LXR linux/drivers/net/wireless/ath/dfs_pattern

   1/*
   2 * Copyright (c) 2012 Neratec Solutions AG
   3 *
   4 * Permission to use, copy, modify, and/or distribute this software for any
   5 * purpose with or without fee is hereby granted, provided that the above
   6 * copyright notice and this permission notice appear in all copies.
   7 *
   8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15 */
  16
  17#include <linux/slab.h>
  18#include <linux/export.h>
  19
  20#include "dfs_pattern_detector.h"
  21#include "dfs_pri_detector.h"
  22#include "ath.h"
  23
  24/*
  25 * tolerated deviation of radar time stamp in usecs on both sides
  26 * TODO: this might need to be HW-dependent
  27 */
  28#define PRI_TOLERANCE   16
  29
  30/**
  31 * struct radar_types - contains array of patterns defined for one DFS domain
  32 * @domain: DFS regulatory domain
  33 * @num_radar_types: number of radar types to follow
  34 * @radar_types: radar types array
  35 */
  36struct radar_types {
  37        enum nl80211_dfs_regions region;
  38        u32 num_radar_types;
  39        const struct radar_detector_specs *radar_types;
  40};
  41
  42/* percentage on ppb threshold to trigger detection */
  43#define MIN_PPB_THRESH  50
  44#define PPB_THRESH(PPB) ((PPB * MIN_PPB_THRESH + 50) / 100)
  45#define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF)
  46/* percentage of pulse width tolerance */
  47#define WIDTH_TOLERANCE 5
  48#define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100)
  49#define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100)
  50
  51#define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB)      \
  52{                                                               \
  53        ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX),               \
  54        (PRF2PRI(PMAX) - PRI_TOLERANCE),                        \
  55        (PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF,  \
  56        PPB_THRESH(PPB), PRI_TOLERANCE,                         \
  57}
  58
  59/* radar types as defined by ETSI EN-301-893 v1.5.1 */
  60static const struct radar_detector_specs etsi_radar_ref_types_v15[] = {
  61        ETSI_PATTERN(0,  0,  1,  700,  700, 1, 18),
  62        ETSI_PATTERN(1,  0,  5,  200, 1000, 1, 10),
  63        ETSI_PATTERN(2,  0, 15,  200, 1600, 1, 15),
  64        ETSI_PATTERN(3,  0, 15, 2300, 4000, 1, 25),
  65        ETSI_PATTERN(4, 20, 30, 2000, 4000, 1, 20),
  66        ETSI_PATTERN(5,  0,  2,  300,  400, 3, 10),
  67        ETSI_PATTERN(6,  0,  2,  400, 1200, 3, 15),
  68};
  69
  70static const struct radar_types etsi_radar_types_v15 = {
  71        .region                 = NL80211_DFS_ETSI,
  72        .num_radar_types        = ARRAY_SIZE(etsi_radar_ref_types_v15),
  73        .radar_types            = etsi_radar_ref_types_v15,
  74};
  75
  76#define FCC_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB)       \
  77{                                                               \
  78        ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX),               \
  79        PMIN - PRI_TOLERANCE,                                   \
  80        PMAX * PRF + PRI_TOLERANCE, PRF, PPB * PRF,             \
  81        PPB_THRESH(PPB), PRI_TOLERANCE,                         \
  82}
  83
  84static const struct radar_detector_specs fcc_radar_ref_types[] = {
  85        FCC_PATTERN(0, 0, 1, 1428, 1428, 1, 18),
  86        FCC_PATTERN(1, 0, 5, 150, 230, 1, 23),
  87        FCC_PATTERN(2, 6, 10, 200, 500, 1, 16),
  88        FCC_PATTERN(3, 11, 20, 200, 500, 1, 12),
  89        FCC_PATTERN(4, 50, 100, 1000, 2000, 1, 1),
  90        FCC_PATTERN(5, 0, 1, 333, 333, 1, 9),
  91};
  92
  93static const struct radar_types fcc_radar_types = {
  94        .region                 = NL80211_DFS_FCC,
  95        .num_radar_types        = ARRAY_SIZE(fcc_radar_ref_types),
  96        .radar_types            = fcc_radar_ref_types,
  97};
  98
  99#define JP_PATTERN FCC_PATTERN
 100static const struct radar_detector_specs jp_radar_ref_types[] = {
 101        JP_PATTERN(0, 0, 1, 1428, 1428, 1, 18),
 102        JP_PATTERN(1, 2, 3, 3846, 3846, 1, 18),
 103        JP_PATTERN(2, 0, 1, 1388, 1388, 1, 18),
 104        JP_PATTERN(3, 1, 2, 4000, 4000, 1, 18),
 105        JP_PATTERN(4, 0, 5, 150, 230, 1, 23),
 106        JP_PATTERN(5, 6, 10, 200, 500, 1, 16),
 107        JP_PATTERN(6, 11, 20, 200, 500, 1, 12),
 108        JP_PATTERN(7, 50, 100, 1000, 2000, 1, 20),
 109        JP_PATTERN(5, 0, 1, 333, 333, 1, 9),
 110};
 111
 112static const struct radar_types jp_radar_types = {
 113        .region                 = NL80211_DFS_JP,
 114        .num_radar_types        = ARRAY_SIZE(jp_radar_ref_types),
 115        .radar_types            = jp_radar_ref_types,
 116};
 117
 118static const struct radar_types *dfs_domains[] = {
 119        &etsi_radar_types_v15,
 120        &fcc_radar_types,
 121        &jp_radar_types,
 122};
 123
 124/**
 125 * get_dfs_domain_radar_types() - get radar types for a given DFS domain
 126 * @param domain DFS domain
 127 * @return radar_types ptr on success, NULL if DFS domain is not supported
 128 */
 129static const struct radar_types *
 130get_dfs_domain_radar_types(enum nl80211_dfs_regions region)
 131{
 132        u32 i;
 133        for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) {
 134                if (dfs_domains[i]->region == region)
 135                        return dfs_domains[i];
 136        }
 137        return NULL;
 138}
 139
 140/**
 141 * struct channel_detector - detector elements for a DFS channel
 142 * @head: list_head
 143 * @freq: frequency for this channel detector in MHz
 144 * @detectors: array of dynamically created detector elements for this freq
 145 *
 146 * Channel detectors are required to provide multi-channel DFS detection, e.g.
 147 * to support off-channel scanning. A pattern detector has a list of channels
 148 * radar pulses have been reported for in the past.
 149 */
 150struct channel_detector {
 151        struct list_head head;
 152        u16 freq;
 153        struct pri_detector **detectors;
 154};
 155
 156/* channel_detector_reset() - reset detector lines for a given channel */
 157static void channel_detector_reset(struct dfs_pattern_detector *dpd,
 158                                   struct channel_detector *cd)
 159{
 160        u32 i;
 161        if (cd == NULL)
 162                return;
 163        for (i = 0; i < dpd->num_radar_types; i++)
 164                cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts);
 165}
 166
 167/* channel_detector_exit() - destructor */
 168static void channel_detector_exit(struct dfs_pattern_detector *dpd,
 169                                  struct channel_detector *cd)
 170{
 171        u32 i;
 172        if (cd == NULL)
 173                return;
 174        list_del(&cd->head);
 175        for (i = 0; i < dpd->num_radar_types; i++) {
 176                struct pri_detector *de = cd->detectors[i];
 177                if (de != NULL)
 178                        de->exit(de);
 179        }
 180        kfree(cd->detectors);
 181        kfree(cd);
 182}
 183
 184static struct channel_detector *
 185channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq)
 186{
 187        u32 sz, i;
 188        struct channel_detector *cd;
 189
 190        cd = kmalloc(sizeof(*cd), GFP_ATOMIC);
 191        if (cd == NULL)
 192                goto fail;
 193
 194        INIT_LIST_HEAD(&cd->head);
 195        cd->freq = freq;
 196        sz = sizeof(cd->detectors) * dpd->num_radar_types;
 197        cd->detectors = kzalloc(sz, GFP_ATOMIC);
 198        if (cd->detectors == NULL)
 199                goto fail;
 200
 201        for (i = 0; i < dpd->num_radar_types; i++) {
 202                const struct radar_detector_specs *rs = &dpd->radar_spec[i];
 203                struct pri_detector *de = pri_detector_init(rs);
 204                if (de == NULL)
 205                        goto fail;
 206                cd->detectors[i] = de;
 207        }
 208        list_add(&cd->head, &dpd->channel_detectors);
 209        return cd;
 210
 211fail:
 212        ath_dbg(dpd->common, DFS,
 213                "failed to allocate channel_detector for freq=%d\n", freq);
 214        channel_detector_exit(dpd, cd);
 215        return NULL;
 216}
 217
 218/**
 219 * channel_detector_get() - get channel detector for given frequency
 220 * @param dpd instance pointer
 221 * @param freq frequency in MHz
 222 * @return pointer to channel detector on success, NULL otherwise
 223 *
 224 * Return existing channel detector for the given frequency or return a
 225 * newly create one.
 226 */
 227static struct channel_detector *
 228channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq)
 229{
 230        struct channel_detector *cd;
 231        list_for_each_entry(cd, &dpd->channel_detectors, head) {
 232                if (cd->freq == freq)
 233                        return cd;
 234        }
 235        return channel_detector_create(dpd, freq);
 236}
 237
 238/*
 239 * DFS Pattern Detector
 240 */
 241
 242/* dpd_reset(): reset all channel detectors */
 243static void dpd_reset(struct dfs_pattern_detector *dpd)
 244{
 245        struct channel_detector *cd;
 246        if (!list_empty(&dpd->channel_detectors))
 247                list_for_each_entry(cd, &dpd->channel_detectors, head)
 248                        channel_detector_reset(dpd, cd);
 249
 250}
 251static void dpd_exit(struct dfs_pattern_detector *dpd)
 252{
 253        struct channel_detector *cd, *cd0;
 254        if (!list_empty(&dpd->channel_detectors))
 255                list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
 256                        channel_detector_exit(dpd, cd);
 257        kfree(dpd);
 258}
 259
 260static bool
 261dpd_add_pulse(struct dfs_pattern_detector *dpd, struct pulse_event *event)
 262{
 263        u32 i;
 264        struct channel_detector *cd;
 265
 266        /*
 267         * pulses received for a non-supported or un-initialized
 268         * domain are treated as detected radars for fail-safety
 269         */
 270        if (dpd->region == NL80211_DFS_UNSET)
 271                return true;
 272
 273        cd = channel_detector_get(dpd, event->freq);
 274        if (cd == NULL)
 275                return false;
 276
 277        dpd->last_pulse_ts = event->ts;
 278        /* reset detector on time stamp wraparound, caused by TSF reset */
 279        if (event->ts < dpd->last_pulse_ts)
 280                dpd_reset(dpd);
 281
 282        /* do type individual pattern matching */
 283        for (i = 0; i < dpd->num_radar_types; i++) {
 284                struct pri_detector *pd = cd->detectors[i];
 285                struct pri_sequence *ps = pd->add_pulse(pd, event);
 286                if (ps != NULL) {
 287                        ath_dbg(dpd->common, DFS,
 288                                "DFS: radar found on freq=%d: id=%d, pri=%d, "
 289                                "count=%d, count_false=%d\n",
 290                                event->freq, pd->rs->type_id,
 291                                ps->pri, ps->count, ps->count_falses);
 292                        channel_detector_reset(dpd, cd);
 293                        return true;
 294                }
 295        }
 296        return false;
 297}
 298
 299static struct ath_dfs_pool_stats
 300dpd_get_stats(struct dfs_pattern_detector *dpd)
 301{
 302        return global_dfs_pool_stats;
 303}
 304
 305static bool dpd_set_domain(struct dfs_pattern_detector *dpd,
 306                           enum nl80211_dfs_regions region)
 307{
 308        const struct radar_types *rt;
 309        struct channel_detector *cd, *cd0;
 310
 311        if (dpd->region == region)
 312                return true;
 313
 314        dpd->region = NL80211_DFS_UNSET;
 315
 316        rt = get_dfs_domain_radar_types(region);
 317        if (rt == NULL)
 318                return false;
 319
 320        /* delete all channel detectors for previous DFS domain */
 321        if (!list_empty(&dpd->channel_detectors))
 322                list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
 323                        channel_detector_exit(dpd, cd);
 324        dpd->radar_spec = rt->radar_types;
 325        dpd->num_radar_types = rt->num_radar_types;
 326
 327        dpd->region = region;
 328        return true;
 329}
 330
 331static struct dfs_pattern_detector default_dpd = {
 332        .exit           = dpd_exit,
 333        .set_dfs_domain = dpd_set_domain,
 334        .add_pulse      = dpd_add_pulse,
 335        .get_stats      = dpd_get_stats,
 336        .region         = NL80211_DFS_UNSET,
 337};
 338
 339struct dfs_pattern_detector *
 340dfs_pattern_detector_init(struct ath_common *common,
 341                          enum nl80211_dfs_regions region)
 342{
 343        struct dfs_pattern_detector *dpd;
 344
 345        if (!config_enabled(CONFIG_CFG80211_CERTIFICATION_ONUS))
 346                return NULL;
 347
 348        dpd = kmalloc(sizeof(*dpd), GFP_KERNEL);
 349        if (dpd == NULL)
 350                return NULL;
 351
 352        *dpd = default_dpd;
 353        INIT_LIST_HEAD(&dpd->channel_detectors);
 354
 355        dpd->common = common;
 356        if (dpd->set_dfs_domain(dpd, region))
 357                return dpd;
 358
 359        ath_dbg(common, DFS,"Could not set DFS domain to %d", region);
 360        kfree(dpd);
 361        return NULL;
 362}
 363EXPORT_SYMBOL(dfs_pattern_detector_init);
 364