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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/net/wireless/ath/ath9k/dfs.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/net/wireless/ath/ath9k/dfs.c')
-rw-r--r--drivers/net/wireless/ath/ath9k/dfs.c361
1 files changed, 361 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath9k/dfs.c b/drivers/net/wireless/ath/ath9k/dfs.c
new file mode 100644
index 000000000..11349218b
--- /dev/null
+++ b/drivers/net/wireless/ath/ath9k/dfs.c
@@ -0,0 +1,361 @@
+/*
+ * 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
+#define 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))
+ swap(is_ctl, is_ext);
+
+ 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 = max(ard->rssi, ard->ext_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, NULL))
+ 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 = 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