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         int width;
 239
 240         memset(desc, 0, sizeof(*desc));
 241         desc->bDescriptorType = USB_DT_HUB;
 242         desc->wHubCharacteristics = cpu_to_le16(
 243                 HUB_CHAR_INDV_PORT_LPSM | HUB_CHAR_COMMON_OCPM);
 244
 245         desc->bNbrPorts = VHCI_HC_PORTS;
 246         BUILD_BUG_ON(VHCI_HC_PORTS > USB_MAXCHILDREN);
 247         width = desc->bNbrPorts / 8 + 1;
 248         desc->bDescLength = USB_DT_HUB_NONVAR_SIZE + 2 * width;
 249         memset(&desc->u.hs.DeviceRemovable[0], 0, width);
 250         memset(&desc->u.hs.DeviceRemovable[width], 0xff, width);
 251 }
 252
 253 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 254                             u16 wIndex, char *buf, u16 wLength)
 255 {
 256         struct vhci_hcd *dum;
 257         int             retval = 0;
 258         int             rhport;
 259         unsigned long   flags;
 260
 261         u32 prev_port_status[VHCI_HC_PORTS];
 262
 263         if (!HCD_HW_ACCESSIBLE(hcd))
 264                 return -ETIMEDOUT;
 265
 266         /*
 267          * NOTE:
 268          * wIndex shows the port number and begins from 1.
 269          */
 270         usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 271                           wIndex);
 272         if (wIndex > VHCI_HC_PORTS)
 273                 pr_err("invalid port number %d\n", wIndex);
 274         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 275
 276         dum = hcd_to_vhci(hcd);
 277
 278         spin_lock_irqsave(&dum->lock, flags);
 279
 280         /* store old status and compare now and old later */
 281         if (usbip_dbg_flag_vhci_rh) {
 282                 memcpy(prev_port_status, dum->port_status,
 283                         sizeof(prev_port_status));
 284         }
 285
 286         switch (typeReq) {
 287         case ClearHubFeature:
 288                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
 289                 break;
 290         case ClearPortFeature:
 291                 switch (wValue) {
 292                 case USB_PORT_FEAT_SUSPEND:
 293                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
 294                                 /* 20msec signaling */
 295                                 dum->resuming = 1;
 296                                 dum->re_timeout =
 297                                         jiffies + msecs_to_jiffies(20);
 298                         }
 299                         break;
 300                 case USB_PORT_FEAT_POWER:
 301                         usbip_dbg_vhci_rh(
 302                                 " ClearPortFeature: USB_PORT_FEAT_POWER\n");
 303                         dum->port_status[rhport] &= ~USB_PORT_STAT_POWER;
 304                         dum->resuming = 0;
 305                         break;
 306                 case USB_PORT_FEAT_C_RESET:
 307                         usbip_dbg_vhci_rh(
 308                                 " ClearPortFeature: USB_PORT_FEAT_C_RESET\n");
 309                         switch (dum->vdev[rhport].speed) {
 310                         case USB_SPEED_HIGH:
 311                                 dum->port_status[rhport] |=
 312                                         USB_PORT_STAT_HIGH_SPEED;
 313                                 break;
 314                         case USB_SPEED_LOW:
 315                                 dum->port_status[rhport] |=
 316                                         USB_PORT_STAT_LOW_SPEED;
 317                                 break;
 318                         default:
 319                                 break;
 320                         }
 321                 default:
 322                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 323                                           wValue);
 324                         dum->port_status[rhport] &= ~(1 << wValue);
 325                         break;
 326                 }
 327                 break;
 328         case GetHubDescriptor:
 329                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 330                 hub_descriptor((struct usb_hub_descriptor *) buf);
 331                 break;
 332         case GetHubStatus:
 333                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 334                 *(__le32 *) buf = cpu_to_le32(0);
 335                 break;
 336         case GetPortStatus:
 337                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 338                 if (wIndex > VHCI_HC_PORTS || wIndex < 1) {
 339                         pr_err("invalid port number %d\n", wIndex);
 340                         retval = -EPIPE;
 341                 }
 342
 343                 /* we do not care about resume. */
 344
 345                 /* whoever resets or resumes must GetPortStatus to
 346                  * complete it!!
 347                  */
 348                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 349                         dum->port_status[rhport] |=
 350                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 351                         dum->port_status[rhport] &=
 352                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 353                         dum->resuming = 0;
 354                         dum->re_timeout = 0;
 355                 }
 356
 357                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 358                     0 && time_after(jiffies, dum->re_timeout)) {
 359                         dum->port_status[rhport] |=
 360                                 (1 << USB_PORT_FEAT_C_RESET);
 361                         dum->port_status[rhport] &=
 362                                 ~(1 << USB_PORT_FEAT_RESET);
 363                         dum->re_timeout = 0;
 364
 365                         if (dum->vdev[rhport].ud.status ==
 366                             VDEV_ST_NOTASSIGNED) {
 367                                 usbip_dbg_vhci_rh(
 368                                         " enable rhport %d (status %u)\n",
 369                                         rhport,
 370                                         dum->vdev[rhport].ud.status);
 371                                 dum->port_status[rhport] |=
 372                                         USB_PORT_STAT_ENABLE;
 373                         }
 374                 }
 375                 ((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 376                 ((__le16 *) buf)[1] =
 377                         cpu_to_le16(dum->port_status[rhport] >> 16);
 378
 379                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 380                                   ((u16 *)buf)[1]);
 381                 break;
 382         case SetHubFeature:
 383                 usbip_dbg_vhci_rh(" SetHubFeature\n");
 384                 retval = -EPIPE;
 385                 break;
 386         case SetPortFeature:
 387                 switch (wValue) {
 388                 case USB_PORT_FEAT_SUSPEND:
 389                         usbip_dbg_vhci_rh(
 390                                 " SetPortFeature: USB_PORT_FEAT_SUSPEND\n");
 391                         break;
 392                 case USB_PORT_FEAT_RESET:
 393                         usbip_dbg_vhci_rh(
 394                                 " SetPortFeature: USB_PORT_FEAT_RESET\n");
 395                         /* if it's already running, disconnect first */
 396                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 397                                 dum->port_status[rhport] &=
 398                                         ~(USB_PORT_STAT_ENABLE |
 399                                           USB_PORT_STAT_LOW_SPEED |
 400                                           USB_PORT_STAT_HIGH_SPEED);
 401                                 /* FIXME test that code path! */
 402                         }
 403                         /* 50msec reset signaling */
 404                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
 405
 406                         /* FALLTHROUGH */
 407                 default:
 408                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 409                                           wValue);
 410                         dum->port_status[rhport] |= (1 << wValue);
 411                         break;
 412                 }
 413                 break;
 414
 415         default:
 416                 pr_err("default: no such request\n");
 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         struct platform_device *pdev;
 440         struct usb_hcd *hcd;
 441         struct vhci_hcd *vhci;
 442         int pdev_nr, rhport;
 443
 444         if (!udev)
 445                 return NULL;
 446
 447         for (pdev_nr = 0; pdev_nr < vhci_num_controllers; pdev_nr++) {
 448                 pdev = *(vhci_pdevs + pdev_nr);
 449                 if (pdev == NULL)
 450                         continue;
 451                 hcd = platform_get_drvdata(pdev);
 452                 if (hcd == NULL)
 453                         continue;
 454                 vhci = hcd_to_vhci(hcd);
 455                 for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 456                         if (vhci->vdev[rhport].udev == udev)
 457                                 return &vhci->vdev[rhport];
 458                 }
 459         }
 460
 461         return NULL;
 462 }
 463
 464 static void vhci_tx_urb(struct urb *urb)
 465 {
 466         struct vhci_device *vdev = get_vdev(urb->dev);
 467         struct vhci_priv *priv;
 468         struct vhci_hcd *vhci = vdev_to_vhci(vdev);
 469         unsigned long flags;
 470
 471         if (!vdev) {
 472                 pr_err("could not get virtual device");
 473                 return;
 474         }
 475
 476         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 477         if (!priv) {
 478                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 479                 return;
 480         }
 481
 482         spin_lock_irqsave(&vdev->priv_lock, flags);
 483
 484         priv->seqnum = atomic_inc_return(&vhci->seqnum);
 485         if (priv->seqnum == 0xffff)
 486                 dev_info(&urb->dev->dev, "seqnum max\n");
 487
 488         priv->vdev = vdev;
 489         priv->urb = urb;
 490
 491         urb->hcpriv = (void *) priv;
 492
 493         list_add_tail(&priv->list, &vdev->priv_tx);
 494
 495         wake_up(&vdev->waitq_tx);
 496         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 497 }
 498
 499 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 500                             gfp_t mem_flags)
 501 {
 502         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 503         struct device *dev = &urb->dev->dev;
 504         u8 portnum = urb->dev->portnum;
 505         int ret = 0;
 506         struct vhci_device *vdev;
 507         unsigned long flags;
 508
 509         if (portnum > VHCI_HC_PORTS) {
 510                 pr_err("invalid port number %d\n", portnum);
 511                 return -ENODEV;
 512         }
 513         vdev = &vhci->vdev[portnum-1];
 514
 515         /* patch to usb_sg_init() is in 2.5.60 */
 516         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 517
 518         spin_lock_irqsave(&vhci->lock, flags);
 519
 520         if (urb->status != -EINPROGRESS) {
 521                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 522                 spin_unlock_irqrestore(&vhci->lock, flags);
 523                 return urb->status;
 524         }
 525
 526         /* refuse enqueue for dead connection */
 527         spin_lock(&vdev->ud.lock);
 528         if (vdev->ud.status == VDEV_ST_NULL ||
 529             vdev->ud.status == VDEV_ST_ERROR) {
 530                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 531                 spin_unlock(&vdev->ud.lock);
 532                 spin_unlock_irqrestore(&vhci->lock, flags);
 533                 return -ENODEV;
 534         }
 535         spin_unlock(&vdev->ud.lock);
 536
 537         ret = usb_hcd_link_urb_to_ep(hcd, urb);
 538         if (ret)
 539                 goto no_need_unlink;
 540
 541         /*
 542          * The enumeration process is as follows;
 543          *
 544          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 545          *     to get max packet length of default pipe
 546          *
 547          *  2. Set_Address request to DevAddr(0) EndPoint(0)
 548          *
 549          */
 550         if (usb_pipedevice(urb->pipe) == 0) {
 551                 __u8 type = usb_pipetype(urb->pipe);
 552                 struct usb_ctrlrequest *ctrlreq =
 553                         (struct usb_ctrlrequest *) urb->setup_packet;
 554
 555                 if (type != PIPE_CONTROL || !ctrlreq) {
 556                         dev_err(dev, "invalid request to devnum 0\n");
 557                         ret = -EINVAL;
 558                         goto no_need_xmit;
 559                 }
 560
 561                 switch (ctrlreq->bRequest) {
 562                 case USB_REQ_SET_ADDRESS:
 563                         /* set_address may come when a device is reset */
 564                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
 565                                  ctrlreq->wValue, vdev->rhport);
 566
 567                         usb_put_dev(vdev->udev);
 568                         vdev->udev = usb_get_dev(urb->dev);
 569
 570                         spin_lock(&vdev->ud.lock);
 571                         vdev->ud.status = VDEV_ST_USED;
 572                         spin_unlock(&vdev->ud.lock);
 573
 574                         if (urb->status == -EINPROGRESS) {
 575                                 /* This request is successfully completed. */
 576                                 /* If not -EINPROGRESS, possibly unlinked. */
 577                                 urb->status = 0;
 578                         }
 579
 580                         goto no_need_xmit;
 581
 582                 case USB_REQ_GET_DESCRIPTOR:
 583                         if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
 584                                 usbip_dbg_vhci_hc(
 585                                         "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
 586
 587                         usb_put_dev(vdev->udev);
 588                         vdev->udev = usb_get_dev(urb->dev);
 589                         goto out;
 590
 591                 default:
 592                         /* NOT REACHED */
 593                         dev_err(dev,
 594                                 "invalid request to devnum 0 bRequest %u, wValue %u\n",
 595                                 ctrlreq->bRequest,
 596                                 ctrlreq->wValue);
 597                         ret =  -EINVAL;
 598                         goto no_need_xmit;
 599                 }
 600
 601         }
 602
 603 out:
 604         vhci_tx_urb(urb);
 605         spin_unlock_irqrestore(&vhci->lock, flags);
 606
 607         return 0;
 608
 609 no_need_xmit:
 610         usb_hcd_unlink_urb_from_ep(hcd, urb);
 611 no_need_unlink:
 612         spin_unlock_irqrestore(&vhci->lock, flags);
 613         if (!ret)
 614                 usb_hcd_giveback_urb(hcd, urb, urb->status);
 615         return ret;
 616 }
 617
 618 /*
 619  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 620  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 621  * back its urb. For the driver unlinking the urb, the content of the urb is
 622  * not important, but the calling to its completion handler is important; the
 623  * completion of unlinking is notified by the completion handler.
 624  *
 625  *
 626  * CLIENT SIDE
 627  *
 628  * - When vhci_hcd receives RET_SUBMIT,
 629  *
 630  *      - case 1a). the urb of the pdu is not unlinking.
 631  *              - normal case
 632  *              => just give back the urb
 633  *
 634  *      - case 1b). the urb of the pdu is unlinking.
 635  *              - usbip.ko will return a reply of the unlinking request.
 636  *              => give back the urb now and go to case 2b).
 637  *
 638  * - When vhci_hcd receives RET_UNLINK,
 639  *
 640  *      - case 2a). a submit request is still pending in vhci_hcd.
 641  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 642  *                completed there.
 643  *              => free a pending submit request
 644  *              => notify unlink completeness by giving back the urb
 645  *
 646  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 647  *              - urb was already given back to the core driver.
 648  *              => do not give back the urb
 649  *
 650  *
 651  * SERVER SIDE
 652  *
 653  * - When usbip receives CMD_UNLINK,
 654  *
 655  *      - case 3a). the urb of the unlink request is now in submission.
 656  *              => do usb_unlink_urb().
 657  *              => after the unlink is completed, send RET_UNLINK.
 658  *
 659  *      - case 3b). the urb of the unlink request is not in submission.
 660  *              - may be already completed or never be received
 661  *              => send RET_UNLINK
 662  *
 663  */
 664 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 665 {
 666         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 667         struct vhci_priv *priv;
 668         struct vhci_device *vdev;
 669         unsigned long flags;
 670
 671         spin_lock_irqsave(&vhci->lock, flags);
 672
 673         priv = urb->hcpriv;
 674         if (!priv) {
 675                 /* URB was never linked! or will be soon given back by
 676                  * vhci_rx. */
 677                 spin_unlock_irqrestore(&vhci->lock, flags);
 678                 return -EIDRM;
 679         }
 680
 681         {
 682                 int ret = 0;
 683
 684                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 685                 if (ret) {
 686                         spin_unlock_irqrestore(&vhci->lock, flags);
 687                         return ret;
 688                 }
 689         }
 690
 691          /* send unlink request here? */
 692         vdev = priv->vdev;
 693
 694         if (!vdev->ud.tcp_socket) {
 695                 /* tcp connection is closed */
 696                 spin_lock(&vdev->priv_lock);
 697
 698                 list_del(&priv->list);
 699                 kfree(priv);
 700                 urb->hcpriv = NULL;
 701
 702                 spin_unlock(&vdev->priv_lock);
 703
 704                 /*
 705                  * If tcp connection is alive, we have sent CMD_UNLINK.
 706                  * vhci_rx will receive RET_UNLINK and give back the URB.
 707                  * Otherwise, we give back it here.
 708                  */
 709                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 710
 711                 spin_unlock_irqrestore(&vhci->lock, flags);
 712                 usb_hcd_giveback_urb(vhci_to_hcd(vhci), urb, urb->status);
 713                 spin_lock_irqsave(&vhci->lock, flags);
 714
 715         } else {
 716                 /* tcp connection is alive */
 717                 struct vhci_unlink *unlink;
 718
 719                 spin_lock(&vdev->priv_lock);
 720
 721                 /* setup CMD_UNLINK pdu */
 722                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 723                 if (!unlink) {
 724                         spin_unlock(&vdev->priv_lock);
 725                         spin_unlock_irqrestore(&vhci->lock, flags);
 726                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 727                         return -ENOMEM;
 728                 }
 729
 730                 unlink->seqnum = atomic_inc_return(&vhci->seqnum);
 731                 if (unlink->seqnum == 0xffff)
 732                         pr_info("seqnum max\n");
 733
 734                 unlink->unlink_seqnum = priv->seqnum;
 735
 736                 /* send cmd_unlink and try to cancel the pending URB in the
 737                  * peer */
 738                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 739                 wake_up(&vdev->waitq_tx);
 740
 741                 spin_unlock(&vdev->priv_lock);
 742         }
 743
 744         spin_unlock_irqrestore(&vhci->lock, flags);
 745
 746         usbip_dbg_vhci_hc("leave\n");
 747         return 0;
 748 }
 749
 750 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 751 {
 752         struct vhci_hcd *vhci = vdev_to_vhci(vdev);
 753         struct usb_hcd *hcd = vhci_to_hcd(vhci);
 754         struct vhci_unlink *unlink, *tmp;
 755         unsigned long flags;
 756
 757         spin_lock_irqsave(&vhci->lock, flags);
 758         spin_lock(&vdev->priv_lock);
 759
 760         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 761                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 762                 list_del(&unlink->list);
 763                 kfree(unlink);
 764         }
 765
 766         while (!list_empty(&vdev->unlink_rx)) {
 767                 struct urb *urb;
 768
 769                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 770                         list);
 771
 772                 /* give back URB of unanswered unlink request */
 773                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 774
 775                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 776                 if (!urb) {
 777                         pr_info("the urb (seqnum %lu) was already given back\n",
 778                                 unlink->unlink_seqnum);
 779                         list_del(&unlink->list);
 780                         kfree(unlink);
 781                         continue;
 782                 }
 783
 784                 urb->status = -ENODEV;
 785
 786                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 787
 788                 list_del(&unlink->list);
 789
 790                 spin_unlock(&vdev->priv_lock);
 791                 spin_unlock_irqrestore(&vhci->lock, flags);
 792
 793                 usb_hcd_giveback_urb(hcd, urb, urb->status);
 794
 795                 spin_lock_irqsave(&vhci->lock, flags);
 796                 spin_lock(&vdev->priv_lock);
 797
 798                 kfree(unlink);
 799         }
 800
 801         spin_unlock(&vdev->priv_lock);
 802         spin_unlock_irqrestore(&vhci->lock, flags);
 803 }
 804
 805 /*
 806  * The important thing is that only one context begins cleanup.
 807  * This is why error handling and cleanup become simple.
 808  * We do not want to consider race condition as possible.
 809  */
 810 static void vhci_shutdown_connection(struct usbip_device *ud)
 811 {
 812         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 813
 814         /* need this? see stub_dev.c */
 815         if (ud->tcp_socket) {
 816                 pr_debug("shutdown tcp_socket\n");
 817                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 818         }
 819
 820         /* kill threads related to this sdev */
 821         if (vdev->ud.tcp_rx) {
 822                 kthread_stop_put(vdev->ud.tcp_rx);
 823                 vdev->ud.tcp_rx = NULL;
 824         }
 825         if (vdev->ud.tcp_tx) {
 826                 kthread_stop_put(vdev->ud.tcp_tx);
 827                 vdev->ud.tcp_tx = NULL;
 828         }
 829         pr_info("stop threads\n");
 830
 831         /* active connection is closed */
 832         if (vdev->ud.tcp_socket) {
 833                 sockfd_put(vdev->ud.tcp_socket);
 834                 vdev->ud.tcp_socket = NULL;
 835                 vdev->ud.sockfd = -1;
 836         }
 837         pr_info("release socket\n");
 838
 839         vhci_device_unlink_cleanup(vdev);
 840
 841         /*
 842          * rh_port_disconnect() is a trigger of ...
 843          *   usb_disable_device():
 844          *      disable all the endpoints for a USB device.
 845          *   usb_disable_endpoint():
 846          *      disable endpoints. pending urbs are unlinked(dequeued).
 847          *
 848          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 849          * detached device should release used urbs in a cleanup function (i.e.
 850          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 851          * pushed urbs and their private data in this function.
 852          *
 853          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 854          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 855          * gives back pushed urbs and frees their private data by request of
 856          * the cleanup function of a USB driver. When unlinking a urb with an
 857          * active connection, vhci_dequeue() does not give back the urb which
 858          * is actually given back by vhci_rx after receiving its return pdu.
 859          *
 860          */
 861         rh_port_disconnect(vdev);
 862
 863         pr_info("disconnect device\n");
 864 }
 865
 866
 867 static void vhci_device_reset(struct usbip_device *ud)
 868 {
 869         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 870         unsigned long flags;
 871
 872         spin_lock_irqsave(&ud->lock, flags);
 873
 874         vdev->speed  = 0;
 875         vdev->devid  = 0;
 876
 877         usb_put_dev(vdev->udev);
 878         vdev->udev = NULL;
 879
 880         if (ud->tcp_socket) {
 881                 sockfd_put(ud->tcp_socket);
 882                 ud->tcp_socket = NULL;
 883                 ud->sockfd = -1;
 884         }
 885         ud->status = VDEV_ST_NULL;
 886
 887         spin_unlock_irqrestore(&ud->lock, flags);
 888 }
 889
 890 static void vhci_device_unusable(struct usbip_device *ud)
 891 {
 892         unsigned long flags;
 893
 894         spin_lock_irqsave(&ud->lock, flags);
 895         ud->status = VDEV_ST_ERROR;
 896         spin_unlock_irqrestore(&ud->lock, flags);
 897 }
 898
 899 static void vhci_device_init(struct vhci_device *vdev)
 900 {
 901         memset(vdev, 0, sizeof(struct vhci_device));
 902
 903         vdev->ud.side   = USBIP_VHCI;
 904         vdev->ud.status = VDEV_ST_NULL;
 905         spin_lock_init(&vdev->ud.lock);
 906
 907         INIT_LIST_HEAD(&vdev->priv_rx);
 908         INIT_LIST_HEAD(&vdev->priv_tx);
 909         INIT_LIST_HEAD(&vdev->unlink_tx);
 910         INIT_LIST_HEAD(&vdev->unlink_rx);
 911         spin_lock_init(&vdev->priv_lock);
 912
 913         init_waitqueue_head(&vdev->waitq_tx);
 914
 915         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 916         vdev->ud.eh_ops.reset = vhci_device_reset;
 917         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 918
 919         usbip_start_eh(&vdev->ud);
 920 }
 921
 922 static int hcd_name_to_id(const char *name)
 923 {
 924         char *c;
 925         long val;
 926         int ret;
 927
 928         c = strchr(name, '.');
 929         if (c == NULL)
 930                 return 0;
 931
 932         ret = kstrtol(c+1, 10, &val);
 933         if (ret < 0)
 934                 return ret;
 935
 936         return val;
 937 }
 938
 939 static int vhci_start(struct usb_hcd *hcd)
 940 {
 941         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 942         int id, rhport;
 943         int err = 0;
 944
 945         usbip_dbg_vhci_hc("enter vhci_start\n");
 946
 947         /* initialize private data of usb_hcd */
 948
 949         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 950                 struct vhci_device *vdev = &vhci->vdev[rhport];
 951
 952                 vhci_device_init(vdev);
 953                 vdev->rhport = rhport;
 954         }
 955
 956         atomic_set(&vhci->seqnum, 0);
 957         spin_lock_init(&vhci->lock);
 958
 959         hcd->power_budget = 0; /* no limit */
 960         hcd->uses_new_polling = 1;
 961
 962         id = hcd_name_to_id(hcd_name(hcd));
 963         if (id < 0) {
 964                 pr_err("invalid vhci name %s\n", hcd_name(hcd));
 965                 return -EINVAL;
 966         }
 967
 968         /* vhci_hcd is now ready to be controlled through sysfs */
 969         if (id == 0) {
 970                 err = vhci_init_attr_group();
 971                 if (err) {
 972                         pr_err("init attr group\n");
 973                         return err;
 974                 }
 975                 err = sysfs_create_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
 976                 if (err) {
 977                         pr_err("create sysfs files\n");
 978                         vhci_finish_attr_group();
 979                         return err;
 980                 }
 981                 pr_info("created sysfs %s\n", hcd_name(hcd));
 982         }
 983
 984         return 0;
 985 }
 986
 987 static void vhci_stop(struct usb_hcd *hcd)
 988 {
 989         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 990         int id, rhport;
 991
 992         usbip_dbg_vhci_hc("stop VHCI controller\n");
 993
 994         /* 1. remove the userland interface of vhci_hcd */
 995         id = hcd_name_to_id(hcd_name(hcd));
 996         if (id == 0) {
 997                 sysfs_remove_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
 998                 vhci_finish_attr_group();
 999         }
1000
1001         /* 2. shutdown all the ports of vhci_hcd */
1002         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
1003                 struct vhci_device *vdev = &vhci->vdev[rhport];
1004
1005                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
1006                 usbip_stop_eh(&vdev->ud);
1007         }
1008 }
1009
1010 static int vhci_get_frame_number(struct usb_hcd *hcd)
1011 {
1012         dev_err_ratelimited(&hcd->self.root_hub->dev, "Not yet implemented\n");
1013         return 0;
1014 }
1015
1016 #ifdef CONFIG_PM
1017
1018 /* FIXME: suspend/resume */
1019 static int vhci_bus_suspend(struct usb_hcd *hcd)
1020 {
1021         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1022         unsigned long flags;
1023
1024         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1025
1026         spin_lock_irqsave(&vhci->lock, flags);
1027         hcd->state = HC_STATE_SUSPENDED;
1028         spin_unlock_irqrestore(&vhci->lock, flags);
1029
1030         return 0;
1031 }
1032
1033 static int vhci_bus_resume(struct usb_hcd *hcd)
1034 {
1035         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1036         int rc = 0;
1037         unsigned long flags;
1038
1039         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1040
1041         spin_lock_irqsave(&vhci->lock, flags);
1042         if (!HCD_HW_ACCESSIBLE(hcd))
1043                 rc = -ESHUTDOWN;
1044         else
1045                 hcd->state = HC_STATE_RUNNING;
1046         spin_unlock_irqrestore(&vhci->lock, flags);
1047
1048         return rc;
1049 }
1050
1051 #else
1052
1053 #define vhci_bus_suspend      NULL
1054 #define vhci_bus_resume       NULL
1055 #endif
1056
1057 static struct hc_driver vhci_hc_driver = {
1058         .description    = driver_name,
1059         .product_desc   = driver_desc,
1060         .hcd_priv_size  = sizeof(struct vhci_hcd),
1061
1062         .flags          = HCD_USB2,
1063
1064         .start          = vhci_start,
1065         .stop           = vhci_stop,
1066
1067         .urb_enqueue    = vhci_urb_enqueue,
1068         .urb_dequeue    = vhci_urb_dequeue,
1069
1070         .get_frame_number = vhci_get_frame_number,
1071
1072         .hub_status_data = vhci_hub_status,
1073         .hub_control    = vhci_hub_control,
1074         .bus_suspend    = vhci_bus_suspend,
1075         .bus_resume     = vhci_bus_resume,
1076 };
1077
1078 static int vhci_hcd_probe(struct platform_device *pdev)
1079 {
1080         struct usb_hcd          *hcd;
1081         int                     ret;
1082
1083         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1084
1085         /*
1086          * Allocate and initialize hcd.
1087          * Our private data is also allocated automatically.
1088          */
1089         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1090         if (!hcd) {
1091                 pr_err("create hcd failed\n");
1092                 return -ENOMEM;
1093         }
1094         hcd->has_tt = 1;
1095
1096         /*
1097          * Finish generic HCD structure initialization and register.
1098          * Call the driver's reset() and start() routines.
1099          */
1100         ret = usb_add_hcd(hcd, 0, 0);
1101         if (ret != 0) {
1102                 pr_err("usb_add_hcd failed %d\n", ret);
1103                 usb_put_hcd(hcd);
1104                 return ret;
1105         }
1106
1107         usbip_dbg_vhci_hc("bye\n");
1108         return 0;
1109 }
1110
1111 static int vhci_hcd_remove(struct platform_device *pdev)
1112 {
1113         struct usb_hcd  *hcd;
1114
1115         hcd = platform_get_drvdata(pdev);
1116         if (!hcd)
1117                 return 0;
1118
1119         /*
1120          * Disconnects the root hub,
1121          * then reverses the effects of usb_add_hcd(),
1122          * invoking the HCD's stop() methods.
1123          */
1124         usb_remove_hcd(hcd);
1125         usb_put_hcd(hcd);
1126
1127         return 0;
1128 }
1129
1130 #ifdef CONFIG_PM
1131
1132 /* what should happen for USB/IP under suspend/resume? */
1133 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1134 {
1135         struct usb_hcd *hcd;
1136         struct vhci_hcd *vhci;
1137         int rhport;
1138         int connected = 0;
1139         int ret = 0;
1140         unsigned long flags;
1141
1142         hcd = platform_get_drvdata(pdev);
1143         if (!hcd)
1144                 return 0;
1145         vhci = hcd_to_vhci(hcd);
1146
1147         spin_lock_irqsave(&vhci->lock, flags);
1148
1149         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++)
1150                 if (vhci->port_status[rhport] & USB_PORT_STAT_CONNECTION)
1151                         connected += 1;
1152
1153         spin_unlock_irqrestore(&vhci->lock, flags);
1154
1155         if (connected > 0) {
1156                 dev_info(&pdev->dev,
1157                          "We have %d active connection%s. Do not suspend.\n",
1158                          connected, (connected == 1 ? "" : "s"));
1159                 ret =  -EBUSY;
1160         } else {
1161                 dev_info(&pdev->dev, "suspend vhci_hcd");
1162                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1163         }
1164
1165         return ret;
1166 }
1167
1168 static int vhci_hcd_resume(struct platform_device *pdev)
1169 {
1170         struct usb_hcd *hcd;
1171
1172         dev_dbg(&pdev->dev, "%s\n", __func__);
1173
1174         hcd = platform_get_drvdata(pdev);
1175         if (!hcd)
1176                 return 0;
1177         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1178         usb_hcd_poll_rh_status(hcd);
1179
1180         return 0;
1181 }
1182
1183 #else
1184
1185 #define vhci_hcd_suspend        NULL
1186 #define vhci_hcd_resume         NULL
1187
1188 #endif
1189
1190 static struct platform_driver vhci_driver = {
1191         .probe  = vhci_hcd_probe,
1192         .remove = vhci_hcd_remove,
1193         .suspend = vhci_hcd_suspend,
1194         .resume = vhci_hcd_resume,
1195         .driver = {
1196                 .name = driver_name,
1197         },
1198 };
1199
1200 static int add_platform_device(int id)
1201 {
1202         struct platform_device *pdev;
1203         int dev_nr;
1204
1205         if (id == 0)
1206                 dev_nr = -1;
1207         else
1208                 dev_nr = id;
1209
1210         pdev = platform_device_register_simple(driver_name, dev_nr, NULL, 0);
1211         if (IS_ERR(pdev))
1212                 return PTR_ERR(pdev);
1213
1214         *(vhci_pdevs + id) = pdev;
1215         return 0;
1216 }
1217
1218 static void del_platform_devices(void)
1219 {
1220         struct platform_device *pdev;
1221         int i;
1222
1223         for (i = 0; i < vhci_num_controllers; i++) {
1224                 pdev = *(vhci_pdevs + i);
1225                 if (pdev != NULL)
1226                         platform_device_unregister(pdev);
1227                 *(vhci_pdevs + i) = NULL;
1228         }
1229         sysfs_remove_link(&platform_bus.kobj, driver_name);
1230 }
1231
1232 static int __init vhci_hcd_init(void)
1233 {
1234         int i, ret;
1235
1236         if (usb_disabled())
1237                 return -ENODEV;
1238
1239         if (vhci_num_controllers < 1)
1240                 vhci_num_controllers = 1;
1241
1242         vhci_pdevs = kcalloc(vhci_num_controllers, sizeof(void *), GFP_KERNEL);
1243         if (vhci_pdevs == NULL)
1244                 return -ENOMEM;
1245
1246         ret = platform_driver_register(&vhci_driver);
1247         if (ret)
1248                 goto err_driver_register;
1249
1250         for (i = 0; i < vhci_num_controllers; i++) {
1251                 ret = add_platform_device(i);
1252                 if (ret)
1253                         goto err_platform_device_register;
1254         }
1255
1256         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1257         return ret;
1258
1259 err_platform_device_register:
1260         del_platform_devices();
1261         platform_driver_unregister(&vhci_driver);
1262 err_driver_register:
1263         kfree(vhci_pdevs);
1264         return ret;
1265 }
1266
1267 static void __exit vhci_hcd_exit(void)
1268 {
1269         del_platform_devices();
1270         platform_driver_unregister(&vhci_driver);
1271         kfree(vhci_pdevs);
1272 }
1273
1274 module_init(vhci_hcd_init);
1275 module_exit(vhci_hcd_exit);
1276
1277 MODULE_AUTHOR(DRIVER_AUTHOR);
1278 MODULE_DESCRIPTION(DRIVER_DESC);
1279 MODULE_LICENSE("GPL");
1280 MODULE_VERSION(USBIP_VERSION);