uwb: improved MAS allocator and reservation conflict handling

Greatly enhance the MAS allocator:
  - Handle row and column reservations.
  - Permit all the available MAS to be allocated.
  - Follows the WiMedia rules on MAS selection.

Take appropriate action when reservation conflicts are detected.
  - Correctly identify which reservation wins the conflict.
  - Protect alien BP reservations.
  - If an owned reservation loses, resize/move it.
  - Follow the backoff procedure before requesting additional MAS.

When reservations are terminated, move the remaining reservations (if
necessary) so they keep following the MAS allocation rules.

Signed-off-by: Stefano Panella <stefano.panella@csr.com>
Signed-off-by: David Vrabel <david.vrabel@csr.com>

drivers/usb/wusbcore/reservation.c

@@ -48,13 +48,15 @@ static void wusbhc_rsv_complete_cb(struct uwb_rsv *rsv)
 {
 	struct wusbhc *wusbhc = rsv->pal_priv;
 	struct device *dev = wusbhc->dev;
+	struct uwb_mas_bm mas;
 	char buf[72];
 
 	switch (rsv->state) {
 	case UWB_RSV_STATE_O_ESTABLISHED:
-		bitmap_scnprintf(buf, sizeof(buf), rsv->mas.bm, UWB_NUM_MAS);
+		uwb_rsv_get_usable_mas(rsv, &mas);
+		bitmap_scnprintf(buf, sizeof(buf), mas.bm, UWB_NUM_MAS);
 		dev_dbg(dev, "established reservation: %s\n", buf);
-		wusbhc_bwa_set(wusbhc, rsv->stream, &rsv->mas);
+		wusbhc_bwa_set(wusbhc, rsv->stream, &mas);
 		break;
 	case UWB_RSV_STATE_NONE:
 		dev_dbg(dev, "removed reservation\n");
@@ -85,13 +87,12 @@ int wusbhc_rsv_establish(struct wusbhc *wusbhc)
 	bcid.data[0] = wusbhc->cluster_id;
 	bcid.data[1] = 0;
 
-	rsv->owner = &rc->uwb_dev;
 	rsv->target.type = UWB_RSV_TARGET_DEVADDR;
 	rsv->target.devaddr = bcid;
 	rsv->type = UWB_DRP_TYPE_PRIVATE;
-	rsv->max_mas = 256;
-	rsv->min_mas = 16;  /* one MAS per zone? */
-	rsv->sparsity = 16; /* at least one MAS in each zone? */
+	rsv->max_mas = 256; /* try to get as much as possible */
+	rsv->min_mas = 15;  /* one MAS per zone */
+	rsv->max_interval = 1; /* max latency is one zone */
 	rsv->is_multicast = true;
 
 	ret = uwb_rsv_establish(rsv);

drivers/uwb/Makefile

@@ -6,6 +6,7 @@ obj-$(CONFIG_UWB_I1480U)	+= i1480/
 
 uwb-objs :=		\
 	address.o	\
+	allocator.o	\
 	beacon.o	\
 	driver.o	\
 	drp.o		\

drivers/uwb/allocator.c

@@ -0,0 +1,386 @@
+/*
+ * 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/version.h>
+#include <linux/kernel.h>
+#include <linux/uwb.h>
+
+#include "uwb-internal.h"
+
+static void uwb_rsv_fill_column_alloc(struct uwb_rsv_alloc_info *ai)
+{
+	int col, mas, safe_mas, unsafe_mas;
+	unsigned char *bm = ai->bm;
+	struct uwb_rsv_col_info *ci = ai->ci;
+	unsigned char c;
+
+	for (col = ci->csi.start_col; col < UWB_NUM_ZONES; col += ci->csi.interval) {
+    
+		safe_mas   = ci->csi.safe_mas_per_col;
+		unsafe_mas = ci->csi.unsafe_mas_per_col;
+    
+		for (mas = 0; mas < UWB_MAS_PER_ZONE; mas++ ) {
+			if (bm[col * UWB_MAS_PER_ZONE + mas] == 0) {
+	
+				if (safe_mas > 0) {
+					safe_mas--;
+					c = UWB_RSV_MAS_SAFE;
+				} else if (unsafe_mas > 0) {
+					unsafe_mas--;
+					c = UWB_RSV_MAS_UNSAFE;
+				} else {
+					break;
+				}
+				bm[col * UWB_MAS_PER_ZONE + mas] = c;
+			}
+		}
+	}
+}
+
+static void uwb_rsv_fill_row_alloc(struct uwb_rsv_alloc_info *ai)
+{
+	int mas, col, rows;
+	unsigned char *bm = ai->bm;
+	struct uwb_rsv_row_info *ri = &ai->ri;
+	unsigned char c;
+
+	rows = 1;
+	c = UWB_RSV_MAS_SAFE;
+	for (mas = UWB_MAS_PER_ZONE - 1; mas >= 0; mas--) {
+		if (ri->avail[mas] == 1) {
+      
+			if (rows > ri->used_rows) {
+				break;
+			} else if (rows > 7) {
+				c = UWB_RSV_MAS_UNSAFE;
+			}
+
+			for (col = 0; col < UWB_NUM_ZONES; col++) {
+				if (bm[col * UWB_NUM_ZONES + mas] != UWB_RSV_MAS_NOT_AVAIL) {
+					bm[col * UWB_NUM_ZONES + mas] = c;
+					if(c == UWB_RSV_MAS_SAFE)
+						ai->safe_allocated_mases++;
+					else
+						ai->unsafe_allocated_mases++;
+				}
+			}
+			rows++;
+		}
+	}
+	ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
+}
+
+/*
+ * Find the best column set for a given availability, interval, num safe mas and
+ * num unsafe mas.
+ *
+ * The different sets are tried in order as shown below, depending on the interval.
+ *
+ * interval = 16
+ *	deep = 0
+ *		set 1 ->  {  8 }
+ *	deep = 1
+ *		set 1 ->  {  4 }
+ *		set 2 ->  { 12 }
+ *	deep = 2
+ *		set 1 ->  {  2 }
+ *		set 2 ->  {  6 }
+ *		set 3 ->  { 10 }
+ *		set 4 ->  { 14 }
+ *	deep = 3
+ *		set 1 ->  {  1 }
+ *		set 2 ->  {  3 }
+ *		set 3 ->  {  5 }
+ *		set 4 ->  {  7 }
+ *		set 5 ->  {  9 }
+ *		set 6 ->  { 11 }
+ *		set 7 ->  { 13 }
+ *		set 8 ->  { 15 }
+ *
+ * interval = 8
+ *	deep = 0
+ *		set 1 ->  {  4  12 }
+ *	deep = 1
+ *		set 1 ->  {  2  10 }
+ *		set 2 ->  {  6  14 }
+ *	deep = 2
+ *		set 1 ->  {  1   9 }
+ *		set 2 ->  {  3  11 }
+ *		set 3 ->  {  5  13 }
+ *		set 4 ->  {  7  15 }
+ *
+ * interval = 4
+ *	deep = 0
+ *		set 1 ->  {  2   6  10  14 }
+ *	deep = 1
+ *		set 1 ->  {  1   5   9  13 }
+ *		set 2 ->  {  3   7  11  15 }
+ *
+ * interval = 2
+ *	deep = 0
+ *		set 1 ->  {  1   3   5   7   9  11  13  15 }
+ */
+static int uwb_rsv_find_best_column_set(struct uwb_rsv_alloc_info *ai, int interval, 
+					int num_safe_mas, int num_unsafe_mas)
+{
+	struct uwb_rsv_col_info *ci = ai->ci;
+	struct uwb_rsv_col_set_info *csi = &ci->csi;
+	struct uwb_rsv_col_set_info tmp_csi;
+	int deep, set, col, start_col_deep, col_start_set;
+	int start_col, max_mas_in_set, lowest_max_mas_in_deep;
+	int n_mas;
+	int found = UWB_RSV_ALLOC_NOT_FOUND; 
+
+	tmp_csi.start_col = 0;
+	start_col_deep = interval;
+	n_mas = num_unsafe_mas + num_safe_mas;
+
+	for (deep = 0; ((interval >> deep) & 0x1) == 0; deep++) {
+		start_col_deep /= 2;
+		col_start_set = 0;
+		lowest_max_mas_in_deep = UWB_MAS_PER_ZONE;
+
+		for (set = 1; set <= (1 << deep); set++) {
+			max_mas_in_set = 0;
+			start_col = start_col_deep + col_start_set;
+			for (col = start_col; col < UWB_NUM_ZONES; col += interval) {
+                
+				if (ci[col].max_avail_safe >= num_safe_mas &&
+				    ci[col].max_avail_unsafe >= n_mas) {
+					if (ci[col].highest_mas[n_mas] > max_mas_in_set)
+						max_mas_in_set = ci[col].highest_mas[n_mas];
+				} else {
+					max_mas_in_set = 0;
+					break;
+				}
+			}
+			if ((lowest_max_mas_in_deep > max_mas_in_set) && max_mas_in_set) {
+				lowest_max_mas_in_deep = max_mas_in_set;
+
+				tmp_csi.start_col = start_col;
+			}
+			col_start_set += (interval >> deep);
+		}
+
+		if (lowest_max_mas_in_deep < 8) {
+			csi->start_col = tmp_csi.start_col;
+			found = UWB_RSV_ALLOC_FOUND;
+			break;
+		} else if ((lowest_max_mas_in_deep > 8) && 
+			   (lowest_max_mas_in_deep != UWB_MAS_PER_ZONE) &&
+			   (found == UWB_RSV_ALLOC_NOT_FOUND)) {
+			csi->start_col = tmp_csi.start_col;
+			found = UWB_RSV_ALLOC_FOUND;
+		}
+	}
+
+	if (found == UWB_RSV_ALLOC_FOUND) {
+		csi->interval = interval;
+		csi->safe_mas_per_col = num_safe_mas;
+		csi->unsafe_mas_per_col = num_unsafe_mas;
+
+		ai->safe_allocated_mases = (UWB_NUM_ZONES / interval) * num_safe_mas;
+		ai->unsafe_allocated_mases = (UWB_NUM_ZONES / interval) * num_unsafe_mas;
+		ai->total_allocated_mases = ai->safe_allocated_mases + ai->unsafe_allocated_mases;
+		ai->interval = interval;		
+	}
+	return found;
+}
+
+static void get_row_descriptors(struct uwb_rsv_alloc_info *ai)
+{
+	unsigned char *bm = ai->bm;
+	struct uwb_rsv_row_info *ri = &ai->ri;
+	int col, mas;
+  
+	ri->free_rows = 16;
+	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
+		ri->avail[mas] = 1;
+		for (col = 1; col < UWB_NUM_ZONES; col++) {
+			if (bm[col * UWB_NUM_ZONES + mas] == UWB_RSV_MAS_NOT_AVAIL) {
+				ri->free_rows--;
+				ri->avail[mas]=0;
+				break;
+			}
+		}
+	}
+}
+
+static void uwb_rsv_fill_column_info(unsigned char *bm, int column, struct uwb_rsv_col_info *rci)
+{
+	int mas;
+	int block_count = 0, start_block = 0; 
+	int previous_avail = 0;
+	int available = 0;
+	int safe_mas_in_row[UWB_MAS_PER_ZONE] = {
+		8, 7, 6, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 2, 1,
+	};
+
+	rci->max_avail_safe = 0;
+
+	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas ++) {
+		if (!bm[column * UWB_NUM_ZONES + mas]) {
+			available++;
+			rci->max_avail_unsafe = available;
+
+			rci->highest_mas[available] = mas;
+
+			if (previous_avail) {
+				block_count++;
+				if ((block_count > safe_mas_in_row[start_block]) &&
+				    (!rci->max_avail_safe))
+					rci->max_avail_safe = available - 1;
+			} else {
+				previous_avail = 1;
+				start_block = mas;
+				block_count = 1;
+			}
+		} else {
+			previous_avail = 0;
+		}
+	}
+	if (!rci->max_avail_safe)
+		rci->max_avail_safe = rci->max_avail_unsafe;
+}
+
+static void get_column_descriptors(struct uwb_rsv_alloc_info *ai)
+{
+	unsigned char *bm = ai->bm;
+	struct uwb_rsv_col_info *ci = ai->ci;
+	int col;
+
+	for (col = 1; col < UWB_NUM_ZONES; col++) {
+		uwb_rsv_fill_column_info(bm, col, &ci[col]);
+	}
+}
+
+static int uwb_rsv_find_best_row_alloc(struct uwb_rsv_alloc_info *ai)
+{
+	int n_rows;
+	int max_rows = ai->max_mas / UWB_USABLE_MAS_PER_ROW;
+	int min_rows = ai->min_mas / UWB_USABLE_MAS_PER_ROW;
+	if (ai->min_mas % UWB_USABLE_MAS_PER_ROW)
+		min_rows++;
+	for (n_rows = max_rows; n_rows >= min_rows; n_rows--) {
+		if (n_rows <= ai->ri.free_rows) {
+			ai->ri.used_rows = n_rows;
+			ai->interval = 1; /* row reservation */
+			uwb_rsv_fill_row_alloc(ai);
+			return UWB_RSV_ALLOC_FOUND;
+		}
+	}  
+	return UWB_RSV_ALLOC_NOT_FOUND;
+}
+
+static int uwb_rsv_find_best_col_alloc(struct uwb_rsv_alloc_info *ai, int interval)
+{
+	int n_safe, n_unsafe, n_mas;  
+	int n_column = UWB_NUM_ZONES / interval;
+	int max_per_zone = ai->max_mas / n_column;
+	int min_per_zone = ai->min_mas / n_column;
+
+	if (ai->min_mas % n_column)
+		min_per_zone++;
+
+	if (min_per_zone > UWB_MAS_PER_ZONE) {
+		return UWB_RSV_ALLOC_NOT_FOUND;
+	}
+    
+	if (max_per_zone > UWB_MAS_PER_ZONE) {
+		max_per_zone = UWB_MAS_PER_ZONE;
+	}
+    
+	for (n_mas = max_per_zone; n_mas >= min_per_zone; n_mas--) {
+		if (uwb_rsv_find_best_column_set(ai, interval, 0, n_mas) == UWB_RSV_ALLOC_NOT_FOUND)
+			continue;
+		for (n_safe = n_mas; n_safe >= 0; n_safe--) {
+			n_unsafe = n_mas - n_safe;
+			if (uwb_rsv_find_best_column_set(ai, interval, n_safe, n_unsafe) == UWB_RSV_ALLOC_FOUND) {
+				uwb_rsv_fill_column_alloc(ai);
+				return UWB_RSV_ALLOC_FOUND;
+			}
+		}
+	}
+	return UWB_RSV_ALLOC_NOT_FOUND;
+}
+
+int uwb_rsv_find_best_allocation(struct uwb_rsv *rsv, struct uwb_mas_bm *available, 
+				 struct uwb_mas_bm *result)
+{
+	struct uwb_rsv_alloc_info *ai;
+	int interval;
+	int bit_index;
+
+	ai = kzalloc(sizeof(struct uwb_rsv_alloc_info), GFP_KERNEL);
+	
+	ai->min_mas = rsv->min_mas;
+	ai->max_mas = rsv->max_mas;
+	ai->max_interval = rsv->max_interval;
+
+
+	/* fill the not available vector from the available bm */
+	for (bit_index = 0; bit_index < UWB_NUM_MAS; bit_index++) {
+		if (!test_bit(bit_index, available->bm))
+			ai->bm[bit_index] = UWB_RSV_MAS_NOT_AVAIL;
+	}
+
+	if (ai->max_interval == 1) {
+		get_row_descriptors(ai);
+		if (uwb_rsv_find_best_row_alloc(ai) == UWB_RSV_ALLOC_FOUND)
+			goto alloc_found;
+		else
+			goto alloc_not_found;
+	}
+
+	get_column_descriptors(ai);
+        
+	for (interval = 16; interval >= 2; interval>>=1) {
+		if (interval > ai->max_interval)
+			continue;
+		if (uwb_rsv_find_best_col_alloc(ai, interval) == UWB_RSV_ALLOC_FOUND)
+			goto alloc_found;
+	}
+
+	/* try row reservation if no column is found */
+	get_row_descriptors(ai);
+	if (uwb_rsv_find_best_row_alloc(ai) == UWB_RSV_ALLOC_FOUND)
+		goto alloc_found;
+	else
+		goto alloc_not_found;
+
+  alloc_found:
+	bitmap_zero(result->bm, UWB_NUM_MAS);
+	bitmap_zero(result->unsafe_bm, UWB_NUM_MAS);
+	/* fill the safe and unsafe bitmaps */
+	for (bit_index = 0; bit_index < UWB_NUM_MAS; bit_index++) {
+		if (ai->bm[bit_index] == UWB_RSV_MAS_SAFE)
+			set_bit(bit_index, result->bm);
+		else if (ai->bm[bit_index] == UWB_RSV_MAS_UNSAFE)
+			set_bit(bit_index, result->unsafe_bm);
+	}
+	bitmap_or(result->bm, result->bm, result->unsafe_bm, UWB_NUM_MAS);
+
+	result->safe   = ai->safe_allocated_mases;
+	result->unsafe = ai->unsafe_allocated_mases;
+	
+	kfree(ai);		
+	return UWB_RSV_ALLOC_FOUND;
+  
+  alloc_not_found:
+	kfree(ai);
+	return UWB_RSV_ALLOC_NOT_FOUND;
+}

drivers/uwb/drp-avail.c

@@ -58,7 +58,7 @@ void uwb_drp_avail_init(struct uwb_rc *rc)
  *
  * avail = global & local & pending
  */
-static void uwb_drp_available(struct uwb_rc *rc, struct uwb_mas_bm *avail)
+void uwb_drp_available(struct uwb_rc *rc, struct uwb_mas_bm *avail)
 {
 	bitmap_and(avail->bm, rc->drp_avail.global, rc->drp_avail.local, UWB_NUM_MAS);
 	bitmap_and(avail->bm, avail->bm, rc->drp_avail.pending, UWB_NUM_MAS);
@@ -105,6 +105,7 @@ void uwb_drp_avail_release(struct uwb_rc *rc, struct uwb_mas_bm *mas)
 	bitmap_or(rc->drp_avail.local, rc->drp_avail.local, mas->bm, UWB_NUM_MAS);
 	bitmap_or(rc->drp_avail.pending, rc->drp_avail.pending, mas->bm, UWB_NUM_MAS);
 	rc->drp_avail.ie_valid = false;
+	uwb_rsv_handle_drp_avail_change(rc);
 }
 
 /**
@@ -280,6 +281,7 @@ int uwbd_evt_handle_rc_drp_avail(struct uwb_event *evt)
 	mutex_lock(&rc->rsvs_mutex);
 	bitmap_copy(rc->drp_avail.global, bmp, UWB_NUM_MAS);
 	rc->drp_avail.ie_valid = false;
+	uwb_rsv_handle_drp_avail_change(rc);
 	mutex_unlock(&rc->rsvs_mutex);
 
 	uwb_rsv_sched_update(rc);

drivers/uwb/drp-ie.c

@@ -22,6 +22,96 @@
 
 #include "uwb-internal.h"
 
+
+/*
+ * Return the reason code for a reservations's DRP IE.
+ */
+int uwb_rsv_reason_code(struct uwb_rsv *rsv)
+{
+	static const int reason_codes[] = {
+		[UWB_RSV_STATE_O_INITIATED]          = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_O_PENDING]            = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_O_MODIFIED]           = UWB_DRP_REASON_MODIFIED,
+		[UWB_RSV_STATE_O_ESTABLISHED]        = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_O_TO_BE_MOVED]        = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_O_MOVE_COMBINING]     = UWB_DRP_REASON_MODIFIED,
+		[UWB_RSV_STATE_O_MOVE_REDUCING]      = UWB_DRP_REASON_MODIFIED,
+		[UWB_RSV_STATE_O_MOVE_EXPANDING]     = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_T_ACCEPTED]           = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_T_CONFLICT]           = UWB_DRP_REASON_CONFLICT,
+		[UWB_RSV_STATE_T_PENDING]            = UWB_DRP_REASON_PENDING,
+		[UWB_RSV_STATE_T_DENIED]             = UWB_DRP_REASON_DENIED,
+		[UWB_RSV_STATE_T_RESIZED]            = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_T_EXPANDING_CONFLICT] = UWB_DRP_REASON_CONFLICT,
+		[UWB_RSV_STATE_T_EXPANDING_PENDING]  = UWB_DRP_REASON_PENDING,
+		[UWB_RSV_STATE_T_EXPANDING_DENIED]   = UWB_DRP_REASON_DENIED,
+	};
+
+	return reason_codes[rsv->state];
+}
+
+/*
+ * Return the reason code for a reservations's companion DRP IE .
+ */
+int uwb_rsv_companion_reason_code(struct uwb_rsv *rsv)
+{
+	static const int companion_reason_codes[] = {
+		[UWB_RSV_STATE_O_MOVE_EXPANDING]     = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = UWB_DRP_REASON_ACCEPTED,
+		[UWB_RSV_STATE_T_EXPANDING_CONFLICT] = UWB_DRP_REASON_CONFLICT,
+		[UWB_RSV_STATE_T_EXPANDING_PENDING]  = UWB_DRP_REASON_PENDING,
+		[UWB_RSV_STATE_T_EXPANDING_DENIED]   = UWB_DRP_REASON_DENIED,
+	};
+
+	return companion_reason_codes[rsv->state];
+}
+
+/*
+ * Return the status bit for a reservations's DRP IE.
+ */
+int uwb_rsv_status(struct uwb_rsv *rsv)
+{
+	static const int statuses[] = {
+		[UWB_RSV_STATE_O_INITIATED]          = 0,
+		[UWB_RSV_STATE_O_PENDING]            = 0,
+		[UWB_RSV_STATE_O_MODIFIED]           = 1,
+		[UWB_RSV_STATE_O_ESTABLISHED]        = 1,
+		[UWB_RSV_STATE_O_TO_BE_MOVED]        = 0,
+		[UWB_RSV_STATE_O_MOVE_COMBINING]     = 1,
+		[UWB_RSV_STATE_O_MOVE_REDUCING]      = 1,
+		[UWB_RSV_STATE_O_MOVE_EXPANDING]     = 1,
+		[UWB_RSV_STATE_T_ACCEPTED]           = 1,
+		[UWB_RSV_STATE_T_CONFLICT]           = 0,
+		[UWB_RSV_STATE_T_PENDING]            = 0,
+		[UWB_RSV_STATE_T_DENIED]             = 0,
+		[UWB_RSV_STATE_T_RESIZED]            = 1,
+		[UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = 1,
+		[UWB_RSV_STATE_T_EXPANDING_CONFLICT] = 1,
+		[UWB_RSV_STATE_T_EXPANDING_PENDING]  = 1,
+		[UWB_RSV_STATE_T_EXPANDING_DENIED]   = 1,
+
+	};
+
+	return statuses[rsv->state];
+}
+
+/*
+ * Return the status bit for a reservations's companion DRP IE .
+ */
+int uwb_rsv_companion_status(struct uwb_rsv *rsv)
+{
+	static const int companion_statuses[] = {
+		[UWB_RSV_STATE_O_MOVE_EXPANDING]     = 0,
+		[UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = 1,
+		[UWB_RSV_STATE_T_EXPANDING_CONFLICT] = 0,
+		[UWB_RSV_STATE_T_EXPANDING_PENDING]  = 0,
+		[UWB_RSV_STATE_T_EXPANDING_DENIED]   = 0,
+	};
+
+	return companion_statuses[rsv->state];
+}
+
 /*
  * Allocate a DRP IE.
  *
@@ -33,16 +123,12 @@
 static struct uwb_ie_drp *uwb_drp_ie_alloc(void)
 {
 	struct uwb_ie_drp *drp_ie;
-	unsigned tiebreaker;
 
 	drp_ie = kzalloc(sizeof(struct uwb_ie_drp) +
 			UWB_NUM_ZONES * sizeof(struct uwb_drp_alloc),
 			GFP_KERNEL);
 	if (drp_ie) {
 		drp_ie->hdr.element_id = UWB_IE_DRP;
-
-		get_random_bytes(&tiebreaker, sizeof(unsigned));
-		uwb_ie_drp_set_tiebreaker(drp_ie, tiebreaker & 1);
 	}
 	return drp_ie;
 }
@@ -103,43 +189,17 @@ static void uwb_drp_ie_from_bm(struct uwb_ie_drp *drp_ie,
  */
 int uwb_drp_ie_update(struct uwb_rsv *rsv)
 {
-	struct device *dev = &rsv->rc->uwb_dev.dev;
 	struct uwb_ie_drp *drp_ie;
-	int reason_code, status;
+	struct uwb_rsv_move *mv;
+	int unsafe;
 
-	switch (rsv->state) {
-	case UWB_RSV_STATE_NONE:
+	if (rsv->state == UWB_RSV_STATE_NONE) {
 		kfree(rsv->drp_ie);
 		rsv->drp_ie = NULL;
 		return 0;
-	case UWB_RSV_STATE_O_INITIATED:
-		reason_code = UWB_DRP_REASON_ACCEPTED;
-		status = 0;
-		break;
-	case UWB_RSV_STATE_O_PENDING:
-		reason_code = UWB_DRP_REASON_ACCEPTED;
-		status = 0;
-		break;
-	case UWB_RSV_STATE_O_MODIFIED:
-		reason_code = UWB_DRP_REASON_MODIFIED;
-		status = 1;
-		break;
-	case UWB_RSV_STATE_O_ESTABLISHED:
-		reason_code = UWB_DRP_REASON_ACCEPTED;
-		status = 1;
-		break;
-	case UWB_RSV_STATE_T_ACCEPTED:
-		reason_code = UWB_DRP_REASON_ACCEPTED;
-		status = 1;
-		break;
-	case UWB_RSV_STATE_T_DENIED:
-		reason_code = UWB_DRP_REASON_DENIED;
-		status = 0;
-		break;
-	default:
-		dev_dbg(dev, "rsv with unhandled state (%d)\n", rsv->state);
-		return -EINVAL;
 	}
+	
+	unsafe = rsv->mas.unsafe ? 1 : 0;
 
 	if (rsv->drp_ie == NULL) {
 		rsv->drp_ie = uwb_drp_ie_alloc();
@@ -148,9 +208,11 @@ int uwb_drp_ie_update(struct uwb_rsv *rsv)
 	}
 	drp_ie = rsv->drp_ie;
 
+	uwb_ie_drp_set_unsafe(drp_ie,       unsafe);
+	uwb_ie_drp_set_tiebreaker(drp_ie,   rsv->tiebreaker);
 	uwb_ie_drp_set_owner(drp_ie,        uwb_rsv_is_owner(rsv));
-	uwb_ie_drp_set_status(drp_ie,       status);
-	uwb_ie_drp_set_reason_code(drp_ie,  reason_code);
+	uwb_ie_drp_set_status(drp_ie,       uwb_rsv_status(rsv));
+	uwb_ie_drp_set_reason_code(drp_ie,  uwb_rsv_reason_code(rsv));
 	uwb_ie_drp_set_stream_index(drp_ie, rsv->stream);
 	uwb_ie_drp_set_type(drp_ie,         rsv->type);
 
@@ -168,6 +230,27 @@ int uwb_drp_ie_update(struct uwb_rsv *rsv)
 
 	uwb_drp_ie_from_bm(drp_ie, &rsv->mas);
 
+	if (uwb_rsv_has_two_drp_ies(rsv)) {
+		mv = &rsv->mv; 
+		if (mv->companion_drp_ie == NULL) {
+			mv->companion_drp_ie = uwb_drp_ie_alloc();
+			if (mv->companion_drp_ie == NULL)
+				return -ENOMEM;
+		}
+		drp_ie = mv->companion_drp_ie;
+		
+		/* keep all the same configuration of the main drp_ie */
+		memcpy(drp_ie, rsv->drp_ie, sizeof(struct uwb_ie_drp));
+		
+
+		/* FIXME: handle properly the unsafe bit */
+		uwb_ie_drp_set_unsafe(drp_ie,       1);
+		uwb_ie_drp_set_status(drp_ie,       uwb_rsv_companion_status(rsv));
+		uwb_ie_drp_set_reason_code(drp_ie,  uwb_rsv_companion_reason_code(rsv));
+	
+		uwb_drp_ie_from_bm(drp_ie, &mv->companion_mas);
+	}
+
 	rsv->ie_valid = true;
 	return 0;
 }
@@ -218,6 +301,8 @@ void uwb_drp_ie_to_bm(struct uwb_mas_bm *bm, const struct uwb_ie_drp *drp_ie)
 	u8 zone;
 	u16 zone_mask;
 
+	bitmap_zero(bm->bm, UWB_NUM_MAS);
+
 	for (cnt = 0; cnt < numallocs; cnt++) {
 		alloc = &drp_ie->allocs[cnt];
 		zone_bm = le16_to_cpu(alloc->zone_bm);
@@ -229,3 +314,4 @@ void uwb_drp_ie_to_bm(struct uwb_mas_bm *bm, const struct uwb_ie_drp *drp_ie)
 		}
 	}
 }
+

drivers/uwb/uwb-debug.c

@@ -82,29 +82,21 @@ struct uwb_dbg {
 	struct dentry *reservations_f;
 	struct dentry *accept_f;
 	struct dentry *drp_avail_f;
+	spinlock_t list_lock;
 };
 
 static struct dentry *root_dir;
 
 static void uwb_dbg_rsv_cb(struct uwb_rsv *rsv)
 {
-	struct uwb_rc *rc = rsv->rc;
-	struct device *dev = &rc->uwb_dev.dev;
-	struct uwb_dev_addr devaddr;
-	char owner[UWB_ADDR_STRSIZE], target[UWB_ADDR_STRSIZE];
+	struct uwb_dbg *dbg = rsv->pal_priv;
 
-	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, "debug: rsv %s -> %s: %s\n",
-		owner, target, uwb_rsv_state_str(rsv->state));
+	uwb_rsv_dump("debug", rsv);
 
 	if (rsv->state == UWB_RSV_STATE_NONE) {
+		spin_lock(&dbg->list_lock);
 		list_del(&rsv->pal_node);
+		spin_unlock(&dbg->list_lock);
 		uwb_rsv_destroy(rsv);
 	}
 }
@@ -128,20 +120,21 @@ static int cmd_rsv_establish(struct uwb_rc *rc,
 		return -ENOMEM;
 	}
 
-	rsv->owner       = &rc->uwb_dev;
-	rsv->target.type = UWB_RSV_TARGET_DEV;
-	rsv->target.dev  = target;
-	rsv->type        = cmd->type;
-	rsv->max_mas     = cmd->max_mas;
-	rsv->min_mas     = cmd->min_mas;
-	rsv->sparsity    = cmd->sparsity;
+	rsv->target.type  = UWB_RSV_TARGET_DEV;
+	rsv->target.dev   = target;
+	rsv->type         = cmd->type;
+	rsv->max_mas      = cmd->max_mas;
+	rsv->min_mas      = cmd->min_mas;
+	rsv->max_interval = cmd->max_interval;
 
 	ret = uwb_rsv_establish(rsv);
 	if (ret)
 		uwb_rsv_destroy(rsv);
-	else
+	else {
+		spin_lock(&(rc->dbg)->list_lock);
 		list_add_tail(&rsv->pal_node, &rc->dbg->rsvs);
-
+		spin_unlock(&(rc->dbg)->list_lock);
+	}
 	return ret;
 }
 
@@ -151,17 +144,24 @@ static int cmd_rsv_terminate(struct uwb_rc *rc,
 	struct uwb_rsv *rsv, *found = NULL;
 	int i = 0;
 
+	spin_lock(&(rc->dbg)->list_lock);
+
 	list_for_each_entry(rsv, &rc->dbg->rsvs, pal_node) {
 		if (i == cmd->index) {
 			found = rsv;
+			uwb_rsv_get(found);
 			break;
 		}
 		i++;
 	}
+
+	spin_unlock(&(rc->dbg)->list_lock);
+
 	if (!found)
 		return -EINVAL;
 
 	uwb_rsv_terminate(found);
+	uwb_rsv_put(found);
 
 	return 0;
 }
@@ -191,7 +191,7 @@ static ssize_t command_write(struct file *file, const char __user *buf,
 	struct uwb_rc *rc = file->private_data;
 	struct uwb_dbg_cmd cmd;
 	int ret = 0;
-
+	
 	if (len != sizeof(struct uwb_dbg_cmd))
 		return -EINVAL;
 
@@ -325,7 +325,9 @@ static void uwb_dbg_new_rsv(struct uwb_pal *pal, struct uwb_rsv *rsv)
 	struct uwb_dbg *dbg = container_of(pal, struct uwb_dbg, pal);
 
 	if (dbg->accept) {
+		spin_lock(&dbg->list_lock);
 		list_add_tail(&rsv->pal_node, &dbg->rsvs);
+		spin_unlock(&dbg->list_lock);
 		uwb_rsv_accept(rsv, uwb_dbg_rsv_cb, dbg);
 	}
 }
@@ -341,6 +343,7 @@ void uwb_dbg_add_rc(struct uwb_rc *rc)
 		return;
 
 	INIT_LIST_HEAD(&rc->dbg->rsvs);
+	spin_lock_init(&(rc->dbg)->list_lock);
 
 	uwb_pal_init(&rc->dbg->pal);
 	rc->dbg->pal.rc = rc;

drivers/uwb/uwb-internal.h

@@ -92,6 +92,12 @@ extern const char *uwb_rc_strerror(unsigned code);
 
 struct uwb_rc_neh;
 
+extern int uwb_rc_cmd_async(struct uwb_rc *rc, const char *cmd_name,
+			    struct uwb_rccb *cmd, size_t cmd_size,
+			    u8 expected_type, u16 expected_event,
+			    uwb_rc_cmd_cb_f cb, void *arg);
+
+
 void uwb_rc_neh_create(struct uwb_rc *rc);
 void uwb_rc_neh_destroy(struct uwb_rc *rc);
 
@@ -106,7 +112,69 @@ void uwb_rc_neh_put(struct uwb_rc_neh *neh);
 extern int uwb_est_create(void);
 extern void uwb_est_destroy(void);
 
+/*
+ * UWB conflicting alien reservations
+ */
+struct uwb_cnflt_alien {
+	struct uwb_rc *rc;
+	struct list_head rc_node;
+	struct uwb_mas_bm mas;
+	struct timer_list timer;
+	struct work_struct cnflt_update_work;
+};
 
+enum uwb_uwb_rsv_alloc_result {
+	UWB_RSV_ALLOC_FOUND = 0,
+	UWB_RSV_ALLOC_NOT_FOUND,
+};
+
+enum uwb_rsv_mas_status {
+	UWB_RSV_MAS_NOT_AVAIL = 1,
+	UWB_RSV_MAS_SAFE,
+	UWB_RSV_MAS_UNSAFE,
+};
+
+struct uwb_rsv_col_set_info {
+	unsigned char start_col;
+	unsigned char interval;
+	unsigned char safe_mas_per_col;
+	unsigned char unsafe_mas_per_col;
+};
+
+struct uwb_rsv_col_info {
+	unsigned char max_avail_safe;
+	unsigned char max_avail_unsafe;
+	unsigned char highest_mas[UWB_MAS_PER_ZONE];
+	struct uwb_rsv_col_set_info csi;
+};
+
+struct uwb_rsv_row_info {
+	unsigned char avail[UWB_MAS_PER_ZONE];
+	unsigned char free_rows;
+	unsigned char used_rows;
+};
+
+/*
+ * UWB find allocation
+ */
+struct uwb_rsv_alloc_info {
+	unsigned char bm[UWB_MAS_PER_ZONE * UWB_NUM_ZONES];
+	struct uwb_rsv_col_info ci[UWB_NUM_ZONES];
+	struct uwb_rsv_row_info ri;
+	struct uwb_mas_bm *not_available;
+	struct uwb_mas_bm *result;
+	int min_mas;
+	int max_mas;
+	int max_interval;
+	int total_allocated_mases;
+	int safe_allocated_mases;
+	int unsafe_allocated_mases;
+	int interval;
+};
+
+int uwb_rsv_find_best_allocation(struct uwb_rsv *rsv, struct uwb_mas_bm *available, 
+				 struct uwb_mas_bm *result);
+void uwb_rsv_handle_drp_avail_change(struct uwb_rc *rc);
 /*
  * UWB Events & management daemon
  */
@@ -254,18 +322,28 @@ void uwb_rsv_init(struct uwb_rc *rc);
 int uwb_rsv_setup(struct uwb_rc *rc);
 void uwb_rsv_cleanup(struct uwb_rc *rc);
 void uwb_rsv_remove_all(struct uwb_rc *rc);
+void uwb_rsv_get(struct uwb_rsv *rsv);
+void uwb_rsv_put(struct uwb_rsv *rsv);
+bool uwb_rsv_has_two_drp_ies(struct uwb_rsv *rsv);
+void uwb_rsv_dump(char *text, struct uwb_rsv *rsv);
+int uwb_rsv_try_move(struct uwb_rsv *rsv, struct uwb_mas_bm *available);
+void uwb_rsv_backoff_win_timer(unsigned long arg);
+void uwb_rsv_backoff_win_increment(struct uwb_rc *rc);
+int uwb_rsv_status(struct uwb_rsv *rsv);
+int uwb_rsv_companion_status(struct uwb_rsv *rsv);
 
 void uwb_rsv_set_state(struct uwb_rsv *rsv, enum uwb_rsv_state new_state);
 void uwb_rsv_remove(struct uwb_rsv *rsv);
 struct uwb_rsv *uwb_rsv_find(struct uwb_rc *rc, struct uwb_dev *src,
 			     struct uwb_ie_drp *drp_ie);
 void uwb_rsv_sched_update(struct uwb_rc *rc);
+void uwb_rsv_queue_update(struct uwb_rc *rc);
 
-void uwb_drp_handle_timeout(struct uwb_rsv *rsv);
 int uwb_drp_ie_update(struct uwb_rsv *rsv);
 void uwb_drp_ie_to_bm(struct uwb_mas_bm *bm, const struct uwb_ie_drp *drp_ie);
 
 void uwb_drp_avail_init(struct uwb_rc *rc);
+void uwb_drp_available(struct uwb_rc *rc, struct uwb_mas_bm *avail);
 int  uwb_drp_avail_reserve_pending(struct uwb_rc *rc, struct uwb_mas_bm *mas);
 void uwb_drp_avail_reserve(struct uwb_rc *rc, struct uwb_mas_bm *mas);
 void uwb_drp_avail_release(struct uwb_rc *rc, struct uwb_mas_bm *mas);

include/linux/uwb.h

@@ -67,6 +67,7 @@ struct uwb_dev {
 	struct uwb_dev_addr dev_addr;
 	int beacon_slot;
 	DECLARE_BITMAP(streams, UWB_NUM_STREAMS);
+	DECLARE_BITMAP(last_availability_bm, UWB_NUM_MAS);
 };
 #define to_uwb_dev(d) container_of(d, struct uwb_dev, dev)
 
@@ -109,6 +110,9 @@ struct uwbd {
  */
 struct uwb_mas_bm {
 	DECLARE_BITMAP(bm, UWB_NUM_MAS);
+	DECLARE_BITMAP(unsafe_bm, UWB_NUM_MAS);
+	int safe;
+	int unsafe;
 };
 
 /**
@@ -134,14 +138,24 @@ struct uwb_mas_bm {
  * FIXME: further target states TBD.
  */
 enum uwb_rsv_state {
-	UWB_RSV_STATE_NONE,
+	UWB_RSV_STATE_NONE = 0,
 	UWB_RSV_STATE_O_INITIATED,
 	UWB_RSV_STATE_O_PENDING,
 	UWB_RSV_STATE_O_MODIFIED,
 	UWB_RSV_STATE_O_ESTABLISHED,
+	UWB_RSV_STATE_O_TO_BE_MOVED,
+	UWB_RSV_STATE_O_MOVE_EXPANDING,
+	UWB_RSV_STATE_O_MOVE_COMBINING,
+	UWB_RSV_STATE_O_MOVE_REDUCING,
 	UWB_RSV_STATE_T_ACCEPTED,
 	UWB_RSV_STATE_T_DENIED,
+	UWB_RSV_STATE_T_CONFLICT,
 	UWB_RSV_STATE_T_PENDING,
+	UWB_RSV_STATE_T_EXPANDING_ACCEPTED,
+	UWB_RSV_STATE_T_EXPANDING_CONFLICT,
+	UWB_RSV_STATE_T_EXPANDING_PENDING,
+	UWB_RSV_STATE_T_EXPANDING_DENIED,
+	UWB_RSV_STATE_T_RESIZED,
 
 	UWB_RSV_STATE_LAST,
 };
@@ -166,6 +180,12 @@ struct uwb_rsv_target {
 	};
 };
 
+struct uwb_rsv_move {
+	struct uwb_mas_bm final_mas;
+	struct uwb_ie_drp *companion_drp_ie;
+	struct uwb_mas_bm companion_mas;
+};
+
 /*
  * Number of streams reserved for reservations targeted at DevAddrs.
  */
@@ -203,6 +223,7 @@ typedef void (*uwb_rsv_cb_f)(struct uwb_rsv *rsv);
  *
  * @status:         negotiation status
  * @stream:         stream index allocated for this reservation
+ * @tiebreaker:     conflict tiebreaker for this reservation
  * @mas:            reserved MAS
  * @drp_ie:         the DRP IE
  * @ie_valid:       true iff the DRP IE matches the reservation parameters
@@ -225,19 +246,22 @@ struct uwb_rsv {
 	enum uwb_drp_type type;
 	int max_mas;
 	int min_mas;
-	int sparsity;
+	int max_interval;
 	bool is_multicast;
 
 	uwb_rsv_cb_f callback;
 	void *pal_priv;
 
 	enum uwb_rsv_state state;
+	bool needs_release_companion_mas;
 	u8 stream;
+	u8 tiebreaker;
 	struct uwb_mas_bm mas;
 	struct uwb_ie_drp *drp_ie;
+	struct uwb_rsv_move mv;
 	bool ie_valid;
 	struct timer_list timer;
-	bool expired;
+	struct work_struct handle_timeout_work;
 };
 
 static const
@@ -279,6 +303,13 @@ struct uwb_drp_avail {
 	bool ie_valid;
 };
 
+struct uwb_drp_backoff_win {
+	u8 window;
+	u8 n;
+	int total_expired;
+	struct timer_list timer;
+	bool can_reserve_extra_mases;
+};
 
 const char *uwb_rsv_state_str(enum uwb_rsv_state state);
 const char *uwb_rsv_type_str(enum uwb_drp_type type);
@@ -294,6 +325,8 @@ void uwb_rsv_terminate(struct uwb_rsv *rsv);
 
 void uwb_rsv_accept(struct uwb_rsv *rsv, uwb_rsv_cb_f cb, void *pal_priv);
 
+void uwb_rsv_get_usable_mas(struct uwb_rsv *orig_rsv, struct uwb_mas_bm *mas);
+
 /**
  * Radio Control Interface instance
  *
@@ -364,12 +397,18 @@ struct uwb_rc {
 
 	struct uwbd uwbd;
 
+	struct uwb_drp_backoff_win bow;
 	struct uwb_drp_avail drp_avail;
 	struct list_head reservations;
+	struct list_head cnflt_alien_list;
+	struct uwb_mas_bm cnflt_alien_bitmap;
 	struct mutex rsvs_mutex;
+	spinlock_t rsvs_lock;
 	struct workqueue_struct *rsv_workq;
-	struct work_struct rsv_update_work;
 
+	struct delayed_work rsv_update_work;
+	struct delayed_work rsv_alien_bp_work;
+	int set_drp_ie_pending;
 	struct mutex ies_mutex;
 	struct uwb_rc_cmd_set_ie *ies;
 	size_t ies_capacity;

include/linux/uwb/debug-cmd.h

@@ -43,7 +43,7 @@ struct uwb_dbg_cmd_rsv_establish {
 	__u8  type;
 	__u16 max_mas;
 	__u16 min_mas;
-	__u8  sparsity;
+	__u8  max_interval;
 };
 
 struct uwb_dbg_cmd_rsv_terminate {

include/linux/uwb/spec.h

@@ -58,6 +58,11 @@ enum { UWB_NUM_ZONES = 16 };
  */
 #define UWB_MAS_PER_ZONE (UWB_NUM_MAS / UWB_NUM_ZONES)
 
+/*
+ * Number of MAS required before a row can be considered available.
+ */
+#define UWB_USABLE_MAS_PER_ROW (UWB_NUM_ZONES - 1)
+
 /*
  * Number of streams per DRP reservation between a pair of devices.
  *
@@ -93,6 +98,26 @@ enum { UWB_BEACON_SLOT_LENGTH_US = 85 };
  */
 enum { UWB_MAX_LOST_BEACONS = 3 };
 
+/*
+ * mDRPBackOffWinMin
+ *
+ * The minimum number of superframes to wait before trying to reserve
+ * extra MAS.
+ *
+ * [ECMA-368] section 17.16
+ */
+enum { UWB_DRP_BACKOFF_WIN_MIN = 2 };
+
+/*
+ * mDRPBackOffWinMax
+ *
+ * The maximum number of superframes to wait before trying to reserve
+ * extra MAS.
+ *
+ * [ECMA-368] section 17.16
+ */
+enum { UWB_DRP_BACKOFF_WIN_MAX = 16 };
+
 /*
  * Length of a superframe in microseconds.
  */