include/hw/xen/interface/io/usbif.h

   1 /* SPDX-License-Identifier: MIT */
   2 /*
   3  * usbif.h
   4  *
   5  * USB I/O interface for Xen guest OSes.
   6  *
   7  * Copyright (C) 2009, FUJITSU LABORATORIES LTD.
   8  * Author: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
   9  */
  10
  11 #ifndef __XEN_PUBLIC_IO_USBIF_H__
  12 #define __XEN_PUBLIC_IO_USBIF_H__
  13
  14 #include "ring.h"
  15 #include "../grant_table.h"
  16
  17 /*
  18  * Detailed Interface Description
  19  * ==============================
  20  * The pvUSB interface is using a split driver design: a frontend driver in
  21  * the guest and a backend driver in a driver domain (normally dom0) having
  22  * access to the physical USB device(s) being passed to the guest.
  23  *
  24  * The frontend and backend drivers use XenStore to initiate the connection
  25  * between them, the I/O activity is handled via two shared ring pages and an
  26  * event channel. As the interface between frontend and backend is at the USB
  27  * host connector level, multiple (up to 31) physical USB devices can be
  28  * handled by a single connection.
  29  *
  30  * The Xen pvUSB device name is "qusb", so the frontend's XenStore entries are
  31  * to be found under "device/qusb", while the backend's XenStore entries are
  32  * under "backend/<guest-dom-id>/qusb".
  33  *
  34  * When a new pvUSB connection is established, the frontend needs to setup the
  35  * two shared ring pages for communication and the event channel. The ring
  36  * pages need to be made available to the backend via the grant table
  37  * interface.
  38  *
  39  * One of the shared ring pages is used by the backend to inform the frontend
  40  * about USB device plug events (device to be added or removed). This is the
  41  * "conn-ring".
  42  *
  43  * The other ring page is used for USB I/O communication (requests and
  44  * responses). This is the "urb-ring".
  45  *
  46  * Feature and Parameter Negotiation
  47  * =================================
  48  * The two halves of a Xen pvUSB driver utilize nodes within the XenStore to
  49  * communicate capabilities and to negotiate operating parameters. This
  50  * section enumerates these nodes which reside in the respective front and
  51  * backend portions of the XenStore, following the XenBus convention.
  52  *
  53  * Any specified default value is in effect if the corresponding XenBus node
  54  * is not present in the XenStore.
  55  *
  56  * XenStore nodes in sections marked "PRIVATE" are solely for use by the
  57  * driver side whose XenBus tree contains them.
  58  *
  59  *****************************************************************************
  60  *                            Backend XenBus Nodes
  61  *****************************************************************************
  62  *
  63  *------------------ Backend Device Identification (PRIVATE) ------------------
  64  *
  65  * num-ports
  66  *      Values:         unsigned [1...31]
  67  *
  68  *      Number of ports for this (virtual) USB host connector.
  69  *
  70  * usb-ver
  71  *      Values:         unsigned [1...2]
  72  *
  73  *      USB version of this host connector: 1 = USB 1.1, 2 = USB 2.0.
  74  *
  75  * port/[1...31]
  76  *      Values:         string
  77  *
  78  *      Physical USB device connected to the given port, e.g. "3-1.5".
  79  *
  80  *****************************************************************************
  81  *                            Frontend XenBus Nodes
  82  *****************************************************************************
  83  *
  84  *----------------------- Request Transport Parameters -----------------------
  85  *
  86  * event-channel
  87  *      Values:         unsigned
  88  *
  89  *      The identifier of the Xen event channel used to signal activity
  90  *      in the ring buffer.
  91  *
  92  * urb-ring-ref
  93  *      Values:         unsigned
  94  *
  95  *      The Xen grant reference granting permission for the backend to map
  96  *      the sole page in a single page sized ring buffer. This is the ring
  97  *      buffer for urb requests.
  98  *
  99  * conn-ring-ref
 100  *      Values:         unsigned
 101  *
 102  *      The Xen grant reference granting permission for the backend to map
 103  *      the sole page in a single page sized ring buffer. This is the ring
 104  *      buffer for connection/disconnection requests.
 105  *
 106  * protocol
 107  *      Values:         string (XEN_IO_PROTO_ABI_*)
 108  *      Default Value:  XEN_IO_PROTO_ABI_NATIVE
 109  *
 110  *      The machine ABI rules governing the format of all ring request and
 111  *      response structures.
 112  *
 113  * Protocol Description
 114  * ====================
 115  *
 116  *-------------------------- USB device plug events --------------------------
 117  *
 118  * USB device plug events are send via the "conn-ring" shared page. As only
 119  * events are being sent, the respective requests from the frontend to the
 120  * backend are just dummy ones.
 121  * The events sent to the frontend have the following layout:
 122  *         0                1                 2               3        octet
 123  * +----------------+----------------+----------------+----------------+
 124  * |               id                |    portnum     |     speed      | 4
 125  * +----------------+----------------+----------------+----------------+
 126  *   id - uint16_t, event id (taken from the actual frontend dummy request)
 127  *   portnum - uint8_t, port number (1 ... 31)
 128  *   speed - uint8_t, device USBIF_SPEED_*, USBIF_SPEED_NONE == unplug
 129  *
 130  * The dummy request:
 131  *         0                1        octet
 132  * +----------------+----------------+
 133  * |               id                | 2
 134  * +----------------+----------------+
 135  *   id - uint16_t, guest supplied value (no need for being unique)
 136  *
 137  *-------------------------- USB I/O request ---------------------------------
 138  *
 139  * A single USB I/O request on the "urb-ring" has the following layout:
 140  *         0                1                 2               3        octet
 141  * +----------------+----------------+----------------+----------------+
 142  * |               id                |         nr_buffer_segs          | 4
 143  * +----------------+----------------+----------------+----------------+
 144  * |                               pipe                                | 8
 145  * +----------------+----------------+----------------+----------------+
 146  * |         transfer_flags          |          buffer_length          | 12
 147  * +----------------+----------------+----------------+----------------+
 148  * |                       request type specific                       | 16
 149  * |                               data                                | 20
 150  * +----------------+----------------+----------------+----------------+
 151  * |                              seg[0]                               | 24
 152  * |                               data                                | 28
 153  * +----------------+----------------+----------------+----------------+
 154  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 155  * +----------------+----------------+----------------+----------------+
 156  * |             seg[USBIF_MAX_SEGMENTS_PER_REQUEST - 1]               | 144
 157  * |                               data                                | 148
 158  * +----------------+----------------+----------------+----------------+
 159  * Bit field bit number 0 is always least significant bit, undefined bits must
 160  * be zero.
 161  *   id - uint16_t, guest supplied value
 162  *   nr_buffer_segs - uint16_t, number of segment entries in seg[] array
 163  *   pipe - uint32_t, bit field with multiple information:
 164  *     bits 0-4: port request to send to
 165  *     bit 5: unlink request with specified id (cancel I/O) if set (see below)
 166  *     bit 7: direction (1 = read from device)
 167  *     bits 8-14: device number on port
 168  *     bits 15-18: endpoint of device
 169  *     bits 30-31: request type: 00 = isochronous, 01 = interrupt,
 170  *                               10 = control, 11 = bulk
 171  *   transfer_flags - uint16_t, bit field with processing flags:
 172  *     bit 0: less data than specified allowed
 173  *   buffer_length - uint16_t, total length of data
 174  *   request type specific data - 8 bytes, see below
 175  *   seg[] - array with 8 byte elements, see below
 176  *
 177  * Request type specific data for isochronous request:
 178  *         0                1                 2               3        octet
 179  * +----------------+----------------+----------------+----------------+
 180  * |            interval             |           start_frame           | 4
 181  * +----------------+----------------+----------------+----------------+
 182  * |       number_of_packets         |       nr_frame_desc_segs        | 8
 183  * +----------------+----------------+----------------+----------------+
 184  *   interval - uint16_t, time interval in msecs between frames
 185  *   start_frame - uint16_t, start frame number
 186  *   number_of_packets - uint16_t, number of packets to transfer
 187  *   nr_frame_desc_segs - uint16_t number of seg[] frame descriptors elements
 188  *
 189  * Request type specific data for interrupt request:
 190  *         0                1                 2               3        octet
 191  * +----------------+----------------+----------------+----------------+
 192  * |            interval             |                0                | 4
 193  * +----------------+----------------+----------------+----------------+
 194  * |                                 0                                 | 8
 195  * +----------------+----------------+----------------+----------------+
 196  *   interval - uint16_t, time in msecs until interruption
 197  *
 198  * Request type specific data for control request:
 199  *         0                1                 2               3        octet
 200  * +----------------+----------------+----------------+----------------+
 201  * |                      data of setup packet                         | 4
 202  * |                                                                   | 8
 203  * +----------------+----------------+----------------+----------------+
 204  *
 205  * Request type specific data for bulk request:
 206  *         0                1                 2               3        octet
 207  * +----------------+----------------+----------------+----------------+
 208  * |                                 0                                 | 4
 209  * |                                 0                                 | 8
 210  * +----------------+----------------+----------------+----------------+
 211  *
 212  * Request type specific data for unlink request:
 213  *         0                1                 2               3        octet
 214  * +----------------+----------------+----------------+----------------+
 215  * |           unlink_id             |                0                | 4
 216  * +----------------+----------------+----------------+----------------+
 217  * |                                 0                                 | 8
 218  * +----------------+----------------+----------------+----------------+
 219  *   unlink_id - uint16_t, request id of request to terminate
 220  *
 221  * seg[] array element layout:
 222  *         0                1                 2               3        octet
 223  * +----------------+----------------+----------------+----------------+
 224  * |                               gref                                | 4
 225  * +----------------+----------------+----------------+----------------+
 226  * |             offset              |             length              | 8
 227  * +----------------+----------------+----------------+----------------+
 228  *   gref - uint32_t, grant reference of buffer page
 229  *   offset - uint16_t, offset of buffer start in page
 230  *   length - uint16_t, length of buffer in page
 231  *
 232  *-------------------------- USB I/O response --------------------------------
 233  *
 234  *         0                1                 2               3        octet
 235  * +----------------+----------------+----------------+----------------+
 236  * |               id                |          start_frame            | 4
 237  * +----------------+----------------+----------------+----------------+
 238  * |                              status                               | 8
 239  * +----------------+----------------+----------------+----------------+
 240  * |                          actual_length                            | 12
 241  * +----------------+----------------+----------------+----------------+
 242  * |                           error_count                             | 16
 243  * +----------------+----------------+----------------+----------------+
 244  *   id - uint16_t, id of the request this response belongs to
 245  *   start_frame - uint16_t, start_frame this response (iso requests only)
 246  *   status - int32_t, USBIF_STATUS_* (non-iso requests)
 247  *   actual_length - uint32_t, actual size of data transferred
 248  *   error_count - uint32_t, number of errors (iso requests)
 249  */
 250
 251 enum usb_spec_version {
 252     USB_VER_UNKNOWN = 0,
 253     USB_VER_USB11,
 254     USB_VER_USB20,
 255     USB_VER_USB30,    /* not supported yet */
 256 };
 257
 258 /*
 259  *  USB pipe in usbif_request
 260  *
 261  *  - port number:      bits 0-4
 262  *                              (USB_MAXCHILDREN is 31)
 263  *
 264  *  - operation flag:   bit 5
 265  *                              (0 = submit urb,
 266  *                               1 = unlink urb)
 267  *
 268  *  - direction:        bit 7
 269  *                              (0 = Host-to-Device [Out]
 270  *                               1 = Device-to-Host [In])
 271  *
 272  *  - device address:   bits 8-14
 273  *
 274  *  - endpoint:         bits 15-18
 275  *
 276  *  - pipe type:        bits 30-31
 277  *                              (00 = isochronous, 01 = interrupt,
 278  *                               10 = control, 11 = bulk)
 279  */
 280
 281 #define USBIF_PIPE_PORT_MASK    0x0000001f
 282 #define USBIF_PIPE_UNLINK       0x00000020
 283 #define USBIF_PIPE_DIR          0x00000080
 284 #define USBIF_PIPE_DEV_MASK     0x0000007f
 285 #define USBIF_PIPE_DEV_SHIFT    8
 286 #define USBIF_PIPE_EP_MASK      0x0000000f
 287 #define USBIF_PIPE_EP_SHIFT     15
 288 #define USBIF_PIPE_TYPE_MASK    0x00000003
 289 #define USBIF_PIPE_TYPE_SHIFT   30
 290 #define USBIF_PIPE_TYPE_ISOC    0
 291 #define USBIF_PIPE_TYPE_INT     1
 292 #define USBIF_PIPE_TYPE_CTRL    2
 293 #define USBIF_PIPE_TYPE_BULK    3
 294
 295 #define usbif_pipeportnum(pipe)                 ((pipe) & USBIF_PIPE_PORT_MASK)
 296 #define usbif_setportnum_pipe(pipe, portnum)    ((pipe) | (portnum))
 297
 298 #define usbif_pipeunlink(pipe)                  ((pipe) & USBIF_PIPE_UNLINK)
 299 #define usbif_pipesubmit(pipe)                  (!usbif_pipeunlink(pipe))
 300 #define usbif_setunlink_pipe(pipe)              ((pipe) | USBIF_PIPE_UNLINK)
 301
 302 #define usbif_pipein(pipe)                      ((pipe) & USBIF_PIPE_DIR)
 303 #define usbif_pipeout(pipe)                     (!usbif_pipein(pipe))
 304
 305 #define usbif_pipedevice(pipe)                  \
 306         (((pipe) >> USBIF_PIPE_DEV_SHIFT) & USBIF_PIPE_DEV_MASK)
 307
 308 #define usbif_pipeendpoint(pipe)                \
 309         (((pipe) >> USBIF_PIPE_EP_SHIFT) & USBIF_PIPE_EP_MASK)
 310
 311 #define usbif_pipetype(pipe)                    \
 312         (((pipe) >> USBIF_PIPE_TYPE_SHIFT) & USBIF_PIPE_TYPE_MASK)
 313 #define usbif_pipeisoc(pipe)    (usbif_pipetype(pipe) == USBIF_PIPE_TYPE_ISOC)
 314 #define usbif_pipeint(pipe)     (usbif_pipetype(pipe) == USBIF_PIPE_TYPE_INT)
 315 #define usbif_pipectrl(pipe)    (usbif_pipetype(pipe) == USBIF_PIPE_TYPE_CTRL)
 316 #define usbif_pipebulk(pipe)    (usbif_pipetype(pipe) == USBIF_PIPE_TYPE_BULK)
 317
 318 #define USBIF_MAX_SEGMENTS_PER_REQUEST (16)
 319 #define USBIF_MAX_PORTNR        31
 320 #define USBIF_RING_SIZE         4096
 321
 322 /*
 323  * RING for transferring urbs.
 324  */
 325 struct usbif_request_segment {
 326     grant_ref_t gref;
 327     uint16_t offset;
 328     uint16_t length;
 329 };
 330
 331 struct usbif_urb_request {
 332     uint16_t id;                  /* request id */
 333     uint16_t nr_buffer_segs;      /* number of urb->transfer_buffer segments */
 334
 335     /* basic urb parameter */
 336     uint32_t pipe;
 337     uint16_t transfer_flags;
 338 #define USBIF_SHORT_NOT_OK      0x0001
 339     uint16_t buffer_length;
 340     union {
 341         uint8_t ctrl[8];                 /* setup_packet (Ctrl) */
 342
 343         struct {
 344             uint16_t interval;           /* maximum (1024*8) in usb core */
 345             uint16_t start_frame;        /* start frame */
 346             uint16_t number_of_packets;  /* number of ISO packet */
 347             uint16_t nr_frame_desc_segs; /* number of iso_frame_desc segments */
 348         } isoc;
 349
 350         struct {
 351             uint16_t interval;           /* maximum (1024*8) in usb core */
 352             uint16_t pad[3];
 353         } intr;
 354
 355         struct {
 356             uint16_t unlink_id;          /* unlink request id */
 357             uint16_t pad[3];
 358         } unlink;
 359
 360     } u;
 361
 362     /* urb data segments */
 363     struct usbif_request_segment seg[USBIF_MAX_SEGMENTS_PER_REQUEST];
 364 };
 365 typedef struct usbif_urb_request usbif_urb_request_t;
 366
 367 struct usbif_urb_response {
 368     uint16_t id;           /* request id */
 369     uint16_t start_frame;  /* start frame (ISO) */
 370     int32_t status;        /* status (non-ISO) */
 371 #define USBIF_STATUS_OK         0
 372 #define USBIF_STATUS_NODEV      (-19)
 373 #define USBIF_STATUS_INVAL      (-22)
 374 #define USBIF_STATUS_STALL      (-32)
 375 #define USBIF_STATUS_IOERROR    (-71)
 376 #define USBIF_STATUS_BABBLE     (-75)
 377 #define USBIF_STATUS_SHUTDOWN   (-108)
 378     int32_t actual_length; /* actual transfer length */
 379     int32_t error_count;   /* number of ISO errors */
 380 };
 381 typedef struct usbif_urb_response usbif_urb_response_t;
 382
 383 DEFINE_RING_TYPES(usbif_urb, struct usbif_urb_request, struct usbif_urb_response);
 384 #define USB_URB_RING_SIZE __CONST_RING_SIZE(usbif_urb, USBIF_RING_SIZE)
 385
 386 /*
 387  * RING for notifying connect/disconnect events to frontend
 388  */
 389 struct usbif_conn_request {
 390     uint16_t id;
 391 };
 392 typedef struct usbif_conn_request usbif_conn_request_t;
 393
 394 struct usbif_conn_response {
 395     uint16_t id;           /* request id */
 396     uint8_t portnum;       /* port number */
 397     uint8_t speed;         /* usb_device_speed */
 398 #define USBIF_SPEED_NONE        0
 399 #define USBIF_SPEED_LOW         1
 400 #define USBIF_SPEED_FULL        2
 401 #define USBIF_SPEED_HIGH        3
 402 };
 403 typedef struct usbif_conn_response usbif_conn_response_t;
 404
 405 DEFINE_RING_TYPES(usbif_conn, struct usbif_conn_request, struct usbif_conn_response);
 406 #define USB_CONN_RING_SIZE __CONST_RING_SIZE(usbif_conn, USBIF_RING_SIZE)
 407
 408 #endif /* __XEN_PUBLIC_IO_USBIF_H__ */