drivers/net/wireless/ath/ath9k/common.c - arm/linux-arm64-legacy - Git at Google

 /*
  * Copyright (c) 2009 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");

 /* Common RX processing */

 /* Assumes you've already done the endian to CPU conversion */
 static bool ath9k_rx_accept(struct ath_common *common,
 			    struct sk_buff *skb,
 			    struct ieee80211_rx_status *rxs,
 			    struct ath_rx_status *rx_stats,
 			    bool *decrypt_error)
 {
 	struct ath_hw *ah = common->ah;
 	struct ieee80211_hdr *hdr;
 	__le16 fc;

 	hdr = (struct ieee80211_hdr *) skb->data;
 	fc = hdr->frame_control;

 	if (!rx_stats->rs_datalen)
 		return false;
         /*
          * rs_status follows rs_datalen so if rs_datalen is too large
          * we can take a hint that hardware corrupted it, so ignore
          * those frames.
          */
 	if (rx_stats->rs_datalen > common->rx_bufsize)
 		return false;

 	/*
 	 * rs_more indicates chained descriptors which can be used
 	 * to link buffers together for a sort of scatter-gather
 	 * operation.
 	 * reject the frame, we don't support scatter-gather yet and
 	 * the frame is probably corrupt anyway
 	 */
 	if (rx_stats->rs_more)
 		return false;

 	/*
 	 * 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) {
 		if (rx_stats->rs_status & ATH9K_RXERR_CRC)
 			rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
 		if (rx_stats->rs_status & ATH9K_RXERR_PHY)
 			return false;

 		if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
 			*decrypt_error = true;
 		} else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
 			if (ieee80211_is_ctl(fc))
 				/*
 				 * Sometimes, we get invalid
 				 * MIC failures on valid control frames.
 				 * Remove these mic errors.
 				 */
 				rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
 			else
 				rxs->flag |= RX_FLAG_MMIC_ERROR;
 		}
 		/*
 		 * Reject error frames with the exception of
 		 * decryption and MIC failures. For monitor mode,
 		 * we also ignore the CRC error.
 		 */
 		if (ah->opmode == NL80211_IFTYPE_MONITOR) {
 			if (rx_stats->rs_status &
 			    ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
 			      ATH9K_RXERR_CRC))
 				return false;
 		} else {
 			if (rx_stats->rs_status &
 			    ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
 				return false;
 			}
 		}
 	}
 	return true;
 }

 static int ath9k_process_rate(struct ath_common *common,
 			      struct ieee80211_hw *hw,
 			      struct ath_rx_status *rx_stats,
 			      struct ieee80211_rx_status *rxs,
 			      struct sk_buff *skb)
 {
 	struct ieee80211_supported_band *sband;
 	enum ieee80211_band band;
 	unsigned int i = 0;

 	band = hw->conf.channel->band;
 	sband = hw->wiphy->bands[band];

 	if (rx_stats->rs_rate & 0x80) {
 		/* HT rate */
 		rxs->flag |= RX_FLAG_HT;
 		if (rx_stats->rs_flags & ATH9K_RX_2040)
 			rxs->flag |= RX_FLAG_40MHZ;
 		if (rx_stats->rs_flags & ATH9K_RX_GI)
 			rxs->flag |= RX_FLAG_SHORT_GI;
 		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;
 		}
 	}

 	/*
 	 * No valid hardware bitrate found -- we should not get here
 	 * because hardware has already validated this frame as OK.
 	 */
 	ath_print(common, ATH_DBG_XMIT, "unsupported hw bitrate detected "
 		  "0x%02x using 1 Mbit\n", rx_stats->rs_rate);
 	if ((common->debug_mask & ATH_DBG_XMIT))
 		print_hex_dump_bytes("", DUMP_PREFIX_NONE, skb->data, skb->len);

 	return -EINVAL;
 }

 static void ath9k_process_rssi(struct ath_common *common,
 			       struct ieee80211_hw *hw,
 			       struct sk_buff *skb,
 			       struct ath_rx_status *rx_stats)
 {
 	struct ath_hw *ah = common->ah;
 	struct ieee80211_sta *sta;
 	struct ieee80211_hdr *hdr;
 	struct ath_node *an;
 	int last_rssi = ATH_RSSI_DUMMY_MARKER;
 	__le16 fc;

 	hdr = (struct ieee80211_hdr *)skb->data;
 	fc = hdr->frame_control;

 	rcu_read_lock();
 	/*
 	 * XXX: use ieee80211_find_sta! This requires quite a bit of work
 	 * under the current ath9k virtual wiphy implementation as we have
 	 * no way of tying a vif to wiphy. Typically vifs are attached to
 	 * at least one sdata of a wiphy on mac80211 but with ath9k virtual
 	 * wiphy you'd have to iterate over every wiphy and each sdata.
 	 */
 	sta = ieee80211_find_sta_by_hw(hw, hdr->addr2);
 	if (sta) {
 		an = (struct ath_node *) sta->drv_priv;
 		if (rx_stats->rs_rssi != ATH9K_RSSI_BAD &&
 		   !rx_stats->rs_moreaggr)
 			ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi);
 		last_rssi = an->last_rssi;
 	}
 	rcu_read_unlock();

 	if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
 		rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
 					      ATH_RSSI_EP_MULTIPLIER);
 	if (rx_stats->rs_rssi < 0)
 		rx_stats->rs_rssi = 0;

 	/* Update Beacon RSSI, this is used by ANI. */
 	if (ieee80211_is_beacon(fc))
 		ah->stats.avgbrssi = rx_stats->rs_rssi;
 }

 /*
  * For Decrypt or Demic errors, we only mark packet status here and always push
  * up the frame up to let mac80211 handle the actual error case, be it no
  * decryption key or real decryption error. This let us keep statistics there.
  */
 int ath9k_cmn_rx_skb_preprocess(struct ath_common *common,
 				struct ieee80211_hw *hw,
 				struct sk_buff *skb,
 				struct ath_rx_status *rx_stats,
 				struct ieee80211_rx_status *rx_status,
 				bool *decrypt_error)
 {
 	struct ath_hw *ah = common->ah;

 	memset(rx_status, 0, sizeof(struct ieee80211_rx_status));

 	/*
 	 * everything but the rate is checked here, the rate check is done
 	 * separately to avoid doing two lookups for a rate for each frame.
 	 */
 	if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error))
 		return -EINVAL;

 	ath9k_process_rssi(common, hw, skb, rx_stats);

 	if (ath9k_process_rate(common, hw, rx_stats, rx_status, skb))
 		return -EINVAL;

 	rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
 	rx_status->band = hw->conf.channel->band;
 	rx_status->freq = hw->conf.channel->center_freq;
 	rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
 	rx_status->antenna = rx_stats->rs_antenna;
 	rx_status->flag |= RX_FLAG_TSFT;

 	return 0;
 }
 EXPORT_SYMBOL(ath9k_cmn_rx_skb_preprocess);

 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 = ath9k_cmn_padpos(hdr->frame_control);

 	/* 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_padpos(__le16 frame_control)
 {
 	int padpos = 24;
 	if (ieee80211_has_a4(frame_control)) {
 		padpos += ETH_ALEN;
 	}
 	if (ieee80211_is_data_qos(frame_control)) {
 		padpos += IEEE80211_QOS_CTL_LEN;
 	}

 	return padpos;
 }
 EXPORT_SYMBOL(ath9k_cmn_padpos);

 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) {
 		if (tx_info->control.hw_key->alg == ALG_WEP)
 			return ATH9K_KEY_TYPE_WEP;
 		else if (tx_info->control.hw_key->alg == ALG_TKIP)
 			return ATH9K_KEY_TYPE_TKIP;
 		else if (tx_info->control.hw_key->alg == ALG_CCMP)
 			return ATH9K_KEY_TYPE_AES;
 	}

 	return ATH9K_KEY_TYPE_CLEAR;
 }
 EXPORT_SYMBOL(ath9k_cmn_get_hw_crypto_keytype);

 static u32 ath9k_get_extchanmode(struct ieee80211_channel *chan,
 				 enum nl80211_channel_type channel_type)
 {
 	u32 chanmode = 0;

 	switch (chan->band) {
 	case IEEE80211_BAND_2GHZ:
 		switch (channel_type) {
 		case NL80211_CHAN_NO_HT:
 		case NL80211_CHAN_HT20:
 			chanmode = CHANNEL_G_HT20;
 			break;
 		case NL80211_CHAN_HT40PLUS:
 			chanmode = CHANNEL_G_HT40PLUS;
 			break;
 		case NL80211_CHAN_HT40MINUS:
 			chanmode = CHANNEL_G_HT40MINUS;
 			break;
 		}
 		break;
 	case IEEE80211_BAND_5GHZ:
 		switch (channel_type) {
 		case NL80211_CHAN_NO_HT:
 		case NL80211_CHAN_HT20:
 			chanmode = CHANNEL_A_HT20;
 			break;
 		case NL80211_CHAN_HT40PLUS:
 			chanmode = CHANNEL_A_HT40PLUS;
 			break;
 		case NL80211_CHAN_HT40MINUS:
 			chanmode = CHANNEL_A_HT40MINUS;
 			break;
 		}
 		break;
 	default:
 		break;
 	}

 	return chanmode;
 }

 /*
  * Update internal channel flags.
  */
 void ath9k_cmn_update_ichannel(struct ieee80211_hw *hw,
 			       struct ath9k_channel *ichan)
 {
 	struct ieee80211_channel *chan = hw->conf.channel;
 	struct ieee80211_conf *conf = &hw->conf;

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

 	if (chan->band == IEEE80211_BAND_2GHZ) {
 		ichan->chanmode = CHANNEL_G;
 		ichan->channelFlags = CHANNEL_2GHZ | CHANNEL_OFDM | CHANNEL_G;
 	} else {
 		ichan->chanmode = CHANNEL_A;
 		ichan->channelFlags = CHANNEL_5GHZ | CHANNEL_OFDM;
 	}

 	if (conf_is_ht(conf))
 		ichan->chanmode = ath9k_get_extchanmode(chan,
 							conf->channel_type);
 }
 EXPORT_SYMBOL(ath9k_cmn_update_ichannel);

 /*
  * Get the internal channel reference.
  */
 struct ath9k_channel *ath9k_cmn_get_curchannel(struct ieee80211_hw *hw,
 					       struct ath_hw *ah)
 {
 	struct ieee80211_channel *curchan = hw->conf.channel;
 	struct ath9k_channel *channel;
 	u8 chan_idx;

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

 	return channel;
 }
 EXPORT_SYMBOL(ath9k_cmn_get_curchannel);

 static int ath_setkey_tkip(struct ath_common *common, u16 keyix, const u8 *key,
 			   struct ath9k_keyval *hk, const u8 *addr,
 			   bool authenticator)
 {
 	struct ath_hw *ah = common->ah;
 	const u8 *key_rxmic;
 	const u8 *key_txmic;

 	key_txmic = key + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
 	key_rxmic = key + NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;

 	if (addr == NULL) {
 		/*
 		 * Group key installation - only two key cache entries are used
 		 * regardless of splitmic capability since group key is only
 		 * used either for TX or RX.
 		 */
 		if (authenticator) {
 			memcpy(hk->kv_mic, key_txmic, sizeof(hk->kv_mic));
 			memcpy(hk->kv_txmic, key_txmic, sizeof(hk->kv_mic));
 		} else {
 			memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
 			memcpy(hk->kv_txmic, key_rxmic, sizeof(hk->kv_mic));
 		}
 		return ath9k_hw_set_keycache_entry(ah, keyix, hk, addr);
 	}
 	if (!common->splitmic) {
 		/* TX and RX keys share the same key cache entry. */
 		memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
 		memcpy(hk->kv_txmic, key_txmic, sizeof(hk->kv_txmic));
 		return ath9k_hw_set_keycache_entry(ah, keyix, hk, addr);
 	}

 	/* Separate key cache entries for TX and RX */

 	/* TX key goes at first index, RX key at +32. */
 	memcpy(hk->kv_mic, key_txmic, sizeof(hk->kv_mic));
 	if (!ath9k_hw_set_keycache_entry(ah, keyix, hk, NULL)) {
 		/* TX MIC entry failed. No need to proceed further */
 		ath_print(common, ATH_DBG_FATAL,
 			  "Setting TX MIC Key Failed\n");
 		return 0;
 	}

 	memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
 	/* XXX delete tx key on failure? */
 	return ath9k_hw_set_keycache_entry(ah, keyix + 32, hk, addr);
 }

 static int ath_reserve_key_cache_slot_tkip(struct ath_common *common)
 {
 	int i;

 	for (i = IEEE80211_WEP_NKID; i < common->keymax / 2; i++) {
 		if (test_bit(i, common->keymap) ||
 		    test_bit(i + 64, common->keymap))
 			continue; /* At least one part of TKIP key allocated */
 		if (common->splitmic &&
 		    (test_bit(i + 32, common->keymap) ||
 		     test_bit(i + 64 + 32, common->keymap)))
 			continue; /* At least one part of TKIP key allocated */

 		/* Found a free slot for a TKIP key */
 		return i;
 	}
 	return -1;
 }

 static int ath_reserve_key_cache_slot(struct ath_common *common)
 {
 	int i;

 	/* First, try to find slots that would not be available for TKIP. */
 	if (common->splitmic) {
 		for (i = IEEE80211_WEP_NKID; i < common->keymax / 4; i++) {
 			if (!test_bit(i, common->keymap) &&
 			    (test_bit(i + 32, common->keymap) ||
 			     test_bit(i + 64, common->keymap) ||
 			     test_bit(i + 64 + 32, common->keymap)))
 				return i;
 			if (!test_bit(i + 32, common->keymap) &&
 			    (test_bit(i, common->keymap) ||
 			     test_bit(i + 64, common->keymap) ||
 			     test_bit(i + 64 + 32, common->keymap)))
 				return i + 32;
 			if (!test_bit(i + 64, common->keymap) &&
 			    (test_bit(i , common->keymap) ||
 			     test_bit(i + 32, common->keymap) ||
 			     test_bit(i + 64 + 32, common->keymap)))
 				return i + 64;
 			if (!test_bit(i + 64 + 32, common->keymap) &&
 			    (test_bit(i, common->keymap) ||
 			     test_bit(i + 32, common->keymap) ||
 			     test_bit(i + 64, common->keymap)))
 				return i + 64 + 32;
 		}
 	} else {
 		for (i = IEEE80211_WEP_NKID; i < common->keymax / 2; i++) {
 			if (!test_bit(i, common->keymap) &&
 			    test_bit(i + 64, common->keymap))
 				return i;
 			if (test_bit(i, common->keymap) &&
 			    !test_bit(i + 64, common->keymap))
 				return i + 64;
 		}
 	}

 	/* No partially used TKIP slots, pick any available slot */
 	for (i = IEEE80211_WEP_NKID; i < common->keymax; i++) {
 		/* Do not allow slots that could be needed for TKIP group keys
 		 * to be used. This limitation could be removed if we know that
 		 * TKIP will not be used. */
 		if (i >= 64 && i < 64 + IEEE80211_WEP_NKID)
 			continue;
 		if (common->splitmic) {
 			if (i >= 32 && i < 32 + IEEE80211_WEP_NKID)
 				continue;
 			if (i >= 64 + 32 && i < 64 + 32 + IEEE80211_WEP_NKID)
 				continue;
 		}

 		if (!test_bit(i, common->keymap))
 			return i; /* Found a free slot for a key */
 	}

 	/* No free slot found */
 	return -1;
 }

 /*
  * Configure encryption in the HW.
  */
 int ath9k_cmn_key_config(struct ath_common *common,
 			 struct ieee80211_vif *vif,
 			 struct ieee80211_sta *sta,
 			 struct ieee80211_key_conf *key)
 {
 	struct ath_hw *ah = common->ah;
 	struct ath9k_keyval hk;
 	const u8 *mac = NULL;
 	int ret = 0;
 	int idx;

 	memset(&hk, 0, sizeof(hk));

 	switch (key->alg) {
 	case ALG_WEP:
 		hk.kv_type = ATH9K_CIPHER_WEP;
 		break;
 	case ALG_TKIP:
 		hk.kv_type = ATH9K_CIPHER_TKIP;
 		break;
 	case ALG_CCMP:
 		hk.kv_type = ATH9K_CIPHER_AES_CCM;
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	hk.kv_len = key->keylen;
 	memcpy(hk.kv_val, key->key, key->keylen);

 	if (!(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
 		/* For now, use the default keys for broadcast keys. This may
 		 * need to change with virtual interfaces. */
 		idx = key->keyidx;
 	} else if (key->keyidx) {
 		if (WARN_ON(!sta))
 			return -EOPNOTSUPP;
 		mac = sta->addr;

 		if (vif->type != NL80211_IFTYPE_AP) {
 			/* Only keyidx 0 should be used with unicast key, but
 			 * allow this for client mode for now. */
 			idx = key->keyidx;
 		} else
 			return -EIO;
 	} else {
 		if (WARN_ON(!sta))
 			return -EOPNOTSUPP;
 		mac = sta->addr;

 		if (key->alg == ALG_TKIP)
 			idx = ath_reserve_key_cache_slot_tkip(common);
 		else
 			idx = ath_reserve_key_cache_slot(common);
 		if (idx < 0)
 			return -ENOSPC; /* no free key cache entries */
 	}

 	if (key->alg == ALG_TKIP)
 		ret = ath_setkey_tkip(common, idx, key->key, &hk, mac,
 				      vif->type == NL80211_IFTYPE_AP);
 	else
 		ret = ath9k_hw_set_keycache_entry(ah, idx, &hk, mac);

 	if (!ret)
 		return -EIO;

 	set_bit(idx, common->keymap);
 	if (key->alg == ALG_TKIP) {
 		set_bit(idx + 64, common->keymap);
 		if (common->splitmic) {
 			set_bit(idx + 32, common->keymap);
 			set_bit(idx + 64 + 32, common->keymap);
 		}
 	}

 	return idx;
 }
 EXPORT_SYMBOL(ath9k_cmn_key_config);

 /*
  * Delete Key.
  */
 void ath9k_cmn_key_delete(struct ath_common *common,
 			  struct ieee80211_key_conf *key)
 {
 	struct ath_hw *ah = common->ah;

 	ath9k_hw_keyreset(ah, key->hw_key_idx);
 	if (key->hw_key_idx < IEEE80211_WEP_NKID)
 		return;

 	clear_bit(key->hw_key_idx, common->keymap);
 	if (key->alg != ALG_TKIP)
 		return;

 	clear_bit(key->hw_key_idx + 64, common->keymap);
 	if (common->splitmic) {
 		ath9k_hw_keyreset(ah, key->hw_key_idx + 32);
 		clear_bit(key->hw_key_idx + 32, common->keymap);
 		clear_bit(key->hw_key_idx + 64 + 32, common->keymap);
 	}
 }
 EXPORT_SYMBOL(ath9k_cmn_key_delete);

 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);
	/*
	* Copyright (c) 2009 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");

	/* Common RX processing */

	/* Assumes you've already done the endian to CPU conversion */
	static bool ath9k_rx_accept(struct ath_common *common,
	struct sk_buff *skb,
	struct ieee80211_rx_status *rxs,
	struct ath_rx_status *rx_stats,
	bool *decrypt_error)
	{
	struct ath_hw *ah = common->ah;
	struct ieee80211_hdr *hdr;
	__le16 fc;

	hdr = (struct ieee80211_hdr *) skb->data;
	fc = hdr->frame_control;

	if (!rx_stats->rs_datalen)
	return false;
	/*
	* rs_status follows rs_datalen so if rs_datalen is too large
	* we can take a hint that hardware corrupted it, so ignore
	* those frames.
	*/
	if (rx_stats->rs_datalen > common->rx_bufsize)
	return false;

	/*
	* rs_more indicates chained descriptors which can be used
	* to link buffers together for a sort of scatter-gather
	* operation.
	* reject the frame, we don't support scatter-gather yet and
	* the frame is probably corrupt anyway
	*/
	if (rx_stats->rs_more)
	return false;

	/*
	* 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) {
	if (rx_stats->rs_status & ATH9K_RXERR_CRC)
	rxs->flag \|= RX_FLAG_FAILED_FCS_CRC;
	if (rx_stats->rs_status & ATH9K_RXERR_PHY)
	return false;

	if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
	*decrypt_error = true;
	} else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
	if (ieee80211_is_ctl(fc))
	/*
	* Sometimes, we get invalid
	* MIC failures on valid control frames.
	* Remove these mic errors.
	*/
	rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
	else
	rxs->flag \|= RX_FLAG_MMIC_ERROR;
	}
	/*
	* Reject error frames with the exception of
	* decryption and MIC failures. For monitor mode,
	* we also ignore the CRC error.
	*/
	if (ah->opmode == NL80211_IFTYPE_MONITOR) {
	if (rx_stats->rs_status &
	~(ATH9K_RXERR_DECRYPT \| ATH9K_RXERR_MIC \|
	ATH9K_RXERR_CRC))
	return false;
	} else {
	if (rx_stats->rs_status &
	~(ATH9K_RXERR_DECRYPT \| ATH9K_RXERR_MIC)) {
	return false;
	}
	}
	}
	return true;
	}

	static int ath9k_process_rate(struct ath_common *common,
	struct ieee80211_hw *hw,
	struct ath_rx_status *rx_stats,
	struct ieee80211_rx_status *rxs,
	struct sk_buff *skb)
	{
	struct ieee80211_supported_band *sband;
	enum ieee80211_band band;
	unsigned int i = 0;

	band = hw->conf.channel->band;
	sband = hw->wiphy->bands[band];

	if (rx_stats->rs_rate & 0x80) {
	/* HT rate */
	rxs->flag \|= RX_FLAG_HT;
	if (rx_stats->rs_flags & ATH9K_RX_2040)
	rxs->flag \|= RX_FLAG_40MHZ;
	if (rx_stats->rs_flags & ATH9K_RX_GI)
	rxs->flag \|= RX_FLAG_SHORT_GI;
	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;
	}
	}

	/*
	* No valid hardware bitrate found -- we should not get here
	* because hardware has already validated this frame as OK.
	*/
	ath_print(common, ATH_DBG_XMIT, "unsupported hw bitrate detected "
	"0x%02x using 1 Mbit\n", rx_stats->rs_rate);
	if ((common->debug_mask & ATH_DBG_XMIT))
	print_hex_dump_bytes("", DUMP_PREFIX_NONE, skb->data, skb->len);

	return -EINVAL;
	}

	static void ath9k_process_rssi(struct ath_common *common,
	struct ieee80211_hw *hw,
	struct sk_buff *skb,
	struct ath_rx_status *rx_stats)
	{
	struct ath_hw *ah = common->ah;
	struct ieee80211_sta *sta;
	struct ieee80211_hdr *hdr;
	struct ath_node *an;
	int last_rssi = ATH_RSSI_DUMMY_MARKER;
	__le16 fc;

	hdr = (struct ieee80211_hdr *)skb->data;
	fc = hdr->frame_control;

	rcu_read_lock();
	/*
	* XXX: use ieee80211_find_sta! This requires quite a bit of work
	* under the current ath9k virtual wiphy implementation as we have
	* no way of tying a vif to wiphy. Typically vifs are attached to
	* at least one sdata of a wiphy on mac80211 but with ath9k virtual
	* wiphy you'd have to iterate over every wiphy and each sdata.
	*/
	sta = ieee80211_find_sta_by_hw(hw, hdr->addr2);
	if (sta) {
	an = (struct ath_node *) sta->drv_priv;
	if (rx_stats->rs_rssi != ATH9K_RSSI_BAD &&
	!rx_stats->rs_moreaggr)
	ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi);
	last_rssi = an->last_rssi;
	}
	rcu_read_unlock();

	if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
	rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
	ATH_RSSI_EP_MULTIPLIER);
	if (rx_stats->rs_rssi < 0)
	rx_stats->rs_rssi = 0;

	/* Update Beacon RSSI, this is used by ANI. */
	if (ieee80211_is_beacon(fc))
	ah->stats.avgbrssi = rx_stats->rs_rssi;
	}

	/*
	* For Decrypt or Demic errors, we only mark packet status here and always push
	* up the frame up to let mac80211 handle the actual error case, be it no
	* decryption key or real decryption error. This let us keep statistics there.
	*/
	int ath9k_cmn_rx_skb_preprocess(struct ath_common *common,
	struct ieee80211_hw *hw,
	struct sk_buff *skb,
	struct ath_rx_status *rx_stats,
	struct ieee80211_rx_status *rx_status,
	bool *decrypt_error)
	{
	struct ath_hw *ah = common->ah;

	memset(rx_status, 0, sizeof(struct ieee80211_rx_status));

	/*
	* everything but the rate is checked here, the rate check is done
	* separately to avoid doing two lookups for a rate for each frame.
	*/
	if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error))
	return -EINVAL;

	ath9k_process_rssi(common, hw, skb, rx_stats);

	if (ath9k_process_rate(common, hw, rx_stats, rx_status, skb))
	return -EINVAL;

	rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
	rx_status->band = hw->conf.channel->band;
	rx_status->freq = hw->conf.channel->center_freq;
	rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
	rx_status->antenna = rx_stats->rs_antenna;
	rx_status->flag \|= RX_FLAG_TSFT;

	return 0;
	}
	EXPORT_SYMBOL(ath9k_cmn_rx_skb_preprocess);

	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 = ath9k_cmn_padpos(hdr->frame_control);

	/* 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_padpos(__le16 frame_control)
	{
	int padpos = 24;
	if (ieee80211_has_a4(frame_control)) {
	padpos += ETH_ALEN;
	}
	if (ieee80211_is_data_qos(frame_control)) {
	padpos += IEEE80211_QOS_CTL_LEN;
	}

	return padpos;
	}
	EXPORT_SYMBOL(ath9k_cmn_padpos);

	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) {
	if (tx_info->control.hw_key->alg == ALG_WEP)
	return ATH9K_KEY_TYPE_WEP;
	else if (tx_info->control.hw_key->alg == ALG_TKIP)
	return ATH9K_KEY_TYPE_TKIP;
	else if (tx_info->control.hw_key->alg == ALG_CCMP)
	return ATH9K_KEY_TYPE_AES;
	}

	return ATH9K_KEY_TYPE_CLEAR;
	}
	EXPORT_SYMBOL(ath9k_cmn_get_hw_crypto_keytype);

	static u32 ath9k_get_extchanmode(struct ieee80211_channel *chan,
	enum nl80211_channel_type channel_type)
	{
	u32 chanmode = 0;

	switch (chan->band) {
	case IEEE80211_BAND_2GHZ:
	switch (channel_type) {
	case NL80211_CHAN_NO_HT:
	case NL80211_CHAN_HT20:
	chanmode = CHANNEL_G_HT20;
	break;
	case NL80211_CHAN_HT40PLUS:
	chanmode = CHANNEL_G_HT40PLUS;
	break;
	case NL80211_CHAN_HT40MINUS:
	chanmode = CHANNEL_G_HT40MINUS;
	break;
	}
	break;
	case IEEE80211_BAND_5GHZ:
	switch (channel_type) {
	case NL80211_CHAN_NO_HT:
	case NL80211_CHAN_HT20:
	chanmode = CHANNEL_A_HT20;
	break;
	case NL80211_CHAN_HT40PLUS:
	chanmode = CHANNEL_A_HT40PLUS;
	break;
	case NL80211_CHAN_HT40MINUS:
	chanmode = CHANNEL_A_HT40MINUS;
	break;
	}
	break;
	default:
	break;
	}

	return chanmode;
	}

	/*
	* Update internal channel flags.
	*/
	void ath9k_cmn_update_ichannel(struct ieee80211_hw *hw,
	struct ath9k_channel *ichan)
	{
	struct ieee80211_channel *chan = hw->conf.channel;
	struct ieee80211_conf *conf = &hw->conf;

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

	if (chan->band == IEEE80211_BAND_2GHZ) {
	ichan->chanmode = CHANNEL_G;
	ichan->channelFlags = CHANNEL_2GHZ \| CHANNEL_OFDM \| CHANNEL_G;
	} else {
	ichan->chanmode = CHANNEL_A;
	ichan->channelFlags = CHANNEL_5GHZ \| CHANNEL_OFDM;
	}

	if (conf_is_ht(conf))
	ichan->chanmode = ath9k_get_extchanmode(chan,
	conf->channel_type);
	}
	EXPORT_SYMBOL(ath9k_cmn_update_ichannel);

	/*
	* Get the internal channel reference.
	*/
	struct ath9k_channel ath9k_cmn_get_curchannel(struct ieee80211_hw hw,
	struct ath_hw *ah)
	{
	struct ieee80211_channel *curchan = hw->conf.channel;
	struct ath9k_channel *channel;
	u8 chan_idx;

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

	return channel;
	}
	EXPORT_SYMBOL(ath9k_cmn_get_curchannel);

	static int ath_setkey_tkip(struct ath_common common, u16 keyix, const u8 key,
	struct ath9k_keyval hk, const u8 addr,
	bool authenticator)
	{
	struct ath_hw *ah = common->ah;
	const u8 *key_rxmic;
	const u8 *key_txmic;

	key_txmic = key + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
	key_rxmic = key + NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;

	if (addr == NULL) {
	/*
	* Group key installation - only two key cache entries are used
	* regardless of splitmic capability since group key is only
	* used either for TX or RX.
	*/
	if (authenticator) {
	memcpy(hk->kv_mic, key_txmic, sizeof(hk->kv_mic));
	memcpy(hk->kv_txmic, key_txmic, sizeof(hk->kv_mic));
	} else {
	memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
	memcpy(hk->kv_txmic, key_rxmic, sizeof(hk->kv_mic));
	}
	return ath9k_hw_set_keycache_entry(ah, keyix, hk, addr);
	}
	if (!common->splitmic) {
	/* TX and RX keys share the same key cache entry. */
	memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
	memcpy(hk->kv_txmic, key_txmic, sizeof(hk->kv_txmic));
	return ath9k_hw_set_keycache_entry(ah, keyix, hk, addr);
	}

	/* Separate key cache entries for TX and RX */

	/* TX key goes at first index, RX key at +32. */
	memcpy(hk->kv_mic, key_txmic, sizeof(hk->kv_mic));
	if (!ath9k_hw_set_keycache_entry(ah, keyix, hk, NULL)) {
	/* TX MIC entry failed. No need to proceed further */
	ath_print(common, ATH_DBG_FATAL,
	"Setting TX MIC Key Failed\n");
	return 0;
	}

	memcpy(hk->kv_mic, key_rxmic, sizeof(hk->kv_mic));
	/* XXX delete tx key on failure? */
	return ath9k_hw_set_keycache_entry(ah, keyix + 32, hk, addr);
	}

	static int ath_reserve_key_cache_slot_tkip(struct ath_common *common)
	{
	int i;

	for (i = IEEE80211_WEP_NKID; i < common->keymax / 2; i++) {
	if (test_bit(i, common->keymap) \|\|
	test_bit(i + 64, common->keymap))
	continue; /* At least one part of TKIP key allocated */
	if (common->splitmic &&
	(test_bit(i + 32, common->keymap) \|\|
	test_bit(i + 64 + 32, common->keymap)))
	continue; /* At least one part of TKIP key allocated */

	/* Found a free slot for a TKIP key */
	return i;
	}
	return -1;
	}

	static int ath_reserve_key_cache_slot(struct ath_common *common)
	{
	int i;

	/* First, try to find slots that would not be available for TKIP. */
	if (common->splitmic) {
	for (i = IEEE80211_WEP_NKID; i < common->keymax / 4; i++) {
	if (!test_bit(i, common->keymap) &&
	(test_bit(i + 32, common->keymap) \|\|
	test_bit(i + 64, common->keymap) \|\|
	test_bit(i + 64 + 32, common->keymap)))
	return i;
	if (!test_bit(i + 32, common->keymap) &&
	(test_bit(i, common->keymap) \|\|
	test_bit(i + 64, common->keymap) \|\|
	test_bit(i + 64 + 32, common->keymap)))
	return i + 32;
	if (!test_bit(i + 64, common->keymap) &&
	(test_bit(i , common->keymap) \|\|
	test_bit(i + 32, common->keymap) \|\|
	test_bit(i + 64 + 32, common->keymap)))
	return i + 64;
	if (!test_bit(i + 64 + 32, common->keymap) &&
	(test_bit(i, common->keymap) \|\|
	test_bit(i + 32, common->keymap) \|\|
	test_bit(i + 64, common->keymap)))
	return i + 64 + 32;
	}
	} else {
	for (i = IEEE80211_WEP_NKID; i < common->keymax / 2; i++) {
	if (!test_bit(i, common->keymap) &&
	test_bit(i + 64, common->keymap))
	return i;
	if (test_bit(i, common->keymap) &&
	!test_bit(i + 64, common->keymap))
	return i + 64;
	}
	}

	/* No partially used TKIP slots, pick any available slot */
	for (i = IEEE80211_WEP_NKID; i < common->keymax; i++) {
	/* Do not allow slots that could be needed for TKIP group keys
	* to be used. This limitation could be removed if we know that
	* TKIP will not be used. */
	if (i >= 64 && i < 64 + IEEE80211_WEP_NKID)
	continue;
	if (common->splitmic) {
	if (i >= 32 && i < 32 + IEEE80211_WEP_NKID)
	continue;
	if (i >= 64 + 32 && i < 64 + 32 + IEEE80211_WEP_NKID)
	continue;
	}

	if (!test_bit(i, common->keymap))
	return i; /* Found a free slot for a key */
	}

	/* No free slot found */
	return -1;
	}

	/*
	* Configure encryption in the HW.
	*/
	int ath9k_cmn_key_config(struct ath_common *common,
	struct ieee80211_vif *vif,
	struct ieee80211_sta *sta,
	struct ieee80211_key_conf *key)
	{
	struct ath_hw *ah = common->ah;
	struct ath9k_keyval hk;
	const u8 *mac = NULL;
	int ret = 0;
	int idx;

	memset(&hk, 0, sizeof(hk));

	switch (key->alg) {
	case ALG_WEP:
	hk.kv_type = ATH9K_CIPHER_WEP;
	break;
	case ALG_TKIP:
	hk.kv_type = ATH9K_CIPHER_TKIP;
	break;
	case ALG_CCMP:
	hk.kv_type = ATH9K_CIPHER_AES_CCM;
	break;
	default:
	return -EOPNOTSUPP;
	}

	hk.kv_len = key->keylen;
	memcpy(hk.kv_val, key->key, key->keylen);

	if (!(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
	/* For now, use the default keys for broadcast keys. This may
	* need to change with virtual interfaces. */
	idx = key->keyidx;
	} else if (key->keyidx) {
	if (WARN_ON(!sta))
	return -EOPNOTSUPP;
	mac = sta->addr;

	if (vif->type != NL80211_IFTYPE_AP) {
	/* Only keyidx 0 should be used with unicast key, but
	* allow this for client mode for now. */
	idx = key->keyidx;
	} else
	return -EIO;
	} else {
	if (WARN_ON(!sta))
	return -EOPNOTSUPP;
	mac = sta->addr;

	if (key->alg == ALG_TKIP)
	idx = ath_reserve_key_cache_slot_tkip(common);
	else
	idx = ath_reserve_key_cache_slot(common);
	if (idx < 0)
	return -ENOSPC; /* no free key cache entries */
	}

	if (key->alg == ALG_TKIP)
	ret = ath_setkey_tkip(common, idx, key->key, &hk, mac,
	vif->type == NL80211_IFTYPE_AP);
	else
	ret = ath9k_hw_set_keycache_entry(ah, idx, &hk, mac);

	if (!ret)
	return -EIO;

	set_bit(idx, common->keymap);
	if (key->alg == ALG_TKIP) {
	set_bit(idx + 64, common->keymap);
	if (common->splitmic) {
	set_bit(idx + 32, common->keymap);
	set_bit(idx + 64 + 32, common->keymap);
	}
	}

	return idx;
	}
	EXPORT_SYMBOL(ath9k_cmn_key_config);

	/*
	* Delete Key.
	*/
	void ath9k_cmn_key_delete(struct ath_common *common,
	struct ieee80211_key_conf *key)
	{
	struct ath_hw *ah = common->ah;

	ath9k_hw_keyreset(ah, key->hw_key_idx);
	if (key->hw_key_idx < IEEE80211_WEP_NKID)
	return;

	clear_bit(key->hw_key_idx, common->keymap);
	if (key->alg != ALG_TKIP)
	return;

	clear_bit(key->hw_key_idx + 64, common->keymap);
	if (common->splitmic) {
	ath9k_hw_keyreset(ah, key->hw_key_idx + 32);
	clear_bit(key->hw_key_idx + 32, common->keymap);
	clear_bit(key->hw_key_idx + 64 + 32, common->keymap);
	}
	}
	EXPORT_SYMBOL(ath9k_cmn_key_delete);

	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);