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
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(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}
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 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, len: 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-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}
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 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 */
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(ichan: 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, limit: new_txpow, test: 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 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, entry: (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

source code of linux/drivers/net/wireless/ath/ath9k/common.c