uwb: add the UWB stack (reservation manager)

DRP and reservation management.

Signed-off-by: David Vrabel <david.vrabel@csr.com>

1 files changed, 232 insertions, 0 deletions

diff --git a/drivers/uwb/drp-ie.c b/drivers/uwb/drp-ie.c
new file mode 100644
index 0000000..882724c
--- /dev/null
+++ b/drivers/uwb/drp-ie.c
@@ -0,0 +1,232 @@
+/*
+ * UWB DRP IE management.
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * 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/random.h>
+#include <linux/uwb.h>
+
+#include "uwb-internal.h"
+
+/*
+ * Allocate a DRP IE.
+ *
+ * To save having to free/allocate a DRP IE when its MAS changes,
+ * enough memory is allocated for the maxiumum number of DRP
+ * allocation fields.  This gives an overhead per reservation of up to
+ * (UWB_NUM_ZONES - 1) * 4 = 60 octets.
+ */
+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;
+}
+
+
+/*
+ * Fill a DRP IE's allocation fields from a MAS bitmap.
+ */
+static void uwb_drp_ie_from_bm(struct uwb_ie_drp *drp_ie,
+			       struct uwb_mas_bm *mas)
+{
+	int z, i, num_fields = 0, next = 0;
+	struct uwb_drp_alloc *zones;
+	__le16 current_bmp;
+	DECLARE_BITMAP(tmp_bmp, UWB_NUM_MAS);
+	DECLARE_BITMAP(tmp_mas_bm, UWB_MAS_PER_ZONE);
+
+	zones = drp_ie->allocs;
+
+	bitmap_copy(tmp_bmp, mas->bm, UWB_NUM_MAS);
+
+	/* Determine unique MAS bitmaps in zones from bitmap. */
+	for (z = 0; z < UWB_NUM_ZONES; z++) {
+		bitmap_copy(tmp_mas_bm, tmp_bmp, UWB_MAS_PER_ZONE);
+		if (bitmap_weight(tmp_mas_bm, UWB_MAS_PER_ZONE) > 0) {
+			bool found = false;
+			current_bmp = (__le16) *tmp_mas_bm;
+			for (i = 0; i < next; i++) {
+				if (current_bmp == zones[i].mas_bm) {
+					zones[i].zone_bm |= 1 << z;
+					found = true;
+					break;
+				}
+			}
+			if (!found)  {
+				num_fields++;
+				zones[next].zone_bm = 1 << z;
+				zones[next].mas_bm = current_bmp;
+				next++;
+			}
+		}
+		bitmap_shift_right(tmp_bmp, tmp_bmp, UWB_MAS_PER_ZONE, UWB_NUM_MAS);
+	}
+
+	/* Store in format ready for transmission (le16). */
+	for (i = 0; i < num_fields; i++) {
+		drp_ie->allocs[i].zone_bm = cpu_to_le16(zones[i].zone_bm);
+		drp_ie->allocs[i].mas_bm = cpu_to_le16(zones[i].mas_bm);
+	}
+
+	drp_ie->hdr.length = sizeof(struct uwb_ie_drp) - sizeof(struct uwb_ie_hdr)
+		+ num_fields * sizeof(struct uwb_drp_alloc);
+}
+
+/**
+ * uwb_drp_ie_update - update a reservation's DRP IE
+ * @rsv: the reservation
+ */
+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;
+
+	switch (rsv->state) {
+	case 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;
+	}
+
+	if (rsv->drp_ie == NULL) {
+		rsv->drp_ie = uwb_drp_ie_alloc();
+		if (rsv->drp_ie == NULL)
+			return -ENOMEM;
+	}
+	drp_ie = rsv->drp_ie;
+
+	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_stream_index(drp_ie, rsv->stream);
+	uwb_ie_drp_set_type(drp_ie,         rsv->type);
+
+	if (uwb_rsv_is_owner(rsv)) {
+		switch (rsv->target.type) {
+		case UWB_RSV_TARGET_DEV:
+			drp_ie->dev_addr = rsv->target.dev->dev_addr;
+			break;
+		case UWB_RSV_TARGET_DEVADDR:
+			drp_ie->dev_addr = rsv->target.devaddr;
+			break;
+		}
+	} else
+		drp_ie->dev_addr = rsv->owner->dev_addr;
+
+	uwb_drp_ie_from_bm(drp_ie, &rsv->mas);
+
+	rsv->ie_valid = true;
+	return 0;
+}
+
+/*
+ * Set MAS bits from given MAS bitmap in a single zone of large bitmap.
+ *
+ * We are given a zone id and the MAS bitmap of bits that need to be set in
+ * this zone. Note that this zone may already have bits set and this only
+ * adds settings - we cannot simply assign the MAS bitmap contents to the
+ * zone contents. We iterate over the the bits (MAS) in the zone and set the
+ * bits that are set in the given MAS bitmap.
+ */
+static
+void uwb_drp_ie_single_zone_to_bm(struct uwb_mas_bm *bm, u8 zone, u16 mas_bm)
+{
+	int mas;
+	u16 mas_mask;
+
+	for (mas = 0; mas < UWB_MAS_PER_ZONE; mas++) {
+		mas_mask = 1 << mas;
+		if (mas_bm & mas_mask)
+			set_bit(zone * UWB_NUM_ZONES + mas, bm->bm);
+	}
+}
+
+/**
+ * uwb_drp_ie_zones_to_bm - convert DRP allocation fields to a bitmap
+ * @mas:    MAS bitmap that will be populated to correspond to the
+ *          allocation fields in the DRP IE
+ * @drp_ie: the DRP IE that contains the allocation fields.
+ *
+ * The input format is an array of MAS allocation fields (16 bit Zone
+ * bitmap, 16 bit MAS bitmap) as described in [ECMA-368] section
+ * 16.8.6. The output is a full 256 bit MAS bitmap.
+ *
+ * We go over all the allocation fields, for each allocation field we
+ * know which zones are impacted. We iterate over all the zones
+ * impacted and call a function that will set the correct MAS bits in
+ * each zone.
+ */
+void uwb_drp_ie_to_bm(struct uwb_mas_bm *bm, const struct uwb_ie_drp *drp_ie)
+{
+	int numallocs = (drp_ie->hdr.length - 4) / 4;
+	const struct uwb_drp_alloc *alloc;
+	int cnt;
+	u16 zone_bm, mas_bm;
+	u8 zone;
+	u16 zone_mask;
+
+	for (cnt = 0; cnt < numallocs; cnt++) {
+		alloc = &drp_ie->allocs[cnt];
+		zone_bm = le16_to_cpu(alloc->zone_bm);
+		mas_bm = le16_to_cpu(alloc->mas_bm);
+		for (zone = 0; zone < UWB_NUM_ZONES; zone++)   {
+			zone_mask = 1 << zone;
+			if (zone_bm & zone_mask)
+				uwb_drp_ie_single_zone_to_bm(bm, zone, mas_bm);
+		}
+	}
+}