/* SPDX-License-Identifier: MIT */
/*
* usbif.h
*
* USB I/O interface for Xen guest OSes.
*
* Copyright (C) 2009, FUJITSU LABORATORIES LTD.
* Author: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
*/
#ifndef __XEN_PUBLIC_IO_USBIF_H__
#define __XEN_PUBLIC_IO_USBIF_H__
#include "ring.h"
#include "../grant_table.h"
/*
* Detailed Interface Description
* ==============================
* The pvUSB interface is using a split driver design: a frontend driver in
* the guest and a backend driver in a driver domain (normally dom0) having
* access to the physical USB device(s) being passed to the guest.
*
* The frontend and backend drivers use XenStore to initiate the connection
* between them, the I/O activity is handled via two shared ring pages and an
* event channel. As the interface between frontend and backend is at the USB
* host connector level, multiple (up to 31) physical USB devices can be
* handled by a single connection.
*
* The Xen pvUSB device name is "qusb", so the frontend's XenStore entries are
* to be found under "device/qusb", while the backend's XenStore entries are
* under "backend/<guest-dom-id>/qusb".
*
* When a new pvUSB connection is established, the frontend needs to setup the
* two shared ring pages for communication and the event channel. The ring
* pages need to be made available to the backend via the grant table
* interface.
*
* One of the shared ring pages is used by the backend to inform the frontend
* about USB device plug events (device to be added or removed). This is the
* "conn-ring".
*
* The other ring page is used for USB I/O communication (requests and
* responses). This is the "urb-ring".
*
* Feature and Parameter Negotiation
* =================================
* The two halves of a Xen pvUSB driver utilize nodes within the XenStore to
* communicate capabilities and to negotiate operating parameters. This
* section enumerates these nodes which reside in the respective front and
* backend portions of the XenStore, following the XenBus convention.
*
* Any specified default value is in effect if the corresponding XenBus node
* is not present in the XenStore.
*
* XenStore nodes in sections marked "PRIVATE" are solely for use by the
* driver side whose XenBus tree contains them.
*
*****************************************************************************
* Backend XenBus Nodes
*****************************************************************************
*
*------------------ Backend Device Identification (PRIVATE) ------------------
*
* num-ports
* Values: unsigned [1...31]
*
* Number of ports for this (virtual) USB host connector.
*
* usb-ver
* Values: unsigned [1...2]
*
* USB version of this host connector: 1 = USB 1.1, 2 = USB 2.0.
*
* port/[1...31]
* Values: string
*
* Physical USB device connected to the given port, e.g. "3-1.5".
*
*****************************************************************************
* Frontend XenBus Nodes
*****************************************************************************
*
*----------------------- Request Transport Parameters -----------------------
*
* event-channel
* Values: unsigned
*
* The identifier of the Xen event channel used to signal activity
* in the ring buffer.
*
* urb-ring-ref
* Values: unsigned
*
* The Xen grant reference granting permission for the backend to map
* the sole page in a single page sized ring buffer. This is the ring
* buffer for urb requests.
*
* conn-ring-ref
* Values: unsigned
*
* The Xen grant reference granting permission for the backend to map
* the sole page in a single page sized ring buffer. This is the ring
* buffer for connection/disconnection requests.
*
* protocol
* Values: string (XEN_IO_PROTO_ABI_*)
* Default Value: XEN_IO_PROTO_ABI_NATIVE
*
* The machine ABI rules governing the format of all ring request and
* response structures.
*
* Protocol Description
* ====================
*
*-------------------------- USB device plug events --------------------------
*
* USB device plug events are send via the "conn-ring" shared page. As only
* events are being sent, the respective requests from the frontend to the
* backend are just dummy ones.
* The events sent to the frontend have the following layout:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | portnum | speed | 4
* +----------------+----------------+----------------+----------------+
* id - uint16_t, event id (taken from the actual frontend dummy request)
* portnum - uint8_t, port number (1 ... 31)
* speed - uint8_t, device USBIF_SPEED_*, USBIF_SPEED_NONE == unplug
*
* The dummy request:
* 0 1 octet
* +----------------+----------------+
* | id | 2
* +----------------+----------------+
* id - uint16_t, guest supplied value (no need for being unique)
*
*-------------------------- USB I/O request ---------------------------------
*
* A single USB I/O request on the "urb-ring" has the following layout:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | nr_buffer_segs | 4
* +----------------+----------------+----------------+----------------+
* | pipe | 8
* +----------------+----------------+----------------+----------------+
* | transfer_flags | buffer_length | 12
* +----------------+----------------+----------------+----------------+
* | request type specific | 16
* | data | 20
* +----------------+----------------+----------------+----------------+
* | seg[0] | 24
* | data | 28
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | seg[USBIF_MAX_SEGMENTS_PER_REQUEST - 1] | 144
* | data | 148
* +----------------+----------------+----------------+----------------+
* Bit field bit number 0 is always least significant bit, undefined bits must
* be zero.
* id - uint16_t, guest supplied value
* nr_buffer_segs - uint16_t, number of segment entries in seg[] array
* pipe - uint32_t, bit field with multiple information:
* bits 0-4: port request to send to
* bit 5: unlink request with specified id (cancel I/O) if set (see below)
* bit 7: direction (1 = read from device)
* bits 8-14: device number on port
* bits 15-18: endpoint of device
* bits 30-31: request type: 00 = isochronous, 01 = interrupt,
* 10 = control, 11 = bulk
* transfer_flags - uint16_t, bit field with processing flags:
* bit 0: less data than specified allowed
* buffer_length - uint16_t, total length of data
* request type specific data - 8 bytes, see below
* seg[] - array with 8 byte elements, see below
*
* Request type specific data for isochronous request:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | interval | start_frame | 4
* +----------------+----------------+----------------+----------------+
* | number_of_packets | nr_frame_desc_segs | 8
* +----------------+----------------+----------------+----------------+
* interval - uint16_t, time interval in msecs between frames
* start_frame - uint16_t, start frame number
* number_of_packets - uint16_t, number of packets to transfer
* nr_frame_desc_segs - uint16_t number of seg[] frame descriptors elements
*
* Request type specific data for interrupt request:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | interval | 0 | 4
* +----------------+----------------+----------------+----------------+
* | 0 | 8
* +----------------+----------------+----------------+----------------+
* interval - uint16_t, time in msecs until interruption
*
* Request type specific data for control request:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | data of setup packet | 4
* | | 8
* +----------------+----------------+----------------+----------------+
*
* Request type specific data for bulk request:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | 0 | 4
* | 0 | 8
* +----------------+----------------+----------------+----------------+
*
* Request type specific data for unlink request:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | unlink_id | 0 | 4
* +----------------+----------------+----------------+----------------+
* | 0 | 8
* +----------------+----------------+----------------+----------------+
* unlink_id - uint16_t, request id of request to terminate
*
* seg[] array element layout:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | gref | 4
* +----------------+----------------+----------------+----------------+
* | offset | length | 8
* +----------------+----------------+----------------+----------------+
* gref - uint32_t, grant reference of buffer page
* offset - uint16_t, offset of buffer start in page
* length - uint16_t, length of buffer in page
*
*-------------------------- USB I/O response --------------------------------
*
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | start_frame | 4
* +----------------+----------------+----------------+----------------+
* | status | 8
* +----------------+----------------+----------------+----------------+
* | actual_length | 12
* +----------------+----------------+----------------+----------------+
* | error_count | 16
* +----------------+----------------+----------------+----------------+
* id - uint16_t, id of the request this response belongs to
* start_frame - uint16_t, start_frame this response (iso requests only)
* status - int32_t, USBIF_STATUS_* (non-iso requests)
* actual_length - uint32_t, actual size of data transferred
* error_count - uint32_t, number of errors (iso requests)
*/
enum usb_spec_version {
USB_VER_UNKNOWN = 0,
USB_VER_USB11,
USB_VER_USB20,
USB_VER_USB30, /* not supported yet */
};
/*
* USB pipe in usbif_request
*
* - port number: bits 0-4
* (USB_MAXCHILDREN is 31)
*
* - operation flag: bit 5
* (0 = submit urb,
* 1 = unlink urb)
*
* - direction: bit 7
* (0 = Host-to-Device [Out]
* 1 = Device-to-Host [In])
*
* - device address: bits 8-14
*
* - endpoint: bits 15-18
*
* - pipe type: bits 30-31
* (00 = isochronous, 01 = interrupt,
* 10 = control, 11 = bulk)
*/
#define USBIF_PIPE_PORT_MASK 0x0000001f
#define USBIF_PIPE_UNLINK 0x00000020
#define USBIF_PIPE_DIR 0x00000080
#define USBIF_PIPE_DEV_MASK 0x0000007f
#define USBIF_PIPE_DEV_SHIFT 8
#define USBIF_PIPE_EP_MASK 0x0000000f
#define USBIF_PIPE_EP_SHIFT 15
#define USBIF_PIPE_TYPE_MASK 0x00000003
#define USBIF_PIPE_TYPE_SHIFT 30
#define USBIF_PIPE_TYPE_ISOC 0
#define USBIF_PIPE_TYPE_INT 1
#define USBIF_PIPE_TYPE_CTRL 2
#define USBIF_PIPE_TYPE_BULK 3
#define usbif_pipeportnum(pipe) ((pipe) & USBIF_PIPE_PORT_MASK)
#define usbif_setportnum_pipe(pipe, portnum) ((pipe) | (portnum))
#define usbif_pipeunlink(pipe) ((pipe) & USBIF_PIPE_UNLINK)
#define usbif_pipesubmit(pipe) (!usbif_pipeunlink(pipe))
#define usbif_setunlink_pipe(pipe) ((pipe) | USBIF_PIPE_UNLINK)
#define usbif_pipein(pipe) ((pipe) & USBIF_PIPE_DIR)
#define usbif_pipeout(pipe) (!usbif_pipein(pipe))
#define usbif_pipedevice(pipe) \
(((pipe) >> USBIF_PIPE_DEV_SHIFT) & USBIF_PIPE_DEV_MASK)
#define usbif_pipeendpoint(pipe) \
(((pipe) >> USBIF_PIPE_EP_SHIFT) & USBIF_PIPE_EP_MASK)
#define usbif_pipetype(pipe) \
(((pipe) >> USBIF_PIPE_TYPE_SHIFT) & USBIF_PIPE_TYPE_MASK)
#define usbif_pipeisoc(pipe) (usbif_pipetype(pipe) == USBIF_PIPE_TYPE_ISOC)
#define usbif_pipeint(pipe) (usbif_pipetype(pipe) == USBIF_PIPE_TYPE_INT)
#define usbif_pipectrl(pipe) (usbif_pipetype(pipe) == USBIF_PIPE_TYPE_CTRL)
#define usbif_pipebulk(pipe) (usbif_pipetype(pipe) == USBIF_PIPE_TYPE_BULK)
#define USBIF_MAX_SEGMENTS_PER_REQUEST (16)
#define USBIF_MAX_PORTNR 31
#define USBIF_RING_SIZE 4096
/*
* RING for transferring urbs.
*/
struct usbif_request_segment {
grant_ref_t gref;
uint16_t offset;
uint16_t length;
};
struct usbif_urb_request {
uint16_t id; /* request id */
uint16_t nr_buffer_segs; /* number of urb->transfer_buffer segments */
/* basic urb parameter */
uint32_t pipe;
uint16_t transfer_flags;
#define USBIF_SHORT_NOT_OK 0x0001
uint16_t buffer_length;
union {
uint8_t ctrl[8]; /* setup_packet (Ctrl) */
struct {
uint16_t interval; /* maximum (1024*8) in usb core */
uint16_t start_frame; /* start frame */
uint16_t number_of_packets; /* number of ISO packet */
uint16_t nr_frame_desc_segs; /* number of iso_frame_desc segments */
} isoc;
struct {
uint16_t interval; /* maximum (1024*8) in usb core */
uint16_t pad[3];
} intr;
struct {
uint16_t unlink_id; /* unlink request id */
uint16_t pad[3];
} unlink;
} u;
/* urb data segments */
struct usbif_request_segment seg[USBIF_MAX_SEGMENTS_PER_REQUEST];
};
typedef struct usbif_urb_request usbif_urb_request_t;
struct usbif_urb_response {
uint16_t id; /* request id */
uint16_t start_frame; /* start frame (ISO) */
int32_t status; /* status (non-ISO) */
#define USBIF_STATUS_OK 0
#define USBIF_STATUS_NODEV (-19)
#define USBIF_STATUS_INVAL (-22)
#define USBIF_STATUS_STALL (-32)
#define USBIF_STATUS_IOERROR (-71)
#define USBIF_STATUS_BABBLE (-75)
#define USBIF_STATUS_SHUTDOWN (-108)
int32_t actual_length; /* actual transfer length */
int32_t error_count; /* number of ISO errors */
};
typedef struct usbif_urb_response usbif_urb_response_t;
DEFINE_RING_TYPES(usbif_urb, struct usbif_urb_request, struct usbif_urb_response);
#define USB_URB_RING_SIZE __CONST_RING_SIZE(usbif_urb, USBIF_RING_SIZE)
/*
* RING for notifying connect/disconnect events to frontend
*/
struct usbif_conn_request {
uint16_t id;
};
typedef struct usbif_conn_request usbif_conn_request_t;
struct usbif_conn_response {
uint16_t id; /* request id */
uint8_t portnum; /* port number */
uint8_t speed; /* usb_device_speed */
#define USBIF_SPEED_NONE 0
#define USBIF_SPEED_LOW 1
#define USBIF_SPEED_FULL 2
#define USBIF_SPEED_HIGH 3
};
typedef struct usbif_conn_response usbif_conn_response_t;
DEFINE_RING_TYPES(usbif_conn, struct usbif_conn_request, struct usbif_conn_response);
#define USB_CONN_RING_SIZE __CONST_RING_SIZE(usbif_conn, USBIF_RING_SIZE)
#endif /* __XEN_PUBLIC_IO_USBIF_H__ */