drivers/usb/usbip/vhci_hcd.c

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