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