1 files changed, 339 insertions, 0 deletions
diff --git a/sys/contrib/dev/iwlwifi/mld/tests/link-selection.c b/sys/contrib/dev/iwlwifi/mld/tests/link-selection.c
new file mode 100644
index 000000000000..766c24db3613
--- /dev/null
+++ b/sys/contrib/dev/iwlwifi/mld/tests/link-selection.c
@@ -0,0 +1,339 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * KUnit tests for link selection functions
+ *
+ * Copyright (C) 2025 Intel Corporation
+ */
+#include <kunit/static_stub.h>
+
+#include "utils.h"
+#include "mld.h"
+#include "link.h"
+#include "iface.h"
+#include "phy.h"
+#include "mlo.h"
+
+static const struct link_grading_test_case {
+	const char *desc;
+	struct {
+		struct {
+			u8 link_id;
+			const struct cfg80211_chan_def *chandef;
+			bool active;
+			s32 signal;
+			bool has_chan_util_elem;
+			u8 chan_util; /* 0-255 , used only if has_chan_util_elem is true */
+			u8 chan_load_by_us; /* 0-100, used only if active is true */;
+		} link;
+	} input;
+	unsigned int expected_grade;
+} link_grading_cases[] = {
+	{
+		.desc = "channel util of 128 (50%)",
+		.input.link = {
+			.link_id = 0,
+			.chandef = &chandef_2ghz_20mhz,
+			.active = false,
+			.has_chan_util_elem = true,
+			.chan_util = 128,
+		},
+		.expected_grade = 86,
+	},
+	{
+		.desc = "channel util of 180 (70%)",
+		.input.link = {
+			.link_id = 0,
+			.chandef = &chandef_2ghz_20mhz,
+			.active = false,
+			.has_chan_util_elem = true,
+			.chan_util = 180,
+		},
+		.expected_grade = 51,
+	},
+	{
+		.desc = "channel util of 180 (70%), channel load by us of 10%",
+		.input.link = {
+			.link_id = 0,
+			.chandef = &chandef_2ghz_20mhz,
+			.has_chan_util_elem = true,
+			.chan_util = 180,
+			.active = true,
+			.chan_load_by_us = 10,
+		},
+		.expected_grade = 67,
+	},
+		{
+		.desc = "no channel util element",
+		.input.link = {
+			.link_id = 0,
+			.chandef = &chandef_2ghz_20mhz,
+			.active = true,
+		},
+		.expected_grade = 120,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(link_grading, link_grading_cases, desc);
+
+static void setup_link(struct ieee80211_bss_conf *link)
+{
+	struct kunit *test = kunit_get_current_test();
+	struct iwl_mld *mld = test->priv;
+	const struct link_grading_test_case *test_param =
+		(const void *)(test->param_value);
+
+	KUNIT_ALLOC_AND_ASSERT(test, link->bss);
+
+	link->bss->signal = DBM_TO_MBM(test_param->input.link.signal);
+
+	link->chanreq.oper = *test_param->input.link.chandef;
+
+	if (test_param->input.link.has_chan_util_elem) {
+		struct cfg80211_bss_ies *ies;
+		struct ieee80211_bss_load_elem bss_load = {
+			.channel_util = test_param->input.link.chan_util,
+		};
+		struct element *elem =
+			iwlmld_kunit_gen_element(WLAN_EID_QBSS_LOAD,
+						 &bss_load,
+						 sizeof(bss_load));
+		unsigned int elem_len = sizeof(*elem) + sizeof(bss_load);
+
+		KUNIT_ALLOC_AND_ASSERT_SIZE(test, ies, sizeof(*ies) + elem_len);
+		memcpy(ies->data, elem, elem_len);
+		ies->len = elem_len;
+		rcu_assign_pointer(link->bss->beacon_ies, ies);
+		rcu_assign_pointer(link->bss->ies, ies);
+	}
+
+	if (test_param->input.link.active) {
+		struct ieee80211_chanctx_conf *chan_ctx =
+			wiphy_dereference(mld->wiphy, link->chanctx_conf);
+		struct iwl_mld_phy *phy;
+
+		KUNIT_ASSERT_NOT_NULL(test, chan_ctx);
+
+		phy = iwl_mld_phy_from_mac80211(chan_ctx);
+
+		phy->channel_load_by_us = test_param->input.link.chan_load_by_us;
+	}
+}
+
+static void test_link_grading(struct kunit *test)
+{
+	struct iwl_mld *mld = test->priv;
+	const struct link_grading_test_case *test_param =
+		(const void *)(test->param_value);
+	struct ieee80211_vif *vif;
+	struct ieee80211_bss_conf *link;
+	unsigned int actual_grade;
+	/* Extract test case parameters */
+	u8 link_id = test_param->input.link.link_id;
+	bool active = test_param->input.link.active;
+	u16 valid_links;
+	struct iwl_mld_kunit_link assoc_link = {
+		.chandef = test_param->input.link.chandef,
+	};
+
+	/* If the link is not active, use a different link as the assoc link */
+	if (active) {
+		assoc_link.id = link_id;
+		valid_links = BIT(link_id);
+	} else {
+		assoc_link.id = BIT(ffz(BIT(link_id)));
+		valid_links = BIT(assoc_link.id) | BIT(link_id);
+	}
+
+	vif = iwlmld_kunit_setup_mlo_assoc(valid_links, &assoc_link);
+
+	wiphy_lock(mld->wiphy);
+	link = wiphy_dereference(mld->wiphy, vif->link_conf[link_id]);
+	KUNIT_ASSERT_NOT_NULL(test, link);
+
+	setup_link(link);
+
+	actual_grade = iwl_mld_get_link_grade(mld, link);
+	wiphy_unlock(mld->wiphy);
+
+	/* Assert that the returned grade matches the expected grade */
+	KUNIT_EXPECT_EQ(test, actual_grade, test_param->expected_grade);
+}
+
+static struct kunit_case link_selection_cases[] = {
+	KUNIT_CASE_PARAM(test_link_grading, link_grading_gen_params),
+	{},
+};
+
+static struct kunit_suite link_selection = {
+	.name = "iwlmld-link-selection-tests",
+	.test_cases = link_selection_cases,
+	.init = iwlmld_kunit_test_init,
+};
+
+kunit_test_suite(link_selection);
+
+static const struct link_pair_case {
+	const char *desc;
+	const struct cfg80211_chan_def *chandef_a, *chandef_b;
+	bool low_latency_vif;
+	u32 chan_load_not_by_us;
+	bool primary_link_active;
+	u32 expected_result;
+} link_pair_cases[] = {
+	{
+		.desc = "Unequal bandwidth, primary link inactive, EMLSR not allowed",
+		.low_latency_vif = false,
+		.primary_link_active = false,
+		.chandef_a = &chandef_5ghz_40mhz,
+		.chandef_b = &chandef_6ghz_20mhz,
+		.expected_result = IWL_MLD_EMLSR_EXIT_CHAN_LOAD,
+	},
+	{
+		.desc = "Equal bandwidths, sufficient channel load, EMLSR allowed",
+		.low_latency_vif = false,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 11,
+		.chandef_a = &chandef_5ghz_40mhz,
+		.chandef_b = &chandef_6ghz_40mhz,
+		.expected_result = 0,
+	},
+	{
+		.desc = "Equal bandwidths, insufficient channel load, EMLSR not allowed",
+		.low_latency_vif = false,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 6,
+		.chandef_a = &chandef_5ghz_80mhz,
+		.chandef_b = &chandef_6ghz_80mhz,
+		.expected_result = IWL_MLD_EMLSR_EXIT_CHAN_LOAD,
+	},
+	{
+		.desc = "Low latency VIF, sufficient channel load, EMLSR allowed",
+		.low_latency_vif = true,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 6,
+		.chandef_a = &chandef_5ghz_160mhz,
+		.chandef_b = &chandef_6ghz_160mhz,
+		.expected_result = 0,
+	},
+	{
+		.desc = "Different bandwidths (2x ratio), primary link load permits EMLSR",
+		.low_latency_vif = false,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 30,
+		.chandef_a = &chandef_5ghz_40mhz,
+		.chandef_b = &chandef_6ghz_20mhz,
+		.expected_result = 0,
+	},
+	{
+		.desc = "Different bandwidths (4x ratio), primary link load permits EMLSR",
+		.low_latency_vif = false,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 45,
+		.chandef_a = &chandef_5ghz_80mhz,
+		.chandef_b = &chandef_6ghz_20mhz,
+		.expected_result = 0,
+	},
+	{
+		.desc = "Different bandwidths (16x ratio), primary link load insufficient",
+		.low_latency_vif = false,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 45,
+		.chandef_a = &chandef_6ghz_320mhz,
+		.chandef_b = &chandef_5ghz_20mhz,
+		.expected_result = IWL_MLD_EMLSR_EXIT_CHAN_LOAD,
+	},
+	{
+		.desc = "Same band not allowed (2.4 GHz)",
+		.low_latency_vif = false,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 30,
+		.chandef_a = &chandef_2ghz_20mhz,
+		.chandef_b = &chandef_2ghz_11_20mhz,
+		.expected_result = IWL_MLD_EMLSR_EXIT_EQUAL_BAND,
+	},
+	{
+		.desc = "Same band not allowed (5 GHz)",
+		.low_latency_vif = false,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 30,
+		.chandef_a = &chandef_5ghz_40mhz,
+		.chandef_b = &chandef_5ghz_40mhz,
+		.expected_result = IWL_MLD_EMLSR_EXIT_EQUAL_BAND,
+	},
+	{
+		.desc = "Same band allowed (5 GHz separated)",
+		.low_latency_vif = false,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 30,
+		.chandef_a = &chandef_5ghz_40mhz,
+		.chandef_b = &chandef_5ghz_120_40mhz,
+		.expected_result = 0,
+	},
+	{
+		.desc = "Same band not allowed (6 GHz)",
+		.low_latency_vif = false,
+		.primary_link_active = true,
+		.chan_load_not_by_us = 30,
+		.chandef_a = &chandef_6ghz_160mhz,
+		.chandef_b = &chandef_6ghz_221_160mhz,
+		.expected_result = IWL_MLD_EMLSR_EXIT_EQUAL_BAND,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(link_pair, link_pair_cases, desc);
+
+static void test_iwl_mld_link_pair_allows_emlsr(struct kunit *test)
+{
+	const struct link_pair_case *params = test->param_value;
+	struct iwl_mld *mld = test->priv;
+	struct ieee80211_vif *vif;
+	/* link A is the primary and link B is the secondary */
+	struct iwl_mld_link_sel_data a = {
+		.chandef = params->chandef_a,
+		.link_id = 4,
+	};
+	struct iwl_mld_link_sel_data b = {
+		.chandef = params->chandef_b,
+		.link_id = 5,
+	};
+	struct iwl_mld_kunit_link assoc_link = {
+		.chandef = params->primary_link_active ? a.chandef : b.chandef,
+		.id = params->primary_link_active ? a.link_id : b.link_id,
+	};
+	u32 result;
+
+	vif = iwlmld_kunit_setup_mlo_assoc(BIT(a.link_id) | BIT(b.link_id),
+					   &assoc_link);
+
+	if (params->low_latency_vif)
+		iwl_mld_vif_from_mac80211(vif)->low_latency_causes = 1;
+
+	wiphy_lock(mld->wiphy);
+
+	/* Simulate channel load */
+	if (params->primary_link_active) {
+		struct iwl_mld_phy *phy =
+			iwlmld_kunit_get_phy_of_link(vif, a.link_id);
+
+		phy->avg_channel_load_not_by_us = params->chan_load_not_by_us;
+	}
+
+	result = iwl_mld_emlsr_pair_state(vif, &a, &b);
+
+	wiphy_unlock(mld->wiphy);
+
+	KUNIT_EXPECT_EQ(test, result, params->expected_result);
+}
+
+static struct kunit_case link_pair_criteria_test_cases[] = {
+	KUNIT_CASE_PARAM(test_iwl_mld_link_pair_allows_emlsr, link_pair_gen_params),
+	{}
+};
+
+static struct kunit_suite link_pair_criteria_tests = {
+	.name = "iwlmld_link_pair_allows_emlsr",
+	.test_cases = link_pair_criteria_test_cases,
+	.init = iwlmld_kunit_test_init,
+};
+
+kunit_test_suite(link_pair_criteria_tests);