summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/ath/ath9k/common.c
blob: 33b0c7aef2ea39f527962f483a8014a052ac10ce (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
/*
 * Copyright (c) 2009-2011 Atheros Communications Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * Module for common driver code between ath9k and ath9k_htc
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "common.h"

MODULE_AUTHOR("Atheros Communications");
MODULE_DESCRIPTION("Shared library for Atheros wireless 802.11n LAN cards.");
MODULE_LICENSE("Dual BSD/GPL");

/* Assumes you've already done the endian to CPU conversion */
bool ath9k_cmn_rx_accept(struct ath_common *common,
			 struct ieee80211_hdr *hdr,
			 struct ieee80211_rx_status *rxs,
			 struct ath_rx_status *rx_stats,
			 bool *decrypt_error,
			 unsigned int rxfilter)
{
	struct ath_hw *ah = common->ah;
	bool is_mc, is_valid_tkip, strip_mic, mic_error;
	__le16 fc;

	fc = hdr->frame_control;

	is_mc = !!is_multicast_ether_addr(hdr->addr1);
	is_valid_tkip = rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID &&
		test_bit(rx_stats->rs_keyix, common->tkip_keymap);
	strip_mic = is_valid_tkip && ieee80211_is_data(fc) &&
		ieee80211_has_protected(fc) &&
		!(rx_stats->rs_status &
		(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC | ATH9K_RXERR_MIC |
		 ATH9K_RXERR_KEYMISS));

	/*
	 * Key miss events are only relevant for pairwise keys where the
	 * descriptor does contain a valid key index. This has been observed
	 * mostly with CCMP encryption.
	 */
	if (rx_stats->rs_keyix == ATH9K_RXKEYIX_INVALID ||
	    !test_bit(rx_stats->rs_keyix, common->ccmp_keymap))
		rx_stats->rs_status &= ~ATH9K_RXERR_KEYMISS;

	mic_error = is_valid_tkip && !ieee80211_is_ctl(fc) &&
		!ieee80211_has_morefrags(fc) &&
		!(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
		(rx_stats->rs_status & ATH9K_RXERR_MIC);

	/*
	 * The rx_stats->rs_status will not be set until the end of the
	 * chained descriptors so it can be ignored if rs_more is set. The
	 * rs_more will be false at the last element of the chained
	 * descriptors.
	 */
	if (rx_stats->rs_status != 0) {
		u8 status_mask;

		if (rx_stats->rs_status & ATH9K_RXERR_CRC) {
			rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
			mic_error = false;
		}

		if ((rx_stats->rs_status & ATH9K_RXERR_DECRYPT) ||
		    (!is_mc && (rx_stats->rs_status & ATH9K_RXERR_KEYMISS))) {
			*decrypt_error = true;
			mic_error = false;
		}


		/*
		 * Reject error frames with the exception of
		 * decryption and MIC failures. For monitor mode,
		 * we also ignore the CRC error.
		 */
		status_mask = ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
			      ATH9K_RXERR_KEYMISS;

		if (ah->is_monitoring && (rxfilter & FIF_FCSFAIL))
			status_mask |= ATH9K_RXERR_CRC;

		if (rx_stats->rs_status & ~status_mask)
			return false;
	}

	/*
	 * For unicast frames the MIC error bit can have false positives,
	 * so all MIC error reports need to be validated in software.
	 * False negatives are not common, so skip software verification
	 * if the hardware considers the MIC valid.
	 */
	if (strip_mic)
		rxs->flag |= RX_FLAG_MMIC_STRIPPED;
	else if (is_mc && mic_error)
		rxs->flag |= RX_FLAG_MMIC_ERROR;

	return true;
}
EXPORT_SYMBOL(ath9k_cmn_rx_accept);

void ath9k_cmn_rx_skb_postprocess(struct ath_common *common,
				  struct sk_buff *skb,
				  struct ath_rx_status *rx_stats,
				  struct ieee80211_rx_status *rxs,
				  bool decrypt_error)
{
	struct ath_hw *ah = common->ah;
	struct ieee80211_hdr *hdr;
	int hdrlen, padpos, padsize;
	u8 keyix;
	__le16 fc;

	/* see if any padding is done by the hw and remove it */
	hdr = (struct ieee80211_hdr *) skb->data;
	hdrlen = ieee80211_get_hdrlen_from_skb(skb);
	fc = hdr->frame_control;
	padpos = ieee80211_hdrlen(fc);

	/* The MAC header is padded to have 32-bit boundary if the
	 * packet payload is non-zero. The general calculation for
	 * padsize would take into account odd header lengths:
	 * padsize = (4 - padpos % 4) % 4; However, since only
	 * even-length headers are used, padding can only be 0 or 2
	 * bytes and we can optimize this a bit. In addition, we must
	 * not try to remove padding from short control frames that do
	 * not have payload. */
	padsize = padpos & 3;
	if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
		memmove(skb->data + padsize, skb->data, padpos);
		skb_pull(skb, padsize);
	}

	keyix = rx_stats->rs_keyix;

	if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
	    ieee80211_has_protected(fc)) {
		rxs->flag |= RX_FLAG_DECRYPTED;
	} else if (ieee80211_has_protected(fc)
		   && !decrypt_error && skb->len >= hdrlen + 4) {
		keyix = skb->data[hdrlen + 3] >> 6;

		if (test_bit(keyix, common->keymap))
			rxs->flag |= RX_FLAG_DECRYPTED;
	}
	if (ah->sw_mgmt_crypto &&
	    (rxs->flag & RX_FLAG_DECRYPTED) &&
	    ieee80211_is_mgmt(fc))
		/* Use software decrypt for management frames. */
		rxs->flag &= ~RX_FLAG_DECRYPTED;
}
EXPORT_SYMBOL(ath9k_cmn_rx_skb_postprocess);

int ath9k_cmn_process_rate(struct ath_common *common,
			   struct ieee80211_hw *hw,
			   struct ath_rx_status *rx_stats,
			   struct ieee80211_rx_status *rxs)
{
	struct ieee80211_supported_band *sband;
	enum ieee80211_band band;
	unsigned int i = 0;
	struct ath_hw *ah = common->ah;

	band = ah->curchan->chan->band;
	sband = hw->wiphy->bands[band];

	if (IS_CHAN_QUARTER_RATE(ah->curchan))
		rxs->flag |= RX_FLAG_5MHZ;
	else if (IS_CHAN_HALF_RATE(ah->curchan))
		rxs->flag |= RX_FLAG_10MHZ;

	if (rx_stats->rs_rate & 0x80) {
		/* HT rate */
		rxs->flag |= RX_FLAG_HT;
		rxs->flag |= rx_stats->flag;
		rxs->rate_idx = rx_stats->rs_rate & 0x7f;
		return 0;
	}

	for (i = 0; i < sband->n_bitrates; i++) {
		if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
			rxs->rate_idx = i;
			return 0;
		}
		if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
			rxs->flag |= RX_FLAG_SHORTPRE;
			rxs->rate_idx = i;
			return 0;
		}
	}

	return -EINVAL;
}
EXPORT_SYMBOL(ath9k_cmn_process_rate);

void ath9k_cmn_process_rssi(struct ath_common *common,
			    struct ieee80211_hw *hw,
			    struct ath_rx_status *rx_stats,
			    struct ieee80211_rx_status *rxs)
{
	struct ath_hw *ah = common->ah;
	int last_rssi;
	int rssi = rx_stats->rs_rssi;
	int i, j;

	/*
	 * RSSI is not available for subframes in an A-MPDU.
	 */
	if (rx_stats->rs_moreaggr) {
		rxs->flag |= RX_FLAG_NO_SIGNAL_VAL;
		return;
	}

	/*
	 * Check if the RSSI for the last subframe in an A-MPDU
	 * or an unaggregated frame is valid.
	 */
	if (rx_stats->rs_rssi == ATH9K_RSSI_BAD) {
		rxs->flag |= RX_FLAG_NO_SIGNAL_VAL;
		return;
	}

	for (i = 0, j = 0; i < ARRAY_SIZE(rx_stats->rs_rssi_ctl); i++) {
		s8 rssi;

		if (!(ah->rxchainmask & BIT(i)))
			continue;

		rssi = rx_stats->rs_rssi_ctl[i];
		if (rssi != ATH9K_RSSI_BAD) {
		    rxs->chains |= BIT(j);
		    rxs->chain_signal[j] = ah->noise + rssi;
		}
		j++;
	}

	/*
	 * Update Beacon RSSI, this is used by ANI.
	 */
	if (rx_stats->is_mybeacon &&
	    ((ah->opmode == NL80211_IFTYPE_STATION) ||
	     (ah->opmode == NL80211_IFTYPE_ADHOC))) {
		ATH_RSSI_LPF(common->last_rssi, rx_stats->rs_rssi);
		last_rssi = common->last_rssi;

		if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
			rssi = ATH_EP_RND(last_rssi, ATH_RSSI_EP_MULTIPLIER);
		if (rssi < 0)
			rssi = 0;

		ah->stats.avgbrssi = rssi;
	}

	rxs->signal = ah->noise + rx_stats->rs_rssi;
}
EXPORT_SYMBOL(ath9k_cmn_process_rssi);

int ath9k_cmn_get_hw_crypto_keytype(struct sk_buff *skb)
{
	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);

	if (tx_info->control.hw_key) {
		switch (tx_info->control.hw_key->cipher) {
		case WLAN_CIPHER_SUITE_WEP40:
		case WLAN_CIPHER_SUITE_WEP104:
			return ATH9K_KEY_TYPE_WEP;
		case WLAN_CIPHER_SUITE_TKIP:
			return ATH9K_KEY_TYPE_TKIP;
		case WLAN_CIPHER_SUITE_CCMP:
			return ATH9K_KEY_TYPE_AES;
		default:
			break;
		}
	}

	return ATH9K_KEY_TYPE_CLEAR;
}
EXPORT_SYMBOL(ath9k_cmn_get_hw_crypto_keytype);

/*
 * Update internal channel flags.
 */
static void ath9k_cmn_update_ichannel(struct ath9k_channel *ichan,
				      struct cfg80211_chan_def *chandef)
{
	struct ieee80211_channel *chan = chandef->chan;
	u16 flags = 0;

	ichan->channel = chan->center_freq;
	ichan->chan = chan;

	if (chan->band == IEEE80211_BAND_5GHZ)
		flags |= CHANNEL_5GHZ;

	switch (chandef->width) {
	case NL80211_CHAN_WIDTH_5:
		flags |= CHANNEL_QUARTER;
		break;
	case NL80211_CHAN_WIDTH_10:
		flags |= CHANNEL_HALF;
		break;
	case NL80211_CHAN_WIDTH_20_NOHT:
		break;
	case NL80211_CHAN_WIDTH_20:
		flags |= CHANNEL_HT;
		break;
	case NL80211_CHAN_WIDTH_40:
		if (chandef->center_freq1 > chandef->chan->center_freq)
			flags |= CHANNEL_HT40PLUS | CHANNEL_HT;
		else
			flags |= CHANNEL_HT40MINUS | CHANNEL_HT;
		break;
	default:
		WARN_ON(1);
	}

	ichan->channelFlags = flags;
}

/*
 * Get the internal channel reference.
 */
struct ath9k_channel *ath9k_cmn_get_channel(struct ieee80211_hw *hw,
					    struct ath_hw *ah,
					    struct cfg80211_chan_def *chandef)
{
	struct ieee80211_channel *curchan = chandef->chan;
	struct ath9k_channel *channel;

	channel = &ah->channels[curchan->hw_value];
	ath9k_cmn_update_ichannel(channel, chandef);

	return channel;
}
EXPORT_SYMBOL(ath9k_cmn_get_channel);

int ath9k_cmn_count_streams(unsigned int chainmask, int max)
{
	int streams = 0;

	do {
		if (++streams == max)
			break;
	} while ((chainmask = chainmask & (chainmask - 1)));

	return streams;
}
EXPORT_SYMBOL(ath9k_cmn_count_streams);

void ath9k_cmn_update_txpow(struct ath_hw *ah, u16 cur_txpow,
			    u16 new_txpow, u16 *txpower)
{
	struct ath_regulatory *reg = ath9k_hw_regulatory(ah);

	if (reg->power_limit != new_txpow)
		ath9k_hw_set_txpowerlimit(ah, new_txpow, false);

	/* read back in case value is clamped */
	*txpower = reg->max_power_level;
}
EXPORT_SYMBOL(ath9k_cmn_update_txpow);

void ath9k_cmn_init_crypto(struct ath_hw *ah)
{
	struct ath_common *common = ath9k_hw_common(ah);
	int i = 0;

	/* Get the hardware key cache size. */
	common->keymax = AR_KEYTABLE_SIZE;

	/*
	 * Check whether the separate key cache entries
	 * are required to handle both tx+rx MIC keys.
	 * With split mic keys the number of stations is limited
	 * to 27 otherwise 59.
	 */
	if (ah->misc_mode & AR_PCU_MIC_NEW_LOC_ENA)
		common->crypt_caps |= ATH_CRYPT_CAP_MIC_COMBINED;

	/*
	 * Reset the key cache since some parts do not
	 * reset the contents on initial power up.
	 */
	for (i = 0; i < common->keymax; i++)
		ath_hw_keyreset(common, (u16) i);
}
EXPORT_SYMBOL(ath9k_cmn_init_crypto);

static int __init ath9k_cmn_init(void)
{
	return 0;
}
module_init(ath9k_cmn_init);

static void __exit ath9k_cmn_exit(void)
{
	return;
}
module_exit(ath9k_cmn_exit);