1 /*
2  * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
3  * Copyright (c) 2002-2008 Atheros Communications, Inc.
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  * $Id: ar5212_keycache.c,v 1.1.1.1 2008/12/11 04:46:40 alc Exp $
18  */
19 #include "opt_ah.h"
20 
21 #include "ah.h"
22 #include "ah_internal.h"
23 
24 #include "ar5212/ar5212.h"
25 #include "ar5212/ar5212reg.h"
26 #include "ar5212/ar5212desc.h"
27 
28 /*
29  * Note: The key cache hardware requires that each double-word
30  * pair be written in even/odd order (since the destination is
31  * a 64-bit register).  Don't reorder the writes in this code
32  * w/o considering this!
33  */
34 #define	KEY_XOR			0xaa
35 
36 #define	IS_MIC_ENABLED(ah) \
37 	(AH5212(ah)->ah_staId1Defaults & AR_STA_ID1_CRPT_MIC_ENABLE)
38 
39 /*
40  * Return the size of the hardware key cache.
41  */
42 uint32_t
ar5212GetKeyCacheSize(struct ath_hal * ah)43 ar5212GetKeyCacheSize(struct ath_hal *ah)
44 {
45 	return AH_PRIVATE(ah)->ah_caps.halKeyCacheSize;
46 }
47 
48 /*
49  * Return true if the specific key cache entry is valid.
50  */
51 HAL_BOOL
ar5212IsKeyCacheEntryValid(struct ath_hal * ah,uint16_t entry)52 ar5212IsKeyCacheEntryValid(struct ath_hal *ah, uint16_t entry)
53 {
54 	if (entry < AH_PRIVATE(ah)->ah_caps.halKeyCacheSize) {
55 		uint32_t val = OS_REG_READ(ah, AR_KEYTABLE_MAC1(entry));
56 		if (val & AR_KEYTABLE_VALID)
57 			return AH_TRUE;
58 	}
59 	return AH_FALSE;
60 }
61 
62 /*
63  * Clear the specified key cache entry and any associated MIC entry.
64  */
65 HAL_BOOL
ar5212ResetKeyCacheEntry(struct ath_hal * ah,uint16_t entry)66 ar5212ResetKeyCacheEntry(struct ath_hal *ah, uint16_t entry)
67 {
68 	uint32_t keyType;
69 
70 	if (entry >= AH_PRIVATE(ah)->ah_caps.halKeyCacheSize) {
71 		HALDEBUG(ah, HAL_DEBUG_ANY, "%s: entry %u out of range\n",
72 		    __func__, entry);
73 		return AH_FALSE;
74 	}
75 	keyType = OS_REG_READ(ah, AR_KEYTABLE_TYPE(entry));
76 
77 	/* XXX why not clear key type/valid bit first? */
78 	OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), 0);
79 	OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), 0);
80 	OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), 0);
81 	OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), 0);
82 	OS_REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), 0);
83 	OS_REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), AR_KEYTABLE_TYPE_CLR);
84 	OS_REG_WRITE(ah, AR_KEYTABLE_MAC0(entry), 0);
85 	OS_REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), 0);
86 	if (keyType == AR_KEYTABLE_TYPE_TKIP && IS_MIC_ENABLED(ah)) {
87 		uint16_t micentry = entry+64;	/* MIC goes at slot+64 */
88 
89 		HALASSERT(micentry < AH_PRIVATE(ah)->ah_caps.halKeyCacheSize);
90 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), 0);
91 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), 0);
92 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), 0);
93 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), 0);
94 		/* NB: key type and MAC are known to be ok */
95 	}
96 	return AH_TRUE;
97 }
98 
99 /*
100  * Sets the mac part of the specified key cache entry (and any
101  * associated MIC entry) and mark them valid.
102  */
103 HAL_BOOL
ar5212SetKeyCacheEntryMac(struct ath_hal * ah,uint16_t entry,const uint8_t * mac)104 ar5212SetKeyCacheEntryMac(struct ath_hal *ah, uint16_t entry, const uint8_t *mac)
105 {
106 	uint32_t macHi, macLo;
107 
108 	if (entry >= AH_PRIVATE(ah)->ah_caps.halKeyCacheSize) {
109 		HALDEBUG(ah, HAL_DEBUG_ANY, "%s: entry %u out of range\n",
110 		    __func__, entry);
111 		return AH_FALSE;
112 	}
113 	/*
114 	 * Set MAC address -- shifted right by 1.  MacLo is
115 	 * the 4 MSBs, and MacHi is the 2 LSBs.
116 	 */
117 	if (mac != AH_NULL) {
118 		macHi = (mac[5] << 8) | mac[4];
119 		macLo = (mac[3] << 24)| (mac[2] << 16)
120 		      | (mac[1] << 8) | mac[0];
121 		macLo >>= 1;
122 		macLo |= (macHi & 1) << 31;	/* carry */
123 		macHi >>= 1;
124 	} else {
125 		macLo = macHi = 0;
126 	}
127 	OS_REG_WRITE(ah, AR_KEYTABLE_MAC0(entry), macLo);
128 	OS_REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), macHi | AR_KEYTABLE_VALID);
129 	return AH_TRUE;
130 }
131 
132 /*
133  * Sets the contents of the specified key cache entry
134  * and any associated MIC entry.
135  */
136 HAL_BOOL
ar5212SetKeyCacheEntry(struct ath_hal * ah,uint16_t entry,const HAL_KEYVAL * k,const uint8_t * mac,int xorKey)137 ar5212SetKeyCacheEntry(struct ath_hal *ah, uint16_t entry,
138                        const HAL_KEYVAL *k, const uint8_t *mac,
139                        int xorKey)
140 {
141 	struct ath_hal_5212 *ahp = AH5212(ah);
142 	const HAL_CAPABILITIES *pCap = &AH_PRIVATE(ah)->ah_caps;
143 	uint32_t key0, key1, key2, key3, key4;
144 	uint32_t keyType;
145 	uint32_t xorMask = xorKey ?
146 		(KEY_XOR << 24 | KEY_XOR << 16 | KEY_XOR << 8 | KEY_XOR) : 0;
147 
148 	if (entry >= pCap->halKeyCacheSize) {
149 		HALDEBUG(ah, HAL_DEBUG_ANY, "%s: entry %u out of range\n",
150 		    __func__, entry);
151 		return AH_FALSE;
152 	}
153 	switch (k->kv_type) {
154 	case HAL_CIPHER_AES_OCB:
155 		keyType = AR_KEYTABLE_TYPE_AES;
156 		break;
157 	case HAL_CIPHER_AES_CCM:
158 		if (!pCap->halCipherAesCcmSupport) {
159 			HALDEBUG(ah, HAL_DEBUG_ANY,
160 			    "%s: AES-CCM not supported by mac rev 0x%x\n",
161 			    __func__, AH_PRIVATE(ah)->ah_macRev);
162 			return AH_FALSE;
163 		}
164 		keyType = AR_KEYTABLE_TYPE_CCM;
165 		break;
166 	case HAL_CIPHER_TKIP:
167 		keyType = AR_KEYTABLE_TYPE_TKIP;
168 		if (IS_MIC_ENABLED(ah) && entry+64 >= pCap->halKeyCacheSize) {
169 			HALDEBUG(ah, HAL_DEBUG_ANY,
170 			    "%s: entry %u inappropriate for TKIP\n",
171 			    __func__, entry);
172 			return AH_FALSE;
173 		}
174 		break;
175 	case HAL_CIPHER_WEP:
176 		if (k->kv_len < 40 / NBBY) {
177 			HALDEBUG(ah, HAL_DEBUG_ANY,
178 			    "%s: WEP key length %u too small\n",
179 			    __func__, k->kv_len);
180 			return AH_FALSE;
181 		}
182 		if (k->kv_len <= 40 / NBBY)
183 			keyType = AR_KEYTABLE_TYPE_40;
184 		else if (k->kv_len <= 104 / NBBY)
185 			keyType = AR_KEYTABLE_TYPE_104;
186 		else
187 			keyType = AR_KEYTABLE_TYPE_128;
188 		break;
189 	case HAL_CIPHER_CLR:
190 		keyType = AR_KEYTABLE_TYPE_CLR;
191 		break;
192 	default:
193 		HALDEBUG(ah, HAL_DEBUG_ANY, "%s: cipher %u not supported\n",
194 		    __func__, k->kv_type);
195 		return AH_FALSE;
196 	}
197 
198 	key0 = LE_READ_4(k->kv_val+0) ^ xorMask;
199 	key1 = (LE_READ_2(k->kv_val+4) ^ xorMask) & 0xffff;
200 	key2 = LE_READ_4(k->kv_val+6) ^ xorMask;
201 	key3 = (LE_READ_2(k->kv_val+10) ^ xorMask) & 0xffff;
202 	key4 = LE_READ_4(k->kv_val+12) ^ xorMask;
203 	if (k->kv_len <= 104 / NBBY)
204 		key4 &= 0xff;
205 
206 	/*
207 	 * Note: key cache hardware requires that each double-word
208 	 * pair be written in even/odd order (since the destination is
209 	 * a 64-bit register).  Don't reorder these writes w/o
210 	 * considering this!
211 	 */
212 	if (keyType == AR_KEYTABLE_TYPE_TKIP && IS_MIC_ENABLED(ah)) {
213 		uint16_t micentry = entry+64;	/* MIC goes at slot+64 */
214 		uint32_t mic0, mic1, mic2, mic3, mic4;
215 
216 		/*
217 		 * Invalidate the encrypt/decrypt key until the MIC
218 		 * key is installed so pending rx frames will fail
219 		 * with decrypt errors rather than a MIC error.
220 		 */
221 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), ~key0);
222 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), ~key1);
223 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), key2);
224 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), key3);
225 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), key4);
226 		OS_REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), keyType);
227 		(void) ar5212SetKeyCacheEntryMac(ah, entry, mac);
228 
229 
230 		/*
231 		 * Write MIC entry according to new or old key layout.
232 		 * The MISC_MODE register is assumed already set so
233 		 * these writes will be handled properly (happens on
234 		 * attach and at every reset).
235 		 */
236 		/* RX mic */
237 		mic0 = LE_READ_4(k->kv_mic+0);
238 		mic2 = LE_READ_4(k->kv_mic+4);
239 		if (ahp->ah_miscMode & AR_MISC_MODE_MIC_NEW_LOC_ENABLE) {
240 			/*
241 			 * Both RX and TX mic values can be combined into
242 			 * one cache slot entry:
243 			 *  8*N + 800         31:0    RX Michael key 0
244 			 *  8*N + 804         15:0    TX Michael key 0 [31:16]
245 			 *  8*N + 808         31:0    RX Michael key 1
246 			 *  8*N + 80C         15:0    TX Michael key 0 [15:0]
247 			 *  8*N + 810         31:0    TX Michael key 1
248 			 *  8*N + 814         15:0    reserved
249 			 *  8*N + 818         31:0    reserved
250 			 *  8*N + 81C         14:0    reserved
251 			 *                    15      key valid == 0
252 			 */
253 			/* TX mic */
254 			mic1 = LE_READ_2(k->kv_txmic+2) & 0xffff;
255 			mic3 = LE_READ_2(k->kv_txmic+0) & 0xffff;
256 			mic4 = LE_READ_4(k->kv_txmic+4);
257 		} else {
258 			mic1 = mic3 = mic4 = 0;
259 		}
260 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), mic0);
261 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), mic1);
262 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), mic2);
263 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), mic3);
264 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY4(micentry), mic4);
265 		OS_REG_WRITE(ah, AR_KEYTABLE_TYPE(micentry),
266 			AR_KEYTABLE_TYPE_CLR);
267 		/* NB: MIC key is not marked valid and has no MAC address */
268 		OS_REG_WRITE(ah, AR_KEYTABLE_MAC0(micentry), 0);
269 		OS_REG_WRITE(ah, AR_KEYTABLE_MAC1(micentry), 0);
270 
271 		/* correct intentionally corrupted key */
272 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), key0);
273 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), key1);
274 	} else {
275 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), key0);
276 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), key1);
277 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), key2);
278 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), key3);
279 		OS_REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), key4);
280 		OS_REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), keyType);
281 
282 		(void) ar5212SetKeyCacheEntryMac(ah, entry, mac);
283 	}
284 	return AH_TRUE;
285 }
286