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	Add the definition of pvUSB protocol used between the pvUSB frontend in a Xen domU and the pvUSB backend in a Xen driver domain (usually Dom0). This header was originally provided by Fujitsu for Xen based on Linux 2.6.18. Changes are: - adapt to Linux kernel style guide - use Xen namespace - add lots of comments - don't use kernel internal defines Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20211123132048.5335-2-jgross@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
		
			
				
	
	
		
			405 lines
		
	
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			405 lines
		
	
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: MIT */
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/*
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 * usbif.h
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 *
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 * USB I/O interface for Xen guest OSes.
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 *
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 * Copyright (C) 2009, FUJITSU LABORATORIES LTD.
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 * Author: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
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 */
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#ifndef __XEN_PUBLIC_IO_USBIF_H__
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#define __XEN_PUBLIC_IO_USBIF_H__
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#include "ring.h"
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#include "../grant_table.h"
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/*
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 * Detailed Interface Description
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 * ==============================
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 * The pvUSB interface is using a split driver design: a frontend driver in
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 * the guest and a backend driver in a driver domain (normally dom0) having
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 * access to the physical USB device(s) being passed to the guest.
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 *
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 * The frontend and backend drivers use XenStore to initiate the connection
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 * between them, the I/O activity is handled via two shared ring pages and an
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 * event channel. As the interface between frontend and backend is at the USB
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 * host connector level, multiple (up to 31) physical USB devices can be
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 * handled by a single connection.
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 *
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 * The Xen pvUSB device name is "qusb", so the frontend's XenStore entries are
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 * to be found under "device/qusb", while the backend's XenStore entries are
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 * under "backend/<guest-dom-id>/qusb".
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 *
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 * When a new pvUSB connection is established, the frontend needs to setup the
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 * two shared ring pages for communication and the event channel. The ring
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 * pages need to be made available to the backend via the grant table
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 * interface.
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 *
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 * One of the shared ring pages is used by the backend to inform the frontend
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 * about USB device plug events (device to be added or removed). This is the
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 * "conn-ring".
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 *
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 * The other ring page is used for USB I/O communication (requests and
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 * responses). This is the "urb-ring".
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 *
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 * Feature and Parameter Negotiation
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 * =================================
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 * The two halves of a Xen pvUSB driver utilize nodes within the XenStore to
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 * communicate capabilities and to negotiate operating parameters. This
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 * section enumerates these nodes which reside in the respective front and
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 * backend portions of the XenStore, following the XenBus convention.
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 *
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 * Any specified default value is in effect if the corresponding XenBus node
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 * is not present in the XenStore.
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 *
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 * XenStore nodes in sections marked "PRIVATE" are solely for use by the
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 * driver side whose XenBus tree contains them.
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 *
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 *****************************************************************************
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 *                            Backend XenBus Nodes
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 *****************************************************************************
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 *
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 *------------------ Backend Device Identification (PRIVATE) ------------------
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 *
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 * num-ports
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 *      Values:         unsigned [1...31]
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 *
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 *      Number of ports for this (virtual) USB host connector.
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 *
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 * usb-ver
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 *      Values:         unsigned [1...2]
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 *
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 *      USB version of this host connector: 1 = USB 1.1, 2 = USB 2.0.
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 *
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 * port/[1...31]
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 *      Values:         string
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 *
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 *      Physical USB device connected to the given port, e.g. "3-1.5".
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 *
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 *****************************************************************************
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 *                            Frontend XenBus Nodes
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 *****************************************************************************
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 *
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 *----------------------- Request Transport Parameters -----------------------
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 *
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 * event-channel
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 *      Values:         unsigned
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 *
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 *      The identifier of the Xen event channel used to signal activity
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 *      in the ring buffer.
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 *
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 * urb-ring-ref
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 *      Values:         unsigned
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 *
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 *      The Xen grant reference granting permission for the backend to map
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 *      the sole page in a single page sized ring buffer. This is the ring
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 *      buffer for urb requests.
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 *
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 * conn-ring-ref
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 *      Values:         unsigned
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 *
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 *      The Xen grant reference granting permission for the backend to map
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 *      the sole page in a single page sized ring buffer. This is the ring
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 *      buffer for connection/disconnection requests.
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 *
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 * protocol
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 *      Values:         string (XEN_IO_PROTO_ABI_*)
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 *      Default Value:  XEN_IO_PROTO_ABI_NATIVE
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 *
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 *      The machine ABI rules governing the format of all ring request and
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 *      response structures.
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 *
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 * Protocol Description
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 * ====================
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 *
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 *-------------------------- USB device plug events --------------------------
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 *
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 * USB device plug events are send via the "conn-ring" shared page. As only
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 * events are being sent, the respective requests from the frontend to the
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 * backend are just dummy ones.
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 * The events sent to the frontend have the following layout:
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 *         0                1                 2               3        octet
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 * +----------------+----------------+----------------+----------------+
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 * |               id                |    portnum     |     speed      | 4
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 * +----------------+----------------+----------------+----------------+
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 *   id - uint16_t, event id (taken from the actual frontend dummy request)
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 *   portnum - uint8_t, port number (1 ... 31)
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 *   speed - uint8_t, device XENUSB_SPEED_*, XENUSB_SPEED_NONE == unplug
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 *
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 * The dummy request:
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 *         0                1        octet
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 * +----------------+----------------+
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 * |               id                | 2
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 * +----------------+----------------+
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 *   id - uint16_t, guest supplied value (no need for being unique)
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 *
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 *-------------------------- USB I/O request ---------------------------------
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 *
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 * A single USB I/O request on the "urb-ring" has the following layout:
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 *         0                1                 2               3        octet
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 * +----------------+----------------+----------------+----------------+
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 * |               id                |         nr_buffer_segs          | 4
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 * +----------------+----------------+----------------+----------------+
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 * |                               pipe                                | 8
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 * +----------------+----------------+----------------+----------------+
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 * |         transfer_flags          |          buffer_length          | 12
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 * +----------------+----------------+----------------+----------------+
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 * |                       request type specific                       | 16
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 * |                               data                                | 20
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 * +----------------+----------------+----------------+----------------+
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 * |                              seg[0]                               | 24
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 * |                               data                                | 28
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 * +----------------+----------------+----------------+----------------+
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 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
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 * +----------------+----------------+----------------+----------------+
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 * |             seg[XENUSB_MAX_SEGMENTS_PER_REQUEST - 1]              | 144
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 * |                               data                                | 148
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 * +----------------+----------------+----------------+----------------+
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 * Bit field bit number 0 is always least significant bit, undefined bits must
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 * be zero.
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 *   id - uint16_t, guest supplied value
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 *   nr_buffer_segs - uint16_t, number of segment entries in seg[] array
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 *   pipe - uint32_t, bit field with multiple information:
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 *     bits 0-4: port request to send to
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 *     bit 5: unlink request with specified id (cancel I/O) if set (see below)
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 *     bit 7: direction (1 = read from device)
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 *     bits 8-14: device number on port
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 *     bits 15-18: endpoint of device
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 *     bits 30-31: request type: 00 = isochronous, 01 = interrupt,
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 *                               10 = control, 11 = bulk
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 *   transfer_flags - uint16_t, bit field with processing flags:
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 *     bit 0: less data than specified allowed
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 *   buffer_length - uint16_t, total length of data
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 *   request type specific data - 8 bytes, see below
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 *   seg[] - array with 8 byte elements, see below
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 *
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 * Request type specific data for isochronous request:
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 *         0                1                 2               3        octet
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 * +----------------+----------------+----------------+----------------+
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 * |            interval             |           start_frame           | 4
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 * +----------------+----------------+----------------+----------------+
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 * |       number_of_packets         |       nr_frame_desc_segs        | 8
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 * +----------------+----------------+----------------+----------------+
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 *   interval - uint16_t, time interval in msecs between frames
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 *   start_frame - uint16_t, start frame number
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 *   number_of_packets - uint16_t, number of packets to transfer
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 *   nr_frame_desc_segs - uint16_t number of seg[] frame descriptors elements
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 *
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 * Request type specific data for interrupt request:
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 *         0                1                 2               3        octet
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 * +----------------+----------------+----------------+----------------+
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 * |            interval             |                0                | 4
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 * +----------------+----------------+----------------+----------------+
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 * |                                 0                                 | 8
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 * +----------------+----------------+----------------+----------------+
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 *   interval - uint16_t, time in msecs until interruption
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 *
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 * Request type specific data for control request:
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 *         0                1                 2               3        octet
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 * +----------------+----------------+----------------+----------------+
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 * |                      data of setup packet                         | 4
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 * |                                                                   | 8
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 * +----------------+----------------+----------------+----------------+
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 *
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 * Request type specific data for bulk request:
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 *         0                1                 2               3        octet
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 * +----------------+----------------+----------------+----------------+
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 * |                                 0                                 | 4
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 * |                                 0                                 | 8
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 * +----------------+----------------+----------------+----------------+
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 *
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 * Request type specific data for unlink request:
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 *         0                1                 2               3        octet
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 * +----------------+----------------+----------------+----------------+
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 * |           unlink_id             |                0                | 4
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 * +----------------+----------------+----------------+----------------+
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 * |                                 0                                 | 8
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 * +----------------+----------------+----------------+----------------+
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 *   unlink_id - uint16_t, request id of request to terminate
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 *
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 * seg[] array element layout:
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 *         0                1                 2               3        octet
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 * +----------------+----------------+----------------+----------------+
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 * |                               gref                                | 4
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 * +----------------+----------------+----------------+----------------+
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 * |             offset              |             length              | 8
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 * +----------------+----------------+----------------+----------------+
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 *   gref - uint32_t, grant reference of buffer page
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 *   offset - uint16_t, offset of buffer start in page
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 *   length - uint16_t, length of buffer in page
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 *
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 *-------------------------- USB I/O response --------------------------------
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 *
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 *         0                1                 2               3        octet
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 * +----------------+----------------+----------------+----------------+
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 * |               id                |          start_frame            | 4
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 * +----------------+----------------+----------------+----------------+
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 * |                              status                               | 8
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 * +----------------+----------------+----------------+----------------+
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 * |                          actual_length                            | 12
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 * +----------------+----------------+----------------+----------------+
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 * |                           error_count                             | 16
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 * +----------------+----------------+----------------+----------------+
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 *   id - uint16_t, id of the request this response belongs to
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 *   start_frame - uint16_t, start_frame this response (iso requests only)
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 *   status - int32_t, XENUSB_STATUS_* (non-iso requests)
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 *   actual_length - uint32_t, actual size of data transferred
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 *   error_count - uint32_t, number of errors (iso requests)
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 */
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enum xenusb_spec_version {
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	XENUSB_VER_UNKNOWN = 0,
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	XENUSB_VER_USB11,
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	XENUSB_VER_USB20,
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	XENUSB_VER_USB30,	/* not supported yet */
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};
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/*
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 *  USB pipe in xenusb_request
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 *
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 *  - port number:      bits 0-4
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 *                              (USB_MAXCHILDREN is 31)
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 *
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 *  - operation flag:   bit 5
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 *                              (0 = submit urb,
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 *                               1 = unlink urb)
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 *
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 *  - direction:        bit 7
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 *                              (0 = Host-to-Device [Out]
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 *                               1 = Device-to-Host [In])
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 *
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 *  - device address:   bits 8-14
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 *
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 *  - endpoint:         bits 15-18
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 *
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 *  - pipe type:        bits 30-31
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 *                              (00 = isochronous, 01 = interrupt,
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 *                               10 = control, 11 = bulk)
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 */
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#define XENUSB_PIPE_PORT_MASK	0x0000001f
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#define XENUSB_PIPE_UNLINK	0x00000020
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#define XENUSB_PIPE_DIR		0x00000080
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#define XENUSB_PIPE_DEV_MASK	0x0000007f
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#define XENUSB_PIPE_DEV_SHIFT	8
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#define XENUSB_PIPE_EP_MASK	0x0000000f
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#define XENUSB_PIPE_EP_SHIFT	15
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#define XENUSB_PIPE_TYPE_MASK	0x00000003
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#define XENUSB_PIPE_TYPE_SHIFT	30
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#define XENUSB_PIPE_TYPE_ISOC	0
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#define XENUSB_PIPE_TYPE_INT	1
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#define XENUSB_PIPE_TYPE_CTRL	2
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#define XENUSB_PIPE_TYPE_BULK	3
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#define xenusb_pipeportnum(pipe)		((pipe) & XENUSB_PIPE_PORT_MASK)
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#define xenusb_setportnum_pipe(pipe, portnum)	((pipe) | (portnum))
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#define xenusb_pipeunlink(pipe)			((pipe) & XENUSB_PIPE_UNLINK)
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#define xenusb_pipesubmit(pipe)			(!xenusb_pipeunlink(pipe))
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#define xenusb_setunlink_pipe(pipe)		((pipe) | XENUSB_PIPE_UNLINK)
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#define xenusb_pipein(pipe)			((pipe) & XENUSB_PIPE_DIR)
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#define xenusb_pipeout(pipe)			(!xenusb_pipein(pipe))
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#define xenusb_pipedevice(pipe)			\
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	(((pipe) >> XENUSB_PIPE_DEV_SHIFT) & XENUSB_PIPE_DEV_MASK)
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#define xenusb_pipeendpoint(pipe)		\
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	(((pipe) >> XENUSB_PIPE_EP_SHIFT) & XENUSB_PIPE_EP_MASK)
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#define xenusb_pipetype(pipe)			\
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	(((pipe) >> XENUSB_PIPE_TYPE_SHIFT) & XENUSB_PIPE_TYPE_MASK)
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#define xenusb_pipeisoc(pipe)	(xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_ISOC)
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#define xenusb_pipeint(pipe)	(xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_INT)
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#define xenusb_pipectrl(pipe)	(xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_CTRL)
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#define xenusb_pipebulk(pipe)	(xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_BULK)
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#define XENUSB_MAX_SEGMENTS_PER_REQUEST (16)
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#define XENUSB_MAX_PORTNR		31
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#define XENUSB_RING_SIZE		4096
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/*
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 * RING for transferring urbs.
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 */
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struct xenusb_request_segment {
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	grant_ref_t gref;
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	uint16_t offset;
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	uint16_t length;
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};
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struct xenusb_urb_request {
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	uint16_t id;			/* request id */
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	uint16_t nr_buffer_segs;	/* number of urb->transfer_buffer segments */
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	/* basic urb parameter */
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	uint32_t pipe;
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	uint16_t transfer_flags;
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#define XENUSB_SHORT_NOT_OK	0x0001
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	uint16_t buffer_length;
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	union {
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		uint8_t ctrl[8];	/* setup_packet (Ctrl) */
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		struct {
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			uint16_t interval;	/* maximum (1024*8) in usb core */
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			uint16_t start_frame;	/* start frame */
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			uint16_t number_of_packets;	/* number of ISO packet */
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			uint16_t nr_frame_desc_segs;	/* number of iso_frame_desc segments */
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		} isoc;
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		struct {
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			uint16_t interval;	/* maximum (1024*8) in usb core */
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			uint16_t pad[3];
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		} intr;
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		struct {
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			uint16_t unlink_id;	/* unlink request id */
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			uint16_t pad[3];
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		} unlink;
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	} u;
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	/* urb data segments */
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	struct xenusb_request_segment seg[XENUSB_MAX_SEGMENTS_PER_REQUEST];
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};
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struct xenusb_urb_response {
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	uint16_t id;		/* request id */
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	uint16_t start_frame;	/* start frame (ISO) */
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	int32_t status;		/* status (non-ISO) */
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#define XENUSB_STATUS_OK	0
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#define XENUSB_STATUS_NODEV	(-19)
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#define XENUSB_STATUS_INVAL	(-22)
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#define XENUSB_STATUS_STALL	(-32)
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#define XENUSB_STATUS_IOERROR	(-71)
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#define XENUSB_STATUS_BABBLE	(-75)
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#define XENUSB_STATUS_SHUTDOWN	(-108)
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	int32_t actual_length;	/* actual transfer length */
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	int32_t error_count;	/* number of ISO errors */
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};
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DEFINE_RING_TYPES(xenusb_urb, struct xenusb_urb_request, struct xenusb_urb_response);
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#define XENUSB_URB_RING_SIZE __CONST_RING_SIZE(xenusb_urb, XENUSB_RING_SIZE)
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/*
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 * RING for notifying connect/disconnect events to frontend
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 */
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struct xenusb_conn_request {
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	uint16_t id;
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};
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struct xenusb_conn_response {
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	uint16_t id;		/* request id */
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						|
	uint8_t portnum;	/* port number */
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						|
	uint8_t speed;		/* usb_device_speed */
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						|
#define XENUSB_SPEED_NONE	0
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						|
#define XENUSB_SPEED_LOW	1
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						|
#define XENUSB_SPEED_FULL	2
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						|
#define XENUSB_SPEED_HIGH	3
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						|
};
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						|
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						|
DEFINE_RING_TYPES(xenusb_conn, struct xenusb_conn_request, struct xenusb_conn_response);
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						|
#define XENUSB_CONN_RING_SIZE __CONST_RING_SIZE(xenusb_conn, XENUSB_RING_SIZE)
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						|
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						|
#endif /* __XEN_PUBLIC_IO_USBIF_H__ */
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