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 * struct radar_types - contains array of patterns defined for one DFS domain
  26 * @domain: DFS regulatory domain
  27 * @num_radar_types: number of radar types to follow
  28 * @radar_types: radar types array
  29 */
  30struct radar_types {
  31        enum nl80211_dfs_regions region;
  32        u32 num_radar_types;
  33        const struct radar_detector_specs *radar_types;
  34};
  35
  36/* percentage on ppb threshold to trigger detection */
  37#define MIN_PPB_THRESH  50
  38#define PPB_THRESH_RATE(PPB, RATE) ((PPB * RATE + 100 - RATE) / 100)
  39#define PPB_THRESH(PPB) PPB_THRESH_RATE(PPB, MIN_PPB_THRESH)
  40#define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF)
  41/* percentage of pulse width tolerance */
  42#define WIDTH_TOLERANCE 5
  43#define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100)
  44#define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100)
  45
  46#define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, CHIRP)       \
  47{                                                               \
  48        ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX),               \
  49        (PRF2PRI(PMAX) - PRI_TOLERANCE),                        \
  50        (PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF,  \
  51        PPB_THRESH(PPB), PRI_TOLERANCE, CHIRP                   \
  52}
  53
  54/* radar types as defined by ETSI EN-301-893 v1.5.1 */
  55static const struct radar_detector_specs etsi_radar_ref_types_v15[] = {
  56        ETSI_PATTERN(0,  0,  1,  700,  700, 1, 18, false),
  57        ETSI_PATTERN(1,  0,  5,  200, 1000, 1, 10, false),
  58        ETSI_PATTERN(2,  0, 15,  200, 1600, 1, 15, false),
  59        ETSI_PATTERN(3,  0, 15, 2300, 4000, 1, 25, false),
  60        ETSI_PATTERN(4, 20, 30, 2000, 4000, 1, 20, false),
  61        ETSI_PATTERN(5,  0,  2,  300,  400, 3, 10, false),
  62        ETSI_PATTERN(6,  0,  2,  400, 1200, 3, 15, false),
  63};
  64
  65static const struct radar_types etsi_radar_types_v15 = {
  66        .region                 = NL80211_DFS_ETSI,
  67        .num_radar_types        = ARRAY_SIZE(etsi_radar_ref_types_v15),
  68        .radar_types            = etsi_radar_ref_types_v15,
  69};
  70
  71#define FCC_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, CHIRP)        \
  72{                                                               \
  73        ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX),               \
  74        PMIN - PRI_TOLERANCE,                                   \
  75        PMAX * PRF + PRI_TOLERANCE, PRF, PPB * PRF,             \
  76        PPB_THRESH(PPB), PRI_TOLERANCE, CHIRP                   \
  77}
  78
  79/* radar types released on August 14, 2014
  80 * type 1 PRI values randomly selected within the range of 518 and 3066.
  81 * divide it to 3 groups is good enough for both of radar detection and
  82 * avoiding false detection based on practical test results
  83 * collected for more than a year.
  84 */
  85static const struct radar_detector_specs fcc_radar_ref_types[] = {
  86        FCC_PATTERN(0, 0, 1, 1428, 1428, 1, 18, false),
  87        FCC_PATTERN(101, 0, 1, 518, 938, 1, 57, false),
  88        FCC_PATTERN(102, 0, 1, 938, 2000, 1, 27, false),
  89        FCC_PATTERN(103, 0, 1, 2000, 3066, 1, 18, false),
  90        FCC_PATTERN(2, 0, 5, 150, 230, 1, 23, false),
  91        FCC_PATTERN(3, 6, 10, 200, 500, 1, 16, false),
  92        FCC_PATTERN(4, 11, 20, 200, 500, 1, 12, false),
  93        FCC_PATTERN(5, 50, 100, 1000, 2000, 1, 1, true),
  94        FCC_PATTERN(6, 0, 1, 333, 333, 1, 9, false),
  95};
  96
  97static const struct radar_types fcc_radar_types = {
  98        .region                 = NL80211_DFS_FCC,
  99        .num_radar_types        = ARRAY_SIZE(fcc_radar_ref_types),
 100        .radar_types            = fcc_radar_ref_types,
 101};
 102
 103#define JP_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, RATE, CHIRP)   \
 104{                                                               \
 105        ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX),               \
 106        PMIN - PRI_TOLERANCE,                                   \
 107        PMAX * PRF + PRI_TOLERANCE, PRF, PPB * PRF,             \
 108        PPB_THRESH_RATE(PPB, RATE), PRI_TOLERANCE, CHIRP        \
 109}
 110static const struct radar_detector_specs jp_radar_ref_types[] = {
 111        JP_PATTERN(0, 0, 1, 1428, 1428, 1, 18, 29, false),
 112        JP_PATTERN(1, 2, 3, 3846, 3846, 1, 18, 29, false),
 113        JP_PATTERN(2, 0, 1, 1388, 1388, 1, 18, 50, false),
 114        JP_PATTERN(3, 1, 2, 4000, 4000, 1, 18, 50, false),
 115        JP_PATTERN(4, 0, 5, 150, 230, 1, 23, 50, false),
 116        JP_PATTERN(5, 6, 10, 200, 500, 1, 16, 50, false),
 117        JP_PATTERN(6, 11, 20, 200, 500, 1, 12, 50, false),
 118        JP_PATTERN(7, 50, 100, 1000, 2000, 1, 3, 50, false),
 119        JP_PATTERN(5, 0, 1, 333, 333, 1, 9, 50, false),
 120};
 121
 122static const struct radar_types jp_radar_types = {
 123        .region                 = NL80211_DFS_JP,
 124        .num_radar_types        = ARRAY_SIZE(jp_radar_ref_types),
 125        .radar_types            = jp_radar_ref_types,
 126};
 127
 128static const struct radar_types *dfs_domains[] = {
 129        &etsi_radar_types_v15,
 130        &fcc_radar_types,
 131        &jp_radar_types,
 132};
 133
 134/**
 135 * get_dfs_domain_radar_types() - get radar types for a given DFS domain
 136 * @param domain DFS domain
 137 * @return radar_types ptr on success, NULL if DFS domain is not supported
 138 */
 139static const struct radar_types *
 140get_dfs_domain_radar_types(enum nl80211_dfs_regions region)
 141{
 142        u32 i;
 143        for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) {
 144                if (dfs_domains[i]->region == region)
 145                        return dfs_domains[i];
 146        }
 147        return NULL;
 148}
 149
 150/**
 151 * struct channel_detector - detector elements for a DFS channel
 152 * @head: list_head
 153 * @freq: frequency for this channel detector in MHz
 154 * @detectors: array of dynamically created detector elements for this freq
 155 *
 156 * Channel detectors are required to provide multi-channel DFS detection, e.g.
 157 * to support off-channel scanning. A pattern detector has a list of channels
 158 * radar pulses have been reported for in the past.
 159 */
 160struct channel_detector {
 161        struct list_head head;
 162        u16 freq;
 163        struct pri_detector **detectors;
 164};
 165
 166/* channel_detector_reset() - reset detector lines for a given channel */
 167static void channel_detector_reset(struct dfs_pattern_detector *dpd,
 168                                   struct channel_detector *cd)
 169{
 170        u32 i;
 171        if (cd == NULL)
 172                return;
 173        for (i = 0; i < dpd->num_radar_types; i++)
 174                cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts);
 175}
 176
 177/* channel_detector_exit() - destructor */
 178static void channel_detector_exit(struct dfs_pattern_detector *dpd,
 179                                  struct channel_detector *cd)
 180{
 181        u32 i;
 182        if (cd == NULL)
 183                return;
 184        list_del(&cd->head);
 185        for (i = 0; i < dpd->num_radar_types; i++) {
 186                struct pri_detector *de = cd->detectors[i];
 187                if (de != NULL)
 188                        de->exit(de);
 189        }
 190        kfree(cd->detectors);
 191        kfree(cd);
 192}
 193
 194static struct channel_detector *
 195channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq)
 196{
 197        u32 sz, i;
 198        struct channel_detector *cd;
 199
 200        cd = kmalloc(sizeof(*cd), GFP_ATOMIC);
 201        if (cd == NULL)
 202                goto fail;
 203
 204        INIT_LIST_HEAD(&cd->head);
 205        cd->freq = freq;
 206        sz = sizeof(cd->detectors) * dpd->num_radar_types;
 207        cd->detectors = kzalloc(sz, GFP_ATOMIC);
 208        if (cd->detectors == NULL)
 209                goto fail;
 210
 211        for (i = 0; i < dpd->num_radar_types; i++) {
 212                const struct radar_detector_specs *rs = &dpd->radar_spec[i];
 213                struct pri_detector *de = pri_detector_init(rs);
 214                if (de == NULL)
 215                        goto fail;
 216                cd->detectors[i] = de;
 217        }
 218        list_add(&cd->head, &dpd->channel_detectors);
 219        return cd;
 220
 221fail:
 222        ath_dbg(dpd->common, DFS,
 223                "failed to allocate channel_detector for freq=%d\n", freq);
 224        channel_detector_exit(dpd, cd);
 225        return NULL;
 226}
 227
 228/**
 229 * channel_detector_get() - get channel detector for given frequency
 230 * @param dpd instance pointer
 231 * @param freq frequency in MHz
 232 * @return pointer to channel detector on success, NULL otherwise
 233 *
 234 * Return existing channel detector for the given frequency or return a
 235 * newly create one.
 236 */
 237static struct channel_detector *
 238channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq)
 239{
 240        struct channel_detector *cd;
 241        list_for_each_entry(cd, &dpd->channel_detectors, head) {
 242                if (cd->freq == freq)
 243                        return cd;
 244        }
 245        return channel_detector_create(dpd, freq);
 246}
 247
 248/*
 249 * DFS Pattern Detector
 250 */
 251
 252/* dpd_reset(): reset all channel detectors */
 253static void dpd_reset(struct dfs_pattern_detector *dpd)
 254{
 255        struct channel_detector *cd;
 256        if (!list_empty(&dpd->channel_detectors))
 257                list_for_each_entry(cd, &dpd->channel_detectors, head)
 258                        channel_detector_reset(dpd, cd);
 259
 260}
 261static void dpd_exit(struct dfs_pattern_detector *dpd)
 262{
 263        struct channel_detector *cd, *cd0;
 264        if (!list_empty(&dpd->channel_detectors))
 265                list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
 266                        channel_detector_exit(dpd, cd);
 267        kfree(dpd);
 268}
 269
 270static bool
 271dpd_add_pulse(struct dfs_pattern_detector *dpd, struct pulse_event *event)
 272{
 273        u32 i;
 274        struct channel_detector *cd;
 275
 276        /*
 277         * pulses received for a non-supported or un-initialized
 278         * domain are treated as detected radars for fail-safety
 279         */
 280        if (dpd->region == NL80211_DFS_UNSET)
 281                return true;
 282
 283        cd = channel_detector_get(dpd, event->freq);
 284        if (cd == NULL)
 285                return false;
 286
 287        /* reset detector on time stamp wraparound, caused by TSF reset */
 288        if (event->ts < dpd->last_pulse_ts)
 289                dpd_reset(dpd);
 290        dpd->last_pulse_ts = event->ts;
 291
 292        /* do type individual pattern matching */
 293        for (i = 0; i < dpd->num_radar_types; i++) {
 294                struct pri_detector *pd = cd->detectors[i];
 295                struct pri_sequence *ps = pd->add_pulse(pd, event);
 296                if (ps != NULL) {
 297                        ath_dbg(dpd->common, DFS,
 298                                "DFS: radar found on freq=%d: id=%d, pri=%d, "
 299                                "count=%d, count_false=%d\n",
 300                                event->freq, pd->rs->type_id,
 301                                ps->pri, ps->count, ps->count_falses);
 302                        pd->reset(pd, dpd->last_pulse_ts);
 303                        return true;
 304                }
 305        }
 306        return false;
 307}
 308
 309static struct ath_dfs_pool_stats
 310dpd_get_stats(struct dfs_pattern_detector *dpd)
 311{
 312        return global_dfs_pool_stats;
 313}
 314
 315static bool dpd_set_domain(struct dfs_pattern_detector *dpd,
 316                           enum nl80211_dfs_regions region)
 317{
 318        const struct radar_types *rt;
 319        struct channel_detector *cd, *cd0;
 320
 321        if (dpd->region == region)
 322                return true;
 323
 324        dpd->region = NL80211_DFS_UNSET;
 325
 326        rt = get_dfs_domain_radar_types(region);
 327        if (rt == NULL)
 328                return false;
 329
 330        /* delete all channel detectors for previous DFS domain */
 331        if (!list_empty(&dpd->channel_detectors))
 332                list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
 333                        channel_detector_exit(dpd, cd);
 334        dpd->radar_spec = rt->radar_types;
 335        dpd->num_radar_types = rt->num_radar_types;
 336
 337        dpd->region = region;
 338        return true;
 339}
 340
 341static const struct dfs_pattern_detector default_dpd = {
 342        .exit           = dpd_exit,
 343        .set_dfs_domain = dpd_set_domain,
 344        .add_pulse      = dpd_add_pulse,
 345        .get_stats      = dpd_get_stats,
 346        .region         = NL80211_DFS_UNSET,
 347};
 348
 349struct dfs_pattern_detector *
 350dfs_pattern_detector_init(struct ath_common *common,
 351                          enum nl80211_dfs_regions region)
 352{
 353        struct dfs_pattern_detector *dpd;
 354
 355        if (!IS_ENABLED(CONFIG_CFG80211_CERTIFICATION_ONUS))
 356                return NULL;
 357
 358        dpd = kmalloc(sizeof(*dpd), GFP_KERNEL);
 359        if (dpd == NULL)
 360                return NULL;
 361
 362        *dpd = default_dpd;
 363        INIT_LIST_HEAD(&dpd->channel_detectors);
 364
 365        dpd->common = common;
 366        if (dpd->set_dfs_domain(dpd, region))
 367                return dpd;
 368
 369        ath_dbg(common, DFS,"Could not set DFS domain to %d", region);
 370        kfree(dpd);
 371        return NULL;
 372}
 373EXPORT_SYMBOL(dfs_pattern_detector_init);
 374