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1/*2 * Copyright (c) 2009-2011 Atheros Communications Inc.3 *4 * Permission to use, copy, modify, and/or distribute this software for any5 * purpose with or without fee is hereby granted, provided that the above6 * copyright notice and this permission notice appear in all copies.7 *8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.15 */16 17/*18 * Module for common driver code between ath9k and ath9k_htc19 */20 21#include <linux/kernel.h>22#include <linux/module.h>23 24#include "common.h"25 26MODULE_AUTHOR("Atheros Communications");27MODULE_DESCRIPTION("Shared library for Atheros wireless 802.11n LAN cards.");28MODULE_LICENSE("Dual BSD/GPL");29 30/* Assumes you've already done the endian to CPU conversion */31bool 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 the55 * descriptor does contain a valid key index. This has been observed56 * 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 the69 * chained descriptors so it can be ignored if rs_more is set. The70 * rs_more will be false at the last element of the chained71 * 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 of90 * 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 verification107 * 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}116EXPORT_SYMBOL(ath9k_cmn_rx_accept);117 118void 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 the137 * packet payload is non-zero. The general calculation for138 * padsize would take into account odd header lengths:139 * padsize = (4 - padpos % 4) % 4; However, since only140 * even-length headers are used, padding can only be 0 or 2141 * bytes and we can optimize this a bit. In addition, we must142 * not try to remove padding from short control frames that do143 * 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}168EXPORT_SYMBOL(ath9k_cmn_rx_skb_postprocess);169 170int 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}211EXPORT_SYMBOL(ath9k_cmn_process_rate);212 213void 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-MPDU233 * 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}273EXPORT_SYMBOL(ath9k_cmn_process_rssi);274 275int 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}295EXPORT_SYMBOL(ath9k_cmn_get_hw_crypto_keytype);296 297/*298 * Update internal channel flags.299 */300static 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 else328 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 */340struct 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}352EXPORT_SYMBOL(ath9k_cmn_get_channel);353 354int 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}365EXPORT_SYMBOL(ath9k_cmn_count_streams);366 367void 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 (ah->curchan && 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}378EXPORT_SYMBOL(ath9k_cmn_update_txpow);379 380void 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 entries390 * are required to handle both tx+rx MIC keys.391 * With split mic keys the number of stations is limited392 * 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 not399 * reset the contents on initial power up.400 */401 for (i = 0; i < common->keymax; i++)402 ath_hw_keyreset(common, (u16) i);403}404EXPORT_SYMBOL(ath9k_cmn_init_crypto);405 406static int __init ath9k_cmn_init(void)407{408 return 0;409}410module_init(ath9k_cmn_init);411 412static void __exit ath9k_cmn_exit(void)413{414 return;415}416module_exit(ath9k_cmn_exit);417