drivers/uwb/drp-ie.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * UWB DRP IE management.
   4  *
   5  * Copyright (C) 2005-2006 Intel Corporation
   6  * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/random.h>
  10 #include <linux/slab.h>
  11 #include <linux/uwb.h>
  12
  13 #include "uwb-internal.h"
  14
  15
  16 /*
  17  * Return the reason code for a reservations's DRP IE.
  18  */
  19 static int uwb_rsv_reason_code(struct uwb_rsv *rsv)
  20 {
  21         static const int reason_codes[] = {
  22                 [UWB_RSV_STATE_O_INITIATED]          = UWB_DRP_REASON_ACCEPTED,
  23                 [UWB_RSV_STATE_O_PENDING]            = UWB_DRP_REASON_ACCEPTED,
  24                 [UWB_RSV_STATE_O_MODIFIED]           = UWB_DRP_REASON_MODIFIED,
  25                 [UWB_RSV_STATE_O_ESTABLISHED]        = UWB_DRP_REASON_ACCEPTED,
  26                 [UWB_RSV_STATE_O_TO_BE_MOVED]        = UWB_DRP_REASON_ACCEPTED,
  27                 [UWB_RSV_STATE_O_MOVE_COMBINING]     = UWB_DRP_REASON_MODIFIED,
  28                 [UWB_RSV_STATE_O_MOVE_REDUCING]      = UWB_DRP_REASON_MODIFIED,
  29                 [UWB_RSV_STATE_O_MOVE_EXPANDING]     = UWB_DRP_REASON_ACCEPTED,
  30                 [UWB_RSV_STATE_T_ACCEPTED]           = UWB_DRP_REASON_ACCEPTED,
  31                 [UWB_RSV_STATE_T_CONFLICT]           = UWB_DRP_REASON_CONFLICT,
  32                 [UWB_RSV_STATE_T_PENDING]            = UWB_DRP_REASON_PENDING,
  33                 [UWB_RSV_STATE_T_DENIED]             = UWB_DRP_REASON_DENIED,
  34                 [UWB_RSV_STATE_T_RESIZED]            = UWB_DRP_REASON_ACCEPTED,
  35                 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = UWB_DRP_REASON_ACCEPTED,
  36                 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = UWB_DRP_REASON_CONFLICT,
  37                 [UWB_RSV_STATE_T_EXPANDING_PENDING]  = UWB_DRP_REASON_PENDING,
  38                 [UWB_RSV_STATE_T_EXPANDING_DENIED]   = UWB_DRP_REASON_DENIED,
  39         };
  40
  41         return reason_codes[rsv->state];
  42 }
  43
  44 /*
  45  * Return the reason code for a reservations's companion DRP IE .
  46  */
  47 static int uwb_rsv_companion_reason_code(struct uwb_rsv *rsv)
  48 {
  49         static const int companion_reason_codes[] = {
  50                 [UWB_RSV_STATE_O_MOVE_EXPANDING]     = UWB_DRP_REASON_ACCEPTED,
  51                 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = UWB_DRP_REASON_ACCEPTED,
  52                 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = UWB_DRP_REASON_CONFLICT,
  53                 [UWB_RSV_STATE_T_EXPANDING_PENDING]  = UWB_DRP_REASON_PENDING,
  54                 [UWB_RSV_STATE_T_EXPANDING_DENIED]   = UWB_DRP_REASON_DENIED,
  55         };
  56
  57         return companion_reason_codes[rsv->state];
  58 }
  59
  60 /*
  61  * Return the status bit for a reservations's DRP IE.
  62  */
  63 int uwb_rsv_status(struct uwb_rsv *rsv)
  64 {
  65         static const int statuses[] = {
  66                 [UWB_RSV_STATE_O_INITIATED]          = 0,
  67                 [UWB_RSV_STATE_O_PENDING]            = 0,
  68                 [UWB_RSV_STATE_O_MODIFIED]           = 1,
  69                 [UWB_RSV_STATE_O_ESTABLISHED]        = 1,
  70                 [UWB_RSV_STATE_O_TO_BE_MOVED]        = 0,
  71                 [UWB_RSV_STATE_O_MOVE_COMBINING]     = 1,
  72                 [UWB_RSV_STATE_O_MOVE_REDUCING]      = 1,
  73                 [UWB_RSV_STATE_O_MOVE_EXPANDING]     = 1,
  74                 [UWB_RSV_STATE_T_ACCEPTED]           = 1,
  75                 [UWB_RSV_STATE_T_CONFLICT]           = 0,
  76                 [UWB_RSV_STATE_T_PENDING]            = 0,
  77                 [UWB_RSV_STATE_T_DENIED]             = 0,
  78                 [UWB_RSV_STATE_T_RESIZED]            = 1,
  79                 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = 1,
  80                 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = 1,
  81                 [UWB_RSV_STATE_T_EXPANDING_PENDING]  = 1,
  82                 [UWB_RSV_STATE_T_EXPANDING_DENIED]   = 1,
  83
  84         };
  85
  86         return statuses[rsv->state];
  87 }
  88
  89 /*
  90  * Return the status bit for a reservations's companion DRP IE .
  91  */
  92 int uwb_rsv_companion_status(struct uwb_rsv *rsv)
  93 {
  94         static const int companion_statuses[] = {
  95                 [UWB_RSV_STATE_O_MOVE_EXPANDING]     = 0,
  96                 [UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = 1,
  97                 [UWB_RSV_STATE_T_EXPANDING_CONFLICT] = 0,
  98                 [UWB_RSV_STATE_T_EXPANDING_PENDING]  = 0,
  99                 [UWB_RSV_STATE_T_EXPANDING_DENIED]   = 0,
 100         };
 101
 102         return companion_statuses[rsv->state];
 103 }
 104
 105 /*
 106  * Allocate a DRP IE.
 107  *
 108  * To save having to free/allocate a DRP IE when its MAS changes,
 109  * enough memory is allocated for the maxiumum number of DRP
 110  * allocation fields.  This gives an overhead per reservation of up to
 111  * (UWB_NUM_ZONES - 1) * 4 = 60 octets.
 112  */
 113 static struct uwb_ie_drp *uwb_drp_ie_alloc(void)
 114 {
 115         struct uwb_ie_drp *drp_ie;
 116
 117         drp_ie = kzalloc(struct_size(drp_ie, allocs, UWB_NUM_ZONES),
 118                          GFP_KERNEL);
 119         if (drp_ie)
 120                 drp_ie->hdr.element_id = UWB_IE_DRP;
 121         return drp_ie;
 122 }
 123
 124
 125 /*
 126  * Fill a DRP IE's allocation fields from a MAS bitmap.
 127  */
 128 static void uwb_drp_ie_from_bm(struct uwb_ie_drp *drp_ie,
 129                                struct uwb_mas_bm *mas)
 130 {
 131         int z, i, num_fields = 0, next = 0;
 132         struct uwb_drp_alloc *zones;
 133         __le16 current_bmp;
 134         DECLARE_BITMAP(tmp_bmp, UWB_NUM_MAS);
 135         DECLARE_BITMAP(tmp_mas_bm, UWB_MAS_PER_ZONE);
 136
 137         zones = drp_ie->allocs;
 138
 139         bitmap_copy(tmp_bmp, mas->bm, UWB_NUM_MAS);
 140
 141         /* Determine unique MAS bitmaps in zones from bitmap. */
 142         for (z = 0; z < UWB_NUM_ZONES; z++) {
 143                 bitmap_copy(tmp_mas_bm, tmp_bmp, UWB_MAS_PER_ZONE);
 144                 if (bitmap_weight(tmp_mas_bm, UWB_MAS_PER_ZONE) > 0) {
 145                         bool found = false;
 146                         current_bmp = (__le16) *tmp_mas_bm;
 147                         for (i = 0; i < next; i++) {
 148                                 if (current_bmp == zones[i].mas_bm) {
 149                                         zones[i].zone_bm |= 1 << z;
 150                                         found = true;
 151                                         break;
 152                                 }
 153                         }
 154                         if (!found)  {
 155                                 num_fields++;
 156                                 zones[next].zone_bm = 1 << z;
 157                                 zones[next].mas_bm = current_bmp;
 158                                 next++;
 159                         }
 160                 }
 161                 bitmap_shift_right(tmp_bmp, tmp_bmp, UWB_MAS_PER_ZONE, UWB_NUM_MAS);
 162         }
 163
 164         /* Store in format ready for transmission (le16). */
 165         for (i = 0; i < num_fields; i++) {
 166                 drp_ie->allocs[i].zone_bm = cpu_to_le16(zones[i].zone_bm);
 167                 drp_ie->allocs[i].mas_bm = cpu_to_le16(zones[i].mas_bm);
 168         }
 169
 170         drp_ie->hdr.length = sizeof(struct uwb_ie_drp) - sizeof(struct uwb_ie_hdr)
 171                 + num_fields * sizeof(struct uwb_drp_alloc);
 172 }
 173
 174 /**
 175  * uwb_drp_ie_update - update a reservation's DRP IE
 176  * @rsv: the reservation
 177  */
 178 int uwb_drp_ie_update(struct uwb_rsv *rsv)
 179 {
 180         struct uwb_ie_drp *drp_ie;
 181         struct uwb_rsv_move *mv;
 182         int unsafe;
 183
 184         if (rsv->state == UWB_RSV_STATE_NONE) {
 185                 kfree(rsv->drp_ie);
 186                 rsv->drp_ie = NULL;
 187                 return 0;
 188         }
 189
 190         unsafe = rsv->mas.unsafe ? 1 : 0;
 191
 192         if (rsv->drp_ie == NULL) {
 193                 rsv->drp_ie = uwb_drp_ie_alloc();
 194                 if (rsv->drp_ie == NULL)
 195                         return -ENOMEM;
 196         }
 197         drp_ie = rsv->drp_ie;
 198
 199         uwb_ie_drp_set_unsafe(drp_ie,       unsafe);
 200         uwb_ie_drp_set_tiebreaker(drp_ie,   rsv->tiebreaker);
 201         uwb_ie_drp_set_owner(drp_ie,        uwb_rsv_is_owner(rsv));
 202         uwb_ie_drp_set_status(drp_ie,       uwb_rsv_status(rsv));
 203         uwb_ie_drp_set_reason_code(drp_ie,  uwb_rsv_reason_code(rsv));
 204         uwb_ie_drp_set_stream_index(drp_ie, rsv->stream);
 205         uwb_ie_drp_set_type(drp_ie,         rsv->type);
 206
 207         if (uwb_rsv_is_owner(rsv)) {
 208                 switch (rsv->target.type) {
 209                 case UWB_RSV_TARGET_DEV:
 210                         drp_ie->dev_addr = rsv->target.dev->dev_addr;
 211                         break;
 212                 case UWB_RSV_TARGET_DEVADDR:
 213                         drp_ie->dev_addr = rsv->target.devaddr;
 214                         break;
 215                 }
 216         } else
 217                 drp_ie->dev_addr = rsv->owner->dev_addr;
 218
 219         uwb_drp_ie_from_bm(drp_ie, &rsv->mas);
 220
 221         if (uwb_rsv_has_two_drp_ies(rsv)) {
 222                 mv = &rsv->mv;
 223                 if (mv->companion_drp_ie == NULL) {
 224                         mv->companion_drp_ie = uwb_drp_ie_alloc();
 225                         if (mv->companion_drp_ie == NULL)
 226                                 return -ENOMEM;
 227                 }
 228                 drp_ie = mv->companion_drp_ie;
 229
 230                 /* keep all the same configuration of the main drp_ie */
 231                 memcpy(drp_ie, rsv->drp_ie, sizeof(struct uwb_ie_drp));
 232
 233
 234                 /* FIXME: handle properly the unsafe bit */
 235                 uwb_ie_drp_set_unsafe(drp_ie,       1);
 236                 uwb_ie_drp_set_status(drp_ie,       uwb_rsv_companion_status(rsv));
 237                 uwb_ie_drp_set_reason_code(drp_ie,  uwb_rsv_companion_reason_code(rsv));
 238
 239                 uwb_drp_ie_from_bm(drp_ie, &mv->companion_mas);
 240         }
 241
 242         rsv->ie_valid = true;
 243         return 0;
 244 }
 245
 246 /*
 247  * Set MAS bits from given MAS bitmap in a single zone of large bitmap.
 248  *
 249  * We are given a zone id and the MAS bitmap of bits that need to be set in
 250  * this zone. Note that this zone may already have bits set and this only
 251  * adds settings - we cannot simply assign the MAS bitmap contents to the
 252  * zone contents. We iterate over the the bits (MAS) in the zone and set the
 253  * bits that are set in the given MAS bitmap.
 254  */
 255 static
 256 void uwb_drp_ie_single_zone_to_bm(struct uwb_mas_bm *bm, u8 zone, u16 mas_bm)
 257 {
 258         int mas;
 259         u16 mas_mask;
 260
 261         for (mas = 0; mas < UWB_MAS_PER_ZONE; mas++) {
 262                 mas_mask = 1 << mas;
 263                 if (mas_bm & mas_mask)
 264                         set_bit(zone * UWB_NUM_ZONES + mas, bm->bm);
 265         }
 266 }
 267
 268 /**
 269  * uwb_drp_ie_zones_to_bm - convert DRP allocation fields to a bitmap
 270  * @mas:    MAS bitmap that will be populated to correspond to the
 271  *          allocation fields in the DRP IE
 272  * @drp_ie: the DRP IE that contains the allocation fields.
 273  *
 274  * The input format is an array of MAS allocation fields (16 bit Zone
 275  * bitmap, 16 bit MAS bitmap) as described in [ECMA-368] section
 276  * 16.8.6. The output is a full 256 bit MAS bitmap.
 277  *
 278  * We go over all the allocation fields, for each allocation field we
 279  * know which zones are impacted. We iterate over all the zones
 280  * impacted and call a function that will set the correct MAS bits in
 281  * each zone.
 282  */
 283 void uwb_drp_ie_to_bm(struct uwb_mas_bm *bm, const struct uwb_ie_drp *drp_ie)
 284 {
 285         int numallocs = (drp_ie->hdr.length - 4) / 4;
 286         const struct uwb_drp_alloc *alloc;
 287         int cnt;
 288         u16 zone_bm, mas_bm;
 289         u8 zone;
 290         u16 zone_mask;
 291
 292         bitmap_zero(bm->bm, UWB_NUM_MAS);
 293
 294         for (cnt = 0; cnt < numallocs; cnt++) {
 295                 alloc = &drp_ie->allocs[cnt];
 296                 zone_bm = le16_to_cpu(alloc->zone_bm);
 297                 mas_bm = le16_to_cpu(alloc->mas_bm);
 298                 for (zone = 0; zone < UWB_NUM_ZONES; zone++)   {
 299                         zone_mask = 1 << zone;
 300                         if (zone_bm & zone_mask)
 301                                 uwb_drp_ie_single_zone_to_bm(bm, zone, mas_bm);
 302                 }
 303         }
 304 }
 305