1 /* 2 * Copyright (c) 2009-2011 Atheros Communications Inc. 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 /* 18 * Module for common driver code between ath9k and ath9k_htc 19 */ 20 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 24 #include "common.h" 25 26 MODULE_AUTHOR("Atheros Communications"); 27 MODULE_DESCRIPTION("Shared library for Atheros wireless 802.11n LAN cards."); 28 MODULE_LICENSE("Dual BSD/GPL"); 29 30 /* Assumes you've already done the endian to CPU conversion */ 31 bool ath9k_cmn_rx_accept(struct ath_common *common, 32 struct ieee80211_hdr *hdr, 33 struct ieee80211_rx_status *rxs, 34 struct ath_rx_status *rx_stats, 35 bool *decrypt_error, 36 unsigned int rxfilter) 37 { 38 struct ath_hw *ah = common->ah; 39 bool is_mc, is_valid_tkip, strip_mic, mic_error; 40 __le16 fc; 41 42 fc = hdr->frame_control; 43 44 is_mc = !!is_multicast_ether_addr(hdr->addr1); 45 is_valid_tkip = rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID && 46 test_bit(rx_stats->rs_keyix, common->tkip_keymap); 47 strip_mic = is_valid_tkip && ieee80211_is_data(fc) && 48 ieee80211_has_protected(fc) && 49 !(rx_stats->rs_status & 50 (ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC | ATH9K_RXERR_MIC | 51 ATH9K_RXERR_KEYMISS)); 52 53 /* 54 * Key miss events are only relevant for pairwise keys where the 55 * descriptor does contain a valid key index. This has been observed 56 * mostly with CCMP encryption. 57 */ 58 if (rx_stats->rs_keyix == ATH9K_RXKEYIX_INVALID || 59 !test_bit(rx_stats->rs_keyix, common->ccmp_keymap)) 60 rx_stats->rs_status &= ~ATH9K_RXERR_KEYMISS; 61 62 mic_error = is_valid_tkip && !ieee80211_is_ctl(fc) && 63 !ieee80211_has_morefrags(fc) && 64 !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) && 65 (rx_stats->rs_status & ATH9K_RXERR_MIC); 66 67 /* 68 * The rx_stats->rs_status will not be set until the end of the 69 * chained descriptors so it can be ignored if rs_more is set. The 70 * rs_more will be false at the last element of the chained 71 * descriptors. 72 */ 73 if (rx_stats->rs_status != 0) { 74 u8 status_mask; 75 76 if (rx_stats->rs_status & ATH9K_RXERR_CRC) { 77 rxs->flag |= RX_FLAG_FAILED_FCS_CRC; 78 mic_error = false; 79 } 80 81 if ((rx_stats->rs_status & ATH9K_RXERR_DECRYPT) || 82 (!is_mc && (rx_stats->rs_status & ATH9K_RXERR_KEYMISS))) { 83 *decrypt_error = true; 84 mic_error = false; 85 } 86 87 88 /* 89 * Reject error frames with the exception of 90 * decryption and MIC failures. For monitor mode, 91 * we also ignore the CRC error. 92 */ 93 status_mask = ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC | 94 ATH9K_RXERR_KEYMISS; 95 96 if (ah->is_monitoring && (rxfilter & FIF_FCSFAIL)) 97 status_mask |= ATH9K_RXERR_CRC; 98 99 if (rx_stats->rs_status & ~status_mask) 100 return false; 101 } 102 103 /* 104 * For unicast frames the MIC error bit can have false positives, 105 * so all MIC error reports need to be validated in software. 106 * False negatives are not common, so skip software verification 107 * if the hardware considers the MIC valid. 108 */ 109 if (strip_mic) 110 rxs->flag |= RX_FLAG_MMIC_STRIPPED; 111 else if (is_mc && mic_error) 112 rxs->flag |= RX_FLAG_MMIC_ERROR; 113 114 return true; 115 } 116 EXPORT_SYMBOL(ath9k_cmn_rx_accept); 117 118 void ath9k_cmn_rx_skb_postprocess(struct ath_common *common, 119 struct sk_buff *skb, 120 struct ath_rx_status *rx_stats, 121 struct ieee80211_rx_status *rxs, 122 bool decrypt_error) 123 { 124 struct ath_hw *ah = common->ah; 125 struct ieee80211_hdr *hdr; 126 int hdrlen, padpos, padsize; 127 u8 keyix; 128 __le16 fc; 129 130 /* see if any padding is done by the hw and remove it */ 131 hdr = (struct ieee80211_hdr *) skb->data; 132 hdrlen = ieee80211_get_hdrlen_from_skb(skb); 133 fc = hdr->frame_control; 134 padpos = ieee80211_hdrlen(fc); 135 136 /* The MAC header is padded to have 32-bit boundary if the 137 * packet payload is non-zero. The general calculation for 138 * padsize would take into account odd header lengths: 139 * padsize = (4 - padpos % 4) % 4; However, since only 140 * even-length headers are used, padding can only be 0 or 2 141 * bytes and we can optimize this a bit. In addition, we must 142 * not try to remove padding from short control frames that do 143 * not have payload. */ 144 padsize = padpos & 3; 145 if (padsize && skb->len>=padpos+padsize+FCS_LEN) { 146 memmove(skb->data + padsize, skb->data, padpos); 147 skb_pull(skb, padsize); 148 } 149 150 keyix = rx_stats->rs_keyix; 151 152 if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error && 153 ieee80211_has_protected(fc)) { 154 rxs->flag |= RX_FLAG_DECRYPTED; 155 } else if (ieee80211_has_protected(fc) 156 && !decrypt_error && skb->len >= hdrlen + 4) { 157 keyix = skb->data[hdrlen + 3] >> 6; 158 159 if (test_bit(keyix, common->keymap)) 160 rxs->flag |= RX_FLAG_DECRYPTED; 161 } 162 if (ah->sw_mgmt_crypto_rx && 163 (rxs->flag & RX_FLAG_DECRYPTED) && 164 ieee80211_is_mgmt(fc)) 165 /* Use software decrypt for management frames. */ 166 rxs->flag &= ~RX_FLAG_DECRYPTED; 167 } 168 EXPORT_SYMBOL(ath9k_cmn_rx_skb_postprocess); 169 170 int ath9k_cmn_process_rate(struct ath_common *common, 171 struct ieee80211_hw *hw, 172 struct ath_rx_status *rx_stats, 173 struct ieee80211_rx_status *rxs) 174 { 175 struct ieee80211_supported_band *sband; 176 enum nl80211_band band; 177 unsigned int i = 0; 178 struct ath_hw *ah = common->ah; 179 180 band = ah->curchan->chan->band; 181 sband = hw->wiphy->bands[band]; 182 183 if (IS_CHAN_QUARTER_RATE(ah->curchan)) 184 rxs->flag |= RX_FLAG_5MHZ; 185 else if (IS_CHAN_HALF_RATE(ah->curchan)) 186 rxs->flag |= RX_FLAG_10MHZ; 187 188 if (rx_stats->rs_rate & 0x80) { 189 /* HT rate */ 190 rxs->flag |= RX_FLAG_HT; 191 rxs->flag |= rx_stats->flag; 192 rxs->rate_idx = rx_stats->rs_rate & 0x7f; 193 return 0; 194 } 195 196 for (i = 0; i < sband->n_bitrates; i++) { 197 if (sband->bitrates[i].hw_value == rx_stats->rs_rate) { 198 rxs->rate_idx = i; 199 return 0; 200 } 201 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) { 202 rxs->flag |= RX_FLAG_SHORTPRE; 203 rxs->rate_idx = i; 204 return 0; 205 } 206 } 207 208 return -EINVAL; 209 } 210 EXPORT_SYMBOL(ath9k_cmn_process_rate); 211 212 void ath9k_cmn_process_rssi(struct ath_common *common, 213 struct ieee80211_hw *hw, 214 struct ath_rx_status *rx_stats, 215 struct ieee80211_rx_status *rxs) 216 { 217 struct ath_hw *ah = common->ah; 218 int last_rssi; 219 int rssi = rx_stats->rs_rssi; 220 int i, j; 221 222 /* 223 * RSSI is not available for subframes in an A-MPDU. 224 */ 225 if (rx_stats->rs_moreaggr) { 226 rxs->flag |= RX_FLAG_NO_SIGNAL_VAL; 227 return; 228 } 229 230 /* 231 * Check if the RSSI for the last subframe in an A-MPDU 232 * or an unaggregated frame is valid. 233 */ 234 if (rx_stats->rs_rssi == ATH9K_RSSI_BAD) { 235 rxs->flag |= RX_FLAG_NO_SIGNAL_VAL; 236 return; 237 } 238 239 for (i = 0, j = 0; i < ARRAY_SIZE(rx_stats->rs_rssi_ctl); i++) { 240 s8 rssi; 241 242 if (!(ah->rxchainmask & BIT(i))) 243 continue; 244 245 rssi = rx_stats->rs_rssi_ctl[i]; 246 if (rssi != ATH9K_RSSI_BAD) { 247 rxs->chains |= BIT(j); 248 rxs->chain_signal[j] = ah->noise + rssi; 249 } 250 j++; 251 } 252 253 /* 254 * Update Beacon RSSI, this is used by ANI. 255 */ 256 if (rx_stats->is_mybeacon && 257 ((ah->opmode == NL80211_IFTYPE_STATION) || 258 (ah->opmode == NL80211_IFTYPE_ADHOC))) { 259 ATH_RSSI_LPF(common->last_rssi, rx_stats->rs_rssi); 260 last_rssi = common->last_rssi; 261 262 if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER)) 263 rssi = ATH_EP_RND(last_rssi, ATH_RSSI_EP_MULTIPLIER); 264 if (rssi < 0) 265 rssi = 0; 266 267 ah->stats.avgbrssi = rssi; 268 } 269 270 rxs->signal = ah->noise + rx_stats->rs_rssi; 271 } 272 EXPORT_SYMBOL(ath9k_cmn_process_rssi); 273 274 int ath9k_cmn_get_hw_crypto_keytype(struct sk_buff *skb) 275 { 276 struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb); 277 278 if (tx_info->control.hw_key) { 279 switch (tx_info->control.hw_key->cipher) { 280 case WLAN_CIPHER_SUITE_WEP40: 281 case WLAN_CIPHER_SUITE_WEP104: 282 return ATH9K_KEY_TYPE_WEP; 283 case WLAN_CIPHER_SUITE_TKIP: 284 return ATH9K_KEY_TYPE_TKIP; 285 case WLAN_CIPHER_SUITE_CCMP: 286 return ATH9K_KEY_TYPE_AES; 287 default: 288 break; 289 } 290 } 291 292 return ATH9K_KEY_TYPE_CLEAR; 293 } 294 EXPORT_SYMBOL(ath9k_cmn_get_hw_crypto_keytype); 295 296 /* 297 * Update internal channel flags. 298 */ 299 static void ath9k_cmn_update_ichannel(struct ath9k_channel *ichan, 300 struct cfg80211_chan_def *chandef) 301 { 302 struct ieee80211_channel *chan = chandef->chan; 303 u16 flags = 0; 304 305 ichan->channel = chan->center_freq; 306 ichan->chan = chan; 307 308 if (chan->band == NL80211_BAND_5GHZ) 309 flags |= CHANNEL_5GHZ; 310 311 switch (chandef->width) { 312 case NL80211_CHAN_WIDTH_5: 313 flags |= CHANNEL_QUARTER; 314 break; 315 case NL80211_CHAN_WIDTH_10: 316 flags |= CHANNEL_HALF; 317 break; 318 case NL80211_CHAN_WIDTH_20_NOHT: 319 break; 320 case NL80211_CHAN_WIDTH_20: 321 flags |= CHANNEL_HT; 322 break; 323 case NL80211_CHAN_WIDTH_40: 324 if (chandef->center_freq1 > chandef->chan->center_freq) 325 flags |= CHANNEL_HT40PLUS | CHANNEL_HT; 326 else 327 flags |= CHANNEL_HT40MINUS | CHANNEL_HT; 328 break; 329 default: 330 WARN_ON(1); 331 } 332 333 ichan->channelFlags = flags; 334 } 335 336 /* 337 * Get the internal channel reference. 338 */ 339 struct ath9k_channel *ath9k_cmn_get_channel(struct ieee80211_hw *hw, 340 struct ath_hw *ah, 341 struct cfg80211_chan_def *chandef) 342 { 343 struct ieee80211_channel *curchan = chandef->chan; 344 struct ath9k_channel *channel; 345 346 channel = &ah->channels[curchan->hw_value]; 347 ath9k_cmn_update_ichannel(channel, chandef); 348 349 return channel; 350 } 351 EXPORT_SYMBOL(ath9k_cmn_get_channel); 352 353 int ath9k_cmn_count_streams(unsigned int chainmask, int max) 354 { 355 int streams = 0; 356 357 do { 358 if (++streams == max) 359 break; 360 } while ((chainmask = chainmask & (chainmask - 1))); 361 362 return streams; 363 } 364 EXPORT_SYMBOL(ath9k_cmn_count_streams); 365 366 void ath9k_cmn_update_txpow(struct ath_hw *ah, u16 cur_txpow, 367 u16 new_txpow, u16 *txpower) 368 { 369 struct ath_regulatory *reg = ath9k_hw_regulatory(ah); 370 371 if (reg->power_limit != new_txpow) 372 ath9k_hw_set_txpowerlimit(ah, new_txpow, false); 373 374 /* read back in case value is clamped */ 375 *txpower = reg->max_power_level; 376 } 377 EXPORT_SYMBOL(ath9k_cmn_update_txpow); 378 379 void ath9k_cmn_init_crypto(struct ath_hw *ah) 380 { 381 struct ath_common *common = ath9k_hw_common(ah); 382 int i = 0; 383 384 /* Get the hardware key cache size. */ 385 common->keymax = AR_KEYTABLE_SIZE; 386 387 /* 388 * Check whether the separate key cache entries 389 * are required to handle both tx+rx MIC keys. 390 * With split mic keys the number of stations is limited 391 * to 27 otherwise 59. 392 */ 393 if (ah->misc_mode & AR_PCU_MIC_NEW_LOC_ENA) 394 common->crypt_caps |= ATH_CRYPT_CAP_MIC_COMBINED; 395 396 /* 397 * Reset the key cache since some parts do not 398 * reset the contents on initial power up. 399 */ 400 for (i = 0; i < common->keymax; i++) 401 ath_hw_keyreset(common, (u16) i); 402 } 403 EXPORT_SYMBOL(ath9k_cmn_init_crypto); 404 405 static int __init ath9k_cmn_init(void) 406 { 407 return 0; 408 } 409 module_init(ath9k_cmn_init); 410 411 static void __exit ath9k_cmn_exit(void) 412 { 413 return; 414 } 415 module_exit(ath9k_cmn_exit); 416