drivers/uwb/drp-ie.c

   1 /*
   2  * UWB DRP IE management.
   3  *
   4  * Copyright (C) 2005-2006 Intel Corporation
   5  * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License version
   9  * 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #include <linux/kernel.h>
  20 #include <linux/random.h>
  21 #include <linux/slab.h>
  22 #include <linux/uwb.h>
  23
  24 #include "uwb-internal.h"
  25
  26
  27 /*
  28  * Return the reason code for a reservations's DRP IE.
  29  */
  30 static int uwb_rsv_reason_code(struct uwb_rsv *rsv)
  31 {
  32         static const int reason_codes[] = {
  33                 [UWB_RSV_STATE_O_INITIATED]          = UWB_DRP_REASON_ACCEPTED,
  34                 [UWB_RSV_STATE_O_PENDING]            = UWB_DRP_REASON_ACCEPTED,
  35                 [UWB_RSV_STATE_O_MODIFIED]           = UWB_DRP_REASON_MODIFIED,
  36                 [UWB_RSV_STATE_O_ESTABLISHED]        = UWB_DRP_REASON_ACCEPTED,
  37                 [UWB_RSV_STATE_O_TO_BE_MOVED]        = UWB_DRP_REASON_ACCEPTED,
  38                 [UWB_RSV_STATE_O_MOVE_COMBINING]     = UWB_DRP_REASON_MODIFIED,
  39                 [UWB_RSV_STATE_O_MOVE_REDUCING]      = UWB_DRP_REASON_MODIFIED,
  40                 [UWB_RSV_STATE_O_MOVE_EXPANDING]     = UWB_DRP_REASON_ACCEPTED,
  41                 [UWB_RSV_STATE_T_ACCEPTED]           = UWB_DRP_REASON_ACCEPTED,
  42                 [UWB_RSV_STATE_T_CONFLICT]           = UWB_DRP_REASON_CONFLICT,
  43                 [UWB_RSV_STATE_T_PENDING]            = UWB_DRP_REASON_PENDING,
  44                 [UWB_RSV_STATE_T_DENIED]             = UWB_DRP_REASON_DENIED,
  45                 [UWB_RSV_STATE_T_RESIZED]            = UWB_DRP_REASON_ACCEPTED,
  46                 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = UWB_DRP_REASON_ACCEPTED,
  47                 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = UWB_DRP_REASON_CONFLICT,
  48                 [UWB_RSV_STATE_T_EXPANDING_PENDING]  = UWB_DRP_REASON_PENDING,
  49                 [UWB_RSV_STATE_T_EXPANDING_DENIED]   = UWB_DRP_REASON_DENIED,
  50         };
  51
  52         return reason_codes[rsv->state];
  53 }
  54
  55 /*
  56  * Return the reason code for a reservations's companion DRP IE .
  57  */
  58 static int uwb_rsv_companion_reason_code(struct uwb_rsv *rsv)
  59 {
  60         static const int companion_reason_codes[] = {
  61                 [UWB_RSV_STATE_O_MOVE_EXPANDING]     = UWB_DRP_REASON_ACCEPTED,
  62                 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = UWB_DRP_REASON_ACCEPTED,
  63                 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = UWB_DRP_REASON_CONFLICT,
  64                 [UWB_RSV_STATE_T_EXPANDING_PENDING]  = UWB_DRP_REASON_PENDING,
  65                 [UWB_RSV_STATE_T_EXPANDING_DENIED]   = UWB_DRP_REASON_DENIED,
  66         };
  67
  68         return companion_reason_codes[rsv->state];
  69 }
  70
  71 /*
  72  * Return the status bit for a reservations's DRP IE.
  73  */
  74 int uwb_rsv_status(struct uwb_rsv *rsv)
  75 {
  76         static const int statuses[] = {
  77                 [UWB_RSV_STATE_O_INITIATED]          = 0,
  78                 [UWB_RSV_STATE_O_PENDING]            = 0,
  79                 [UWB_RSV_STATE_O_MODIFIED]           = 1,
  80                 [UWB_RSV_STATE_O_ESTABLISHED]        = 1,
  81                 [UWB_RSV_STATE_O_TO_BE_MOVED]        = 0,
  82                 [UWB_RSV_STATE_O_MOVE_COMBINING]     = 1,
  83                 [UWB_RSV_STATE_O_MOVE_REDUCING]      = 1,
  84                 [UWB_RSV_STATE_O_MOVE_EXPANDING]     = 1,
  85                 [UWB_RSV_STATE_T_ACCEPTED]           = 1,
  86                 [UWB_RSV_STATE_T_CONFLICT]           = 0,
  87                 [UWB_RSV_STATE_T_PENDING]            = 0,
  88                 [UWB_RSV_STATE_T_DENIED]             = 0,
  89                 [UWB_RSV_STATE_T_RESIZED]            = 1,
  90                 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = 1,
  91                 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = 1,
  92                 [UWB_RSV_STATE_T_EXPANDING_PENDING]  = 1,
  93                 [UWB_RSV_STATE_T_EXPANDING_DENIED]   = 1,
  94
  95         };
  96
  97         return statuses[rsv->state];
  98 }
  99
 100 /*
 101  * Return the status bit for a reservations's companion DRP IE .
 102  */
 103 int uwb_rsv_companion_status(struct uwb_rsv *rsv)
 104 {
 105         static const int companion_statuses[] = {
 106                 [UWB_RSV_STATE_O_MOVE_EXPANDING]     = 0,
 107                 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = 1,
 108                 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = 0,
 109                 [UWB_RSV_STATE_T_EXPANDING_PENDING]  = 0,
 110                 [UWB_RSV_STATE_T_EXPANDING_DENIED]   = 0,
 111         };
 112
 113         return companion_statuses[rsv->state];
 114 }
 115
 116 /*
 117  * Allocate a DRP IE.
 118  *
 119  * To save having to free/allocate a DRP IE when its MAS changes,
 120  * enough memory is allocated for the maxiumum number of DRP
 121  * allocation fields.  This gives an overhead per reservation of up to
 122  * (UWB_NUM_ZONES - 1) * 4 = 60 octets.
 123  */
 124 static struct uwb_ie_drp *uwb_drp_ie_alloc(void)
 125 {
 126         struct uwb_ie_drp *drp_ie;
 127
 128         drp_ie = kzalloc(struct_size(drp_ie, allocs, UWB_NUM_ZONES),
 129                          GFP_KERNEL);
 130         if (drp_ie)
 131                 drp_ie->hdr.element_id = UWB_IE_DRP;
 132         return drp_ie;
 133 }
 134
 135
 136 /*
 137  * Fill a DRP IE's allocation fields from a MAS bitmap.
 138  */
 139 static void uwb_drp_ie_from_bm(struct uwb_ie_drp *drp_ie,
 140                                struct uwb_mas_bm *mas)
 141 {
 142         int z, i, num_fields = 0, next = 0;
 143         struct uwb_drp_alloc *zones;
 144         __le16 current_bmp;
 145         DECLARE_BITMAP(tmp_bmp, UWB_NUM_MAS);
 146         DECLARE_BITMAP(tmp_mas_bm, UWB_MAS_PER_ZONE);
 147
 148         zones = drp_ie->allocs;
 149
 150         bitmap_copy(tmp_bmp, mas->bm, UWB_NUM_MAS);
 151
 152         /* Determine unique MAS bitmaps in zones from bitmap. */
 153         for (z = 0; z < UWB_NUM_ZONES; z++) {
 154                 bitmap_copy(tmp_mas_bm, tmp_bmp, UWB_MAS_PER_ZONE);
 155                 if (bitmap_weight(tmp_mas_bm, UWB_MAS_PER_ZONE) > 0) {
 156                         bool found = false;
 157                         current_bmp = (__le16) *tmp_mas_bm;
 158                         for (i = 0; i < next; i++) {
 159                                 if (current_bmp == zones[i].mas_bm) {
 160                                         zones[i].zone_bm |= 1 << z;
 161                                         found = true;
 162                                         break;
 163                                 }
 164                         }
 165                         if (!found)  {
 166                                 num_fields++;
 167                                 zones[next].zone_bm = 1 << z;
 168                                 zones[next].mas_bm = current_bmp;
 169                                 next++;
 170                         }
 171                 }
 172                 bitmap_shift_right(tmp_bmp, tmp_bmp, UWB_MAS_PER_ZONE, UWB_NUM_MAS);
 173         }
 174
 175         /* Store in format ready for transmission (le16). */
 176         for (i = 0; i < num_fields; i++) {
 177                 drp_ie->allocs[i].zone_bm = cpu_to_le16(zones[i].zone_bm);
 178                 drp_ie->allocs[i].mas_bm = cpu_to_le16(zones[i].mas_bm);
 179         }
 180
 181         drp_ie->hdr.length = sizeof(struct uwb_ie_drp) - sizeof(struct uwb_ie_hdr)
 182                 + num_fields * sizeof(struct uwb_drp_alloc);
 183 }
 184
 185 /**
 186  * uwb_drp_ie_update - update a reservation's DRP IE
 187  * @rsv: the reservation
 188  */
 189 int uwb_drp_ie_update(struct uwb_rsv *rsv)
 190 {
 191         struct uwb_ie_drp *drp_ie;
 192         struct uwb_rsv_move *mv;
 193         int unsafe;
 194
 195         if (rsv->state == UWB_RSV_STATE_NONE) {
 196                 kfree(rsv->drp_ie);
 197                 rsv->drp_ie = NULL;
 198                 return 0;
 199         }
 200
 201         unsafe = rsv->mas.unsafe ? 1 : 0;
 202
 203         if (rsv->drp_ie == NULL) {
 204                 rsv->drp_ie = uwb_drp_ie_alloc();
 205                 if (rsv->drp_ie == NULL)
 206                         return -ENOMEM;
 207         }
 208         drp_ie = rsv->drp_ie;
 209
 210         uwb_ie_drp_set_unsafe(drp_ie,       unsafe);
 211         uwb_ie_drp_set_tiebreaker(drp_ie,   rsv->tiebreaker);
 212         uwb_ie_drp_set_owner(drp_ie,        uwb_rsv_is_owner(rsv));
 213         uwb_ie_drp_set_status(drp_ie,       uwb_rsv_status(rsv));
 214         uwb_ie_drp_set_reason_code(drp_ie,  uwb_rsv_reason_code(rsv));
 215         uwb_ie_drp_set_stream_index(drp_ie, rsv->stream);
 216         uwb_ie_drp_set_type(drp_ie,         rsv->type);
 217
 218         if (uwb_rsv_is_owner(rsv)) {
 219                 switch (rsv->target.type) {
 220                 case UWB_RSV_TARGET_DEV:
 221                         drp_ie->dev_addr = rsv->target.dev->dev_addr;
 222                         break;
 223                 case UWB_RSV_TARGET_DEVADDR:
 224                         drp_ie->dev_addr = rsv->target.devaddr;
 225                         break;
 226                 }
 227         } else
 228                 drp_ie->dev_addr = rsv->owner->dev_addr;
 229
 230         uwb_drp_ie_from_bm(drp_ie, &rsv->mas);
 231
 232         if (uwb_rsv_has_two_drp_ies(rsv)) {
 233                 mv = &rsv->mv;
 234                 if (mv->companion_drp_ie == NULL) {
 235                         mv->companion_drp_ie = uwb_drp_ie_alloc();
 236                         if (mv->companion_drp_ie == NULL)
 237                                 return -ENOMEM;
 238                 }
 239                 drp_ie = mv->companion_drp_ie;
 240
 241                 /* keep all the same configuration of the main drp_ie */
 242                 memcpy(drp_ie, rsv->drp_ie, sizeof(struct uwb_ie_drp));
 243
 244
 245                 /* FIXME: handle properly the unsafe bit */
 246                 uwb_ie_drp_set_unsafe(drp_ie,       1);
 247                 uwb_ie_drp_set_status(drp_ie,       uwb_rsv_companion_status(rsv));
 248                 uwb_ie_drp_set_reason_code(drp_ie,  uwb_rsv_companion_reason_code(rsv));
 249
 250                 uwb_drp_ie_from_bm(drp_ie, &mv->companion_mas);
 251         }
 252
 253         rsv->ie_valid = true;
 254         return 0;
 255 }
 256
 257 /*
 258  * Set MAS bits from given MAS bitmap in a single zone of large bitmap.
 259  *
 260  * We are given a zone id and the MAS bitmap of bits that need to be set in
 261  * this zone. Note that this zone may already have bits set and this only
 262  * adds settings - we cannot simply assign the MAS bitmap contents to the
 263  * zone contents. We iterate over the the bits (MAS) in the zone and set the
 264  * bits that are set in the given MAS bitmap.
 265  */
 266 static
 267 void uwb_drp_ie_single_zone_to_bm(struct uwb_mas_bm *bm, u8 zone, u16 mas_bm)
 268 {
 269         int mas;
 270         u16 mas_mask;
 271
 272         for (mas = 0; mas < UWB_MAS_PER_ZONE; mas++) {
 273                 mas_mask = 1 << mas;
 274                 if (mas_bm & mas_mask)
 275                         set_bit(zone * UWB_NUM_ZONES + mas, bm->bm);
 276         }
 277 }
 278
 279 /**
 280  * uwb_drp_ie_zones_to_bm - convert DRP allocation fields to a bitmap
 281  * @mas:    MAS bitmap that will be populated to correspond to the
 282  *          allocation fields in the DRP IE
 283  * @drp_ie: the DRP IE that contains the allocation fields.
 284  *
 285  * The input format is an array of MAS allocation fields (16 bit Zone
 286  * bitmap, 16 bit MAS bitmap) as described in [ECMA-368] section
 287  * 16.8.6. The output is a full 256 bit MAS bitmap.
 288  *
 289  * We go over all the allocation fields, for each allocation field we
 290  * know which zones are impacted. We iterate over all the zones
 291  * impacted and call a function that will set the correct MAS bits in
 292  * each zone.
 293  */
 294 void uwb_drp_ie_to_bm(struct uwb_mas_bm *bm, const struct uwb_ie_drp *drp_ie)
 295 {
 296         int numallocs = (drp_ie->hdr.length - 4) / 4;
 297         const struct uwb_drp_alloc *alloc;
 298         int cnt;
 299         u16 zone_bm, mas_bm;
 300         u8 zone;
 301         u16 zone_mask;
 302
 303         bitmap_zero(bm->bm, UWB_NUM_MAS);
 304
 305         for (cnt = 0; cnt < numallocs; cnt++) {
 306                 alloc = &drp_ie->allocs[cnt];
 307                 zone_bm = le16_to_cpu(alloc->zone_bm);
 308                 mas_bm = le16_to_cpu(alloc->mas_bm);
 309                 for (zone = 0; zone < UWB_NUM_ZONES; zone++)   {
 310                         zone_mask = 1 << zone;
 311                         if (zone_bm & zone_mask)
 312                                 uwb_drp_ie_single_zone_to_bm(bm, zone, mas_bm);
 313                 }
 314         }
 315 }
 316