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                         break;
 317                 default:
 318                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 319                                           wValue);
 320                         dum->port_status[rhport] &= ~(1 << wValue);
 321                         break;
 322                 }
 323                 break;
 324         case GetHubDescriptor:
 325                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 326                 hub_descriptor((struct usb_hub_descriptor *) buf);
 327                 break;
 328         case GetHubStatus:
 329                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 330                 *(__le32 *) buf = cpu_to_le32(0);
 331                 break;
 332         case GetPortStatus:
 333                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 334                 if (wIndex > VHCI_HC_PORTS || wIndex < 1) {
 335                         pr_err("invalid port number %d\n", wIndex);
 336                         retval = -EPIPE;
 337                 }
 338
 339                 /* we do not care about resume. */
 340
 341                 /* whoever resets or resumes must GetPortStatus to
 342                  * complete it!!
 343                  */
 344                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 345                         dum->port_status[rhport] |=
 346                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 347                         dum->port_status[rhport] &=
 348                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 349                         dum->resuming = 0;
 350                         dum->re_timeout = 0;
 351                 }
 352
 353                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 354                     0 && time_after(jiffies, dum->re_timeout)) {
 355                         dum->port_status[rhport] |=
 356                                 (1 << USB_PORT_FEAT_C_RESET);
 357                         dum->port_status[rhport] &=
 358                                 ~(1 << USB_PORT_FEAT_RESET);
 359                         dum->re_timeout = 0;
 360
 361                         if (dum->vdev[rhport].ud.status ==
 362                             VDEV_ST_NOTASSIGNED) {
 363                                 usbip_dbg_vhci_rh(
 364                                         " enable rhport %d (status %u)\n",
 365                                         rhport,
 366                                         dum->vdev[rhport].ud.status);
 367                                 dum->port_status[rhport] |=
 368                                         USB_PORT_STAT_ENABLE;
 369                         }
 370                 }
 371                 ((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 372                 ((__le16 *) buf)[1] =
 373                         cpu_to_le16(dum->port_status[rhport] >> 16);
 374
 375                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 376                                   ((u16 *)buf)[1]);
 377                 break;
 378         case SetHubFeature:
 379                 usbip_dbg_vhci_rh(" SetHubFeature\n");
 380                 retval = -EPIPE;
 381                 break;
 382         case SetPortFeature:
 383                 switch (wValue) {
 384                 case USB_PORT_FEAT_SUSPEND:
 385                         usbip_dbg_vhci_rh(
 386                                 " SetPortFeature: USB_PORT_FEAT_SUSPEND\n");
 387                         break;
 388                 case USB_PORT_FEAT_RESET:
 389                         usbip_dbg_vhci_rh(
 390                                 " SetPortFeature: USB_PORT_FEAT_RESET\n");
 391                         /* if it's already running, disconnect first */
 392                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 393                                 dum->port_status[rhport] &=
 394                                         ~(USB_PORT_STAT_ENABLE |
 395                                           USB_PORT_STAT_LOW_SPEED |
 396                                           USB_PORT_STAT_HIGH_SPEED);
 397                                 /* FIXME test that code path! */
 398                         }
 399                         /* 50msec reset signaling */
 400                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
 401
 402                         /* FALLTHROUGH */
 403                 default:
 404                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 405                                           wValue);
 406                         dum->port_status[rhport] |= (1 << wValue);
 407                         break;
 408                 }
 409                 break;
 410
 411         default:
 412                 pr_err("default: no such request\n");
 413
 414                 /* "protocol stall" on error */
 415                 retval = -EPIPE;
 416         }
 417
 418         if (usbip_dbg_flag_vhci_rh) {
 419                 pr_debug("port %d\n", rhport);
 420                 /* Only dump valid port status */
 421                 if (rhport >= 0) {
 422                         dump_port_status_diff(prev_port_status[rhport],
 423                                               dum->port_status[rhport]);
 424                 }
 425         }
 426         usbip_dbg_vhci_rh(" bye\n");
 427
 428         spin_unlock_irqrestore(&dum->lock, flags);
 429
 430         return retval;
 431 }
 432
 433 static void vhci_tx_urb(struct urb *urb, struct vhci_device *vdev)
 434 {
 435         struct vhci_priv *priv;
 436         struct vhci_hcd *vhci;
 437         unsigned long flags;
 438
 439         if (!vdev) {
 440                 pr_err("could not get virtual device");
 441                 return;
 442         }
 443         vhci = vdev_to_vhci(vdev);
 444
 445         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 446         if (!priv) {
 447                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 448                 return;
 449         }
 450
 451         spin_lock_irqsave(&vdev->priv_lock, flags);
 452
 453         priv->seqnum = atomic_inc_return(&vhci->seqnum);
 454         if (priv->seqnum == 0xffff)
 455                 dev_info(&urb->dev->dev, "seqnum max\n");
 456
 457         priv->vdev = vdev;
 458         priv->urb = urb;
 459
 460         urb->hcpriv = (void *) priv;
 461
 462         list_add_tail(&priv->list, &vdev->priv_tx);
 463
 464         wake_up(&vdev->waitq_tx);
 465         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 466 }
 467
 468 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 469                             gfp_t mem_flags)
 470 {
 471         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 472         struct device *dev = &urb->dev->dev;
 473         u8 portnum = urb->dev->portnum;
 474         int ret = 0;
 475         struct vhci_device *vdev;
 476         unsigned long flags;
 477
 478         usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
 479                           hcd, urb, mem_flags);
 480
 481         if (portnum > VHCI_HC_PORTS) {
 482                 pr_err("invalid port number %d\n", portnum);
 483                 return -ENODEV;
 484         }
 485         vdev = &vhci->vdev[portnum-1];
 486
 487         /* patch to usb_sg_init() is in 2.5.60 */
 488         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 489
 490         spin_lock_irqsave(&vhci->lock, flags);
 491
 492         if (urb->status != -EINPROGRESS) {
 493                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 494                 spin_unlock_irqrestore(&vhci->lock, flags);
 495                 return urb->status;
 496         }
 497
 498         /* refuse enqueue for dead connection */
 499         spin_lock(&vdev->ud.lock);
 500         if (vdev->ud.status == VDEV_ST_NULL ||
 501             vdev->ud.status == VDEV_ST_ERROR) {
 502                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 503                 spin_unlock(&vdev->ud.lock);
 504                 spin_unlock_irqrestore(&vhci->lock, flags);
 505                 return -ENODEV;
 506         }
 507         spin_unlock(&vdev->ud.lock);
 508
 509         ret = usb_hcd_link_urb_to_ep(hcd, urb);
 510         if (ret)
 511                 goto no_need_unlink;
 512
 513         /*
 514          * The enumeration process is as follows;
 515          *
 516          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 517          *     to get max packet length of default pipe
 518          *
 519          *  2. Set_Address request to DevAddr(0) EndPoint(0)
 520          *
 521          */
 522         if (usb_pipedevice(urb->pipe) == 0) {
 523                 __u8 type = usb_pipetype(urb->pipe);
 524                 struct usb_ctrlrequest *ctrlreq =
 525                         (struct usb_ctrlrequest *) urb->setup_packet;
 526
 527                 if (type != PIPE_CONTROL || !ctrlreq) {
 528                         dev_err(dev, "invalid request to devnum 0\n");
 529                         ret = -EINVAL;
 530                         goto no_need_xmit;
 531                 }
 532
 533                 switch (ctrlreq->bRequest) {
 534                 case USB_REQ_SET_ADDRESS:
 535                         /* set_address may come when a device is reset */
 536                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
 537                                  ctrlreq->wValue, vdev->rhport);
 538
 539                         usb_put_dev(vdev->udev);
 540                         vdev->udev = usb_get_dev(urb->dev);
 541
 542                         spin_lock(&vdev->ud.lock);
 543                         vdev->ud.status = VDEV_ST_USED;
 544                         spin_unlock(&vdev->ud.lock);
 545
 546                         if (urb->status == -EINPROGRESS) {
 547                                 /* This request is successfully completed. */
 548                                 /* If not -EINPROGRESS, possibly unlinked. */
 549                                 urb->status = 0;
 550                         }
 551
 552                         goto no_need_xmit;
 553
 554                 case USB_REQ_GET_DESCRIPTOR:
 555                         if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
 556                                 usbip_dbg_vhci_hc(
 557                                         "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
 558
 559                         usb_put_dev(vdev->udev);
 560                         vdev->udev = usb_get_dev(urb->dev);
 561                         goto out;
 562
 563                 default:
 564                         /* NOT REACHED */
 565                         dev_err(dev,
 566                                 "invalid request to devnum 0 bRequest %u, wValue %u\n",
 567                                 ctrlreq->bRequest,
 568                                 ctrlreq->wValue);
 569                         ret =  -EINVAL;
 570                         goto no_need_xmit;
 571                 }
 572
 573         }
 574
 575 out:
 576         vhci_tx_urb(urb, vdev);
 577         spin_unlock_irqrestore(&vhci->lock, flags);
 578
 579         return 0;
 580
 581 no_need_xmit:
 582         usb_hcd_unlink_urb_from_ep(hcd, urb);
 583 no_need_unlink:
 584         spin_unlock_irqrestore(&vhci->lock, flags);
 585         if (!ret)
 586                 usb_hcd_giveback_urb(hcd, urb, urb->status);
 587         return ret;
 588 }
 589
 590 /*
 591  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 592  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 593  * back its urb. For the driver unlinking the urb, the content of the urb is
 594  * not important, but the calling to its completion handler is important; the
 595  * completion of unlinking is notified by the completion handler.
 596  *
 597  *
 598  * CLIENT SIDE
 599  *
 600  * - When vhci_hcd receives RET_SUBMIT,
 601  *
 602  *      - case 1a). the urb of the pdu is not unlinking.
 603  *              - normal case
 604  *              => just give back the urb
 605  *
 606  *      - case 1b). the urb of the pdu is unlinking.
 607  *              - usbip.ko will return a reply of the unlinking request.
 608  *              => give back the urb now and go to case 2b).
 609  *
 610  * - When vhci_hcd receives RET_UNLINK,
 611  *
 612  *      - case 2a). a submit request is still pending in vhci_hcd.
 613  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 614  *                completed there.
 615  *              => free a pending submit request
 616  *              => notify unlink completeness by giving back the urb
 617  *
 618  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 619  *              - urb was already given back to the core driver.
 620  *              => do not give back the urb
 621  *
 622  *
 623  * SERVER SIDE
 624  *
 625  * - When usbip receives CMD_UNLINK,
 626  *
 627  *      - case 3a). the urb of the unlink request is now in submission.
 628  *              => do usb_unlink_urb().
 629  *              => after the unlink is completed, send RET_UNLINK.
 630  *
 631  *      - case 3b). the urb of the unlink request is not in submission.
 632  *              - may be already completed or never be received
 633  *              => send RET_UNLINK
 634  *
 635  */
 636 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 637 {
 638         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 639         struct vhci_priv *priv;
 640         struct vhci_device *vdev;
 641         unsigned long flags;
 642
 643         pr_info("dequeue a urb %p\n", urb);
 644
 645         spin_lock_irqsave(&vhci->lock, flags);
 646
 647         priv = urb->hcpriv;
 648         if (!priv) {
 649                 /* URB was never linked! or will be soon given back by
 650                  * vhci_rx. */
 651                 spin_unlock_irqrestore(&vhci->lock, flags);
 652                 return -EIDRM;
 653         }
 654
 655         {
 656                 int ret = 0;
 657
 658                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 659                 if (ret) {
 660                         spin_unlock_irqrestore(&vhci->lock, flags);
 661                         return ret;
 662                 }
 663         }
 664
 665          /* send unlink request here? */
 666         vdev = priv->vdev;
 667
 668         if (!vdev->ud.tcp_socket) {
 669                 /* tcp connection is closed */
 670                 spin_lock(&vdev->priv_lock);
 671
 672                 pr_info("device %p seems to be disconnected\n", vdev);
 673                 list_del(&priv->list);
 674                 kfree(priv);
 675                 urb->hcpriv = NULL;
 676
 677                 spin_unlock(&vdev->priv_lock);
 678
 679                 /*
 680                  * If tcp connection is alive, we have sent CMD_UNLINK.
 681                  * vhci_rx will receive RET_UNLINK and give back the URB.
 682                  * Otherwise, we give back it here.
 683                  */
 684                 pr_info("gives back urb %p\n", urb);
 685
 686                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 687
 688                 spin_unlock_irqrestore(&vhci->lock, flags);
 689                 usb_hcd_giveback_urb(vhci_to_hcd(vhci), urb, urb->status);
 690                 spin_lock_irqsave(&vhci->lock, flags);
 691
 692         } else {
 693                 /* tcp connection is alive */
 694                 struct vhci_unlink *unlink;
 695
 696                 spin_lock(&vdev->priv_lock);
 697
 698                 /* setup CMD_UNLINK pdu */
 699                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 700                 if (!unlink) {
 701                         spin_unlock(&vdev->priv_lock);
 702                         spin_unlock_irqrestore(&vhci->lock, flags);
 703                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 704                         return -ENOMEM;
 705                 }
 706
 707                 unlink->seqnum = atomic_inc_return(&vhci->seqnum);
 708                 if (unlink->seqnum == 0xffff)
 709                         pr_info("seqnum max\n");
 710
 711                 unlink->unlink_seqnum = priv->seqnum;
 712
 713                 pr_info("device %p seems to be still connected\n", vdev);
 714
 715                 /* send cmd_unlink and try to cancel the pending URB in the
 716                  * peer */
 717                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 718                 wake_up(&vdev->waitq_tx);
 719
 720                 spin_unlock(&vdev->priv_lock);
 721         }
 722
 723         spin_unlock_irqrestore(&vhci->lock, flags);
 724
 725         usbip_dbg_vhci_hc("leave\n");
 726         return 0;
 727 }
 728
 729 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 730 {
 731         struct vhci_hcd *vhci = vdev_to_vhci(vdev);
 732         struct usb_hcd *hcd = vhci_to_hcd(vhci);
 733         struct vhci_unlink *unlink, *tmp;
 734         unsigned long flags;
 735
 736         spin_lock_irqsave(&vhci->lock, flags);
 737         spin_lock(&vdev->priv_lock);
 738
 739         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 740                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 741                 list_del(&unlink->list);
 742                 kfree(unlink);
 743         }
 744
 745         while (!list_empty(&vdev->unlink_rx)) {
 746                 struct urb *urb;
 747
 748                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 749                         list);
 750
 751                 /* give back URB of unanswered unlink request */
 752                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 753
 754                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 755                 if (!urb) {
 756                         pr_info("the urb (seqnum %lu) was already given back\n",
 757                                 unlink->unlink_seqnum);
 758                         list_del(&unlink->list);
 759                         kfree(unlink);
 760                         continue;
 761                 }
 762
 763                 urb->status = -ENODEV;
 764
 765                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 766
 767                 list_del(&unlink->list);
 768
 769                 spin_unlock(&vdev->priv_lock);
 770                 spin_unlock_irqrestore(&vhci->lock, flags);
 771
 772                 usb_hcd_giveback_urb(hcd, urb, urb->status);
 773
 774                 spin_lock_irqsave(&vhci->lock, flags);
 775                 spin_lock(&vdev->priv_lock);
 776
 777                 kfree(unlink);
 778         }
 779
 780         spin_unlock(&vdev->priv_lock);
 781         spin_unlock_irqrestore(&vhci->lock, flags);
 782 }
 783
 784 /*
 785  * The important thing is that only one context begins cleanup.
 786  * This is why error handling and cleanup become simple.
 787  * We do not want to consider race condition as possible.
 788  */
 789 static void vhci_shutdown_connection(struct usbip_device *ud)
 790 {
 791         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 792
 793         /* need this? see stub_dev.c */
 794         if (ud->tcp_socket) {
 795                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 796                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 797         }
 798
 799         /* kill threads related to this sdev */
 800         if (vdev->ud.tcp_rx) {
 801                 kthread_stop_put(vdev->ud.tcp_rx);
 802                 vdev->ud.tcp_rx = NULL;
 803         }
 804         if (vdev->ud.tcp_tx) {
 805                 kthread_stop_put(vdev->ud.tcp_tx);
 806                 vdev->ud.tcp_tx = NULL;
 807         }
 808         pr_info("stop threads\n");
 809
 810         /* active connection is closed */
 811         if (vdev->ud.tcp_socket) {
 812                 sockfd_put(vdev->ud.tcp_socket);
 813                 vdev->ud.tcp_socket = NULL;
 814         }
 815         pr_info("release socket\n");
 816
 817         vhci_device_unlink_cleanup(vdev);
 818
 819         /*
 820          * rh_port_disconnect() is a trigger of ...
 821          *   usb_disable_device():
 822          *      disable all the endpoints for a USB device.
 823          *   usb_disable_endpoint():
 824          *      disable endpoints. pending urbs are unlinked(dequeued).
 825          *
 826          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 827          * detached device should release used urbs in a cleanup function (i.e.
 828          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 829          * pushed urbs and their private data in this function.
 830          *
 831          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 832          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 833          * gives back pushed urbs and frees their private data by request of
 834          * the cleanup function of a USB driver. When unlinking a urb with an
 835          * active connection, vhci_dequeue() does not give back the urb which
 836          * is actually given back by vhci_rx after receiving its return pdu.
 837          *
 838          */
 839         rh_port_disconnect(vdev);
 840
 841         pr_info("disconnect device\n");
 842 }
 843
 844
 845 static void vhci_device_reset(struct usbip_device *ud)
 846 {
 847         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 848         unsigned long flags;
 849
 850         spin_lock_irqsave(&ud->lock, flags);
 851
 852         vdev->speed  = 0;
 853         vdev->devid  = 0;
 854
 855         usb_put_dev(vdev->udev);
 856         vdev->udev = NULL;
 857
 858         if (ud->tcp_socket) {
 859                 sockfd_put(ud->tcp_socket);
 860                 ud->tcp_socket = NULL;
 861         }
 862         ud->status = VDEV_ST_NULL;
 863
 864         spin_unlock_irqrestore(&ud->lock, flags);
 865 }
 866
 867 static void vhci_device_unusable(struct usbip_device *ud)
 868 {
 869         unsigned long flags;
 870
 871         spin_lock_irqsave(&ud->lock, flags);
 872         ud->status = VDEV_ST_ERROR;
 873         spin_unlock_irqrestore(&ud->lock, flags);
 874 }
 875
 876 static void vhci_device_init(struct vhci_device *vdev)
 877 {
 878         memset(vdev, 0, sizeof(struct vhci_device));
 879
 880         vdev->ud.side   = USBIP_VHCI;
 881         vdev->ud.status = VDEV_ST_NULL;
 882         spin_lock_init(&vdev->ud.lock);
 883
 884         INIT_LIST_HEAD(&vdev->priv_rx);
 885         INIT_LIST_HEAD(&vdev->priv_tx);
 886         INIT_LIST_HEAD(&vdev->unlink_tx);
 887         INIT_LIST_HEAD(&vdev->unlink_rx);
 888         spin_lock_init(&vdev->priv_lock);
 889
 890         init_waitqueue_head(&vdev->waitq_tx);
 891
 892         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 893         vdev->ud.eh_ops.reset = vhci_device_reset;
 894         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 895
 896         usbip_start_eh(&vdev->ud);
 897 }
 898
 899 static int hcd_name_to_id(const char *name)
 900 {
 901         char *c;
 902         long val;
 903         int ret;
 904
 905         c = strchr(name, '.');
 906         if (c == NULL)
 907                 return 0;
 908
 909         ret = kstrtol(c+1, 10, &val);
 910         if (ret < 0)
 911                 return ret;
 912
 913         return val;
 914 }
 915
 916 static int vhci_start(struct usb_hcd *hcd)
 917 {
 918         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 919         int id, rhport;
 920         int err = 0;
 921
 922         usbip_dbg_vhci_hc("enter vhci_start\n");
 923
 924         /* initialize private data of usb_hcd */
 925
 926         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 927                 struct vhci_device *vdev = &vhci->vdev[rhport];
 928
 929                 vhci_device_init(vdev);
 930                 vdev->rhport = rhport;
 931         }
 932
 933         atomic_set(&vhci->seqnum, 0);
 934         spin_lock_init(&vhci->lock);
 935
 936         hcd->power_budget = 0; /* no limit */
 937         hcd->uses_new_polling = 1;
 938
 939         id = hcd_name_to_id(hcd_name(hcd));
 940         if (id < 0) {
 941                 pr_err("invalid vhci name %s\n", hcd_name(hcd));
 942                 return -EINVAL;
 943         }
 944
 945         /* vhci_hcd is now ready to be controlled through sysfs */
 946         if (id == 0) {
 947                 err = vhci_init_attr_group();
 948                 if (err) {
 949                         pr_err("init attr group\n");
 950                         return err;
 951                 }
 952                 err = sysfs_create_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
 953                 if (err) {
 954                         pr_err("create sysfs files\n");
 955                         vhci_finish_attr_group();
 956                         return err;
 957                 }
 958                 pr_info("created sysfs %s\n", hcd_name(hcd));
 959         }
 960
 961         return 0;
 962 }
 963
 964 static void vhci_stop(struct usb_hcd *hcd)
 965 {
 966         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 967         int id, rhport;
 968
 969         usbip_dbg_vhci_hc("stop VHCI controller\n");
 970
 971         /* 1. remove the userland interface of vhci_hcd */
 972         id = hcd_name_to_id(hcd_name(hcd));
 973         if (id == 0) {
 974                 sysfs_remove_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
 975                 vhci_finish_attr_group();
 976         }
 977
 978         /* 2. shutdown all the ports of vhci_hcd */
 979         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 980                 struct vhci_device *vdev = &vhci->vdev[rhport];
 981
 982                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
 983                 usbip_stop_eh(&vdev->ud);
 984         }
 985 }
 986
 987 static int vhci_get_frame_number(struct usb_hcd *hcd)
 988 {
 989         dev_err_ratelimited(&hcd->self.root_hub->dev, "Not yet implemented\n");
 990         return 0;
 991 }
 992
 993 #ifdef CONFIG_PM
 994
 995 /* FIXME: suspend/resume */
 996 static int vhci_bus_suspend(struct usb_hcd *hcd)
 997 {
 998         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 999         unsigned long flags;
1000
1001         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1002
1003         spin_lock_irqsave(&vhci->lock, flags);
1004         hcd->state = HC_STATE_SUSPENDED;
1005         spin_unlock_irqrestore(&vhci->lock, flags);
1006
1007         return 0;
1008 }
1009
1010 static int vhci_bus_resume(struct usb_hcd *hcd)
1011 {
1012         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1013         int rc = 0;
1014         unsigned long flags;
1015
1016         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1017
1018         spin_lock_irqsave(&vhci->lock, flags);
1019         if (!HCD_HW_ACCESSIBLE(hcd))
1020                 rc = -ESHUTDOWN;
1021         else
1022                 hcd->state = HC_STATE_RUNNING;
1023         spin_unlock_irqrestore(&vhci->lock, flags);
1024
1025         return rc;
1026 }
1027
1028 #else
1029
1030 #define vhci_bus_suspend      NULL
1031 #define vhci_bus_resume       NULL
1032 #endif
1033
1034 static struct hc_driver vhci_hc_driver = {
1035         .description    = driver_name,
1036         .product_desc   = driver_desc,
1037         .hcd_priv_size  = sizeof(struct vhci_hcd),
1038
1039         .flags          = HCD_USB2,
1040
1041         .start          = vhci_start,
1042         .stop           = vhci_stop,
1043
1044         .urb_enqueue    = vhci_urb_enqueue,
1045         .urb_dequeue    = vhci_urb_dequeue,
1046
1047         .get_frame_number = vhci_get_frame_number,
1048
1049         .hub_status_data = vhci_hub_status,
1050         .hub_control    = vhci_hub_control,
1051         .bus_suspend    = vhci_bus_suspend,
1052         .bus_resume     = vhci_bus_resume,
1053 };
1054
1055 static int vhci_hcd_probe(struct platform_device *pdev)
1056 {
1057         struct usb_hcd          *hcd;
1058         int                     ret;
1059
1060         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1061
1062         /*
1063          * Allocate and initialize hcd.
1064          * Our private data is also allocated automatically.
1065          */
1066         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1067         if (!hcd) {
1068                 pr_err("create hcd failed\n");
1069                 return -ENOMEM;
1070         }
1071         hcd->has_tt = 1;
1072
1073         /*
1074          * Finish generic HCD structure initialization and register.
1075          * Call the driver's reset() and start() routines.
1076          */
1077         ret = usb_add_hcd(hcd, 0, 0);
1078         if (ret != 0) {
1079                 pr_err("usb_add_hcd failed %d\n", ret);
1080                 usb_put_hcd(hcd);
1081                 return ret;
1082         }
1083
1084         usbip_dbg_vhci_hc("bye\n");
1085         return 0;
1086 }
1087
1088 static int vhci_hcd_remove(struct platform_device *pdev)
1089 {
1090         struct usb_hcd  *hcd;
1091
1092         hcd = platform_get_drvdata(pdev);
1093         if (!hcd)
1094                 return 0;
1095
1096         /*
1097          * Disconnects the root hub,
1098          * then reverses the effects of usb_add_hcd(),
1099          * invoking the HCD's stop() methods.
1100          */
1101         usb_remove_hcd(hcd);
1102         usb_put_hcd(hcd);
1103
1104         return 0;
1105 }
1106
1107 #ifdef CONFIG_PM
1108
1109 /* what should happen for USB/IP under suspend/resume? */
1110 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1111 {
1112         struct usb_hcd *hcd;
1113         struct vhci_hcd *vhci;
1114         int rhport;
1115         int connected = 0;
1116         int ret = 0;
1117         unsigned long flags;
1118
1119         hcd = platform_get_drvdata(pdev);
1120         if (!hcd)
1121                 return 0;
1122         vhci = hcd_to_vhci(hcd);
1123
1124         spin_lock_irqsave(&vhci->lock, flags);
1125
1126         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++)
1127                 if (vhci->port_status[rhport] & USB_PORT_STAT_CONNECTION)
1128                         connected += 1;
1129
1130         spin_unlock_irqrestore(&vhci->lock, flags);
1131
1132         if (connected > 0) {
1133                 dev_info(&pdev->dev,
1134                          "We have %d active connection%s. Do not suspend.\n",
1135                          connected, (connected == 1 ? "" : "s"));
1136                 ret =  -EBUSY;
1137         } else {
1138                 dev_info(&pdev->dev, "suspend vhci_hcd");
1139                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1140         }
1141
1142         return ret;
1143 }
1144
1145 static int vhci_hcd_resume(struct platform_device *pdev)
1146 {
1147         struct usb_hcd *hcd;
1148
1149         dev_dbg(&pdev->dev, "%s\n", __func__);
1150
1151         hcd = platform_get_drvdata(pdev);
1152         if (!hcd)
1153                 return 0;
1154         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1155         usb_hcd_poll_rh_status(hcd);
1156
1157         return 0;
1158 }
1159
1160 #else
1161
1162 #define vhci_hcd_suspend        NULL
1163 #define vhci_hcd_resume         NULL
1164
1165 #endif
1166
1167 static struct platform_driver vhci_driver = {
1168         .probe  = vhci_hcd_probe,
1169         .remove = vhci_hcd_remove,
1170         .suspend = vhci_hcd_suspend,
1171         .resume = vhci_hcd_resume,
1172         .driver = {
1173                 .name = driver_name,
1174         },
1175 };
1176
1177 static int add_platform_device(int id)
1178 {
1179         struct platform_device *pdev;
1180         int dev_nr;
1181
1182         if (id == 0)
1183                 dev_nr = -1;
1184         else
1185                 dev_nr = id;
1186
1187         pdev = platform_device_register_simple(driver_name, dev_nr, NULL, 0);
1188         if (IS_ERR(pdev))
1189                 return PTR_ERR(pdev);
1190
1191         *(vhci_pdevs + id) = pdev;
1192         return 0;
1193 }
1194
1195 static void del_platform_devices(void)
1196 {
1197         struct platform_device *pdev;
1198         int i;
1199
1200         for (i = 0; i < vhci_num_controllers; i++) {
1201                 pdev = *(vhci_pdevs + i);
1202                 if (pdev != NULL)
1203                         platform_device_unregister(pdev);
1204                 *(vhci_pdevs + i) = NULL;
1205         }
1206         sysfs_remove_link(&platform_bus.kobj, driver_name);
1207 }
1208
1209 static int __init vhci_hcd_init(void)
1210 {
1211         int i, ret;
1212
1213         if (usb_disabled())
1214                 return -ENODEV;
1215
1216         if (vhci_num_controllers < 1)
1217                 vhci_num_controllers = 1;
1218
1219         vhci_pdevs = kcalloc(vhci_num_controllers, sizeof(void *), GFP_KERNEL);
1220         if (vhci_pdevs == NULL)
1221                 return -ENOMEM;
1222
1223         ret = platform_driver_register(&vhci_driver);
1224         if (ret)
1225                 goto err_driver_register;
1226
1227         for (i = 0; i < vhci_num_controllers; i++) {
1228                 ret = add_platform_device(i);
1229                 if (ret)
1230                         goto err_platform_device_register;
1231         }
1232
1233         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1234         return ret;
1235
1236 err_platform_device_register:
1237         del_platform_devices();
1238         platform_driver_unregister(&vhci_driver);
1239 err_driver_register:
1240         kfree(vhci_pdevs);
1241         return ret;
1242 }
1243
1244 static void __exit vhci_hcd_exit(void)
1245 {
1246         del_platform_devices();
1247         platform_driver_unregister(&vhci_driver);
1248         kfree(vhci_pdevs);
1249 }
1250
1251 module_init(vhci_hcd_init);
1252 module_exit(vhci_hcd_exit);
1253
1254 MODULE_AUTHOR(DRIVER_AUTHOR);
1255 MODULE_DESCRIPTION(DRIVER_DESC);
1256 MODULE_LICENSE("GPL");
1257 MODULE_VERSION(USBIP_VERSION);