drivers/usb/usbip/vhci_hcd.c

   1 /*
   2  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   3  * Copyright (C) 2015-2016 Nobuo Iwata
   4  *
   5  * This is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  18  * USA.
  19  */
  20
  21 #include <linux/init.h>
  22 #include <linux/file.h>
  23 #include <linux/kernel.h>
  24 #include <linux/kthread.h>
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/slab.h>
  28
  29 #include "usbip_common.h"
  30 #include "vhci.h"
  31
  32 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
  33 #define DRIVER_DESC "USB/IP 'Virtual' Host Controller (VHCI) Driver"
  34
  35 /*
  36  * TODO
  37  *      - update root hub emulation
  38  *      - move the emulation code to userland ?
  39  *              porting to other operating systems
  40  *              minimize kernel code
  41  *      - add suspend/resume code
  42  *      - clean up everything
  43  */
  44
  45 /* See usb gadget dummy hcd */
  46
  47 static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
  48 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
  49                             u16 wIndex, char *buff, u16 wLength);
  50 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
  51                             gfp_t mem_flags);
  52 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
  53 static int vhci_start(struct usb_hcd *vhci_hcd);
  54 static void vhci_stop(struct usb_hcd *hcd);
  55 static int vhci_get_frame_number(struct usb_hcd *hcd);
  56
  57 static const char driver_name[] = "vhci_hcd";
  58 static const char driver_desc[] = "USB/IP Virtual Host Controller";
  59
  60 int vhci_num_controllers = VHCI_NR_HCS;
  61
  62 struct platform_device **vhci_pdevs;
  63
  64 static const char * const bit_desc[] = {
  65         "CONNECTION",           /*0*/
  66         "ENABLE",               /*1*/
  67         "SUSPEND",              /*2*/
  68         "OVER_CURRENT",         /*3*/
  69         "RESET",                /*4*/
  70         "R5",                   /*5*/
  71         "R6",                   /*6*/
  72         "R7",                   /*7*/
  73         "POWER",                /*8*/
  74         "LOWSPEED",             /*9*/
  75         "HIGHSPEED",            /*10*/
  76         "PORT_TEST",            /*11*/
  77         "INDICATOR",            /*12*/
  78         "R13",                  /*13*/
  79         "R14",                  /*14*/
  80         "R15",                  /*15*/
  81         "C_CONNECTION",         /*16*/
  82         "C_ENABLE",             /*17*/
  83         "C_SUSPEND",            /*18*/
  84         "C_OVER_CURRENT",       /*19*/
  85         "C_RESET",              /*20*/
  86         "R21",                  /*21*/
  87         "R22",                  /*22*/
  88         "R23",                  /*23*/
  89         "R24",                  /*24*/
  90         "R25",                  /*25*/
  91         "R26",                  /*26*/
  92         "R27",                  /*27*/
  93         "R28",                  /*28*/
  94         "R29",                  /*29*/
  95         "R30",                  /*30*/
  96         "R31",                  /*31*/
  97 };
  98
  99 static void dump_port_status_diff(u32 prev_status, u32 new_status)
 100 {
 101         int i = 0;
 102         u32 bit = 1;
 103
 104         pr_debug("status prev -> new: %08x -> %08x\n", prev_status, new_status);
 105         while (bit) {
 106                 u32 prev = prev_status & bit;
 107                 u32 new = new_status & bit;
 108                 char change;
 109
 110                 if (!prev && new)
 111                         change = '+';
 112                 else if (prev && !new)
 113                         change = '-';
 114                 else
 115                         change = ' ';
 116
 117                 if (prev || new)
 118                         pr_debug(" %c%s\n", change, bit_desc[i]);
 119                 bit <<= 1;
 120                 i++;
 121         }
 122         pr_debug("\n");
 123 }
 124
 125 void rh_port_connect(struct vhci_device *vdev, enum usb_device_speed speed)
 126 {
 127         struct vhci_hcd *vhci = vdev_to_vhci(vdev);
 128         int             rhport = vdev->rhport;
 129         u32             status;
 130         unsigned long   flags;
 131
 132         usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
 133
 134         spin_lock_irqsave(&vhci->lock, flags);
 135
 136         status = vhci->port_status[rhport];
 137
 138         status |= USB_PORT_STAT_CONNECTION | (1 << USB_PORT_FEAT_C_CONNECTION);
 139
 140         switch (speed) {
 141         case USB_SPEED_HIGH:
 142                 status |= USB_PORT_STAT_HIGH_SPEED;
 143                 break;
 144         case USB_SPEED_LOW:
 145                 status |= USB_PORT_STAT_LOW_SPEED;
 146                 break;
 147         default:
 148                 break;
 149         }
 150
 151         vhci->port_status[rhport] = status;
 152
 153         spin_unlock_irqrestore(&vhci->lock, flags);
 154
 155         usb_hcd_poll_rh_status(vhci_to_hcd(vhci));
 156 }
 157
 158 static void rh_port_disconnect(struct vhci_device *vdev)
 159 {
 160         struct vhci_hcd *vhci = vdev_to_vhci(vdev);
 161         int             rhport = vdev->rhport;
 162         u32             status;
 163         unsigned long   flags;
 164
 165         usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
 166
 167         spin_lock_irqsave(&vhci->lock, flags);
 168
 169         status = vhci->port_status[rhport];
 170
 171         status &= ~USB_PORT_STAT_CONNECTION;
 172         status |= (1 << USB_PORT_FEAT_C_CONNECTION);
 173
 174         vhci->port_status[rhport] = status;
 175
 176         spin_unlock_irqrestore(&vhci->lock, flags);
 177         usb_hcd_poll_rh_status(vhci_to_hcd(vhci));
 178 }
 179
 180 #define PORT_C_MASK                             \
 181         ((USB_PORT_STAT_C_CONNECTION            \
 182           | USB_PORT_STAT_C_ENABLE              \
 183           | USB_PORT_STAT_C_SUSPEND             \
 184           | USB_PORT_STAT_C_OVERCURRENT         \
 185           | USB_PORT_STAT_C_RESET) << 16)
 186
 187 /*
 188  * Returns 0 if the status hasn't changed, or the number of bytes in buf.
 189  * Ports are 0-indexed from the HCD point of view,
 190  * and 1-indexed from the USB core pointer of view.
 191  *
 192  * @buf: a bitmap to show which port status has been changed.
 193  *  bit  0: reserved
 194  *  bit  1: the status of port 0 has been changed.
 195  *  bit  2: the status of port 1 has been changed.
 196  *  ...
 197  */
 198 static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
 199 {
 200         struct vhci_hcd *vhci;
 201         int             retval;
 202         int             rhport;
 203         int             changed = 0;
 204         unsigned long   flags;
 205
 206         retval = DIV_ROUND_UP(VHCI_HC_PORTS + 1, 8);
 207         memset(buf, 0, retval);
 208
 209         vhci = hcd_to_vhci(hcd);
 210
 211         spin_lock_irqsave(&vhci->lock, flags);
 212         if (!HCD_HW_ACCESSIBLE(hcd)) {
 213                 usbip_dbg_vhci_rh("hw accessible flag not on?\n");
 214                 goto done;
 215         }
 216
 217         /* check pseudo status register for each port */
 218         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 219                 if ((vhci->port_status[rhport] & PORT_C_MASK)) {
 220                         /* The status of a port has been changed, */
 221                         usbip_dbg_vhci_rh("port %d status changed\n", rhport);
 222
 223                         buf[(rhport + 1) / 8] |= 1 << (rhport + 1) % 8;
 224                         changed = 1;
 225                 }
 226         }
 227
 228         if ((hcd->state == HC_STATE_SUSPENDED) && (changed == 1))
 229                 usb_hcd_resume_root_hub(hcd);
 230
 231 done:
 232         spin_unlock_irqrestore(&vhci->lock, flags);
 233         return changed ? retval : 0;
 234 }
 235
 236 static inline void hub_descriptor(struct usb_hub_descriptor *desc)
 237 {
 238         memset(desc, 0, sizeof(*desc));
 239         desc->bDescriptorType = USB_DT_HUB;
 240         desc->bDescLength = 9;
 241         desc->wHubCharacteristics = cpu_to_le16(
 242                 HUB_CHAR_INDV_PORT_LPSM | HUB_CHAR_COMMON_OCPM);
 243         desc->bNbrPorts = VHCI_HC_PORTS;
 244         desc->u.hs.DeviceRemovable[0] = 0xff;
 245         desc->u.hs.DeviceRemovable[1] = 0xff;
 246 }
 247
 248 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 249                             u16 wIndex, char *buf, u16 wLength)
 250 {
 251         struct vhci_hcd *dum;
 252         int             retval = 0;
 253         int             rhport;
 254         unsigned long   flags;
 255
 256         u32 prev_port_status[VHCI_HC_PORTS];
 257
 258         if (!HCD_HW_ACCESSIBLE(hcd))
 259                 return -ETIMEDOUT;
 260
 261         /*
 262          * NOTE:
 263          * wIndex shows the port number and begins from 1.
 264          */
 265         usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 266                           wIndex);
 267         if (wIndex > VHCI_HC_PORTS)
 268                 pr_err("invalid port number %d\n", wIndex);
 269         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 270
 271         dum = hcd_to_vhci(hcd);
 272
 273         spin_lock_irqsave(&dum->lock, flags);
 274
 275         /* store old status and compare now and old later */
 276         if (usbip_dbg_flag_vhci_rh) {
 277                 memcpy(prev_port_status, dum->port_status,
 278                         sizeof(prev_port_status));
 279         }
 280
 281         switch (typeReq) {
 282         case ClearHubFeature:
 283                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
 284                 break;
 285         case ClearPortFeature:
 286                 switch (wValue) {
 287                 case USB_PORT_FEAT_SUSPEND:
 288                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
 289                                 /* 20msec signaling */
 290                                 dum->resuming = 1;
 291                                 dum->re_timeout =
 292                                         jiffies + msecs_to_jiffies(20);
 293                         }
 294                         break;
 295                 case USB_PORT_FEAT_POWER:
 296                         usbip_dbg_vhci_rh(
 297                                 " ClearPortFeature: USB_PORT_FEAT_POWER\n");
 298                         dum->port_status[rhport] = 0;
 299                         dum->resuming = 0;
 300                         break;
 301                 case USB_PORT_FEAT_C_RESET:
 302                         usbip_dbg_vhci_rh(
 303                                 " ClearPortFeature: USB_PORT_FEAT_C_RESET\n");
 304                         switch (dum->vdev[rhport].speed) {
 305                         case USB_SPEED_HIGH:
 306                                 dum->port_status[rhport] |=
 307                                         USB_PORT_STAT_HIGH_SPEED;
 308                                 break;
 309                         case USB_SPEED_LOW:
 310                                 dum->port_status[rhport] |=
 311                                         USB_PORT_STAT_LOW_SPEED;
 312                                 break;
 313                         default:
 314                                 break;
 315                         }
 316                 default:
 317                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 318                                           wValue);
 319                         dum->port_status[rhport] &= ~(1 << wValue);
 320                         break;
 321                 }
 322                 break;
 323         case GetHubDescriptor:
 324                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 325                 hub_descriptor((struct usb_hub_descriptor *) buf);
 326                 break;
 327         case GetHubStatus:
 328                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 329                 *(__le32 *) buf = cpu_to_le32(0);
 330                 break;
 331         case GetPortStatus:
 332                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 333                 if (wIndex > VHCI_HC_PORTS || wIndex < 1) {
 334                         pr_err("invalid port number %d\n", wIndex);
 335                         retval = -EPIPE;
 336                 }
 337
 338                 /* we do not care about resume. */
 339
 340                 /* whoever resets or resumes must GetPortStatus to
 341                  * complete it!!
 342                  */
 343                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 344                         dum->port_status[rhport] |=
 345                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 346                         dum->port_status[rhport] &=
 347                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 348                         dum->resuming = 0;
 349                         dum->re_timeout = 0;
 350                 }
 351
 352                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 353                     0 && time_after(jiffies, dum->re_timeout)) {
 354                         dum->port_status[rhport] |=
 355                                 (1 << USB_PORT_FEAT_C_RESET);
 356                         dum->port_status[rhport] &=
 357                                 ~(1 << USB_PORT_FEAT_RESET);
 358                         dum->re_timeout = 0;
 359
 360                         if (dum->vdev[rhport].ud.status ==
 361                             VDEV_ST_NOTASSIGNED) {
 362                                 usbip_dbg_vhci_rh(
 363                                         " enable rhport %d (status %u)\n",
 364                                         rhport,
 365                                         dum->vdev[rhport].ud.status);
 366                                 dum->port_status[rhport] |=
 367                                         USB_PORT_STAT_ENABLE;
 368                         }
 369                 }
 370                 ((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 371                 ((__le16 *) buf)[1] =
 372                         cpu_to_le16(dum->port_status[rhport] >> 16);
 373
 374                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 375                                   ((u16 *)buf)[1]);
 376                 break;
 377         case SetHubFeature:
 378                 usbip_dbg_vhci_rh(" SetHubFeature\n");
 379                 retval = -EPIPE;
 380                 break;
 381         case SetPortFeature:
 382                 switch (wValue) {
 383                 case USB_PORT_FEAT_SUSPEND:
 384                         usbip_dbg_vhci_rh(
 385                                 " SetPortFeature: USB_PORT_FEAT_SUSPEND\n");
 386                         break;
 387                 case USB_PORT_FEAT_RESET:
 388                         usbip_dbg_vhci_rh(
 389                                 " SetPortFeature: USB_PORT_FEAT_RESET\n");
 390                         /* if it's already running, disconnect first */
 391                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 392                                 dum->port_status[rhport] &=
 393                                         ~(USB_PORT_STAT_ENABLE |
 394                                           USB_PORT_STAT_LOW_SPEED |
 395                                           USB_PORT_STAT_HIGH_SPEED);
 396                                 /* FIXME test that code path! */
 397                         }
 398                         /* 50msec reset signaling */
 399                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
 400
 401                         /* FALLTHROUGH */
 402                 default:
 403                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 404                                           wValue);
 405                         dum->port_status[rhport] |= (1 << wValue);
 406                         break;
 407                 }
 408                 break;
 409
 410         default:
 411                 pr_err("default: no such request\n");
 412
 413                 /* "protocol stall" on error */
 414                 retval = -EPIPE;
 415         }
 416
 417         if (usbip_dbg_flag_vhci_rh) {
 418                 pr_debug("port %d\n", rhport);
 419                 /* Only dump valid port status */
 420                 if (rhport >= 0) {
 421                         dump_port_status_diff(prev_port_status[rhport],
 422                                               dum->port_status[rhport]);
 423                 }
 424         }
 425         usbip_dbg_vhci_rh(" bye\n");
 426
 427         spin_unlock_irqrestore(&dum->lock, flags);
 428
 429         return retval;
 430 }
 431
 432 static struct vhci_device *get_vdev(struct usb_device *udev)
 433 {
 434         struct platform_device *pdev;
 435         struct usb_hcd *hcd;
 436         struct vhci_hcd *vhci;
 437         int pdev_nr, rhport;
 438
 439         if (!udev)
 440                 return NULL;
 441
 442         for (pdev_nr = 0; pdev_nr < vhci_num_controllers; pdev_nr++) {
 443                 pdev = *(vhci_pdevs + pdev_nr);
 444                 if (pdev == NULL)
 445                         continue;
 446                 hcd = platform_get_drvdata(pdev);
 447                 if (hcd == NULL)
 448                         continue;
 449                 vhci = hcd_to_vhci(hcd);
 450                 for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 451                         if (vhci->vdev[rhport].udev == udev)
 452                                 return &vhci->vdev[rhport];
 453                 }
 454         }
 455
 456         return NULL;
 457 }
 458
 459 static void vhci_tx_urb(struct urb *urb)
 460 {
 461         struct vhci_device *vdev = get_vdev(urb->dev);
 462         struct vhci_priv *priv;
 463         struct vhci_hcd *vhci;
 464         unsigned long flags;
 465
 466         if (!vdev) {
 467                 pr_err("could not get virtual device");
 468                 return;
 469         }
 470         vhci = vdev_to_vhci(vdev);
 471
 472         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 473         if (!priv) {
 474                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 475                 return;
 476         }
 477
 478         spin_lock_irqsave(&vdev->priv_lock, flags);
 479
 480         priv->seqnum = atomic_inc_return(&vhci->seqnum);
 481         if (priv->seqnum == 0xffff)
 482                 dev_info(&urb->dev->dev, "seqnum max\n");
 483
 484         priv->vdev = vdev;
 485         priv->urb = urb;
 486
 487         urb->hcpriv = (void *) priv;
 488
 489         list_add_tail(&priv->list, &vdev->priv_tx);
 490
 491         wake_up(&vdev->waitq_tx);
 492         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 493 }
 494
 495 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 496                             gfp_t mem_flags)
 497 {
 498         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 499         struct device *dev = &urb->dev->dev;
 500         u8 portnum = urb->dev->portnum;
 501         int ret = 0;
 502         struct vhci_device *vdev;
 503         unsigned long flags;
 504
 505         usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
 506                           hcd, urb, mem_flags);
 507
 508         if (portnum > VHCI_HC_PORTS) {
 509                 pr_err("invalid port number %d\n", portnum);
 510                 return -ENODEV;
 511         }
 512         vdev = &vhci->vdev[portnum-1];
 513
 514         /* patch to usb_sg_init() is in 2.5.60 */
 515         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 516
 517         spin_lock_irqsave(&vhci->lock, flags);
 518
 519         if (urb->status != -EINPROGRESS) {
 520                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 521                 spin_unlock_irqrestore(&vhci->lock, flags);
 522                 return urb->status;
 523         }
 524
 525         /* refuse enqueue for dead connection */
 526         spin_lock(&vdev->ud.lock);
 527         if (vdev->ud.status == VDEV_ST_NULL ||
 528             vdev->ud.status == VDEV_ST_ERROR) {
 529                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 530                 spin_unlock(&vdev->ud.lock);
 531                 spin_unlock_irqrestore(&vhci->lock, flags);
 532                 return -ENODEV;
 533         }
 534         spin_unlock(&vdev->ud.lock);
 535
 536         ret = usb_hcd_link_urb_to_ep(hcd, urb);
 537         if (ret)
 538                 goto no_need_unlink;
 539
 540         /*
 541          * The enumeration process is as follows;
 542          *
 543          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 544          *     to get max packet length of default pipe
 545          *
 546          *  2. Set_Address request to DevAddr(0) EndPoint(0)
 547          *
 548          */
 549         if (usb_pipedevice(urb->pipe) == 0) {
 550                 __u8 type = usb_pipetype(urb->pipe);
 551                 struct usb_ctrlrequest *ctrlreq =
 552                         (struct usb_ctrlrequest *) urb->setup_packet;
 553
 554                 if (type != PIPE_CONTROL || !ctrlreq) {
 555                         dev_err(dev, "invalid request to devnum 0\n");
 556                         ret = -EINVAL;
 557                         goto no_need_xmit;
 558                 }
 559
 560                 switch (ctrlreq->bRequest) {
 561                 case USB_REQ_SET_ADDRESS:
 562                         /* set_address may come when a device is reset */
 563                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
 564                                  ctrlreq->wValue, vdev->rhport);
 565
 566                         usb_put_dev(vdev->udev);
 567                         vdev->udev = usb_get_dev(urb->dev);
 568
 569                         spin_lock(&vdev->ud.lock);
 570                         vdev->ud.status = VDEV_ST_USED;
 571                         spin_unlock(&vdev->ud.lock);
 572
 573                         if (urb->status == -EINPROGRESS) {
 574                                 /* This request is successfully completed. */
 575                                 /* If not -EINPROGRESS, possibly unlinked. */
 576                                 urb->status = 0;
 577                         }
 578
 579                         goto no_need_xmit;
 580
 581                 case USB_REQ_GET_DESCRIPTOR:
 582                         if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
 583                                 usbip_dbg_vhci_hc(
 584                                         "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
 585
 586                         usb_put_dev(vdev->udev);
 587                         vdev->udev = usb_get_dev(urb->dev);
 588                         goto out;
 589
 590                 default:
 591                         /* NOT REACHED */
 592                         dev_err(dev,
 593                                 "invalid request to devnum 0 bRequest %u, wValue %u\n",
 594                                 ctrlreq->bRequest,
 595                                 ctrlreq->wValue);
 596                         ret =  -EINVAL;
 597                         goto no_need_xmit;
 598                 }
 599
 600         }
 601
 602 out:
 603         vhci_tx_urb(urb);
 604         spin_unlock_irqrestore(&vhci->lock, flags);
 605
 606         return 0;
 607
 608 no_need_xmit:
 609         usb_hcd_unlink_urb_from_ep(hcd, urb);
 610 no_need_unlink:
 611         spin_unlock_irqrestore(&vhci->lock, flags);
 612         if (!ret)
 613                 usb_hcd_giveback_urb(hcd, urb, urb->status);
 614         return ret;
 615 }
 616
 617 /*
 618  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 619  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 620  * back its urb. For the driver unlinking the urb, the content of the urb is
 621  * not important, but the calling to its completion handler is important; the
 622  * completion of unlinking is notified by the completion handler.
 623  *
 624  *
 625  * CLIENT SIDE
 626  *
 627  * - When vhci_hcd receives RET_SUBMIT,
 628  *
 629  *      - case 1a). the urb of the pdu is not unlinking.
 630  *              - normal case
 631  *              => just give back the urb
 632  *
 633  *      - case 1b). the urb of the pdu is unlinking.
 634  *              - usbip.ko will return a reply of the unlinking request.
 635  *              => give back the urb now and go to case 2b).
 636  *
 637  * - When vhci_hcd receives RET_UNLINK,
 638  *
 639  *      - case 2a). a submit request is still pending in vhci_hcd.
 640  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 641  *                completed there.
 642  *              => free a pending submit request
 643  *              => notify unlink completeness by giving back the urb
 644  *
 645  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 646  *              - urb was already given back to the core driver.
 647  *              => do not give back the urb
 648  *
 649  *
 650  * SERVER SIDE
 651  *
 652  * - When usbip receives CMD_UNLINK,
 653  *
 654  *      - case 3a). the urb of the unlink request is now in submission.
 655  *              => do usb_unlink_urb().
 656  *              => after the unlink is completed, send RET_UNLINK.
 657  *
 658  *      - case 3b). the urb of the unlink request is not in submission.
 659  *              - may be already completed or never be received
 660  *              => send RET_UNLINK
 661  *
 662  */
 663 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 664 {
 665         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 666         struct vhci_priv *priv;
 667         struct vhci_device *vdev;
 668         unsigned long flags;
 669
 670         pr_info("dequeue a urb %p\n", urb);
 671
 672         spin_lock_irqsave(&vhci->lock, flags);
 673
 674         priv = urb->hcpriv;
 675         if (!priv) {
 676                 /* URB was never linked! or will be soon given back by
 677                  * vhci_rx. */
 678                 spin_unlock_irqrestore(&vhci->lock, flags);
 679                 return -EIDRM;
 680         }
 681
 682         {
 683                 int ret = 0;
 684
 685                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 686                 if (ret) {
 687                         spin_unlock_irqrestore(&vhci->lock, flags);
 688                         return ret;
 689                 }
 690         }
 691
 692          /* send unlink request here? */
 693         vdev = priv->vdev;
 694
 695         if (!vdev->ud.tcp_socket) {
 696                 /* tcp connection is closed */
 697                 spin_lock(&vdev->priv_lock);
 698
 699                 pr_info("device %p seems to be disconnected\n", vdev);
 700                 list_del(&priv->list);
 701                 kfree(priv);
 702                 urb->hcpriv = NULL;
 703
 704                 spin_unlock(&vdev->priv_lock);
 705
 706                 /*
 707                  * If tcp connection is alive, we have sent CMD_UNLINK.
 708                  * vhci_rx will receive RET_UNLINK and give back the URB.
 709                  * Otherwise, we give back it here.
 710                  */
 711                 pr_info("gives back urb %p\n", urb);
 712
 713                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 714
 715                 spin_unlock_irqrestore(&vhci->lock, flags);
 716                 usb_hcd_giveback_urb(vhci_to_hcd(vhci), urb, urb->status);
 717                 spin_lock_irqsave(&vhci->lock, flags);
 718
 719         } else {
 720                 /* tcp connection is alive */
 721                 struct vhci_unlink *unlink;
 722
 723                 spin_lock(&vdev->priv_lock);
 724
 725                 /* setup CMD_UNLINK pdu */
 726                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 727                 if (!unlink) {
 728                         spin_unlock(&vdev->priv_lock);
 729                         spin_unlock_irqrestore(&vhci->lock, flags);
 730                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 731                         return -ENOMEM;
 732                 }
 733
 734                 unlink->seqnum = atomic_inc_return(&vhci->seqnum);
 735                 if (unlink->seqnum == 0xffff)
 736                         pr_info("seqnum max\n");
 737
 738                 unlink->unlink_seqnum = priv->seqnum;
 739
 740                 pr_info("device %p seems to be still connected\n", vdev);
 741
 742                 /* send cmd_unlink and try to cancel the pending URB in the
 743                  * peer */
 744                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 745                 wake_up(&vdev->waitq_tx);
 746
 747                 spin_unlock(&vdev->priv_lock);
 748         }
 749
 750         spin_unlock_irqrestore(&vhci->lock, flags);
 751
 752         usbip_dbg_vhci_hc("leave\n");
 753         return 0;
 754 }
 755
 756 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 757 {
 758         struct vhci_hcd *vhci = vdev_to_vhci(vdev);
 759         struct usb_hcd *hcd = vhci_to_hcd(vhci);
 760         struct vhci_unlink *unlink, *tmp;
 761         unsigned long flags;
 762
 763         spin_lock_irqsave(&vhci->lock, flags);
 764         spin_lock(&vdev->priv_lock);
 765
 766         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 767                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 768                 list_del(&unlink->list);
 769                 kfree(unlink);
 770         }
 771
 772         while (!list_empty(&vdev->unlink_rx)) {
 773                 struct urb *urb;
 774
 775                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 776                         list);
 777
 778                 /* give back URB of unanswered unlink request */
 779                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 780
 781                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 782                 if (!urb) {
 783                         pr_info("the urb (seqnum %lu) was already given back\n",
 784                                 unlink->unlink_seqnum);
 785                         list_del(&unlink->list);
 786                         kfree(unlink);
 787                         continue;
 788                 }
 789
 790                 urb->status = -ENODEV;
 791
 792                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 793
 794                 list_del(&unlink->list);
 795
 796                 spin_unlock(&vdev->priv_lock);
 797                 spin_unlock_irqrestore(&vhci->lock, flags);
 798
 799                 usb_hcd_giveback_urb(hcd, urb, urb->status);
 800
 801                 spin_lock_irqsave(&vhci->lock, flags);
 802                 spin_lock(&vdev->priv_lock);
 803
 804                 kfree(unlink);
 805         }
 806
 807         spin_unlock(&vdev->priv_lock);
 808         spin_unlock_irqrestore(&vhci->lock, flags);
 809 }
 810
 811 /*
 812  * The important thing is that only one context begins cleanup.
 813  * This is why error handling and cleanup become simple.
 814  * We do not want to consider race condition as possible.
 815  */
 816 static void vhci_shutdown_connection(struct usbip_device *ud)
 817 {
 818         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 819
 820         /* need this? see stub_dev.c */
 821         if (ud->tcp_socket) {
 822                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 823                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 824         }
 825
 826         /* kill threads related to this sdev */
 827         if (vdev->ud.tcp_rx) {
 828                 kthread_stop_put(vdev->ud.tcp_rx);
 829                 vdev->ud.tcp_rx = NULL;
 830         }
 831         if (vdev->ud.tcp_tx) {
 832                 kthread_stop_put(vdev->ud.tcp_tx);
 833                 vdev->ud.tcp_tx = NULL;
 834         }
 835         pr_info("stop threads\n");
 836
 837         /* active connection is closed */
 838         if (vdev->ud.tcp_socket) {
 839                 sockfd_put(vdev->ud.tcp_socket);
 840                 vdev->ud.tcp_socket = NULL;
 841         }
 842         pr_info("release socket\n");
 843
 844         vhci_device_unlink_cleanup(vdev);
 845
 846         /*
 847          * rh_port_disconnect() is a trigger of ...
 848          *   usb_disable_device():
 849          *      disable all the endpoints for a USB device.
 850          *   usb_disable_endpoint():
 851          *      disable endpoints. pending urbs are unlinked(dequeued).
 852          *
 853          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 854          * detached device should release used urbs in a cleanup function (i.e.
 855          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 856          * pushed urbs and their private data in this function.
 857          *
 858          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 859          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 860          * gives back pushed urbs and frees their private data by request of
 861          * the cleanup function of a USB driver. When unlinking a urb with an
 862          * active connection, vhci_dequeue() does not give back the urb which
 863          * is actually given back by vhci_rx after receiving its return pdu.
 864          *
 865          */
 866         rh_port_disconnect(vdev);
 867
 868         pr_info("disconnect device\n");
 869 }
 870
 871
 872 static void vhci_device_reset(struct usbip_device *ud)
 873 {
 874         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 875         unsigned long flags;
 876
 877         spin_lock_irqsave(&ud->lock, flags);
 878
 879         vdev->speed  = 0;
 880         vdev->devid  = 0;
 881
 882         usb_put_dev(vdev->udev);
 883         vdev->udev = NULL;
 884
 885         if (ud->tcp_socket) {
 886                 sockfd_put(ud->tcp_socket);
 887                 ud->tcp_socket = NULL;
 888         }
 889         ud->status = VDEV_ST_NULL;
 890
 891         spin_unlock_irqrestore(&ud->lock, flags);
 892 }
 893
 894 static void vhci_device_unusable(struct usbip_device *ud)
 895 {
 896         unsigned long flags;
 897
 898         spin_lock_irqsave(&ud->lock, flags);
 899         ud->status = VDEV_ST_ERROR;
 900         spin_unlock_irqrestore(&ud->lock, flags);
 901 }
 902
 903 static void vhci_device_init(struct vhci_device *vdev)
 904 {
 905         memset(vdev, 0, sizeof(struct vhci_device));
 906
 907         vdev->ud.side   = USBIP_VHCI;
 908         vdev->ud.status = VDEV_ST_NULL;
 909         spin_lock_init(&vdev->ud.lock);
 910
 911         INIT_LIST_HEAD(&vdev->priv_rx);
 912         INIT_LIST_HEAD(&vdev->priv_tx);
 913         INIT_LIST_HEAD(&vdev->unlink_tx);
 914         INIT_LIST_HEAD(&vdev->unlink_rx);
 915         spin_lock_init(&vdev->priv_lock);
 916
 917         init_waitqueue_head(&vdev->waitq_tx);
 918
 919         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 920         vdev->ud.eh_ops.reset = vhci_device_reset;
 921         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 922
 923         usbip_start_eh(&vdev->ud);
 924 }
 925
 926 static int hcd_name_to_id(const char *name)
 927 {
 928         char *c;
 929         long val;
 930         int ret;
 931
 932         c = strchr(name, '.');
 933         if (c == NULL)
 934                 return 0;
 935
 936         ret = kstrtol(c+1, 10, &val);
 937         if (ret < 0)
 938                 return ret;
 939
 940         return val;
 941 }
 942
 943 static int vhci_start(struct usb_hcd *hcd)
 944 {
 945         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 946         int id, rhport;
 947         int err = 0;
 948
 949         usbip_dbg_vhci_hc("enter vhci_start\n");
 950
 951         /* initialize private data of usb_hcd */
 952
 953         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 954                 struct vhci_device *vdev = &vhci->vdev[rhport];
 955
 956                 vhci_device_init(vdev);
 957                 vdev->rhport = rhport;
 958         }
 959
 960         atomic_set(&vhci->seqnum, 0);
 961         spin_lock_init(&vhci->lock);
 962
 963         hcd->power_budget = 0; /* no limit */
 964         hcd->uses_new_polling = 1;
 965
 966         id = hcd_name_to_id(hcd_name(hcd));
 967         if (id < 0) {
 968                 pr_err("invalid vhci name %s\n", hcd_name(hcd));
 969                 return -EINVAL;
 970         }
 971
 972         /* vhci_hcd is now ready to be controlled through sysfs */
 973         if (id == 0) {
 974                 err = vhci_init_attr_group();
 975                 if (err) {
 976                         pr_err("init attr group\n");
 977                         return err;
 978                 }
 979                 err = sysfs_create_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
 980                 if (err) {
 981                         pr_err("create sysfs files\n");
 982                         vhci_finish_attr_group();
 983                         return err;
 984                 }
 985                 pr_info("created sysfs %s\n", hcd_name(hcd));
 986         }
 987
 988         return 0;
 989 }
 990
 991 static void vhci_stop(struct usb_hcd *hcd)
 992 {
 993         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 994         int id, rhport;
 995
 996         usbip_dbg_vhci_hc("stop VHCI controller\n");
 997
 998         /* 1. remove the userland interface of vhci_hcd */
 999         id = hcd_name_to_id(hcd_name(hcd));
1000         if (id == 0) {
1001                 sysfs_remove_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
1002                 vhci_finish_attr_group();
1003         }
1004
1005         /* 2. shutdown all the ports of vhci_hcd */
1006         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
1007                 struct vhci_device *vdev = &vhci->vdev[rhport];
1008
1009                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
1010                 usbip_stop_eh(&vdev->ud);
1011         }
1012 }
1013
1014 static int vhci_get_frame_number(struct usb_hcd *hcd)
1015 {
1016         dev_err_ratelimited(&hcd->self.root_hub->dev, "Not yet implemented\n");
1017         return 0;
1018 }
1019
1020 #ifdef CONFIG_PM
1021
1022 /* FIXME: suspend/resume */
1023 static int vhci_bus_suspend(struct usb_hcd *hcd)
1024 {
1025         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1026         unsigned long flags;
1027
1028         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1029
1030         spin_lock_irqsave(&vhci->lock, flags);
1031         hcd->state = HC_STATE_SUSPENDED;
1032         spin_unlock_irqrestore(&vhci->lock, flags);
1033
1034         return 0;
1035 }
1036
1037 static int vhci_bus_resume(struct usb_hcd *hcd)
1038 {
1039         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1040         int rc = 0;
1041         unsigned long flags;
1042
1043         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1044
1045         spin_lock_irqsave(&vhci->lock, flags);
1046         if (!HCD_HW_ACCESSIBLE(hcd))
1047                 rc = -ESHUTDOWN;
1048         else
1049                 hcd->state = HC_STATE_RUNNING;
1050         spin_unlock_irqrestore(&vhci->lock, flags);
1051
1052         return rc;
1053 }
1054
1055 #else
1056
1057 #define vhci_bus_suspend      NULL
1058 #define vhci_bus_resume       NULL
1059 #endif
1060
1061 static struct hc_driver vhci_hc_driver = {
1062         .description    = driver_name,
1063         .product_desc   = driver_desc,
1064         .hcd_priv_size  = sizeof(struct vhci_hcd),
1065
1066         .flags          = HCD_USB2,
1067
1068         .start          = vhci_start,
1069         .stop           = vhci_stop,
1070
1071         .urb_enqueue    = vhci_urb_enqueue,
1072         .urb_dequeue    = vhci_urb_dequeue,
1073
1074         .get_frame_number = vhci_get_frame_number,
1075
1076         .hub_status_data = vhci_hub_status,
1077         .hub_control    = vhci_hub_control,
1078         .bus_suspend    = vhci_bus_suspend,
1079         .bus_resume     = vhci_bus_resume,
1080 };
1081
1082 static int vhci_hcd_probe(struct platform_device *pdev)
1083 {
1084         struct usb_hcd          *hcd;
1085         int                     ret;
1086
1087         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1088
1089         /*
1090          * Allocate and initialize hcd.
1091          * Our private data is also allocated automatically.
1092          */
1093         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1094         if (!hcd) {
1095                 pr_err("create hcd failed\n");
1096                 return -ENOMEM;
1097         }
1098         hcd->has_tt = 1;
1099
1100         /*
1101          * Finish generic HCD structure initialization and register.
1102          * Call the driver's reset() and start() routines.
1103          */
1104         ret = usb_add_hcd(hcd, 0, 0);
1105         if (ret != 0) {
1106                 pr_err("usb_add_hcd failed %d\n", ret);
1107                 usb_put_hcd(hcd);
1108                 return ret;
1109         }
1110
1111         usbip_dbg_vhci_hc("bye\n");
1112         return 0;
1113 }
1114
1115 static int vhci_hcd_remove(struct platform_device *pdev)
1116 {
1117         struct usb_hcd  *hcd;
1118
1119         hcd = platform_get_drvdata(pdev);
1120         if (!hcd)
1121                 return 0;
1122
1123         /*
1124          * Disconnects the root hub,
1125          * then reverses the effects of usb_add_hcd(),
1126          * invoking the HCD's stop() methods.
1127          */
1128         usb_remove_hcd(hcd);
1129         usb_put_hcd(hcd);
1130
1131         return 0;
1132 }
1133
1134 #ifdef CONFIG_PM
1135
1136 /* what should happen for USB/IP under suspend/resume? */
1137 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1138 {
1139         struct usb_hcd *hcd;
1140         struct vhci_hcd *vhci;
1141         int rhport;
1142         int connected = 0;
1143         int ret = 0;
1144         unsigned long flags;
1145
1146         hcd = platform_get_drvdata(pdev);
1147         if (!hcd)
1148                 return 0;
1149         vhci = hcd_to_vhci(hcd);
1150
1151         spin_lock_irqsave(&vhci->lock, flags);
1152
1153         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++)
1154                 if (vhci->port_status[rhport] & USB_PORT_STAT_CONNECTION)
1155                         connected += 1;
1156
1157         spin_unlock_irqrestore(&vhci->lock, flags);
1158
1159         if (connected > 0) {
1160                 dev_info(&pdev->dev,
1161                          "We have %d active connection%s. Do not suspend.\n",
1162                          connected, (connected == 1 ? "" : "s"));
1163                 ret =  -EBUSY;
1164         } else {
1165                 dev_info(&pdev->dev, "suspend vhci_hcd");
1166                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1167         }
1168
1169         return ret;
1170 }
1171
1172 static int vhci_hcd_resume(struct platform_device *pdev)
1173 {
1174         struct usb_hcd *hcd;
1175
1176         dev_dbg(&pdev->dev, "%s\n", __func__);
1177
1178         hcd = platform_get_drvdata(pdev);
1179         if (!hcd)
1180                 return 0;
1181         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1182         usb_hcd_poll_rh_status(hcd);
1183
1184         return 0;
1185 }
1186
1187 #else
1188
1189 #define vhci_hcd_suspend        NULL
1190 #define vhci_hcd_resume         NULL
1191
1192 #endif
1193
1194 static struct platform_driver vhci_driver = {
1195         .probe  = vhci_hcd_probe,
1196         .remove = vhci_hcd_remove,
1197         .suspend = vhci_hcd_suspend,
1198         .resume = vhci_hcd_resume,
1199         .driver = {
1200                 .name = driver_name,
1201         },
1202 };
1203
1204 static int add_platform_device(int id)
1205 {
1206         struct platform_device *pdev;
1207         int dev_nr;
1208
1209         if (id == 0)
1210                 dev_nr = -1;
1211         else
1212                 dev_nr = id;
1213
1214         pdev = platform_device_register_simple(driver_name, dev_nr, NULL, 0);
1215         if (IS_ERR(pdev))
1216                 return PTR_ERR(pdev);
1217
1218         *(vhci_pdevs + id) = pdev;
1219         return 0;
1220 }
1221
1222 static void del_platform_devices(void)
1223 {
1224         struct platform_device *pdev;
1225         int i;
1226
1227         for (i = 0; i < vhci_num_controllers; i++) {
1228                 pdev = *(vhci_pdevs + i);
1229                 if (pdev != NULL)
1230                         platform_device_unregister(pdev);
1231                 *(vhci_pdevs + i) = NULL;
1232         }
1233         sysfs_remove_link(&platform_bus.kobj, driver_name);
1234 }
1235
1236 static int __init vhci_hcd_init(void)
1237 {
1238         int i, ret;
1239
1240         if (usb_disabled())
1241                 return -ENODEV;
1242
1243         if (vhci_num_controllers < 1)
1244                 vhci_num_controllers = 1;
1245
1246         vhci_pdevs = kcalloc(vhci_num_controllers, sizeof(void *), GFP_KERNEL);
1247         if (vhci_pdevs == NULL)
1248                 return -ENOMEM;
1249
1250         ret = platform_driver_register(&vhci_driver);
1251         if (ret)
1252                 goto err_driver_register;
1253
1254         for (i = 0; i < vhci_num_controllers; i++) {
1255                 ret = add_platform_device(i);
1256                 if (ret)
1257                         goto err_platform_device_register;
1258         }
1259
1260         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1261         return ret;
1262
1263 err_platform_device_register:
1264         del_platform_devices();
1265         platform_driver_unregister(&vhci_driver);
1266 err_driver_register:
1267         kfree(vhci_pdevs);
1268         return ret;
1269 }
1270
1271 static void __exit vhci_hcd_exit(void)
1272 {
1273         del_platform_devices();
1274         platform_driver_unregister(&vhci_driver);
1275         kfree(vhci_pdevs);
1276 }
1277
1278 module_init(vhci_hcd_init);
1279 module_exit(vhci_hcd_exit);
1280
1281 MODULE_AUTHOR(DRIVER_AUTHOR);
1282 MODULE_DESCRIPTION(DRIVER_DESC);
1283 MODULE_LICENSE("GPL");
1284 MODULE_VERSION(USBIP_VERSION);