v4.19.13 snapshot.
diff --git a/drivers/uwb/drp.c b/drivers/uwb/drp.c
new file mode 100644
index 0000000..625f706
--- /dev/null
+++ b/drivers/uwb/drp.c
@@ -0,0 +1,853 @@
+/*
+ * Ultra Wide Band
+ * Dynamic Reservation Protocol handling
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/kthread.h>
+#include <linux/freezer.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include "uwb-internal.h"
+
+
+/* DRP Conflict Actions ([ECMA-368 2nd Edition] 17.4.6) */
+enum uwb_drp_conflict_action {
+	/* Reservation is maintained, no action needed */
+	UWB_DRP_CONFLICT_MANTAIN = 0,
+
+	/* the device shall not transmit frames in conflicting MASs in
+	 * the following superframe. If the device is the reservation
+	 * target, it shall also set the Reason Code in its DRP IE to
+	 * Conflict in its beacon in the following superframe.
+	 */
+	UWB_DRP_CONFLICT_ACT1,
+
+	/* the device shall not set the Reservation Status bit to ONE
+	 * and shall not transmit frames in conflicting MASs. If the
+	 * device is the reservation target, it shall also set the
+	 * Reason Code in its DRP IE to Conflict.
+	 */
+	UWB_DRP_CONFLICT_ACT2,
+
+	/* the device shall not transmit frames in conflicting MASs in
+	 * the following superframe. It shall remove the conflicting
+	 * MASs from the reservation or set the Reservation Status to
+	 * ZERO in its beacon in the following superframe. If the
+	 * device is the reservation target, it shall also set the
+	 * Reason Code in its DRP IE to Conflict.
+	 */
+	UWB_DRP_CONFLICT_ACT3,
+};
+
+
+static void uwb_rc_set_drp_cmd_done(struct uwb_rc *rc, void *arg,
+				    struct uwb_rceb *reply, ssize_t reply_size)
+{
+	struct uwb_rc_evt_set_drp_ie *r = (struct uwb_rc_evt_set_drp_ie *)reply;
+	unsigned long flags;
+
+	if (r != NULL) {
+		if (r->bResultCode != UWB_RC_RES_SUCCESS)
+			dev_err(&rc->uwb_dev.dev, "SET-DRP-IE failed: %s (%d)\n",
+				uwb_rc_strerror(r->bResultCode), r->bResultCode);
+	} else
+		dev_err(&rc->uwb_dev.dev, "SET-DRP-IE: timeout\n");
+
+	spin_lock_irqsave(&rc->rsvs_lock, flags);
+	if (rc->set_drp_ie_pending > 1) {
+		rc->set_drp_ie_pending = 0;
+		uwb_rsv_queue_update(rc);
+	} else {
+		rc->set_drp_ie_pending = 0;
+	}
+	spin_unlock_irqrestore(&rc->rsvs_lock, flags);
+}
+
+/**
+ * Construct and send the SET DRP IE
+ *
+ * @rc:         UWB Host controller
+ * @returns:    >= 0 number of bytes still available in the beacon
+ *              < 0 errno code on error.
+ *
+ * See WUSB[8.6.2.7]: The host must set all the DRP IEs that it wants the
+ * device to include in its beacon at the same time. We thus have to
+ * traverse all reservations and include the DRP IEs of all PENDING
+ * and NEGOTIATED reservations in a SET DRP command for transmission.
+ *
+ * A DRP Availability IE is appended.
+ *
+ * rc->rsvs_mutex is held
+ *
+ * FIXME We currently ignore the returned value indicating the remaining space
+ * in beacon. This could be used to deny reservation requests earlier if
+ * determined that they would cause the beacon space to be exceeded.
+ */
+int uwb_rc_send_all_drp_ie(struct uwb_rc *rc)
+{
+	int result;
+	struct uwb_rc_cmd_set_drp_ie *cmd;
+	struct uwb_rsv *rsv;
+	struct uwb_rsv_move *mv;
+	int num_bytes = 0;
+	u8 *IEDataptr;
+
+	result = -ENOMEM;
+	/* First traverse all reservations to determine memory needed. */
+	list_for_each_entry(rsv, &rc->reservations, rc_node) {
+		if (rsv->drp_ie != NULL) {
+			num_bytes += rsv->drp_ie->hdr.length + 2;
+			if (uwb_rsv_has_two_drp_ies(rsv) &&
+				(rsv->mv.companion_drp_ie != NULL)) {
+				mv = &rsv->mv;
+				num_bytes +=
+					mv->companion_drp_ie->hdr.length + 2;
+			}
+		}
+	}
+	num_bytes += sizeof(rc->drp_avail.ie);
+	cmd = kzalloc(sizeof(*cmd) + num_bytes, GFP_KERNEL);
+	if (cmd == NULL)
+		goto error;
+	cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
+	cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_DRP_IE);
+	cmd->wIELength = num_bytes;
+	IEDataptr = (u8 *)&cmd->IEData[0];
+
+	/* FIXME: DRV avail IE is not always needed */
+	/* put DRP avail IE first */
+	memcpy(IEDataptr, &rc->drp_avail.ie, sizeof(rc->drp_avail.ie));
+	IEDataptr += sizeof(struct uwb_ie_drp_avail);
+
+	/* Next traverse all reservations to place IEs in allocated memory. */
+	list_for_each_entry(rsv, &rc->reservations, rc_node) {
+		if (rsv->drp_ie != NULL) {
+			memcpy(IEDataptr, rsv->drp_ie,
+			       rsv->drp_ie->hdr.length + 2);
+			IEDataptr += rsv->drp_ie->hdr.length + 2;
+
+			if (uwb_rsv_has_two_drp_ies(rsv) &&
+				(rsv->mv.companion_drp_ie != NULL)) {
+				mv = &rsv->mv;
+				memcpy(IEDataptr, mv->companion_drp_ie,
+				       mv->companion_drp_ie->hdr.length + 2);
+				IEDataptr +=
+					mv->companion_drp_ie->hdr.length + 2;
+			}
+		}
+	}
+
+	result = uwb_rc_cmd_async(rc, "SET-DRP-IE",
+				&cmd->rccb, sizeof(*cmd) + num_bytes,
+				UWB_RC_CET_GENERAL, UWB_RC_CMD_SET_DRP_IE,
+				uwb_rc_set_drp_cmd_done, NULL);
+
+	rc->set_drp_ie_pending = 1;
+
+	kfree(cmd);
+error:
+	return result;
+}
+
+/*
+ * Evaluate the action to perform using conflict resolution rules
+ *
+ * Return a uwb_drp_conflict_action.
+ */
+static int evaluate_conflict_action(struct uwb_ie_drp *ext_drp_ie, int ext_beacon_slot,
+				    struct uwb_rsv *rsv, int our_status)
+{
+	int our_tie_breaker = rsv->tiebreaker;
+	int our_type        = rsv->type;
+	int our_beacon_slot = rsv->rc->uwb_dev.beacon_slot;
+
+	int ext_tie_breaker = uwb_ie_drp_tiebreaker(ext_drp_ie);
+	int ext_status      = uwb_ie_drp_status(ext_drp_ie);
+	int ext_type        = uwb_ie_drp_type(ext_drp_ie);
+
+
+	/* [ECMA-368 2nd Edition] 17.4.6 */
+	if (ext_type == UWB_DRP_TYPE_PCA && our_type == UWB_DRP_TYPE_PCA) {
+		return UWB_DRP_CONFLICT_MANTAIN;
+	}
+
+	/* [ECMA-368 2nd Edition] 17.4.6-1 */
+	if (our_type == UWB_DRP_TYPE_ALIEN_BP) {
+		return UWB_DRP_CONFLICT_MANTAIN;
+	}
+
+	/* [ECMA-368 2nd Edition] 17.4.6-2 */
+	if (ext_type == UWB_DRP_TYPE_ALIEN_BP) {
+		/* here we know our_type != UWB_DRP_TYPE_ALIEN_BP */
+		return UWB_DRP_CONFLICT_ACT1;
+	}
+
+	/* [ECMA-368 2nd Edition] 17.4.6-3 */
+	if (our_status == 0 && ext_status == 1) {
+		return UWB_DRP_CONFLICT_ACT2;
+	}
+
+	/* [ECMA-368 2nd Edition] 17.4.6-4 */
+	if (our_status == 1 && ext_status == 0) {
+		return UWB_DRP_CONFLICT_MANTAIN;
+	}
+
+	/* [ECMA-368 2nd Edition] 17.4.6-5a */
+	if (our_tie_breaker == ext_tie_breaker &&
+	    our_beacon_slot <  ext_beacon_slot) {
+		return UWB_DRP_CONFLICT_MANTAIN;
+	}
+
+	/* [ECMA-368 2nd Edition] 17.4.6-5b */
+	if (our_tie_breaker != ext_tie_breaker &&
+	    our_beacon_slot >  ext_beacon_slot) {
+		return UWB_DRP_CONFLICT_MANTAIN;
+	}
+
+	if (our_status == 0) {
+		if (our_tie_breaker == ext_tie_breaker) {
+			/* [ECMA-368 2nd Edition] 17.4.6-6a */
+			if (our_beacon_slot > ext_beacon_slot) {
+				return UWB_DRP_CONFLICT_ACT2;
+			}
+		} else  {
+			/* [ECMA-368 2nd Edition] 17.4.6-6b */
+			if (our_beacon_slot < ext_beacon_slot) {
+				return UWB_DRP_CONFLICT_ACT2;
+			}
+		}
+	} else {
+		if (our_tie_breaker == ext_tie_breaker) {
+			/* [ECMA-368 2nd Edition] 17.4.6-7a */
+			if (our_beacon_slot > ext_beacon_slot) {
+				return UWB_DRP_CONFLICT_ACT3;
+			}
+		} else {
+			/* [ECMA-368 2nd Edition] 17.4.6-7b */
+			if (our_beacon_slot < ext_beacon_slot) {
+				return UWB_DRP_CONFLICT_ACT3;
+			}
+		}
+	}
+	return UWB_DRP_CONFLICT_MANTAIN;
+}
+
+static void handle_conflict_normal(struct uwb_ie_drp *drp_ie,
+				   int ext_beacon_slot,
+				   struct uwb_rsv *rsv,
+				   struct uwb_mas_bm *conflicting_mas)
+{
+	struct uwb_rc *rc = rsv->rc;
+	struct uwb_rsv_move *mv = &rsv->mv;
+	struct uwb_drp_backoff_win *bow = &rc->bow;
+	int action;
+
+	action = evaluate_conflict_action(drp_ie, ext_beacon_slot, rsv, uwb_rsv_status(rsv));
+
+	if (uwb_rsv_is_owner(rsv)) {
+		switch(action) {
+		case UWB_DRP_CONFLICT_ACT2:
+			/* try move */
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_TO_BE_MOVED);
+			if (bow->can_reserve_extra_mases == false)
+				uwb_rsv_backoff_win_increment(rc);
+
+			break;
+		case UWB_DRP_CONFLICT_ACT3:
+			uwb_rsv_backoff_win_increment(rc);
+			/* drop some mases with reason modified */
+			/* put in the companion the mases to be dropped */
+			bitmap_and(mv->companion_mas.bm, rsv->mas.bm, conflicting_mas->bm, UWB_NUM_MAS);
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MODIFIED);
+		default:
+			break;
+		}
+	} else {
+		switch(action) {
+		case UWB_DRP_CONFLICT_ACT2:
+		case UWB_DRP_CONFLICT_ACT3:
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_CONFLICT);
+		default:
+			break;
+		}
+
+	}
+
+}
+
+static void handle_conflict_expanding(struct uwb_ie_drp *drp_ie, int ext_beacon_slot,
+				      struct uwb_rsv *rsv, bool companion_only,
+				      struct uwb_mas_bm *conflicting_mas)
+{
+	struct uwb_rc *rc = rsv->rc;
+	struct uwb_drp_backoff_win *bow = &rc->bow;
+	struct uwb_rsv_move *mv = &rsv->mv;
+	int action;
+
+	if (companion_only) {
+		/* status of companion is 0 at this point */
+		action = evaluate_conflict_action(drp_ie, ext_beacon_slot, rsv, 0);
+		if (uwb_rsv_is_owner(rsv)) {
+			switch(action) {
+			case UWB_DRP_CONFLICT_ACT2:
+			case UWB_DRP_CONFLICT_ACT3:
+				uwb_rsv_set_state(rsv,
+						UWB_RSV_STATE_O_ESTABLISHED);
+				rsv->needs_release_companion_mas = false;
+				if (bow->can_reserve_extra_mases == false)
+					uwb_rsv_backoff_win_increment(rc);
+				uwb_drp_avail_release(rsv->rc,
+						&rsv->mv.companion_mas);
+			}
+		} else { /* rsv is target */
+			switch(action) {
+			case UWB_DRP_CONFLICT_ACT2:
+			case UWB_DRP_CONFLICT_ACT3:
+				uwb_rsv_set_state(rsv,
+					UWB_RSV_STATE_T_EXPANDING_CONFLICT);
+                                /* send_drp_avail_ie = true; */
+			}
+		}
+	} else { /* also base part of the reservation is conflicting */
+		if (uwb_rsv_is_owner(rsv)) {
+			uwb_rsv_backoff_win_increment(rc);
+			/* remove companion part */
+			uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
+
+			/* drop some mases with reason modified */
+
+			/* put in the companion the mases to be dropped */
+			bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm,
+					conflicting_mas->bm, UWB_NUM_MAS);
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MODIFIED);
+		} else { /* it is a target rsv */
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_CONFLICT);
+                        /* send_drp_avail_ie = true; */
+		}
+	}
+}
+
+static void uwb_drp_handle_conflict_rsv(struct uwb_rc *rc, struct uwb_rsv *rsv,
+					struct uwb_rc_evt_drp *drp_evt,
+					struct uwb_ie_drp *drp_ie,
+					struct uwb_mas_bm *conflicting_mas)
+{
+	struct uwb_rsv_move *mv;
+
+	/* check if the conflicting reservation has two drp_ies */
+	if (uwb_rsv_has_two_drp_ies(rsv)) {
+		mv = &rsv->mv;
+		if (bitmap_intersects(rsv->mas.bm, conflicting_mas->bm,
+								UWB_NUM_MAS)) {
+			handle_conflict_expanding(drp_ie,
+						drp_evt->beacon_slot_number,
+						rsv, false, conflicting_mas);
+		} else {
+			if (bitmap_intersects(mv->companion_mas.bm,
+					conflicting_mas->bm, UWB_NUM_MAS)) {
+				handle_conflict_expanding(
+					drp_ie, drp_evt->beacon_slot_number,
+					rsv, true, conflicting_mas);
+			}
+		}
+	} else if (bitmap_intersects(rsv->mas.bm, conflicting_mas->bm,
+							UWB_NUM_MAS)) {
+		handle_conflict_normal(drp_ie, drp_evt->beacon_slot_number,
+					rsv, conflicting_mas);
+	}
+}
+
+static void uwb_drp_handle_all_conflict_rsv(struct uwb_rc *rc,
+					    struct uwb_rc_evt_drp *drp_evt,
+					    struct uwb_ie_drp *drp_ie,
+					    struct uwb_mas_bm *conflicting_mas)
+{
+	struct uwb_rsv *rsv;
+
+	list_for_each_entry(rsv, &rc->reservations, rc_node) {
+		uwb_drp_handle_conflict_rsv(rc, rsv, drp_evt, drp_ie,
+							conflicting_mas);
+	}
+}
+
+static void uwb_drp_process_target_accepted(struct uwb_rc *rc,
+	struct uwb_rsv *rsv, struct uwb_rc_evt_drp *drp_evt,
+	struct uwb_ie_drp *drp_ie, struct uwb_mas_bm *mas)
+{
+	struct uwb_rsv_move *mv = &rsv->mv;
+	int status;
+
+	status = uwb_ie_drp_status(drp_ie);
+
+	if (rsv->state == UWB_RSV_STATE_T_CONFLICT) {
+		uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_CONFLICT);
+		return;
+	}
+
+	if (rsv->state == UWB_RSV_STATE_T_EXPANDING_ACCEPTED) {
+		/* drp_ie is companion */
+		if (!bitmap_equal(rsv->mas.bm, mas->bm, UWB_NUM_MAS)) {
+			/* stroke companion */
+			uwb_rsv_set_state(rsv,
+				UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
+		}
+	} else {
+		if (!bitmap_equal(rsv->mas.bm, mas->bm, UWB_NUM_MAS)) {
+			if (uwb_drp_avail_reserve_pending(rc, mas) == -EBUSY) {
+				/* FIXME: there is a conflict, find
+				 * the conflicting reservations and
+				 * take a sensible action. Consider
+				 * that in drp_ie there is the
+				 * "neighbour" */
+				uwb_drp_handle_all_conflict_rsv(rc, drp_evt,
+						drp_ie, mas);
+			} else {
+				/* accept the extra reservation */
+				bitmap_copy(mv->companion_mas.bm, mas->bm,
+								UWB_NUM_MAS);
+				uwb_rsv_set_state(rsv,
+					UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
+			}
+		} else {
+			if (status) {
+				uwb_rsv_set_state(rsv,
+						UWB_RSV_STATE_T_ACCEPTED);
+			}
+		}
+
+	}
+}
+
+/*
+ * Based on the DRP IE, transition a target reservation to a new
+ * state.
+ */
+static void uwb_drp_process_target(struct uwb_rc *rc, struct uwb_rsv *rsv,
+		   struct uwb_ie_drp *drp_ie, struct uwb_rc_evt_drp *drp_evt)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_rsv_move *mv = &rsv->mv;
+	int status;
+	enum uwb_drp_reason reason_code;
+	struct uwb_mas_bm mas;
+
+	status = uwb_ie_drp_status(drp_ie);
+	reason_code = uwb_ie_drp_reason_code(drp_ie);
+	uwb_drp_ie_to_bm(&mas, drp_ie);
+
+	switch (reason_code) {
+	case UWB_DRP_REASON_ACCEPTED:
+		uwb_drp_process_target_accepted(rc, rsv, drp_evt, drp_ie, &mas);
+		break;
+
+	case UWB_DRP_REASON_MODIFIED:
+		/* check to see if we have already modified the reservation */
+		if (bitmap_equal(rsv->mas.bm, mas.bm, UWB_NUM_MAS)) {
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
+			break;
+		}
+
+		/* find if the owner wants to expand or reduce */
+		if (bitmap_subset(mas.bm, rsv->mas.bm, UWB_NUM_MAS)) {
+			/* owner is reducing */
+			bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, mas.bm,
+				UWB_NUM_MAS);
+			uwb_drp_avail_release(rsv->rc, &mv->companion_mas);
+		}
+
+		bitmap_copy(rsv->mas.bm, mas.bm, UWB_NUM_MAS);
+		uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_RESIZED);
+		break;
+	default:
+		dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
+			 reason_code, status);
+	}
+}
+
+static void uwb_drp_process_owner_accepted(struct uwb_rsv *rsv,
+						struct uwb_mas_bm *mas)
+{
+	struct uwb_rsv_move *mv = &rsv->mv;
+
+	switch (rsv->state) {
+	case UWB_RSV_STATE_O_PENDING:
+	case UWB_RSV_STATE_O_INITIATED:
+	case UWB_RSV_STATE_O_ESTABLISHED:
+		uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
+		break;
+	case UWB_RSV_STATE_O_MODIFIED:
+		if (bitmap_equal(mas->bm, rsv->mas.bm, UWB_NUM_MAS))
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
+		else
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MODIFIED);
+		break;
+
+	case UWB_RSV_STATE_O_MOVE_REDUCING: /* shouldn' t be a problem */
+		if (bitmap_equal(mas->bm, rsv->mas.bm, UWB_NUM_MAS))
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
+		else
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
+		break;
+	case UWB_RSV_STATE_O_MOVE_EXPANDING:
+		if (bitmap_equal(mas->bm, mv->companion_mas.bm, UWB_NUM_MAS)) {
+			/* Companion reservation accepted */
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
+		} else {
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
+		}
+		break;
+	case UWB_RSV_STATE_O_MOVE_COMBINING:
+		if (bitmap_equal(mas->bm, rsv->mas.bm, UWB_NUM_MAS))
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
+		else
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
+		break;
+	default:
+		break;
+	}
+}
+/*
+ * Based on the DRP IE, transition an owner reservation to a new
+ * state.
+ */
+static void uwb_drp_process_owner(struct uwb_rc *rc, struct uwb_rsv *rsv,
+				  struct uwb_dev *src, struct uwb_ie_drp *drp_ie,
+				  struct uwb_rc_evt_drp *drp_evt)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	int status;
+	enum uwb_drp_reason reason_code;
+	struct uwb_mas_bm mas;
+
+	status = uwb_ie_drp_status(drp_ie);
+	reason_code = uwb_ie_drp_reason_code(drp_ie);
+	uwb_drp_ie_to_bm(&mas, drp_ie);
+
+	if (status) {
+		switch (reason_code) {
+		case UWB_DRP_REASON_ACCEPTED:
+			uwb_drp_process_owner_accepted(rsv, &mas);
+			break;
+		default:
+			dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
+				 reason_code, status);
+		}
+	} else {
+		switch (reason_code) {
+		case UWB_DRP_REASON_PENDING:
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_PENDING);
+			break;
+		case UWB_DRP_REASON_DENIED:
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
+			break;
+		case UWB_DRP_REASON_CONFLICT:
+			/* resolve the conflict */
+			bitmap_complement(mas.bm, src->last_availability_bm,
+					  UWB_NUM_MAS);
+			uwb_drp_handle_conflict_rsv(rc, rsv, drp_evt, drp_ie, &mas);
+			break;
+		default:
+			dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
+				 reason_code, status);
+		}
+	}
+}
+
+static void uwb_cnflt_alien_stroke_timer(struct uwb_cnflt_alien *cnflt)
+{
+	unsigned timeout_us = UWB_MAX_LOST_BEACONS * UWB_SUPERFRAME_LENGTH_US;
+	mod_timer(&cnflt->timer, jiffies + usecs_to_jiffies(timeout_us));
+}
+
+static void uwb_cnflt_update_work(struct work_struct *work)
+{
+	struct uwb_cnflt_alien *cnflt = container_of(work,
+						     struct uwb_cnflt_alien,
+						     cnflt_update_work);
+	struct uwb_cnflt_alien *c;
+	struct uwb_rc *rc = cnflt->rc;
+
+	unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
+
+	mutex_lock(&rc->rsvs_mutex);
+
+	list_del(&cnflt->rc_node);
+
+	/* update rc global conflicting alien bitmap */
+	bitmap_zero(rc->cnflt_alien_bitmap.bm, UWB_NUM_MAS);
+
+	list_for_each_entry(c, &rc->cnflt_alien_list, rc_node) {
+		bitmap_or(rc->cnflt_alien_bitmap.bm, rc->cnflt_alien_bitmap.bm,
+						c->mas.bm, UWB_NUM_MAS);
+	}
+
+	queue_delayed_work(rc->rsv_workq, &rc->rsv_alien_bp_work,
+					usecs_to_jiffies(delay_us));
+
+	kfree(cnflt);
+	mutex_unlock(&rc->rsvs_mutex);
+}
+
+static void uwb_cnflt_timer(struct timer_list *t)
+{
+	struct uwb_cnflt_alien *cnflt = from_timer(cnflt, t, timer);
+
+	queue_work(cnflt->rc->rsv_workq, &cnflt->cnflt_update_work);
+}
+
+/*
+ * We have received an DRP_IE of type Alien BP and we need to make
+ * sure we do not transmit in conflicting MASs.
+ */
+static void uwb_drp_handle_alien_drp(struct uwb_rc *rc, struct uwb_ie_drp *drp_ie)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_mas_bm mas;
+	struct uwb_cnflt_alien *cnflt;
+	unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
+
+	uwb_drp_ie_to_bm(&mas, drp_ie);
+
+	list_for_each_entry(cnflt, &rc->cnflt_alien_list, rc_node) {
+		if (bitmap_equal(cnflt->mas.bm, mas.bm, UWB_NUM_MAS)) {
+			/* Existing alien BP reservation conflicting
+			 * bitmap, just reset the timer */
+			uwb_cnflt_alien_stroke_timer(cnflt);
+			return;
+		}
+	}
+
+	/* New alien BP reservation conflicting bitmap */
+
+	/* alloc and initialize new uwb_cnflt_alien */
+	cnflt = kzalloc(sizeof(struct uwb_cnflt_alien), GFP_KERNEL);
+	if (!cnflt) {
+		dev_err(dev, "failed to alloc uwb_cnflt_alien struct\n");
+		return;
+	}
+
+	INIT_LIST_HEAD(&cnflt->rc_node);
+	timer_setup(&cnflt->timer, uwb_cnflt_timer, 0);
+
+	cnflt->rc = rc;
+	INIT_WORK(&cnflt->cnflt_update_work, uwb_cnflt_update_work);
+
+	bitmap_copy(cnflt->mas.bm, mas.bm, UWB_NUM_MAS);
+
+	list_add_tail(&cnflt->rc_node, &rc->cnflt_alien_list);
+
+	/* update rc global conflicting alien bitmap */
+	bitmap_or(rc->cnflt_alien_bitmap.bm, rc->cnflt_alien_bitmap.bm, mas.bm, UWB_NUM_MAS);
+
+	queue_delayed_work(rc->rsv_workq, &rc->rsv_alien_bp_work, usecs_to_jiffies(delay_us));
+
+	/* start the timer */
+	uwb_cnflt_alien_stroke_timer(cnflt);
+}
+
+static void uwb_drp_process_not_involved(struct uwb_rc *rc,
+					 struct uwb_rc_evt_drp *drp_evt,
+					 struct uwb_ie_drp *drp_ie)
+{
+	struct uwb_mas_bm mas;
+
+	uwb_drp_ie_to_bm(&mas, drp_ie);
+	uwb_drp_handle_all_conflict_rsv(rc, drp_evt, drp_ie, &mas);
+}
+
+static void uwb_drp_process_involved(struct uwb_rc *rc, struct uwb_dev *src,
+				     struct uwb_rc_evt_drp *drp_evt,
+				     struct uwb_ie_drp *drp_ie)
+{
+	struct uwb_rsv *rsv;
+
+	rsv = uwb_rsv_find(rc, src, drp_ie);
+	if (!rsv) {
+		/*
+		 * No reservation? It's either for a recently
+		 * terminated reservation; or the DRP IE couldn't be
+		 * processed (e.g., an invalid IE or out of memory).
+		 */
+		return;
+	}
+
+	/*
+	 * Do nothing with DRP IEs for reservations that have been
+	 * terminated.
+	 */
+	if (rsv->state == UWB_RSV_STATE_NONE) {
+		uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
+		return;
+	}
+
+	if (uwb_ie_drp_owner(drp_ie))
+		uwb_drp_process_target(rc, rsv, drp_ie, drp_evt);
+	else
+		uwb_drp_process_owner(rc, rsv, src, drp_ie, drp_evt);
+
+}
+
+
+static bool uwb_drp_involves_us(struct uwb_rc *rc, struct uwb_ie_drp *drp_ie)
+{
+	return uwb_dev_addr_cmp(&rc->uwb_dev.dev_addr, &drp_ie->dev_addr) == 0;
+}
+
+/*
+ * Process a received DRP IE.
+ */
+static void uwb_drp_process(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt,
+			    struct uwb_dev *src, struct uwb_ie_drp *drp_ie)
+{
+	if (uwb_ie_drp_type(drp_ie) == UWB_DRP_TYPE_ALIEN_BP)
+		uwb_drp_handle_alien_drp(rc, drp_ie);
+	else if (uwb_drp_involves_us(rc, drp_ie))
+		uwb_drp_process_involved(rc, src, drp_evt, drp_ie);
+	else
+		uwb_drp_process_not_involved(rc, drp_evt, drp_ie);
+}
+
+/*
+ * Process a received DRP Availability IE
+ */
+static void uwb_drp_availability_process(struct uwb_rc *rc, struct uwb_dev *src,
+					 struct uwb_ie_drp_avail *drp_availability_ie)
+{
+	bitmap_copy(src->last_availability_bm,
+		    drp_availability_ie->bmp, UWB_NUM_MAS);
+}
+
+/*
+ * Process all the DRP IEs (both DRP IEs and the DRP Availability IE)
+ * from a device.
+ */
+static
+void uwb_drp_process_all(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt,
+			 size_t ielen, struct uwb_dev *src_dev)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_ie_hdr *ie_hdr;
+	void *ptr;
+
+	ptr = drp_evt->ie_data;
+	for (;;) {
+		ie_hdr = uwb_ie_next(&ptr, &ielen);
+		if (!ie_hdr)
+			break;
+
+		switch (ie_hdr->element_id) {
+		case UWB_IE_DRP_AVAILABILITY:
+			uwb_drp_availability_process(rc, src_dev, (struct uwb_ie_drp_avail *)ie_hdr);
+			break;
+		case UWB_IE_DRP:
+			uwb_drp_process(rc, drp_evt, src_dev, (struct uwb_ie_drp *)ie_hdr);
+			break;
+		default:
+			dev_warn(dev, "unexpected IE in DRP notification\n");
+			break;
+		}
+	}
+
+	if (ielen > 0)
+		dev_warn(dev, "%d octets remaining in DRP notification\n",
+			 (int)ielen);
+}
+
+/**
+ * uwbd_evt_handle_rc_drp - handle a DRP_IE event
+ * @evt: the DRP_IE event from the radio controller
+ *
+ * This processes DRP notifications from the radio controller, either
+ * initiating a new reservation or transitioning an existing
+ * reservation into a different state.
+ *
+ * DRP notifications can occur for three different reasons:
+ *
+ * - UWB_DRP_NOTIF_DRP_IE_RECVD: one or more DRP IEs with the RC as
+ *   the target or source have been received.
+ *
+ *   These DRP IEs could be new or for an existing reservation.
+ *
+ *   If the DRP IE for an existing reservation ceases to be to
+ *   received for at least mMaxLostBeacons, the reservation should be
+ *   considered to be terminated.  Note that the TERMINATE reason (see
+ *   below) may not always be signalled (e.g., the remote device has
+ *   two or more reservations established with the RC).
+ *
+ * - UWB_DRP_NOTIF_CONFLICT: DRP IEs from any device in the beacon
+ *   group conflict with the RC's reservations.
+ *
+ * - UWB_DRP_NOTIF_TERMINATE: DRP IEs are no longer being received
+ *   from a device (i.e., it's terminated all reservations).
+ *
+ * Only the software state of the reservations is changed; the setting
+ * of the radio controller's DRP IEs is done after all the events in
+ * an event buffer are processed.  This saves waiting multiple times
+ * for the SET_DRP_IE command to complete.
+ */
+int uwbd_evt_handle_rc_drp(struct uwb_event *evt)
+{
+	struct device *dev = &evt->rc->uwb_dev.dev;
+	struct uwb_rc *rc = evt->rc;
+	struct uwb_rc_evt_drp *drp_evt;
+	size_t ielength, bytes_left;
+	struct uwb_dev_addr src_addr;
+	struct uwb_dev *src_dev;
+
+	/* Is there enough data to decode the event (and any IEs in
+	   its payload)? */
+	if (evt->notif.size < sizeof(*drp_evt)) {
+		dev_err(dev, "DRP event: Not enough data to decode event "
+			"[%zu bytes left, %zu needed]\n",
+			evt->notif.size, sizeof(*drp_evt));
+		return 0;
+	}
+	bytes_left = evt->notif.size - sizeof(*drp_evt);
+	drp_evt = container_of(evt->notif.rceb, struct uwb_rc_evt_drp, rceb);
+	ielength = le16_to_cpu(drp_evt->ie_length);
+	if (bytes_left != ielength) {
+		dev_err(dev, "DRP event: Not enough data in payload [%zu"
+			"bytes left, %zu declared in the event]\n",
+			bytes_left, ielength);
+		return 0;
+	}
+
+	memcpy(src_addr.data, &drp_evt->src_addr, sizeof(src_addr));
+	src_dev = uwb_dev_get_by_devaddr(rc, &src_addr);
+	if (!src_dev) {
+		/*
+		 * A DRP notification from an unrecognized device.
+		 *
+		 * This is probably from a WUSB device that doesn't
+		 * have an EUI-48 and therefore doesn't show up in the
+		 * UWB device database.  It's safe to simply ignore
+		 * these.
+		 */
+		return 0;
+	}
+
+	mutex_lock(&rc->rsvs_mutex);
+
+	/* We do not distinguish from the reason */
+	uwb_drp_process_all(rc, drp_evt, ielength, src_dev);
+
+	mutex_unlock(&rc->rsvs_mutex);
+
+	uwb_dev_put(src_dev);
+	return 0;
+}