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(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 */ 60 static 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 70 static 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 84 static 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 93 static 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 100 static 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 }; 111 112 static 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 }; 117 118 static 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 */ 129 static const struct radar_types * 130 get_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 */ 150 struct 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 */ 157 static 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 */ 168 static 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 } 183 184 static struct channel_detector * 185 channel_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; 210 211 fail: 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 */ 227 static struct channel_detector * 228 channel_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 */ 243 static 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 } 251 static 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 } 259 260 static bool 261 dpd_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 } 298 299 static struct ath_dfs_pool_stats 300 dpd_get_stats(struct dfs_pattern_detector *dpd) 301 { 302 return global_dfs_pool_stats; 303 } 304 305 static 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 } 330 331 static 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 }; 338 339 struct dfs_pattern_detector * 340 dfs_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 } 363 EXPORT_SYMBOL(dfs_pattern_detector_init); 364