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] = 0;
 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                         break;
 322                 default:
 323                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 324                                           wValue);
 325                         dum->port_status[rhport] &= ~(1 << wValue);
 326                         break;
 327                 }
 328                 break;
 329         case GetHubDescriptor:
 330                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 331                 hub_descriptor((struct usb_hub_descriptor *) buf);
 332                 break;
 333         case GetHubStatus:
 334                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 335                 *(__le32 *) buf = cpu_to_le32(0);
 336                 break;
 337         case GetPortStatus:
 338                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 339                 if (wIndex > VHCI_HC_PORTS || wIndex < 1) {
 340                         pr_err("invalid port number %d\n", wIndex);
 341                         retval = -EPIPE;
 342                 }
 343
 344                 /* we do not care about resume. */
 345
 346                 /* whoever resets or resumes must GetPortStatus to
 347                  * complete it!!
 348                  */
 349                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 350                         dum->port_status[rhport] |=
 351                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 352                         dum->port_status[rhport] &=
 353                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 354                         dum->resuming = 0;
 355                         dum->re_timeout = 0;
 356                 }
 357
 358                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 359                     0 && time_after(jiffies, dum->re_timeout)) {
 360                         dum->port_status[rhport] |=
 361                                 (1 << USB_PORT_FEAT_C_RESET);
 362                         dum->port_status[rhport] &=
 363                                 ~(1 << USB_PORT_FEAT_RESET);
 364                         dum->re_timeout = 0;
 365
 366                         if (dum->vdev[rhport].ud.status ==
 367                             VDEV_ST_NOTASSIGNED) {
 368                                 usbip_dbg_vhci_rh(
 369                                         " enable rhport %d (status %u)\n",
 370                                         rhport,
 371                                         dum->vdev[rhport].ud.status);
 372                                 dum->port_status[rhport] |=
 373                                         USB_PORT_STAT_ENABLE;
 374                         }
 375                 }
 376                 ((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 377                 ((__le16 *) buf)[1] =
 378                         cpu_to_le16(dum->port_status[rhport] >> 16);
 379
 380                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 381                                   ((u16 *)buf)[1]);
 382                 break;
 383         case SetHubFeature:
 384                 usbip_dbg_vhci_rh(" SetHubFeature\n");
 385                 retval = -EPIPE;
 386                 break;
 387         case SetPortFeature:
 388                 switch (wValue) {
 389                 case USB_PORT_FEAT_SUSPEND:
 390                         usbip_dbg_vhci_rh(
 391                                 " SetPortFeature: USB_PORT_FEAT_SUSPEND\n");
 392                         break;
 393                 case USB_PORT_FEAT_RESET:
 394                         usbip_dbg_vhci_rh(
 395                                 " SetPortFeature: USB_PORT_FEAT_RESET\n");
 396                         /* if it's already running, disconnect first */
 397                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 398                                 dum->port_status[rhport] &=
 399                                         ~(USB_PORT_STAT_ENABLE |
 400                                           USB_PORT_STAT_LOW_SPEED |
 401                                           USB_PORT_STAT_HIGH_SPEED);
 402                                 /* FIXME test that code path! */
 403                         }
 404                         /* 50msec reset signaling */
 405                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
 406
 407                         /* FALLTHROUGH */
 408                 default:
 409                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 410                                           wValue);
 411                         dum->port_status[rhport] |= (1 << wValue);
 412                         break;
 413                 }
 414                 break;
 415
 416         default:
 417                 pr_err("default: no such request\n");
 418
 419                 /* "protocol stall" on error */
 420                 retval = -EPIPE;
 421         }
 422
 423         if (usbip_dbg_flag_vhci_rh) {
 424                 pr_debug("port %d\n", rhport);
 425                 /* Only dump valid port status */
 426                 if (rhport >= 0) {
 427                         dump_port_status_diff(prev_port_status[rhport],
 428                                               dum->port_status[rhport]);
 429                 }
 430         }
 431         usbip_dbg_vhci_rh(" bye\n");
 432
 433         spin_unlock_irqrestore(&dum->lock, flags);
 434
 435         return retval;
 436 }
 437
 438 static void vhci_tx_urb(struct urb *urb, struct vhci_device *vdev)
 439 {
 440         struct vhci_priv *priv;
 441         struct vhci_hcd *vhci;
 442         unsigned long flags;
 443
 444         if (!vdev) {
 445                 pr_err("could not get virtual device");
 446                 return;
 447         }
 448         vhci = vdev_to_vhci(vdev);
 449
 450         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 451         if (!priv) {
 452                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 453                 return;
 454         }
 455
 456         spin_lock_irqsave(&vdev->priv_lock, flags);
 457
 458         priv->seqnum = atomic_inc_return(&vhci->seqnum);
 459         if (priv->seqnum == 0xffff)
 460                 dev_info(&urb->dev->dev, "seqnum max\n");
 461
 462         priv->vdev = vdev;
 463         priv->urb = urb;
 464
 465         urb->hcpriv = (void *) priv;
 466
 467         list_add_tail(&priv->list, &vdev->priv_tx);
 468
 469         wake_up(&vdev->waitq_tx);
 470         spin_unlock_irqrestore(&vdev->priv_lock, flags);
 471 }
 472
 473 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 474                             gfp_t mem_flags)
 475 {
 476         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 477         struct device *dev = &urb->dev->dev;
 478         u8 portnum = urb->dev->portnum;
 479         int ret = 0;
 480         struct vhci_device *vdev;
 481         unsigned long flags;
 482
 483         usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
 484                           hcd, urb, mem_flags);
 485
 486         if (portnum > VHCI_HC_PORTS) {
 487                 pr_err("invalid port number %d\n", portnum);
 488                 return -ENODEV;
 489         }
 490         vdev = &vhci->vdev[portnum-1];
 491
 492         /* patch to usb_sg_init() is in 2.5.60 */
 493         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 494
 495         spin_lock_irqsave(&vhci->lock, flags);
 496
 497         if (urb->status != -EINPROGRESS) {
 498                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 499                 spin_unlock_irqrestore(&vhci->lock, flags);
 500                 return urb->status;
 501         }
 502
 503         /* refuse enqueue for dead connection */
 504         spin_lock(&vdev->ud.lock);
 505         if (vdev->ud.status == VDEV_ST_NULL ||
 506             vdev->ud.status == VDEV_ST_ERROR) {
 507                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 508                 spin_unlock(&vdev->ud.lock);
 509                 spin_unlock_irqrestore(&vhci->lock, flags);
 510                 return -ENODEV;
 511         }
 512         spin_unlock(&vdev->ud.lock);
 513
 514         ret = usb_hcd_link_urb_to_ep(hcd, urb);
 515         if (ret)
 516                 goto no_need_unlink;
 517
 518         /*
 519          * The enumeration process is as follows;
 520          *
 521          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 522          *     to get max packet length of default pipe
 523          *
 524          *  2. Set_Address request to DevAddr(0) EndPoint(0)
 525          *
 526          */
 527         if (usb_pipedevice(urb->pipe) == 0) {
 528                 __u8 type = usb_pipetype(urb->pipe);
 529                 struct usb_ctrlrequest *ctrlreq =
 530                         (struct usb_ctrlrequest *) urb->setup_packet;
 531
 532                 if (type != PIPE_CONTROL || !ctrlreq) {
 533                         dev_err(dev, "invalid request to devnum 0\n");
 534                         ret = -EINVAL;
 535                         goto no_need_xmit;
 536                 }
 537
 538                 switch (ctrlreq->bRequest) {
 539                 case USB_REQ_SET_ADDRESS:
 540                         /* set_address may come when a device is reset */
 541                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
 542                                  ctrlreq->wValue, vdev->rhport);
 543
 544                         usb_put_dev(vdev->udev);
 545                         vdev->udev = usb_get_dev(urb->dev);
 546
 547                         spin_lock(&vdev->ud.lock);
 548                         vdev->ud.status = VDEV_ST_USED;
 549                         spin_unlock(&vdev->ud.lock);
 550
 551                         if (urb->status == -EINPROGRESS) {
 552                                 /* This request is successfully completed. */
 553                                 /* If not -EINPROGRESS, possibly unlinked. */
 554                                 urb->status = 0;
 555                         }
 556
 557                         goto no_need_xmit;
 558
 559                 case USB_REQ_GET_DESCRIPTOR:
 560                         if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
 561                                 usbip_dbg_vhci_hc(
 562                                         "Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
 563
 564                         usb_put_dev(vdev->udev);
 565                         vdev->udev = usb_get_dev(urb->dev);
 566                         goto out;
 567
 568                 default:
 569                         /* NOT REACHED */
 570                         dev_err(dev,
 571                                 "invalid request to devnum 0 bRequest %u, wValue %u\n",
 572                                 ctrlreq->bRequest,
 573                                 ctrlreq->wValue);
 574                         ret =  -EINVAL;
 575                         goto no_need_xmit;
 576                 }
 577
 578         }
 579
 580 out:
 581         vhci_tx_urb(urb, vdev);
 582         spin_unlock_irqrestore(&vhci->lock, flags);
 583
 584         return 0;
 585
 586 no_need_xmit:
 587         usb_hcd_unlink_urb_from_ep(hcd, urb);
 588 no_need_unlink:
 589         spin_unlock_irqrestore(&vhci->lock, flags);
 590         if (!ret)
 591                 usb_hcd_giveback_urb(hcd, urb, urb->status);
 592         return ret;
 593 }
 594
 595 /*
 596  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 597  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 598  * back its urb. For the driver unlinking the urb, the content of the urb is
 599  * not important, but the calling to its completion handler is important; the
 600  * completion of unlinking is notified by the completion handler.
 601  *
 602  *
 603  * CLIENT SIDE
 604  *
 605  * - When vhci_hcd receives RET_SUBMIT,
 606  *
 607  *      - case 1a). the urb of the pdu is not unlinking.
 608  *              - normal case
 609  *              => just give back the urb
 610  *
 611  *      - case 1b). the urb of the pdu is unlinking.
 612  *              - usbip.ko will return a reply of the unlinking request.
 613  *              => give back the urb now and go to case 2b).
 614  *
 615  * - When vhci_hcd receives RET_UNLINK,
 616  *
 617  *      - case 2a). a submit request is still pending in vhci_hcd.
 618  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 619  *                completed there.
 620  *              => free a pending submit request
 621  *              => notify unlink completeness by giving back the urb
 622  *
 623  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 624  *              - urb was already given back to the core driver.
 625  *              => do not give back the urb
 626  *
 627  *
 628  * SERVER SIDE
 629  *
 630  * - When usbip receives CMD_UNLINK,
 631  *
 632  *      - case 3a). the urb of the unlink request is now in submission.
 633  *              => do usb_unlink_urb().
 634  *              => after the unlink is completed, send RET_UNLINK.
 635  *
 636  *      - case 3b). the urb of the unlink request is not in submission.
 637  *              - may be already completed or never be received
 638  *              => send RET_UNLINK
 639  *
 640  */
 641 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 642 {
 643         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 644         struct vhci_priv *priv;
 645         struct vhci_device *vdev;
 646         unsigned long flags;
 647
 648         pr_info("dequeue a urb %p\n", urb);
 649
 650         spin_lock_irqsave(&vhci->lock, flags);
 651
 652         priv = urb->hcpriv;
 653         if (!priv) {
 654                 /* URB was never linked! or will be soon given back by
 655                  * vhci_rx. */
 656                 spin_unlock_irqrestore(&vhci->lock, flags);
 657                 return -EIDRM;
 658         }
 659
 660         {
 661                 int ret = 0;
 662
 663                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 664                 if (ret) {
 665                         spin_unlock_irqrestore(&vhci->lock, flags);
 666                         return ret;
 667                 }
 668         }
 669
 670          /* send unlink request here? */
 671         vdev = priv->vdev;
 672
 673         if (!vdev->ud.tcp_socket) {
 674                 /* tcp connection is closed */
 675                 spin_lock(&vdev->priv_lock);
 676
 677                 pr_info("device %p seems to be disconnected\n", vdev);
 678                 list_del(&priv->list);
 679                 kfree(priv);
 680                 urb->hcpriv = NULL;
 681
 682                 spin_unlock(&vdev->priv_lock);
 683
 684                 /*
 685                  * If tcp connection is alive, we have sent CMD_UNLINK.
 686                  * vhci_rx will receive RET_UNLINK and give back the URB.
 687                  * Otherwise, we give back it here.
 688                  */
 689                 pr_info("gives back urb %p\n", urb);
 690
 691                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 692
 693                 spin_unlock_irqrestore(&vhci->lock, flags);
 694                 usb_hcd_giveback_urb(vhci_to_hcd(vhci), urb, urb->status);
 695                 spin_lock_irqsave(&vhci->lock, flags);
 696
 697         } else {
 698                 /* tcp connection is alive */
 699                 struct vhci_unlink *unlink;
 700
 701                 spin_lock(&vdev->priv_lock);
 702
 703                 /* setup CMD_UNLINK pdu */
 704                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 705                 if (!unlink) {
 706                         spin_unlock(&vdev->priv_lock);
 707                         spin_unlock_irqrestore(&vhci->lock, flags);
 708                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 709                         return -ENOMEM;
 710                 }
 711
 712                 unlink->seqnum = atomic_inc_return(&vhci->seqnum);
 713                 if (unlink->seqnum == 0xffff)
 714                         pr_info("seqnum max\n");
 715
 716                 unlink->unlink_seqnum = priv->seqnum;
 717
 718                 pr_info("device %p seems to be still connected\n", vdev);
 719
 720                 /* send cmd_unlink and try to cancel the pending URB in the
 721                  * peer */
 722                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 723                 wake_up(&vdev->waitq_tx);
 724
 725                 spin_unlock(&vdev->priv_lock);
 726         }
 727
 728         spin_unlock_irqrestore(&vhci->lock, flags);
 729
 730         usbip_dbg_vhci_hc("leave\n");
 731         return 0;
 732 }
 733
 734 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 735 {
 736         struct vhci_hcd *vhci = vdev_to_vhci(vdev);
 737         struct usb_hcd *hcd = vhci_to_hcd(vhci);
 738         struct vhci_unlink *unlink, *tmp;
 739         unsigned long flags;
 740
 741         spin_lock_irqsave(&vhci->lock, flags);
 742         spin_lock(&vdev->priv_lock);
 743
 744         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 745                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 746                 list_del(&unlink->list);
 747                 kfree(unlink);
 748         }
 749
 750         while (!list_empty(&vdev->unlink_rx)) {
 751                 struct urb *urb;
 752
 753                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 754                         list);
 755
 756                 /* give back URB of unanswered unlink request */
 757                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 758
 759                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 760                 if (!urb) {
 761                         pr_info("the urb (seqnum %lu) was already given back\n",
 762                                 unlink->unlink_seqnum);
 763                         list_del(&unlink->list);
 764                         kfree(unlink);
 765                         continue;
 766                 }
 767
 768                 urb->status = -ENODEV;
 769
 770                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 771
 772                 list_del(&unlink->list);
 773
 774                 spin_unlock(&vdev->priv_lock);
 775                 spin_unlock_irqrestore(&vhci->lock, flags);
 776
 777                 usb_hcd_giveback_urb(hcd, urb, urb->status);
 778
 779                 spin_lock_irqsave(&vhci->lock, flags);
 780                 spin_lock(&vdev->priv_lock);
 781
 782                 kfree(unlink);
 783         }
 784
 785         spin_unlock(&vdev->priv_lock);
 786         spin_unlock_irqrestore(&vhci->lock, flags);
 787 }
 788
 789 /*
 790  * The important thing is that only one context begins cleanup.
 791  * This is why error handling and cleanup become simple.
 792  * We do not want to consider race condition as possible.
 793  */
 794 static void vhci_shutdown_connection(struct usbip_device *ud)
 795 {
 796         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 797
 798         /* need this? see stub_dev.c */
 799         if (ud->tcp_socket) {
 800                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 801                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 802         }
 803
 804         /* kill threads related to this sdev */
 805         if (vdev->ud.tcp_rx) {
 806                 kthread_stop_put(vdev->ud.tcp_rx);
 807                 vdev->ud.tcp_rx = NULL;
 808         }
 809         if (vdev->ud.tcp_tx) {
 810                 kthread_stop_put(vdev->ud.tcp_tx);
 811                 vdev->ud.tcp_tx = NULL;
 812         }
 813         pr_info("stop threads\n");
 814
 815         /* active connection is closed */
 816         if (vdev->ud.tcp_socket) {
 817                 sockfd_put(vdev->ud.tcp_socket);
 818                 vdev->ud.tcp_socket = NULL;
 819         }
 820         pr_info("release socket\n");
 821
 822         vhci_device_unlink_cleanup(vdev);
 823
 824         /*
 825          * rh_port_disconnect() is a trigger of ...
 826          *   usb_disable_device():
 827          *      disable all the endpoints for a USB device.
 828          *   usb_disable_endpoint():
 829          *      disable endpoints. pending urbs are unlinked(dequeued).
 830          *
 831          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 832          * detached device should release used urbs in a cleanup function (i.e.
 833          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 834          * pushed urbs and their private data in this function.
 835          *
 836          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 837          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 838          * gives back pushed urbs and frees their private data by request of
 839          * the cleanup function of a USB driver. When unlinking a urb with an
 840          * active connection, vhci_dequeue() does not give back the urb which
 841          * is actually given back by vhci_rx after receiving its return pdu.
 842          *
 843          */
 844         rh_port_disconnect(vdev);
 845
 846         pr_info("disconnect device\n");
 847 }
 848
 849
 850 static void vhci_device_reset(struct usbip_device *ud)
 851 {
 852         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 853         unsigned long flags;
 854
 855         spin_lock_irqsave(&ud->lock, flags);
 856
 857         vdev->speed  = 0;
 858         vdev->devid  = 0;
 859
 860         usb_put_dev(vdev->udev);
 861         vdev->udev = NULL;
 862
 863         if (ud->tcp_socket) {
 864                 sockfd_put(ud->tcp_socket);
 865                 ud->tcp_socket = NULL;
 866         }
 867         ud->status = VDEV_ST_NULL;
 868
 869         spin_unlock_irqrestore(&ud->lock, flags);
 870 }
 871
 872 static void vhci_device_unusable(struct usbip_device *ud)
 873 {
 874         unsigned long flags;
 875
 876         spin_lock_irqsave(&ud->lock, flags);
 877         ud->status = VDEV_ST_ERROR;
 878         spin_unlock_irqrestore(&ud->lock, flags);
 879 }
 880
 881 static void vhci_device_init(struct vhci_device *vdev)
 882 {
 883         memset(vdev, 0, sizeof(struct vhci_device));
 884
 885         vdev->ud.side   = USBIP_VHCI;
 886         vdev->ud.status = VDEV_ST_NULL;
 887         spin_lock_init(&vdev->ud.lock);
 888
 889         INIT_LIST_HEAD(&vdev->priv_rx);
 890         INIT_LIST_HEAD(&vdev->priv_tx);
 891         INIT_LIST_HEAD(&vdev->unlink_tx);
 892         INIT_LIST_HEAD(&vdev->unlink_rx);
 893         spin_lock_init(&vdev->priv_lock);
 894
 895         init_waitqueue_head(&vdev->waitq_tx);
 896
 897         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 898         vdev->ud.eh_ops.reset = vhci_device_reset;
 899         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 900
 901         usbip_start_eh(&vdev->ud);
 902 }
 903
 904 static int hcd_name_to_id(const char *name)
 905 {
 906         char *c;
 907         long val;
 908         int ret;
 909
 910         c = strchr(name, '.');
 911         if (c == NULL)
 912                 return 0;
 913
 914         ret = kstrtol(c+1, 10, &val);
 915         if (ret < 0)
 916                 return ret;
 917
 918         return val;
 919 }
 920
 921 static int vhci_start(struct usb_hcd *hcd)
 922 {
 923         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 924         int id, rhport;
 925         int err = 0;
 926
 927         usbip_dbg_vhci_hc("enter vhci_start\n");
 928
 929         /* initialize private data of usb_hcd */
 930
 931         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 932                 struct vhci_device *vdev = &vhci->vdev[rhport];
 933
 934                 vhci_device_init(vdev);
 935                 vdev->rhport = rhport;
 936         }
 937
 938         atomic_set(&vhci->seqnum, 0);
 939         spin_lock_init(&vhci->lock);
 940
 941         hcd->power_budget = 0; /* no limit */
 942         hcd->uses_new_polling = 1;
 943
 944         id = hcd_name_to_id(hcd_name(hcd));
 945         if (id < 0) {
 946                 pr_err("invalid vhci name %s\n", hcd_name(hcd));
 947                 return -EINVAL;
 948         }
 949
 950         /* vhci_hcd is now ready to be controlled through sysfs */
 951         if (id == 0) {
 952                 err = vhci_init_attr_group();
 953                 if (err) {
 954                         pr_err("init attr group\n");
 955                         return err;
 956                 }
 957                 err = sysfs_create_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
 958                 if (err) {
 959                         pr_err("create sysfs files\n");
 960                         vhci_finish_attr_group();
 961                         return err;
 962                 }
 963                 pr_info("created sysfs %s\n", hcd_name(hcd));
 964         }
 965
 966         return 0;
 967 }
 968
 969 static void vhci_stop(struct usb_hcd *hcd)
 970 {
 971         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 972         int id, rhport;
 973
 974         usbip_dbg_vhci_hc("stop VHCI controller\n");
 975
 976         /* 1. remove the userland interface of vhci_hcd */
 977         id = hcd_name_to_id(hcd_name(hcd));
 978         if (id == 0) {
 979                 sysfs_remove_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
 980                 vhci_finish_attr_group();
 981         }
 982
 983         /* 2. shutdown all the ports of vhci_hcd */
 984         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 985                 struct vhci_device *vdev = &vhci->vdev[rhport];
 986
 987                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
 988                 usbip_stop_eh(&vdev->ud);
 989         }
 990 }
 991
 992 static int vhci_get_frame_number(struct usb_hcd *hcd)
 993 {
 994         dev_err_ratelimited(&hcd->self.root_hub->dev, "Not yet implemented\n");
 995         return 0;
 996 }
 997
 998 #ifdef CONFIG_PM
 999
1000 /* FIXME: suspend/resume */
1001 static int vhci_bus_suspend(struct usb_hcd *hcd)
1002 {
1003         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1004         unsigned long flags;
1005
1006         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1007
1008         spin_lock_irqsave(&vhci->lock, flags);
1009         hcd->state = HC_STATE_SUSPENDED;
1010         spin_unlock_irqrestore(&vhci->lock, flags);
1011
1012         return 0;
1013 }
1014
1015 static int vhci_bus_resume(struct usb_hcd *hcd)
1016 {
1017         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
1018         int rc = 0;
1019         unsigned long flags;
1020
1021         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
1022
1023         spin_lock_irqsave(&vhci->lock, flags);
1024         if (!HCD_HW_ACCESSIBLE(hcd))
1025                 rc = -ESHUTDOWN;
1026         else
1027                 hcd->state = HC_STATE_RUNNING;
1028         spin_unlock_irqrestore(&vhci->lock, flags);
1029
1030         return rc;
1031 }
1032
1033 #else
1034
1035 #define vhci_bus_suspend      NULL
1036 #define vhci_bus_resume       NULL
1037 #endif
1038
1039 static struct hc_driver vhci_hc_driver = {
1040         .description    = driver_name,
1041         .product_desc   = driver_desc,
1042         .hcd_priv_size  = sizeof(struct vhci_hcd),
1043
1044         .flags          = HCD_USB2,
1045
1046         .start          = vhci_start,
1047         .stop           = vhci_stop,
1048
1049         .urb_enqueue    = vhci_urb_enqueue,
1050         .urb_dequeue    = vhci_urb_dequeue,
1051
1052         .get_frame_number = vhci_get_frame_number,
1053
1054         .hub_status_data = vhci_hub_status,
1055         .hub_control    = vhci_hub_control,
1056         .bus_suspend    = vhci_bus_suspend,
1057         .bus_resume     = vhci_bus_resume,
1058 };
1059
1060 static int vhci_hcd_probe(struct platform_device *pdev)
1061 {
1062         struct usb_hcd          *hcd;
1063         int                     ret;
1064
1065         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1066
1067         /*
1068          * Allocate and initialize hcd.
1069          * Our private data is also allocated automatically.
1070          */
1071         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1072         if (!hcd) {
1073                 pr_err("create hcd failed\n");
1074                 return -ENOMEM;
1075         }
1076         hcd->has_tt = 1;
1077
1078         /*
1079          * Finish generic HCD structure initialization and register.
1080          * Call the driver's reset() and start() routines.
1081          */
1082         ret = usb_add_hcd(hcd, 0, 0);
1083         if (ret != 0) {
1084                 pr_err("usb_add_hcd failed %d\n", ret);
1085                 usb_put_hcd(hcd);
1086                 return ret;
1087         }
1088
1089         usbip_dbg_vhci_hc("bye\n");
1090         return 0;
1091 }
1092
1093 static int vhci_hcd_remove(struct platform_device *pdev)
1094 {
1095         struct usb_hcd  *hcd;
1096
1097         hcd = platform_get_drvdata(pdev);
1098         if (!hcd)
1099                 return 0;
1100
1101         /*
1102          * Disconnects the root hub,
1103          * then reverses the effects of usb_add_hcd(),
1104          * invoking the HCD's stop() methods.
1105          */
1106         usb_remove_hcd(hcd);
1107         usb_put_hcd(hcd);
1108
1109         return 0;
1110 }
1111
1112 #ifdef CONFIG_PM
1113
1114 /* what should happen for USB/IP under suspend/resume? */
1115 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1116 {
1117         struct usb_hcd *hcd;
1118         struct vhci_hcd *vhci;
1119         int rhport;
1120         int connected = 0;
1121         int ret = 0;
1122         unsigned long flags;
1123
1124         hcd = platform_get_drvdata(pdev);
1125         if (!hcd)
1126                 return 0;
1127         vhci = hcd_to_vhci(hcd);
1128
1129         spin_lock_irqsave(&vhci->lock, flags);
1130
1131         for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++)
1132                 if (vhci->port_status[rhport] & USB_PORT_STAT_CONNECTION)
1133                         connected += 1;
1134
1135         spin_unlock_irqrestore(&vhci->lock, flags);
1136
1137         if (connected > 0) {
1138                 dev_info(&pdev->dev,
1139                          "We have %d active connection%s. Do not suspend.\n",
1140                          connected, (connected == 1 ? "" : "s"));
1141                 ret =  -EBUSY;
1142         } else {
1143                 dev_info(&pdev->dev, "suspend vhci_hcd");
1144                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1145         }
1146
1147         return ret;
1148 }
1149
1150 static int vhci_hcd_resume(struct platform_device *pdev)
1151 {
1152         struct usb_hcd *hcd;
1153
1154         dev_dbg(&pdev->dev, "%s\n", __func__);
1155
1156         hcd = platform_get_drvdata(pdev);
1157         if (!hcd)
1158                 return 0;
1159         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1160         usb_hcd_poll_rh_status(hcd);
1161
1162         return 0;
1163 }
1164
1165 #else
1166
1167 #define vhci_hcd_suspend        NULL
1168 #define vhci_hcd_resume         NULL
1169
1170 #endif
1171
1172 static struct platform_driver vhci_driver = {
1173         .probe  = vhci_hcd_probe,
1174         .remove = vhci_hcd_remove,
1175         .suspend = vhci_hcd_suspend,
1176         .resume = vhci_hcd_resume,
1177         .driver = {
1178                 .name = driver_name,
1179         },
1180 };
1181
1182 static int add_platform_device(int id)
1183 {
1184         struct platform_device *pdev;
1185         int dev_nr;
1186
1187         if (id == 0)
1188                 dev_nr = -1;
1189         else
1190                 dev_nr = id;
1191
1192         pdev = platform_device_register_simple(driver_name, dev_nr, NULL, 0);
1193         if (IS_ERR(pdev))
1194                 return PTR_ERR(pdev);
1195
1196         *(vhci_pdevs + id) = pdev;
1197         return 0;
1198 }
1199
1200 static void del_platform_devices(void)
1201 {
1202         struct platform_device *pdev;
1203         int i;
1204
1205         for (i = 0; i < vhci_num_controllers; i++) {
1206                 pdev = *(vhci_pdevs + i);
1207                 if (pdev != NULL)
1208                         platform_device_unregister(pdev);
1209                 *(vhci_pdevs + i) = NULL;
1210         }
1211         sysfs_remove_link(&platform_bus.kobj, driver_name);
1212 }
1213
1214 static int __init vhci_hcd_init(void)
1215 {
1216         int i, ret;
1217
1218         if (usb_disabled())
1219                 return -ENODEV;
1220
1221         if (vhci_num_controllers < 1)
1222                 vhci_num_controllers = 1;
1223
1224         vhci_pdevs = kcalloc(vhci_num_controllers, sizeof(void *), GFP_KERNEL);
1225         if (vhci_pdevs == NULL)
1226                 return -ENOMEM;
1227
1228         ret = platform_driver_register(&vhci_driver);
1229         if (ret)
1230                 goto err_driver_register;
1231
1232         for (i = 0; i < vhci_num_controllers; i++) {
1233                 ret = add_platform_device(i);
1234                 if (ret)
1235                         goto err_platform_device_register;
1236         }
1237
1238         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1239         return ret;
1240
1241 err_platform_device_register:
1242         del_platform_devices();
1243         platform_driver_unregister(&vhci_driver);
1244 err_driver_register:
1245         kfree(vhci_pdevs);
1246         return ret;
1247 }
1248
1249 static void __exit vhci_hcd_exit(void)
1250 {
1251         del_platform_devices();
1252         platform_driver_unregister(&vhci_driver);
1253         kfree(vhci_pdevs);
1254 }
1255
1256 module_init(vhci_hcd_init);
1257 module_exit(vhci_hcd_exit);
1258
1259 MODULE_AUTHOR(DRIVER_AUTHOR);
1260 MODULE_DESCRIPTION(DRIVER_DESC);
1261 MODULE_LICENSE("GPL");
1262 MODULE_VERSION(USBIP_VERSION);