Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1011 insertions, 0 deletions

diff --git a/drivers/uwb/rsv.c b/drivers/uwb/rsv.c
new file mode 100644
index 000000000..fe25a8cc6
--- /dev/null
+++ b/drivers/uwb/rsv.c
@@ -0,0 +1,1011 @@
+/*
+ * UWB reservation management.
+ *
+ * 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/kernel.h>
+#include <linux/uwb.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/export.h>
+
+#include "uwb-internal.h"
+
+static void uwb_rsv_timer(struct timer_list *t);
+
+static const char *rsv_states[] = {
+	[UWB_RSV_STATE_NONE]                 = "none            ",
+	[UWB_RSV_STATE_O_INITIATED]          = "o initiated     ",
+	[UWB_RSV_STATE_O_PENDING]            = "o pending       ",
+	[UWB_RSV_STATE_O_MODIFIED]           = "o modified      ",
+	[UWB_RSV_STATE_O_ESTABLISHED]        = "o established   ",
+	[UWB_RSV_STATE_O_TO_BE_MOVED]        = "o to be moved   ",
+	[UWB_RSV_STATE_O_MOVE_EXPANDING]     = "o move expanding",
+	[UWB_RSV_STATE_O_MOVE_COMBINING]     = "o move combining",
+	[UWB_RSV_STATE_O_MOVE_REDUCING]      = "o move reducing ",
+	[UWB_RSV_STATE_T_ACCEPTED]           = "t accepted      ",
+	[UWB_RSV_STATE_T_CONFLICT]           = "t conflict      ",
+	[UWB_RSV_STATE_T_PENDING]            = "t pending       ",
+	[UWB_RSV_STATE_T_DENIED]             = "t denied        ",
+	[UWB_RSV_STATE_T_RESIZED]            = "t resized       ",
+	[UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = "t expanding acc ",
+	[UWB_RSV_STATE_T_EXPANDING_CONFLICT] = "t expanding conf",
+	[UWB_RSV_STATE_T_EXPANDING_PENDING]  = "t expanding pend",
+	[UWB_RSV_STATE_T_EXPANDING_DENIED]   = "t expanding den ",
+};
+
+static const char *rsv_types[] = {
+	[UWB_DRP_TYPE_ALIEN_BP] = "alien-bp",
+	[UWB_DRP_TYPE_HARD]     = "hard",
+	[UWB_DRP_TYPE_SOFT]     = "soft",
+	[UWB_DRP_TYPE_PRIVATE]  = "private",
+	[UWB_DRP_TYPE_PCA]      = "pca",
+};
+
+bool uwb_rsv_has_two_drp_ies(struct uwb_rsv *rsv)
+{
+	static const bool has_two_drp_ies[] = {
+		[UWB_RSV_STATE_O_INITIATED]               = false,
+		[UWB_RSV_STATE_O_PENDING]                 = false,
+		[UWB_RSV_STATE_O_MODIFIED]                = false,
+		[UWB_RSV_STATE_O_ESTABLISHED]             = false,
+		[UWB_RSV_STATE_O_TO_BE_MOVED]             = false,
+		[UWB_RSV_STATE_O_MOVE_COMBINING]          = false,
+		[UWB_RSV_STATE_O_MOVE_REDUCING]           = false,
+		[UWB_RSV_STATE_O_MOVE_EXPANDING]          = true,
+		[UWB_RSV_STATE_T_ACCEPTED]                = false,
+		[UWB_RSV_STATE_T_CONFLICT]                = false,
+		[UWB_RSV_STATE_T_PENDING]                 = false,
+		[UWB_RSV_STATE_T_DENIED]                  = false,
+		[UWB_RSV_STATE_T_RESIZED]                 = false,
+		[UWB_RSV_STATE_T_EXPANDING_ACCEPTED]      = true,
+		[UWB_RSV_STATE_T_EXPANDING_CONFLICT]      = true,
+		[UWB_RSV_STATE_T_EXPANDING_PENDING]       = true,
+		[UWB_RSV_STATE_T_EXPANDING_DENIED]        = true,
+	};
+
+	return has_two_drp_ies[rsv->state];
+}
+
+/**
+ * uwb_rsv_state_str - return a string for a reservation state
+ * @state: the reservation state.
+ */
+const char *uwb_rsv_state_str(enum uwb_rsv_state state)
+{
+	if (state < UWB_RSV_STATE_NONE || state >= UWB_RSV_STATE_LAST)
+		return "unknown";
+	return rsv_states[state];
+}
+EXPORT_SYMBOL_GPL(uwb_rsv_state_str);
+
+/**
+ * uwb_rsv_type_str - return a string for a reservation type
+ * @type: the reservation type
+ */
+const char *uwb_rsv_type_str(enum uwb_drp_type type)
+{
+	if (type < UWB_DRP_TYPE_ALIEN_BP || type > UWB_DRP_TYPE_PCA)
+		return "invalid";
+	return rsv_types[type];
+}
+EXPORT_SYMBOL_GPL(uwb_rsv_type_str);
+
+void uwb_rsv_dump(char *text, struct uwb_rsv *rsv)
+{
+	struct device *dev = &rsv->rc->uwb_dev.dev;
+	struct uwb_dev_addr devaddr;
+	char owner[UWB_ADDR_STRSIZE], target[UWB_ADDR_STRSIZE];
+
+	uwb_dev_addr_print(owner, sizeof(owner), &rsv->owner->dev_addr);
+	if (rsv->target.type == UWB_RSV_TARGET_DEV)
+		devaddr = rsv->target.dev->dev_addr;
+	else
+		devaddr = rsv->target.devaddr;
+	uwb_dev_addr_print(target, sizeof(target), &devaddr);
+
+	dev_dbg(dev, "rsv %s %s -> %s: %s\n",
+		text, owner, target, uwb_rsv_state_str(rsv->state));
+}
+
+static void uwb_rsv_release(struct kref *kref)
+{
+	struct uwb_rsv *rsv = container_of(kref, struct uwb_rsv, kref);
+
+	kfree(rsv);
+}
+
+void uwb_rsv_get(struct uwb_rsv *rsv)
+{
+	kref_get(&rsv->kref);
+}
+
+void uwb_rsv_put(struct uwb_rsv *rsv)
+{
+	kref_put(&rsv->kref, uwb_rsv_release);
+}
+
+/*
+ * Get a free stream index for a reservation.
+ *
+ * If the target is a DevAddr (e.g., a WUSB cluster reservation) then
+ * the stream is allocated from a pool of per-RC stream indexes,
+ * otherwise a unique stream index for the target is selected.
+ */
+static int uwb_rsv_get_stream(struct uwb_rsv *rsv)
+{
+	struct uwb_rc *rc = rsv->rc;
+	struct device *dev = &rc->uwb_dev.dev;
+	unsigned long *streams_bm;
+	int stream;
+
+	switch (rsv->target.type) {
+	case UWB_RSV_TARGET_DEV:
+		streams_bm = rsv->target.dev->streams;
+		break;
+	case UWB_RSV_TARGET_DEVADDR:
+		streams_bm = rc->uwb_dev.streams;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	stream = find_first_zero_bit(streams_bm, UWB_NUM_STREAMS);
+	if (stream >= UWB_NUM_STREAMS) {
+		dev_err(dev, "%s: no available stream found\n", __func__);
+		return -EBUSY;
+	}
+
+	rsv->stream = stream;
+	set_bit(stream, streams_bm);
+
+	dev_dbg(dev, "get stream %d\n", rsv->stream);
+
+	return 0;
+}
+
+static void uwb_rsv_put_stream(struct uwb_rsv *rsv)
+{
+	struct uwb_rc *rc = rsv->rc;
+	struct device *dev = &rc->uwb_dev.dev;
+	unsigned long *streams_bm;
+
+	switch (rsv->target.type) {
+	case UWB_RSV_TARGET_DEV:
+		streams_bm = rsv->target.dev->streams;
+		break;
+	case UWB_RSV_TARGET_DEVADDR:
+		streams_bm = rc->uwb_dev.streams;
+		break;
+	default:
+		return;
+	}
+
+	clear_bit(rsv->stream, streams_bm);
+
+	dev_dbg(dev, "put stream %d\n", rsv->stream);
+}
+
+void uwb_rsv_backoff_win_timer(struct timer_list *t)
+{
+	struct uwb_drp_backoff_win *bow = from_timer(bow, t, timer);
+	struct uwb_rc *rc = container_of(bow, struct uwb_rc, bow);
+	struct device *dev = &rc->uwb_dev.dev;
+
+	bow->can_reserve_extra_mases = true;
+	if (bow->total_expired <= 4) {
+		bow->total_expired++;
+	} else {
+		/* after 4 backoff window has expired we can exit from
+		 * the backoff procedure */
+		bow->total_expired = 0;
+		bow->window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
+	}
+	dev_dbg(dev, "backoff_win_timer total_expired=%d, n=%d\n", bow->total_expired, bow->n);
+
+	/* try to relocate all the "to be moved" relocations */
+	uwb_rsv_handle_drp_avail_change(rc);
+}
+
+void uwb_rsv_backoff_win_increment(struct uwb_rc *rc)
+{
+	struct uwb_drp_backoff_win *bow = &rc->bow;
+	struct device *dev = &rc->uwb_dev.dev;
+	unsigned timeout_us;
+
+	dev_dbg(dev, "backoff_win_increment: window=%d\n", bow->window);
+
+	bow->can_reserve_extra_mases = false;
+
+	if((bow->window << 1) == UWB_DRP_BACKOFF_WIN_MAX)
+		return;
+
+	bow->window <<= 1;
+	bow->n = prandom_u32() & (bow->window - 1);
+	dev_dbg(dev, "new_window=%d, n=%d\n", bow->window, bow->n);
+
+	/* reset the timer associated variables */
+	timeout_us = bow->n * UWB_SUPERFRAME_LENGTH_US;
+	bow->total_expired = 0;
+	mod_timer(&bow->timer, jiffies + usecs_to_jiffies(timeout_us));
+}
+
+static void uwb_rsv_stroke_timer(struct uwb_rsv *rsv)
+{
+	int sframes = UWB_MAX_LOST_BEACONS;
+
+	/*
+	 * Multicast reservations can become established within 1
+	 * super frame and should not be terminated if no response is
+	 * received.
+	 */
+	if (rsv->state == UWB_RSV_STATE_NONE) {
+		sframes = 0;
+	} else if (rsv->is_multicast) {
+		if (rsv->state == UWB_RSV_STATE_O_INITIATED
+		    || rsv->state == UWB_RSV_STATE_O_MOVE_EXPANDING
+		    || rsv->state == UWB_RSV_STATE_O_MOVE_COMBINING
+		    || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING)
+			sframes = 1;
+		if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED)
+			sframes = 0;
+
+	}
+
+	if (sframes > 0) {
+		/*
+		 * Add an additional 2 superframes to account for the
+		 * time to send the SET DRP IE command.
+		 */
+		unsigned timeout_us = (sframes + 2) * UWB_SUPERFRAME_LENGTH_US;
+		mod_timer(&rsv->timer, jiffies + usecs_to_jiffies(timeout_us));
+	} else
+		del_timer(&rsv->timer);
+}
+
+/*
+ * Update a reservations state, and schedule an update of the
+ * transmitted DRP IEs.
+ */
+static void uwb_rsv_state_update(struct uwb_rsv *rsv,
+				 enum uwb_rsv_state new_state)
+{
+	rsv->state = new_state;
+	rsv->ie_valid = false;
+
+	uwb_rsv_dump("SU", rsv);
+
+	uwb_rsv_stroke_timer(rsv);
+	uwb_rsv_sched_update(rsv->rc);
+}
+
+static void uwb_rsv_callback(struct uwb_rsv *rsv)
+{
+	if (rsv->callback)
+		rsv->callback(rsv);
+}
+
+void uwb_rsv_set_state(struct uwb_rsv *rsv, enum uwb_rsv_state new_state)
+{
+	struct uwb_rsv_move *mv = &rsv->mv;
+
+	if (rsv->state == new_state) {
+		switch (rsv->state) {
+		case UWB_RSV_STATE_O_ESTABLISHED:
+		case UWB_RSV_STATE_O_MOVE_EXPANDING:
+		case UWB_RSV_STATE_O_MOVE_COMBINING:
+		case UWB_RSV_STATE_O_MOVE_REDUCING:
+		case UWB_RSV_STATE_T_ACCEPTED:
+		case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
+		case UWB_RSV_STATE_T_RESIZED:
+		case UWB_RSV_STATE_NONE:
+			uwb_rsv_stroke_timer(rsv);
+			break;
+		default:
+			/* Expecting a state transition so leave timer
+			   as-is. */
+			break;
+		}
+		return;
+	}
+
+	uwb_rsv_dump("SC", rsv);
+
+	switch (new_state) {
+	case UWB_RSV_STATE_NONE:
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_NONE);
+		uwb_rsv_remove(rsv);
+		uwb_rsv_callback(rsv);
+		break;
+	case UWB_RSV_STATE_O_INITIATED:
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_INITIATED);
+		break;
+	case UWB_RSV_STATE_O_PENDING:
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_PENDING);
+		break;
+	case UWB_RSV_STATE_O_MODIFIED:
+		/* in the companion there are the MASes to drop */
+		bitmap_andnot(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MODIFIED);
+		break;
+	case UWB_RSV_STATE_O_ESTABLISHED:
+		if (rsv->state == UWB_RSV_STATE_O_MODIFIED
+		    || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING) {
+			uwb_drp_avail_release(rsv->rc, &mv->companion_mas);
+			rsv->needs_release_companion_mas = false;
+		}
+		uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_ESTABLISHED);
+		uwb_rsv_callback(rsv);
+		break;
+	case UWB_RSV_STATE_O_MOVE_EXPANDING:
+		rsv->needs_release_companion_mas = true;
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
+		break;
+	case UWB_RSV_STATE_O_MOVE_COMBINING:
+		rsv->needs_release_companion_mas = false;
+		uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
+		bitmap_or(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
+		rsv->mas.safe   += mv->companion_mas.safe;
+		rsv->mas.unsafe += mv->companion_mas.unsafe;
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
+		break;
+	case UWB_RSV_STATE_O_MOVE_REDUCING:
+		bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
+		rsv->needs_release_companion_mas = true;
+		rsv->mas.safe   = mv->final_mas.safe;
+		rsv->mas.unsafe = mv->final_mas.unsafe;
+		bitmap_copy(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
+		bitmap_copy(rsv->mas.unsafe_bm, mv->final_mas.unsafe_bm, UWB_NUM_MAS);
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
+		break;
+	case UWB_RSV_STATE_T_ACCEPTED:
+	case UWB_RSV_STATE_T_RESIZED:
+		rsv->needs_release_companion_mas = false;
+		uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_ACCEPTED);
+		uwb_rsv_callback(rsv);
+		break;
+	case UWB_RSV_STATE_T_DENIED:
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_DENIED);
+		break;
+	case UWB_RSV_STATE_T_CONFLICT:
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_CONFLICT);
+		break;
+	case UWB_RSV_STATE_T_PENDING:
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_PENDING);
+		break;
+	case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
+		rsv->needs_release_companion_mas = true;
+		uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
+		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
+		break;
+	default:
+		dev_err(&rsv->rc->uwb_dev.dev, "unhandled state: %s (%d)\n",
+			uwb_rsv_state_str(new_state), new_state);
+	}
+}
+
+static void uwb_rsv_handle_timeout_work(struct work_struct *work)
+{
+	struct uwb_rsv *rsv = container_of(work, struct uwb_rsv,
+					   handle_timeout_work);
+	struct uwb_rc *rc = rsv->rc;
+
+	mutex_lock(&rc->rsvs_mutex);
+
+	uwb_rsv_dump("TO", rsv);
+
+	switch (rsv->state) {
+	case UWB_RSV_STATE_O_INITIATED:
+		if (rsv->is_multicast) {
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
+			goto unlock;
+		}
+		break;
+	case UWB_RSV_STATE_O_MOVE_EXPANDING:
+		if (rsv->is_multicast) {
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
+			goto unlock;
+		}
+		break;
+	case UWB_RSV_STATE_O_MOVE_COMBINING:
+		if (rsv->is_multicast) {
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
+			goto unlock;
+		}
+		break;
+	case UWB_RSV_STATE_O_MOVE_REDUCING:
+		if (rsv->is_multicast) {
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
+			goto unlock;
+		}
+		break;
+	case UWB_RSV_STATE_O_ESTABLISHED:
+		if (rsv->is_multicast)
+			goto unlock;
+		break;
+	case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
+		/*
+		 * The time out could be for the main or of the
+		 * companion DRP, assume it's for the companion and
+		 * drop that first.  A further time out is required to
+		 * drop the main.
+		 */
+		uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
+		uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
+		goto unlock;
+	case UWB_RSV_STATE_NONE:
+		goto unlock;
+	default:
+		break;
+	}
+
+	uwb_rsv_remove(rsv);
+
+unlock:
+	mutex_unlock(&rc->rsvs_mutex);
+}
+
+static struct uwb_rsv *uwb_rsv_alloc(struct uwb_rc *rc)
+{
+	struct uwb_rsv *rsv;
+
+	rsv = kzalloc(sizeof(struct uwb_rsv), GFP_KERNEL);
+	if (!rsv)
+		return NULL;
+
+	INIT_LIST_HEAD(&rsv->rc_node);
+	INIT_LIST_HEAD(&rsv->pal_node);
+	kref_init(&rsv->kref);
+	timer_setup(&rsv->timer, uwb_rsv_timer, 0);
+
+	rsv->rc = rc;
+	INIT_WORK(&rsv->handle_timeout_work, uwb_rsv_handle_timeout_work);
+
+	return rsv;
+}
+
+/**
+ * uwb_rsv_create - allocate and initialize a UWB reservation structure
+ * @rc: the radio controller
+ * @cb: callback to use when the reservation completes or terminates
+ * @pal_priv: data private to the PAL to be passed in the callback
+ *
+ * The callback is called when the state of the reservation changes from:
+ *
+ *   - pending to accepted
+ *   - pending to denined
+ *   - accepted to terminated
+ *   - pending to terminated
+ */
+struct uwb_rsv *uwb_rsv_create(struct uwb_rc *rc, uwb_rsv_cb_f cb, void *pal_priv)
+{
+	struct uwb_rsv *rsv;
+
+	rsv = uwb_rsv_alloc(rc);
+	if (!rsv)
+		return NULL;
+
+	rsv->callback = cb;
+	rsv->pal_priv = pal_priv;
+
+	return rsv;
+}
+EXPORT_SYMBOL_GPL(uwb_rsv_create);
+
+void uwb_rsv_remove(struct uwb_rsv *rsv)
+{
+	uwb_rsv_dump("RM", rsv);
+
+	if (rsv->state != UWB_RSV_STATE_NONE)
+		uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
+
+	if (rsv->needs_release_companion_mas)
+		uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
+	uwb_drp_avail_release(rsv->rc, &rsv->mas);
+
+	if (uwb_rsv_is_owner(rsv))
+		uwb_rsv_put_stream(rsv);
+
+	uwb_dev_put(rsv->owner);
+	if (rsv->target.type == UWB_RSV_TARGET_DEV)
+		uwb_dev_put(rsv->target.dev);
+
+	list_del_init(&rsv->rc_node);
+	uwb_rsv_put(rsv);
+}
+
+/**
+ * uwb_rsv_destroy - free a UWB reservation structure
+ * @rsv: the reservation to free
+ *
+ * The reservation must already be terminated.
+ */
+void uwb_rsv_destroy(struct uwb_rsv *rsv)
+{
+	uwb_rsv_put(rsv);
+}
+EXPORT_SYMBOL_GPL(uwb_rsv_destroy);
+
+/**
+ * usb_rsv_establish - start a reservation establishment
+ * @rsv: the reservation
+ *
+ * The PAL should fill in @rsv's owner, target, type, max_mas,
+ * min_mas, max_interval and is_multicast fields.  If the target is a
+ * uwb_dev it must be referenced.
+ *
+ * The reservation's callback will be called when the reservation is
+ * accepted, denied or times out.
+ */
+int uwb_rsv_establish(struct uwb_rsv *rsv)
+{
+	struct uwb_rc *rc = rsv->rc;
+	struct uwb_mas_bm available;
+	struct device *dev = &rc->uwb_dev.dev;
+	int ret;
+
+	mutex_lock(&rc->rsvs_mutex);
+	ret = uwb_rsv_get_stream(rsv);
+	if (ret) {
+		dev_err(dev, "%s: uwb_rsv_get_stream failed: %d\n",
+			__func__, ret);
+		goto out;
+	}
+
+	rsv->tiebreaker = prandom_u32() & 1;
+	/* get available mas bitmap */
+	uwb_drp_available(rc, &available);
+
+	ret = uwb_rsv_find_best_allocation(rsv, &available, &rsv->mas);
+	if (ret == UWB_RSV_ALLOC_NOT_FOUND) {
+		ret = -EBUSY;
+		uwb_rsv_put_stream(rsv);
+		dev_err(dev, "%s: uwb_rsv_find_best_allocation failed: %d\n",
+			__func__, ret);
+		goto out;
+	}
+
+	ret = uwb_drp_avail_reserve_pending(rc, &rsv->mas);
+	if (ret != 0) {
+		uwb_rsv_put_stream(rsv);
+		dev_err(dev, "%s: uwb_drp_avail_reserve_pending failed: %d\n",
+			__func__, ret);
+		goto out;
+	}
+
+	uwb_rsv_get(rsv);
+	list_add_tail(&rsv->rc_node, &rc->reservations);
+	rsv->owner = &rc->uwb_dev;
+	uwb_dev_get(rsv->owner);
+	uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_INITIATED);
+out:
+	mutex_unlock(&rc->rsvs_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(uwb_rsv_establish);
+
+/**
+ * uwb_rsv_modify - modify an already established reservation
+ * @rsv: the reservation to modify
+ * @max_mas: new maximum MAS to reserve
+ * @min_mas: new minimum MAS to reserve
+ * @max_interval: new max_interval to use
+ *
+ * FIXME: implement this once there are PALs that use it.
+ */
+int uwb_rsv_modify(struct uwb_rsv *rsv, int max_mas, int min_mas, int max_interval)
+{
+	return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(uwb_rsv_modify);
+
+/*
+ * move an already established reservation (rc->rsvs_mutex must to be
+ * taken when tis function is called)
+ */
+int uwb_rsv_try_move(struct uwb_rsv *rsv, struct uwb_mas_bm *available)
+{
+	struct uwb_rc *rc = rsv->rc;
+	struct uwb_drp_backoff_win *bow = &rc->bow;
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_rsv_move *mv;
+	int ret = 0;
+
+	if (bow->can_reserve_extra_mases == false)
+		return -EBUSY;
+
+	mv = &rsv->mv;
+
+	if (uwb_rsv_find_best_allocation(rsv, available, &mv->final_mas) == UWB_RSV_ALLOC_FOUND) {
+
+		if (!bitmap_equal(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS)) {
+			/* We want to move the reservation */
+			bitmap_andnot(mv->companion_mas.bm, mv->final_mas.bm, rsv->mas.bm, UWB_NUM_MAS);
+			uwb_drp_avail_reserve_pending(rc, &mv->companion_mas);
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
+		}
+	} else {
+		dev_dbg(dev, "new allocation not found\n");
+	}
+
+	return ret;
+}
+
+/* It will try to move every reservation in state O_ESTABLISHED giving
+ * to the MAS allocator algorithm an availability that is the real one
+ * plus the allocation already established from the reservation. */
+void uwb_rsv_handle_drp_avail_change(struct uwb_rc *rc)
+{
+	struct uwb_drp_backoff_win *bow = &rc->bow;
+	struct uwb_rsv *rsv;
+	struct uwb_mas_bm mas;
+
+	if (bow->can_reserve_extra_mases == false)
+		return;
+
+	list_for_each_entry(rsv, &rc->reservations, rc_node) {
+		if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED ||
+		    rsv->state == UWB_RSV_STATE_O_TO_BE_MOVED) {
+			uwb_drp_available(rc, &mas);
+			bitmap_or(mas.bm, mas.bm, rsv->mas.bm, UWB_NUM_MAS);
+			uwb_rsv_try_move(rsv, &mas);
+		}
+	}
+
+}
+
+/**
+ * uwb_rsv_terminate - terminate an established reservation
+ * @rsv: the reservation to terminate
+ *
+ * A reservation is terminated by removing the DRP IE from the beacon,
+ * the other end will consider the reservation to be terminated when
+ * it does not see the DRP IE for at least mMaxLostBeacons.
+ *
+ * If applicable, the reference to the target uwb_dev will be released.
+ */
+void uwb_rsv_terminate(struct uwb_rsv *rsv)
+{
+	struct uwb_rc *rc = rsv->rc;
+
+	mutex_lock(&rc->rsvs_mutex);
+
+	if (rsv->state != UWB_RSV_STATE_NONE)
+		uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
+
+	mutex_unlock(&rc->rsvs_mutex);
+}
+EXPORT_SYMBOL_GPL(uwb_rsv_terminate);
+
+/**
+ * uwb_rsv_accept - accept a new reservation from a peer
+ * @rsv:      the reservation
+ * @cb:       call back for reservation changes
+ * @pal_priv: data to be passed in the above call back
+ *
+ * Reservation requests from peers are denied unless a PAL accepts it
+ * by calling this function.
+ *
+ * The PAL call uwb_rsv_destroy() for all accepted reservations before
+ * calling uwb_pal_unregister().
+ */
+void uwb_rsv_accept(struct uwb_rsv *rsv, uwb_rsv_cb_f cb, void *pal_priv)
+{
+	uwb_rsv_get(rsv);
+
+	rsv->callback = cb;
+	rsv->pal_priv = pal_priv;
+	rsv->state    = UWB_RSV_STATE_T_ACCEPTED;
+}
+EXPORT_SYMBOL_GPL(uwb_rsv_accept);
+
+/*
+ * Is a received DRP IE for this reservation?
+ */
+static bool uwb_rsv_match(struct uwb_rsv *rsv, struct uwb_dev *src,
+			  struct uwb_ie_drp *drp_ie)
+{
+	struct uwb_dev_addr *rsv_src;
+	int stream;
+
+	stream = uwb_ie_drp_stream_index(drp_ie);
+
+	if (rsv->stream != stream)
+		return false;
+
+	switch (rsv->target.type) {
+	case UWB_RSV_TARGET_DEVADDR:
+		return rsv->stream == stream;
+	case UWB_RSV_TARGET_DEV:
+		if (uwb_ie_drp_owner(drp_ie))
+			rsv_src = &rsv->owner->dev_addr;
+		else
+			rsv_src = &rsv->target.dev->dev_addr;
+		return uwb_dev_addr_cmp(&src->dev_addr, rsv_src) == 0;
+	}
+	return false;
+}
+
+static struct uwb_rsv *uwb_rsv_new_target(struct uwb_rc *rc,
+					  struct uwb_dev *src,
+					  struct uwb_ie_drp *drp_ie)
+{
+	struct uwb_rsv *rsv;
+	struct uwb_pal *pal;
+	enum uwb_rsv_state state;
+
+	rsv = uwb_rsv_alloc(rc);
+	if (!rsv)
+		return NULL;
+
+	rsv->rc          = rc;
+	rsv->owner       = src;
+	uwb_dev_get(rsv->owner);
+	rsv->target.type = UWB_RSV_TARGET_DEV;
+	rsv->target.dev  = &rc->uwb_dev;
+	uwb_dev_get(&rc->uwb_dev);
+	rsv->type        = uwb_ie_drp_type(drp_ie);
+	rsv->stream      = uwb_ie_drp_stream_index(drp_ie);
+	uwb_drp_ie_to_bm(&rsv->mas, drp_ie);
+
+	/*
+	 * See if any PALs are interested in this reservation. If not,
+	 * deny the request.
+	 */
+	rsv->state = UWB_RSV_STATE_T_DENIED;
+	mutex_lock(&rc->uwb_dev.mutex);
+	list_for_each_entry(pal, &rc->pals, node) {
+		if (pal->new_rsv)
+			pal->new_rsv(pal, rsv);
+		if (rsv->state == UWB_RSV_STATE_T_ACCEPTED)
+			break;
+	}
+	mutex_unlock(&rc->uwb_dev.mutex);
+
+	list_add_tail(&rsv->rc_node, &rc->reservations);
+	state = rsv->state;
+	rsv->state = UWB_RSV_STATE_NONE;
+
+	/* FIXME: do something sensible here */
+	if (state == UWB_RSV_STATE_T_ACCEPTED
+	    && uwb_drp_avail_reserve_pending(rc, &rsv->mas) == -EBUSY) {
+		/* FIXME: do something sensible here */
+	} else {
+		uwb_rsv_set_state(rsv, state);
+	}
+
+	return rsv;
+}
+
+/**
+ * uwb_rsv_get_usable_mas - get the bitmap of the usable MAS of a reservations
+ * @rsv: the reservation.
+ * @mas: returns the available MAS.
+ *
+ * The usable MAS of a reservation may be less than the negotiated MAS
+ * if alien BPs are present.
+ */
+void uwb_rsv_get_usable_mas(struct uwb_rsv *rsv, struct uwb_mas_bm *mas)
+{
+	bitmap_zero(mas->bm, UWB_NUM_MAS);
+	bitmap_andnot(mas->bm, rsv->mas.bm, rsv->rc->cnflt_alien_bitmap.bm, UWB_NUM_MAS);
+}
+EXPORT_SYMBOL_GPL(uwb_rsv_get_usable_mas);
+
+/**
+ * uwb_rsv_find - find a reservation for a received DRP IE.
+ * @rc: the radio controller
+ * @src: source of the DRP IE
+ * @drp_ie: the DRP IE
+ *
+ * If the reservation cannot be found and the DRP IE is from a peer
+ * attempting to establish a new reservation, create a new reservation
+ * and add it to the list.
+ */
+struct uwb_rsv *uwb_rsv_find(struct uwb_rc *rc, struct uwb_dev *src,
+			     struct uwb_ie_drp *drp_ie)
+{
+	struct uwb_rsv *rsv;
+
+	list_for_each_entry(rsv, &rc->reservations, rc_node) {
+		if (uwb_rsv_match(rsv, src, drp_ie))
+			return rsv;
+	}
+
+	if (uwb_ie_drp_owner(drp_ie))
+		return uwb_rsv_new_target(rc, src, drp_ie);
+
+	return NULL;
+}
+
+/*
+ * Go through all the reservations and check for timeouts and (if
+ * necessary) update their DRP IEs.
+ *
+ * FIXME: look at building the SET_DRP_IE command here rather than
+ * having to rescan the list in uwb_rc_send_all_drp_ie().
+ */
+static bool uwb_rsv_update_all(struct uwb_rc *rc)
+{
+	struct uwb_rsv *rsv, *t;
+	bool ie_updated = false;
+
+	list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
+		if (!rsv->ie_valid) {
+			uwb_drp_ie_update(rsv);
+			ie_updated = true;
+		}
+	}
+
+	return ie_updated;
+}
+
+void uwb_rsv_queue_update(struct uwb_rc *rc)
+{
+	unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
+
+	queue_delayed_work(rc->rsv_workq, &rc->rsv_update_work, usecs_to_jiffies(delay_us));
+}
+
+/**
+ * uwb_rsv_sched_update - schedule an update of the DRP IEs
+ * @rc: the radio controller.
+ *
+ * To improve performance and ensure correctness with [ECMA-368] the
+ * number of SET-DRP-IE commands that are done are limited.
+ *
+ * DRP IEs update come from two sources: DRP events from the hardware
+ * which all occur at the beginning of the superframe ('syncronous'
+ * events) and reservation establishment/termination requests from
+ * PALs or timers ('asynchronous' events).
+ *
+ * A delayed work ensures that all the synchronous events result in
+ * one SET-DRP-IE command.
+ *
+ * Additional logic (the set_drp_ie_pending and rsv_updated_postponed
+ * flags) will prevent an asynchrous event starting a SET-DRP-IE
+ * command if one is currently awaiting a response.
+ *
+ * FIXME: this does leave a window where an asynchrous event can delay
+ * the SET-DRP-IE for a synchronous event by one superframe.
+ */
+void uwb_rsv_sched_update(struct uwb_rc *rc)
+{
+	spin_lock_irq(&rc->rsvs_lock);
+	if (!delayed_work_pending(&rc->rsv_update_work)) {
+		if (rc->set_drp_ie_pending > 0) {
+			rc->set_drp_ie_pending++;
+			goto unlock;
+		}
+		uwb_rsv_queue_update(rc);
+	}
+unlock:
+	spin_unlock_irq(&rc->rsvs_lock);
+}
+
+/*
+ * Update DRP IEs and, if necessary, the DRP Availability IE and send
+ * the updated IEs to the radio controller.
+ */
+static void uwb_rsv_update_work(struct work_struct *work)
+{
+	struct uwb_rc *rc = container_of(work, struct uwb_rc,
+					 rsv_update_work.work);
+	bool ie_updated;
+
+	mutex_lock(&rc->rsvs_mutex);
+
+	ie_updated = uwb_rsv_update_all(rc);
+
+	if (!rc->drp_avail.ie_valid) {
+		uwb_drp_avail_ie_update(rc);
+		ie_updated = true;
+	}
+
+	if (ie_updated && (rc->set_drp_ie_pending == 0))
+		uwb_rc_send_all_drp_ie(rc);
+
+	mutex_unlock(&rc->rsvs_mutex);
+}
+
+static void uwb_rsv_alien_bp_work(struct work_struct *work)
+{
+	struct uwb_rc *rc = container_of(work, struct uwb_rc,
+					 rsv_alien_bp_work.work);
+	struct uwb_rsv *rsv;
+
+	mutex_lock(&rc->rsvs_mutex);
+
+	list_for_each_entry(rsv, &rc->reservations, rc_node) {
+		if (rsv->type != UWB_DRP_TYPE_ALIEN_BP) {
+			uwb_rsv_callback(rsv);
+		}
+	}
+
+	mutex_unlock(&rc->rsvs_mutex);
+}
+
+static void uwb_rsv_timer(struct timer_list *t)
+{
+	struct uwb_rsv *rsv = from_timer(rsv, t, timer);
+
+	queue_work(rsv->rc->rsv_workq, &rsv->handle_timeout_work);
+}
+
+/**
+ * uwb_rsv_remove_all - remove all reservations
+ * @rc: the radio controller
+ *
+ * A DRP IE update is not done.
+ */
+void uwb_rsv_remove_all(struct uwb_rc *rc)
+{
+	struct uwb_rsv *rsv, *t;
+
+	mutex_lock(&rc->rsvs_mutex);
+	list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
+		if (rsv->state != UWB_RSV_STATE_NONE)
+			uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
+		del_timer_sync(&rsv->timer);
+	}
+	/* Cancel any postponed update. */
+	rc->set_drp_ie_pending = 0;
+	mutex_unlock(&rc->rsvs_mutex);
+
+	cancel_delayed_work_sync(&rc->rsv_update_work);
+	flush_workqueue(rc->rsv_workq);
+
+	mutex_lock(&rc->rsvs_mutex);
+	list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
+		uwb_rsv_remove(rsv);
+	}
+	mutex_unlock(&rc->rsvs_mutex);
+}
+
+void uwb_rsv_init(struct uwb_rc *rc)
+{
+	INIT_LIST_HEAD(&rc->reservations);
+	INIT_LIST_HEAD(&rc->cnflt_alien_list);
+	mutex_init(&rc->rsvs_mutex);
+	spin_lock_init(&rc->rsvs_lock);
+	INIT_DELAYED_WORK(&rc->rsv_update_work, uwb_rsv_update_work);
+	INIT_DELAYED_WORK(&rc->rsv_alien_bp_work, uwb_rsv_alien_bp_work);
+	rc->bow.can_reserve_extra_mases = true;
+	rc->bow.total_expired = 0;
+	rc->bow.window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
+	timer_setup(&rc->bow.timer, uwb_rsv_backoff_win_timer, 0);
+
+	bitmap_complement(rc->uwb_dev.streams, rc->uwb_dev.streams, UWB_NUM_STREAMS);
+}
+
+int uwb_rsv_setup(struct uwb_rc *rc)
+{
+	char name[16];
+
+	snprintf(name, sizeof(name), "%s_rsvd", dev_name(&rc->uwb_dev.dev));
+	rc->rsv_workq = create_singlethread_workqueue(name);
+	if (rc->rsv_workq == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void uwb_rsv_cleanup(struct uwb_rc *rc)
+{
+	uwb_rsv_remove_all(rc);
+	destroy_workqueue(rc->rsv_workq);
+}