/* * 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); } } }