usbip: vhci extension: modifications to vhci driver

Modification to Kconfig, vhci_hc.c, vhci.h and vhci_sysfs.c.

1. kernel config

Followings are added.

USBIP_VHCI_HC_PORTS: Number of ports per USB/IP virtual host
controller. The default is 8 - same as current VHCI_NPORTS.
USBIP_VHCI_NR_HCS: Number of USB/IP virtual host controllers. The
default is 1. This paratmeter is replaced with USBIP_VHCI_INIT_HCS and
USBIP_VHCI_MAX_HCS included in succeeding dynamic extension patch.

2. the_controller to controllers

the_controller is changed to vhci_pdevs: array of struct
platform_device.

3. vhci_sysfs.c

Sysfs structure is changed as following.

BEFORE:
    /sys/devices/platform
        +-- vhci
            +-- status
            +-- attach
            +-- detach
            +-- usbip_debug

AFTER: example for CONFIG_USBIP_NR_HCS=4
    /sys/devices/platform
        +-- vhci
        |   +-- nports
        |   +-- status
        |   +-- status.1
        |   +-- status.2
        |   +-- status.3
        |   +-- attach
        |   +-- detach
        |   +-- usbip_debug
        +-- vhci.1
        +-- vhci.2
        +-- vhci.3

vhci[.N] is shown for each host controller kobj. vhch.1, vhci.2, ...
are shown only when CONFIG_USBIP_NR_HCS is more than 1. Only 'vhci'
(without number) has user space interfaces. 'nports' is newly added to
give ports-per-controller and number of controlles. Before that, number
of ports is acquired by reading status lines. Status is divided for
each controller to avoid page size (4KB) limitation.

Old userspace tool binaries work with the first status within the first
controller.

Inconsistency between status header and content is fixed.
4th and 5th column are
header:          "dev bus"
content(unused): "000 000"
content(used):   "%08x", devid
Only 1st and 2nd column are used by program. In old version, sscanf()
in parse_status expect no bus column. And bus_id string is shown in the
last column. Then bus in the header is removed and unused content is
replaced with 8 zeros. The sscanf() expects more than 5 columns and new
has 6 columns so there's no compatibility issue in this change.

Signed-off-by: Nobuo Iwata <nobuo.iwata@fujixerox.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 191 insertions, 94 deletions

diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index 2e0450bec1b1..96f2dacb27fa 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ * Copyright (C) 2015-2016 Nobuo Iwata
  *
  * This is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -56,7 +57,9 @@ static int vhci_get_frame_number(struct usb_hcd *hcd);
 static const char driver_name[] = "vhci_hcd";
 static const char driver_desc[] = "USB/IP Virtual Host Controller";
 
-struct vhci_hcd *the_controller;
+int vhci_num_controllers = VHCI_NR_HCS;
+
+struct platform_device **vhci_pdevs;
 
 static const char * const bit_desc[] = {
 	"CONNECTION",		/*0*/
@@ -119,47 +122,59 @@ static void dump_port_status_diff(u32 prev_status, u32 new_status)
 	pr_debug("\n");
 }
 
-void rh_port_connect(int rhport, enum usb_device_speed speed)
+void rh_port_connect(struct vhci_device *vdev, enum usb_device_speed speed)
 {
+	struct vhci_hcd	*vhci = vdev_to_vhci(vdev);
+	int		rhport = vdev->rhport;
+	u32		status;
 	unsigned long	flags;
 
 	usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
 
-	spin_lock_irqsave(&the_controller->lock, flags);
+	spin_lock_irqsave(&vhci->lock, flags);
+
+	status = vhci->port_status[rhport];
 
-	the_controller->port_status[rhport] |= USB_PORT_STAT_CONNECTION
-		| (1 << USB_PORT_FEAT_C_CONNECTION);
+	status |= USB_PORT_STAT_CONNECTION | (1 << USB_PORT_FEAT_C_CONNECTION);
 
 	switch (speed) {
 	case USB_SPEED_HIGH:
-		the_controller->port_status[rhport] |= USB_PORT_STAT_HIGH_SPEED;
+		status |= USB_PORT_STAT_HIGH_SPEED;
 		break;
 	case USB_SPEED_LOW:
-		the_controller->port_status[rhport] |= USB_PORT_STAT_LOW_SPEED;
+		status |= USB_PORT_STAT_LOW_SPEED;
 		break;
 	default:
 		break;
 	}
 
-	spin_unlock_irqrestore(&the_controller->lock, flags);
+	vhci->port_status[rhport] = status;
+
+	spin_unlock_irqrestore(&vhci->lock, flags);
 
-	usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
+	usb_hcd_poll_rh_status(vhci_to_hcd(vhci));
 }
 
-static void rh_port_disconnect(int rhport)
+static void rh_port_disconnect(struct vhci_device *vdev)
 {
+	struct vhci_hcd	*vhci = vdev_to_vhci(vdev);
+	int		rhport = vdev->rhport;
+	u32		status;
 	unsigned long	flags;
 
 	usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
 
-	spin_lock_irqsave(&the_controller->lock, flags);
+	spin_lock_irqsave(&vhci->lock, flags);
+
+	status = vhci->port_status[rhport];
+
+	status &= ~USB_PORT_STAT_CONNECTION;
+	status |= (1 << USB_PORT_FEAT_C_CONNECTION);
 
-	the_controller->port_status[rhport] &= ~USB_PORT_STAT_CONNECTION;
-	the_controller->port_status[rhport] |=
-					(1 << USB_PORT_FEAT_C_CONNECTION);
+	vhci->port_status[rhport] = status;
 
-	spin_unlock_irqrestore(&the_controller->lock, flags);
-	usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
+	spin_unlock_irqrestore(&vhci->lock, flags);
+	usb_hcd_poll_rh_status(vhci_to_hcd(vhci));
 }
 
 #define PORT_C_MASK				\
@@ -188,7 +203,7 @@ static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
 	int		changed = 0;
 	unsigned long	flags;
 
-	retval = DIV_ROUND_UP(VHCI_NPORTS + 1, 8);
+	retval = DIV_ROUND_UP(VHCI_HC_PORTS + 1, 8);
 	memset(buf, 0, retval);
 
 	vhci = hcd_to_vhci(hcd);
@@ -200,7 +215,7 @@ static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
 	}
 
 	/* check pseudo status register for each port */
-	for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
+	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 		if ((vhci->port_status[rhport] & PORT_C_MASK)) {
 			/* The status of a port has been changed, */
 			usbip_dbg_vhci_rh("port %d status changed\n", rhport);
@@ -225,7 +240,7 @@ static inline void hub_descriptor(struct usb_hub_descriptor *desc)
 	desc->bDescLength = 9;
 	desc->wHubCharacteristics = cpu_to_le16(
 		HUB_CHAR_INDV_PORT_LPSM | HUB_CHAR_COMMON_OCPM);
-	desc->bNbrPorts = VHCI_NPORTS;
+	desc->bNbrPorts = VHCI_HC_PORTS;
 	desc->u.hs.DeviceRemovable[0] = 0xff;
 	desc->u.hs.DeviceRemovable[1] = 0xff;
 }
@@ -238,7 +253,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 	int		rhport;
 	unsigned long	flags;
 
-	u32 prev_port_status[VHCI_NPORTS];
+	u32 prev_port_status[VHCI_HC_PORTS];
 
 	if (!HCD_HW_ACCESSIBLE(hcd))
 		return -ETIMEDOUT;
@@ -249,7 +264,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 	 */
 	usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue,
 			  wIndex);
-	if (wIndex > VHCI_NPORTS)
+	if (wIndex > VHCI_HC_PORTS)
 		pr_err("invalid port number %d\n", wIndex);
 	rhport = ((__u8)(wIndex & 0x00ff)) - 1;
 
@@ -315,7 +330,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 		break;
 	case GetPortStatus:
 		usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex);
-		if (wIndex > VHCI_NPORTS || wIndex < 1) {
+		if (wIndex > VHCI_HC_PORTS || wIndex < 1) {
 			pr_err("invalid port number %d\n", wIndex);
 			retval = -EPIPE;
 		}
@@ -416,14 +431,27 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
 static struct vhci_device *get_vdev(struct usb_device *udev)
 {
-	int i;
+	struct platform_device *pdev;
+	struct usb_hcd *hcd;
+	struct vhci_hcd *vhci;
+	int pdev_nr, rhport;
 
 	if (!udev)
 		return NULL;
 
-	for (i = 0; i < VHCI_NPORTS; i++)
-		if (the_controller->vdev[i].udev == udev)
-			return port_to_vdev(i);
+	for (pdev_nr = 0; pdev_nr < vhci_num_controllers; pdev_nr++) {
+		pdev = *(vhci_pdevs + pdev_nr);
+		if (pdev == NULL)
+			continue;
+		hcd = platform_get_drvdata(pdev);
+		if (hcd == NULL)
+			continue;
+		vhci = hcd_to_vhci(hcd);
+		for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
+			if (vhci->vdev[rhport].udev == udev)
+				return &vhci->vdev[rhport];
+		}
+	}
 
 	return NULL;
 }
@@ -432,6 +460,7 @@ static void vhci_tx_urb(struct urb *urb)
 {
 	struct vhci_device *vdev = get_vdev(urb->dev);
 	struct vhci_priv *priv;
+	struct vhci_hcd *vhci = vdev_to_vhci(vdev);
 	unsigned long flags;
 
 	if (!vdev) {
@@ -447,7 +476,7 @@ static void vhci_tx_urb(struct urb *urb)
 
 	spin_lock_irqsave(&vdev->priv_lock, flags);
 
-	priv->seqnum = atomic_inc_return(&the_controller->seqnum);
+	priv->seqnum = atomic_inc_return(&vhci->seqnum);
 	if (priv->seqnum == 0xffff)
 		dev_info(&urb->dev->dev, "seqnum max\n");
 
@@ -465,7 +494,9 @@ static void vhci_tx_urb(struct urb *urb)
 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 			    gfp_t mem_flags)
 {
+	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 	struct device *dev = &urb->dev->dev;
+	u8 portnum = urb->dev->portnum;
 	int ret = 0;
 	struct vhci_device *vdev;
 	unsigned long flags;
@@ -473,26 +504,30 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 	usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
 			  hcd, urb, mem_flags);
 
+	if (portnum > VHCI_HC_PORTS) {
+		pr_err("invalid port number %d\n", portnum);
+		return -ENODEV;
+	}
+	vdev = &vhci->vdev[portnum-1];
+
 	/* patch to usb_sg_init() is in 2.5.60 */
 	BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 
-	spin_lock_irqsave(&the_controller->lock, flags);
+	spin_lock_irqsave(&vhci->lock, flags);
 
 	if (urb->status != -EINPROGRESS) {
 		dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
-		spin_unlock_irqrestore(&the_controller->lock, flags);
+		spin_unlock_irqrestore(&vhci->lock, flags);
 		return urb->status;
 	}
 
-	vdev = port_to_vdev(urb->dev->portnum-1);
-
 	/* refuse enqueue for dead connection */
 	spin_lock(&vdev->ud.lock);
 	if (vdev->ud.status == VDEV_ST_NULL ||
 	    vdev->ud.status == VDEV_ST_ERROR) {
 		dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
 		spin_unlock(&vdev->ud.lock);
-		spin_unlock_irqrestore(&the_controller->lock, flags);
+		spin_unlock_irqrestore(&vhci->lock, flags);
 		return -ENODEV;
 	}
 	spin_unlock(&vdev->ud.lock);
@@ -565,17 +600,16 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 
 out:
 	vhci_tx_urb(urb);
-	spin_unlock_irqrestore(&the_controller->lock, flags);
+	spin_unlock_irqrestore(&vhci->lock, flags);
 
 	return 0;
 
 no_need_xmit:
 	usb_hcd_unlink_urb_from_ep(hcd, urb);
 no_need_unlink:
-	spin_unlock_irqrestore(&the_controller->lock, flags);
+	spin_unlock_irqrestore(&vhci->lock, flags);
 	if (!ret)
-		usb_hcd_giveback_urb(vhci_to_hcd(the_controller),
-				     urb, urb->status);
+		usb_hcd_giveback_urb(hcd, urb, urb->status);
 	return ret;
 }
 
@@ -627,19 +661,20 @@ no_need_unlink:
  */
 static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 {
+	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
 	struct vhci_priv *priv;
 	struct vhci_device *vdev;
 	unsigned long flags;
 
 	pr_info("dequeue a urb %p\n", urb);
 
-	spin_lock_irqsave(&the_controller->lock, flags);
+	spin_lock_irqsave(&vhci->lock, flags);
 
 	priv = urb->hcpriv;
 	if (!priv) {
 		/* URB was never linked! or will be soon given back by
 		 * vhci_rx. */
-		spin_unlock_irqrestore(&the_controller->lock, flags);
+		spin_unlock_irqrestore(&vhci->lock, flags);
 		return -EIDRM;
 	}
 
@@ -648,7 +683,7 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 
 		ret = usb_hcd_check_unlink_urb(hcd, urb, status);
 		if (ret) {
-			spin_unlock_irqrestore(&the_controller->lock, flags);
+			spin_unlock_irqrestore(&vhci->lock, flags);
 			return ret;
 		}
 	}
@@ -676,10 +711,9 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 
 		usb_hcd_unlink_urb_from_ep(hcd, urb);
 
-		spin_unlock_irqrestore(&the_controller->lock, flags);
-		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
-				     urb->status);
-		spin_lock_irqsave(&the_controller->lock, flags);
+		spin_unlock_irqrestore(&vhci->lock, flags);
+		usb_hcd_giveback_urb(vhci_to_hcd(vhci), urb, urb->status);
+		spin_lock_irqsave(&vhci->lock, flags);
 
 	} else {
 		/* tcp connection is alive */
@@ -691,12 +725,12 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 		unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
 		if (!unlink) {
 			spin_unlock(&vdev->priv_lock);
-			spin_unlock_irqrestore(&the_controller->lock, flags);
+			spin_unlock_irqrestore(&vhci->lock, flags);
 			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
 			return -ENOMEM;
 		}
 
-		unlink->seqnum = atomic_inc_return(&the_controller->seqnum);
+		unlink->seqnum = atomic_inc_return(&vhci->seqnum);
 		if (unlink->seqnum == 0xffff)
 			pr_info("seqnum max\n");
 
@@ -712,7 +746,7 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 		spin_unlock(&vdev->priv_lock);
 	}
 
-	spin_unlock_irqrestore(&the_controller->lock, flags);
+	spin_unlock_irqrestore(&vhci->lock, flags);
 
 	usbip_dbg_vhci_hc("leave\n");
 	return 0;
@@ -720,10 +754,12 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 
 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 {
+	struct vhci_hcd *vhci = vdev_to_vhci(vdev);
+	struct usb_hcd *hcd = vhci_to_hcd(vhci);
 	struct vhci_unlink *unlink, *tmp;
 	unsigned long flags;
 
-	spin_lock_irqsave(&the_controller->lock, flags);
+	spin_lock_irqsave(&vhci->lock, flags);
 	spin_lock(&vdev->priv_lock);
 
 	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
@@ -752,24 +788,23 @@ static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 
 		urb->status = -ENODEV;
 
-		usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
+		usb_hcd_unlink_urb_from_ep(hcd, urb);
 
 		list_del(&unlink->list);
 
 		spin_unlock(&vdev->priv_lock);
-		spin_unlock_irqrestore(&the_controller->lock, flags);
+		spin_unlock_irqrestore(&vhci->lock, flags);
 
-		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
-				     urb->status);
+		usb_hcd_giveback_urb(hcd, urb, urb->status);
 
-		spin_lock_irqsave(&the_controller->lock, flags);
+		spin_lock_irqsave(&vhci->lock, flags);
 		spin_lock(&vdev->priv_lock);
 
 		kfree(unlink);
 	}
 
 	spin_unlock(&vdev->priv_lock);
-	spin_unlock_irqrestore(&the_controller->lock, flags);
+	spin_unlock_irqrestore(&vhci->lock, flags);
 }
 
 /*
@@ -827,7 +862,7 @@ static void vhci_shutdown_connection(struct usbip_device *ud)
 	 * is actually given back by vhci_rx after receiving its return pdu.
 	 *
 	 */
-	rh_port_disconnect(vdev->rhport);
+	rh_port_disconnect(vdev);
 
 	pr_info("disconnect device\n");
 }
@@ -866,7 +901,7 @@ static void vhci_device_unusable(struct usbip_device *ud)
 
 static void vhci_device_init(struct vhci_device *vdev)
 {
-	memset(vdev, 0, sizeof(*vdev));
+	memset(vdev, 0, sizeof(struct vhci_device));
 
 	vdev->ud.side   = USBIP_VHCI;
 	vdev->ud.status = VDEV_ST_NULL;
@@ -887,17 +922,34 @@ static void vhci_device_init(struct vhci_device *vdev)
 	usbip_start_eh(&vdev->ud);
 }
 
+static int hcd_name_to_id(const char *name)
+{
+	char *c;
+	long val;
+	int ret;
+
+	c = strchr(name, '.');
+	if (c == NULL)
+		return 0;
+
+	ret = kstrtol(c+1, 10, &val);
+	if (ret < 0)
+		return ret;
+
+	return val;
+}
+
 static int vhci_start(struct usb_hcd *hcd)
 {
 	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
-	int rhport;
+	int id, rhport;
 	int err = 0;
 
 	usbip_dbg_vhci_hc("enter vhci_start\n");
 
 	/* initialize private data of usb_hcd */
 
-	for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
+	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 		struct vhci_device *vdev = &vhci->vdev[rhport];
 
 		vhci_device_init(vdev);
@@ -910,11 +962,26 @@ static int vhci_start(struct usb_hcd *hcd)
 	hcd->power_budget = 0; /* no limit */
 	hcd->uses_new_polling = 1;
 
+	id = hcd_name_to_id(hcd_name(hcd));
+	if (id < 0) {
+		pr_err("invalid vhci name %s\n", hcd_name(hcd));
+		return -EINVAL;
+	}
+
 	/* vhci_hcd is now ready to be controlled through sysfs */
-	err = sysfs_create_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
-	if (err) {
-		pr_err("create sysfs files\n");
-		return err;
+	if (id == 0) {
+		err = vhci_init_attr_group();
+		if (err) {
+			pr_err("init attr group\n");
+			return err;
+		}
+		err = sysfs_create_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
+		if (err) {
+			pr_err("create sysfs files\n");
+			vhci_finish_attr_group();
+			return err;
+		}
+		pr_info("created sysfs %s\n", hcd_name(hcd));
 	}
 
 	return 0;
@@ -923,15 +990,19 @@ static int vhci_start(struct usb_hcd *hcd)
 static void vhci_stop(struct usb_hcd *hcd)
 {
 	struct vhci_hcd *vhci = hcd_to_vhci(hcd);
-	int rhport = 0;
+	int id, rhport;
 
 	usbip_dbg_vhci_hc("stop VHCI controller\n");
 
 	/* 1. remove the userland interface of vhci_hcd */
-	sysfs_remove_group(&vhci_dev(vhci)->kobj, &dev_attr_group);
+	id = hcd_name_to_id(hcd_name(hcd));
+	if (id == 0) {
+		sysfs_remove_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
+		vhci_finish_attr_group();
+	}
 
 	/* 2. shutdown all the ports of vhci_hcd */
-	for (rhport = 0; rhport < VHCI_NPORTS; rhport++) {
+	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 		struct vhci_device *vdev = &vhci->vdev[rhport];
 
 		usbip_event_add(&vdev->ud, VDEV_EVENT_REMOVED);
@@ -1025,9 +1096,6 @@ static int vhci_hcd_probe(struct platform_device *pdev)
 	}
 	hcd->has_tt = 1;
 
-	/* this is private data for vhci_hcd */
-	the_controller = hcd_to_vhci(hcd);
-
 	/*
 	 * Finish generic HCD structure initialization and register.
 	 * Call the driver's reset() and start() routines.
@@ -1036,7 +1104,6 @@ static int vhci_hcd_probe(struct platform_device *pdev)
 	if (ret != 0) {
 		pr_err("usb_add_hcd failed %d\n", ret);
 		usb_put_hcd(hcd);
-		the_controller = NULL;
 		return ret;
 	}
 
@@ -1059,7 +1126,6 @@ static int vhci_hcd_remove(struct platform_device *pdev)
 	 */
 	usb_remove_hcd(hcd);
 	usb_put_hcd(hcd);
-	the_controller = NULL;
 
 	return 0;
 }
@@ -1070,21 +1136,24 @@ static int vhci_hcd_remove(struct platform_device *pdev)
 static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
 {
 	struct usb_hcd *hcd;
-	int rhport = 0;
+	struct vhci_hcd *vhci;
+	int rhport;
 	int connected = 0;
 	int ret = 0;
 	unsigned long flags;
 
 	hcd = platform_get_drvdata(pdev);
+	if (!hcd)
+		return 0;
+	vhci = hcd_to_vhci(hcd);
 
-	spin_lock_irqsave(&the_controller->lock, flags);
+	spin_lock_irqsave(&vhci->lock, flags);
 
-	for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
-		if (the_controller->port_status[rhport] &
-		    USB_PORT_STAT_CONNECTION)
+	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++)
+		if (vhci->port_status[rhport] & USB_PORT_STAT_CONNECTION)
 			connected += 1;
 
-	spin_unlock_irqrestore(&the_controller->lock, flags);
+	spin_unlock_irqrestore(&vhci->lock, flags);
 
 	if (connected > 0) {
 		dev_info(&pdev->dev,
@@ -1106,6 +1175,8 @@ static int vhci_hcd_resume(struct platform_device *pdev)
 	dev_dbg(&pdev->dev, "%s\n", __func__);
 
 	hcd = platform_get_drvdata(pdev);
+	if (!hcd)
+		return 0;
 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 	usb_hcd_poll_rh_status(hcd);
 
@@ -1129,52 +1200,78 @@ static struct platform_driver vhci_driver = {
 	},
 };
 
-/*
- * The VHCI 'device' is 'virtual'; not a real plug&play hardware.
- * We need to add this virtual device as a platform device arbitrarily:
- *	1. platform_device_register()
- */
-static void the_pdev_release(struct device *dev)
+static int add_platform_device(int id)
 {
+	struct platform_device *pdev;
+	int dev_nr;
+
+	if (id == 0)
+		dev_nr = -1;
+	else
+		dev_nr = id;
+
+	pdev = platform_device_register_simple(driver_name, dev_nr, NULL, 0);
+	if (pdev == NULL)
+		return -ENODEV;
+
+	*(vhci_pdevs + id) = pdev;
+	return 0;
 }
 
-static struct platform_device the_pdev = {
-	/* should be the same name as driver_name */
-	.name = driver_name,
-	.id = -1,
-	.dev = {
-		.release = the_pdev_release,
-	},
-};
+static void del_platform_devices(void)
+{
+	struct platform_device *pdev;
+	int i;
+
+	for (i = 0; i < vhci_num_controllers; i++) {
+		pdev = *(vhci_pdevs + i);
+		if (pdev != NULL)
+			platform_device_unregister(pdev);
+		*(vhci_pdevs + i) = NULL;
+	}
+	sysfs_remove_link(&platform_bus.kobj, driver_name);
+}
 
 static int __init vhci_hcd_init(void)
 {
-	int ret;
+	int i, ret;
 
 	if (usb_disabled())
 		return -ENODEV;
 
+	if (vhci_num_controllers < 1)
+		vhci_num_controllers = 1;
+
+	vhci_pdevs = kcalloc(vhci_num_controllers, sizeof(void *), GFP_KERNEL);
+	if (vhci_pdevs == NULL)
+		return -ENOMEM;
+
 	ret = platform_driver_register(&vhci_driver);
 	if (ret)
 		goto err_driver_register;
 
-	ret = platform_device_register(&the_pdev);
-	if (ret)
-		goto err_platform_device_register;
+	for (i = 0; i < vhci_num_controllers; i++) {
+		ret = add_platform_device(i);
+		if (ret)
+			goto err_platform_device_register;
+	}
 
 	pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
 	return ret;
 
 err_platform_device_register:
+	del_platform_devices();
 	platform_driver_unregister(&vhci_driver);
 err_driver_register:
+	kfree(vhci_pdevs);
 	return ret;
 }
 
 static void __exit vhci_hcd_exit(void)
 {
-	platform_device_unregister(&the_pdev);
+	del_platform_devices();
 	platform_driver_unregister(&vhci_driver);
+	kfree(vhci_pdevs);
 }
 
 module_init(vhci_hcd_init);