Contributors: 13
Author Tokens Token Proportion Commits Commit Proportion
Miri Korenblit 5487 96.86% 2 8.00%
Ilan Peer 46 0.81% 1 4.00%
Yedidya Benshimol 36 0.64% 1 4.00%
Daniel Gabay 25 0.44% 1 4.00%
Johannes Berg 22 0.39% 5 20.00%
Emmanuel Grumbach 14 0.25% 6 24.00%
Anjaneyulu 11 0.19% 2 8.00%
David Spinadel 9 0.16% 2 8.00%
Don Fry 6 0.11% 1 4.00%
Yi Zhu 4 0.07% 1 4.00%
Nathan Errera 3 0.05% 1 4.00%
Sara Sharon 1 0.02% 1 4.00%
Reinette Chatre 1 0.02% 1 4.00%
Total 5665 25 


// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
 * Copyright (C) 2024-2025 Intel Corporation
 */

#include <linux/ieee80211.h>
#include <kunit/static_stub.h>

#include "sta.h"
#include "hcmd.h"
#include "iface.h"
#include "mlo.h"
#include "key.h"
#include "agg.h"
#include "tlc.h"
#include "fw/api/sta.h"
#include "fw/api/mac.h"
#include "fw/api/rx.h"

int iwl_mld_fw_sta_id_from_link_sta(struct iwl_mld *mld,
				    struct ieee80211_link_sta *link_sta)
{
	struct iwl_mld_link_sta *mld_link_sta;

	/* This function should only be used with the wiphy lock held,
	 * In other cases, it is not guaranteed that the link_sta will exist
	 * in the driver too, and it is checked here.
	 */
	lockdep_assert_wiphy(mld->wiphy);

	/* This is not meant to be called with a NULL pointer */
	if (WARN_ON(!link_sta))
		return -ENOENT;

	mld_link_sta = iwl_mld_link_sta_from_mac80211(link_sta);
	if (!mld_link_sta) {
		WARN_ON(!iwl_mld_error_before_recovery(mld));
		return -ENOENT;
	}

	return mld_link_sta->fw_id;
}

static void
iwl_mld_fill_ampdu_size_and_dens(struct ieee80211_link_sta *link_sta,
				 struct ieee80211_bss_conf *link,
				 __le32 *tx_ampdu_max_size,
				 __le32 *tx_ampdu_spacing)
{
	u32 agg_size = 0, mpdu_dens = 0;

	if (WARN_ON(!link_sta || !link))
		return;

	/* Note that we always use only legacy & highest supported PPDUs, so
	 * of Draft P802.11be D.30 Table 10-12a--Fields used for calculating
	 * the maximum A-MPDU size of various PPDU types in different bands,
	 * we only need to worry about the highest supported PPDU type here.
	 */

	if (link_sta->ht_cap.ht_supported) {
		agg_size = link_sta->ht_cap.ampdu_factor;
		mpdu_dens = link_sta->ht_cap.ampdu_density;
	}

	if (link->chanreq.oper.chan->band == NL80211_BAND_6GHZ) {
		/* overwrite HT values on 6 GHz */
		mpdu_dens =
			le16_get_bits(link_sta->he_6ghz_capa.capa,
				      IEEE80211_HE_6GHZ_CAP_MIN_MPDU_START);
		agg_size =
			le16_get_bits(link_sta->he_6ghz_capa.capa,
				      IEEE80211_HE_6GHZ_CAP_MAX_AMPDU_LEN_EXP);
	} else if (link_sta->vht_cap.vht_supported) {
		/* if VHT supported overwrite HT value */
		agg_size =
			u32_get_bits(link_sta->vht_cap.cap,
				     IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK);
	}

	/* D6.0 10.12.2 A-MPDU length limit rules
	 * A STA indicates the maximum length of the A-MPDU preEOF padding
	 * that it can receive in an HE PPDU in the Maximum A-MPDU Length
	 * Exponent field in its HT Capabilities, VHT Capabilities,
	 * and HE 6 GHz Band Capabilities elements (if present) and the
	 * Maximum AMPDU Length Exponent Extension field in its HE
	 * Capabilities element
	 */
	if (link_sta->he_cap.has_he)
		agg_size +=
			u8_get_bits(link_sta->he_cap.he_cap_elem.mac_cap_info[3],
				    IEEE80211_HE_MAC_CAP3_MAX_AMPDU_LEN_EXP_MASK);

	if (link_sta->eht_cap.has_eht)
		agg_size +=
			u8_get_bits(link_sta->eht_cap.eht_cap_elem.mac_cap_info[1],
				    IEEE80211_EHT_MAC_CAP1_MAX_AMPDU_LEN_MASK);

	/* Limit to max A-MPDU supported by FW */
	agg_size = min_t(u32, agg_size,
			 STA_FLG_MAX_AGG_SIZE_4M >> STA_FLG_MAX_AGG_SIZE_SHIFT);

	*tx_ampdu_max_size = cpu_to_le32(agg_size);
	*tx_ampdu_spacing = cpu_to_le32(mpdu_dens);
}

static u8 iwl_mld_get_uapsd_acs(struct ieee80211_sta *sta)
{
	u8 uapsd_acs = 0;

	if (sta->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_BK)
		uapsd_acs |= BIT(AC_BK);
	if (sta->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_BE)
		uapsd_acs |= BIT(AC_BE);
	if (sta->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VI)
		uapsd_acs |= BIT(AC_VI);
	if (sta->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO)
		uapsd_acs |= BIT(AC_VO);

	return uapsd_acs | uapsd_acs << 4;
}

static u8 iwl_mld_he_get_ppe_val(u8 *ppe, u8 ppe_pos_bit)
{
	u8 byte_num = ppe_pos_bit / 8;
	u8 bit_num = ppe_pos_bit % 8;
	u8 residue_bits;
	u8 res;

	if (bit_num <= 5)
		return (ppe[byte_num] >> bit_num) &
		       (BIT(IEEE80211_PPE_THRES_INFO_PPET_SIZE) - 1);

	/* If bit_num > 5, we have to combine bits with next byte.
	 * Calculate how many bits we need to take from current byte (called
	 * here "residue_bits"), and add them to bits from next byte.
	 */

	residue_bits = 8 - bit_num;

	res = (ppe[byte_num + 1] &
	       (BIT(IEEE80211_PPE_THRES_INFO_PPET_SIZE - residue_bits) - 1)) <<
	      residue_bits;
	res += (ppe[byte_num] >> bit_num) & (BIT(residue_bits) - 1);

	return res;
}

static void iwl_mld_parse_ppe(struct iwl_mld *mld,
			      struct iwl_he_pkt_ext_v2 *pkt_ext, u8 nss,
			      u8 ru_index_bitmap, u8 *ppe, u8 ppe_pos_bit,
			      bool inheritance)
{
	/* FW currently supports only nss == MAX_HE_SUPP_NSS
	 *
	 * If nss > MAX: we can ignore values we don't support
	 * If nss < MAX: we can set zeros in other streams
	 */
	if (nss > MAX_HE_SUPP_NSS) {
		IWL_DEBUG_INFO(mld, "Got NSS = %d - trimming to %d\n", nss,
			       MAX_HE_SUPP_NSS);
		nss = MAX_HE_SUPP_NSS;
	}

	for (int i = 0; i < nss; i++) {
		u8 ru_index_tmp = ru_index_bitmap << 1;
		u8 low_th = IWL_HE_PKT_EXT_NONE, high_th = IWL_HE_PKT_EXT_NONE;

		for (u8 bw = 0;
		     bw < ARRAY_SIZE(pkt_ext->pkt_ext_qam_th[i]);
		     bw++) {
			ru_index_tmp >>= 1;

			/* According to the 11be spec, if for a specific BW the PPE Thresholds
			 * isn't present - it should inherit the thresholds from the last
			 * BW for which we had PPE Thresholds. In 11ax though, we don't have
			 * this inheritance - continue in this case
			 */
			if (!(ru_index_tmp & 1)) {
				if (inheritance)
					goto set_thresholds;
				else
					continue;
			}

			high_th = iwl_mld_he_get_ppe_val(ppe, ppe_pos_bit);
			ppe_pos_bit += IEEE80211_PPE_THRES_INFO_PPET_SIZE;
			low_th = iwl_mld_he_get_ppe_val(ppe, ppe_pos_bit);
			ppe_pos_bit += IEEE80211_PPE_THRES_INFO_PPET_SIZE;

set_thresholds:
			pkt_ext->pkt_ext_qam_th[i][bw][0] = low_th;
			pkt_ext->pkt_ext_qam_th[i][bw][1] = high_th;
		}
	}
}

static void iwl_mld_set_pkt_ext_from_he_ppe(struct iwl_mld *mld,
					    struct ieee80211_link_sta *link_sta,
					    struct iwl_he_pkt_ext_v2 *pkt_ext,
					    bool inheritance)
{
	u8 nss = (link_sta->he_cap.ppe_thres[0] &
		  IEEE80211_PPE_THRES_NSS_MASK) + 1;
	u8 *ppe = &link_sta->he_cap.ppe_thres[0];
	u8 ru_index_bitmap =
		u8_get_bits(*ppe,
			    IEEE80211_PPE_THRES_RU_INDEX_BITMASK_MASK);
	/* Starting after PPE header */
	u8 ppe_pos_bit = IEEE80211_HE_PPE_THRES_INFO_HEADER_SIZE;

	iwl_mld_parse_ppe(mld, pkt_ext, nss, ru_index_bitmap, ppe, ppe_pos_bit,
			  inheritance);
}

static int
iwl_mld_set_pkt_ext_from_nominal_padding(struct iwl_he_pkt_ext_v2 *pkt_ext,
					 u8 nominal_padding)
{
	int low_th = -1;
	int high_th = -1;

	/* all the macros are the same for EHT and HE */
	switch (nominal_padding) {
	case IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_0US:
		low_th = IWL_HE_PKT_EXT_NONE;
		high_th = IWL_HE_PKT_EXT_NONE;
		break;
	case IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_8US:
		low_th = IWL_HE_PKT_EXT_BPSK;
		high_th = IWL_HE_PKT_EXT_NONE;
		break;
	case IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_16US:
	case IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_20US:
		low_th = IWL_HE_PKT_EXT_NONE;
		high_th = IWL_HE_PKT_EXT_BPSK;
		break;
	}

	if (low_th < 0 || high_th < 0)
		return -EINVAL;

	/* Set the PPE thresholds accordingly */
	for (int i = 0; i < MAX_HE_SUPP_NSS; i++) {
		for (u8 bw = 0;
			bw < ARRAY_SIZE(pkt_ext->pkt_ext_qam_th[i]);
			bw++) {
			pkt_ext->pkt_ext_qam_th[i][bw][0] = low_th;
			pkt_ext->pkt_ext_qam_th[i][bw][1] = high_th;
		}
	}

	return 0;
}

static void iwl_mld_get_optimal_ppe_info(struct iwl_he_pkt_ext_v2 *pkt_ext,
					 u8 nominal_padding)
{
	for (int i = 0; i < MAX_HE_SUPP_NSS; i++) {
		for (u8 bw = 0; bw < ARRAY_SIZE(pkt_ext->pkt_ext_qam_th[i]);
		     bw++) {
			u8 *qam_th = &pkt_ext->pkt_ext_qam_th[i][bw][0];

			if (nominal_padding >
			    IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_8US &&
			    qam_th[1] == IWL_HE_PKT_EXT_NONE)
				qam_th[1] = IWL_HE_PKT_EXT_4096QAM;
			else if (nominal_padding ==
				 IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_8US &&
				 qam_th[0] == IWL_HE_PKT_EXT_NONE &&
				 qam_th[1] == IWL_HE_PKT_EXT_NONE)
				qam_th[0] = IWL_HE_PKT_EXT_4096QAM;
		}
	}
}

static void iwl_mld_fill_pkt_ext(struct iwl_mld *mld,
				 struct ieee80211_link_sta *link_sta,
				 struct iwl_he_pkt_ext_v2 *pkt_ext)
{
	if (WARN_ON(!link_sta))
		return;

	/* Initialize the PPE thresholds to "None" (7), as described in Table
	 * 9-262ac of 80211.ax/D3.0.
	 */
	memset(pkt_ext, IWL_HE_PKT_EXT_NONE, sizeof(*pkt_ext));

	if (link_sta->eht_cap.has_eht) {
		u8 nominal_padding =
			u8_get_bits(link_sta->eht_cap.eht_cap_elem.phy_cap_info[5],
				    IEEE80211_EHT_PHY_CAP5_COMMON_NOMINAL_PKT_PAD_MASK);

		/* If PPE Thresholds exists, parse them into a FW-familiar
		 * format.
		 */
		if (link_sta->eht_cap.eht_cap_elem.phy_cap_info[5] &
		    IEEE80211_EHT_PHY_CAP5_PPE_THRESHOLD_PRESENT) {
			u8 nss = (link_sta->eht_cap.eht_ppe_thres[0] &
				IEEE80211_EHT_PPE_THRES_NSS_MASK) + 1;
			u8 *ppe = &link_sta->eht_cap.eht_ppe_thres[0];
			u8 ru_index_bitmap =
				u16_get_bits(*ppe,
					     IEEE80211_EHT_PPE_THRES_RU_INDEX_BITMASK_MASK);
			 /* Starting after PPE header */
			u8 ppe_pos_bit = IEEE80211_EHT_PPE_THRES_INFO_HEADER_SIZE;

			iwl_mld_parse_ppe(mld, pkt_ext, nss, ru_index_bitmap,
					  ppe, ppe_pos_bit, true);
		/* EHT PPE Thresholds doesn't exist - set the API according to
		 * HE PPE Tresholds
		 */
		} else if (link_sta->he_cap.he_cap_elem.phy_cap_info[6] &
			   IEEE80211_HE_PHY_CAP6_PPE_THRESHOLD_PRESENT) {
			/* Even though HE Capabilities IE doesn't contain PPE
			 * Thresholds for BW 320Mhz, thresholds for this BW will
			 * be filled in with the same values as 160Mhz, due to
			 * the inheritance, as required.
			 */
			iwl_mld_set_pkt_ext_from_he_ppe(mld, link_sta, pkt_ext,
							true);

			/* According to the requirements, for MCSs 12-13 the
			 * maximum value between HE PPE Threshold and Common
			 * Nominal Packet Padding needs to be taken
			 */
			iwl_mld_get_optimal_ppe_info(pkt_ext, nominal_padding);

		/* if PPE Thresholds doesn't present in both EHT IE and HE IE -
		 * take the Thresholds from Common Nominal Packet Padding field
		 */
		} else {
			iwl_mld_set_pkt_ext_from_nominal_padding(pkt_ext,
								 nominal_padding);
		}
	} else if (link_sta->he_cap.has_he) {
		/* If PPE Thresholds exist, parse them into a FW-familiar format. */
		if (link_sta->he_cap.he_cap_elem.phy_cap_info[6] &
			IEEE80211_HE_PHY_CAP6_PPE_THRESHOLD_PRESENT) {
			iwl_mld_set_pkt_ext_from_he_ppe(mld, link_sta, pkt_ext,
							false);
		/* PPE Thresholds doesn't exist - set the API PPE values
		 * according to Common Nominal Packet Padding field.
		 */
		} else {
			u8 nominal_padding =
				u8_get_bits(link_sta->he_cap.he_cap_elem.phy_cap_info[9],
					    IEEE80211_HE_PHY_CAP9_NOMINAL_PKT_PADDING_MASK);
			if (nominal_padding != IEEE80211_HE_PHY_CAP9_NOMINAL_PKT_PADDING_RESERVED)
				iwl_mld_set_pkt_ext_from_nominal_padding(pkt_ext,
									 nominal_padding);
		}
	}

	for (int i = 0; i < MAX_HE_SUPP_NSS; i++) {
		for (int bw = 0;
		     bw < ARRAY_SIZE(*pkt_ext->pkt_ext_qam_th[i]);
		     bw++) {
			u8 *qam_th =
				&pkt_ext->pkt_ext_qam_th[i][bw][0];

			IWL_DEBUG_HT(mld,
				     "PPE table: nss[%d] bw[%d] PPET8 = %d, PPET16 = %d\n",
				     i, bw, qam_th[0], qam_th[1]);
		}
	}
}

static u32 iwl_mld_get_htc_flags(struct ieee80211_link_sta *link_sta)
{
	u8 *mac_cap_info =
		&link_sta->he_cap.he_cap_elem.mac_cap_info[0];
	u32 htc_flags = 0;

	if (mac_cap_info[0] & IEEE80211_HE_MAC_CAP0_HTC_HE)
		htc_flags |= IWL_HE_HTC_SUPPORT;
	if ((mac_cap_info[1] & IEEE80211_HE_MAC_CAP1_LINK_ADAPTATION) ||
	    (mac_cap_info[2] & IEEE80211_HE_MAC_CAP2_LINK_ADAPTATION)) {
		u8 link_adap =
			((mac_cap_info[2] &
			  IEEE80211_HE_MAC_CAP2_LINK_ADAPTATION) << 1) +
			 (mac_cap_info[1] &
			  IEEE80211_HE_MAC_CAP1_LINK_ADAPTATION);

		if (link_adap == 2)
			htc_flags |=
				IWL_HE_HTC_LINK_ADAP_UNSOLICITED;
		else if (link_adap == 3)
			htc_flags |= IWL_HE_HTC_LINK_ADAP_BOTH;
	}
	if (mac_cap_info[2] & IEEE80211_HE_MAC_CAP2_BSR)
		htc_flags |= IWL_HE_HTC_BSR_SUPP;
	if (mac_cap_info[3] & IEEE80211_HE_MAC_CAP3_OMI_CONTROL)
		htc_flags |= IWL_HE_HTC_OMI_SUPP;
	if (mac_cap_info[4] & IEEE80211_HE_MAC_CAP4_BQR)
		htc_flags |= IWL_HE_HTC_BQR_SUPP;

	return htc_flags;
}

static int iwl_mld_send_sta_cmd(struct iwl_mld *mld,
				const struct iwl_sta_cfg_cmd *cmd)
{
	u32 cmd_id = WIDE_ID(MAC_CONF_GROUP, STA_CONFIG_CMD);
	int cmd_len = iwl_fw_lookup_cmd_ver(mld->fw, cmd_id, 0) > 1 ?
		      sizeof(*cmd) :
		      sizeof(struct iwl_sta_cfg_cmd_v1);
	int ret = iwl_mld_send_cmd_pdu(mld, cmd_id, cmd, cmd_len);
	if (ret)
		IWL_ERR(mld, "STA_CONFIG_CMD send failed, ret=0x%x\n", ret);
	return ret;
}

static int
iwl_mld_add_modify_sta_cmd(struct iwl_mld *mld,
			   struct ieee80211_link_sta *link_sta)
{
	struct ieee80211_sta *sta = link_sta->sta;
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(sta);
	struct ieee80211_bss_conf *link;
	struct iwl_mld_link *mld_link;
	struct iwl_sta_cfg_cmd cmd = {};
	int fw_id = iwl_mld_fw_sta_id_from_link_sta(mld, link_sta);

	lockdep_assert_wiphy(mld->wiphy);

	link = link_conf_dereference_protected(mld_sta->vif,
					       link_sta->link_id);

	mld_link = iwl_mld_link_from_mac80211(link);

	if (WARN_ON(!link || !mld_link) || fw_id < 0)
		return -EINVAL;

	cmd.sta_id = cpu_to_le32(fw_id);
	cmd.station_type = cpu_to_le32(mld_sta->sta_type);
	cmd.link_id = cpu_to_le32(mld_link->fw_id);

	memcpy(&cmd.peer_mld_address, sta->addr, ETH_ALEN);
	memcpy(&cmd.peer_link_address, link_sta->addr, ETH_ALEN);

	if (mld_sta->sta_state >= IEEE80211_STA_ASSOC)
		cmd.assoc_id = cpu_to_le32(sta->aid);

	if (sta->mfp || mld_sta->sta_state < IEEE80211_STA_AUTHORIZED)
		cmd.mfp = cpu_to_le32(1);

	switch (link_sta->rx_nss) {
	case 1:
		cmd.mimo = cpu_to_le32(0);
		break;
	case 2 ... 8:
		cmd.mimo = cpu_to_le32(1);
		break;
	}

	switch (link_sta->smps_mode) {
	case IEEE80211_SMPS_AUTOMATIC:
	case IEEE80211_SMPS_NUM_MODES:
		WARN_ON(1);
		break;
	case IEEE80211_SMPS_STATIC:
		/* override NSS */
		cmd.mimo = cpu_to_le32(0);
		break;
	case IEEE80211_SMPS_DYNAMIC:
		cmd.mimo_protection = cpu_to_le32(1);
		break;
	case IEEE80211_SMPS_OFF:
		/* nothing */
		break;
	}

	iwl_mld_fill_ampdu_size_and_dens(link_sta, link,
					 &cmd.tx_ampdu_max_size,
					 &cmd.tx_ampdu_spacing);

	if (sta->wme) {
		cmd.sp_length =
			cpu_to_le32(sta->max_sp ? sta->max_sp * 2 : 128);
		cmd.uapsd_acs = cpu_to_le32(iwl_mld_get_uapsd_acs(sta));
	}

	if (link_sta->he_cap.has_he) {
		cmd.trig_rnd_alloc =
			cpu_to_le32(link->uora_exists ? 1 : 0);

		/* PPE Thresholds */
		iwl_mld_fill_pkt_ext(mld, link_sta, &cmd.pkt_ext);

		/* HTC flags */
		cmd.htc_flags =
			cpu_to_le32(iwl_mld_get_htc_flags(link_sta));

		if (link_sta->he_cap.he_cap_elem.mac_cap_info[2] &
		    IEEE80211_HE_MAC_CAP2_ACK_EN)
			cmd.ack_enabled = cpu_to_le32(1);
	}

	return iwl_mld_send_sta_cmd(mld, &cmd);
}

IWL_MLD_ALLOC_FN(link_sta, link_sta)

static int
iwl_mld_add_link_sta(struct iwl_mld *mld, struct ieee80211_link_sta *link_sta)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(link_sta->sta);
	struct iwl_mld_link_sta *mld_link_sta;
	int ret;
	u8 fw_id;

	lockdep_assert_wiphy(mld->wiphy);

	/* We will fail to add it to the FW anyway */
	if (iwl_mld_error_before_recovery(mld))
		return -ENODEV;

	mld_link_sta = iwl_mld_link_sta_from_mac80211(link_sta);

	/* We need to preserve the fw sta ids during a restart, since the fw
	 * will recover SN/PN for them, this is why the mld_link_sta exists.
	 */
	if (mld_link_sta) {
		/* But if we are not restarting, this is not OK */
		WARN_ON(!mld->fw_status.in_hw_restart);

		/* Avoid adding a STA that is already in FW to avoid an assert */
		if (WARN_ON(mld_link_sta->in_fw))
			return -EINVAL;

		fw_id = mld_link_sta->fw_id;
		goto add_to_fw;
	}

	/* Allocate a fw id and map it to the link_sta */
	ret = iwl_mld_allocate_link_sta_fw_id(mld, &fw_id, link_sta);
	if (ret)
		return ret;

	if (link_sta == &link_sta->sta->deflink) {
		mld_link_sta = &mld_sta->deflink;
	} else {
		mld_link_sta = kzalloc(sizeof(*mld_link_sta), GFP_KERNEL);
		if (!mld_link_sta)
			return -ENOMEM;
	}

	mld_link_sta->fw_id = fw_id;
	rcu_assign_pointer(mld_sta->link[link_sta->link_id], mld_link_sta);

add_to_fw:
	ret = iwl_mld_add_modify_sta_cmd(mld, link_sta);
	if (ret) {
		RCU_INIT_POINTER(mld->fw_id_to_link_sta[fw_id], NULL);
		RCU_INIT_POINTER(mld_sta->link[link_sta->link_id], NULL);
		if (link_sta != &link_sta->sta->deflink)
			kfree(mld_link_sta);
		return ret;
	}
	mld_link_sta->in_fw = true;

	return 0;
}

static int iwl_mld_rm_sta_from_fw(struct iwl_mld *mld, u8 fw_sta_id)
{
	struct iwl_remove_sta_cmd cmd = {
		.sta_id = cpu_to_le32(fw_sta_id),
	};
	int ret;

	ret = iwl_mld_send_cmd_pdu(mld,
				   WIDE_ID(MAC_CONF_GROUP, STA_REMOVE_CMD),
				   &cmd);
	if (ret)
		IWL_ERR(mld, "Failed to remove station. Id=%d\n", fw_sta_id);

	return ret;
}

static void
iwl_mld_remove_link_sta(struct iwl_mld *mld,
			struct ieee80211_link_sta *link_sta)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(link_sta->sta);
	struct iwl_mld_link_sta *mld_link_sta =
		iwl_mld_link_sta_from_mac80211(link_sta);

	if (WARN_ON(!mld_link_sta))
		return;

	iwl_mld_rm_sta_from_fw(mld, mld_link_sta->fw_id);
	mld_link_sta->in_fw = false;

	/* Now that the STA doesn't exist in FW, we don't expect any new
	 * notifications for it. Cancel the ones that are already pending
	 */
	iwl_mld_cancel_notifications_of_object(mld, IWL_MLD_OBJECT_TYPE_STA,
					       mld_link_sta->fw_id);

	/* This will not be done upon reconfig, so do it also when
	 * failed to remove from fw
	 */
	RCU_INIT_POINTER(mld->fw_id_to_link_sta[mld_link_sta->fw_id], NULL);
	RCU_INIT_POINTER(mld_sta->link[link_sta->link_id], NULL);
	if (mld_link_sta != &mld_sta->deflink)
		kfree_rcu(mld_link_sta, rcu_head);
}

static void iwl_mld_set_max_amsdu_len(struct iwl_mld *mld,
				      struct ieee80211_link_sta *link_sta)
{
	const struct ieee80211_sta_ht_cap *ht_cap = &link_sta->ht_cap;

	/* For EHT, HE and VHT we can use the value as it was calculated by
	 * mac80211. For HT, mac80211 doesn't enforce to 4095, so force it
	 * here
	 */
	if (link_sta->eht_cap.has_eht || link_sta->he_cap.has_he ||
	    link_sta->vht_cap.vht_supported ||
	    !ht_cap->ht_supported ||
	    !(ht_cap->cap & IEEE80211_HT_CAP_MAX_AMSDU))
		return;

	link_sta->agg.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_BA;
	ieee80211_sta_recalc_aggregates(link_sta->sta);
}

int iwl_mld_update_all_link_stations(struct iwl_mld *mld,
				     struct ieee80211_sta *sta)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(sta);
	struct ieee80211_link_sta *link_sta;
	int link_id;

	for_each_sta_active_link(mld_sta->vif, sta, link_sta, link_id) {
		int ret = iwl_mld_add_modify_sta_cmd(mld, link_sta);

		if (ret)
			return ret;

		if (mld_sta->sta_state == IEEE80211_STA_ASSOC)
			iwl_mld_set_max_amsdu_len(mld, link_sta);
	}
	return 0;
}

static void iwl_mld_destroy_sta(struct ieee80211_sta *sta)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(sta);

	kfree(mld_sta->dup_data);
	kfree(mld_sta->mpdu_counters);
}

static int
iwl_mld_alloc_dup_data(struct iwl_mld *mld, struct iwl_mld_sta *mld_sta)
{
	struct iwl_mld_rxq_dup_data *dup_data;

	if (mld->fw_status.in_hw_restart)
		return 0;

	dup_data = kcalloc(mld->trans->info.num_rxqs, sizeof(*dup_data),
			   GFP_KERNEL);
	if (!dup_data)
		return -ENOMEM;

	/* Initialize all the last_seq values to 0xffff which can never
	 * compare equal to the frame's seq_ctrl in the check in
	 * iwl_mld_is_dup() since the lower 4 bits are the fragment
	 * number and fragmented packets don't reach that function.
	 *
	 * This thus allows receiving a packet with seqno 0 and the
	 * retry bit set as the very first packet on a new TID.
	 */
	for (int q = 0; q < mld->trans->info.num_rxqs; q++)
		memset(dup_data[q].last_seq, 0xff,
		       sizeof(dup_data[q].last_seq));
	mld_sta->dup_data = dup_data;

	return 0;
}

static void iwl_mld_alloc_mpdu_counters(struct iwl_mld *mld,
					struct ieee80211_sta *sta)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(sta);
	struct ieee80211_vif *vif = mld_sta->vif;

	if (mld->fw_status.in_hw_restart)
		return;

	/* MPDUs are counted only when EMLSR is possible */
	if (ieee80211_vif_type_p2p(vif) != NL80211_IFTYPE_STATION ||
	    sta->tdls || !ieee80211_vif_is_mld(vif))
		return;

	mld_sta->mpdu_counters = kcalloc(mld->trans->info.num_rxqs,
					 sizeof(*mld_sta->mpdu_counters),
					 GFP_KERNEL);
	if (!mld_sta->mpdu_counters)
		return;

	for (int q = 0; q < mld->trans->info.num_rxqs; q++)
		spin_lock_init(&mld_sta->mpdu_counters[q].lock);
}

static int
iwl_mld_init_sta(struct iwl_mld *mld, struct ieee80211_sta *sta,
		 struct ieee80211_vif *vif, enum iwl_fw_sta_type type)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(sta);

	mld_sta->vif = vif;
	mld_sta->sta_type = type;
	mld_sta->mld = mld;

	if (!mld->fw_status.in_hw_restart)
		for (int i = 0; i < ARRAY_SIZE(sta->txq); i++)
			iwl_mld_init_txq(iwl_mld_txq_from_mac80211(sta->txq[i]));

	iwl_mld_alloc_mpdu_counters(mld, sta);

	iwl_mld_toggle_tx_ant(mld, &mld_sta->data_tx_ant);

	return iwl_mld_alloc_dup_data(mld, mld_sta);
}

int iwl_mld_add_sta(struct iwl_mld *mld, struct ieee80211_sta *sta,
		    struct ieee80211_vif *vif, enum iwl_fw_sta_type type)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(sta);
	struct ieee80211_link_sta *link_sta;
	int link_id;
	int ret;

	ret = iwl_mld_init_sta(mld, sta, vif, type);
	if (ret)
		return ret;

	/* We could have add only the deflink link_sta, but it will not work
	 * in the restart case if the single link that is active during
	 * reconfig is not the deflink one.
	 */
	for_each_sta_active_link(mld_sta->vif, sta, link_sta, link_id) {
		ret = iwl_mld_add_link_sta(mld, link_sta);
		if (ret)
			goto destroy_sta;
	}

	return 0;

destroy_sta:
	iwl_mld_destroy_sta(sta);

	return ret;
}

void iwl_mld_flush_sta_txqs(struct iwl_mld *mld, struct ieee80211_sta *sta)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(sta);
	struct ieee80211_link_sta *link_sta;
	int link_id;

	for_each_sta_active_link(mld_sta->vif, sta, link_sta, link_id) {
		int fw_sta_id = iwl_mld_fw_sta_id_from_link_sta(mld, link_sta);

		if (fw_sta_id < 0)
			continue;

		iwl_mld_flush_link_sta_txqs(mld, fw_sta_id);
	}
}

void iwl_mld_wait_sta_txqs_empty(struct iwl_mld *mld, struct ieee80211_sta *sta)
{
	/* Avoid a warning in iwl_trans_wait_txq_empty if are anyway on the way
	 * to a restart.
	 */
	if (iwl_mld_error_before_recovery(mld))
		return;

	for (int i = 0; i < ARRAY_SIZE(sta->txq); i++) {
		struct iwl_mld_txq *mld_txq =
			iwl_mld_txq_from_mac80211(sta->txq[i]);

		if (!mld_txq->status.allocated)
			continue;

		iwl_trans_wait_txq_empty(mld->trans, mld_txq->fw_id);
	}
}

void iwl_mld_remove_sta(struct iwl_mld *mld, struct ieee80211_sta *sta)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(sta);
	struct ieee80211_vif *vif = mld_sta->vif;
	struct ieee80211_link_sta *link_sta;
	u8 link_id;

	lockdep_assert_wiphy(mld->wiphy);

	/* Tell the HW to flush the queues */
	iwl_mld_flush_sta_txqs(mld, sta);

	/* Wait for trans to empty its queues */
	iwl_mld_wait_sta_txqs_empty(mld, sta);

	/* Now we can remove the queues */
	for (int i = 0; i < ARRAY_SIZE(sta->txq); i++)
		iwl_mld_remove_txq(mld, sta->txq[i]);

	for_each_sta_active_link(vif, sta, link_sta, link_id) {
		/* Mac8011 will remove the groupwise keys after the sta is
		 * removed, but FW expects all the keys to be removed before
		 * the STA is, so remove them all here.
		 */
		if (vif->type == NL80211_IFTYPE_STATION && !sta->tdls)
			iwl_mld_remove_ap_keys(mld, vif, sta, link_id);

		/* Remove the link_sta */
		iwl_mld_remove_link_sta(mld, link_sta);
	}

	iwl_mld_destroy_sta(sta);
}

u32 iwl_mld_fw_sta_id_mask(struct iwl_mld *mld, struct ieee80211_sta *sta)
{
	struct ieee80211_vif *vif = iwl_mld_sta_from_mac80211(sta)->vif;
	struct ieee80211_link_sta *link_sta;
	unsigned int link_id;
	u32 result = 0;

	KUNIT_STATIC_STUB_REDIRECT(iwl_mld_fw_sta_id_mask, mld, sta);

	/* This function should only be used with the wiphy lock held,
	 * In other cases, it is not guaranteed that the link_sta will exist
	 * in the driver too, and it is checked in
	 * iwl_mld_fw_sta_id_from_link_sta.
	 */
	lockdep_assert_wiphy(mld->wiphy);

	for_each_sta_active_link(vif, sta, link_sta, link_id) {
		int fw_id = iwl_mld_fw_sta_id_from_link_sta(mld, link_sta);

		if (!(fw_id < 0))
			result |= BIT(fw_id);
	}

	return result;
}
EXPORT_SYMBOL_IF_IWLWIFI_KUNIT(iwl_mld_fw_sta_id_mask);

static void iwl_mld_count_mpdu(struct ieee80211_link_sta *link_sta, int queue,
			       u32 count, bool tx)
{
	struct iwl_mld_per_q_mpdu_counter *queue_counter;
	struct iwl_mld_per_link_mpdu_counter *link_counter;
	struct iwl_mld_vif *mld_vif;
	struct iwl_mld_sta *mld_sta;
	struct iwl_mld_link *mld_link;
	struct iwl_mld *mld;
	int total_mpdus = 0;

	if (WARN_ON(!link_sta))
		return;

	mld_sta = iwl_mld_sta_from_mac80211(link_sta->sta);
	if (!mld_sta->mpdu_counters)
		return;

	mld_vif = iwl_mld_vif_from_mac80211(mld_sta->vif);
	mld_link = iwl_mld_link_dereference_check(mld_vif, link_sta->link_id);

	if (WARN_ON_ONCE(!mld_link))
		return;

	queue_counter = &mld_sta->mpdu_counters[queue];

	mld = mld_vif->mld;

	/* If it the window is over, first clear the counters.
	 * When we are not blocked by TPT, the window is managed by check_tpt_wk
	 */
	if ((mld_vif->emlsr.blocked_reasons & IWL_MLD_EMLSR_BLOCKED_TPT) &&
	    time_is_before_jiffies(queue_counter->window_start_time +
					IWL_MLD_TPT_COUNT_WINDOW)) {
		memset(queue_counter->per_link, 0,
		       sizeof(queue_counter->per_link));
		queue_counter->window_start_time = jiffies;

		IWL_DEBUG_INFO(mld, "MPDU counters are cleared\n");
	}

	link_counter = &queue_counter->per_link[mld_link->fw_id];

	spin_lock_bh(&queue_counter->lock);

	/* Update the statistics for this TPT measurement window */
	if (tx)
		link_counter->tx += count;
	else
		link_counter->rx += count;

	/*
	 * Next, evaluate whether we should queue an unblock,
	 * skip this if we are not blocked due to low throughput.
	 */
	if (!(mld_vif->emlsr.blocked_reasons & IWL_MLD_EMLSR_BLOCKED_TPT))
		goto unlock;

	for (int i = 0; i <= IWL_FW_MAX_LINK_ID; i++)
		total_mpdus += tx ? queue_counter->per_link[i].tx :
				    queue_counter->per_link[i].rx;

	/* Unblock is already queued if the threshold was reached before */
	if (total_mpdus - count >= IWL_MLD_ENTER_EMLSR_TPT_THRESH)
		goto unlock;

	if (total_mpdus >= IWL_MLD_ENTER_EMLSR_TPT_THRESH)
		wiphy_work_queue(mld->wiphy, &mld_vif->emlsr.unblock_tpt_wk);

unlock:
	spin_unlock_bh(&queue_counter->lock);
}

/* must be called under rcu_read_lock() */
void iwl_mld_count_mpdu_rx(struct ieee80211_link_sta *link_sta, int queue,
			   u32 count)
{
	iwl_mld_count_mpdu(link_sta, queue, count, false);
}

/* must be called under rcu_read_lock() */
void iwl_mld_count_mpdu_tx(struct ieee80211_link_sta *link_sta, u32 count)
{
	/* use queue 0 for all TX */
	iwl_mld_count_mpdu(link_sta, 0, count, true);
}

static int iwl_mld_allocate_internal_txq(struct iwl_mld *mld,
					 struct iwl_mld_int_sta *internal_sta,
					 u8 tid)
{
	u32 sta_mask = BIT(internal_sta->sta_id);
	int queue, size;

	size = max_t(u32, IWL_MGMT_QUEUE_SIZE,
		     mld->trans->mac_cfg->base->min_txq_size);

	queue = iwl_trans_txq_alloc(mld->trans, 0, sta_mask, tid, size,
				    IWL_WATCHDOG_DISABLED);

	if (queue >= 0)
		IWL_DEBUG_TX_QUEUES(mld,
				    "Enabling TXQ #%d for sta mask 0x%x tid %d\n",
				    queue, sta_mask, tid);
	return queue;
}

static int iwl_mld_send_aux_sta_cmd(struct iwl_mld *mld,
				    const struct iwl_mld_int_sta *internal_sta)
{
	struct iwl_aux_sta_cmd cmd = {
		.sta_id = cpu_to_le32(internal_sta->sta_id),
		/* TODO: CDB - properly set the lmac_id */
		.lmac_id = cpu_to_le32(IWL_LMAC_24G_INDEX),
	};

	return iwl_mld_send_cmd_pdu(mld, WIDE_ID(MAC_CONF_GROUP, AUX_STA_CMD),
				    &cmd);
}

static int
iwl_mld_add_internal_sta_to_fw(struct iwl_mld *mld,
			       const struct iwl_mld_int_sta *internal_sta,
			       u8 fw_link_id,
			       const u8 *addr)
{
	struct iwl_sta_cfg_cmd cmd = {};

	if (internal_sta->sta_type == STATION_TYPE_AUX)
		return iwl_mld_send_aux_sta_cmd(mld, internal_sta);

	cmd.sta_id = cpu_to_le32((u8)internal_sta->sta_id);
	cmd.link_id = cpu_to_le32(fw_link_id);
	cmd.station_type = cpu_to_le32(internal_sta->sta_type);

	/* FW doesn't allow to add a IGTK/BIGTK if the sta isn't marked as MFP.
	 * On the other hand, FW will never check this flag during RX since
	 * an AP/GO doesn't receive protected broadcast management frames.
	 * So, we can set it unconditionally.
	 */
	if (internal_sta->sta_type == STATION_TYPE_BCAST_MGMT)
		cmd.mfp = cpu_to_le32(1);

	if (addr) {
		memcpy(cmd.peer_mld_address, addr, ETH_ALEN);
		memcpy(cmd.peer_link_address, addr, ETH_ALEN);
	}

	return iwl_mld_send_sta_cmd(mld, &cmd);
}

static int iwl_mld_add_internal_sta(struct iwl_mld *mld,
				    struct iwl_mld_int_sta *internal_sta,
				    enum iwl_fw_sta_type sta_type,
				    u8 fw_link_id, const u8 *addr, u8 tid)
{
	int ret, queue_id;

	ret = iwl_mld_allocate_link_sta_fw_id(mld,
					      &internal_sta->sta_id,
					      ERR_PTR(-EINVAL));
	if (ret)
		return ret;

	internal_sta->sta_type = sta_type;

	ret = iwl_mld_add_internal_sta_to_fw(mld, internal_sta, fw_link_id,
					     addr);
	if (ret)
		goto err;

	queue_id = iwl_mld_allocate_internal_txq(mld, internal_sta, tid);
	if (queue_id < 0) {
		iwl_mld_rm_sta_from_fw(mld, internal_sta->sta_id);
		ret = queue_id;
		goto err;
	}

	internal_sta->queue_id = queue_id;

	return 0;
err:
	iwl_mld_free_internal_sta(mld, internal_sta);
	return ret;
}

int iwl_mld_add_bcast_sta(struct iwl_mld *mld,
			  struct ieee80211_vif *vif,
			  struct ieee80211_bss_conf *link)
{
	struct iwl_mld_link *mld_link = iwl_mld_link_from_mac80211(link);
	const u8 bcast_addr[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
	const u8 *addr;

	if (WARN_ON(!mld_link))
		return -EINVAL;

	if (WARN_ON(vif->type != NL80211_IFTYPE_AP &&
		    vif->type != NL80211_IFTYPE_ADHOC))
		return -EINVAL;

	addr = vif->type == NL80211_IFTYPE_ADHOC ? link->bssid : bcast_addr;

	return iwl_mld_add_internal_sta(mld, &mld_link->bcast_sta,
					STATION_TYPE_BCAST_MGMT,
					mld_link->fw_id, addr,
					IWL_MGMT_TID);
}

int iwl_mld_add_mcast_sta(struct iwl_mld *mld,
			  struct ieee80211_vif *vif,
			  struct ieee80211_bss_conf *link)
{
	struct iwl_mld_link *mld_link = iwl_mld_link_from_mac80211(link);
	const u8 mcast_addr[] = {0x03, 0x00, 0x00, 0x00, 0x00, 0x00};

	if (WARN_ON(!mld_link))
		return -EINVAL;

	if (WARN_ON(vif->type != NL80211_IFTYPE_AP &&
		    vif->type != NL80211_IFTYPE_ADHOC))
		return -EINVAL;

	return iwl_mld_add_internal_sta(mld, &mld_link->mcast_sta,
					STATION_TYPE_MCAST,
					mld_link->fw_id, mcast_addr, 0);
}

int iwl_mld_add_aux_sta(struct iwl_mld *mld,
			struct iwl_mld_int_sta *internal_sta)
{
	return iwl_mld_add_internal_sta(mld, internal_sta, STATION_TYPE_AUX,
					0, NULL, IWL_MAX_TID_COUNT);
}

int iwl_mld_add_mon_sta(struct iwl_mld *mld,
			struct ieee80211_vif *vif,
			struct ieee80211_bss_conf *link)
{
	struct iwl_mld_link *mld_link = iwl_mld_link_from_mac80211(link);

	if (WARN_ON(!mld_link))
		return -EINVAL;

	if (WARN_ON(vif->type != NL80211_IFTYPE_MONITOR))
		return -EINVAL;

	return iwl_mld_add_internal_sta(mld, &mld_link->mon_sta,
					STATION_TYPE_BCAST_MGMT,
					mld_link->fw_id, NULL,
					IWL_MAX_TID_COUNT);
}

static void iwl_mld_remove_internal_sta(struct iwl_mld *mld,
					struct iwl_mld_int_sta *internal_sta,
					bool flush, u8 tid)
{
	if (WARN_ON_ONCE(internal_sta->sta_id == IWL_INVALID_STA ||
			 internal_sta->queue_id == IWL_MLD_INVALID_QUEUE))
		return;

	if (flush)
		iwl_mld_flush_link_sta_txqs(mld, internal_sta->sta_id);

	iwl_mld_free_txq(mld, BIT(internal_sta->sta_id),
			 tid, internal_sta->queue_id);

	iwl_mld_rm_sta_from_fw(mld, internal_sta->sta_id);

	iwl_mld_free_internal_sta(mld, internal_sta);
}

void iwl_mld_remove_bcast_sta(struct iwl_mld *mld,
			      struct ieee80211_vif *vif,
			      struct ieee80211_bss_conf *link)
{
	struct iwl_mld_link *mld_link = iwl_mld_link_from_mac80211(link);

	if (WARN_ON(!mld_link))
		return;

	if (WARN_ON(vif->type != NL80211_IFTYPE_AP &&
		    vif->type != NL80211_IFTYPE_ADHOC))
		return;

	iwl_mld_remove_internal_sta(mld, &mld_link->bcast_sta, true,
				    IWL_MGMT_TID);
}

void iwl_mld_remove_mcast_sta(struct iwl_mld *mld,
			      struct ieee80211_vif *vif,
			      struct ieee80211_bss_conf *link)
{
	struct iwl_mld_link *mld_link = iwl_mld_link_from_mac80211(link);

	if (WARN_ON(!mld_link))
		return;

	if (WARN_ON(vif->type != NL80211_IFTYPE_AP &&
		    vif->type != NL80211_IFTYPE_ADHOC))
		return;

	iwl_mld_remove_internal_sta(mld, &mld_link->mcast_sta, true, 0);
}

void iwl_mld_remove_aux_sta(struct iwl_mld *mld,
			    struct ieee80211_vif *vif)
{
	struct iwl_mld_vif *mld_vif = iwl_mld_vif_from_mac80211(vif);

	if (WARN_ON(vif->type != NL80211_IFTYPE_P2P_DEVICE &&
		    vif->type != NL80211_IFTYPE_STATION))
		return;

	iwl_mld_remove_internal_sta(mld, &mld_vif->aux_sta, false,
				    IWL_MAX_TID_COUNT);
}

void iwl_mld_remove_mon_sta(struct iwl_mld *mld,
			    struct ieee80211_vif *vif,
			    struct ieee80211_bss_conf *link)
{
	struct iwl_mld_link *mld_link = iwl_mld_link_from_mac80211(link);

	if (WARN_ON(!mld_link))
		return;

	if (WARN_ON(vif->type != NL80211_IFTYPE_MONITOR))
		return;

	iwl_mld_remove_internal_sta(mld, &mld_link->mon_sta, false,
				    IWL_MAX_TID_COUNT);
}

static int iwl_mld_update_sta_resources(struct iwl_mld *mld,
					struct ieee80211_vif *vif,
					struct ieee80211_sta *sta,
					u32 old_sta_mask,
					u32 new_sta_mask)
{
	int ret;

	ret = iwl_mld_update_sta_txqs(mld, sta, old_sta_mask, new_sta_mask);
	if (ret)
		return ret;

	ret = iwl_mld_update_sta_keys(mld, vif, sta, old_sta_mask, new_sta_mask);
	if (ret)
		return ret;

	return iwl_mld_update_sta_baids(mld, old_sta_mask, new_sta_mask);
}

int iwl_mld_update_link_stas(struct iwl_mld *mld,
			     struct ieee80211_vif *vif,
			     struct ieee80211_sta *sta,
			     u16 old_links, u16 new_links)
{
	struct iwl_mld_sta *mld_sta = iwl_mld_sta_from_mac80211(sta);
	struct iwl_mld_link_sta *mld_link_sta;
	unsigned long links_to_add = ~old_links & new_links;
	unsigned long links_to_rem = old_links & ~new_links;
	unsigned long old_links_long = old_links;
	unsigned long sta_mask_added = 0;
	u32 current_sta_mask = 0, sta_mask_to_rem = 0;
	unsigned int link_id, sta_id;
	int ret;

	lockdep_assert_wiphy(mld->wiphy);

	for_each_set_bit(link_id, &old_links_long,
			 IEEE80211_MLD_MAX_NUM_LINKS) {
		mld_link_sta =
			iwl_mld_link_sta_dereference_check(mld_sta, link_id);

		if (WARN_ON(!mld_link_sta))
			return -EINVAL;

		current_sta_mask |= BIT(mld_link_sta->fw_id);
		if (links_to_rem & BIT(link_id))
			sta_mask_to_rem |= BIT(mld_link_sta->fw_id);
	}

	if (sta_mask_to_rem) {
		ret = iwl_mld_update_sta_resources(mld, vif, sta,
						   current_sta_mask,
						   current_sta_mask &
							~sta_mask_to_rem);
		if (ret)
			return ret;

		current_sta_mask &= ~sta_mask_to_rem;
	}

	for_each_set_bit(link_id, &links_to_rem, IEEE80211_MLD_MAX_NUM_LINKS) {
		struct ieee80211_link_sta *link_sta =
			link_sta_dereference_protected(sta, link_id);

		if (WARN_ON(!link_sta))
			return -EINVAL;

		iwl_mld_remove_link_sta(mld, link_sta);
	}

	for_each_set_bit(link_id, &links_to_add, IEEE80211_MLD_MAX_NUM_LINKS) {
		struct ieee80211_link_sta *link_sta =
			link_sta_dereference_protected(sta, link_id);
		struct ieee80211_bss_conf *link;

		if (WARN_ON(!link_sta))
			return -EINVAL;

		ret = iwl_mld_add_link_sta(mld, link_sta);
		if (ret)
			goto remove_added_link_stas;

		mld_link_sta =
			iwl_mld_link_sta_dereference_check(mld_sta,
							   link_id);

		link = link_conf_dereference_protected(mld_sta->vif,
						       link_sta->link_id);

		iwl_mld_set_max_amsdu_len(mld, link_sta);
		iwl_mld_config_tlc_link(mld, vif, link, link_sta);

		sta_mask_added |= BIT(mld_link_sta->fw_id);
	}

	if (sta_mask_added) {
		ret = iwl_mld_update_sta_resources(mld, vif, sta,
						   current_sta_mask,
						   current_sta_mask |
							sta_mask_added);
		if (ret)
			goto remove_added_link_stas;
	}

	/* We couldn't activate the links before it has a STA. Now we can */
	for_each_set_bit(link_id, &links_to_add, IEEE80211_MLD_MAX_NUM_LINKS) {
		struct ieee80211_bss_conf *link =
			link_conf_dereference_protected(mld_sta->vif, link_id);

		if (WARN_ON(!link))
			continue;

		iwl_mld_activate_link(mld, link);
	}

	return 0;

remove_added_link_stas:
	for_each_set_bit(sta_id, &sta_mask_added, mld->fw->ucode_capa.num_stations) {
		struct ieee80211_link_sta *link_sta =
			wiphy_dereference(mld->wiphy,
					  mld->fw_id_to_link_sta[sta_id]);

		if (WARN_ON(!link_sta))
			continue;

		iwl_mld_remove_link_sta(mld, link_sta);
	}

	return ret;
}