/*
* 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);
}
}
}
