7 files changed, 416 insertions, 1 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/Makefile b/drivers/net/wireless/intel/iwlwifi/mvm/Makefile
index 593fe28d89cf..5c754b87ea20 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/Makefile
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_IWLMVM)   += iwlmvm.o
+obj-$(CONFIG_IWLWIFI_KUNIT_TESTS) += tests/
 iwlmvm-y += fw.o mac80211.o nvm.o ops.o phy-ctxt.o mac-ctxt.o
 iwlmvm-y += utils.o rx.o rxmq.o tx.o binding.o quota.o sta.o sf.o
 iwlmvm-y += scan.o time-event.o rs.o rs-fw.o
@@ -15,4 +16,4 @@ iwlmvm-$(CONFIG_IWLWIFI_LEDS) += led.o
 iwlmvm-$(CONFIG_PM) += d3.o
 iwlmvm-$(CONFIG_IWLMEI) += vendor-cmd.o
 
-ccflags-y += -I $(srctree)/$(src)/../
+subdir-ccflags-y += -I $(srctree)/$(src)/../
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/link.c b/drivers/net/wireless/intel/iwlwifi/mvm/link.c
index 9f69e04594e4..23660238348b 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/link.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/link.c
@@ -329,3 +329,175 @@ int iwl_mvm_disable_link(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 
 	return ret;
 }
+
+struct iwl_mvm_rssi_to_grade {
+	s8 rssi[2];
+	u16 grade;
+};
+
+#define RSSI_TO_GRADE_LINE(_lb, _hb_uhb, _grade) \
+	{ \
+		.rssi = {_lb, _hb_uhb}, \
+		.grade = _grade \
+	}
+
+/*
+ * This array must be sorted by increasing RSSI for proper functionality.
+ * The grades are actually estimated throughput, represented as fixed-point
+ * with a scale factor of 1/10.
+ */
+static const struct iwl_mvm_rssi_to_grade rssi_to_grade_map[] = {
+	RSSI_TO_GRADE_LINE(-85, -89, 177),
+	RSSI_TO_GRADE_LINE(-83, -86, 344),
+	RSSI_TO_GRADE_LINE(-82, -85, 516),
+	RSSI_TO_GRADE_LINE(-80, -83, 688),
+	RSSI_TO_GRADE_LINE(-77, -79, 1032),
+	RSSI_TO_GRADE_LINE(-73, -76, 1376),
+	RSSI_TO_GRADE_LINE(-70, -74, 1548),
+	RSSI_TO_GRADE_LINE(-69, -72, 1750),
+	RSSI_TO_GRADE_LINE(-65, -68, 2064),
+	RSSI_TO_GRADE_LINE(-61, -66, 2294),
+	RSSI_TO_GRADE_LINE(-58, -61, 2580),
+	RSSI_TO_GRADE_LINE(-55, -58, 2868),
+	RSSI_TO_GRADE_LINE(-46, -55, 3098),
+	RSSI_TO_GRADE_LINE(-43, -54, 3442)
+};
+
+#define MAX_GRADE (rssi_to_grade_map[ARRAY_SIZE(rssi_to_grade_map) - 1].grade)
+
+#define DEFAULT_CHAN_LOAD_LB	30
+#define DEFAULT_CHAN_LOAD_HB	15
+#define DEFAULT_CHAN_LOAD_UHB	0
+
+/* Factors calculation is done with fixed-point with a scaling factor of 1/256 */
+#define SCALE_FACTOR 256
+
+/* Convert a percentage from [0,100] to [0,255] */
+#define NORMALIZE_PERCENT_TO_255(percentage) ((percentage) * SCALE_FACTOR / 100)
+
+static unsigned int
+iwl_mvm_get_puncturing_factor(const struct ieee80211_bss_conf *link_conf)
+{
+	enum nl80211_chan_width chan_width =
+		link_conf->chanreq.oper.width;
+	int mhz = nl80211_chan_width_to_mhz(chan_width);
+	unsigned int n_subchannels, n_punctured, puncturing_penalty;
+
+	if (WARN_ONCE(mhz < 20 || mhz > 320,
+		      "Invalid channel width : (%d)\n", mhz))
+		return SCALE_FACTOR;
+
+	/* No puncturing, no penalty */
+	if (mhz < 80)
+		return SCALE_FACTOR;
+
+	/* total number of subchannels */
+	n_subchannels = mhz / 20;
+	/* how many of these are punctured */
+	n_punctured = hweight16(link_conf->chanreq.oper.punctured);
+
+	puncturing_penalty = n_punctured * SCALE_FACTOR / n_subchannels;
+	return SCALE_FACTOR - puncturing_penalty;
+}
+
+static unsigned int
+iwl_mvm_get_chan_load_factor(struct ieee80211_bss_conf *link_conf)
+{
+	struct iwl_mvm_vif_link_info *mvm_link =
+		iwl_mvm_vif_from_mac80211(link_conf->vif)->link[link_conf->link_id];
+	const struct element *bss_load_elem =
+		ieee80211_bss_get_elem(link_conf->bss, WLAN_EID_QBSS_LOAD);
+	const struct ieee80211_bss_load_elem *bss_load;
+	enum nl80211_band band = link_conf->chanreq.oper.chan->band;
+	unsigned int chan_load;
+	u32 chan_load_by_us;
+
+	/* If there isn't BSS Load element, take the defaults */
+	if (!bss_load_elem ||
+	    bss_load_elem->datalen != sizeof(*bss_load)) {
+		switch (band) {
+		case NL80211_BAND_2GHZ:
+			chan_load = DEFAULT_CHAN_LOAD_LB;
+			break;
+		case NL80211_BAND_5GHZ:
+			chan_load = DEFAULT_CHAN_LOAD_HB;
+			break;
+		case NL80211_BAND_6GHZ:
+			chan_load = DEFAULT_CHAN_LOAD_UHB;
+			break;
+		default:
+			chan_load = 0;
+			break;
+		}
+		/* The defaults are given in percentage */
+		return SCALE_FACTOR - NORMALIZE_PERCENT_TO_255(chan_load);
+	}
+
+	bss_load = (const void *)bss_load_elem->data;
+	/* Channel util is in range 0-255 */
+	chan_load = bss_load->channel_util;
+
+	if (!mvm_link || !mvm_link->active)
+		goto done;
+
+	if (WARN_ONCE(!mvm_link->phy_ctxt,
+		      "Active link (%u) without phy ctxt assigned!\n",
+		      link_conf->link_id))
+		goto done;
+
+	/* channel load by us is given in percentage */
+	chan_load_by_us =
+		NORMALIZE_PERCENT_TO_255(mvm_link->phy_ctxt->channel_load_by_us);
+
+	/* Use only values that firmware sends that can possibly be valid */
+	if (chan_load_by_us <= chan_load)
+		chan_load -= chan_load_by_us;
+done:
+	return  SCALE_FACTOR - chan_load;
+}
+
+/* This function calculates the grade of a link. Returns 0 in error case */
+unsigned int iwl_mvm_get_link_grade(struct ieee80211_bss_conf *link_conf)
+{
+	enum nl80211_band band;
+	int i, rssi_idx;
+	s32 link_rssi;
+	unsigned int grade = MAX_GRADE;
+
+	if (WARN_ON_ONCE(!link_conf))
+		return 0;
+
+	band = link_conf->chanreq.oper.chan->band;
+	if (WARN_ONCE(band != NL80211_BAND_2GHZ &&
+		      band != NL80211_BAND_5GHZ &&
+		      band != NL80211_BAND_6GHZ,
+		      "Invalid band (%u)\n", band))
+		return 0;
+
+	link_rssi = MBM_TO_DBM(link_conf->bss->signal);
+	/*
+	 * For 6 GHz the RSSI of the beacons is lower than
+	 * the RSSI of the data.
+	 */
+	if (band == NL80211_BAND_6GHZ)
+		link_rssi += 4;
+
+	rssi_idx = band == NL80211_BAND_2GHZ ? 0 : 1;
+
+	/* Get grade based on RSSI */
+	for (i = 0; i < ARRAY_SIZE(rssi_to_grade_map); i++) {
+		const struct iwl_mvm_rssi_to_grade *line =
+			&rssi_to_grade_map[i];
+
+		if (link_rssi > line->rssi[rssi_idx])
+			continue;
+		grade = line->grade;
+		break;
+	}
+
+	/* apply the channel load and puncturing factors */
+	grade = grade * iwl_mvm_get_chan_load_factor(link_conf) / SCALE_FACTOR;
+	grade = grade * iwl_mvm_get_puncturing_factor(link_conf) / SCALE_FACTOR;
+	return grade;
+}
+EXPORT_SYMBOL_IF_IWLWIFI_KUNIT(iwl_mvm_get_link_grade);
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index 0dd83e0171ba..c477978d8fa3 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -2449,6 +2449,7 @@ u32 iwl_mvm_get_sec_flags(struct iwl_mvm *mvm,
 			  struct ieee80211_vif *vif,
 			  struct ieee80211_sta *sta,
 			  struct ieee80211_key_conf *keyconf);
+unsigned int iwl_mvm_get_link_grade(struct ieee80211_bss_conf *link_conf);
 
 bool iwl_rfi_supported(struct iwl_mvm *mvm);
 int iwl_rfi_send_config_cmd(struct iwl_mvm *mvm,
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tests/Makefile b/drivers/net/wireless/intel/iwlwifi/mvm/tests/Makefile
new file mode 100644
index 000000000000..b13aebbf7d5e
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tests/Makefile
@@ -0,0 +1,3 @@
+iwlmvm-tests-y += module.o links.o
+
+obj-$(CONFIG_IWLWIFI_KUNIT_TESTS) += iwlmvm-tests.o
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tests/links.c b/drivers/net/wireless/intel/iwlwifi/mvm/tests/links.c
new file mode 100644
index 000000000000..321d18de1ca3
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tests/links.c
@@ -0,0 +1,210 @@
+// 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 struct ieee80211_channel chan_5ghz = {
+	.band = NL80211_BAND_5GHZ,
+};
+
+static struct ieee80211_channel chan_6ghz = {
+	.band = NL80211_BAND_6GHZ,
+};
+
+static struct ieee80211_channel chan_2ghz = {
+	.band = NL80211_BAND_2GHZ,
+};
+
+static struct iwl_mvm_phy_ctxt ctx = {};
+
+static struct iwl_mvm_vif_link_info mvm_link = {
+	.phy_ctxt = &ctx,
+	.active = true
+};
+
+static struct cfg80211_bss bss = {};
+
+static struct ieee80211_bss_conf link_conf = {.bss = &bss};
+
+static const struct link_grading_case {
+	const char *desc;
+	const struct cfg80211_chan_def chandef;
+	s32 signal;
+	s16 channel_util;
+	int chan_load_by_us;
+	unsigned int grade;
+} link_grading_cases[] = {
+	{
+		.desc = "UHB, RSSI below range, no factors",
+		.chandef = {
+			.chan = &chan_6ghz,
+			.width = NL80211_CHAN_WIDTH_20,
+		},
+		.signal = -100,
+		.grade = 177,
+	},
+	{
+		.desc = "LB, RSSI in range, no factors",
+		.chandef = {
+			.chan = &chan_2ghz,
+			.width = NL80211_CHAN_WIDTH_20,
+		},
+		.signal = -84,
+		.grade = 344,
+	},
+	{
+		.desc = "HB, RSSI above range, no factors",
+		.chandef = {
+			.chan = &chan_5ghz,
+			.width = NL80211_CHAN_WIDTH_20,
+		},
+		.signal = -50,
+		.grade = 3442,
+	},
+	{
+		.desc = "HB, BSS Load IE (20 percent), inactive link, no puncturing factor",
+		.chandef = {
+			.chan = &chan_5ghz,
+			.width = NL80211_CHAN_WIDTH_20,
+		},
+		.signal = -66,
+		.channel_util = 51,
+		.grade = 1836,
+	},
+	{
+		.desc = "LB, BSS Load IE (20 percent), active link, chan_load_by_us=10 percent. No puncturing factor",
+		.chandef = {
+			.chan = &chan_2ghz,
+			.width = NL80211_CHAN_WIDTH_20,
+		},
+		.signal = -61,
+		.channel_util = 51,
+		.chan_load_by_us = 10,
+		.grade = 2061,
+	},
+	{
+		.desc = "UHB, BSS Load IE (40 percent), active link, chan_load_by_us=50 (invalid) percent. No puncturing factor",
+		.chandef = {
+			.chan = &chan_6ghz,
+			.width = NL80211_CHAN_WIDTH_20,
+		},
+		.signal = -66,
+		.channel_util = 102,
+		.chan_load_by_us = 50,
+		.grade = 1552,
+	},
+	{	.desc = "HB, 80 MHz, no channel load factor, punctured percentage 0",
+		.chandef = {
+			.chan = &chan_5ghz,
+			.width = NL80211_CHAN_WIDTH_80,
+			.punctured = 0x0000
+		},
+		.signal = -72,
+		.grade = 1750,
+	},
+	{	.desc = "HB, 160 MHz, no channel load factor, punctured percentage 25",
+		.chandef = {
+			.chan = &chan_5ghz,
+			.width = NL80211_CHAN_WIDTH_160,
+			.punctured = 0x3
+		},
+		.signal = -72,
+		.grade = 1312,
+	},
+	{	.desc = "UHB, 320 MHz, no channel load factor, punctured percentage 12.5 (2/16)",
+		.chandef = {
+			.chan = &chan_6ghz,
+			.width = NL80211_CHAN_WIDTH_320,
+			.punctured = 0x3
+		},
+		.signal = -72,
+		.grade = 1806,
+	},
+	{	.desc = "HB, 160 MHz, channel load 20, channel load by us 10, punctured percentage 25",
+		.chandef = {
+			.chan = &chan_5ghz,
+			.width = NL80211_CHAN_WIDTH_160,
+			.punctured = 0x3
+		},
+		.channel_util = 51,
+		.chan_load_by_us = 10,
+		.signal = -72,
+		.grade = 1179,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(link_grading, link_grading_cases, desc)
+
+static void setup_link_conf(struct kunit *test)
+{
+	const struct link_grading_case *params = test->param_value;
+	size_t vif_size = sizeof(struct ieee80211_vif) +
+		sizeof(struct iwl_mvm_vif);
+	struct ieee80211_vif *vif = kunit_kzalloc(test, vif_size, GFP_KERNEL);
+	struct ieee80211_bss_load_elem *bss_load;
+	struct element *element;
+	size_t ies_size = sizeof(struct cfg80211_bss_ies) + sizeof(*bss_load) + sizeof(element);
+	struct cfg80211_bss_ies *ies;
+	struct iwl_mvm_vif *mvmvif;
+
+	KUNIT_ASSERT_NOT_NULL(test, vif);
+
+	mvmvif = iwl_mvm_vif_from_mac80211(vif);
+	if (params->chan_load_by_us > 0) {
+		ctx.channel_load_by_us = params->chan_load_by_us;
+		mvmvif->link[0] = &mvm_link;
+	}
+
+	link_conf.vif = vif;
+	link_conf.chanreq.oper = params->chandef;
+	bss.signal = DBM_TO_MBM(params->signal);
+
+	ies = kunit_kzalloc(test, ies_size, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, ies);
+	ies->len = sizeof(*bss_load) + sizeof(struct element);
+
+	element = (void *)ies->data;
+	element->datalen = sizeof(*bss_load);
+	element->id = 11;
+
+	bss_load = (void *)element->data;
+	bss_load->channel_util = params->channel_util;
+
+	rcu_assign_pointer(bss.ies, ies);
+}
+
+static void test_link_grading(struct kunit *test)
+{
+	const struct link_grading_case *params = test->param_value;
+	unsigned int ret;
+
+	setup_link_conf(test);
+
+	rcu_read_lock();
+	ret = iwl_mvm_get_link_grade(&link_conf);
+	rcu_read_unlock();
+
+	KUNIT_EXPECT_EQ(test, ret, params->grade);
+
+	kunit_kfree(test, link_conf.vif);
+	RCU_INIT_POINTER(bss.ies, NULL);
+}
+
+static struct kunit_case link_grading_test_cases[] = {
+	KUNIT_CASE_PARAM(test_link_grading, link_grading_gen_params),
+	{}
+};
+
+static struct kunit_suite link_grading = {
+	.name = "iwlmvm-link-grading",
+	.test_cases = link_grading_test_cases,
+};
+
+kunit_test_suite(link_grading);
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tests/module.c b/drivers/net/wireless/intel/iwlwifi/mvm/tests/module.c
new file mode 100644
index 000000000000..f556acbac77f
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tests/module.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This is just module boilerplate for the iwlmvm kunit module.
+ *
+ * Copyright (C) 2024 Intel Corporation
+ */
+#include <linux/module.h>
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("kunit tests for iwlmvm");
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 7f9b829dcb1e..de2dce743ee2 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1287,6 +1287,24 @@ struct ieee80211_ttlm_elem {
 	u8 optional[];
 } __packed;
 
+/**
+ * struct ieee80211_bss_load_elem - BSS Load elemen
+ *
+ * Defined in section 9.4.2.26 in IEEE 802.11-REVme D4.1
+ *
+ * @sta_count: total number of STAs currently associated with the AP.
+ * @channel_util: Percentage of time that the access point sensed the channel
+ *	was busy. This value is in range [0, 255], the highest value means
+ *	100% busy.
+ * @avail_admission_capa: remaining amount of medium time used for admission
+ *	control.
+ */
+struct ieee80211_bss_load_elem {
+	__le16 sta_count;
+	u8 channel_util;
+	__le16 avail_admission_capa;
+} __packed;
+
 struct ieee80211_mgmt {
 	__le16 frame_control;
 	__le16 duration;