6 files changed, 430 insertions, 8 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index fb49deda3346..486a6b8f3c97 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -5899,6 +5899,65 @@ void iwl_mvm_mac_flush_sta(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 	mutex_unlock(&mvm->mutex);
 }
 
+static int iwl_mvm_mac_get_acs_survey(struct iwl_mvm *mvm, int idx,
+				      struct survey_info *survey)
+{
+	int chan_idx;
+	enum nl80211_band band;
+	int ret;
+
+	mutex_lock(&mvm->mutex);
+
+	if (!mvm->acs_survey) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	/* Find and return the next entry that has a non-zero active time */
+	for (band = 0; band < NUM_NL80211_BANDS; band++) {
+		struct ieee80211_supported_band *sband =
+			mvm->hw->wiphy->bands[band];
+
+		if (!sband)
+			continue;
+
+		for (chan_idx = 0; chan_idx < sband->n_channels; chan_idx++) {
+			struct iwl_mvm_acs_survey_channel *info =
+				&mvm->acs_survey->bands[band][chan_idx];
+
+			if (!info->time)
+				continue;
+
+			/* Found (the next) channel to report */
+			survey->channel = &sband->channels[chan_idx];
+			survey->filled = SURVEY_INFO_TIME |
+					 SURVEY_INFO_TIME_BUSY |
+					 SURVEY_INFO_TIME_RX |
+					 SURVEY_INFO_TIME_TX;
+			survey->time = info->time;
+			survey->time_busy = info->time_busy;
+			survey->time_rx = info->time_rx;
+			survey->time_tx = info->time_tx;
+			survey->noise = info->noise;
+			if (survey->noise < 0)
+				survey->filled |= SURVEY_INFO_NOISE_DBM;
+
+			/* Clear time so that channel is only reported once */
+			info->time = 0;
+
+			ret = 0;
+			goto out;
+		}
+	}
+
+	ret = -ENOENT;
+
+out:
+	mutex_unlock(&mvm->mutex);
+
+	return ret;
+}
+
 int iwl_mvm_mac_get_survey(struct ieee80211_hw *hw, int idx,
 			   struct survey_info *survey)
 {
@@ -5911,14 +5970,18 @@ int iwl_mvm_mac_get_survey(struct ieee80211_hw *hw, int idx,
 
 	memset(survey, 0, sizeof(*survey));
 
-	/* only support global statistics right now */
-	if (idx != 0)
-		return -ENOENT;
-
 	if (!fw_has_capa(&mvm->fw->ucode_capa,
 			 IWL_UCODE_TLV_CAPA_RADIO_BEACON_STATS))
 		return -ENOENT;
 
+	/*
+	 * Return the beacon stats at index zero and pass on following indices
+	 * to the function returning the full survey, most likely for ACS
+	 * (Automatic Channel Selection).
+	 */
+	if (idx > 0)
+		return iwl_mvm_mac_get_acs_survey(mvm, idx - 1, survey);
+
 	mutex_lock(&mvm->mutex);
 
 	if (iwl_mvm_firmware_running(mvm)) {
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index b292276de4ae..b96568f5640c 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -918,6 +918,35 @@ struct iwl_mei_scan_filter {
 	struct work_struct scan_work;
 };
 
+/**
+ * struct iwl_mvm_acs_survey_channel - per-channel survey information
+ *
+ * Stripped down version of &struct survey_info.
+ *
+ * @time: time in ms the radio was on the channel
+ * @time_busy: time in ms the channel was sensed busy
+ * @time_tx: time in ms spent transmitting data
+ * @time_rx: time in ms spent receiving data
+ * @noise: channel noise in dBm
+ */
+struct iwl_mvm_acs_survey_channel {
+	u32 time;
+	u32 time_busy;
+	u32 time_tx;
+	u32 time_rx;
+	s8 noise;
+};
+
+struct iwl_mvm_acs_survey {
+	struct iwl_mvm_acs_survey_channel *bands[NUM_NL80211_BANDS];
+
+	/* Overall number of channels */
+	int n_channels;
+
+	/* Storage space for per-channel information follows */
+	struct iwl_mvm_acs_survey_channel channels[] __counted_by(n_channels);
+};
+
 struct iwl_mvm {
 	/* for logger access */
 	struct device *dev;
@@ -1287,6 +1316,8 @@ struct iwl_mvm {
 
 	struct iwl_mei_scan_filter mei_scan_filter;
 
+	struct iwl_mvm_acs_survey *acs_survey;
+
 	bool statistics_clear;
 };
 
@@ -2033,6 +2064,8 @@ unsigned int iwl_mvm_get_link_grade(struct ieee80211_bss_conf *link_conf);
 bool iwl_mvm_mld_valid_link_pair(struct ieee80211_vif *vif,
 				 const struct iwl_mvm_link_sel_data *a,
 				 const struct iwl_mvm_link_sel_data *b);
+
+s8 iwl_mvm_average_dbm_values(const struct iwl_umac_scan_channel_survey_notif *notif);
 #endif
 
 /* AP and IBSS */
@@ -2115,6 +2148,8 @@ int iwl_mvm_max_scan_ie_len(struct iwl_mvm *mvm);
 void iwl_mvm_report_scan_aborted(struct iwl_mvm *mvm);
 void iwl_mvm_scan_timeout_wk(struct work_struct *work);
 int iwl_mvm_int_mlo_scan(struct iwl_mvm *mvm, struct ieee80211_vif *vif);
+void iwl_mvm_rx_channel_survey_notif(struct iwl_mvm *mvm,
+				     struct iwl_rx_cmd_buffer *rxb);
 
 /* Scheduled scan */
 void iwl_mvm_rx_lmac_scan_complete_notif(struct iwl_mvm *mvm,
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
index c52e69743c80..53283d052e18 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@@ -473,6 +473,9 @@ static const struct iwl_rx_handlers iwl_mvm_rx_handlers[] = {
 	RX_HANDLER_GRP(MAC_CONF_GROUP, ROC_NOTIF,
 		       iwl_mvm_rx_roc_notif, RX_HANDLER_SYNC,
 		       struct iwl_roc_notif),
+	RX_HANDLER_GRP(SCAN_GROUP, CHANNEL_SURVEY_NOTIF,
+		       iwl_mvm_rx_channel_survey_notif, RX_HANDLER_ASYNC_LOCKED,
+		       struct iwl_umac_scan_channel_survey_notif),
 };
 #undef RX_HANDLER
 #undef RX_HANDLER_GRP
@@ -1582,6 +1585,7 @@ static void iwl_op_mode_mvm_stop(struct iwl_op_mode *op_mode)
 	kfree(mvm->temp_nvm_data);
 	for (i = 0; i < NVM_MAX_NUM_SECTIONS; i++)
 		kfree(mvm->nvm_sections[i].data);
+	kfree(mvm->acs_survey);
 
 	cancel_delayed_work_sync(&mvm->tcm.work);
 
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/scan.c b/drivers/net/wireless/intel/iwlwifi/mvm/scan.c
index 49ec515b5bad..a7ec172eeade 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/scan.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/scan.c
@@ -226,6 +226,14 @@ iwl_mvm_scan_type _iwl_mvm_get_scan_type(struct iwl_mvm *mvm,
 		.global_cnt = 0,
 	};
 
+	/*
+	 * A scanning AP interface probably wants to generate a survey to do
+	 * ACS (automatic channel selection).
+	 * Force a non-fragmented scan in that case.
+	 */
+	if (vif && ieee80211_vif_type_p2p(vif) == NL80211_IFTYPE_AP)
+		return IWL_SCAN_TYPE_WILD;
+
 	ieee80211_iterate_active_interfaces_atomic(mvm->hw,
 						   IEEE80211_IFACE_ITER_NORMAL,
 						   iwl_mvm_scan_iterator,
@@ -852,11 +860,13 @@ static inline bool iwl_mvm_scan_use_ebs(struct iwl_mvm *mvm,
 	 *	4. it's not a p2p find operation.
 	 *	5. we are not in low latency mode,
 	 *	   or if fragmented ebs is supported by the FW
+	 *	6. the VIF is not an AP interface (scan wants survey results)
 	 */
 	return ((capa->flags & IWL_UCODE_TLV_FLAGS_EBS_SUPPORT) &&
 		mvm->last_ebs_successful && IWL_MVM_ENABLE_EBS &&
 		vif->type != NL80211_IFTYPE_P2P_DEVICE &&
-		(!low_latency || iwl_mvm_is_frag_ebs_supported(mvm)));
+		(!low_latency || iwl_mvm_is_frag_ebs_supported(mvm)) &&
+		ieee80211_vif_type_p2p(vif) != NL80211_IFTYPE_AP);
 }
 
 static inline bool iwl_mvm_is_regular_scan(struct iwl_mvm_scan_params *params)
@@ -2124,7 +2134,8 @@ static u16 iwl_mvm_scan_umac_flags_v2(struct iwl_mvm *mvm,
 
 static u8 iwl_mvm_scan_umac_flags2(struct iwl_mvm *mvm,
 				   struct iwl_mvm_scan_params *params,
-				   struct ieee80211_vif *vif, int type)
+				   struct ieee80211_vif *vif, int type,
+				   u16 gen_flags)
 {
 	u8 flags = 0;
 
@@ -2144,6 +2155,13 @@ static u8 iwl_mvm_scan_umac_flags2(struct iwl_mvm *mvm,
 			IWL_UCODE_TLV_CAPA_SCAN_DONT_TOGGLE_ANT))
 		flags |= IWL_UMAC_SCAN_GEN_PARAMS_FLAGS2_DONT_TOGGLE_ANT;
 
+	/* Passive and AP interface -> ACS (automatic channel selection) */
+	if (gen_flags & IWL_UMAC_SCAN_GEN_FLAGS_V2_FORCE_PASSIVE &&
+	    ieee80211_vif_type_p2p(vif) == NL80211_IFTYPE_AP &&
+	    iwl_fw_lookup_notif_ver(mvm->fw, SCAN_GROUP, CHANNEL_SURVEY_NOTIF,
+				    0) >= 1)
+		flags |= IWL_UMAC_SCAN_GEN_FLAGS2_COLLECT_CHANNEL_STATS;
+
 	return flags;
 }
 
@@ -2513,7 +2531,8 @@ static int iwl_mvm_scan_umac_v14_and_above(struct iwl_mvm *mvm,
 	gen_flags = iwl_mvm_scan_umac_flags_v2(mvm, params, vif, type);
 
 	if (version >= 15)
-		gen_flags2 = iwl_mvm_scan_umac_flags2(mvm, params, vif, type);
+		gen_flags2 = iwl_mvm_scan_umac_flags2(mvm, params, vif, type,
+						      gen_flags);
 	else
 		gen_flags2 = 0;
 
@@ -3602,3 +3621,194 @@ int iwl_mvm_int_mlo_scan(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 
 	return iwl_mvm_int_mlo_scan_start(mvm, vif, channels, n_channels);
 }
+
+static int iwl_mvm_chanidx_from_phy(struct iwl_mvm *mvm,
+				    enum nl80211_band band,
+				    u16 phy_chan_num)
+{
+	struct ieee80211_supported_band *sband = mvm->hw->wiphy->bands[band];
+	int chan_idx;
+
+	if (WARN_ON_ONCE(!sband))
+		return -EINVAL;
+
+	for (chan_idx = 0; chan_idx < sband->n_channels; chan_idx++) {
+		struct ieee80211_channel *channel = &sband->channels[chan_idx];
+
+		if (channel->hw_value == phy_chan_num)
+			return chan_idx;
+	}
+
+	return -EINVAL;
+}
+
+static u32 iwl_mvm_div_by_db(u32 value, u8 db)
+{
+	/*
+	 * 2^32 * 10**(i / 10) for i = [1, 10], skipping 0 and simply stopping
+	 * at 10 dB and looping instead of using a much larger table.
+	 *
+	 * Using 64 bit math is overkill, but means the helper does not require
+	 * a limit on the input range.
+	 */
+	static const u32 db_to_val[] = {
+		0xcb59185e, 0xa1866ba8, 0x804dce7a, 0x65ea59fe, 0x50f44d89,
+		0x404de61f, 0x331426af, 0x2892c18b, 0x203a7e5b, 0x1999999a,
+	};
+
+	while (value && db > 0) {
+		u8 change = min_t(u8, db, ARRAY_SIZE(db_to_val));
+
+		value = (((u64)value) * db_to_val[change - 1]) >> 32;
+
+		db -= change;
+	}
+
+	return value;
+}
+
+VISIBLE_IF_IWLWIFI_KUNIT s8
+iwl_mvm_average_dbm_values(const struct iwl_umac_scan_channel_survey_notif *notif)
+{
+	s8 average_magnitude;
+	u32 average_factor;
+	s8 sum_magnitude = -128;
+	u32 sum_factor = 0;
+	int i, count = 0;
+
+	/*
+	 * To properly average the decibel values (signal values given in dBm)
+	 * we need to do the math in linear space.  Doing a linear average of
+	 * dB (dBm) values is a bit annoying though due to the large range of
+	 * at least -10 to -110 dBm that will not fit into a 32 bit integer.
+	 *
+	 * A 64 bit integer should be sufficient, but then we still have the
+	 * problem that there are no directly usable utility functions
+	 * available.
+	 *
+	 * So, lets not deal with that and instead do much of the calculation
+	 * with a 16.16 fixed point integer along with a base in dBm. 16.16 bit
+	 * gives us plenty of head-room for adding up a few values and even
+	 * doing some math on it. And the tail should be accurate enough too
+	 * (1/2^16 is somewhere around -48 dB, so effectively zero).
+	 *
+	 * i.e. the real value of sum is:
+	 *      sum = sum_factor / 2^16 * 10^(sum_magnitude / 10) mW
+	 *
+	 * However, that does mean we need to be able to bring two values to
+	 * a common base, so we need a helper for that.
+	 *
+	 * Note that this function takes an input with unsigned negative dBm
+	 * values but returns a signed dBm (i.e. a negative value).
+	 */
+
+	for (i = 0; i < ARRAY_SIZE(notif->noise); i++) {
+		s8 val_magnitude;
+		u32 val_factor;
+
+		if (notif->noise[i] == 0xff)
+			continue;
+
+		val_factor = 0x10000;
+		val_magnitude = -notif->noise[i];
+
+		if (val_magnitude <= sum_magnitude) {
+			u8 div_db = sum_magnitude - val_magnitude;
+
+			val_factor = iwl_mvm_div_by_db(val_factor, div_db);
+			val_magnitude = sum_magnitude;
+		} else {
+			u8 div_db = val_magnitude - sum_magnitude;
+
+			sum_factor = iwl_mvm_div_by_db(sum_factor, div_db);
+			sum_magnitude = val_magnitude;
+		}
+
+		sum_factor += val_factor;
+		count++;
+	}
+
+	/* No valid noise measurement, return a very high noise level */
+	if (count == 0)
+		return 0;
+
+	average_magnitude = sum_magnitude;
+	average_factor = sum_factor / count;
+
+	/*
+	 * average_factor will be a number smaller than 1.0 (0x10000) at this
+	 * point. What we need to do now is to adjust average_magnitude so that
+	 * average_factor is between -0.5 dB and 0.5 dB.
+	 *
+	 * Just do -1 dB steps and find the point where
+	 *   -0.5 dB * -i dB = 0x10000 * 10^(-0.5/10) / i dB
+	 *                   = div_by_db(0xe429, i)
+	 * is smaller than average_factor.
+	 */
+	for (i = 0; average_factor < iwl_mvm_div_by_db(0xe429, i); i++) {
+		/* nothing */
+	}
+
+	return average_magnitude - i;
+}
+EXPORT_SYMBOL_IF_IWLWIFI_KUNIT(iwl_mvm_average_dbm_values);
+
+void iwl_mvm_rx_channel_survey_notif(struct iwl_mvm *mvm,
+				     struct iwl_rx_cmd_buffer *rxb)
+{
+	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	const struct iwl_umac_scan_channel_survey_notif *notif =
+		(void *)pkt->data;
+	struct iwl_mvm_acs_survey_channel *info;
+	enum nl80211_band band;
+	int chan_idx;
+
+	lockdep_assert_held(&mvm->mutex);
+
+	if (!mvm->acs_survey) {
+		size_t n_channels = 0;
+
+		for (band = 0; band < NUM_NL80211_BANDS; band++) {
+			if (!mvm->hw->wiphy->bands[band])
+				continue;
+
+			n_channels += mvm->hw->wiphy->bands[band]->n_channels;
+		}
+
+		mvm->acs_survey = kzalloc(struct_size(mvm->acs_survey,
+						      channels, n_channels),
+					  GFP_KERNEL);
+
+		if (!mvm->acs_survey)
+			return;
+
+		mvm->acs_survey->n_channels = n_channels;
+		n_channels = 0;
+		for (band = 0; band < NUM_NL80211_BANDS; band++) {
+			if (!mvm->hw->wiphy->bands[band])
+				continue;
+
+			mvm->acs_survey->bands[band] =
+				&mvm->acs_survey->channels[n_channels];
+			n_channels += mvm->hw->wiphy->bands[band]->n_channels;
+		}
+	}
+
+	band = iwl_mvm_nl80211_band_from_phy(le32_to_cpu(notif->band));
+	chan_idx = iwl_mvm_chanidx_from_phy(mvm, band,
+					    le32_to_cpu(notif->channel));
+	if (WARN_ON_ONCE(chan_idx < 0))
+		return;
+
+	IWL_DEBUG_SCAN(mvm, "channel survey received for freq %d\n",
+		       mvm->hw->wiphy->bands[band]->channels[chan_idx].center_freq);
+
+	info = &mvm->acs_survey->bands[band][chan_idx];
+
+	/* Times are all in ms */
+	info->time = le32_to_cpu(notif->active_time);
+	info->time_busy = le32_to_cpu(notif->busy_time);
+	info->time_rx = le32_to_cpu(notif->rx_time);
+	info->time_tx = le32_to_cpu(notif->tx_time);
+	info->noise = iwl_mvm_average_dbm_values(notif);
+}
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tests/Makefile b/drivers/net/wireless/intel/iwlwifi/mvm/tests/Makefile
index b13aebbf7d5e..6bd56a28cffd 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tests/Makefile
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tests/Makefile
@@ -1,3 +1,3 @@
-iwlmvm-tests-y += module.o links.o
+iwlmvm-tests-y += module.o links.o scan.o
 
 obj-$(CONFIG_IWLWIFI_KUNIT_TESTS) += iwlmvm-tests.o
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tests/scan.c b/drivers/net/wireless/intel/iwlwifi/mvm/tests/scan.c
new file mode 100644
index 000000000000..d3b6a57c3ebe
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tests/scan.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KUnit tests for channel helper functions
+ *
+ * Copyright (C) 2024 Intel Corporation
+ */
+#include <net/mac80211.h>
+#include "../mvm.h"
+#include <kunit/test.h>
+
+MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING);
+
+static const struct acs_average_db_case {
+	const char *desc;
+	u8 neg_dbm[22];
+	s8 result;
+} acs_average_db_cases[] = {
+	{
+		.desc = "Smallest possible value, all filled",
+		.neg_dbm = {
+			128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+			128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+			128, 128
+		},
+		.result = -128,
+	},
+	{
+		.desc = "Biggest possible value, all filled",
+		.neg_dbm = {
+			0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+			0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+			0, 0,
+		},
+		.result = 0,
+	},
+	{
+		.desc = "Smallest possible value, partial filled",
+		.neg_dbm = {
+			128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+			0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff,
+		},
+		.result = -128,
+	},
+	{
+		.desc = "Biggest possible value, partial filled",
+		.neg_dbm = {
+			0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+			0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff,
+		},
+		.result = 0,
+	},
+	{
+		.desc = "Adding -80dBm to -75dBm until it is still rounded to -79dBm",
+		.neg_dbm = {
+			75, 80, 80, 80, 80, 80, 80, 80, 80, 80,
+			80, 80, 80, 80, 80, 80, 80, 0xff, 0xff, 0xff,
+			0xff, 0xff,
+		},
+		.result = -79,
+	},
+	{
+		.desc = "Adding -80dBm to -75dBm until it is just rounded to -80dBm",
+		.neg_dbm = {
+			75, 80, 80, 80, 80, 80, 80, 80, 80, 80,
+			80, 80, 80, 80, 80, 80, 80, 80, 0xff, 0xff,
+			0xff, 0xff,
+		},
+		.result = -80,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(acs_average_db, acs_average_db_cases, desc)
+
+static void test_acs_average_db(struct kunit *test)
+{
+	const struct acs_average_db_case *params = test->param_value;
+	struct iwl_umac_scan_channel_survey_notif notif;
+	int i;
+
+	/* Test the values in the given order */
+	for (i = 0; i < ARRAY_SIZE(params->neg_dbm); i++)
+		notif.noise[i] = params->neg_dbm[i];
+	KUNIT_ASSERT_EQ(test,
+			iwl_mvm_average_dbm_values(&notif),
+			params->result);
+
+	/* Test in reverse order */
+	for (i = 0; i < ARRAY_SIZE(params->neg_dbm); i++)
+		notif.noise[ARRAY_SIZE(params->neg_dbm) - i - 1] =
+			params->neg_dbm[i];
+	KUNIT_ASSERT_EQ(test,
+			iwl_mvm_average_dbm_values(&notif),
+			params->result);
+}
+
+static struct kunit_case acs_average_db_case[] = {
+	KUNIT_CASE_PARAM(test_acs_average_db, acs_average_db_gen_params),
+	{}
+};
+
+static struct kunit_suite acs_average_db = {
+	.name = "iwlmvm-acs-average-db",
+	.test_cases = acs_average_db_case,
+};
+
+kunit_test_suite(acs_average_db);