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

   1 /*
   2  * kbdif.h -- Xen virtual keyboard/mouse
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to
   6  * deal in the Software without restriction, including without limitation the
   7  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   8  * sell copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  20  * DEALINGS IN THE SOFTWARE.
  21  *
  22  * Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
  23  * Copyright (C) 2006 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
  24  */
  25
  26 #ifndef __XEN_PUBLIC_IO_KBDIF_H__
  27 #define __XEN_PUBLIC_IO_KBDIF_H__
  28
  29 /*
  30  *****************************************************************************
  31  *                     Feature and Parameter Negotiation
  32  *****************************************************************************
  33  *
  34  * The two halves of a para-virtual driver utilize nodes within
  35  * XenStore to communicate capabilities and to negotiate operating parameters.
  36  * This section enumerates these nodes which reside in the respective front and
  37  * backend portions of XenStore, following XenBus convention.
  38  *
  39  * All data in XenStore is stored as strings.  Nodes specifying numeric
  40  * values are encoded in decimal. Integer value ranges listed below are
  41  * expressed as fixed sized integer types capable of storing the conversion
  42  * of a properly formated node string, without loss of information.
  43  *
  44  *****************************************************************************
  45  *                            Backend XenBus Nodes
  46  *****************************************************************************
  47  *
  48  *---------------------------- Features supported ----------------------------
  49  *
  50  * Capable backend advertises supported features by publishing
  51  * corresponding entries in XenStore and puts 1 as the value of the entry.
  52  * If a feature is not supported then 0 must be set or feature entry omitted.
  53  *
  54  * feature-disable-keyboard
  55  *      Values:         <uint>
  56  *
  57  *      If there is no need to expose a virtual keyboard device by the
  58  *      frontend then this must be set to 1.
  59  *
  60  * feature-disable-pointer
  61  *      Values:         <uint>
  62  *
  63  *      If there is no need to expose a virtual pointer device by the
  64  *      frontend then this must be set to 1.
  65  *
  66  * feature-abs-pointer
  67  *      Values:         <uint>
  68  *
  69  *      Backends, which support reporting of absolute coordinates for pointer
  70  *      device should set this to 1.
  71  *
  72  * feature-multi-touch
  73  *      Values:         <uint>
  74  *
  75  *      Backends, which support reporting of multi-touch events
  76  *      should set this to 1.
  77  *
  78  * feature-raw-pointer
  79  *      Values:        <uint>
  80  *
  81  *      Backends, which support reporting raw (unscaled) absolute coordinates
  82  *      for pointer devices should set this to 1. Raw (unscaled) values have
  83  *      a range of [0, 0x7fff].
  84  *
  85  *-----------------------  Device Instance Parameters ------------------------
  86  *
  87  * unique-id
  88  *      Values:         <string>
  89  *
  90  *      After device instance initialization it is assigned a unique ID,
  91  *      so every instance of the frontend can be identified by the backend
  92  *      by this ID. This can be UUID or such.
  93  *
  94  *------------------------- Pointer Device Parameters ------------------------
  95  *
  96  * width
  97  *      Values:         <uint>
  98  *
  99  *      Maximum X coordinate (width) to be used by the frontend
 100  *      while reporting input events, pixels, [0; UINT32_MAX].
 101  *
 102  * height
 103  *      Values:         <uint>
 104  *
 105  *      Maximum Y coordinate (height) to be used by the frontend
 106  *      while reporting input events, pixels, [0; UINT32_MAX].
 107  *
 108  *----------------------- Multi-touch Device Parameters ----------------------
 109  *
 110  * multi-touch-num-contacts
 111  *      Values:         <uint>
 112  *
 113  *      Number of simultaneous touches reported.
 114  *
 115  * multi-touch-width
 116  *      Values:         <uint>
 117  *
 118  *      Width of the touch area to be used by the frontend
 119  *      while reporting input events, pixels, [0; UINT32_MAX].
 120  *
 121  * multi-touch-height
 122  *      Values:         <uint>
 123  *
 124  *      Height of the touch area to be used by the frontend
 125  *      while reporting input events, pixels, [0; UINT32_MAX].
 126  *
 127  *****************************************************************************
 128  *                            Frontend XenBus Nodes
 129  *****************************************************************************
 130  *
 131  *------------------------------ Feature request -----------------------------
 132  *
 133  * Capable frontend requests features from backend via setting corresponding
 134  * entries to 1 in XenStore. Requests for features not advertised as supported
 135  * by the backend have no effect.
 136  *
 137  * request-abs-pointer
 138  *      Values:         <uint>
 139  *
 140  *      Request backend to report absolute pointer coordinates
 141  *      (XENKBD_TYPE_POS) instead of relative ones (XENKBD_TYPE_MOTION).
 142  *
 143  * request-multi-touch
 144  *      Values:         <uint>
 145  *
 146  *      Request backend to report multi-touch events.
 147  *
 148  * request-raw-pointer
 149  *      Values:         <uint>
 150  *
 151  *      Request backend to report raw unscaled absolute pointer coordinates.
 152  *      This option is only valid if request-abs-pointer is also set.
 153  *      Raw unscaled coordinates have the range [0, 0x7fff]
 154  *
 155  *----------------------- Request Transport Parameters -----------------------
 156  *
 157  * event-channel
 158  *      Values:         <uint>
 159  *
 160  *      The identifier of the Xen event channel used to signal activity
 161  *      in the ring buffer.
 162  *
 163  * page-gref
 164  *      Values:         <uint>
 165  *
 166  *      The Xen grant reference granting permission for the backend to map
 167  *      a sole page in a single page sized event ring buffer.
 168  *
 169  * page-ref
 170  *      Values:         <uint>
 171  *
 172  *      OBSOLETE, not recommended for use.
 173  *      PFN of the shared page.
 174  */
 175
 176 /*
 177  * EVENT CODES.
 178  */
 179
 180 #define XENKBD_TYPE_MOTION             1
 181 #define XENKBD_TYPE_RESERVED           2
 182 #define XENKBD_TYPE_KEY                3
 183 #define XENKBD_TYPE_POS                4
 184 #define XENKBD_TYPE_MTOUCH             5
 185
 186 /* Multi-touch event sub-codes */
 187
 188 #define XENKBD_MT_EV_DOWN              0
 189 #define XENKBD_MT_EV_UP                1
 190 #define XENKBD_MT_EV_MOTION            2
 191 #define XENKBD_MT_EV_SYN               3
 192 #define XENKBD_MT_EV_SHAPE             4
 193 #define XENKBD_MT_EV_ORIENT            5
 194
 195 /*
 196  * CONSTANTS, XENSTORE FIELD AND PATH NAME STRINGS, HELPERS.
 197  */
 198
 199 #define XENKBD_DRIVER_NAME             "vkbd"
 200
 201 #define XENKBD_FIELD_FEAT_DSBL_KEYBRD  "feature-disable-keyboard"
 202 #define XENKBD_FIELD_FEAT_DSBL_POINTER "feature-disable-pointer"
 203 #define XENKBD_FIELD_FEAT_ABS_POINTER  "feature-abs-pointer"
 204 #define XENKBD_FIELD_FEAT_RAW_POINTER  "feature-raw-pointer"
 205 #define XENKBD_FIELD_FEAT_MTOUCH       "feature-multi-touch"
 206 #define XENKBD_FIELD_REQ_ABS_POINTER   "request-abs-pointer"
 207 #define XENKBD_FIELD_REQ_RAW_POINTER   "request-raw-pointer"
 208 #define XENKBD_FIELD_REQ_MTOUCH        "request-multi-touch"
 209 #define XENKBD_FIELD_RING_GREF         "page-gref"
 210 #define XENKBD_FIELD_EVT_CHANNEL       "event-channel"
 211 #define XENKBD_FIELD_WIDTH             "width"
 212 #define XENKBD_FIELD_HEIGHT            "height"
 213 #define XENKBD_FIELD_MT_WIDTH          "multi-touch-width"
 214 #define XENKBD_FIELD_MT_HEIGHT         "multi-touch-height"
 215 #define XENKBD_FIELD_MT_NUM_CONTACTS   "multi-touch-num-contacts"
 216 #define XENKBD_FIELD_UNIQUE_ID         "unique-id"
 217
 218 /* OBSOLETE, not recommended for use */
 219 #define XENKBD_FIELD_RING_REF          "page-ref"
 220
 221 /*
 222  *****************************************************************************
 223  * Description of the protocol between frontend and backend driver.
 224  *****************************************************************************
 225  *
 226  * The two halves of a Para-virtual driver communicate with
 227  * each other using a shared page and an event channel.
 228  * Shared page contains a ring with event structures.
 229  *
 230  * All reserved fields in the structures below must be 0.
 231  *
 232  *****************************************************************************
 233  *                           Backend to frontend events
 234  *****************************************************************************
 235  *
 236  * Frontends should ignore unknown in events.
 237  * All event packets have the same length (40 octets)
 238  * All event packets have common header:
 239  *
 240  *          0         octet
 241  * +-----------------+
 242  * |       type      |
 243  * +-----------------+
 244  * type - uint8_t, event code, XENKBD_TYPE_???
 245  *
 246  *
 247  * Pointer relative movement event
 248  *         0                1                 2               3        octet
 249  * +----------------+----------------+----------------+----------------+
 250  * |  _TYPE_MOTION  |                     reserved                     | 4
 251  * +----------------+----------------+----------------+----------------+
 252  * |                               rel_x                               | 8
 253  * +----------------+----------------+----------------+----------------+
 254  * |                               rel_y                               | 12
 255  * +----------------+----------------+----------------+----------------+
 256  * |                               rel_z                               | 16
 257  * +----------------+----------------+----------------+----------------+
 258  * |                             reserved                              | 20
 259  * +----------------+----------------+----------------+----------------+
 260  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 261  * +----------------+----------------+----------------+----------------+
 262  * |                             reserved                              | 40
 263  * +----------------+----------------+----------------+----------------+
 264  *
 265  * rel_x - int32_t, relative X motion
 266  * rel_y - int32_t, relative Y motion
 267  * rel_z - int32_t, relative Z motion (wheel)
 268  */
 269
 270 struct xenkbd_motion
 271 {
 272     uint8_t type;
 273     int32_t rel_x;
 274     int32_t rel_y;
 275     int32_t rel_z;
 276 };
 277
 278 /*
 279  * Key event (includes pointer buttons)
 280  *         0                1                 2               3        octet
 281  * +----------------+----------------+----------------+----------------+
 282  * |  _TYPE_KEY     |     pressed    |            reserved             | 4
 283  * +----------------+----------------+----------------+----------------+
 284  * |                              keycode                              | 8
 285  * +----------------+----------------+----------------+----------------+
 286  * |                             reserved                              | 12
 287  * +----------------+----------------+----------------+----------------+
 288  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 289  * +----------------+----------------+----------------+----------------+
 290  * |                             reserved                              | 40
 291  * +----------------+----------------+----------------+----------------+
 292  *
 293  * pressed - uint8_t, 1 if pressed; 0 otherwise
 294  * keycode - uint32_t, KEY_* from linux/input.h
 295  */
 296
 297 struct xenkbd_key
 298 {
 299     uint8_t type;
 300     uint8_t pressed;
 301     uint32_t keycode;
 302 };
 303
 304 /*
 305  * Pointer absolute position event
 306  *         0                1                 2               3        octet
 307  * +----------------+----------------+----------------+----------------+
 308  * |  _TYPE_POS     |                     reserved                     | 4
 309  * +----------------+----------------+----------------+----------------+
 310  * |                               abs_x                               | 8
 311  * +----------------+----------------+----------------+----------------+
 312  * |                               abs_y                               | 12
 313  * +----------------+----------------+----------------+----------------+
 314  * |                               rel_z                               | 16
 315  * +----------------+----------------+----------------+----------------+
 316  * |                             reserved                              | 20
 317  * +----------------+----------------+----------------+----------------+
 318  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 319  * +----------------+----------------+----------------+----------------+
 320  * |                             reserved                              | 40
 321  * +----------------+----------------+----------------+----------------+
 322  *
 323  * abs_x - int32_t, absolute X position (in FB pixels)
 324  * abs_y - int32_t, absolute Y position (in FB pixels)
 325  * rel_z - int32_t, relative Z motion (wheel)
 326  */
 327
 328 struct xenkbd_position
 329 {
 330     uint8_t type;
 331     int32_t abs_x;
 332     int32_t abs_y;
 333     int32_t rel_z;
 334 };
 335
 336 /*
 337  * Multi-touch event and its sub-types
 338  *
 339  * All multi-touch event packets have common header:
 340  *
 341  *         0                1                 2               3        octet
 342  * +----------------+----------------+----------------+----------------+
 343  * |  _TYPE_MTOUCH  |   event_type   |   contact_id   |    reserved    | 4
 344  * +----------------+----------------+----------------+----------------+
 345  * |                             reserved                              | 8
 346  * +----------------+----------------+----------------+----------------+
 347  *
 348  * event_type - unt8_t, multi-touch event sub-type, XENKBD_MT_EV_???
 349  * contact_id - unt8_t, ID of the contact
 350  *
 351  * Touch interactions can consist of one or more contacts.
 352  * For each contact, a series of events is generated, starting
 353  * with a down event, followed by zero or more motion events,
 354  * and ending with an up event. Events relating to the same
 355  * contact point can be identified by the ID of the sequence: contact ID.
 356  * Contact ID may be reused after XENKBD_MT_EV_UP event and
 357  * is in the [0; XENKBD_FIELD_NUM_CONTACTS - 1] range.
 358  *
 359  * For further information please refer to documentation on Wayland [1],
 360  * Linux [2] and Windows [3] multi-touch support.
 361  *
 362  * [1] https://cgit.freedesktop.org/wayland/wayland/tree/protocol/wayland.xml
 363  * [2] https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.txt
 364  * [3] https://msdn.microsoft.com/en-us/library/jj151564(v=vs.85).aspx
 365  *
 366  *
 367  * Multi-touch down event - sent when a new touch is made: touch is assigned
 368  * a unique contact ID, sent with this and consequent events related
 369  * to this touch.
 370  *         0                1                 2               3        octet
 371  * +----------------+----------------+----------------+----------------+
 372  * |  _TYPE_MTOUCH  |   _MT_EV_DOWN  |   contact_id   |    reserved    | 4
 373  * +----------------+----------------+----------------+----------------+
 374  * |                             reserved                              | 8
 375  * +----------------+----------------+----------------+----------------+
 376  * |                               abs_x                               | 12
 377  * +----------------+----------------+----------------+----------------+
 378  * |                               abs_y                               | 16
 379  * +----------------+----------------+----------------+----------------+
 380  * |                             reserved                              | 20
 381  * +----------------+----------------+----------------+----------------+
 382  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 383  * +----------------+----------------+----------------+----------------+
 384  * |                             reserved                              | 40
 385  * +----------------+----------------+----------------+----------------+
 386  *
 387  * abs_x - int32_t, absolute X position, in pixels
 388  * abs_y - int32_t, absolute Y position, in pixels
 389  *
 390  * Multi-touch contact release event
 391  *         0                1                 2               3        octet
 392  * +----------------+----------------+----------------+----------------+
 393  * |  _TYPE_MTOUCH  |  _MT_EV_UP     |   contact_id   |    reserved    | 4
 394  * +----------------+----------------+----------------+----------------+
 395  * |                             reserved                              | 8
 396  * +----------------+----------------+----------------+----------------+
 397  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 398  * +----------------+----------------+----------------+----------------+
 399  * |                             reserved                              | 40
 400  * +----------------+----------------+----------------+----------------+
 401  *
 402  * Multi-touch motion event
 403  *         0                1                 2               3        octet
 404  * +----------------+----------------+----------------+----------------+
 405  * |  _TYPE_MTOUCH  |  _MT_EV_MOTION |   contact_id   |    reserved    | 4
 406  * +----------------+----------------+----------------+----------------+
 407  * |                             reserved                              | 8
 408  * +----------------+----------------+----------------+----------------+
 409  * |                               abs_x                               | 12
 410  * +----------------+----------------+----------------+----------------+
 411  * |                               abs_y                               | 16
 412  * +----------------+----------------+----------------+----------------+
 413  * |                             reserved                              | 20
 414  * +----------------+----------------+----------------+----------------+
 415  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 416  * +----------------+----------------+----------------+----------------+
 417  * |                             reserved                              | 40
 418  * +----------------+----------------+----------------+----------------+
 419  *
 420  * abs_x - int32_t, absolute X position, in pixels,
 421  * abs_y - int32_t, absolute Y position, in pixels,
 422  *
 423  * Multi-touch input synchronization event - shows end of a set of events
 424  * which logically belong together.
 425  *         0                1                 2               3        octet
 426  * +----------------+----------------+----------------+----------------+
 427  * |  _TYPE_MTOUCH  |  _MT_EV_SYN    |   contact_id   |    reserved    | 4
 428  * +----------------+----------------+----------------+----------------+
 429  * |                             reserved                              | 8
 430  * +----------------+----------------+----------------+----------------+
 431  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 432  * +----------------+----------------+----------------+----------------+
 433  * |                             reserved                              | 40
 434  * +----------------+----------------+----------------+----------------+
 435  *
 436  * Multi-touch shape event - touch point's shape has changed its shape.
 437  * Shape is approximated by an ellipse through the major and minor axis
 438  * lengths: major is the longer diameter of the ellipse and minor is the
 439  * shorter one. Center of the ellipse is reported via
 440  * XENKBD_MT_EV_DOWN/XENKBD_MT_EV_MOTION events.
 441  *         0                1                 2               3        octet
 442  * +----------------+----------------+----------------+----------------+
 443  * |  _TYPE_MTOUCH  |  _MT_EV_SHAPE  |   contact_id   |    reserved    | 4
 444  * +----------------+----------------+----------------+----------------+
 445  * |                             reserved                              | 8
 446  * +----------------+----------------+----------------+----------------+
 447  * |                               major                               | 12
 448  * +----------------+----------------+----------------+----------------+
 449  * |                               minor                               | 16
 450  * +----------------+----------------+----------------+----------------+
 451  * |                             reserved                              | 20
 452  * +----------------+----------------+----------------+----------------+
 453  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 454  * +----------------+----------------+----------------+----------------+
 455  * |                             reserved                              | 40
 456  * +----------------+----------------+----------------+----------------+
 457  *
 458  * major - unt32_t, length of the major axis, pixels
 459  * minor - unt32_t, length of the minor axis, pixels
 460  *
 461  * Multi-touch orientation event - touch point's shape has changed
 462  * its orientation: calculated as a clockwise angle between the major axis
 463  * of the ellipse and positive Y axis in degrees, [-180; +180].
 464  *         0                1                 2               3        octet
 465  * +----------------+----------------+----------------+----------------+
 466  * |  _TYPE_MTOUCH  |  _MT_EV_ORIENT |   contact_id   |    reserved    | 4
 467  * +----------------+----------------+----------------+----------------+
 468  * |                             reserved                              | 8
 469  * +----------------+----------------+----------------+----------------+
 470  * |           orientation           |            reserved             | 12
 471  * +----------------+----------------+----------------+----------------+
 472  * |                             reserved                              | 16
 473  * +----------------+----------------+----------------+----------------+
 474  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 475  * +----------------+----------------+----------------+----------------+
 476  * |                             reserved                              | 40
 477  * +----------------+----------------+----------------+----------------+
 478  *
 479  * orientation - int16_t, clockwise angle of the major axis
 480  */
 481
 482 struct xenkbd_mtouch {
 483     uint8_t type;            /* XENKBD_TYPE_MTOUCH */
 484     uint8_t event_type;      /* XENKBD_MT_EV_??? */
 485     uint8_t contact_id;
 486     uint8_t reserved[5];     /* reserved for the future use */
 487     union {
 488         struct {
 489             int32_t abs_x;   /* absolute X position, pixels */
 490             int32_t abs_y;   /* absolute Y position, pixels */
 491         } pos;
 492         struct {
 493             uint32_t major;  /* length of the major axis, pixels */
 494             uint32_t minor;  /* length of the minor axis, pixels */
 495         } shape;
 496         int16_t orientation; /* clockwise angle of the major axis */
 497     } u;
 498 };
 499
 500 #define XENKBD_IN_EVENT_SIZE 40
 501
 502 union xenkbd_in_event
 503 {
 504     uint8_t type;
 505     struct xenkbd_motion motion;
 506     struct xenkbd_key key;
 507     struct xenkbd_position pos;
 508     struct xenkbd_mtouch mtouch;
 509     char pad[XENKBD_IN_EVENT_SIZE];
 510 };
 511
 512 /*
 513  *****************************************************************************
 514  *                            Frontend to backend events
 515  *****************************************************************************
 516  *
 517  * Out events may be sent only when requested by backend, and receipt
 518  * of an unknown out event is an error.
 519  * No out events currently defined.
 520
 521  * All event packets have the same length (40 octets)
 522  * All event packets have common header:
 523  *          0         octet
 524  * +-----------------+
 525  * |       type      |
 526  * +-----------------+
 527  * type - uint8_t, event code
 528  */
 529
 530 #define XENKBD_OUT_EVENT_SIZE 40
 531
 532 union xenkbd_out_event
 533 {
 534     uint8_t type;
 535     char pad[XENKBD_OUT_EVENT_SIZE];
 536 };
 537
 538 /*
 539  *****************************************************************************
 540  *                            Shared page
 541  *****************************************************************************
 542  */
 543
 544 #define XENKBD_IN_RING_SIZE 2048
 545 #define XENKBD_IN_RING_LEN (XENKBD_IN_RING_SIZE / XENKBD_IN_EVENT_SIZE)
 546 #define XENKBD_IN_RING_OFFS 1024
 547 #define XENKBD_IN_RING(page) \
 548     ((union xenkbd_in_event *)((char *)(page) + XENKBD_IN_RING_OFFS))
 549 #define XENKBD_IN_RING_REF(page, idx) \
 550     (XENKBD_IN_RING((page))[(idx) % XENKBD_IN_RING_LEN])
 551
 552 #define XENKBD_OUT_RING_SIZE 1024
 553 #define XENKBD_OUT_RING_LEN (XENKBD_OUT_RING_SIZE / XENKBD_OUT_EVENT_SIZE)
 554 #define XENKBD_OUT_RING_OFFS (XENKBD_IN_RING_OFFS + XENKBD_IN_RING_SIZE)
 555 #define XENKBD_OUT_RING(page) \
 556     ((union xenkbd_out_event *)((char *)(page) + XENKBD_OUT_RING_OFFS))
 557 #define XENKBD_OUT_RING_REF(page, idx) \
 558     (XENKBD_OUT_RING((page))[(idx) % XENKBD_OUT_RING_LEN])
 559
 560 struct xenkbd_page
 561 {
 562     uint32_t in_cons, in_prod;
 563     uint32_t out_cons, out_prod;
 564 };
 565
 566 #endif /* __XEN_PUBLIC_IO_KBDIF_H__ */