1/*
2 * Copyright (c) 2009 Atheros Communications Inc.
3 * Copyright (c) 2010 Bruno Randolf <br1@einfach.org>
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include <linux/export.h>
19#include <asm/unaligned.h>
20#include <net/mac80211.h>
21
22#include "ath.h"
23#include "reg.h"
24
25#define REG_READ (common->ops->read)
26#define REG_WRITE(_ah, _reg, _val) (common->ops->write)(_ah, _val, _reg)
27#define ENABLE_REGWRITE_BUFFER(_ah) \
28 if (common->ops->enable_write_buffer) \
29 common->ops->enable_write_buffer((_ah));
30
31#define REGWRITE_BUFFER_FLUSH(_ah) \
32 if (common->ops->write_flush) \
33 common->ops->write_flush((_ah));
34
35
36#define IEEE80211_WEP_NKID 4 /* number of key ids */
37
38/************************/
39/* Key Cache Management */
40/************************/
41
42bool ath_hw_keyreset(struct ath_common *common, u16 entry)
43{
44 u32 keyType;
45 void *ah = common->ah;
46
47 if (entry >= common->keymax) {
48 ath_err(common, "keyreset: keycache entry %u out of range\n",
49 entry);
50 return false;
51 }
52
53 keyType = REG_READ(ah, AR_KEYTABLE_TYPE(entry));
54
55 ENABLE_REGWRITE_BUFFER(ah);
56
57 REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), 0);
58 REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), 0);
59 REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), 0);
60 REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), 0);
61 REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), 0);
62 REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), AR_KEYTABLE_TYPE_CLR);
63 REG_WRITE(ah, AR_KEYTABLE_MAC0(entry), 0);
64 REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), 0);
65
66 if (keyType == AR_KEYTABLE_TYPE_TKIP) {
67 u16 micentry = entry + 64;
68
69 REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), 0);
70 REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), 0);
71 REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), 0);
72 REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), 0);
73 if (common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED) {
74 REG_WRITE(ah, AR_KEYTABLE_KEY4(micentry), 0);
75 REG_WRITE(ah, AR_KEYTABLE_TYPE(micentry),
76 AR_KEYTABLE_TYPE_CLR);
77 }
78
79 }
80
81 REGWRITE_BUFFER_FLUSH(ah);
82
83 return true;
84}
85EXPORT_SYMBOL(ath_hw_keyreset);
86
87bool ath_hw_keysetmac(struct ath_common *common, u16 entry, const u8 *mac)
88{
89 u32 macHi, macLo;
90 u32 unicast_flag = AR_KEYTABLE_VALID;
91 void *ah = common->ah;
92
93 if (entry >= common->keymax) {
94 ath_err(common, "keysetmac: keycache entry %u out of range\n",
95 entry);
96 return false;
97 }
98
99 if (mac != NULL) {
100 /*
101 * AR_KEYTABLE_VALID indicates that the address is a unicast
102 * address, which must match the transmitter address for
103 * decrypting frames.
104 * Not setting this bit allows the hardware to use the key
105 * for multicast frame decryption.
106 */
107 if (is_multicast_ether_addr(addr: mac))
108 unicast_flag = 0;
109
110 macLo = get_unaligned_le32(p: mac);
111 macHi = get_unaligned_le16(p: mac + 4);
112 macLo >>= 1;
113 macLo |= (macHi & 1) << 31;
114 macHi >>= 1;
115 } else {
116 macLo = macHi = 0;
117 }
118 ENABLE_REGWRITE_BUFFER(ah);
119
120 REG_WRITE(ah, AR_KEYTABLE_MAC0(entry), macLo);
121 REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), macHi | unicast_flag);
122
123 REGWRITE_BUFFER_FLUSH(ah);
124
125 return true;
126}
127EXPORT_SYMBOL(ath_hw_keysetmac);
128
129static bool ath_hw_set_keycache_entry(struct ath_common *common, u16 entry,
130 const struct ath_keyval *k,
131 const u8 *mac)
132{
133 void *ah = common->ah;
134 u32 key0, key1, key2, key3, key4;
135 u32 keyType;
136
137 if (entry >= common->keymax) {
138 ath_err(common, "set-entry: keycache entry %u out of range\n",
139 entry);
140 return false;
141 }
142
143 switch (k->kv_type) {
144 case ATH_CIPHER_AES_OCB:
145 keyType = AR_KEYTABLE_TYPE_AES;
146 break;
147 case ATH_CIPHER_AES_CCM:
148 if (!(common->crypt_caps & ATH_CRYPT_CAP_CIPHER_AESCCM)) {
149 ath_dbg(common, ANY,
150 "AES-CCM not supported by this mac rev\n");
151 return false;
152 }
153 keyType = AR_KEYTABLE_TYPE_CCM;
154 break;
155 case ATH_CIPHER_TKIP:
156 keyType = AR_KEYTABLE_TYPE_TKIP;
157 if (entry + 64 >= common->keymax) {
158 ath_dbg(common, ANY,
159 "entry %u inappropriate for TKIP\n", entry);
160 return false;
161 }
162 break;
163 case ATH_CIPHER_WEP:
164 if (k->kv_len < WLAN_KEY_LEN_WEP40) {
165 ath_dbg(common, ANY, "WEP key length %u too small\n",
166 k->kv_len);
167 return false;
168 }
169 if (k->kv_len <= WLAN_KEY_LEN_WEP40)
170 keyType = AR_KEYTABLE_TYPE_40;
171 else if (k->kv_len <= WLAN_KEY_LEN_WEP104)
172 keyType = AR_KEYTABLE_TYPE_104;
173 else
174 keyType = AR_KEYTABLE_TYPE_128;
175 break;
176 case ATH_CIPHER_CLR:
177 keyType = AR_KEYTABLE_TYPE_CLR;
178 break;
179 default:
180 ath_err(common, "cipher %u not supported\n", k->kv_type);
181 return false;
182 }
183
184 key0 = get_unaligned_le32(p: k->kv_val + 0);
185 key1 = get_unaligned_le16(p: k->kv_val + 4);
186 key2 = get_unaligned_le32(p: k->kv_val + 6);
187 key3 = get_unaligned_le16(p: k->kv_val + 10);
188 key4 = get_unaligned_le32(p: k->kv_val + 12);
189 if (k->kv_len <= WLAN_KEY_LEN_WEP104)
190 key4 &= 0xff;
191
192 /*
193 * Note: Key cache registers access special memory area that requires
194 * two 32-bit writes to actually update the values in the internal
195 * memory. Consequently, the exact order and pairs used here must be
196 * maintained.
197 */
198
199 if (keyType == AR_KEYTABLE_TYPE_TKIP) {
200 u16 micentry = entry + 64;
201
202 /*
203 * Write inverted key[47:0] first to avoid Michael MIC errors
204 * on frames that could be sent or received at the same time.
205 * The correct key will be written in the end once everything
206 * else is ready.
207 */
208 REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), ~key0);
209 REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), ~key1);
210
211 /* Write key[95:48] */
212 REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), key2);
213 REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), key3);
214
215 /* Write key[127:96] and key type */
216 REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), key4);
217 REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), keyType);
218
219 /* Write MAC address for the entry */
220 (void) ath_hw_keysetmac(common, entry, mac);
221
222 if (common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED) {
223 /*
224 * TKIP uses two key cache entries:
225 * Michael MIC TX/RX keys in the same key cache entry
226 * (idx = main index + 64):
227 * key0 [31:0] = RX key [31:0]
228 * key1 [15:0] = TX key [31:16]
229 * key1 [31:16] = reserved
230 * key2 [31:0] = RX key [63:32]
231 * key3 [15:0] = TX key [15:0]
232 * key3 [31:16] = reserved
233 * key4 [31:0] = TX key [63:32]
234 */
235 u32 mic0, mic1, mic2, mic3, mic4;
236
237 mic0 = get_unaligned_le32(p: k->kv_mic + 0);
238 mic2 = get_unaligned_le32(p: k->kv_mic + 4);
239 mic1 = get_unaligned_le16(p: k->kv_txmic + 2) & 0xffff;
240 mic3 = get_unaligned_le16(p: k->kv_txmic + 0) & 0xffff;
241 mic4 = get_unaligned_le32(p: k->kv_txmic + 4);
242
243 ENABLE_REGWRITE_BUFFER(ah);
244
245 /* Write RX[31:0] and TX[31:16] */
246 REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), mic0);
247 REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), mic1);
248
249 /* Write RX[63:32] and TX[15:0] */
250 REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), mic2);
251 REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), mic3);
252
253 /* Write TX[63:32] and keyType(reserved) */
254 REG_WRITE(ah, AR_KEYTABLE_KEY4(micentry), mic4);
255 REG_WRITE(ah, AR_KEYTABLE_TYPE(micentry),
256 AR_KEYTABLE_TYPE_CLR);
257
258 REGWRITE_BUFFER_FLUSH(ah);
259
260 } else {
261 /*
262 * TKIP uses four key cache entries (two for group
263 * keys):
264 * Michael MIC TX/RX keys are in different key cache
265 * entries (idx = main index + 64 for TX and
266 * main index + 32 + 96 for RX):
267 * key0 [31:0] = TX/RX MIC key [31:0]
268 * key1 [31:0] = reserved
269 * key2 [31:0] = TX/RX MIC key [63:32]
270 * key3 [31:0] = reserved
271 * key4 [31:0] = reserved
272 *
273 * Upper layer code will call this function separately
274 * for TX and RX keys when these registers offsets are
275 * used.
276 */
277 u32 mic0, mic2;
278
279 mic0 = get_unaligned_le32(p: k->kv_mic + 0);
280 mic2 = get_unaligned_le32(p: k->kv_mic + 4);
281
282 ENABLE_REGWRITE_BUFFER(ah);
283
284 /* Write MIC key[31:0] */
285 REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), mic0);
286 REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), 0);
287
288 /* Write MIC key[63:32] */
289 REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), mic2);
290 REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), 0);
291
292 /* Write TX[63:32] and keyType(reserved) */
293 REG_WRITE(ah, AR_KEYTABLE_KEY4(micentry), 0);
294 REG_WRITE(ah, AR_KEYTABLE_TYPE(micentry),
295 AR_KEYTABLE_TYPE_CLR);
296
297 REGWRITE_BUFFER_FLUSH(ah);
298 }
299
300 ENABLE_REGWRITE_BUFFER(ah);
301
302 /* MAC address registers are reserved for the MIC entry */
303 REG_WRITE(ah, AR_KEYTABLE_MAC0(micentry), 0);
304 REG_WRITE(ah, AR_KEYTABLE_MAC1(micentry), 0);
305
306 /*
307 * Write the correct (un-inverted) key[47:0] last to enable
308 * TKIP now that all other registers are set with correct
309 * values.
310 */
311 REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), key0);
312 REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), key1);
313
314 REGWRITE_BUFFER_FLUSH(ah);
315 } else {
316 ENABLE_REGWRITE_BUFFER(ah);
317
318 /* Write key[47:0] */
319 REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), key0);
320 REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), key1);
321
322 /* Write key[95:48] */
323 REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), key2);
324 REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), key3);
325
326 /* Write key[127:96] and key type */
327 REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), key4);
328 REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), keyType);
329
330 REGWRITE_BUFFER_FLUSH(ah);
331
332 /* Write MAC address for the entry */
333 (void) ath_hw_keysetmac(common, entry, mac);
334 }
335
336 return true;
337}
338
339static int ath_setkey_tkip(struct ath_common *common, u16 keyix, const u8 *key,
340 struct ath_keyval *hk, const u8 *addr,
341 bool authenticator)
342{
343 const u8 *key_rxmic;
344 const u8 *key_txmic;
345
346 key_txmic = key + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
347 key_rxmic = key + NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
348
349 if (addr == NULL) {
350 /*
351 * Group key installation - only two key cache entries are used
352 * regardless of splitmic capability since group key is only
353 * used either for TX or RX.
354 */
355 if (authenticator) {
356 memcpy(hk->kv_mic, key_txmic, sizeof(hk->kv_mic));
357 memcpy(hk->kv_txmic, key_txmic, sizeof(hk->kv_mic));
358 } else {
359 memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
360 memcpy(hk->kv_txmic, key_rxmic, sizeof(hk->kv_mic));
361 }
362 return ath_hw_set_keycache_entry(common, entry: keyix, k: hk, mac: addr);
363 }
364 if (common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED) {
365 /* TX and RX keys share the same key cache entry. */
366 memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
367 memcpy(hk->kv_txmic, key_txmic, sizeof(hk->kv_txmic));
368 return ath_hw_set_keycache_entry(common, entry: keyix, k: hk, mac: addr);
369 }
370
371 /* Separate key cache entries for TX and RX */
372
373 /* TX key goes at first index, RX key at +32. */
374 memcpy(hk->kv_mic, key_txmic, sizeof(hk->kv_mic));
375 if (!ath_hw_set_keycache_entry(common, entry: keyix, k: hk, NULL)) {
376 /* TX MIC entry failed. No need to proceed further */
377 ath_err(common, "Setting TX MIC Key Failed\n");
378 return 0;
379 }
380
381 memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
382 /* XXX delete tx key on failure? */
383 return ath_hw_set_keycache_entry(common, entry: keyix + 32, k: hk, mac: addr);
384}
385
386static int ath_reserve_key_cache_slot_tkip(struct ath_common *common)
387{
388 int i;
389
390 for (i = IEEE80211_WEP_NKID; i < common->keymax / 2; i++) {
391 if (test_bit(i, common->keymap) ||
392 test_bit(i + 64, common->keymap))
393 continue; /* At least one part of TKIP key allocated */
394 if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED) &&
395 (test_bit(i + 32, common->keymap) ||
396 test_bit(i + 64 + 32, common->keymap)))
397 continue; /* At least one part of TKIP key allocated */
398
399 /* Found a free slot for a TKIP key */
400 return i;
401 }
402 return -1;
403}
404
405static int ath_reserve_key_cache_slot(struct ath_common *common,
406 u32 cipher)
407{
408 int i;
409
410 if (cipher == WLAN_CIPHER_SUITE_TKIP)
411 return ath_reserve_key_cache_slot_tkip(common);
412
413 /* First, try to find slots that would not be available for TKIP. */
414 if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED)) {
415 for (i = IEEE80211_WEP_NKID; i < common->keymax / 4; i++) {
416 if (!test_bit(i, common->keymap) &&
417 (test_bit(i + 32, common->keymap) ||
418 test_bit(i + 64, common->keymap) ||
419 test_bit(i + 64 + 32, common->keymap)))
420 return i;
421 if (!test_bit(i + 32, common->keymap) &&
422 (test_bit(i, common->keymap) ||
423 test_bit(i + 64, common->keymap) ||
424 test_bit(i + 64 + 32, common->keymap)))
425 return i + 32;
426 if (!test_bit(i + 64, common->keymap) &&
427 (test_bit(i , common->keymap) ||
428 test_bit(i + 32, common->keymap) ||
429 test_bit(i + 64 + 32, common->keymap)))
430 return i + 64;
431 if (!test_bit(i + 64 + 32, common->keymap) &&
432 (test_bit(i, common->keymap) ||
433 test_bit(i + 32, common->keymap) ||
434 test_bit(i + 64, common->keymap)))
435 return i + 64 + 32;
436 }
437 } else {
438 for (i = IEEE80211_WEP_NKID; i < common->keymax / 2; i++) {
439 if (!test_bit(i, common->keymap) &&
440 test_bit(i + 64, common->keymap))
441 return i;
442 if (test_bit(i, common->keymap) &&
443 !test_bit(i + 64, common->keymap))
444 return i + 64;
445 }
446 }
447
448 /* No partially used TKIP slots, pick any available slot */
449 for (i = IEEE80211_WEP_NKID; i < common->keymax; i++) {
450 /* Do not allow slots that could be needed for TKIP group keys
451 * to be used. This limitation could be removed if we know that
452 * TKIP will not be used. */
453 if (i >= 64 && i < 64 + IEEE80211_WEP_NKID)
454 continue;
455 if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED)) {
456 if (i >= 32 && i < 32 + IEEE80211_WEP_NKID)
457 continue;
458 if (i >= 64 + 32 && i < 64 + 32 + IEEE80211_WEP_NKID)
459 continue;
460 }
461
462 if (!test_bit(i, common->keymap))
463 return i; /* Found a free slot for a key */
464 }
465
466 /* No free slot found */
467 return -1;
468}
469
470/*
471 * Configure encryption in the HW.
472 */
473int ath_key_config(struct ath_common *common,
474 struct ieee80211_vif *vif,
475 struct ieee80211_sta *sta,
476 struct ieee80211_key_conf *key)
477{
478 struct ath_keyval hk;
479 const u8 *mac = NULL;
480 u8 gmac[ETH_ALEN];
481 int ret = 0;
482 int idx;
483
484 memset(&hk, 0, sizeof(hk));
485
486 switch (key->cipher) {
487 case 0:
488 hk.kv_type = ATH_CIPHER_CLR;
489 break;
490 case WLAN_CIPHER_SUITE_WEP40:
491 case WLAN_CIPHER_SUITE_WEP104:
492 hk.kv_type = ATH_CIPHER_WEP;
493 break;
494 case WLAN_CIPHER_SUITE_TKIP:
495 hk.kv_type = ATH_CIPHER_TKIP;
496 break;
497 case WLAN_CIPHER_SUITE_CCMP:
498 hk.kv_type = ATH_CIPHER_AES_CCM;
499 break;
500 default:
501 return -EOPNOTSUPP;
502 }
503
504 hk.kv_len = key->keylen;
505 if (key->keylen)
506 memcpy(&hk.kv_values, key->key, key->keylen);
507
508 if (!(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
509 switch (vif->type) {
510 case NL80211_IFTYPE_AP:
511 memcpy(gmac, vif->addr, ETH_ALEN);
512 gmac[0] |= 0x01;
513 mac = gmac;
514 idx = ath_reserve_key_cache_slot(common, cipher: key->cipher);
515 break;
516 case NL80211_IFTYPE_ADHOC:
517 if (!sta) {
518 idx = key->keyidx;
519 break;
520 }
521 memcpy(gmac, sta->addr, ETH_ALEN);
522 gmac[0] |= 0x01;
523 mac = gmac;
524 idx = ath_reserve_key_cache_slot(common, cipher: key->cipher);
525 break;
526 default:
527 idx = key->keyidx;
528 break;
529 }
530 } else if (key->keyidx) {
531 if (WARN_ON(!sta))
532 return -EOPNOTSUPP;
533 mac = sta->addr;
534
535 if (vif->type != NL80211_IFTYPE_AP) {
536 /* Only keyidx 0 should be used with unicast key, but
537 * allow this for client mode for now. */
538 idx = key->keyidx;
539 } else
540 return -EIO;
541 } else {
542 if (WARN_ON(!sta))
543 return -EOPNOTSUPP;
544 mac = sta->addr;
545
546 idx = ath_reserve_key_cache_slot(common, cipher: key->cipher);
547 }
548
549 if (idx < 0)
550 return -ENOSPC; /* no free key cache entries */
551
552 if (key->cipher == WLAN_CIPHER_SUITE_TKIP)
553 ret = ath_setkey_tkip(common, keyix: idx, key: key->key, hk: &hk, addr: mac,
554 authenticator: vif->type == NL80211_IFTYPE_AP);
555 else
556 ret = ath_hw_set_keycache_entry(common, entry: idx, k: &hk, mac);
557
558 if (!ret)
559 return -EIO;
560
561 set_bit(nr: idx, addr: common->keymap);
562 if (key->cipher == WLAN_CIPHER_SUITE_CCMP)
563 set_bit(nr: idx, addr: common->ccmp_keymap);
564
565 if (key->cipher == WLAN_CIPHER_SUITE_TKIP) {
566 set_bit(nr: idx + 64, addr: common->keymap);
567 set_bit(nr: idx, addr: common->tkip_keymap);
568 set_bit(nr: idx + 64, addr: common->tkip_keymap);
569 if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED)) {
570 set_bit(nr: idx + 32, addr: common->keymap);
571 set_bit(nr: idx + 64 + 32, addr: common->keymap);
572 set_bit(nr: idx + 32, addr: common->tkip_keymap);
573 set_bit(nr: idx + 64 + 32, addr: common->tkip_keymap);
574 }
575 }
576
577 return idx;
578}
579EXPORT_SYMBOL(ath_key_config);
580
581/*
582 * Delete Key.
583 */
584void ath_key_delete(struct ath_common *common, u8 hw_key_idx)
585{
586 /* Leave CCMP and TKIP (main key) configured to avoid disabling
587 * encryption for potentially pending frames already in a TXQ with the
588 * keyix pointing to this key entry. Instead, only clear the MAC address
589 * to prevent RX processing from using this key cache entry.
590 */
591 if (test_bit(hw_key_idx, common->ccmp_keymap) ||
592 test_bit(hw_key_idx, common->tkip_keymap))
593 ath_hw_keysetmac(common, hw_key_idx, NULL);
594 else
595 ath_hw_keyreset(common, hw_key_idx);
596 if (hw_key_idx < IEEE80211_WEP_NKID)
597 return;
598
599 clear_bit(nr: hw_key_idx, addr: common->keymap);
600 clear_bit(nr: hw_key_idx, addr: common->ccmp_keymap);
601 if (!test_bit(hw_key_idx, common->tkip_keymap))
602 return;
603
604 clear_bit(nr: hw_key_idx + 64, addr: common->keymap);
605
606 clear_bit(nr: hw_key_idx, addr: common->tkip_keymap);
607 clear_bit(nr: hw_key_idx + 64, addr: common->tkip_keymap);
608
609 if (!(common->crypt_caps & ATH_CRYPT_CAP_MIC_COMBINED)) {
610 ath_hw_keyreset(common, hw_key_idx + 32);
611 clear_bit(nr: hw_key_idx + 32, addr: common->keymap);
612 clear_bit(nr: hw_key_idx + 64 + 32, addr: common->keymap);
613
614 clear_bit(nr: hw_key_idx + 32, addr: common->tkip_keymap);
615 clear_bit(nr: hw_key_idx + 64 + 32, addr: common->tkip_keymap);
616 }
617}
618EXPORT_SYMBOL(ath_key_delete);
619

source code of linux/drivers/net/wireless/ath/key.c