Staging: USB/IP: add client driver

	  module will be called usbip_common_mod.

	  If unsure, say N.

config USB_IP_VHCI_HCD

	tristate "USB IP client driver"

	depends on USB_IP_COMMON

	default N

	---help---

	 This enables the USB IP host controller driver which will

	 run on the client machine.

	 To compile this driver as a module, choose M here: the

	 module will be called vhci_hcd.

obj-$(CONFIG_USB_IP_COMMON) += usbip_common_mod.o

usbip_common_mod-objs := usbip_common.o usbip_event.o

obj-$(CONFIG_USB_IP_VHCI_HCD) += vhci-hcd.o

vhci-hcd-objs := vhci_sysfs.o vhci_tx.o vhci_rx.o vhci_hcd.o

ifeq ($(CONFIG_USB_DEBUG),y)

	EXTRA_CFLAGS += -DDEBUG

endif

/*

 * Copyright (C) 2003-2008 Takahiro Hirofuchi

 *

 * This is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,

 * USA.

 */

#include <linux/platform_device.h>

#include "../../usb/core/hcd.h"

struct vhci_device {

	struct usb_device *udev;

	/*

	 * devid specifies a remote usb device uniquely instead

	 * of combination of busnum and devnum.

	 */

	__u32 devid;

	/* speed of a remote device */

	enum usb_device_speed speed;

	/*  vhci root-hub port to which this device is attached  */

	__u32 rhport;

	struct usbip_device ud;

	/* lock for the below link lists */

	spinlock_t priv_lock;

	/* vhci_priv is linked to one of them. */

	struct list_head priv_tx;

	struct list_head priv_rx;

	/* vhci_unlink is linked to one of them */

	struct list_head unlink_tx;

	struct list_head unlink_rx;

	/* vhci_tx thread sleeps for this queue */

	wait_queue_head_t waitq_tx;

};

/* urb->hcpriv, use container_of() */

struct vhci_priv {

	unsigned long seqnum;

	struct list_head list;

	struct vhci_device *vdev;

	struct urb *urb;

};

struct vhci_unlink {

	/* seqnum of this request */

	unsigned long seqnum;

	struct list_head list;

	/* seqnum of the unlink target */

	unsigned long unlink_seqnum;

};

/*

 * The number of ports is less than 16 ?

 * USB_MAXCHILDREN is statically defined to 16 in usb.h.  Its maximum value

 * would be 31 because the event_bits[1] of struct usb_hub is defined as

 * unsigned long in hub.h

 */

#define VHCI_NPORTS 8

/* for usb_bus.hcpriv */

struct vhci_hcd {

	spinlock_t	lock;

	u32	port_status[VHCI_NPORTS];

	unsigned	resuming:1;

	unsigned long	re_timeout;

	atomic_t seqnum;

	/*

	 * NOTE:

	 * wIndex shows the port number and begins from 1.

	 * But, the index of this array begins from 0.

	 */

	struct vhci_device vdev[VHCI_NPORTS];

	/* vhci_device which has not been assiged its address yet */

	int pending_port;

};

extern struct vhci_hcd *the_controller;

extern struct attribute_group dev_attr_group;

/*-------------------------------------------------------------------------*/

/* prototype declaration */

/* vhci_hcd.c */

void rh_port_connect(int rhport, enum usb_device_speed speed);

void rh_port_disconnect(int rhport);

void vhci_rx_loop(struct usbip_task *ut);

void vhci_tx_loop(struct usbip_task *ut);

#define hardware		(&the_controller->pdev.dev)

static inline struct vhci_device *port_to_vdev(__u32 port)

{

	return &the_controller->vdev[port];

}

static inline struct vhci_hcd *hcd_to_vhci(struct usb_hcd *hcd)

{

	return (struct vhci_hcd *) (hcd->hcd_priv);

}

static inline struct usb_hcd *vhci_to_hcd(struct vhci_hcd *vhci)

{

	return container_of((void *) vhci, struct usb_hcd, hcd_priv);

}

static inline struct device *vhci_dev(struct vhci_hcd *vhci)

{

	return vhci_to_hcd(vhci)->self.controller;

}

/*

 * Copyright (C) 2003-2008 Takahiro Hirofuchi

 *

 * This is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,

 * USA.

 */

#include "usbip_common.h"

#include "vhci.h"

/* get URB from transmitted urb queue */

static struct urb *pickup_urb_and_free_priv(struct vhci_device *vdev,

					    __u32 seqnum)

{

	struct vhci_priv *priv, *tmp;

	struct urb *urb = NULL;

	int status;

	spin_lock(&vdev->priv_lock);

	list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {

		if (priv->seqnum == seqnum) {

			urb = priv->urb;

			status = urb->status;

			dbg_vhci_rx("find urb %p vurb %p seqnum %u\n",

				    urb, priv, seqnum);

			/* TODO: fix logic here to improve indent situtation */

			if (status != -EINPROGRESS) {

				if (status == -ENOENT ||

				     status == -ECONNRESET)

					dev_info(&urb->dev->dev,

						 "urb %p was unlinked "

						 "%ssynchronuously.\n", urb,

						 status == -ENOENT ? "" : "a");

				else

					dev_info(&urb->dev->dev,

						 "urb %p may be in a error, "

						 "status %d\n", urb, status);

			}

			list_del(&priv->list);

			kfree(priv);

			urb->hcpriv = NULL;

			break;

		}

	}

	spin_unlock(&vdev->priv_lock);

	return urb;

}

static void vhci_recv_ret_submit(struct vhci_device *vdev,

						struct usbip_header *pdu)

{

	struct usbip_device *ud = &vdev->ud;

	struct urb *urb;

	urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);

	if (!urb) {

		uerr("cannot find a urb of seqnum %u\n", pdu->base.seqnum);

		uinfo("max seqnum %d\n", atomic_read(&the_controller->seqnum));

		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);

		return;

	}

	/* unpack the pdu to a urb */

	usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);

	/* recv transfer buffer */

	if (usbip_recv_xbuff(ud, urb) < 0)

		return;

	/* recv iso_packet_descriptor */

	if (usbip_recv_iso(ud, urb) < 0)

		return;

	if (dbg_flag_vhci_rx)

		usbip_dump_urb(urb);

	dbg_vhci_rx("now giveback urb %p\n", urb);

	spin_lock(&the_controller->lock);

	usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);

	spin_unlock(&the_controller->lock);

	usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);

	dbg_vhci_rx("Leave\n");

	return;

}

static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,

		struct usbip_header *pdu)

{

	struct vhci_unlink *unlink, *tmp;

	spin_lock(&vdev->priv_lock);

	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {

		uinfo("unlink->seqnum %lu\n", unlink->seqnum);

		if (unlink->seqnum == pdu->base.seqnum) {

			dbg_vhci_rx("found pending unlink, %lu\n",

							unlink->seqnum);

			list_del(&unlink->list);

			spin_unlock(&vdev->priv_lock);

			return unlink;

		}

	}

	spin_unlock(&vdev->priv_lock);

	return NULL;

}

static void vhci_recv_ret_unlink(struct vhci_device *vdev,

						struct usbip_header *pdu)

{

	struct vhci_unlink *unlink;

	struct urb *urb;

	usbip_dump_header(pdu);

	unlink = dequeue_pending_unlink(vdev, pdu);

	if (!unlink) {

		uinfo("cannot find the pending unlink %u\n", pdu->base.seqnum);

		return;

	}

	urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);

	if (!urb) {

		/*

		 * I get the result of a unlink request. But, it seems that I

		 * already received the result of its submit result and gave

		 * back the URB.

		 */

		uinfo("the urb (seqnum %d) was already given backed\n",

							pdu->base.seqnum);

	} else {

		dbg_vhci_rx("now giveback urb %p\n", urb);

		/* If unlink is succeed, status is -ECONNRESET */

		urb->status = pdu->u.ret_unlink.status;

		uinfo("%d\n", urb->status);

		spin_lock(&the_controller->lock);

		usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);

		spin_unlock(&the_controller->lock);

		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,

								urb->status);

	}

	kfree(unlink);

	return;

}

/* recv a pdu */

static void vhci_rx_pdu(struct usbip_device *ud)

{

	int ret;

	struct usbip_header pdu;

	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);

	dbg_vhci_rx("Enter\n");

	memset(&pdu, 0, sizeof(pdu));

	/* 1. receive a pdu header */

	ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);

	if (ret != sizeof(pdu)) {

		uerr("receiving pdu failed! size is %d, should be %d\n",

				ret, sizeof(pdu));

		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);

		return;

	}

	usbip_header_correct_endian(&pdu, 0);

	if (dbg_flag_vhci_rx)

		usbip_dump_header(&pdu);

	switch (pdu.base.command) {

	case USBIP_RET_SUBMIT:

		vhci_recv_ret_submit(vdev, &pdu);

		break;

	case USBIP_RET_UNLINK:

		vhci_recv_ret_unlink(vdev, &pdu);

		break;

	default:

		/* NOTREACHED */

		uerr("unknown pdu %u\n", pdu.base.command);

		usbip_dump_header(&pdu);

		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);

	}

}

/*-------------------------------------------------------------------------*/

void vhci_rx_loop(struct usbip_task *ut)

{

	struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);

	while (1) {

		if (signal_pending(current)) {

			dbg_vhci_rx("signal catched!\n");

			break;

		}

		if (usbip_event_happend(ud))

			break;

		vhci_rx_pdu(ud);

	}

}