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 */ 36 struct 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_RATE(PPB, RATE) ((PPB * RATE + 100 - RATE) / 100) 45 #define PPB_THRESH(PPB) PPB_THRESH_RATE(PPB, MIN_PPB_THRESH) 46 #define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF) 47 /* percentage of pulse width tolerance */ 48 #define WIDTH_TOLERANCE 5 49 #define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100) 50 #define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100) 51 52 #define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, CHIRP) \ 53 { \ 54 ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \ 55 (PRF2PRI(PMAX) - PRI_TOLERANCE), \ 56 (PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF, \ 57 PPB_THRESH(PPB), PRI_TOLERANCE, CHIRP \ 58 } 59 60 /* radar types as defined by ETSI EN-301-893 v1.5.1 */ 61 static const struct radar_detector_specs etsi_radar_ref_types_v15[] = { 62 ETSI_PATTERN(0, 0, 1, 700, 700, 1, 18, false), 63 ETSI_PATTERN(1, 0, 5, 200, 1000, 1, 10, false), 64 ETSI_PATTERN(2, 0, 15, 200, 1600, 1, 15, false), 65 ETSI_PATTERN(3, 0, 15, 2300, 4000, 1, 25, false), 66 ETSI_PATTERN(4, 20, 30, 2000, 4000, 1, 20, false), 67 ETSI_PATTERN(5, 0, 2, 300, 400, 3, 10, false), 68 ETSI_PATTERN(6, 0, 2, 400, 1200, 3, 15, false), 69 }; 70 71 static const struct radar_types etsi_radar_types_v15 = { 72 .region = NL80211_DFS_ETSI, 73 .num_radar_types = ARRAY_SIZE(etsi_radar_ref_types_v15), 74 .radar_types = etsi_radar_ref_types_v15, 75 }; 76 77 #define FCC_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, CHIRP) \ 78 { \ 79 ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \ 80 PMIN - PRI_TOLERANCE, \ 81 PMAX * PRF + PRI_TOLERANCE, PRF, PPB * PRF, \ 82 PPB_THRESH(PPB), PRI_TOLERANCE, CHIRP \ 83 } 84 85 /* radar types released on August 14, 2014 86 * type 1 PRI values randomly selected within the range of 518 and 3066. 87 * divide it to 3 groups is good enough for both of radar detection and 88 * avoiding false detection based on practical test results 89 * collected for more than a year. 90 */ 91 static const struct radar_detector_specs fcc_radar_ref_types[] = { 92 FCC_PATTERN(0, 0, 1, 1428, 1428, 1, 18, false), 93 FCC_PATTERN(101, 0, 1, 518, 938, 1, 57, false), 94 FCC_PATTERN(102, 0, 1, 938, 2000, 1, 27, false), 95 FCC_PATTERN(103, 0, 1, 2000, 3066, 1, 18, false), 96 FCC_PATTERN(2, 0, 5, 150, 230, 1, 23, false), 97 FCC_PATTERN(3, 6, 10, 200, 500, 1, 16, false), 98 FCC_PATTERN(4, 11, 20, 200, 500, 1, 12, false), 99 FCC_PATTERN(5, 50, 100, 1000, 2000, 1, 1, true), 100 FCC_PATTERN(6, 0, 1, 333, 333, 1, 9, false), 101 }; 102 103 static const struct radar_types fcc_radar_types = { 104 .region = NL80211_DFS_FCC, 105 .num_radar_types = ARRAY_SIZE(fcc_radar_ref_types), 106 .radar_types = fcc_radar_ref_types, 107 }; 108 109 #define JP_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB, RATE, CHIRP) \ 110 { \ 111 ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \ 112 PMIN - PRI_TOLERANCE, \ 113 PMAX * PRF + PRI_TOLERANCE, PRF, PPB * PRF, \ 114 PPB_THRESH_RATE(PPB, RATE), PRI_TOLERANCE, CHIRP \ 115 } 116 static const struct radar_detector_specs jp_radar_ref_types[] = { 117 JP_PATTERN(0, 0, 1, 1428, 1428, 1, 18, 29, false), 118 JP_PATTERN(1, 2, 3, 3846, 3846, 1, 18, 29, false), 119 JP_PATTERN(2, 0, 1, 1388, 1388, 1, 18, 50, false), 120 JP_PATTERN(3, 1, 2, 4000, 4000, 1, 18, 50, false), 121 JP_PATTERN(4, 0, 5, 150, 230, 1, 23, 50, false), 122 JP_PATTERN(5, 6, 10, 200, 500, 1, 16, 50, false), 123 JP_PATTERN(6, 11, 20, 200, 500, 1, 12, 50, false), 124 JP_PATTERN(7, 50, 100, 1000, 2000, 1, 20, 50, false), 125 JP_PATTERN(5, 0, 1, 333, 333, 1, 9, 50, false), 126 }; 127 128 static const struct radar_types jp_radar_types = { 129 .region = NL80211_DFS_JP, 130 .num_radar_types = ARRAY_SIZE(jp_radar_ref_types), 131 .radar_types = jp_radar_ref_types, 132 }; 133 134 static const struct radar_types *dfs_domains[] = { 135 &etsi_radar_types_v15, 136 &fcc_radar_types, 137 &jp_radar_types, 138 }; 139 140 /** 141 * get_dfs_domain_radar_types() - get radar types for a given DFS domain 142 * @param domain DFS domain 143 * @return radar_types ptr on success, NULL if DFS domain is not supported 144 */ 145 static const struct radar_types * 146 get_dfs_domain_radar_types(enum nl80211_dfs_regions region) 147 { 148 u32 i; 149 for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) { 150 if (dfs_domains[i]->region == region) 151 return dfs_domains[i]; 152 } 153 return NULL; 154 } 155 156 /** 157 * struct channel_detector - detector elements for a DFS channel 158 * @head: list_head 159 * @freq: frequency for this channel detector in MHz 160 * @detectors: array of dynamically created detector elements for this freq 161 * 162 * Channel detectors are required to provide multi-channel DFS detection, e.g. 163 * to support off-channel scanning. A pattern detector has a list of channels 164 * radar pulses have been reported for in the past. 165 */ 166 struct channel_detector { 167 struct list_head head; 168 u16 freq; 169 struct pri_detector **detectors; 170 }; 171 172 /* channel_detector_reset() - reset detector lines for a given channel */ 173 static void channel_detector_reset(struct dfs_pattern_detector *dpd, 174 struct channel_detector *cd) 175 { 176 u32 i; 177 if (cd == NULL) 178 return; 179 for (i = 0; i < dpd->num_radar_types; i++) 180 cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts); 181 } 182 183 /* channel_detector_exit() - destructor */ 184 static void channel_detector_exit(struct dfs_pattern_detector *dpd, 185 struct channel_detector *cd) 186 { 187 u32 i; 188 if (cd == NULL) 189 return; 190 list_del(&cd->head); 191 for (i = 0; i < dpd->num_radar_types; i++) { 192 struct pri_detector *de = cd->detectors[i]; 193 if (de != NULL) 194 de->exit(de); 195 } 196 kfree(cd->detectors); 197 kfree(cd); 198 } 199 200 static struct channel_detector * 201 channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq) 202 { 203 u32 sz, i; 204 struct channel_detector *cd; 205 206 cd = kmalloc(sizeof(*cd), GFP_ATOMIC); 207 if (cd == NULL) 208 goto fail; 209 210 INIT_LIST_HEAD(&cd->head); 211 cd->freq = freq; 212 sz = sizeof(cd->detectors) * dpd->num_radar_types; 213 cd->detectors = kzalloc(sz, GFP_ATOMIC); 214 if (cd->detectors == NULL) 215 goto fail; 216 217 for (i = 0; i < dpd->num_radar_types; i++) { 218 const struct radar_detector_specs *rs = &dpd->radar_spec[i]; 219 struct pri_detector *de = pri_detector_init(rs); 220 if (de == NULL) 221 goto fail; 222 cd->detectors[i] = de; 223 } 224 list_add(&cd->head, &dpd->channel_detectors); 225 return cd; 226 227 fail: 228 ath_dbg(dpd->common, DFS, 229 "failed to allocate channel_detector for freq=%d\n", freq); 230 channel_detector_exit(dpd, cd); 231 return NULL; 232 } 233 234 /** 235 * channel_detector_get() - get channel detector for given frequency 236 * @param dpd instance pointer 237 * @param freq frequency in MHz 238 * @return pointer to channel detector on success, NULL otherwise 239 * 240 * Return existing channel detector for the given frequency or return a 241 * newly create one. 242 */ 243 static struct channel_detector * 244 channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq) 245 { 246 struct channel_detector *cd; 247 list_for_each_entry(cd, &dpd->channel_detectors, head) { 248 if (cd->freq == freq) 249 return cd; 250 } 251 return channel_detector_create(dpd, freq); 252 } 253 254 /* 255 * DFS Pattern Detector 256 */ 257 258 /* dpd_reset(): reset all channel detectors */ 259 static void dpd_reset(struct dfs_pattern_detector *dpd) 260 { 261 struct channel_detector *cd; 262 if (!list_empty(&dpd->channel_detectors)) 263 list_for_each_entry(cd, &dpd->channel_detectors, head) 264 channel_detector_reset(dpd, cd); 265 266 } 267 static void dpd_exit(struct dfs_pattern_detector *dpd) 268 { 269 struct channel_detector *cd, *cd0; 270 if (!list_empty(&dpd->channel_detectors)) 271 list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) 272 channel_detector_exit(dpd, cd); 273 kfree(dpd); 274 } 275 276 static bool 277 dpd_add_pulse(struct dfs_pattern_detector *dpd, struct pulse_event *event) 278 { 279 u32 i; 280 struct channel_detector *cd; 281 282 /* 283 * pulses received for a non-supported or un-initialized 284 * domain are treated as detected radars for fail-safety 285 */ 286 if (dpd->region == NL80211_DFS_UNSET) 287 return true; 288 289 cd = channel_detector_get(dpd, event->freq); 290 if (cd == NULL) 291 return false; 292 293 dpd->last_pulse_ts = event->ts; 294 /* reset detector on time stamp wraparound, caused by TSF reset */ 295 if (event->ts < dpd->last_pulse_ts) 296 dpd_reset(dpd); 297 298 /* do type individual pattern matching */ 299 for (i = 0; i < dpd->num_radar_types; i++) { 300 struct pri_detector *pd = cd->detectors[i]; 301 struct pri_sequence *ps = pd->add_pulse(pd, event); 302 if (ps != NULL) { 303 ath_dbg(dpd->common, DFS, 304 "DFS: radar found on freq=%d: id=%d, pri=%d, " 305 "count=%d, count_false=%d\n", 306 event->freq, pd->rs->type_id, 307 ps->pri, ps->count, ps->count_falses); 308 pd->reset(pd, dpd->last_pulse_ts); 309 return true; 310 } 311 } 312 return false; 313 } 314 315 static struct ath_dfs_pool_stats 316 dpd_get_stats(struct dfs_pattern_detector *dpd) 317 { 318 return global_dfs_pool_stats; 319 } 320 321 static bool dpd_set_domain(struct dfs_pattern_detector *dpd, 322 enum nl80211_dfs_regions region) 323 { 324 const struct radar_types *rt; 325 struct channel_detector *cd, *cd0; 326 327 if (dpd->region == region) 328 return true; 329 330 dpd->region = NL80211_DFS_UNSET; 331 332 rt = get_dfs_domain_radar_types(region); 333 if (rt == NULL) 334 return false; 335 336 /* delete all channel detectors for previous DFS domain */ 337 if (!list_empty(&dpd->channel_detectors)) 338 list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) 339 channel_detector_exit(dpd, cd); 340 dpd->radar_spec = rt->radar_types; 341 dpd->num_radar_types = rt->num_radar_types; 342 343 dpd->region = region; 344 return true; 345 } 346 347 static struct dfs_pattern_detector default_dpd = { 348 .exit = dpd_exit, 349 .set_dfs_domain = dpd_set_domain, 350 .add_pulse = dpd_add_pulse, 351 .get_stats = dpd_get_stats, 352 .region = NL80211_DFS_UNSET, 353 }; 354 355 struct dfs_pattern_detector * 356 dfs_pattern_detector_init(struct ath_common *common, 357 enum nl80211_dfs_regions region) 358 { 359 struct dfs_pattern_detector *dpd; 360 361 if (!config_enabled(CONFIG_CFG80211_CERTIFICATION_ONUS)) 362 return NULL; 363 364 dpd = kmalloc(sizeof(*dpd), GFP_KERNEL); 365 if (dpd == NULL) 366 return NULL; 367 368 *dpd = default_dpd; 369 INIT_LIST_HEAD(&dpd->channel_detectors); 370 371 dpd->common = common; 372 if (dpd->set_dfs_domain(dpd, region)) 373 return dpd; 374 375 ath_dbg(common, DFS,"Could not set DFS domain to %d", region); 376 kfree(dpd); 377 return NULL; 378 } 379 EXPORT_SYMBOL(dfs_pattern_detector_init); 380