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