drivers/uwb/drp.c

   1 /*
   2  * Ultra Wide Band
   3  * Dynamic Reservation Protocol handling
   4  *
   5  * Copyright (C) 2005-2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7  * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License version
  11  * 2 as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21 #include <linux/kthread.h>
  22 #include <linux/freezer.h>
  23 #include <linux/slab.h>
  24 #include <linux/delay.h>
  25 #include "uwb-internal.h"
  26
  27
  28 /* DRP Conflict Actions ([ECMA-368 2nd Edition] 17.4.6) */
  29 enum uwb_drp_conflict_action {
  30         /* Reservation is maintained, no action needed */
  31         UWB_DRP_CONFLICT_MANTAIN = 0,
  32
  33         /* the device shall not transmit frames in conflicting MASs in
  34          * the following superframe. If the device is the reservation
  35          * target, it shall also set the Reason Code in its DRP IE to
  36          * Conflict in its beacon in the following superframe.
  37          */
  38         UWB_DRP_CONFLICT_ACT1,
  39
  40         /* the device shall not set the Reservation Status bit to ONE
  41          * and shall not transmit frames in conflicting MASs. If the
  42          * device is the reservation target, it shall also set the
  43          * Reason Code in its DRP IE to Conflict.
  44          */
  45         UWB_DRP_CONFLICT_ACT2,
  46
  47         /* the device shall not transmit frames in conflicting MASs in
  48          * the following superframe. It shall remove the conflicting
  49          * MASs from the reservation or set the Reservation Status to
  50          * ZERO in its beacon in the following superframe. If the
  51          * device is the reservation target, it shall also set the
  52          * Reason Code in its DRP IE to Conflict.
  53          */
  54         UWB_DRP_CONFLICT_ACT3,
  55 };
  56
  57
  58 static void uwb_rc_set_drp_cmd_done(struct uwb_rc *rc, void *arg,
  59                                     struct uwb_rceb *reply, ssize_t reply_size)
  60 {
  61         struct uwb_rc_evt_set_drp_ie *r = (struct uwb_rc_evt_set_drp_ie *)reply;
  62         unsigned long flags;
  63
  64         if (r != NULL) {
  65                 if (r->bResultCode != UWB_RC_RES_SUCCESS)
  66                         dev_err(&rc->uwb_dev.dev, "SET-DRP-IE failed: %s (%d)\n",
  67                                 uwb_rc_strerror(r->bResultCode), r->bResultCode);
  68         } else
  69                 dev_err(&rc->uwb_dev.dev, "SET-DRP-IE: timeout\n");
  70
  71         spin_lock_irqsave(&rc->rsvs_lock, flags);
  72         if (rc->set_drp_ie_pending > 1) {
  73                 rc->set_drp_ie_pending = 0;
  74                 uwb_rsv_queue_update(rc);
  75         } else {
  76                 rc->set_drp_ie_pending = 0;
  77         }
  78         spin_unlock_irqrestore(&rc->rsvs_lock, flags);
  79 }
  80
  81 /**
  82  * Construct and send the SET DRP IE
  83  *
  84  * @rc:         UWB Host controller
  85  * @returns:    >= 0 number of bytes still available in the beacon
  86  *              < 0 errno code on error.
  87  *
  88  * See WUSB[8.6.2.7]: The host must set all the DRP IEs that it wants the
  89  * device to include in its beacon at the same time. We thus have to
  90  * traverse all reservations and include the DRP IEs of all PENDING
  91  * and NEGOTIATED reservations in a SET DRP command for transmission.
  92  *
  93  * A DRP Availability IE is appended.
  94  *
  95  * rc->rsvs_mutex is held
  96  *
  97  * FIXME We currently ignore the returned value indicating the remaining space
  98  * in beacon. This could be used to deny reservation requests earlier if
  99  * determined that they would cause the beacon space to be exceeded.
 100  */
 101 int uwb_rc_send_all_drp_ie(struct uwb_rc *rc)
 102 {
 103         int result;
 104         struct uwb_rc_cmd_set_drp_ie *cmd;
 105         struct uwb_rsv *rsv;
 106         struct uwb_rsv_move *mv;
 107         int num_bytes = 0;
 108         u8 *IEDataptr;
 109
 110         result = -ENOMEM;
 111         /* First traverse all reservations to determine memory needed. */
 112         list_for_each_entry(rsv, &rc->reservations, rc_node) {
 113                 if (rsv->drp_ie != NULL) {
 114                         num_bytes += rsv->drp_ie->hdr.length + 2;
 115                         if (uwb_rsv_has_two_drp_ies(rsv) &&
 116                                 (rsv->mv.companion_drp_ie != NULL)) {
 117                                 mv = &rsv->mv;
 118                                 num_bytes +=
 119                                         mv->companion_drp_ie->hdr.length + 2;
 120                         }
 121                 }
 122         }
 123         num_bytes += sizeof(rc->drp_avail.ie);
 124         cmd = kzalloc(sizeof(*cmd) + num_bytes, GFP_KERNEL);
 125         if (cmd == NULL)
 126                 goto error;
 127         cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
 128         cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_DRP_IE);
 129         cmd->wIELength = num_bytes;
 130         IEDataptr = (u8 *)&cmd->IEData[0];
 131
 132         /* FIXME: DRV avail IE is not always needed */
 133         /* put DRP avail IE first */
 134         memcpy(IEDataptr, &rc->drp_avail.ie, sizeof(rc->drp_avail.ie));
 135         IEDataptr += sizeof(struct uwb_ie_drp_avail);
 136
 137         /* Next traverse all reservations to place IEs in allocated memory. */
 138         list_for_each_entry(rsv, &rc->reservations, rc_node) {
 139                 if (rsv->drp_ie != NULL) {
 140                         memcpy(IEDataptr, rsv->drp_ie,
 141                                rsv->drp_ie->hdr.length + 2);
 142                         IEDataptr += rsv->drp_ie->hdr.length + 2;
 143
 144                         if (uwb_rsv_has_two_drp_ies(rsv) &&
 145                                 (rsv->mv.companion_drp_ie != NULL)) {
 146                                 mv = &rsv->mv;
 147                                 memcpy(IEDataptr, mv->companion_drp_ie,
 148                                        mv->companion_drp_ie->hdr.length + 2);
 149                                 IEDataptr +=
 150                                         mv->companion_drp_ie->hdr.length + 2;
 151                         }
 152                 }
 153         }
 154
 155         result = uwb_rc_cmd_async(rc, "SET-DRP-IE",
 156                                 &cmd->rccb, sizeof(*cmd) + num_bytes,
 157                                 UWB_RC_CET_GENERAL, UWB_RC_CMD_SET_DRP_IE,
 158                                 uwb_rc_set_drp_cmd_done, NULL);
 159
 160         rc->set_drp_ie_pending = 1;
 161
 162         kfree(cmd);
 163 error:
 164         return result;
 165 }
 166
 167 /*
 168  * Evaluate the action to perform using conflict resolution rules
 169  *
 170  * Return a uwb_drp_conflict_action.
 171  */
 172 static int evaluate_conflict_action(struct uwb_ie_drp *ext_drp_ie, int ext_beacon_slot,
 173                                     struct uwb_rsv *rsv, int our_status)
 174 {
 175         int our_tie_breaker = rsv->tiebreaker;
 176         int our_type        = rsv->type;
 177         int our_beacon_slot = rsv->rc->uwb_dev.beacon_slot;
 178
 179         int ext_tie_breaker = uwb_ie_drp_tiebreaker(ext_drp_ie);
 180         int ext_status      = uwb_ie_drp_status(ext_drp_ie);
 181         int ext_type        = uwb_ie_drp_type(ext_drp_ie);
 182
 183
 184         /* [ECMA-368 2nd Edition] 17.4.6 */
 185         if (ext_type == UWB_DRP_TYPE_PCA && our_type == UWB_DRP_TYPE_PCA) {
 186                 return UWB_DRP_CONFLICT_MANTAIN;
 187         }
 188
 189         /* [ECMA-368 2nd Edition] 17.4.6-1 */
 190         if (our_type == UWB_DRP_TYPE_ALIEN_BP) {
 191                 return UWB_DRP_CONFLICT_MANTAIN;
 192         }
 193
 194         /* [ECMA-368 2nd Edition] 17.4.6-2 */
 195         if (ext_type == UWB_DRP_TYPE_ALIEN_BP) {
 196                 /* here we know our_type != UWB_DRP_TYPE_ALIEN_BP */
 197                 return UWB_DRP_CONFLICT_ACT1;
 198         }
 199
 200         /* [ECMA-368 2nd Edition] 17.4.6-3 */
 201         if (our_status == 0 && ext_status == 1) {
 202                 return UWB_DRP_CONFLICT_ACT2;
 203         }
 204
 205         /* [ECMA-368 2nd Edition] 17.4.6-4 */
 206         if (our_status == 1 && ext_status == 0) {
 207                 return UWB_DRP_CONFLICT_MANTAIN;
 208         }
 209
 210         /* [ECMA-368 2nd Edition] 17.4.6-5a */
 211         if (our_tie_breaker == ext_tie_breaker &&
 212             our_beacon_slot <  ext_beacon_slot) {
 213                 return UWB_DRP_CONFLICT_MANTAIN;
 214         }
 215
 216         /* [ECMA-368 2nd Edition] 17.4.6-5b */
 217         if (our_tie_breaker != ext_tie_breaker &&
 218             our_beacon_slot >  ext_beacon_slot) {
 219                 return UWB_DRP_CONFLICT_MANTAIN;
 220         }
 221
 222         if (our_status == 0) {
 223                 if (our_tie_breaker == ext_tie_breaker) {
 224                         /* [ECMA-368 2nd Edition] 17.4.6-6a */
 225                         if (our_beacon_slot > ext_beacon_slot) {
 226                                 return UWB_DRP_CONFLICT_ACT2;
 227                         }
 228                 } else  {
 229                         /* [ECMA-368 2nd Edition] 17.4.6-6b */
 230                         if (our_beacon_slot < ext_beacon_slot) {
 231                                 return UWB_DRP_CONFLICT_ACT2;
 232                         }
 233                 }
 234         } else {
 235                 if (our_tie_breaker == ext_tie_breaker) {
 236                         /* [ECMA-368 2nd Edition] 17.4.6-7a */
 237                         if (our_beacon_slot > ext_beacon_slot) {
 238                                 return UWB_DRP_CONFLICT_ACT3;
 239                         }
 240                 } else {
 241                         /* [ECMA-368 2nd Edition] 17.4.6-7b */
 242                         if (our_beacon_slot < ext_beacon_slot) {
 243                                 return UWB_DRP_CONFLICT_ACT3;
 244                         }
 245                 }
 246         }
 247         return UWB_DRP_CONFLICT_MANTAIN;
 248 }
 249
 250 static void handle_conflict_normal(struct uwb_ie_drp *drp_ie,
 251                                    int ext_beacon_slot,
 252                                    struct uwb_rsv *rsv,
 253                                    struct uwb_mas_bm *conflicting_mas)
 254 {
 255         struct uwb_rc *rc = rsv->rc;
 256         struct uwb_rsv_move *mv = &rsv->mv;
 257         struct uwb_drp_backoff_win *bow = &rc->bow;
 258         int action;
 259
 260         action = evaluate_conflict_action(drp_ie, ext_beacon_slot, rsv, uwb_rsv_status(rsv));
 261
 262         if (uwb_rsv_is_owner(rsv)) {
 263                 switch(action) {
 264                 case UWB_DRP_CONFLICT_ACT2:
 265                         /* try move */
 266                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_TO_BE_MOVED);
 267                         if (bow->can_reserve_extra_mases == false)
 268                                 uwb_rsv_backoff_win_increment(rc);
 269
 270                         break;
 271                 case UWB_DRP_CONFLICT_ACT3:
 272                         uwb_rsv_backoff_win_increment(rc);
 273                         /* drop some mases with reason modified */
 274                         /* put in the companion the mases to be dropped */
 275                         bitmap_and(mv->companion_mas.bm, rsv->mas.bm, conflicting_mas->bm, UWB_NUM_MAS);
 276                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MODIFIED);
 277                 default:
 278                         break;
 279                 }
 280         } else {
 281                 switch(action) {
 282                 case UWB_DRP_CONFLICT_ACT2:
 283                 case UWB_DRP_CONFLICT_ACT3:
 284                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_CONFLICT);
 285                 default:
 286                         break;
 287                 }
 288
 289         }
 290
 291 }
 292
 293 static void handle_conflict_expanding(struct uwb_ie_drp *drp_ie, int ext_beacon_slot,
 294                                       struct uwb_rsv *rsv, bool companion_only,
 295                                       struct uwb_mas_bm *conflicting_mas)
 296 {
 297         struct uwb_rc *rc = rsv->rc;
 298         struct uwb_drp_backoff_win *bow = &rc->bow;
 299         struct uwb_rsv_move *mv = &rsv->mv;
 300         int action;
 301
 302         if (companion_only) {
 303                 /* status of companion is 0 at this point */
 304                 action = evaluate_conflict_action(drp_ie, ext_beacon_slot, rsv, 0);
 305                 if (uwb_rsv_is_owner(rsv)) {
 306                         switch(action) {
 307                         case UWB_DRP_CONFLICT_ACT2:
 308                         case UWB_DRP_CONFLICT_ACT3:
 309                                 uwb_rsv_set_state(rsv,
 310                                                 UWB_RSV_STATE_O_ESTABLISHED);
 311                                 rsv->needs_release_companion_mas = false;
 312                                 if (bow->can_reserve_extra_mases == false)
 313                                         uwb_rsv_backoff_win_increment(rc);
 314                                 uwb_drp_avail_release(rsv->rc,
 315                                                 &rsv->mv.companion_mas);
 316                         }
 317                 } else { /* rsv is target */
 318                         switch(action) {
 319                         case UWB_DRP_CONFLICT_ACT2:
 320                         case UWB_DRP_CONFLICT_ACT3:
 321                                 uwb_rsv_set_state(rsv,
 322                                         UWB_RSV_STATE_T_EXPANDING_CONFLICT);
 323                                 /* send_drp_avail_ie = true; */
 324                         }
 325                 }
 326         } else { /* also base part of the reservation is conflicting */
 327                 if (uwb_rsv_is_owner(rsv)) {
 328                         uwb_rsv_backoff_win_increment(rc);
 329                         /* remove companion part */
 330                         uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
 331
 332                         /* drop some mases with reason modified */
 333
 334                         /* put in the companion the mases to be dropped */
 335                         bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm,
 336                                         conflicting_mas->bm, UWB_NUM_MAS);
 337                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MODIFIED);
 338                 } else { /* it is a target rsv */
 339                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_CONFLICT);
 340                         /* send_drp_avail_ie = true; */
 341                 }
 342         }
 343 }
 344
 345 static void uwb_drp_handle_conflict_rsv(struct uwb_rc *rc, struct uwb_rsv *rsv,
 346                                         struct uwb_rc_evt_drp *drp_evt,
 347                                         struct uwb_ie_drp *drp_ie,
 348                                         struct uwb_mas_bm *conflicting_mas)
 349 {
 350         struct uwb_rsv_move *mv;
 351
 352         /* check if the conflicting reservation has two drp_ies */
 353         if (uwb_rsv_has_two_drp_ies(rsv)) {
 354                 mv = &rsv->mv;
 355                 if (bitmap_intersects(rsv->mas.bm, conflicting_mas->bm,
 356                                                                 UWB_NUM_MAS)) {
 357                         handle_conflict_expanding(drp_ie,
 358                                                 drp_evt->beacon_slot_number,
 359                                                 rsv, false, conflicting_mas);
 360                 } else {
 361                         if (bitmap_intersects(mv->companion_mas.bm,
 362                                         conflicting_mas->bm, UWB_NUM_MAS)) {
 363                                 handle_conflict_expanding(
 364                                         drp_ie, drp_evt->beacon_slot_number,
 365                                         rsv, true, conflicting_mas);
 366                         }
 367                 }
 368         } else if (bitmap_intersects(rsv->mas.bm, conflicting_mas->bm,
 369                                                         UWB_NUM_MAS)) {
 370                 handle_conflict_normal(drp_ie, drp_evt->beacon_slot_number,
 371                                         rsv, conflicting_mas);
 372         }
 373 }
 374
 375 static void uwb_drp_handle_all_conflict_rsv(struct uwb_rc *rc,
 376                                             struct uwb_rc_evt_drp *drp_evt,
 377                                             struct uwb_ie_drp *drp_ie,
 378                                             struct uwb_mas_bm *conflicting_mas)
 379 {
 380         struct uwb_rsv *rsv;
 381
 382         list_for_each_entry(rsv, &rc->reservations, rc_node) {
 383                 uwb_drp_handle_conflict_rsv(rc, rsv, drp_evt, drp_ie,
 384                                                         conflicting_mas);
 385         }
 386 }
 387
 388 static void uwb_drp_process_target_accepted(struct uwb_rc *rc,
 389         struct uwb_rsv *rsv, struct uwb_rc_evt_drp *drp_evt,
 390         struct uwb_ie_drp *drp_ie, struct uwb_mas_bm *mas)
 391 {
 392         struct uwb_rsv_move *mv = &rsv->mv;
 393         int status;
 394
 395         status = uwb_ie_drp_status(drp_ie);
 396
 397         if (rsv->state == UWB_RSV_STATE_T_CONFLICT) {
 398                 uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_CONFLICT);
 399                 return;
 400         }
 401
 402         if (rsv->state == UWB_RSV_STATE_T_EXPANDING_ACCEPTED) {
 403                 /* drp_ie is companion */
 404                 if (!bitmap_equal(rsv->mas.bm, mas->bm, UWB_NUM_MAS)) {
 405                         /* stroke companion */
 406                         uwb_rsv_set_state(rsv,
 407                                 UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
 408                 }
 409         } else {
 410                 if (!bitmap_equal(rsv->mas.bm, mas->bm, UWB_NUM_MAS)) {
 411                         if (uwb_drp_avail_reserve_pending(rc, mas) == -EBUSY) {
 412                                 /* FIXME: there is a conflict, find
 413                                  * the conflicting reservations and
 414                                  * take a sensible action. Consider
 415                                  * that in drp_ie there is the
 416                                  * "neighbour" */
 417                                 uwb_drp_handle_all_conflict_rsv(rc, drp_evt,
 418                                                 drp_ie, mas);
 419                         } else {
 420                                 /* accept the extra reservation */
 421                                 bitmap_copy(mv->companion_mas.bm, mas->bm,
 422                                                                 UWB_NUM_MAS);
 423                                 uwb_rsv_set_state(rsv,
 424                                         UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
 425                         }
 426                 } else {
 427                         if (status) {
 428                                 uwb_rsv_set_state(rsv,
 429                                                 UWB_RSV_STATE_T_ACCEPTED);
 430                         }
 431                 }
 432
 433         }
 434 }
 435
 436 /*
 437  * Based on the DRP IE, transition a target reservation to a new
 438  * state.
 439  */
 440 static void uwb_drp_process_target(struct uwb_rc *rc, struct uwb_rsv *rsv,
 441                    struct uwb_ie_drp *drp_ie, struct uwb_rc_evt_drp *drp_evt)
 442 {
 443         struct device *dev = &rc->uwb_dev.dev;
 444         struct uwb_rsv_move *mv = &rsv->mv;
 445         int status;
 446         enum uwb_drp_reason reason_code;
 447         struct uwb_mas_bm mas;
 448
 449         status = uwb_ie_drp_status(drp_ie);
 450         reason_code = uwb_ie_drp_reason_code(drp_ie);
 451         uwb_drp_ie_to_bm(&mas, drp_ie);
 452
 453         switch (reason_code) {
 454         case UWB_DRP_REASON_ACCEPTED:
 455                 uwb_drp_process_target_accepted(rc, rsv, drp_evt, drp_ie, &mas);
 456                 break;
 457
 458         case UWB_DRP_REASON_MODIFIED:
 459                 /* check to see if we have already modified the reservation */
 460                 if (bitmap_equal(rsv->mas.bm, mas.bm, UWB_NUM_MAS)) {
 461                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
 462                         break;
 463                 }
 464
 465                 /* find if the owner wants to expand or reduce */
 466                 if (bitmap_subset(mas.bm, rsv->mas.bm, UWB_NUM_MAS)) {
 467                         /* owner is reducing */
 468                         bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, mas.bm,
 469                                 UWB_NUM_MAS);
 470                         uwb_drp_avail_release(rsv->rc, &mv->companion_mas);
 471                 }
 472
 473                 bitmap_copy(rsv->mas.bm, mas.bm, UWB_NUM_MAS);
 474                 uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_RESIZED);
 475                 break;
 476         default:
 477                 dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
 478                          reason_code, status);
 479         }
 480 }
 481
 482 static void uwb_drp_process_owner_accepted(struct uwb_rsv *rsv,
 483                                                 struct uwb_mas_bm *mas)
 484 {
 485         struct uwb_rsv_move *mv = &rsv->mv;
 486
 487         switch (rsv->state) {
 488         case UWB_RSV_STATE_O_PENDING:
 489         case UWB_RSV_STATE_O_INITIATED:
 490         case UWB_RSV_STATE_O_ESTABLISHED:
 491                 uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
 492                 break;
 493         case UWB_RSV_STATE_O_MODIFIED:
 494                 if (bitmap_equal(mas->bm, rsv->mas.bm, UWB_NUM_MAS))
 495                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
 496                 else
 497                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MODIFIED);
 498                 break;
 499
 500         case UWB_RSV_STATE_O_MOVE_REDUCING: /* shouldn' t be a problem */
 501                 if (bitmap_equal(mas->bm, rsv->mas.bm, UWB_NUM_MAS))
 502                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
 503                 else
 504                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
 505                 break;
 506         case UWB_RSV_STATE_O_MOVE_EXPANDING:
 507                 if (bitmap_equal(mas->bm, mv->companion_mas.bm, UWB_NUM_MAS)) {
 508                         /* Companion reservation accepted */
 509                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
 510                 } else {
 511                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
 512                 }
 513                 break;
 514         case UWB_RSV_STATE_O_MOVE_COMBINING:
 515                 if (bitmap_equal(mas->bm, rsv->mas.bm, UWB_NUM_MAS))
 516                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
 517                 else
 518                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
 519                 break;
 520         default:
 521                 break;
 522         }
 523 }
 524 /*
 525  * Based on the DRP IE, transition an owner reservation to a new
 526  * state.
 527  */
 528 static void uwb_drp_process_owner(struct uwb_rc *rc, struct uwb_rsv *rsv,
 529                                   struct uwb_dev *src, struct uwb_ie_drp *drp_ie,
 530                                   struct uwb_rc_evt_drp *drp_evt)
 531 {
 532         struct device *dev = &rc->uwb_dev.dev;
 533         int status;
 534         enum uwb_drp_reason reason_code;
 535         struct uwb_mas_bm mas;
 536
 537         status = uwb_ie_drp_status(drp_ie);
 538         reason_code = uwb_ie_drp_reason_code(drp_ie);
 539         uwb_drp_ie_to_bm(&mas, drp_ie);
 540
 541         if (status) {
 542                 switch (reason_code) {
 543                 case UWB_DRP_REASON_ACCEPTED:
 544                         uwb_drp_process_owner_accepted(rsv, &mas);
 545                         break;
 546                 default:
 547                         dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
 548                                  reason_code, status);
 549                 }
 550         } else {
 551                 switch (reason_code) {
 552                 case UWB_DRP_REASON_PENDING:
 553                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_PENDING);
 554                         break;
 555                 case UWB_DRP_REASON_DENIED:
 556                         uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
 557                         break;
 558                 case UWB_DRP_REASON_CONFLICT:
 559                         /* resolve the conflict */
 560                         bitmap_complement(mas.bm, src->last_availability_bm,
 561                                           UWB_NUM_MAS);
 562                         uwb_drp_handle_conflict_rsv(rc, rsv, drp_evt, drp_ie, &mas);
 563                         break;
 564                 default:
 565                         dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
 566                                  reason_code, status);
 567                 }
 568         }
 569 }
 570
 571 static void uwb_cnflt_alien_stroke_timer(struct uwb_cnflt_alien *cnflt)
 572 {
 573         unsigned timeout_us = UWB_MAX_LOST_BEACONS * UWB_SUPERFRAME_LENGTH_US;
 574         mod_timer(&cnflt->timer, jiffies + usecs_to_jiffies(timeout_us));
 575 }
 576
 577 static void uwb_cnflt_update_work(struct work_struct *work)
 578 {
 579         struct uwb_cnflt_alien *cnflt = container_of(work,
 580                                                      struct uwb_cnflt_alien,
 581                                                      cnflt_update_work);
 582         struct uwb_cnflt_alien *c;
 583         struct uwb_rc *rc = cnflt->rc;
 584
 585         unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
 586
 587         mutex_lock(&rc->rsvs_mutex);
 588
 589         list_del(&cnflt->rc_node);
 590
 591         /* update rc global conflicting alien bitmap */
 592         bitmap_zero(rc->cnflt_alien_bitmap.bm, UWB_NUM_MAS);
 593
 594         list_for_each_entry(c, &rc->cnflt_alien_list, rc_node) {
 595                 bitmap_or(rc->cnflt_alien_bitmap.bm, rc->cnflt_alien_bitmap.bm,
 596                                                 c->mas.bm, UWB_NUM_MAS);
 597         }
 598
 599         queue_delayed_work(rc->rsv_workq, &rc->rsv_alien_bp_work,
 600                                         usecs_to_jiffies(delay_us));
 601
 602         kfree(cnflt);
 603         mutex_unlock(&rc->rsvs_mutex);
 604 }
 605
 606 static void uwb_cnflt_timer(struct timer_list *t)
 607 {
 608         struct uwb_cnflt_alien *cnflt = from_timer(cnflt, t, timer);
 609
 610         queue_work(cnflt->rc->rsv_workq, &cnflt->cnflt_update_work);
 611 }
 612
 613 /*
 614  * We have received an DRP_IE of type Alien BP and we need to make
 615  * sure we do not transmit in conflicting MASs.
 616  */
 617 static void uwb_drp_handle_alien_drp(struct uwb_rc *rc, struct uwb_ie_drp *drp_ie)
 618 {
 619         struct device *dev = &rc->uwb_dev.dev;
 620         struct uwb_mas_bm mas;
 621         struct uwb_cnflt_alien *cnflt;
 622         unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
 623
 624         uwb_drp_ie_to_bm(&mas, drp_ie);
 625
 626         list_for_each_entry(cnflt, &rc->cnflt_alien_list, rc_node) {
 627                 if (bitmap_equal(cnflt->mas.bm, mas.bm, UWB_NUM_MAS)) {
 628                         /* Existing alien BP reservation conflicting
 629                          * bitmap, just reset the timer */
 630                         uwb_cnflt_alien_stroke_timer(cnflt);
 631                         return;
 632                 }
 633         }
 634
 635         /* New alien BP reservation conflicting bitmap */
 636
 637         /* alloc and initialize new uwb_cnflt_alien */
 638         cnflt = kzalloc(sizeof(struct uwb_cnflt_alien), GFP_KERNEL);
 639         if (!cnflt) {
 640                 dev_err(dev, "failed to alloc uwb_cnflt_alien struct\n");
 641                 return;
 642         }
 643
 644         INIT_LIST_HEAD(&cnflt->rc_node);
 645         timer_setup(&cnflt->timer, uwb_cnflt_timer, 0);
 646
 647         cnflt->rc = rc;
 648         INIT_WORK(&cnflt->cnflt_update_work, uwb_cnflt_update_work);
 649
 650         bitmap_copy(cnflt->mas.bm, mas.bm, UWB_NUM_MAS);
 651
 652         list_add_tail(&cnflt->rc_node, &rc->cnflt_alien_list);
 653
 654         /* update rc global conflicting alien bitmap */
 655         bitmap_or(rc->cnflt_alien_bitmap.bm, rc->cnflt_alien_bitmap.bm, mas.bm, UWB_NUM_MAS);
 656
 657         queue_delayed_work(rc->rsv_workq, &rc->rsv_alien_bp_work, usecs_to_jiffies(delay_us));
 658
 659         /* start the timer */
 660         uwb_cnflt_alien_stroke_timer(cnflt);
 661 }
 662
 663 static void uwb_drp_process_not_involved(struct uwb_rc *rc,
 664                                          struct uwb_rc_evt_drp *drp_evt,
 665                                          struct uwb_ie_drp *drp_ie)
 666 {
 667         struct uwb_mas_bm mas;
 668
 669         uwb_drp_ie_to_bm(&mas, drp_ie);
 670         uwb_drp_handle_all_conflict_rsv(rc, drp_evt, drp_ie, &mas);
 671 }
 672
 673 static void uwb_drp_process_involved(struct uwb_rc *rc, struct uwb_dev *src,
 674                                      struct uwb_rc_evt_drp *drp_evt,
 675                                      struct uwb_ie_drp *drp_ie)
 676 {
 677         struct uwb_rsv *rsv;
 678
 679         rsv = uwb_rsv_find(rc, src, drp_ie);
 680         if (!rsv) {
 681                 /*
 682                  * No reservation? It's either for a recently
 683                  * terminated reservation; or the DRP IE couldn't be
 684                  * processed (e.g., an invalid IE or out of memory).
 685                  */
 686                 return;
 687         }
 688
 689         /*
 690          * Do nothing with DRP IEs for reservations that have been
 691          * terminated.
 692          */
 693         if (rsv->state == UWB_RSV_STATE_NONE) {
 694                 uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
 695                 return;
 696         }
 697
 698         if (uwb_ie_drp_owner(drp_ie))
 699                 uwb_drp_process_target(rc, rsv, drp_ie, drp_evt);
 700         else
 701                 uwb_drp_process_owner(rc, rsv, src, drp_ie, drp_evt);
 702
 703 }
 704
 705
 706 static bool uwb_drp_involves_us(struct uwb_rc *rc, struct uwb_ie_drp *drp_ie)
 707 {
 708         return uwb_dev_addr_cmp(&rc->uwb_dev.dev_addr, &drp_ie->dev_addr) == 0;
 709 }
 710
 711 /*
 712  * Process a received DRP IE.
 713  */
 714 static void uwb_drp_process(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt,
 715                             struct uwb_dev *src, struct uwb_ie_drp *drp_ie)
 716 {
 717         if (uwb_ie_drp_type(drp_ie) == UWB_DRP_TYPE_ALIEN_BP)
 718                 uwb_drp_handle_alien_drp(rc, drp_ie);
 719         else if (uwb_drp_involves_us(rc, drp_ie))
 720                 uwb_drp_process_involved(rc, src, drp_evt, drp_ie);
 721         else
 722                 uwb_drp_process_not_involved(rc, drp_evt, drp_ie);
 723 }
 724
 725 /*
 726  * Process a received DRP Availability IE
 727  */
 728 static void uwb_drp_availability_process(struct uwb_rc *rc, struct uwb_dev *src,
 729                                          struct uwb_ie_drp_avail *drp_availability_ie)
 730 {
 731         bitmap_copy(src->last_availability_bm,
 732                     drp_availability_ie->bmp, UWB_NUM_MAS);
 733 }
 734
 735 /*
 736  * Process all the DRP IEs (both DRP IEs and the DRP Availability IE)
 737  * from a device.
 738  */
 739 static
 740 void uwb_drp_process_all(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt,
 741                          size_t ielen, struct uwb_dev *src_dev)
 742 {
 743         struct device *dev = &rc->uwb_dev.dev;
 744         struct uwb_ie_hdr *ie_hdr;
 745         void *ptr;
 746
 747         ptr = drp_evt->ie_data;
 748         for (;;) {
 749                 ie_hdr = uwb_ie_next(&ptr, &ielen);
 750                 if (!ie_hdr)
 751                         break;
 752
 753                 switch (ie_hdr->element_id) {
 754                 case UWB_IE_DRP_AVAILABILITY:
 755                         uwb_drp_availability_process(rc, src_dev, (struct uwb_ie_drp_avail *)ie_hdr);
 756                         break;
 757                 case UWB_IE_DRP:
 758                         uwb_drp_process(rc, drp_evt, src_dev, (struct uwb_ie_drp *)ie_hdr);
 759                         break;
 760                 default:
 761                         dev_warn(dev, "unexpected IE in DRP notification\n");
 762                         break;
 763                 }
 764         }
 765
 766         if (ielen > 0)
 767                 dev_warn(dev, "%d octets remaining in DRP notification\n",
 768                          (int)ielen);
 769 }
 770
 771 /**
 772  * uwbd_evt_handle_rc_drp - handle a DRP_IE event
 773  * @evt: the DRP_IE event from the radio controller
 774  *
 775  * This processes DRP notifications from the radio controller, either
 776  * initiating a new reservation or transitioning an existing
 777  * reservation into a different state.
 778  *
 779  * DRP notifications can occur for three different reasons:
 780  *
 781  * - UWB_DRP_NOTIF_DRP_IE_RECVD: one or more DRP IEs with the RC as
 782  *   the target or source have been received.
 783  *
 784  *   These DRP IEs could be new or for an existing reservation.
 785  *
 786  *   If the DRP IE for an existing reservation ceases to be to
 787  *   received for at least mMaxLostBeacons, the reservation should be
 788  *   considered to be terminated.  Note that the TERMINATE reason (see
 789  *   below) may not always be signalled (e.g., the remote device has
 790  *   two or more reservations established with the RC).
 791  *
 792  * - UWB_DRP_NOTIF_CONFLICT: DRP IEs from any device in the beacon
 793  *   group conflict with the RC's reservations.
 794  *
 795  * - UWB_DRP_NOTIF_TERMINATE: DRP IEs are no longer being received
 796  *   from a device (i.e., it's terminated all reservations).
 797  *
 798  * Only the software state of the reservations is changed; the setting
 799  * of the radio controller's DRP IEs is done after all the events in
 800  * an event buffer are processed.  This saves waiting multiple times
 801  * for the SET_DRP_IE command to complete.
 802  */
 803 int uwbd_evt_handle_rc_drp(struct uwb_event *evt)
 804 {
 805         struct device *dev = &evt->rc->uwb_dev.dev;
 806         struct uwb_rc *rc = evt->rc;
 807         struct uwb_rc_evt_drp *drp_evt;
 808         size_t ielength, bytes_left;
 809         struct uwb_dev_addr src_addr;
 810         struct uwb_dev *src_dev;
 811
 812         /* Is there enough data to decode the event (and any IEs in
 813            its payload)? */
 814         if (evt->notif.size < sizeof(*drp_evt)) {
 815                 dev_err(dev, "DRP event: Not enough data to decode event "
 816                         "[%zu bytes left, %zu needed]\n",
 817                         evt->notif.size, sizeof(*drp_evt));
 818                 return 0;
 819         }
 820         bytes_left = evt->notif.size - sizeof(*drp_evt);
 821         drp_evt = container_of(evt->notif.rceb, struct uwb_rc_evt_drp, rceb);
 822         ielength = le16_to_cpu(drp_evt->ie_length);
 823         if (bytes_left != ielength) {
 824                 dev_err(dev, "DRP event: Not enough data in payload [%zu"
 825                         "bytes left, %zu declared in the event]\n",
 826                         bytes_left, ielength);
 827                 return 0;
 828         }
 829
 830         memcpy(src_addr.data, &drp_evt->src_addr, sizeof(src_addr));
 831         src_dev = uwb_dev_get_by_devaddr(rc, &src_addr);
 832         if (!src_dev) {
 833                 /*
 834                  * A DRP notification from an unrecognized device.
 835                  *
 836                  * This is probably from a WUSB device that doesn't
 837                  * have an EUI-48 and therefore doesn't show up in the
 838                  * UWB device database.  It's safe to simply ignore
 839                  * these.
 840                  */
 841                 return 0;
 842         }
 843
 844         mutex_lock(&rc->rsvs_mutex);
 845
 846         /* We do not distinguish from the reason */
 847         uwb_drp_process_all(rc, drp_evt, ielength, src_dev);
 848
 849         mutex_unlock(&rc->rsvs_mutex);
 850
 851         uwb_dev_put(src_dev);
 852         return 0;
 853 }