iwlwifi: bring in some of the rs code

Bring in code to call into rs-fw.c functionality for firmware
supported rate select.

Anything before AX200 (firmware matching iwlwiif-[0-9]*.ucode) will
still need further implementation, and so does iwl_mvm_rs_tx_status().
These bits marked with compat.linuxkpi.80211.debug TODO()s for now.

Implement some lindebugfs bits to gather more statistical information.

Sponsored by:	The FreeBSD Foundation

(cherry picked from commit 3f8cfb8a3a3b9fbe6d4aebde81aee80f8e89e2ea)

sys/contrib/dev/iwlwifi/mvm/rs.c

@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2020-2021 The FreeBSD Foundation
+ * Copyright (c) 2020-2025 The FreeBSD Foundation
  *
  * This software was developed by Björn Zeeb under sponsorship from
  * the FreeBSD Foundation.
@@ -33,42 +33,123 @@
  * This file is left as a wrapper to make mvm compile and we will only
  * deal with it on a need basis.  Most newer chipsets do this in firmware.
  */
+#include <sys/param.h>
+#include <net/cfg80211.h>		/* LinuxKPI 802.11 TODO() calls. */
 
-#include <sys/errno.h>
-
+#include "rs.h"
 #include "mvm.h"
 
 #ifdef CONFIG_IWLWIFI_DEBUGFS
+/*
+ * Fill struct iwl_mvm_frame_stats.
+ * Deal with various RATE_MCS_*_MSK. See rx.c, fw/api/rs.h, et al.
+ * XXX-BZ consider calling iwl_new_rate_from_v1() in rx.c so we can also
+ * use this in rxmq.c.
+ */
 void
 iwl_mvm_update_frame_stats(struct iwl_mvm *mvm, u32 rate, bool agg)
 {
+	uint8_t nss;
 
+	spin_lock_bh(&mvm->drv_stats_lock);
+	mvm->drv_rx_stats.success_frames++;
+
+	if (rate & RATE_MCS_HT_MSK_V1) {
+		mvm->drv_rx_stats.ht_frames++;
+		nss = 1 + ((rate & RATE_HT_MCS_NSS_MSK_V1) >> RATE_HT_MCS_NSS_POS_V1);
+	} else if (rate & RATE_MCS_VHT_MSK_V1) {
+		mvm->drv_rx_stats.vht_frames++;
+		nss = 1 + FIELD_GET(RATE_MCS_NSS_MSK, rate);
+	} else {
+		mvm->drv_rx_stats.legacy_frames++;
+		nss = 0;
+	}
+
+	switch (rate & RATE_MCS_CHAN_WIDTH_MSK_V1) {
+	case RATE_MCS_CHAN_WIDTH_20:
+		mvm->drv_rx_stats.bw_20_frames++;
+		break;
+	case RATE_MCS_CHAN_WIDTH_40:
+		mvm->drv_rx_stats.bw_40_frames++;
+		break;
+	case RATE_MCS_CHAN_WIDTH_80:
+		mvm->drv_rx_stats.bw_80_frames++;
+		break;
+	case RATE_MCS_CHAN_WIDTH_160:
+		mvm->drv_rx_stats.bw_160_frames++;
+		break;
+	}
+
+	if ((rate & RATE_MCS_CCK_MSK_V1) == 0 &&
+	    (rate & RATE_MCS_SGI_MSK_V1) != 0)
+		mvm->drv_rx_stats.sgi_frames++;
+	else
+		mvm->drv_rx_stats.ngi_frames++;
+
+	switch (nss) {
+	case 1:
+		mvm->drv_rx_stats.siso_frames++;
+		break;
+	case 2:
+		mvm->drv_rx_stats.mimo2_frames++;
+		break;
+	}
+
+	if (agg)
+		mvm->drv_rx_stats.agg_frames++;
+
+	/* ampdu_count? */
+	/* fail_frames? */
+
+	mvm->drv_rx_stats.last_rates[mvm->drv_rx_stats.last_frame_idx] = rate;
+	mvm->drv_rx_stats.last_frame_idx++;
+	mvm->drv_rx_stats.last_frame_idx %=
+	    ARRAY_SIZE(mvm->drv_rx_stats.last_rates);
+
+	spin_unlock_bh(&mvm->drv_stats_lock);
 }
 
 void
 iwl_mvm_reset_frame_stats(struct iwl_mvm *mvm)
 {
-
+	/* Apply same locking rx.c does; debugfs seems to read unloked? */
+	spin_lock_bh(&mvm->drv_stats_lock);
+	memset(&mvm->drv_rx_stats, 0, sizeof(mvm->drv_rx_stats));
+	spin_unlock_bh(&mvm->drv_stats_lock);
 }
 #endif
 
 int
 iwl_mvm_rate_control_register(void)
 {
-
-	return (0);
-}
-
-int
-iwl_mvm_tx_protection(struct iwl_mvm *mvm, struct iwl_mvm_sta *sta, bool enable)
-{
-
+	TODO("This likely has to call into net80211 unless we gain compat code in LinuxKPI");
 	return (0);
 }
 
 void
 iwl_mvm_rate_control_unregister(void)
 {
+	TODO("This likely has to call into net80211 unless we gain compat code in LinuxKPI");
+}
+
+int
+iwl_mvm_tx_protection(struct iwl_mvm *mvm, struct iwl_mvm_sta *mvmsta, bool enable)
+{
+	if (iwl_mvm_has_tlc_offload(mvm))
+		return (rs_fw_tx_protection(mvm, mvmsta, enable));
+        else {
+		TODO();
+		return (0);
+	}
+}
+
+static void
+iwl_mvm_rs_sw_rate_init(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
+    struct ieee80211_sta *sta,
+    struct ieee80211_bss_conf *link_conf, struct ieee80211_link_sta *link_sta,
+    enum nl80211_band band)
+{
+	TODO();
 }
 
 void
@@ -77,18 +158,28 @@ iwl_mvm_rs_rate_init(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
     struct ieee80211_bss_conf *link_conf, struct ieee80211_link_sta *link_sta,
     enum nl80211_band band)
 {
+	if (iwl_mvm_has_tlc_offload(mvm))
+		iwl_mvm_rs_fw_rate_init(mvm, vif, sta, link_conf, link_sta, band);
+	else
+		iwl_mvm_rs_sw_rate_init(mvm, vif, sta, link_conf, link_sta, band);
 }
 
 void
 iwl_mvm_rs_tx_status(struct iwl_mvm *mvm, struct ieee80211_sta *sta, int tid,
     struct ieee80211_tx_info *ba_info, bool t)
 {
+	TODO();
 }
 
 void
-rs_update_last_rssi(struct iwl_mvm *mvm, struct iwl_mvm_sta *mvmsta,
+rs_update_last_rssi(struct iwl_mvm *mvm __unused, struct iwl_mvm_sta *mvmsta,
     struct ieee80211_rx_status *rx_status)
 {
+	struct iwl_lq_sta *lq_sta;
+	int i;
+
+	if (mvmsta == NULL || rx_status == NULL)
+		return;
 
 	/*
 	 * Assumption based on mvm/sta.h is that this should update
@@ -96,12 +187,28 @@ rs_update_last_rssi(struct iwl_mvm *mvm, struct iwl_mvm_sta *mvmsta,
 	 * access in that struct so nowhere to put rssi information.
 	 * So the only thing would be if this is required internally
 	 * to functions in this file.
+	 * The "FW" version accesses more fields.  We assume they
+	 * are the same for now.
 	 */
+
+	lq_sta = &mvmsta->deflink.lq_sta.rs_drv;
+
+	lq_sta->pers.last_rssi = S8_MIN;
+	lq_sta->pers.chains = rx_status->chains;
+
+	for (i = 0; i < nitems(lq_sta->pers.chain_signal); i++) {
+		if ((rx_status->chains & BIT(i)) == 0)
+			continue;
+
+		lq_sta->pers.chain_signal[i] = rx_status->chain_signal[i];
+		if (rx_status->chain_signal[i] > lq_sta->pers.last_rssi)
+			lq_sta->pers.last_rssi = rx_status->chain_signal[i];
+	}
 }
 
 int
 rs_pretty_print_rate_v1(char *buf, int bufsz, const u32 rate)
 {
-
+	TODO();
 	return (0);
 }

sys/contrib/dev/iwlwifi/mvm/rs.h

@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2020-2021 The FreeBSD Foundation
+ * Copyright (c) 2020-2025 The FreeBSD Foundation
  *
  * This software was developed by Björn Zeeb under sponsorship from
  * the FreeBSD Foundation.
@@ -69,6 +69,13 @@ struct iwl_lq_sta {
 	struct {
 		spinlock_t	lock;
 		uint16_t	max_agg_bufsize;
+		/*
+		 * Based on the assumption that these are in "FW" too and
+		 * there is a f() to set last_rssi add them here too.
+		 */
+		uint8_t		chains;
+		uint8_t		chain_signal[IEEE80211_MAX_CHAINS];
+		uint8_t		last_rssi;
 	} pers;
 };