075
1076         hcd = platform_get_drvdata(pdev);
1077
1078         spin_lock_irqsave(&the_controller->lock, flags);
1079
1080         for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1081                 if (the_controller->port_status[rhport] &
1082                     USB_PORT_STAT_CONNECTION)
1083                         connected += 1;
1084
1085         spin_unlock_irqrestore(&the_controller->lock, flags);
1086
1087         if (connected > 0) {
1088                 dev_info(&pdev->dev,
1089                          "We have %d active connection%s. Do not suspend.\n",
1090                          connected, (connected == 1 ? "" : "s"));
1091                 ret =  -EBUSY;
1092         } else {
1093                 dev_info(&pdev->dev, "suspend vhci_hcd");
1094                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1095         }
1096
1097         return ret;
1098 }
1099
1100 static int vhci_hcd_resume(struct platform_device *pdev)
1101 {
1102         struct usb_hcd *hcd;
1103
1104         dev_dbg(&pdev->dev, "%s\n", __func__);
1105
1106         hcd = platform_get_drvdata(pdev);
1107         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1108         usb_hcd_poll_rh_status(hcd);
1109
1110         return 0;
1111 }
1112
1113 #else
1114
1115 #define vhci_hcd_suspend        NULL
1116 #define vhci_hcd_resume         NULL
1117
1118 #endif
1119
1120 static struct platform_driver vhci_driver = {
1121         .probe  = vhci_hcd_probe,
1122         .remove = vhci_hcd_remove,
1123         .suspend = vhci_hcd_suspend,
1124         .resume = vhci_hcd_resume,
1125         .driver = {
1126                 .name = driver_name,
1127         },
1128 };
1129
1130 /*
1131  * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1132  * We need to add this virtual device as a platform device arbitrarily:
1133  *      1. platform_device_register()
1134  */
1135 static void the_pdev_release(struct device *dev)
1136 {
1137 }
1138
1139 static struct platform_device the_pdev = {
1140         /* should be the same name as driver_name */
1141         .name = driver_name,
1142         .id = -1,
1143         .dev = {
1144                 .release = the_pdev_release,
1145         },
1146 };
1147
1148 static int __init vhci_hcd_init(void)
1149 {
1150         int ret;
1151
1152         if (usb_disabled())
1153                 return -ENODEV;
1154
1155         ret = platform_driver_register(&vhci_driver);
1156         if (ret)
1157                 goto err_driver_register;
1158
1159         ret = platform_device_register(&the_pdev);
1160         if (ret)
1161                 goto err_platform_device_register;
1162
1163         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1164         return ret;
1165
1166 err_platform_device_register:
1167         platform_driver_unregister(&vhci_driver);
1168 err_driver_register:
1169         return ret;
1170 }
1171
1172 static void __exit vhci_hcd_exit(void)
1173 {
1174         platform_device_unregister(&the_pdev);
1175         platform_driver_unregister(&vhci_driver);
1176 }
1177
1178 module_init(vhci_hcd_init);
1179 module_exit(vhci_hcd_exit);
1180
1181 MODULE_AUTHOR(DRIVER_AUTHOR);
1182 MODULE_DESCRIPTION(DRIVER_DESC);
1183 MODULE_LICENSE("GPL");
1184 MODULE_VERSION(USBIP_VERSION);