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      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
     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
     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
     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
    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
    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