2 * Copyright (c) 2009 Atheros Communications Inc.
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 * Module for common driver code between ath9k and ath9k_htc
21 #include <linux/kernel.h>
22 #include <linux/module.h>
26 MODULE_AUTHOR("Atheros Communications");
27 MODULE_DESCRIPTION("Shared library for Atheros wireless 802.11n LAN cards.");
28 MODULE_LICENSE("Dual BSD/GPL");
30 /* Common RX processing */
32 /* Assumes you've already done the endian to CPU conversion */
33 static bool ath9k_rx_accept(struct ath_common *common,
35 struct ieee80211_rx_status *rxs,
36 struct ath_rx_status *rx_stats,
39 struct ath_hw *ah = common->ah;
40 struct ieee80211_hdr *hdr;
43 hdr = (struct ieee80211_hdr *) skb->data;
44 fc = hdr->frame_control;
46 if (!rx_stats->rs_datalen)
49 * rs_status follows rs_datalen so if rs_datalen is too large
50 * we can take a hint that hardware corrupted it, so ignore
53 if (rx_stats->rs_datalen > common->rx_bufsize)
57 * rs_more indicates chained descriptors which can be used
58 * to link buffers together for a sort of scatter-gather
61 * The rx_stats->rs_status will not be set until the end of the
62 * chained descriptors so it can be ignored if rs_more is set. The
63 * rs_more will be false at the last element of the chained
66 if (!rx_stats->rs_more && rx_stats->rs_status != 0) {
67 if (rx_stats->rs_status & ATH9K_RXERR_CRC)
68 rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
69 if (rx_stats->rs_status & ATH9K_RXERR_PHY)
72 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
73 *decrypt_error = true;
74 } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
75 if (ieee80211_is_ctl(fc))
77 * Sometimes, we get invalid
78 * MIC failures on valid control frames.
79 * Remove these mic errors.
81 rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
83 rxs->flag |= RX_FLAG_MMIC_ERROR;
86 * Reject error frames with the exception of
87 * decryption and MIC failures. For monitor mode,
88 * we also ignore the CRC error.
90 if (ah->opmode == NL80211_IFTYPE_MONITOR) {
91 if (rx_stats->rs_status &
92 ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
96 if (rx_stats->rs_status &
97 ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
105 static u8 ath9k_process_rate(struct ath_common *common,
106 struct ieee80211_hw *hw,
107 struct ath_rx_status *rx_stats,
108 struct ieee80211_rx_status *rxs,
111 struct ieee80211_supported_band *sband;
112 enum ieee80211_band band;
115 band = hw->conf.channel->band;
116 sband = hw->wiphy->bands[band];
118 if (rx_stats->rs_rate & 0x80) {
120 rxs->flag |= RX_FLAG_HT;
121 if (rx_stats->rs_flags & ATH9K_RX_2040)
122 rxs->flag |= RX_FLAG_40MHZ;
123 if (rx_stats->rs_flags & ATH9K_RX_GI)
124 rxs->flag |= RX_FLAG_SHORT_GI;
125 return rx_stats->rs_rate & 0x7f;
128 for (i = 0; i < sband->n_bitrates; i++) {
129 if (sband->bitrates[i].hw_value == rx_stats->rs_rate)
131 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
132 rxs->flag |= RX_FLAG_SHORTPRE;
137 /* No valid hardware bitrate found -- we should not get here */
138 ath_print(common, ATH_DBG_XMIT, "unsupported hw bitrate detected "
139 "0x%02x using 1 Mbit\n", rx_stats->rs_rate);
140 if ((common->debug_mask & ATH_DBG_XMIT))
141 print_hex_dump_bytes("", DUMP_PREFIX_NONE, skb->data, skb->len);
146 static void ath9k_process_rssi(struct ath_common *common,
147 struct ieee80211_hw *hw,
149 struct ath_rx_status *rx_stats)
151 struct ath_hw *ah = common->ah;
152 struct ieee80211_sta *sta;
153 struct ieee80211_hdr *hdr;
155 int last_rssi = ATH_RSSI_DUMMY_MARKER;
158 hdr = (struct ieee80211_hdr *)skb->data;
159 fc = hdr->frame_control;
163 * XXX: use ieee80211_find_sta! This requires quite a bit of work
164 * under the current ath9k virtual wiphy implementation as we have
165 * no way of tying a vif to wiphy. Typically vifs are attached to
166 * at least one sdata of a wiphy on mac80211 but with ath9k virtual
167 * wiphy you'd have to iterate over every wiphy and each sdata.
169 sta = ieee80211_find_sta_by_hw(hw, hdr->addr2);
171 an = (struct ath_node *) sta->drv_priv;
172 if (rx_stats->rs_rssi != ATH9K_RSSI_BAD &&
173 !rx_stats->rs_moreaggr)
174 ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi);
175 last_rssi = an->last_rssi;
179 if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
180 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
181 ATH_RSSI_EP_MULTIPLIER);
182 if (rx_stats->rs_rssi < 0)
183 rx_stats->rs_rssi = 0;
185 /* Update Beacon RSSI, this is used by ANI. */
186 if (ieee80211_is_beacon(fc))
187 ah->stats.avgbrssi = rx_stats->rs_rssi;
191 * For Decrypt or Demic errors, we only mark packet status here and always push
192 * up the frame up to let mac80211 handle the actual error case, be it no
193 * decryption key or real decryption error. This let us keep statistics there.
195 int ath9k_cmn_rx_skb_preprocess(struct ath_common *common,
196 struct ieee80211_hw *hw,
198 struct ath_rx_status *rx_stats,
199 struct ieee80211_rx_status *rx_status,
202 struct ath_hw *ah = common->ah;
204 memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
205 if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error))
208 ath9k_process_rssi(common, hw, skb, rx_stats);
210 rx_status->rate_idx = ath9k_process_rate(common, hw,
211 rx_stats, rx_status, skb);
212 rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
213 rx_status->band = hw->conf.channel->band;
214 rx_status->freq = hw->conf.channel->center_freq;
215 rx_status->noise = common->ani.noise_floor;
216 rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
217 rx_status->antenna = rx_stats->rs_antenna;
218 rx_status->flag |= RX_FLAG_TSFT;
222 EXPORT_SYMBOL(ath9k_cmn_rx_skb_preprocess);
224 void ath9k_cmn_rx_skb_postprocess(struct ath_common *common,
226 struct ath_rx_status *rx_stats,
227 struct ieee80211_rx_status *rxs,
230 struct ath_hw *ah = common->ah;
231 struct ieee80211_hdr *hdr;
232 int hdrlen, padpos, padsize;
236 /* see if any padding is done by the hw and remove it */
237 hdr = (struct ieee80211_hdr *) skb->data;
238 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
239 fc = hdr->frame_control;
240 padpos = ath9k_cmn_padpos(hdr->frame_control);
242 /* The MAC header is padded to have 32-bit boundary if the
243 * packet payload is non-zero. The general calculation for
244 * padsize would take into account odd header lengths:
245 * padsize = (4 - padpos % 4) % 4; However, since only
246 * even-length headers are used, padding can only be 0 or 2
247 * bytes and we can optimize this a bit. In addition, we must
248 * not try to remove padding from short control frames that do
249 * not have payload. */
250 padsize = padpos & 3;
251 if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
252 memmove(skb->data + padsize, skb->data, padpos);
253 skb_pull(skb, padsize);
256 keyix = rx_stats->rs_keyix;
258 if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
259 rxs->flag |= RX_FLAG_DECRYPTED;
260 } else if (ieee80211_has_protected(fc)
261 && !decrypt_error && skb->len >= hdrlen + 4) {
262 keyix = skb->data[hdrlen + 3] >> 6;
264 if (test_bit(keyix, common->keymap))
265 rxs->flag |= RX_FLAG_DECRYPTED;
267 if (ah->sw_mgmt_crypto &&
268 (rxs->flag & RX_FLAG_DECRYPTED) &&
269 ieee80211_is_mgmt(fc))
270 /* Use software decrypt for management frames. */
271 rxs->flag &= ~RX_FLAG_DECRYPTED;
273 EXPORT_SYMBOL(ath9k_cmn_rx_skb_postprocess);
275 int ath9k_cmn_padpos(__le16 frame_control)
278 if (ieee80211_has_a4(frame_control)) {
281 if (ieee80211_is_data_qos(frame_control)) {
282 padpos += IEEE80211_QOS_CTL_LEN;
287 EXPORT_SYMBOL(ath9k_cmn_padpos);
289 static int __init ath9k_cmn_init(void)
293 module_init(ath9k_cmn_init);
295 static void __exit ath9k_cmn_exit(void)
299 module_exit(ath9k_cmn_exit);