package/madwifi/patches/460-autochannel_multi.patch

   1 --- a/net80211/ieee80211_scan.c
   2 +++ b/net80211/ieee80211_scan.c
   3 @@ -97,6 +97,123 @@ struct scan_state {
   4  static void scan_restart_pwrsav(unsigned long);
   5  static void scan_next(unsigned long);
   6
   7 +spinlock_t channel_lock = SPIN_LOCK_UNLOCKED;
   8 +static LIST_HEAD(channels_inuse);
   9 +
  10 +struct channel_inuse {
  11 +       struct list_head list;
  12 +       struct ieee80211com *ic;
  13 +       u16 freq;
  14 +       u8 bw;
  15 +};
  16 +
  17 +static inline u32
  18 +get_signal(u8 bw, u8 distance)
  19 +{
  20 +       u32 v;
  21 +
  22 +       /* signal = 1 - (distance / bw)^2 [scale: 100] */
  23 +       v = 100 * distance / bw;
  24 +       v = (100 - ((v * v) / 100));
  25 +       return v;
  26 +}
  27 +
  28 +static u32
  29 +get_overlap(u16 f1, u16 f2, u8 b1, u8 b2)
  30 +{
  31 +       u32 v;
  32 +       u16 d, c;
  33 +
  34 +       /* add offsets for sidechannel interference */
  35 +       b1 += (b1 / 5);
  36 +       b2 += (b2 / 5);
  37 +
  38 +       /* use only one direction */
  39 +       b1 /= 2;
  40 +       b2 /= 2;
  41 +
  42 +       if (f1 + b1 < f2 - b2)
  43 +               return 0;
  44 +
  45 +       d = f2 - f1;
  46 +       c = d * b1 / (b1 + b2);
  47 +       v = get_signal(b1, c);
  48 +
  49 +       return v * v / 100;
  50 +}
  51 +
  52 +static u8
  53 +get_channel_bw(struct ieee80211_channel *c)
  54 +{
  55 +       switch(c->ic_flags & (
  56 +               IEEE80211_CHAN_HALF |
  57 +               IEEE80211_CHAN_QUARTER |
  58 +               IEEE80211_CHAN_TURBO |
  59 +               IEEE80211_CHAN_STURBO)) {
  60 +       case IEEE80211_CHAN_QUARTER:
  61 +               return 5;
  62 +       case IEEE80211_CHAN_HALF:
  63 +               return 10;
  64 +       case IEEE80211_CHAN_TURBO:
  65 +       case IEEE80211_CHAN_STURBO:
  66 +               return 40;
  67 +       default:
  68 +               return 20;
  69 +       }
  70 +}
  71 +
  72 +/* must be called with channel_lock held */
  73 +u32
  74 +ieee80211_scan_get_bias(struct ieee80211_channel *c)
  75 +{
  76 +       struct channel_inuse *ch;
  77 +       u8 bw = get_channel_bw(c);
  78 +       u32 bias = 0;
  79 +
  80 +       list_for_each_entry(ch, &channels_inuse, list) {
  81 +               if (ch->freq == c->ic_freq) {
  82 +                       bias += 50;
  83 +                       continue;
  84 +               }
  85 +               if (c->ic_freq < ch->freq)
  86 +                       bias += get_overlap(c->ic_freq, ch->freq, bw, ch->bw);
  87 +               else
  88 +                       bias += get_overlap(ch->freq, c->ic_freq, ch->bw, bw);
  89 +       }
  90 +       return min(bias, (u32) 100);
  91 +}
  92 +EXPORT_SYMBOL(ieee80211_scan_get_bias);
  93 +
  94 +/* must be called with channel_lock held */
  95 +void
  96 +ieee80211_scan_set_bss_channel(struct ieee80211com *ic, struct ieee80211_channel *c)
  97 +{
  98 +       unsigned long flags;
  99 +       struct channel_inuse *ch;
 100 +
 101 +       list_for_each_entry(ch, &channels_inuse, list) {
 102 +               if (ch->ic == ic)
 103 +                       goto found;
 104 +       }
 105 +       ch = NULL;
 106 +found:
 107 +       if (c && (c != IEEE80211_CHAN_ANYC)) {
 108 +               if (!ch) {
 109 +                       ch = kmalloc(sizeof(struct channel_inuse), GFP_ATOMIC);
 110 +                       ch->ic = ic;
 111 +                       INIT_LIST_HEAD(&ch->list);
 112 +                       list_add(&ch->list, &channels_inuse);
 113 +               }
 114 +               ch->freq = c->ic_freq;
 115 +               ch->bw = get_channel_bw(c);
 116 +       } else if (ch) {
 117 +               list_del(&ch->list);
 118 +               kfree(ch);
 119 +       }
 120 +}
 121 +EXPORT_SYMBOL(ieee80211_scan_set_bss_channel);
 122 +
 123 +
 124  void
 125  ieee80211_scan_attach(struct ieee80211com *ic)
 126  {
 127 @@ -1155,7 +1272,7 @@ ieee80211_scan_dfs_action(struct ieee802
 128                                 IEEE80211_RADAR_CHANCHANGE_TBTT_COUNT;
 129                         ic->ic_flags |= IEEE80211_F_CHANSWITCH;
 130                 } else {
 131 -
 132 +                       unsigned long flags;
 133                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH,
 134                                         "%s: directly switching to channel "
 135                                         "%3d (%4d MHz)\n", __func__,
 136 @@ -1166,6 +1283,9 @@ ieee80211_scan_dfs_action(struct ieee802
 137                          * change the channel here. */
 138                         change_channel(ic, new_channel);
 139                         ic->ic_bsschan = new_channel;
 140 +                       spin_lock_irqsave(&channel_lock, flags);
 141 +                       ieee80211_scan_set_bss_channel(ic, ic->ic_bsschan);
 142 +                       spin_unlock_irqrestore(&channel_lock, flags);
 143                         if (vap->iv_bss)
 144                                 vap->iv_bss->ni_chan = new_channel;
 145                 }
 146 --- a/net80211/ieee80211_scan.h
 147 +++ b/net80211/ieee80211_scan.h
 148 @@ -35,6 +35,7 @@
 149
 150  #define        IEEE80211_SCAN_MAX      IEEE80211_CHAN_MAX
 151
 152 +extern spinlock_t channel_lock;
 153  struct ieee80211_scanner;
 154  struct ieee80211_scan_entry;
 155
 156 @@ -116,6 +117,8 @@ void ieee80211_scan_flush(struct ieee802
 157  struct ieee80211_scan_entry;
 158  typedef int ieee80211_scan_iter_func(void *, const struct ieee80211_scan_entry *);
 159  int ieee80211_scan_iterate(struct ieee80211com *, ieee80211_scan_iter_func *, void *);
 160 +u32 ieee80211_scan_get_bias(struct ieee80211_channel *c);
 161 +void ieee80211_scan_set_bss_channel(struct ieee80211com *ic, struct ieee80211_channel *c);
 162
 163  /*
 164   * Parameters supplied when adding/updating an entry in a
 165 --- a/net80211/ieee80211.c
 166 +++ b/net80211/ieee80211.c
 167 @@ -373,8 +373,16 @@ void
 168  ieee80211_ifdetach(struct ieee80211com *ic)
 169  {
 170         struct ieee80211vap *vap;
 171 +       unsigned long flags;
 172         int count;
 173
 174 +       /* mark the channel as no longer in use */
 175 +       ic->ic_bsschan = IEEE80211_CHAN_ANYC;
 176 +       spin_lock_irqsave(&channel_lock, flags);
 177 +       ieee80211_scan_set_bss_channel(ic, ic->ic_bsschan);
 178 +       spin_unlock_irqrestore(&channel_lock, flags);
 179 +
 180 +
 181         /* bring down all vaps */
 182         TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
 183                 ieee80211_stop(vap->iv_dev);
 184 --- a/net80211/ieee80211_input.c
 185 +++ b/net80211/ieee80211_input.c
 186 @@ -2772,6 +2772,7 @@ static void
 187  ieee80211_doth_switch_channel(struct ieee80211vap *vap)
 188  {
 189         struct ieee80211com *ic = vap->iv_ic;
 190 +       unsigned long flags;
 191
 192         IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH,
 193                           "%s: Channel switch to %3d (%4d MHz) NOW!\n",
 194 @@ -2794,6 +2795,9 @@ ieee80211_doth_switch_channel(struct iee
 195
 196         ic->ic_curchan = ic->ic_bsschan = vap->iv_csa_chan;
 197         ic->ic_set_channel(ic);
 198 +       spin_lock_irqsave(&channel_lock, flags);
 199 +       ieee80211_scan_set_bss_channel(ic, ic->ic_bsschan);
 200 +       spin_unlock_irqrestore(&channel_lock, flags);
 201  }
 202
 203  static void
 204 --- a/net80211/ieee80211_node.c
 205 +++ b/net80211/ieee80211_node.c
 206 @@ -308,6 +308,7 @@ ieee80211_create_ibss(struct ieee80211va
 207  {
 208         struct ieee80211com *ic = vap->iv_ic;
 209         struct ieee80211_node *ni;
 210 +       unsigned long flags;
 211
 212         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 213                 "%s: creating ibss on channel %u\n", __func__,
 214 @@ -386,6 +387,9 @@ ieee80211_create_ibss(struct ieee80211va
 215         ic->ic_bsschan = chan;
 216         ieee80211_node_set_chan(ic, ni);
 217         ic->ic_curmode = ieee80211_chan2mode(chan);
 218 +       spin_lock_irqsave(&channel_lock, flags);
 219 +       ieee80211_scan_set_bss_channel(ic, ic->ic_bsschan);
 220 +       spin_unlock_irqrestore(&channel_lock, flags);
 221
 222         /* Update country ie information */
 223         ieee80211_build_countryie(ic);
 224 @@ -622,6 +626,7 @@ ieee80211_sta_join1(struct ieee80211_nod
 225         struct ieee80211vap *vap = selbs->ni_vap;
 226         struct ieee80211com *ic = selbs->ni_ic;
 227         struct ieee80211_node *obss;
 228 +       unsigned long flags;
 229         int canreassoc;
 230
 231         if (vap->iv_opmode == IEEE80211_M_IBSS) {
 232 @@ -650,6 +655,9 @@ ieee80211_sta_join1(struct ieee80211_nod
 233         ic->ic_curchan = ic->ic_bsschan;
 234         ic->ic_curmode = ieee80211_chan2mode(ic->ic_curchan);
 235         ic->ic_set_channel(ic);
 236 +       spin_lock_irqsave(&channel_lock, flags);
 237 +       ieee80211_scan_set_bss_channel(ic, ic->ic_bsschan);
 238 +       spin_unlock_irqrestore(&channel_lock, flags);
 239         /*
 240          * Set the erp state (mostly the slot time) to deal with
 241          * the auto-select case; this should be redundant if the
 242 --- a/net80211/ieee80211_proto.c
 243 +++ b/net80211/ieee80211_proto.c
 244 @@ -1225,6 +1225,7 @@ ieee80211_dturbo_switch(struct ieee80211
 245         struct ieee80211vap *vap = TAILQ_FIRST(&ic->ic_vaps);
 246  #endif
 247         struct ieee80211_channel *chan;
 248 +       unsigned long flags;
 249
 250         chan = ieee80211_find_channel(ic, ic->ic_bsschan->ic_freq, newflags);
 251         if (chan == NULL) {             /* XXX should not happen */
 252 @@ -1243,6 +1244,9 @@ ieee80211_dturbo_switch(struct ieee80211
 253         ic->ic_bsschan = chan;
 254         ic->ic_curchan = chan;
 255         ic->ic_set_channel(ic);
 256 +       spin_lock_irqsave(&channel_lock, flags);
 257 +       ieee80211_scan_set_bss_channel(ic, ic->ic_bsschan);
 258 +       spin_unlock_irqrestore(&channel_lock, flags);
 259         /* NB: do not need to reset ERP state because in sta mode */
 260  }
 261  EXPORT_SYMBOL(ieee80211_dturbo_switch);
 262 --- a/net80211/ieee80211_wireless.c
 263 +++ b/net80211/ieee80211_wireless.c
 264 @@ -4076,8 +4076,13 @@ ieee80211_ioctl_setchanlist(struct net_d
 265         if (nchan == 0)                 /* no valid channels, disallow */
 266                 return -EINVAL;
 267         if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&    /* XXX */
 268 -           isclr(chanlist, ic->ic_bsschan->ic_ieee))
 269 +           isclr(chanlist, ic->ic_bsschan->ic_ieee)) {
 270 +               unsigned long flags;
 271                 ic->ic_bsschan = IEEE80211_CHAN_ANYC;   /* invalidate */
 272 +               spin_lock_irqsave(&channel_lock, flags);
 273 +               ieee80211_scan_set_bss_channel(ic, ic->ic_bsschan);
 274 +               spin_unlock_irqrestore(&channel_lock, flags);
 275 +       }
 276
 277         memcpy(ic->ic_chan_active, chanlist, sizeof(ic->ic_chan_active));
 278         /* update Supported Channels information element */
 279 --- a/net80211/ieee80211_scan_ap.c
 280 +++ b/net80211/ieee80211_scan_ap.c
 281 @@ -213,9 +213,15 @@ ap_start(struct ieee80211_scan_state *ss
 282         struct ieee80211com *ic     = NULL;
 283         int i;
 284         unsigned int mode = 0;
 285 +       unsigned long sflags;
 286
 287         SCAN_AP_LOCK_IRQ(as);
 288         ic = vap->iv_ic;
 289 +
 290 +       spin_lock_irqsave(&channel_lock, sflags);
 291 +       ieee80211_scan_set_bss_channel(ic, NULL);
 292 +       spin_unlock_irqrestore(&channel_lock, sflags);
 293 +
 294         /* Determine mode flags to match, or leave zero for auto mode */
 295         as->as_vap_desired_mode = vap->iv_des_mode;
 296         as->as_required_mode    = 0;
 297 @@ -429,8 +435,10 @@ pc_cmp_idletime(struct ieee80211_channel
 298         if (!a->ic_idletime || !b->ic_idletime)
 299                 return 0;
 300
 301 -       /* a is better than b (return < 0) when a has more idle time than b */
 302 -       return b->ic_idletime - a->ic_idletime;
 303 +       /* a is better than b (return < 0) when a has more idle and less bias time than b */
 304 +       return
 305 +               ((100 - (u32) a->ic_idletime) + ieee80211_scan_get_bias(a)) -
 306 +               ((100 - (u32) b->ic_idletime) + ieee80211_scan_get_bias(b));
 307  }
 308
 309
 310 @@ -616,6 +624,7 @@ ap_end(struct ieee80211_scan_state *ss,
 311         struct ap_state *as = ss->ss_priv;
 312         struct ieee80211_channel *bestchan = NULL;
 313         struct ieee80211com *ic = NULL;
 314 +       unsigned long sflags;
 315         int res = 1;
 316
 317         SCAN_AP_LOCK_IRQ(as);
 318 @@ -624,8 +633,11 @@ ap_end(struct ieee80211_scan_state *ss,
 319                 ("wrong opmode %u", vap->iv_opmode));
 320
 321         ic = vap->iv_ic;
 322 +       spin_lock_irqsave(&channel_lock, sflags);
 323 +       ieee80211_scan_set_bss_channel(ic, NULL);
 324         bestchan = pick_channel(ss, vap, flags);
 325         if (bestchan == NULL) {
 326 +               spin_unlock_irqrestore(&channel_lock, sflags);
 327                 if (ss->ss_last > 0) {
 328                         /* no suitable channel, should not happen */
 329                         printk(KERN_ERR "%s: %s: no suitable channel! "
 330 @@ -644,6 +656,7 @@ ap_end(struct ieee80211_scan_state *ss,
 331                                         bestchan->ic_freq, bestchan->ic_flags &
 332                                         ~IEEE80211_CHAN_TURBO)) == NULL) {
 333                                 /* should never happen ?? */
 334 +                               spin_unlock_irqrestore(&channel_lock, sflags);
 335                                 SCAN_AP_UNLOCK_IRQ_EARLY(as);
 336                                 return 0;
 337                         }
 338 @@ -656,6 +669,9 @@ ap_end(struct ieee80211_scan_state *ss,
 339                         as->as_action = action;
 340                 as->as_selbss = se;
 341
 342 +               ieee80211_scan_set_bss_channel(ic, bestchan);
 343 +               spin_unlock_irqrestore(&channel_lock, sflags);
 344 +
 345                 /* Must defer action to avoid possible recursive call through
 346                  * 80211 state machine, which would result in recursive
 347                  * locking. */