From 52409fae3e4b8d16b68b61902fc09075cd97b75d Mon Sep 17 00:00:00 2001 From: Dominik Sliwa Date: Sun, 2 Jul 2017 16:41:37 +0200 Subject: Backports generated from 4.11 kernel Initial commit. Signed-off-by: Dominik Sliwa --- drivers/net/wireless/ath/ath9k/dfs.c | 363 +++++++++++++++++++++++++++++++++++ 1 file changed, 363 insertions(+) create mode 100644 drivers/net/wireless/ath/ath9k/dfs.c (limited to 'drivers/net/wireless/ath/ath9k/dfs.c') diff --git a/drivers/net/wireless/ath/ath9k/dfs.c b/drivers/net/wireless/ath/ath9k/dfs.c new file mode 100644 index 0000000..1ece42c --- /dev/null +++ b/drivers/net/wireless/ath/ath9k/dfs.c @@ -0,0 +1,363 @@ +/* + * Copyright (c) 2008-2011 Atheros Communications Inc. + * Copyright (c) 2011 Neratec Solutions AG + * + * 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. + */ + +#include "hw.h" +#include "hw-ops.h" +#include "ath9k.h" +#include "dfs.h" +#include "dfs_debug.h" + +/* internal struct to pass radar data */ +struct ath_radar_data { + u8 pulse_bw_info; + u8 rssi; + u8 ext_rssi; + u8 pulse_length_ext; + u8 pulse_length_pri; +}; + +/**** begin: CHIRP ************************************************************/ + +/* min and max gradients for defined FCC chirping pulses, given by + * - 20MHz chirp width over a pulse width of 50us + * - 5MHz chirp width over a pulse width of 100us + */ +static const int BIN_DELTA_MIN = 1; +static const int BIN_DELTA_MAX = 10; + +/* we need at least 3 deltas / 4 samples for a reliable chirp detection */ +#define NUM_DIFFS 3 +static const int FFT_NUM_SAMPLES = (NUM_DIFFS + 1); + +/* Threshold for difference of delta peaks */ +static const int MAX_DIFF = 2; + +/* width range to be checked for chirping */ +static const int MIN_CHIRP_PULSE_WIDTH = 20; +static const int MAX_CHIRP_PULSE_WIDTH = 110; + +struct ath9k_dfs_fft_20 { + u8 bin[28]; + u8 lower_bins[3]; +} __packed; +struct ath9k_dfs_fft_40 { + u8 bin[64]; + u8 lower_bins[3]; + u8 upper_bins[3]; +} __packed; + +static inline int fft_max_index(u8 *bins) +{ + return (bins[2] & 0xfc) >> 2; +} +static inline int fft_max_magnitude(u8 *bins) +{ + return (bins[0] & 0xc0) >> 6 | bins[1] << 2 | (bins[2] & 0x03) << 10; +} +static inline u8 fft_bitmap_weight(u8 *bins) +{ + return bins[0] & 0x3f; +} + +static int ath9k_get_max_index_ht40(struct ath9k_dfs_fft_40 *fft, + bool is_ctl, bool is_ext) +{ + const int DFS_UPPER_BIN_OFFSET = 64; + /* if detected radar on both channels, select the significant one */ + if (is_ctl && is_ext) { + /* first check wether channels have 'strong' bins */ + is_ctl = fft_bitmap_weight(fft->lower_bins) != 0; + is_ext = fft_bitmap_weight(fft->upper_bins) != 0; + + /* if still unclear, take higher magnitude */ + if (is_ctl && is_ext) { + int mag_lower = fft_max_magnitude(fft->lower_bins); + int mag_upper = fft_max_magnitude(fft->upper_bins); + if (mag_upper > mag_lower) + is_ctl = false; + else + is_ext = false; + } + } + if (is_ctl) + return fft_max_index(fft->lower_bins); + return fft_max_index(fft->upper_bins) + DFS_UPPER_BIN_OFFSET; +} +static bool ath9k_check_chirping(struct ath_softc *sc, u8 *data, + int datalen, bool is_ctl, bool is_ext) +{ + int i; + int max_bin[FFT_NUM_SAMPLES]; + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + int prev_delta; + + if (IS_CHAN_HT40(ah->curchan)) { + struct ath9k_dfs_fft_40 *fft = (struct ath9k_dfs_fft_40 *) data; + int num_fft_packets = datalen / sizeof(*fft); + if (num_fft_packets == 0) + return false; + + ath_dbg(common, DFS, "HT40: datalen=%d, num_fft_packets=%d\n", + datalen, num_fft_packets); + if (num_fft_packets < (FFT_NUM_SAMPLES)) { + ath_dbg(common, DFS, "not enough packets for chirp\n"); + return false; + } + /* HW sometimes adds 2 garbage bytes in front of FFT samples */ + if ((datalen % sizeof(*fft)) == 2) { + fft = (struct ath9k_dfs_fft_40 *) (data + 2); + ath_dbg(common, DFS, "fixing datalen by 2\n"); + } + if (IS_CHAN_HT40MINUS(ah->curchan)) { + int temp = is_ctl; + is_ctl = is_ext; + is_ext = temp; + } + for (i = 0; i < FFT_NUM_SAMPLES; i++) + max_bin[i] = ath9k_get_max_index_ht40(fft + i, is_ctl, + is_ext); + } else { + struct ath9k_dfs_fft_20 *fft = (struct ath9k_dfs_fft_20 *) data; + int num_fft_packets = datalen / sizeof(*fft); + if (num_fft_packets == 0) + return false; + ath_dbg(common, DFS, "HT20: datalen=%d, num_fft_packets=%d\n", + datalen, num_fft_packets); + if (num_fft_packets < (FFT_NUM_SAMPLES)) { + ath_dbg(common, DFS, "not enough packets for chirp\n"); + return false; + } + /* in ht20, this is a 6-bit signed number => shift it to 0 */ + for (i = 0; i < FFT_NUM_SAMPLES; i++) + max_bin[i] = fft_max_index(fft[i].lower_bins) ^ 0x20; + } + ath_dbg(common, DFS, "bin_max = [%d, %d, %d, %d]\n", + max_bin[0], max_bin[1], max_bin[2], max_bin[3]); + + /* Check for chirp attributes within specs + * a) delta of adjacent max_bins is within range + * b) delta of adjacent deltas are within tolerance + */ + prev_delta = 0; + for (i = 0; i < NUM_DIFFS; i++) { + int ddelta = -1; + int delta = max_bin[i + 1] - max_bin[i]; + + /* ensure gradient is within valid range */ + if (abs(delta) < BIN_DELTA_MIN || abs(delta) > BIN_DELTA_MAX) { + ath_dbg(common, DFS, "CHIRP: invalid delta %d " + "in sample %d\n", delta, i); + return false; + } + if (i == 0) + goto done; + ddelta = delta - prev_delta; + if (abs(ddelta) > MAX_DIFF) { + ath_dbg(common, DFS, "CHIRP: ddelta %d too high\n", + ddelta); + return false; + } +done: + ath_dbg(common, DFS, "CHIRP - %d: delta=%d, ddelta=%d\n", + i, delta, ddelta); + prev_delta = delta; + } + return true; +} +/**** end: CHIRP **************************************************************/ + +/* convert pulse duration to usecs, considering clock mode */ +static u32 dur_to_usecs(struct ath_hw *ah, u32 dur) +{ + const u32 AR93X_NSECS_PER_DUR = 800; + const u32 AR93X_NSECS_PER_DUR_FAST = (8000 / 11); + u32 nsecs; + + if (IS_CHAN_A_FAST_CLOCK(ah, ah->curchan)) + nsecs = dur * AR93X_NSECS_PER_DUR_FAST; + else + nsecs = dur * AR93X_NSECS_PER_DUR; + + return (nsecs + 500) / 1000; +} + +#define PRI_CH_RADAR_FOUND 0x01 +#define EXT_CH_RADAR_FOUND 0x02 +static bool +ath9k_postprocess_radar_event(struct ath_softc *sc, + struct ath_radar_data *ard, + struct pulse_event *pe) +{ + u8 rssi; + u16 dur; + + /* + * Only the last 2 bits of the BW info are relevant, they indicate + * which channel the radar was detected in. + */ + ard->pulse_bw_info &= 0x03; + + switch (ard->pulse_bw_info) { + case PRI_CH_RADAR_FOUND: + /* radar in ctrl channel */ + dur = ard->pulse_length_pri; + DFS_STAT_INC(sc, pri_phy_errors); + /* + * cannot use ctrl channel RSSI + * if extension channel is stronger + */ + rssi = (ard->ext_rssi >= (ard->rssi + 3)) ? 0 : ard->rssi; + break; + case EXT_CH_RADAR_FOUND: + /* radar in extension channel */ + dur = ard->pulse_length_ext; + DFS_STAT_INC(sc, ext_phy_errors); + /* + * cannot use extension channel RSSI + * if control channel is stronger + */ + rssi = (ard->rssi >= (ard->ext_rssi + 12)) ? 0 : ard->ext_rssi; + break; + case (PRI_CH_RADAR_FOUND | EXT_CH_RADAR_FOUND): + /* + * Conducted testing, when pulse is on DC, both pri and ext + * durations are reported to be same + * + * Radiated testing, when pulse is on DC, different pri and + * ext durations are reported, so take the larger of the two + */ + if (ard->pulse_length_ext >= ard->pulse_length_pri) + dur = ard->pulse_length_ext; + else + dur = ard->pulse_length_pri; + DFS_STAT_INC(sc, dc_phy_errors); + + /* when both are present use stronger one */ + rssi = (ard->rssi < ard->ext_rssi) ? ard->ext_rssi : ard->rssi; + break; + default: + /* + * Bogus bandwidth info was received in descriptor, + * so ignore this PHY error + */ + DFS_STAT_INC(sc, bwinfo_discards); + return false; + } + + if (rssi == 0) { + DFS_STAT_INC(sc, rssi_discards); + return false; + } + + /* convert duration to usecs */ + pe->width = dur_to_usecs(sc->sc_ah, dur); + pe->rssi = rssi; + + DFS_STAT_INC(sc, pulses_detected); + return true; +} + +static void +ath9k_dfs_process_radar_pulse(struct ath_softc *sc, struct pulse_event *pe) +{ + struct dfs_pattern_detector *pd = sc->dfs_detector; + DFS_STAT_INC(sc, pulses_processed); + if (pd == NULL) + return; + if (!pd->add_pulse(pd, pe)) + return; + DFS_STAT_INC(sc, radar_detected); + ieee80211_radar_detected(sc->hw); +} + +/* + * DFS: check PHY-error for radar pulse and feed the detector + */ +void ath9k_dfs_process_phyerr(struct ath_softc *sc, void *data, + struct ath_rx_status *rs, u64 mactime) +{ + struct ath_radar_data ard; + u16 datalen; + char *vdata_end; + struct pulse_event pe; + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + + DFS_STAT_INC(sc, pulses_total); + if ((rs->rs_phyerr != ATH9K_PHYERR_RADAR) && + (rs->rs_phyerr != ATH9K_PHYERR_FALSE_RADAR_EXT)) { + ath_dbg(common, DFS, + "Error: rs_phyer=0x%x not a radar error\n", + rs->rs_phyerr); + DFS_STAT_INC(sc, pulses_no_dfs); + return; + } + + datalen = rs->rs_datalen; + if (datalen == 0) { + DFS_STAT_INC(sc, datalen_discards); + return; + } + + ard.rssi = rs->rs_rssi_ctl[0]; + ard.ext_rssi = rs->rs_rssi_ext[0]; + + /* + * hardware stores this as 8 bit signed value. + * we will cap it at 0 if it is a negative number + */ + if (ard.rssi & 0x80) + ard.rssi = 0; + if (ard.ext_rssi & 0x80) + ard.ext_rssi = 0; + + vdata_end = (char *)data + datalen; + ard.pulse_bw_info = vdata_end[-1]; + ard.pulse_length_ext = vdata_end[-2]; + ard.pulse_length_pri = vdata_end[-3]; + pe.freq = ah->curchan->channel; + pe.ts = mactime; + if (!ath9k_postprocess_radar_event(sc, &ard, &pe)) + return; + + if (pe.width > MIN_CHIRP_PULSE_WIDTH && + pe.width < MAX_CHIRP_PULSE_WIDTH) { + bool is_ctl = !!(ard.pulse_bw_info & PRI_CH_RADAR_FOUND); + bool is_ext = !!(ard.pulse_bw_info & EXT_CH_RADAR_FOUND); + int clen = datalen - 3; + pe.chirp = ath9k_check_chirping(sc, data, clen, is_ctl, is_ext); + } else { + pe.chirp = false; + } + + ath_dbg(common, DFS, + "ath9k_dfs_process_phyerr: type=%d, freq=%d, ts=%llu, " + "width=%d, rssi=%d, delta_ts=%llu\n", + ard.pulse_bw_info, pe.freq, pe.ts, pe.width, pe.rssi, + pe.ts - sc->dfs_prev_pulse_ts); + sc->dfs_prev_pulse_ts = pe.ts; + if (ard.pulse_bw_info & PRI_CH_RADAR_FOUND) + ath9k_dfs_process_radar_pulse(sc, &pe); + if (IS_CHAN_HT40(ah->curchan) && + ard.pulse_bw_info & EXT_CH_RADAR_FOUND) { + pe.freq += IS_CHAN_HT40PLUS(ah->curchan) ? 20 : -20; + ath9k_dfs_process_radar_pulse(sc, &pe); + } +} +#undef PRI_CH_RADAR_FOUND +#undef EXT_CH_RADAR_FOUND -- cgit v1.2.3