wifi: mac80211: Add support for WBRF features

To support the WBRF mechanism, Wifi adapters utilized in the system must
register the frequencies in use (or unregister those frequencies no longer
used) via the dedicated calls. So that, other drivers responding to the
frequencies can take proper actions to mitigate possible interference.
Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Co-developed-by: Evan Quan <quanliangl@hotmail.com>
Signed-off-by: Evan Quan <quanliangl@hotmail.com>
Signed-off-by: Ma Jun <Jun.Ma2@amd.com>
Link: https://msgid.link/20231211100630.2170152-5-Jun.Ma2@amd.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/Makefile

@@ -67,4 +67,6 @@ mac80211-$(CONFIG_MAC80211_RC_MINSTREL) += $(rc80211_minstrel-y)
 
 obj-y += tests/
 
+mac80211-y += wbrf.o
+
 ccflags-y += -DDEBUG

net/mac80211/chan.c

@@ -507,11 +507,16 @@ static void _ieee80211_change_chanctx(struct ieee80211_local *local,
 
 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
 
+	ieee80211_remove_wbrf(local, &ctx->conf.def);
+
 	ctx->conf.def = *chandef;
 
 	/* check if min chanctx also changed */
 	changed = IEEE80211_CHANCTX_CHANGE_WIDTH |
 		  _ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
+
+	ieee80211_add_wbrf(local, &ctx->conf.def);
+
 	drv_change_chanctx(local, ctx, changed);
 
 	if (!local->use_chanctx) {
@@ -667,6 +672,8 @@ static int ieee80211_add_chanctx(struct ieee80211_local *local,
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
+	ieee80211_add_wbrf(local, &ctx->conf.def);
+
 	if (!local->use_chanctx)
 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
 
@@ -746,6 +753,8 @@ static void ieee80211_del_chanctx(struct ieee80211_local *local,
 	}
 
 	ieee80211_recalc_idle(local);
+
+	ieee80211_remove_wbrf(local, &ctx->conf.def);
 }
 
 static void ieee80211_free_chanctx(struct ieee80211_local *local,

net/mac80211/ieee80211_i.h

@@ -1559,6 +1559,8 @@ struct ieee80211_local {
 
 	/* extended capabilities provided by mac80211 */
 	u8 ext_capa[8];
+
+	bool wbrf_supported;
 };
 
 static inline struct ieee80211_sub_if_data *
@@ -2600,4 +2602,9 @@ ieee80211_eht_cap_ie_to_sta_eht_cap(struct ieee80211_sub_if_data *sdata,
 				    const struct ieee80211_eht_cap_elem *eht_cap_ie_elem,
 				    u8 eht_cap_len,
 				    struct link_sta_info *link_sta);
+
+void ieee80211_check_wbrf_support(struct ieee80211_local *local);
+void ieee80211_add_wbrf(struct ieee80211_local *local, struct cfg80211_chan_def *chandef);
+void ieee80211_remove_wbrf(struct ieee80211_local *local, struct cfg80211_chan_def *chandef);
+
 #endif /* IEEE80211_I_H */

net/mac80211/main.c

@@ -1405,6 +1405,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	debugfs_hw_add(local);
 	rate_control_add_debugfs(local);
 
+	ieee80211_check_wbrf_support(local);
+
 	rtnl_lock();
 	wiphy_lock(hw->wiphy);
 

net/mac80211/wbrf.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Wifi Band Exclusion Interface for WLAN
+ * Copyright (C) 2023 Advanced Micro Devices
+ *
+ */
+
+#include <linux/acpi_amd_wbrf.h>
+#include <linux/units.h>
+#include <net/cfg80211.h>
+#include "ieee80211_i.h"
+
+void ieee80211_check_wbrf_support(struct ieee80211_local *local)
+{
+	struct wiphy *wiphy = local->hw.wiphy;
+	struct device *dev;
+
+	if (!wiphy)
+		return;
+
+	dev = wiphy->dev.parent;
+	if (!dev)
+		return;
+
+	local->wbrf_supported = acpi_amd_wbrf_supported_producer(dev);
+	dev_dbg(dev, "WBRF is %s supported\n",
+		local->wbrf_supported ? "" : "not");
+}
+
+static void get_chan_freq_boundary(u32 center_freq, u32 bandwidth, u64 *start, u64 *end)
+{
+	bandwidth *= KHZ_PER_MHZ;
+	center_freq *= KHZ_PER_MHZ;
+
+	*start = center_freq - bandwidth / 2;
+	*end = center_freq + bandwidth / 2;
+
+	/* Frequency in Hz is expected */
+	*start = *start * HZ_PER_KHZ;
+	*end = *end * HZ_PER_KHZ;
+}
+
+static void get_ranges_from_chandef(struct cfg80211_chan_def *chandef,
+				    struct wbrf_ranges_in_out *ranges_in)
+{
+	u64 start_freq1, end_freq1;
+	u64 start_freq2, end_freq2;
+	int bandwidth;
+
+	bandwidth = nl80211_chan_width_to_mhz(chandef->width);
+
+	get_chan_freq_boundary(chandef->center_freq1, bandwidth, &start_freq1, &end_freq1);
+
+	ranges_in->band_list[0].start = start_freq1;
+	ranges_in->band_list[0].end = end_freq1;
+	ranges_in->num_of_ranges = 1;
+
+	if (chandef->width == NL80211_CHAN_WIDTH_80P80) {
+		get_chan_freq_boundary(chandef->center_freq2, bandwidth, &start_freq2, &end_freq2);
+
+		ranges_in->band_list[1].start = start_freq2;
+		ranges_in->band_list[1].end = end_freq2;
+		ranges_in->num_of_ranges++;
+	}
+}
+
+void ieee80211_add_wbrf(struct ieee80211_local *local, struct cfg80211_chan_def *chandef)
+{
+	struct wbrf_ranges_in_out ranges_in = {0};
+	struct device *dev;
+
+	if (!local->wbrf_supported)
+		return;
+
+	dev = local->hw.wiphy->dev.parent;
+
+	get_ranges_from_chandef(chandef, &ranges_in);
+
+	acpi_amd_wbrf_add_remove(dev, WBRF_RECORD_ADD, &ranges_in);
+}
+
+void ieee80211_remove_wbrf(struct ieee80211_local *local, struct cfg80211_chan_def *chandef)
+{
+	struct wbrf_ranges_in_out ranges_in = {0};
+	struct device *dev;
+
+	if (!local->wbrf_supported)
+		return;
+
+	dev = local->hw.wiphy->dev.parent;
+
+	get_ranges_from_chandef(chandef, &ranges_in);
+
+	acpi_amd_wbrf_add_remove(dev, WBRF_RECORD_REMOVE, &ranges_in);
+}