wifi: iwlwifi: mvm: record and return channel survey information

While doing a passive scan, the firmware will report per-channel survey
information. This information is primarily useful for hostapd when doing
an ACS (Automatic Channel Selection). Collect this information and add
it to the result set when getting the survey information.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240506095953.9287591a5999.I54a3f9f6480d3694e67eea1cb4f5853beace2780@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 111 insertions, 1 deletions

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);