1 files changed, 286 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/common.c b/drivers/net/wireless/ath/ath9k/common.c
new file mode 100644
index 0000000..2f1e161
--- /dev/null
+++ b/drivers/net/wireless/ath/ath9k/common.c
@@ -0,0 +1,286 @@
+/*
+ * 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.
+	 *
+	 * 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_more && 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 u8 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;
+		return rx_stats->rs_rate & 0x7f;
+	}
+
+	for (i = 0; i < sband->n_bitrates; i++) {
+		if (sband->bitrates[i].hw_value == rx_stats->rs_rate)
+			return i;
+		if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
+			rxs->flag |= RX_FLAG_SHORTPRE;
+			return i;
+		}
+	}
+
+	/* No valid hardware bitrate found -- we should not get here */
+	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 0;
+}
+
+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;
+	else if (rx_stats->rs_rssi > 127)
+		rx_stats->rs_rssi = 127;
+
+	/* 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));
+	if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error))
+		return -EINVAL;
+
+	ath9k_process_rssi(common, hw, skb, rx_stats);
+
+	rx_status->rate_idx = ath9k_process_rate(common, hw,
+						 rx_stats, rx_status, skb);
+	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->noise = common->ani.noise_floor;
+	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, 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;
+
+	/* 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 - hdrlen % 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 = hdrlen & 3;
+	if (padsize && hdrlen >= 24) {
+		memmove(skb->data + padsize, skb->data, hdrlen);
+		skb_pull(skb, padsize);
+	}
+
+	keyix = rx_stats->rs_keyix;
+
+	if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
+		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);
+
+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);