drivers/net/wireless/ath/ath9k/common.c - vendor/opensource/backports - Git at Google

 /*
  * 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_rx &&
 	    (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);
	/*
	* 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_rx &&
	(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);