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->bw = RATE_INFO_BW_5; 185 else if (IS_CHAN_HALF_RATE(ah->curchan)) 186 rxs->bw = RATE_INFO_BW_10; 187 188 if (rx_stats->rs_rate & 0x80) { 189 /* HT rate */ 190 rxs->encoding = RX_ENC_HT; 191 rxs->enc_flags |= rx_stats->enc_flags; 192 rxs->bw = rx_stats->bw; 193 rxs->rate_idx = rx_stats->rs_rate & 0x7f; 194 return 0; 195 } 196 197 for (i = 0; i < sband->n_bitrates; i++) { 198 if (sband->bitrates[i].hw_value == rx_stats->rs_rate) { 199 rxs->rate_idx = i; 200 return 0; 201 } 202 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) { 203 rxs->enc_flags |= RX_ENC_FLAG_SHORTPRE; 204 rxs->rate_idx = i; 205 return 0; 206 } 207 } 208 209 return -EINVAL; 210 } 211 EXPORT_SYMBOL(ath9k_cmn_process_rate); 212 213 void ath9k_cmn_process_rssi(struct ath_common *common, 214 struct ieee80211_hw *hw, 215 struct ath_rx_status *rx_stats, 216 struct ieee80211_rx_status *rxs) 217 { 218 struct ath_hw *ah = common->ah; 219 int last_rssi; 220 int rssi = rx_stats->rs_rssi; 221 int i, j; 222 223 /* 224 * RSSI is not available for subframes in an A-MPDU. 225 */ 226 if (rx_stats->rs_moreaggr) { 227 rxs->flag |= RX_FLAG_NO_SIGNAL_VAL; 228 return; 229 } 230 231 /* 232 * Check if the RSSI for the last subframe in an A-MPDU 233 * or an unaggregated frame is valid. 234 */ 235 if (rx_stats->rs_rssi == ATH9K_RSSI_BAD) { 236 rxs->flag |= RX_FLAG_NO_SIGNAL_VAL; 237 return; 238 } 239 240 for (i = 0, j = 0; i < ARRAY_SIZE(rx_stats->rs_rssi_ctl); i++) { 241 s8 rssi; 242 243 if (!(ah->rxchainmask & BIT(i))) 244 continue; 245 246 rssi = rx_stats->rs_rssi_ctl[i]; 247 if (rssi != ATH9K_RSSI_BAD) { 248 rxs->chains |= BIT(j); 249 rxs->chain_signal[j] = ah->noise + rssi; 250 } 251 j++; 252 } 253 254 /* 255 * Update Beacon RSSI, this is used by ANI. 256 */ 257 if (rx_stats->is_mybeacon && 258 ((ah->opmode == NL80211_IFTYPE_STATION) || 259 (ah->opmode == NL80211_IFTYPE_ADHOC))) { 260 ATH_RSSI_LPF(common->last_rssi, rx_stats->rs_rssi); 261 last_rssi = common->last_rssi; 262 263 if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER)) 264 rssi = ATH_EP_RND(last_rssi, ATH_RSSI_EP_MULTIPLIER); 265 if (rssi < 0) 266 rssi = 0; 267 268 ah->stats.avgbrssi = rssi; 269 } 270 271 rxs->signal = ah->noise + rx_stats->rs_rssi; 272 } 273 EXPORT_SYMBOL(ath9k_cmn_process_rssi); 274 275 int ath9k_cmn_get_hw_crypto_keytype(struct sk_buff *skb) 276 { 277 struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb); 278 279 if (tx_info->control.hw_key) { 280 switch (tx_info->control.hw_key->cipher) { 281 case WLAN_CIPHER_SUITE_WEP40: 282 case WLAN_CIPHER_SUITE_WEP104: 283 return ATH9K_KEY_TYPE_WEP; 284 case WLAN_CIPHER_SUITE_TKIP: 285 return ATH9K_KEY_TYPE_TKIP; 286 case WLAN_CIPHER_SUITE_CCMP: 287 return ATH9K_KEY_TYPE_AES; 288 default: 289 break; 290 } 291 } 292 293 return ATH9K_KEY_TYPE_CLEAR; 294 } 295 EXPORT_SYMBOL(ath9k_cmn_get_hw_crypto_keytype); 296 297 /* 298 * Update internal channel flags. 299 */ 300 static void ath9k_cmn_update_ichannel(struct ath9k_channel *ichan, 301 struct cfg80211_chan_def *chandef) 302 { 303 struct ieee80211_channel *chan = chandef->chan; 304 u16 flags = 0; 305 306 ichan->channel = chan->center_freq; 307 ichan->chan = chan; 308 309 if (chan->band == NL80211_BAND_5GHZ) 310 flags |= CHANNEL_5GHZ; 311 312 switch (chandef->width) { 313 case NL80211_CHAN_WIDTH_5: 314 flags |= CHANNEL_QUARTER; 315 break; 316 case NL80211_CHAN_WIDTH_10: 317 flags |= CHANNEL_HALF; 318 break; 319 case NL80211_CHAN_WIDTH_20_NOHT: 320 break; 321 case NL80211_CHAN_WIDTH_20: 322 flags |= CHANNEL_HT; 323 break; 324 case NL80211_CHAN_WIDTH_40: 325 if (chandef->center_freq1 > chandef->chan->center_freq) 326 flags |= CHANNEL_HT40PLUS | CHANNEL_HT; 327 else 328 flags |= CHANNEL_HT40MINUS | CHANNEL_HT; 329 break; 330 default: 331 WARN_ON(1); 332 } 333 334 ichan->channelFlags = flags; 335 } 336 337 /* 338 * Get the internal channel reference. 339 */ 340 struct ath9k_channel *ath9k_cmn_get_channel(struct ieee80211_hw *hw, 341 struct ath_hw *ah, 342 struct cfg80211_chan_def *chandef) 343 { 344 struct ieee80211_channel *curchan = chandef->chan; 345 struct ath9k_channel *channel; 346 347 channel = &ah->channels[curchan->hw_value]; 348 ath9k_cmn_update_ichannel(channel, chandef); 349 350 return channel; 351 } 352 EXPORT_SYMBOL(ath9k_cmn_get_channel); 353 354 int ath9k_cmn_count_streams(unsigned int chainmask, int max) 355 { 356 int streams = 0; 357 358 do { 359 if (++streams == max) 360 break; 361 } while ((chainmask = chainmask & (chainmask - 1))); 362 363 return streams; 364 } 365 EXPORT_SYMBOL(ath9k_cmn_count_streams); 366 367 void ath9k_cmn_update_txpow(struct ath_hw *ah, u16 cur_txpow, 368 u16 new_txpow, u16 *txpower) 369 { 370 struct ath_regulatory *reg = ath9k_hw_regulatory(ah); 371 372 if (reg->power_limit != new_txpow) 373 ath9k_hw_set_txpowerlimit(ah, new_txpow, false); 374 375 /* read back in case value is clamped */ 376 *txpower = reg->max_power_level; 377 } 378 EXPORT_SYMBOL(ath9k_cmn_update_txpow); 379 380 void ath9k_cmn_init_crypto(struct ath_hw *ah) 381 { 382 struct ath_common *common = ath9k_hw_common(ah); 383 int i = 0; 384 385 /* Get the hardware key cache size. */ 386 common->keymax = AR_KEYTABLE_SIZE; 387 388 /* 389 * Check whether the separate key cache entries 390 * are required to handle both tx+rx MIC keys. 391 * With split mic keys the number of stations is limited 392 * to 27 otherwise 59. 393 */ 394 if (ah->misc_mode & AR_PCU_MIC_NEW_LOC_ENA) 395 common->crypt_caps |= ATH_CRYPT_CAP_MIC_COMBINED; 396 397 /* 398 * Reset the key cache since some parts do not 399 * reset the contents on initial power up. 400 */ 401 for (i = 0; i < common->keymax; i++) 402 ath_hw_keyreset(common, (u16) i); 403 } 404 EXPORT_SYMBOL(ath9k_cmn_init_crypto); 405 406 static int __init ath9k_cmn_init(void) 407 { 408 return 0; 409 } 410 module_init(ath9k_cmn_init); 411 412 static void __exit ath9k_cmn_exit(void) 413 { 414 return; 415 } 416 module_exit(ath9k_cmn_exit); 417