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   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
  46static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
  47static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
  48			    u16 wIndex, char *buff, u16 wLength);
  49static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
  50			    gfp_t mem_flags);
  51static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
  52static int vhci_start(struct usb_hcd *vhci_hcd);
  53static void vhci_stop(struct usb_hcd *hcd);
  54static int vhci_get_frame_number(struct usb_hcd *hcd);
  55
  56static const char driver_name[] = "vhci_hcd";
  57static const char driver_desc[] = "USB/IP Virtual Host Controller";
  58
  59struct vhci_hcd *the_controller;
  60
  61static 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
  96static 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
 122void 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
 149static 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 */
 183static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
 184{
 185	struct vhci_hcd	*vhci;
 186	int		retval;
 187	int		rhport;
 188	int		changed = 0;
 189	unsigned long	flags;
 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	if ((hcd->state == HC_STATE_SUSPENDED) && (changed == 1))
 214		usb_hcd_resume_root_hub(hcd);
 215
 216done:
 217	spin_unlock_irqrestore(&vhci->lock, flags);
 218	return changed ? retval : 0;
 219}
 220
 221static inline void hub_descriptor(struct usb_hub_descriptor *desc)
 222{
 223	memset(desc, 0, sizeof(*desc));
 224	desc->bDescriptorType = USB_DT_HUB;
 225	desc->bDescLength = 9;
 226	desc->wHubCharacteristics = cpu_to_le16(
 227		HUB_CHAR_INDV_PORT_LPSM | HUB_CHAR_COMMON_OCPM);
 228	desc->bNbrPorts = VHCI_NPORTS;
 229	desc->u.hs.DeviceRemovable[0] = 0xff;
 230	desc->u.hs.DeviceRemovable[1] = 0xff;
 231}
 232
 233static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 234			    u16 wIndex, char *buf, u16 wLength)
 235{
 236	struct vhci_hcd	*dum;
 237	int             retval = 0;
 238	int		rhport;
 239	unsigned long	flags;
 240
 241	u32 prev_port_status[VHCI_NPORTS];
 242
 243	if (!HCD_HW_ACCESSIBLE(hcd))
 244		return -ETIMEDOUT;
 245
 246	/*
 247	 * NOTE:
 248	 * wIndex shows the port number and begins from 1.
 249	 */
 250	usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 251			  wIndex);
 252	if (wIndex > VHCI_NPORTS)
 253		pr_err("invalid port number %d\n", wIndex);
 254	rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 255
 256	dum = hcd_to_vhci(hcd);
 257
 258	spin_lock_irqsave(&dum->lock, flags);
 259
 260	/* store old status and compare now and old later */
 261	if (usbip_dbg_flag_vhci_rh) {
 262		memcpy(prev_port_status, dum->port_status,
 263			sizeof(prev_port_status));
 264	}
 265
 266	switch (typeReq) {
 267	case ClearHubFeature:
 268		usbip_dbg_vhci_rh(" ClearHubFeature\n");
 269		break;
 270	case ClearPortFeature:
 271		switch (wValue) {
 272		case USB_PORT_FEAT_SUSPEND:
 273			if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
 274				/* 20msec signaling */
 275				dum->resuming = 1;
 276				dum->re_timeout =
 277					jiffies + msecs_to_jiffies(20);
 278			}
 279			break;
 280		case USB_PORT_FEAT_POWER:
 281			usbip_dbg_vhci_rh(
 282				" ClearPortFeature: USB_PORT_FEAT_POWER\n");
 283			dum->port_status[rhport] = 0;
 284			dum->resuming = 0;
 285			break;
 286		case USB_PORT_FEAT_C_RESET:
 287			usbip_dbg_vhci_rh(
 288				" ClearPortFeature: USB_PORT_FEAT_C_RESET\n");
 289			switch (dum->vdev[rhport].speed) {
 290			case USB_SPEED_HIGH:
 291				dum->port_status[rhport] |=
 292					USB_PORT_STAT_HIGH_SPEED;
 293				break;
 294			case USB_SPEED_LOW:
 295				dum->port_status[rhport] |=
 296					USB_PORT_STAT_LOW_SPEED;
 297				break;
 298			default:
 299				break;
 300			}
 301		default:
 302			usbip_dbg_vhci_rh(" ClearPortFeature: default %x\n",
 303					  wValue);
 304			dum->port_status[rhport] &= ~(1 << wValue);
 305			break;
 306		}
 307		break;
 308	case GetHubDescriptor:
 309		usbip_dbg_vhci_rh(" GetHubDescriptor\n");
 310		hub_descriptor((struct usb_hub_descriptor *) buf);
 311		break;
 312	case GetHubStatus:
 313		usbip_dbg_vhci_rh(" GetHubStatus\n");
 314		*(__le32 *) buf = cpu_to_le32(0);
 315		break;
 316	case GetPortStatus:
 317		usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
 318		if (wIndex > VHCI_NPORTS || wIndex < 1) {
 319			pr_err("invalid port number %d\n", wIndex);
 320			retval = -EPIPE;
 321		}
 322
 323		/* we do not care about resume. */
 324
 325		/* whoever resets or resumes must GetPortStatus to
 326		 * complete it!!
 327		 */
 328		if (dum->resuming && time_after(jiffies, dum->re_timeout)) {
 329			dum->port_status[rhport] |=
 330				(1 << USB_PORT_FEAT_C_SUSPEND);
 331			dum->port_status[rhport] &=
 332				~(1 << USB_PORT_FEAT_SUSPEND);
 333			dum->resuming = 0;
 334			dum->re_timeout = 0;
 335		}
 336
 337		if ((dum->port_status[rhport] & (1 << USB_PORT_FEAT_RESET)) !=
 338		    0 && time_after(jiffies, dum->re_timeout)) {
 339			dum->port_status[rhport] |=
 340				(1 << USB_PORT_FEAT_C_RESET);
 341			dum->port_status[rhport] &=
 342				~(1 << USB_PORT_FEAT_RESET);
 343			dum->re_timeout = 0;
 344
 345			if (dum->vdev[rhport].ud.status ==
 346			    VDEV_ST_NOTASSIGNED) {
 347				usbip_dbg_vhci_rh(
 348					" enable rhport %d (status %u)\n",
 349					rhport,
 350					dum->vdev[rhport].ud.status);
 351				dum->port_status[rhport] |=
 352					USB_PORT_STAT_ENABLE;
 353			}
 354		}
 355		((__le16 *) buf)[0] = cpu_to_le16(dum->port_status[rhport]);
 356		((__le16 *) buf)[1] =
 357			cpu_to_le16(dum->port_status[rhport] >> 16);
 358
 359		usbip_dbg_vhci_rh(" GetPortStatus bye %x %x\n", ((u16 *)buf)[0],
 360				  ((u16 *)buf)[1]);
 361		break;
 362	case SetHubFeature:
 363		usbip_dbg_vhci_rh(" SetHubFeature\n");
 364		retval = -EPIPE;
 365		break;
 366	case SetPortFeature:
 367		switch (wValue) {
 368		case USB_PORT_FEAT_SUSPEND:
 369			usbip_dbg_vhci_rh(
 370				" SetPortFeature: USB_PORT_FEAT_SUSPEND\n");
 371			break;
 372		case USB_PORT_FEAT_RESET:
 373			usbip_dbg_vhci_rh(
 374				" SetPortFeature: USB_PORT_FEAT_RESET\n");
 375			/* if it's already running, disconnect first */
 376			if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
 377				dum->port_status[rhport] &=
 378					~(USB_PORT_STAT_ENABLE |
 379					  USB_PORT_STAT_LOW_SPEED |
 380					  USB_PORT_STAT_HIGH_SPEED);
 381				/* FIXME test that code path! */
 382			}
 383			/* 50msec reset signaling */
 384			dum->re_timeout = jiffies + msecs_to_jiffies(50);
 385
 386			/* FALLTHROUGH */
 387		default:
 388			usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
 389					  wValue);
 390			dum->port_status[rhport] |= (1 << wValue);
 391			break;
 392		}
 393		break;
 394
 395	default:
 396		pr_err("default: no such request\n");
 397
 398		/* "protocol stall" on error */
 399		retval = -EPIPE;
 400	}
 401
 402	if (usbip_dbg_flag_vhci_rh) {
 403		pr_debug("port %d\n", rhport);
 404		/* Only dump valid port status */
 405		if (rhport >= 0) {
 406			dump_port_status_diff(prev_port_status[rhport],
 407					      dum->port_status[rhport]);
 408		}
 409	}
 410	usbip_dbg_vhci_rh(" bye\n");
 411
 412	spin_unlock_irqrestore(&dum->lock, flags);
 413
 414	return retval;
 415}
 416
 417static struct vhci_device *get_vdev(struct usb_device *udev)
 418{
 419	int i;
 420
 421	if (!udev)
 422		return NULL;
 423
 424	for (i = 0; i < VHCI_NPORTS; i++)
 425		if (the_controller->vdev[i].udev == udev)
 426			return port_to_vdev(i);
 427
 428	return NULL;
 429}
 430
 431static void vhci_tx_urb(struct urb *urb)
 432{
 433	struct vhci_device *vdev = get_vdev(urb->dev);
 434	struct vhci_priv *priv;
 435	unsigned long flags;
 436
 437	if (!vdev) {
 438		pr_err("could not get virtual device");
 439		return;
 440	}
 441
 442	priv = kzalloc(sizeof(struct vhci_priv), GFP_ATOMIC);
 443	if (!priv) {
 444		usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 445		return;
 446	}
 447
 448	spin_lock_irqsave(&vdev->priv_lock, flags);
 449
 450	priv->seqnum = atomic_inc_return(&the_controller->seqnum);
 451	if (priv->seqnum == 0xffff)
 452		dev_info(&urb->dev->dev, "seqnum max\n");
 453
 454	priv->vdev = vdev;
 455	priv->urb = urb;
 456
 457	urb->hcpriv = (void *) priv;
 458
 459	list_add_tail(&priv->list, &vdev->priv_tx);
 460
 461	wake_up(&vdev->waitq_tx);
 462	spin_unlock_irqrestore(&vdev->priv_lock, flags);
 463}
 464
 465static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 466			    gfp_t mem_flags)
 467{
 468	struct device *dev = &urb->dev->dev;
 469	int ret = 0;
 470	struct vhci_device *vdev;
 471	unsigned long flags;
 472
 473	usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
 474			  hcd, urb, mem_flags);
 475
 476	/* patch to usb_sg_init() is in 2.5.60 */
 477	BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 478
 479	spin_lock_irqsave(&the_controller->lock, flags);
 480
 481	if (urb->status != -EINPROGRESS) {
 482		dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
 483		spin_unlock_irqrestore(&the_controller->lock, flags);
 484		return urb->status;
 485	}
 486
 487	vdev = port_to_vdev(urb->dev->portnum-1);
 488
 489	/* refuse enqueue for dead connection */
 490	spin_lock(&vdev->ud.lock);
 491	if (vdev->ud.status == VDEV_ST_NULL ||
 492	    vdev->ud.status == VDEV_ST_ERROR) {
 493		dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 494		spin_unlock(&vdev->ud.lock);
 495		spin_unlock_irqrestore(&the_controller->lock, flags);
 496		return -ENODEV;
 497	}
 498	spin_unlock(&vdev->ud.lock);
 499
 500	ret = usb_hcd_link_urb_to_ep(hcd, urb);
 501	if (ret)
 502		goto no_need_unlink;
 503
 504	/*
 505	 * The enumeration process is as follows;
 506	 *
 507	 *  1. Get_Descriptor request to DevAddrs(0) EndPoint(0)
 508	 *     to get max packet length of default pipe
 509	 *
 510	 *  2. Set_Address request to DevAddr(0) EndPoint(0)
 511	 *
 512	 */
 513	if (usb_pipedevice(urb->pipe) == 0) {
 514		__u8 type = usb_pipetype(urb->pipe);
 515		struct usb_ctrlrequest *ctrlreq =
 516			(struct usb_ctrlrequest *) urb->setup_packet;
 517
 518		if (type != PIPE_CONTROL || !ctrlreq) {
 519			dev_err(dev, "invalid request to devnum 0\n");
 520			ret = -EINVAL;
 521			goto no_need_xmit;
 522		}
 523
 524		switch (ctrlreq->bRequest) {
 525		case USB_REQ_SET_ADDRESS:
 526			/* set_address may come when a device is reset */
 527			dev_info(dev, "SetAddress Request (%d) to port %d\n",
 528				 ctrlreq->wValue, vdev->rhport);
 529
 530			usb_put_dev(vdev->udev);
 531			vdev->udev = usb_get_dev(urb->dev);
 532
 533			spin_lock(&vdev->ud.lock);
 534			vdev->ud.status = VDEV_ST_USED;
 535			spin_unlock(&vdev->ud.lock);
 536
 537			if (urb->status == -EINPROGRESS) {
 538				/* This request is successfully completed. */
 539				/* If not -EINPROGRESS, possibly unlinked. */
 540				urb->status = 0;
 541			}
 542
 543			goto no_need_xmit;
 544
 545		case USB_REQ_GET_DESCRIPTOR:
 546			if (ctrlreq->wValue == cpu_to_le16(USB_DT_DEVICE << 8))
 547				usbip_dbg_vhci_hc(
 548					"Not yet?:Get_Descriptor to device 0 (get max pipe size)\n");
 549
 550			usb_put_dev(vdev->udev);
 551			vdev->udev = usb_get_dev(urb->dev);
 552			goto out;
 553
 554		default:
 555			/* NOT REACHED */
 556			dev_err(dev,
 557				"invalid request to devnum 0 bRequest %u, wValue %u\n",
 558				ctrlreq->bRequest,
 559				ctrlreq->wValue);
 560			ret =  -EINVAL;
 561			goto no_need_xmit;
 562		}
 563
 564	}
 565
 566out:
 567	vhci_tx_urb(urb);
 568	spin_unlock_irqrestore(&the_controller->lock, flags);
 569
 570	return 0;
 571
 572no_need_xmit:
 573	usb_hcd_unlink_urb_from_ep(hcd, urb);
 574no_need_unlink:
 575	spin_unlock_irqrestore(&the_controller->lock, flags);
 576	if (!ret)
 577		usb_hcd_giveback_urb(vhci_to_hcd(the_controller),
 578				     urb, urb->status);
 579	return ret;
 580}
 581
 582/*
 583 * vhci_rx gives back the urb after receiving the reply of the urb.  If an
 584 * unlink pdu is sent or not, vhci_rx receives a normal return pdu and gives
 585 * back its urb. For the driver unlinking the urb, the content of the urb is
 586 * not important, but the calling to its completion handler is important; the
 587 * completion of unlinking is notified by the completion handler.
 588 *
 589 *
 590 * CLIENT SIDE
 591 *
 592 * - When vhci_hcd receives RET_SUBMIT,
 593 *
 594 *	- case 1a). the urb of the pdu is not unlinking.
 595 *		- normal case
 596 *		=> just give back the urb
 597 *
 598 *	- case 1b). the urb of the pdu is unlinking.
 599 *		- usbip.ko will return a reply of the unlinking request.
 600 *		=> give back the urb now and go to case 2b).
 601 *
 602 * - When vhci_hcd receives RET_UNLINK,
 603 *
 604 *	- case 2a). a submit request is still pending in vhci_hcd.
 605 *		- urb was really pending in usbip.ko and urb_unlink_urb() was
 606 *		  completed there.
 607 *		=> free a pending submit request
 608 *		=> notify unlink completeness by giving back the urb
 609 *
 610 *	- case 2b). a submit request is *not* pending in vhci_hcd.
 611 *		- urb was already given back to the core driver.
 612 *		=> do not give back the urb
 613 *
 614 *
 615 * SERVER SIDE
 616 *
 617 * - When usbip receives CMD_UNLINK,
 618 *
 619 *	- case 3a). the urb of the unlink request is now in submission.
 620 *		=> do usb_unlink_urb().
 621 *		=> after the unlink is completed, send RET_UNLINK.
 622 *
 623 *	- case 3b). the urb of the unlink request is not in submission.
 624 *		- may be already completed or never be received
 625 *		=> send RET_UNLINK
 626 *
 627 */
 628static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 629{
 630	struct vhci_priv *priv;
 631	struct vhci_device *vdev;
 632	unsigned long flags;
 633
 634	pr_info("dequeue a urb %p\n", urb);
 635
 636	spin_lock_irqsave(&the_controller->lock, flags);
 637
 638	priv = urb->hcpriv;
 639	if (!priv) {
 640		/* URB was never linked! or will be soon given back by
 641		 * vhci_rx. */
 642		spin_unlock_irqrestore(&the_controller->lock, flags);
 643		return -EIDRM;
 644	}
 645
 646	{
 647		int ret = 0;
 648
 649		ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 650		if (ret) {
 651			spin_unlock_irqrestore(&the_controller->lock, flags);
 652			return ret;
 653		}
 654	}
 655
 656	 /* send unlink request here? */
 657	vdev = priv->vdev;
 658
 659	if (!vdev->ud.tcp_socket) {
 660		/* tcp connection is closed */
 661		spin_lock(&vdev->priv_lock);
 662
 663		pr_info("device %p seems to be disconnected\n", vdev);
 664		list_del(&priv->list);
 665		kfree(priv);
 666		urb->hcpriv = NULL;
 667
 668		spin_unlock(&vdev->priv_lock);
 669
 670		/*
 671		 * If tcp connection is alive, we have sent CMD_UNLINK.
 672		 * vhci_rx will receive RET_UNLINK and give back the URB.
 673		 * Otherwise, we give back it here.
 674		 */
 675		pr_info("gives back urb %p\n", urb);
 676
 677		usb_hcd_unlink_urb_from_ep(hcd, urb);
 678
 679		spin_unlock_irqrestore(&the_controller->lock, flags);
 680		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 681				     urb->status);
 682		spin_lock_irqsave(&the_controller->lock, flags);
 683
 684	} else {
 685		/* tcp connection is alive */
 686		struct vhci_unlink *unlink;
 687
 688		spin_lock(&vdev->priv_lock);
 689
 690		/* setup CMD_UNLINK pdu */
 691		unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 692		if (!unlink) {
 693			spin_unlock(&vdev->priv_lock);
 694			spin_unlock_irqrestore(&the_controller->lock, flags);
 695			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 696			return -ENOMEM;
 697		}
 698
 699		unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
 700		if (unlink->seqnum == 0xffff)
 701			pr_info("seqnum max\n");
 702
 703		unlink->unlink_seqnum = priv->seqnum;
 704
 705		pr_info("device %p seems to be still connected\n", vdev);
 706
 707		/* send cmd_unlink and try to cancel the pending URB in the
 708		 * peer */
 709		list_add_tail(&unlink->list, &vdev->unlink_tx);
 710		wake_up(&vdev->waitq_tx);
 711
 712		spin_unlock(&vdev->priv_lock);
 713	}
 714
 715	spin_unlock_irqrestore(&the_controller->lock, flags);
 716
 717	usbip_dbg_vhci_hc("leave\n");
 718	return 0;
 719}
 720
 721static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 722{
 723	struct vhci_unlink *unlink, *tmp;
 724	unsigned long flags;
 725
 726	spin_lock_irqsave(&the_controller->lock, flags);
 727	spin_lock(&vdev->priv_lock);
 728
 729	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
 730		pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum);
 731		list_del(&unlink->list);
 732		kfree(unlink);
 733	}
 734
 735	while (!list_empty(&vdev->unlink_rx)) {
 736		struct urb *urb;
 737
 738		unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink,
 739			list);
 740
 741		/* give back URB of unanswered unlink request */
 742		pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum);
 743
 744		urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 745		if (!urb) {
 746			pr_info("the urb (seqnum %lu) was already given back\n",
 747				unlink->unlink_seqnum);
 748			list_del(&unlink->list);
 749			kfree(unlink);
 750			continue;
 751		}
 752
 753		urb->status = -ENODEV;
 754
 755		usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
 756
 757		list_del(&unlink->list);
 758
 759		spin_unlock(&vdev->priv_lock);
 760		spin_unlock_irqrestore(&the_controller->lock, flags);
 761
 762		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
 763				     urb->status);
 764
 765		spin_lock_irqsave(&the_controller->lock, flags);
 766		spin_lock(&vdev->priv_lock);
 767
 768		kfree(unlink);
 769	}
 770
 771	spin_unlock(&vdev->priv_lock);
 772	spin_unlock_irqrestore(&the_controller->lock, flags);
 773}
 774
 775/*
 776 * The important thing is that only one context begins cleanup.
 777 * This is why error handling and cleanup become simple.
 778 * We do not want to consider race condition as possible.
 779 */
 780static void vhci_shutdown_connection(struct usbip_device *ud)
 781{
 782	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 783
 784	/* need this? see stub_dev.c */
 785	if (ud->tcp_socket) {
 786		pr_debug("shutdown tcp_socket %p\n", ud->tcp_socket);
 787		kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 788	}
 789
 790	/* kill threads related to this sdev */
 791	if (vdev->ud.tcp_rx) {
 792		kthread_stop_put(vdev->ud.tcp_rx);
 793		vdev->ud.tcp_rx = NULL;
 794	}
 795	if (vdev->ud.tcp_tx) {
 796		kthread_stop_put(vdev->ud.tcp_tx);
 797		vdev->ud.tcp_tx = NULL;
 798	}
 799	pr_info("stop threads\n");
 800
 801	/* active connection is closed */
 802	if (vdev->ud.tcp_socket) {
 803		sockfd_put(vdev->ud.tcp_socket);
 804		vdev->ud.tcp_socket = NULL;
 805	}
 806	pr_info("release socket\n");
 807
 808	vhci_device_unlink_cleanup(vdev);
 809
 810	/*
 811	 * rh_port_disconnect() is a trigger of ...
 812	 *   usb_disable_device():
 813	 *	disable all the endpoints for a USB device.
 814	 *   usb_disable_endpoint():
 815	 *	disable endpoints. pending urbs are unlinked(dequeued).
 816	 *
 817	 * NOTE: After calling rh_port_disconnect(), the USB device drivers of a
 818	 * detached device should release used urbs in a cleanup function (i.e.
 819	 * xxx_disconnect()). Therefore, vhci_hcd does not need to release
 820	 * pushed urbs and their private data in this function.
 821	 *
 822	 * NOTE: vhci_dequeue() must be considered carefully. When shutting down
 823	 * a connection, vhci_shutdown_connection() expects vhci_dequeue()
 824	 * gives back pushed urbs and frees their private data by request of
 825	 * the cleanup function of a USB driver. When unlinking a urb with an
 826	 * active connection, vhci_dequeue() does not give back the urb which
 827	 * is actually given back by vhci_rx after receiving its return pdu.
 828	 *
 829	 */
 830	rh_port_disconnect(vdev->rhport);
 831
 832	pr_info("disconnect device\n");
 833}
 834
 835
 836static void vhci_device_reset(struct usbip_device *ud)
 837{
 838	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
 839	unsigned long flags;
 840
 841	spin_lock_irqsave(&ud->lock, flags);
 842
 843	vdev->speed  = 0;
 844	vdev->devid  = 0;
 845
 846	usb_put_dev(vdev->udev);
 847	vdev->udev = NULL;
 848
 849	if (ud->tcp_socket) {
 850		sockfd_put(ud->tcp_socket);
 851		ud->tcp_socket = NULL;
 852	}
 853	ud->status = VDEV_ST_NULL;
 854
 855	spin_unlock_irqrestore(&ud->lock, flags);
 856}
 857
 858static void vhci_device_unusable(struct usbip_device *ud)
 859{
 860	unsigned long flags;
 861
 862	spin_lock_irqsave(&ud->lock, flags);
 863	ud->status = VDEV_ST_ERROR;
 864	spin_unlock_irqrestore(&ud->lock, flags);
 865}
 866
 867static void vhci_device_init(struct vhci_device *vdev)
 868{
 869	memset(vdev, 0, sizeof(*vdev));
 870
 871	vdev->ud.side   = USBIP_VHCI;
 872	vdev->ud.status = VDEV_ST_NULL;
 873	spin_lock_init(&vdev->ud.lock);
 874
 875	INIT_LIST_HEAD(&vdev->priv_rx);
 876	INIT_LIST_HEAD(&vdev->priv_tx);
 877	INIT_LIST_HEAD(&vdev->unlink_tx);
 878	INIT_LIST_HEAD(&vdev->unlink_rx);
 879	spin_lock_init(&vdev->priv_lock);
 880
 881	init_waitqueue_head(&vdev->waitq_tx);
 882
 883	vdev->ud.eh_ops.shutdown = vhci_shutdown_connection;
 884	vdev->ud.eh_ops.reset = vhci_device_reset;
 885	vdev->ud.eh_ops.unusable = vhci_device_unusable;
 886
 887	usbip_start_eh(&vdev->ud);
 888}
 889
 890static int vhci_start(struct usb_hcd *hcd)
 891{
 892	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 893	int rhport;
 894	int err = 0;
 895
 896	usbip_dbg_vhci_hc("enter vhci_start\n");
 897
 898	/* initialize private data of usb_hcd */
 899
 900	for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 901		struct vhci_device *vdev = &vhci->vdev[rhport];
 902
 903		vhci_device_init(vdev);
 904		vdev->rhport = rhport;
 905	}
 906
 907	atomic_set(&vhci->seqnum, 0);
 908	spin_lock_init(&vhci->lock);
 909
 910	hcd->power_budget = 0; /* no limit */
 911	hcd->uses_new_polling = 1;
 912
 913	/* vhci_hcd is now ready to be controlled through sysfs */
 914	err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 915	if (err) {
 916		pr_err("create sysfs files\n");
 917		return err;
 918	}
 919
 920	return 0;
 921}
 922
 923static void vhci_stop(struct usb_hcd *hcd)
 924{
 925	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 926	int rhport = 0;
 927
 928	usbip_dbg_vhci_hc("stop VHCI controller\n");
 929
 930	/* 1. remove the userland interface of vhci_hcd */
 931	sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
 932
 933	/* 2. shutdown all the ports of vhci_hcd */
 934	for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
 935		struct vhci_device *vdev = &vhci->vdev[rhport];
 936
 937		usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
 938		usbip_stop_eh(&vdev->ud);
 939	}
 940}
 941
 942static int vhci_get_frame_number(struct usb_hcd *hcd)
 943{
 944	pr_err("Not yet implemented\n");
 945	return 0;
 946}
 947
 948#ifdef CONFIG_PM
 949
 950/* FIXME: suspend/resume */
 951static int vhci_bus_suspend(struct usb_hcd *hcd)
 952{
 953	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 954	unsigned long flags;
 955
 956	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 957
 958	spin_lock_irqsave(&vhci->lock, flags);
 959	hcd->state = HC_STATE_SUSPENDED;
 960	spin_unlock_irqrestore(&vhci->lock, flags);
 961
 962	return 0;
 963}
 964
 965static int vhci_bus_resume(struct usb_hcd *hcd)
 966{
 967	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 968	int rc = 0;
 969	unsigned long flags;
 970
 971	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 972
 973	spin_lock_irqsave(&vhci->lock, flags);
 974	if (!HCD_HW_ACCESSIBLE(hcd))
 975		rc = -ESHUTDOWN;
 976	else
 977		hcd->state = HC_STATE_RUNNING;
 978	spin_unlock_irqrestore(&vhci->lock, flags);
 979
 980	return rc;
 981}
 982
 983#else
 984
 985#define vhci_bus_suspend      NULL
 986#define vhci_bus_resume       NULL
 987#endif
 988
 989static struct hc_driver vhci_hc_driver = {
 990	.description	= driver_name,
 991	.product_desc	= driver_desc,
 992	.hcd_priv_size	= sizeof(struct vhci_hcd),
 993
 994	.flags		= HCD_USB2,
 995
 996	.start		= vhci_start,
 997	.stop		= vhci_stop,
 998
 999	.urb_enqueue	= vhci_urb_enqueue,
1000	.urb_dequeue	= vhci_urb_dequeue,
1001
1002	.get_frame_number = vhci_get_frame_number,
1003
1004	.hub_status_data = vhci_hub_status,
1005	.hub_control    = vhci_hub_control,
1006	.bus_suspend	= vhci_bus_suspend,
1007	.bus_resume	= vhci_bus_resume,
1008};
1009
1010static int vhci_hcd_probe(struct platform_device *pdev)
1011{
1012	struct usb_hcd		*hcd;
1013	int			ret;
1014
1015	usbip_dbg_vhci_hc("name %s id %d\n", pdev->name, pdev->id);
1016
1017	/*
1018	 * Allocate and initialize hcd.
1019	 * Our private data is also allocated automatically.
1020	 */
1021	hcd = usb_create_hcd(&vhci_hc_driver, &pdev->dev, dev_name(&pdev->dev));
1022	if (!hcd) {
1023		pr_err("create hcd failed\n");
1024		return -ENOMEM;
1025	}
1026	hcd->has_tt = 1;
1027
1028	/* this is private data for vhci_hcd */
1029	the_controller = hcd_to_vhci(hcd);
1030
1031	/*
1032	 * Finish generic HCD structure initialization and register.
1033	 * Call the driver's reset() and start() routines.
1034	 */
1035	ret = usb_add_hcd(hcd, 0, 0);
1036	if (ret != 0) {
1037		pr_err("usb_add_hcd failed %d\n", ret);
1038		usb_put_hcd(hcd);
1039		the_controller = NULL;
1040		return ret;
1041	}
1042
1043	usbip_dbg_vhci_hc("bye\n");
1044	return 0;
1045}
1046
1047static int vhci_hcd_remove(struct platform_device *pdev)
1048{
1049	struct usb_hcd	*hcd;
1050
1051	hcd = platform_get_drvdata(pdev);
1052	if (!hcd)
1053		return 0;
1054
1055	/*
1056	 * Disconnects the root hub,
1057	 * then reverses the effects of usb_add_hcd(),
1058	 * invoking the HCD's stop() methods.
1059	 */
1060	usb_remove_hcd(hcd);
1061	usb_put_hcd(hcd);
1062	the_controller = NULL;
1063
1064	return 0;
1065}
1066
1067#ifdef CONFIG_PM
1068
1069/* what should happen for USB/IP under suspend/resume? */
1070static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
1071{
1072	struct usb_hcd *hcd;
1073	int rhport = 0;
1074	int connected = 0;
1075	int ret = 0;
1076	unsigned long flags;
1077
1078	hcd = platform_get_drvdata(pdev);
1079
1080	spin_lock_irqsave(&the_controller->lock, flags);
1081
1082	for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
1083		if (the_controller->port_status[rhport] &
1084		    USB_PORT_STAT_CONNECTION)
1085			connected += 1;
1086
1087	spin_unlock_irqrestore(&the_controller->lock, flags);
1088
1089	if (connected > 0) {
1090		dev_info(&pdev->dev,
1091			 "We have %d active connection%s. Do not suspend.\n",
1092			 connected, (connected == 1 ? "" : "s"));
1093		ret =  -EBUSY;
1094	} else {
1095		dev_info(&pdev->dev, "suspend vhci_hcd");
1096		clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1097	}
1098
1099	return ret;
1100}
1101
1102static int vhci_hcd_resume(struct platform_device *pdev)
1103{
1104	struct usb_hcd *hcd;
1105
1106	dev_dbg(&pdev->dev, "%s\n", __func__);
1107
1108	hcd = platform_get_drvdata(pdev);
1109	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
1110	usb_hcd_poll_rh_status(hcd);
1111
1112	return 0;
1113}
1114
1115#else
1116
1117#define vhci_hcd_suspend	NULL
1118#define vhci_hcd_resume		NULL
1119
1120#endif
1121
1122static struct platform_driver vhci_driver = {
1123	.probe	= vhci_hcd_probe,
1124	.remove	= vhci_hcd_remove,
1125	.suspend = vhci_hcd_suspend,
1126	.resume	= vhci_hcd_resume,
1127	.driver	= {
1128		.name = driver_name,
1129	},
1130};
1131
1132/*
1133 * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
1134 * We need to add this virtual device as a platform device arbitrarily:
1135 *	1. platform_device_register()
1136 */
1137static void the_pdev_release(struct device *dev)
1138{
1139}
1140
1141static struct platform_device the_pdev = {
1142	/* should be the same name as driver_name */
1143	.name = driver_name,
1144	.id = -1,
1145	.dev = {
1146		.release = the_pdev_release,
1147	},
1148};
1149
1150static int __init vhci_hcd_init(void)
1151{
1152	int ret;
1153
1154	if (usb_disabled())
1155		return -ENODEV;
1156
1157	ret = platform_driver_register(&vhci_driver);
1158	if (ret)
1159		goto err_driver_register;
1160
1161	ret = platform_device_register(&the_pdev);
1162	if (ret)
1163		goto err_platform_device_register;
1164
1165	pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
1166	return ret;
1167
1168err_platform_device_register:
1169	platform_driver_unregister(&vhci_driver);
1170err_driver_register:
1171	return ret;
1172}
1173
1174static void __exit vhci_hcd_exit(void)
1175{
1176	platform_device_unregister(&the_pdev);
1177	platform_driver_unregister(&vhci_driver);
1178}
1179
1180module_init(vhci_hcd_init);
1181module_exit(vhci_hcd_exit);
1182
1183MODULE_AUTHOR(DRIVER_AUTHOR);
1184MODULE_DESCRIPTION(DRIVER_DESC);
1185MODULE_LICENSE("GPL");
1186MODULE_VERSION(USBIP_VERSION);