Pileus Git - ~andy/linux/blob - drivers/staging/usbip/vhci_hcd.c

   1 /*
   2  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   3  *
   4  * This is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17  * USA.
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/file.h>
  22 #include <linux/kernel.h>
  23 #include <linux/kthread.h>
  24 #include <linux/module.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/slab.h>
  27
  28 #include "usbip_common.h"
  29 #include "vhci.h"
  30
  31 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
  32 #define DRIVER_DESC "USB/IP 'Virtual' Host Controller (VHCI) Driver"
  33
  34 /*
  35  * TODO
  36  *      - update root hub emulation
  37  *      - move the emulation code to userland ?
  38  *              porting to other operating systems
  39  *              minimize kernel code
  40  *      - add suspend/resume code
  41  *      - clean up everything
  42  */
  43
  44 /* See usb gadget dummy hcd */
  45
  46 static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
  47 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
  48                             u16 wIndex, char *buff, u16 wLength);
  49 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
  50                             gfp_t mem_flags);
  51 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
  52 static int vhci_start(struct usb_hcd *vhci_hcd);
  53 static void vhci_stop(struct usb_hcd *hcd);
  54 static int vhci_get_frame_number(struct usb_hcd *hcd);
  55
  56 static const char driver_name[] = "vhci_hcd";
  57 static const char driver_desc[] = "USB/IP Virtual Host Controller";
  58
  59 struct vhci_hcd *the_controller;
  60
  61 static const char * const bit_desc[] = {
  62         "CONNECTION",           /*0*/
  63         "ENABLE",               /*1*/
  64         "SUSPEND",              /*2*/
  65         "OVER_CURRENT",         /*3*/
  66         "RESET",                /*4*/
  67         "R5",                   /*5*/
  68         "R6",                   /*6*/
  69         "R7",                   /*7*/
  70         "POWER",                /*8*/
  71         "LOWSPEED",             /*9*/
  72         "HIGHSPEED",            /*10*/
  73         "PORT_TEST",            /*11*/
  74         "INDICATOR",            /*12*/
  75         "R13",                  /*13*/
  76         "R14",                  /*14*/
  77         "R15",                  /*15*/
  78         "C_CONNECTION",         /*16*/
  79         "C_ENABLE",             /*17*/
  80         "C_SUSPEND",            /*18*/
  81         "C_OVER_CURRENT",       /*19*/
  82         "C_RESET",              /*20*/
  83         "R21",                  /*21*/
  84         "R22",                  /*22*/
  85         "R23",                  /*23*/
  86         "R24",                  /*24*/
  87         "R25",                  /*25*/
  88         "R26",                  /*26*/
  89         "R27",                  /*27*/
  90         "R28",                  /*28*/
  91         "R29",                  /*29*/
  92         "R30",                  /*30*/
  93         "R31",                  /*31*/
  94 };
  95
  96 static void dump_port_status_diff(u32 prev_status, u32 new_status)
  97 {
  98         int i = 0;
  99         u32 bit = 1;
 100
 101         pr_debug("status prev -> new: %08x -> %08x\n", prev_status, new_status);
 102         while (bit) {
 103                 u32 prev = prev_status & bit;
 104                 u32 new = new_status & bit;
 105                 char change;
 106
 107                 if (!prev && new)
 108                         change = '+';
 109                 else if (prev && !new)
 110                         change = '-';
 111                 else
 112                         change = ' ';
 113
 114                 if (prev || new)
 115                         pr_debug(" %c%s\n", change, bit_desc[i]);
 116                 bit <<= 1;
 117                 i++;
 118         }
 119         pr_debug("\n");
 120 }
 121
 122 void rh_port_connect(int rhport, enum usb_device_speed speed)
 123 {
 124         unsigned long   flags;
 125
 126         usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
 127
 128         spin_lock_irqsave(&the_controller->lock, flags);
 129
 130         the_controller->port_status[rhport] |= USB_PORT_STAT_CONNECTION
 131                 | (1 << USB_PORT_FEAT_C_CONNECTION);
 132
 133         switch (speed) {
 134         case USB_SPEED_HIGH:
 135                 the_controller->port_status[rhport] |= USB_PORT_STAT_HIGH_SPEED;
 136                 break;
 137         case USB_SPEED_LOW:
 138                 the_controller->port_status[rhport] |= USB_PORT_STAT_LOW_SPEED;
 139                 break;
 140         default:
 141                 break;
 142         }
 143
 144         spin_unlock_irqrestore(&the_controller->lock, flags);
 145
 146         usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
 147 }
 148
 149 static void rh_port_disconnect(int rhport)
 150 {
 151         unsigned long flags;
 152
 153         usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
 154
 155         spin_lock_irqsave(&the_controller->lock, flags);
 156
 157         the_controller->port_status[rhport] &= ~USB_PORT_STAT_CONNECTION;
 158         the_controller->port_status[rhport] |=
 159                                         (1 << USB_PORT_FEAT_C_CONNECTION);
 160
 161         spin_unlock_irqrestore(&the_controller->lock, flags);
 162         usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
 163 }
 164
 165 #define PORT_C_MASK                             \
 166         ((USB_PORT_STAT_C_CONNECTION            \
 167           | USB_PORT_STAT_C_ENABLE              \
 168           | USB_PORT_STAT_C_SUSPEND             \
 169           | USB_PORT_STAT_C_OVERCURRENT         \
 170           | USB_PORT_STAT_C_RESET) << 16)
 171
 172 /*
 173  * Returns 0 if the status hasn't changed, or the number of bytes in buf.
 174  * Ports are 0-indexed from the HCD point of view,
 175  * and 1-indexed from the USB core pointer of view.
 176  *
 177  * @buf: a bitmap to show which port status has been changed.
 178  *  bit  0: reserved
 179  *  bit  1: the status of port 0 has been changed.
 180  *  bit  2: the status of port 1 has been changed.
 181  *  ...
 182  */
 183 static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
 184 {
 185         struct vhci_hcd *vhci;
 186         unsigned long   flags;
 187         int             retval;
 188         int             rhport;
 189         int             changed = 0;
 190
 191         retval = DIV_ROUND_UP(VHCI_NPORTS + 1, 8);
 192         memset(buf, 0, retval);
 193
 194         vhci = hcd_to_vhci(hcd);
 195
 196         spin_lock_irqsave(&vhci->lock, flags);
 197         if (!HCD_HW_ACCESSIBLE(hcd)) {
 198                 usbip_dbg_vhci_rh("hw accessible flag not on?\n");
 199                 goto done;
 200         }
 201
 202         /* check pseudo status register for each port */
 203         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 204                 if ((vhci->port_status[rhport] & PORT_C_MASK)) {
 205                         /* The status of a port has been changed, */
 206                         usbip_dbg_vhci_rh("port %d status changed\n", rhport);
 207
 208                         buf[(rhport + 1) / 8] |= 1 << (rhport + 1) % 8;
 209                         changed = 1;
 210                 }
 211         }
 212
 213         pr_info("changed %d\n", changed);
 214
 215         if ((hcd->state == HC_STATE_SUSPENDED) && (changed == 1))
 216                 usb_hcd_resume_root_hub(hcd);
 217
 218 done:
 219         spin_unlock_irqrestore(&vhci->lock, flags);
 220         return changed ? retval : 0;
 221 }
 222
 223 static inline void hub_descriptor(struct usb_hub_descriptor *desc)
 224 {
 225         memset(desc, 0, sizeof(*desc));
 226         desc->bDescriptorType = 0x29;
 227         desc->bDescLength = 9;
 228         desc->wHubCharacteristics = (__force __u16)
 229                 (__constant_cpu_to_le16(0x0001));
 230         desc->bNbrPorts = VHCI_NPORTS;
 231         desc->u.hs.DeviceRemovable[0] = 0xff;
 232         desc->u.hs.DeviceRemovable[1] = 0xff;
 233 }
 234
 235 static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 236                             u16 wIndex, char *buf, u16 wLength)
 237 {
 238         struct vhci_hcd *dum;
 239         int             retval = 0;
 240         unsigned long   flags;
 241         int             rhport;
 242
 243         u32 prev_port_status[VHCI_NPORTS];
 244
 245         if (!HCD_HW_ACCESSIBLE(hcd))
 246                 return -ETIMEDOUT;
 247
 248         /*
 249          * NOTE:
 250          * wIndex shows the port number and begins from 1.
 251          */
 252         usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 253                           wIndex);
 254         if (wIndex > VHCI_NPORTS)
 255                 pr_err("invalid port number %d\n", wIndex);
 256         rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 257
 258         dum = hcd_to_vhci(hcd);
 259
 260         spin_lock_irqsave(&dum->lock, flags);
 261
 262         /* store old status and compare now and old later */
 263         if (usbip_dbg_flag_vhci_rh) {
 264                 memcpy(prev_port_status, dum->port_status,
 265                         sizeof(prev_port_status));
 266         }
 267
 268         switch (typeReq) {
 269         case ClearHubFeature:
 270                 usbip_dbg_vhci_rh(" ClearHubFeature\n");
 271                 break;
 272         case ClearPortFeature:
 273                 switch (wValue) {
 274                 case USB_PORT_FEAT_SUSPEND:
 275                         if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
 276                                 /* 20msec signaling */
 277                                 dum->resuming = 1;
 278                                 dum->re_timeout =
 279                                         jiffies + msecs_to_jiffies(20);
 280                         }
 281                         break;
 282                 case USB_PORT_FEAT_POWER:
 283                         usbip_dbg_vhci_rh(" ClearPortFeature: "
 284                                           "USB_PORT_FEAT_POWER\n");
 285                         dum->port_status[rhport] = 0;
 286                         dum->resuming = 0;
 287                         break;
 288                 case USB_PORT_FEAT_C_RESET:
 289                         usbip_dbg_vhci_rh(" ClearPortFeature: "
 290                                           "USB_PORT_FEAT_C_RESET\n");
 291                         switch (dum->vdev[rhport].speed) {
 292                         case USB_SPEED_HIGH:
 293                                 dum->port_status[rhport] |=
 294                                         USB_PORT_STAT_HIGH_SPEED;
 295                                 break;
 296                         case USB_SPEED_LOW:
 297                                 dum->port_status[rhport] |=
 298                                         USB_PORT_STAT_LOW_SPEED;
 299                                 break;
 300                         default:
 301                                 break;
 302                         }
 303                 default:
 304                         usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 305                                           wValue);
 306                         dum->port_status[rhport] &= ~(1 << wValue);
 307                         break;
 308                 }
 309                 break;
 310         case GetHubDescriptor:
 311                 usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 312                 hub_descriptor((struct usb_hub_descriptor *) buf);
 313                 break;
 314         case GetHubStatus:
 315                 usbip_dbg_vhci_rh(" GetHubStatus\n");
 316                 *(__le32 *) buf = __constant_cpu_to_le32(0);
 317                 break;
 318         case GetPortStatus:
 319                 usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 320                 if (wIndex > VHCI_NPORTS || wIndex < 1) {
 321                         pr_err("invalid port number %d\n", wIndex);
 322                         retval = -EPIPE;
 323                 }
 324
 325                 /* we do not care about resume. */
 326
 327                 /* whoever resets or resumes must GetPortStatus to
 328                  * complete it!!
 329                  */
 330                 if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 331                         dum->port_status[rhport] |=
 332                                 (1 << USB_PORT_FEAT_C_SUSPEND);
 333                         dum->port_status[rhport] &=
 334                                 ~(1 << USB_PORT_FEAT_SUSPEND);
 335                         dum->resuming = 0;
 336                         dum->re_timeout = 0;
 337                 }
 338
 339                 if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 340                     0 && time_after(jiffies, dum->re_timeout)) {
 341                         dum->port_status[rhport] |=
 342                                 (1 << USB_PORT_FEAT_C_RESET);
 343                         dum->port_status[rhport] &=
 344                                 ~(1 << USB_PORT_FEAT_RESET);
 345                         dum->re_timeout = 0;
 346
 347                         if (dum->vdev[rhport].ud.status ==
 348                             VDEV_ST_NOTASSIGNED) {
 349                                 usbip_dbg_vhci_rh(" enable rhport %d "
 350                                                   "(status %u)\n",
 351                                                   rhport,
 352                                                   dum->vdev[rhport].ud.status);
 353                                 dum->port_status[rhport] |=
 354                                         USB_PORT_STAT_ENABLE;
 355                         }
 356                 }
 357                 ((u16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 358                 ((u16 *) buf)[1] = cpu_to_le16(dum->port_status[rhport] >> 16);
 359
 360                 usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 361                                   ((u16 *)buf)[1]);
 362                 break;
 363         case SetHubFeature:
 364                 usbip_dbg_vhci_rh(" SetHubFeature\n");
 365                 retval = -EPIPE;
 366                 break;
 367         case SetPortFeature:
 368                 switch (wValue) {
 369                 case USB_PORT_FEAT_SUSPEND:
 370                         usbip_dbg_vhci_rh(" SetPortFeature: "
 371                                           "USB_PORT_FEAT_SUSPEND\n");
 372                         break;
 373                 case USB_PORT_FEAT_RESET:
 374                         usbip_dbg_vhci_rh(" SetPortFeature: "
 375                                           "USB_PORT_FEAT_RESET\n");
 376                         /* if it's already running, disconnect first */
 377                         if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 378                                 dum->port_status[rhport] &=
 379                                         ~(USB_PORT_STAT_ENABLE |
 380                                           USB_PORT_STAT_LOW_SPEED |
 381                                           USB_PORT_STAT_HIGH_SPEED);
 382                                 /* FIXME test that code path! */
 383                         }
 384                         /* 50msec reset signaling */
 385                         dum->re_timeout = jiffies + msecs_to_jiffies(50);
 386
 387                         /* FALLTHROUGH */
 388                 default:
 389                         usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 390                                           wValue);
 391                         dum->port_status[rhport] |= (1 << wValue);
 392                         break;
 393                 }
 394                 break;
 395
 396         default:
 397                 pr_err("default: no such request\n");
 398
 399                 /* "protocol stall" on error */
 400                 retval = -EPIPE;
 401         }
 402
 403         if (usbip_dbg_flag_vhci_rh) {
 404                 pr_debug("port %d\n", rhport);
 405                 /* Only dump valid port status */
 406                 if (rhport >= 0) {
 407                         dump_port_status_diff(prev_port_status[rhport],
 408                                               dum->port_status[rhport]);
 409                 }
 410         }
 411         usbip_dbg_vhci_rh(" bye\n");
 412
 413         spin_unlock_irqrestore(&dum->lock, flags);
 414
 415         return retval;
 416 }
 417
 418 static struct vhci_device *get_vdev(struct usb_device *udev)
 419 {
 420         int i;
 421
 422         if (!udev)
 423                 return NULL;
 424
 425         for (i = 0; i < VHCI_NPORTS; i++)
 426                 if (the_controller->vdev[i].udev == udev)
 427                         return port_to_vdev(i);
 428
 429         return NULL;
 430 }
 431
 432 static void vhci_tx_urb(struct urb *urb)
 433 {
 434         struct vhci_device *vdev = get_vdev(urb->dev);
 435         struct vhci_priv *priv;
 436         unsigned long flag;
 437
 438         if (!vdev) {
 439                 pr_err("could not get virtual device");
 440                 return;
 441         }
 442
 443         priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 444
 445         spin_lock_irqsave(&vdev->priv_lock, flag);
 446
 447         if (!priv) {
 448                 dev_err(&urb->dev->dev, "malloc vhci_priv\n");
 449                 spin_unlock_irqrestore(&vdev->priv_lock, flag);
 450                 usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 451                 return;
 452         }
 453
 454         priv->seqnum = atomic_inc_return(&the_controller->seqnum);
 455         if (priv->seqnum == 0xffff)
 456                 dev_info(&urb->dev->dev, "seqnum max\n");
 457
 458         priv->vdev = vdev;
 459         priv->urb = urb;
 460
 461         urb->hcpriv = (void *) priv;
 462
 463         list_add_tail(&priv->list, &vdev->priv_tx);
 464
 465         wake_up(&vdev->waitq_tx);
 466         spin_unlock_irqrestore(&vdev->priv_lock, flag);
 467 }
 468
 469 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 470                             gfp_t mem_flags)
 471 {
 472         struct device *dev = &urb->dev->dev;
 473         int ret = 0;
 474         unsigned long flags;
 475         struct vhci_device *vdev;
 476
 477         usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
 478                           hcd, urb, mem_flags);
 479
 480         /* patch to usb_sg_init() is in 2.5.60 */
 481         BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 482
 483         spin_lock_irqsave(&the_controller->lock, flags);
 484
 485         if (urb->status != -EINPROGRESS) {
 486                 dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 487                 spin_unlock_irqrestore(&the_controller->lock, flags);
 488                 return urb->status;
 489         }
 490
 491         vdev = port_to_vdev(urb->dev->portnum-1);
 492
 493         /* refuse enqueue for dead connection */
 494         spin_lock(&vdev->ud.lock);
 495         if (vdev->ud.status == VDEV_ST_NULL ||
 496             vdev->ud.status == VDEV_ST_ERROR) {
 497                 dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 498                 spin_unlock(&vdev->ud.lock);
 499                 spin_unlock_irqrestore(&the_controller->lock, flags);
 500                 return -ENODEV;
 501         }
 502         spin_unlock(&vdev->ud.lock);
 503
 504         ret = usb_hcd_link_urb_to_ep(hcd, urb);
 505         if (ret)
 506                 goto no_need_unlink;
 507
 508         /*
 509          * The enumeration process is as follows;
 510          *
 511          *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 512          *     to get max packet length of default pipe
 513          *
 514          *  2. Set_Address request to DevAddr(0) EndPoint(0)
 515          *
 516          */
 517         if (usb_pipedevice(urb->pipe) == 0) {
 518                 __u8 type = usb_pipetype(urb->pipe);
 519                 struct usb_ctrlrequest *ctrlreq =
 520                         (struct usb_ctrlrequest *) urb->setup_packet;
 521
 522                 if (type != PIPE_CONTROL || !ctrlreq) {
 523                         dev_err(dev, "invalid request to devnum 0\n");
 524                         ret = -EINVAL;
 525                         goto no_need_xmit;
 526                 }
 527
 528                 switch (ctrlreq->bRequest) {
 529                 case USB_REQ_SET_ADDRESS:
 530                         /* set_address may come when a device is reset */
 531                         dev_info(dev, "SetAddress Request (%d) to port %d\n",
 532                                  ctrlreq->wValue, vdev->rhport);
 533
 534                         if (vdev->udev)
 535                                 usb_put_dev(vdev->udev);
 536                         vdev->udev = usb_get_dev(urb->dev);
 537
 538                         spin_lock(&vdev->ud.lock);
 539                         vdev->ud.status = VDEV_ST_USED;
 540                         spin_unlock(&vdev->ud.lock);
 541
 542                         if (urb->status == -EINPROGRESS) {
 543                                 /* This request is successfully completed. */
 544                                 /* If not -EINPROGRESS, possibly unlinked. */
 545                                 urb->status = 0;
 546                         }
 547
 548                         goto no_need_xmit;
 549
 550                 case USB_REQ_GET_DESCRIPTOR:
 551                         if (ctrlreq->wValue == (USB_DT_DEVICE << 8))
 552                                 usbip_dbg_vhci_hc("Not yet?: "
 553                                                   "Get_Descriptor to device 0 "
 554                                                   "(get max pipe size)\n");
 555
 556                         if (vdev->udev)
 557                                 usb_put_dev(vdev->udev);
 558                         vdev->udev = usb_get_dev(urb->dev);
 559                         goto out;
 560
 561                 default:
 562                         /* NOT REACHED */
 563                         dev_err(dev, "invalid request to devnum 0 bRequest %u, "
 564                                 "wValue %u\n", ctrlreq->bRequest,
 565                                 ctrlreq->wValue);
 566                         ret =  -EINVAL;
 567                         goto no_need_xmit;
 568                 }
 569
 570         }
 571
 572 out:
 573         vhci_tx_urb(urb);
 574         spin_unlock_irqrestore(&the_controller->lock, flags);
 575
 576         return 0;
 577
 578 no_need_xmit:
 579         usb_hcd_unlink_urb_from_ep(hcd, urb);
 580 no_need_unlink:
 581         spin_unlock_irqrestore(&the_controller->lock, flags);
 582         usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
 583         return ret;
 584 }
 585
 586 /*
 587  * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 588  * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 589  * back its urb. For the driver unlinking the urb, the content of the urb is
 590  * not important, but the calling to its completion handler is important; the
 591  * completion of unlinking is notified by the completion handler.
 592  *
 593  *
 594  * CLIENT SIDE
 595  *
 596  * - When vhci_hcd receives RET_SUBMIT,
 597  *
 598  *      - case 1a). the urb of the pdu is not unlinking.
 599  *              - normal case
 600  *              => just give back the urb
 601  *
 602  *      - case 1b). the urb of the pdu is unlinking.
 603  *              - usbip.ko will return a reply of the unlinking request.
 604  *              => give back the urb now and go to case 2b).
 605  *
 606  * - When vhci_hcd receives RET_UNLINK,
 607  *
 608  *      - case 2a). a submit request is still pending in vhci_hcd.
 609  *              - urb was really pending in usbip.ko and urb_unlink_urb() was
 610  *                completed there.
 611  *              => free a pending submit request
 612  *              => notify unlink completeness by giving back the urb
 613  *
 614  *      - case 2b). a submit request is *not* pending in vhci_hcd.
 615  *              - urb was already given back to the core driver.
 616  *              => do not give back the urb
 617  *
 618  *
 619  * SERVER SIDE
 620  *
 621  * - When usbip receives CMD_UNLINK,
 622  *
 623  *      - case 3a). the urb of the unlink request is now in submission.
 624  *              => do usb_unlink_urb().
 625  *              => after the unlink is completed, send RET_UNLINK.
 626  *
 627  *      - case 3b). the urb of the unlink request is not in submission.
 628  *              - may be already completed or never be received
 629  *              => send RET_UNLINK
 630  *
 631  */
 632 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 633 {
 634         unsigned long flags;
 635         struct vhci_priv *priv;
 636         struct vhci_device *vdev;
 637
 638         pr_info("dequeue a urb %p\n", urb);
 639
 640         spin_lock_irqsave(&the_controller->lock, flags);
 641
 642         priv = urb->hcpriv;
 643         if (!priv) {
 644                 /* URB was never linked! or will be soon given back by
 645                  * vhci_rx. */
 646                 spin_unlock_irqrestore(&the_controller->lock, flags);
 647                 return 0;
 648         }
 649
 650         {
 651                 int ret = 0;
 652                 ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 653                 if (ret) {
 654                         spin_unlock_irqrestore(&the_controller->lock, flags);
 655                         return ret;
 656                 }
 657         }
 658
 659          /* send unlink request here? */
 660         vdev = priv->vdev;
 661
 662         if (!vdev->ud.tcp_socket) {
 663                 /* tcp connection is closed */
 664                 unsigned long flags2;
 665
 666                 spin_lock_irqsave(&vdev->priv_lock, flags2);
 667
 668                 pr_info("device %p seems to be disconnected\n", vdev);
 669                 list_del(&priv->list);
 670                 kfree(priv);
 671                 urb->hcpriv = NULL;
 672
 673                 spin_unlock_irqrestore(&vdev->priv_lock, flags2);
 674
 675                 /*
 676                  * If tcp connection is alive, we have sent CMD_UNLINK.
 677                  * vhci_rx will receive RET_UNLINK and give back the URB.
 678                  * Otherwise, we give back it here.
 679                  */
 680                 pr_info("gives back urb %p\n", urb);
 681
 682                 usb_hcd_unlink_urb_from_ep(hcd, urb);
 683
 684                 spin_unlock_irqrestore(&the_controller->lock, flags);
 685                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 686                                      urb->status);
 687                 spin_lock_irqsave(&the_controller->lock, flags);
 688
 689         } else {
 690                 /* tcp connection is alive */
 691                 unsigned long flags2;
 692                 struct vhci_unlink *unlink;
 693
 694                 spin_lock_irqsave(&vdev->priv_lock, flags2);
 695
 696                 /* setup CMD_UNLINK pdu */
 697                 unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 698                 if (!unlink) {
 699                         pr_err("malloc vhci_unlink\n");
 700                         spin_unlock_irqrestore(&vdev->priv_lock, flags2);
 701                         spin_unlock_irqrestore(&the_controller->lock, flags);
 702                         usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 703                         return -ENOMEM;
 704                 }
 705
 706                 unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
 707                 if (unlink->seqnum == 0xffff)
 708                         pr_info("seqnum max\n");
 709
 710                 unlink->unlink_seqnum = priv->seqnum;
 711
 712                 pr_info("device %p seems to be still connected\n", vdev);
 713
 714                 /* send cmd_unlink and try to cancel the pending URB in the
 715                  * peer */
 716                 list_add_tail(&unlink->list, &vdev->unlink_tx);
 717                 wake_up(&vdev->waitq_tx);
 718
 719                 spin_unlock_irqrestore(&vdev->priv_lock, flags2);
 720         }
 721
 722         spin_unlock_irqrestore(&the_controller->lock, flags);
 723
 724         usbip_dbg_vhci_hc("leave\n");
 725         return 0;
 726 }
 727
 728 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 729 {
 730         struct vhci_unlink *unlink, *tmp;
 731
 732         spin_lock(&the_controller->lock);
 733         spin_lock(&vdev->priv_lock);
 734
 735         list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 736                 pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 737                 list_del(&unlink->list);
 738                 kfree(unlink);
 739         }
 740
 741         while (!list_empty(&vdev->unlink_rx)) {
 742                 struct urb *urb;
 743
 744                 unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 745                         list);
 746
 747                 /* give back URB of unanswered unlink request */
 748                 pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 749
 750                 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 751                 if (!urb) {
 752                         pr_info("the urb (seqnum %lu) was already given back\n",
 753                                 unlink->unlink_seqnum);
 754                         list_del(&unlink->list);
 755                         kfree(unlink);
 756                         continue;
 757                 }
 758
 759                 urb->status = -ENODEV;
 760
 761                 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 762
 763                 list_del(&unlink->list);
 764
 765                 spin_unlock(&vdev->priv_lock);
 766                 spin_unlock(&the_controller->lock);
 767
 768                 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 769                                      urb->status);
 770
 771                 spin_lock(&the_controller->lock);
 772                 spin_lock(&vdev->priv_lock);
 773
 774                 kfree(unlink);
 775         }
 776
 777         spin_unlock(&vdev->priv_lock);
 778         spin_unlock(&the_controller->lock);
 779 }
 780
 781 /*
 782  * The important thing is that only one context begins cleanup.
 783  * This is why error handling and cleanup become simple.
 784  * We do not want to consider race condition as possible.
 785  */
 786 static void vhci_shutdown_connection(struct usbip_device *ud)
 787 {
 788         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 789
 790         /* need this? see stub_dev.c */
 791         if (ud->tcp_socket) {
 792                 pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 793                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 794         }
 795
 796         /* kill threads related to this sdev */
 797         if (vdev->ud.tcp_rx) {
 798                 kthread_stop_put(vdev->ud.tcp_rx);
 799                 vdev->ud.tcp_rx = NULL;
 800         }
 801         if (vdev->ud.tcp_tx) {
 802                 kthread_stop_put(vdev->ud.tcp_tx);
 803                 vdev->ud.tcp_tx = NULL;
 804         }
 805         pr_info("stop threads\n");
 806
 807         /* active connection is closed */
 808         if (vdev->ud.tcp_socket) {
 809                 fput(vdev->ud.tcp_socket->file);
 810                 vdev->ud.tcp_socket = NULL;
 811         }
 812         pr_info("release socket\n");
 813
 814         vhci_device_unlink_cleanup(vdev);
 815
 816         /*
 817          * rh_port_disconnect() is a trigger of ...
 818          *   usb_disable_device():
 819          *      disable all the endpoints for a USB device.
 820          *   usb_disable_endpoint():
 821          *      disable endpoints. pending urbs are unlinked(dequeued).
 822          *
 823          * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 824          * detached device should release used urbs in a cleanup function (i.e.
 825          * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 826          * pushed urbs and their private data in this function.
 827          *
 828          * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 829          * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 830          * gives back pushed urbs and frees their private data by request of
 831          * the cleanup function of a USB driver. When unlinking a urb with an
 832          * active connection, vhci_dequeue() does not give back the urb which
 833          * is actually given back by vhci_rx after receiving its return pdu.
 834          *
 835          */
 836         rh_port_disconnect(vdev->rhport);
 837
 838         pr_info("disconnect device\n");
 839 }
 840
 841
 842 static void vhci_device_reset(struct usbip_device *ud)
 843 {
 844         struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 845
 846         spin_lock(&ud->lock);
 847
 848         vdev->speed  = 0;
 849         vdev->devid  = 0;
 850
 851         if (vdev->udev)
 852                 usb_put_dev(vdev->udev);
 853         vdev->udev = NULL;
 854
 855         if (ud->tcp_socket) {
 856                 fput(ud->tcp_socket->file);
 857                 ud->tcp_socket = NULL;
 858         }
 859         ud->status = VDEV_ST_NULL;
 860
 861         spin_unlock(&ud->lock);
 862 }
 863
 864 static void vhci_device_unusable(struct usbip_device *ud)
 865 {
 866         spin_lock(&ud->lock);
 867         ud->status = VDEV_ST_ERROR;
 868         spin_unlock(&ud->lock);
 869 }
 870
 871 static void vhci_device_init(struct vhci_device *vdev)
 872 {
 873         memset(vdev, 0, sizeof(*vdev));
 874
 875         vdev->ud.side   = USBIP_VHCI;
 876         vdev->ud.status = VDEV_ST_NULL;
 877         spin_lock_init(&vdev->ud.lock);
 878
 879         INIT_LIST_HEAD(&vdev->priv_rx);
 880         INIT_LIST_HEAD(&vdev->priv_tx);
 881         INIT_LIST_HEAD(&vdev->unlink_tx);
 882         INIT_LIST_HEAD(&vdev->unlink_rx);
 883         spin_lock_init(&vdev->priv_lock);
 884
 885         init_waitqueue_head(&vdev->waitq_tx);
 886
 887         vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 888         vdev->ud.eh_ops.reset = vhci_device_reset;
 889         vdev->ud.eh_ops.unusable = vhci_device_unusable;
 890
 891         usbip_start_eh(&vdev->ud);
 892 }
 893
 894 static int vhci_start(struct usb_hcd *hcd)
 895 {
 896         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 897         int rhport;
 898         int err = 0;
 899
 900         usbip_dbg_vhci_hc("enter vhci_start\n");
 901
 902         /* initialize private data of usb_hcd */
 903
 904         for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 905                 struct vhci_device *vdev = &vhci->vdev[rhport];
 906                 vhci_device_init(vdev);
 907                 vdev->rhport = rhport;
 908         }
 909
 910         atomic_set(&vhci->seqnum, 0);
 911         spin_lock_init(&vhci->lock);
 912
 913         hcd->power_budget = 0; /* no limit */
 914         hcd->uses_new_polling = 1;
 915
 916         /* vhci_hcd is now ready to be controlled through sysfs */
 917         err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 918         if (err) {
 919                 pr_err("create sysfs files\n");
 920                 return err;
 921         }
 922
 923         return 0;
 924 }
 925
 926 static void vhci_stop(struct usb_hcd *hcd)
 927 {
 928         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 929         int rhport = 0;
 930
 931         usbip_dbg_vhci_hc("stop VHCI controller\n");
 932
 933         /* 1. remove the userland interface of vhci_hcd */
 934         sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 935
 936         /* 2. shutdown all the ports of vhci_hcd */
 937         for (rhport = 0 ; rhport < VHCI_NPORTS; rhport++) {
 938                 struct vhci_device *vdev = &vhci->vdev[rhport];
 939
 940                 usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
 941                 usbip_stop_eh(&vdev->ud);
 942         }
 943 }
 944
 945 static int vhci_get_frame_number(struct usb_hcd *hcd)
 946 {
 947         pr_err("Not yet implemented\n");
 948         return 0;
 949 }
 950
 951 #ifdef CONFIG_PM
 952
 953 /* FIXME: suspend/resume */
 954 static int vhci_bus_suspend(struct usb_hcd *hcd)
 955 {
 956         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 957
 958         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 959
 960         spin_lock_irq(&vhci->lock);
 961         hcd->state = HC_STATE_SUSPENDED;
 962         spin_unlock_irq(&vhci->lock);
 963
 964         return 0;
 965 }
 966
 967 static int vhci_bus_resume(struct usb_hcd *hcd)
 968 {
 969         struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 970         int rc = 0;
 971
 972         dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 973
 974         spin_lock_irq(&vhci->lock);
 975         if (!HCD_HW_ACCESSIBLE(hcd)) {
 976                 rc = -ESHUTDOWN;
 977         } else {
 978                 hcd->state = HC_STATE_RUNNING;
 979         }
 980         spin_unlock_irq(&vhci->lock);
 981
 982         return rc;
 983 }
 984
 985 #else
 986
 987 #define vhci_bus_suspend      NULL
 988 #define vhci_bus_resume       NULL
 989 #endif
 990
 991 static struct hc_driver vhci_hc_driver = {
 992         .description    = driver_name,
 993         .product_desc   = driver_desc,
 994         .hcd_priv_size  = sizeof(struct vhci_hcd),
 995
 996         .flags          = HCD_USB2,
 997
 998         .start          = vhci_start,
 999         .stop           = vhci_stop,
1000
1001         .urb_enqueue    = vhci_urb_enqueue,
1002         .urb_dequeue    = vhci_urb_dequeue,
1003
1004         .get_frame_number = vhci_get_frame_number,
1005
1006         .hub_status_data = vhci_hub_status,
1007         .hub_control    = vhci_hub_control,
1008         .bus_suspend    = vhci_bus_suspend,
1009         .bus_resume     = vhci_bus_resume,
1010 };
1011
1012 static int vhci_hcd_probe(struct platform_device *pdev)
1013 {
1014         struct usb_hcd          *hcd;
1015         int                     ret;
1016
1017         usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1018
1019         /* will be removed */
1020         if (pdev->dev.dma_mask) {
1021                 dev_info(&pdev->dev, "vhci_hcd DMA not supported\n");
1022                 return -EINVAL;
1023         }
1024
1025         /*
1026          * Allocate and initialize hcd.
1027          * Our private data is also allocated automatically.
1028          */
1029         hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1030         if (!hcd) {
1031                 pr_err("create hcd failed\n");
1032                 return -ENOMEM;
1033         }
1034         hcd->has_tt = 1;
1035
1036         /* this is private data for vhci_hcd */
1037         the_controller = hcd_to_vhci(hcd);
1038
1039         /*
1040          * Finish generic HCD structure initialization and register.
1041          * Call the driver's reset() and start() routines.
1042          */
1043         ret = usb_add_hcd(hcd, 0, 0);
1044         if (ret != 0) {
1045                 pr_err("usb_add_hcd failed %d\n", ret);
1046                 usb_put_hcd(hcd);
1047                 the_controller = NULL;
1048                 return ret;
1049         }
1050
1051         usbip_dbg_vhci_hc("bye\n");
1052         return 0;
1053 }
1054
1055 static int vhci_hcd_remove(struct platform_device *pdev)
1056 {
1057         struct usb_hcd  *hcd;
1058
1059         hcd = platform_get_drvdata(pdev);
1060         if (!hcd)
1061                 return 0;
1062
1063         /*
1064          * Disconnects the root hub,
1065          * then reverses the effects of usb_add_hcd(),
1066          * invoking the HCD's stop() methods.
1067          */
1068         usb_remove_hcd(hcd);
1069         usb_put_hcd(hcd);
1070         the_controller = NULL;
1071
1072         return 0;
1073 }
1074
1075 #ifdef CONFIG_PM
1076
1077 /* what should happen for USB/IP under suspend/resume? */
1078 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1079 {
1080         struct usb_hcd *hcd;
1081         int rhport = 0;
1082         int connected = 0;
1083         int ret = 0;
1084
1085         hcd = platform_get_drvdata(pdev);
1086
1087         spin_lock(&the_controller->lock);
1088
1089         for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1090                 if (the_controller->port_status[rhport] &
1091                     USB_PORT_STAT_CONNECTION)
1092                         connected += 1;
1093
1094         spin_unlock(&the_controller->lock);
1095
1096         if (connected > 0) {
1097                 dev_info(&pdev->dev, "We have %d active connection%s. Do not "
1098                          "suspend.\n", connected, (connected == 1 ? "" : "s"));
1099                 ret =  -EBUSY;
1100         } else {
1101                 dev_info(&pdev->dev, "suspend vhci_hcd");
1102                 clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1103         }
1104
1105         return ret;
1106 }
1107
1108 static int vhci_hcd_resume(struct platform_device *pdev)
1109 {
1110         struct usb_hcd *hcd;
1111
1112         dev_dbg(&pdev->dev, "%s\n", __func__);
1113
1114         hcd = platform_get_drvdata(pdev);
1115         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1116         usb_hcd_poll_rh_status(hcd);
1117
1118         return 0;
1119 }
1120
1121 #else
1122
1123 #define vhci_hcd_suspend        NULL
1124 #define vhci_hcd_resume         NULL
1125
1126 #endif
1127
1128 static struct platform_driver vhci_driver = {
1129         .probe  = vhci_hcd_probe,
1130         .remove = vhci_hcd_remove,
1131         .suspend = vhci_hcd_suspend,
1132         .resume = vhci_hcd_resume,
1133         .driver = {
1134                 .name = (char *) driver_name,
1135                 .owner = THIS_MODULE,
1136         },
1137 };
1138
1139 /*
1140  * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1141  * We need to add this virtual device as a platform device arbitrarily:
1142  *      1. platform_device_register()
1143  */
1144 static void the_pdev_release(struct device *dev)
1145 {
1146         return;
1147 }
1148
1149 static struct platform_device the_pdev = {
1150         /* should be the same name as driver_name */
1151         .name = (char *) driver_name,
1152         .id = -1,
1153         .dev = {
1154                 .release = the_pdev_release,
1155         },
1156 };
1157
1158 static int __init vhci_hcd_init(void)
1159 {
1160         int ret;
1161
1162         if (usb_disabled())
1163                 return -ENODEV;
1164
1165         ret = platform_driver_register(&vhci_driver);
1166         if (ret < 0)
1167                 goto err_driver_register;
1168
1169         ret = platform_device_register(&the_pdev);
1170         if (ret < 0)
1171                 goto err_platform_device_register;
1172
1173         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1174         return ret;
1175
1176 err_platform_device_register:
1177         platform_driver_unregister(&vhci_driver);
1178 err_driver_register:
1179         return ret;
1180 }
1181
1182 static void __exit vhci_hcd_exit(void)
1183 {
1184         platform_device_unregister(&the_pdev);
1185         platform_driver_unregister(&vhci_driver);
1186 }
1187
1188 module_init(vhci_hcd_init);
1189 module_exit(vhci_hcd_exit);
1190
1191 MODULE_AUTHOR(DRIVER_AUTHOR);
1192 MODULE_DESCRIPTION(DRIVER_DESC);
1193 MODULE_LICENSE("GPL");
1194 MODULE_VERSION(USBIP_VERSION);