ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 494 insertions, 0 deletions

diff --git a/net/mac80211/vht.c b/net/mac80211/vht.c
new file mode 100644
index 000000000..92a4e0450
--- /dev/null
+++ b/net/mac80211/vht.c
@@ -0,0 +1,494 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VHT handling
+ *
+ * Portions of this file
+ * Copyright(c) 2015 - 2016 Intel Deutschland GmbH
+ * Copyright (C) 2018 - 2026 Intel Corporation
+ */
+
+#include <linux/ieee80211.h>
+#include <linux/export.h>
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+#include "rate.h"
+
+
+static void __check_vhtcap_disable(struct ieee80211_sub_if_data *sdata,
+				   struct ieee80211_sta_vht_cap *vht_cap,
+				   u32 flag)
+{
+	__le32 le_flag = cpu_to_le32(flag);
+
+	if (sdata->u.mgd.vht_capa_mask.vht_cap_info & le_flag &&
+	    !(sdata->u.mgd.vht_capa.vht_cap_info & le_flag))
+		vht_cap->cap &= ~flag;
+}
+
+void ieee80211_apply_vhtcap_overrides(struct ieee80211_sub_if_data *sdata,
+				      struct ieee80211_sta_vht_cap *vht_cap)
+{
+	int i;
+	u16 rxmcs_mask, rxmcs_cap, rxmcs_n, txmcs_mask, txmcs_cap, txmcs_n;
+
+	if (!vht_cap->vht_supported)
+		return;
+
+	if (sdata->vif.type != NL80211_IFTYPE_STATION)
+		return;
+
+	__check_vhtcap_disable(sdata, vht_cap,
+			       IEEE80211_VHT_CAP_RXLDPC);
+	__check_vhtcap_disable(sdata, vht_cap,
+			       IEEE80211_VHT_CAP_SHORT_GI_80);
+	__check_vhtcap_disable(sdata, vht_cap,
+			       IEEE80211_VHT_CAP_SHORT_GI_160);
+	__check_vhtcap_disable(sdata, vht_cap,
+			       IEEE80211_VHT_CAP_TXSTBC);
+	__check_vhtcap_disable(sdata, vht_cap,
+			       IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE);
+	__check_vhtcap_disable(sdata, vht_cap,
+			       IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE);
+	__check_vhtcap_disable(sdata, vht_cap,
+			       IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN);
+	__check_vhtcap_disable(sdata, vht_cap,
+			       IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN);
+
+	/* Allow user to decrease AMPDU length exponent */
+	if (sdata->u.mgd.vht_capa_mask.vht_cap_info &
+	    cpu_to_le32(IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK)) {
+		u32 cap, n;
+
+		n = le32_to_cpu(sdata->u.mgd.vht_capa.vht_cap_info) &
+			IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
+		n >>= IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
+		cap = vht_cap->cap & IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
+		cap >>= IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
+
+		if (n < cap) {
+			vht_cap->cap &=
+				~IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
+			vht_cap->cap |=
+				n << IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
+		}
+	}
+
+	/* Allow the user to decrease MCSes */
+	rxmcs_mask =
+		le16_to_cpu(sdata->u.mgd.vht_capa_mask.supp_mcs.rx_mcs_map);
+	rxmcs_n = le16_to_cpu(sdata->u.mgd.vht_capa.supp_mcs.rx_mcs_map);
+	rxmcs_n &= rxmcs_mask;
+	rxmcs_cap = le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
+
+	txmcs_mask =
+		le16_to_cpu(sdata->u.mgd.vht_capa_mask.supp_mcs.tx_mcs_map);
+	txmcs_n = le16_to_cpu(sdata->u.mgd.vht_capa.supp_mcs.tx_mcs_map);
+	txmcs_n &= txmcs_mask;
+	txmcs_cap = le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
+	for (i = 0; i < 8; i++) {
+		u8 m, n, c;
+
+		m = (rxmcs_mask >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+		n = (rxmcs_n >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+		c = (rxmcs_cap >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		if (m && ((c != IEEE80211_VHT_MCS_NOT_SUPPORTED && n < c) ||
+			  n == IEEE80211_VHT_MCS_NOT_SUPPORTED)) {
+			rxmcs_cap &= ~(3 << 2*i);
+			rxmcs_cap |= (rxmcs_n & (3 << 2*i));
+		}
+
+		m = (txmcs_mask >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+		n = (txmcs_n >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+		c = (txmcs_cap >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		if (m && ((c != IEEE80211_VHT_MCS_NOT_SUPPORTED && n < c) ||
+			  n == IEEE80211_VHT_MCS_NOT_SUPPORTED)) {
+			txmcs_cap &= ~(3 << 2*i);
+			txmcs_cap |= (txmcs_n & (3 << 2*i));
+		}
+	}
+	vht_cap->vht_mcs.rx_mcs_map = cpu_to_le16(rxmcs_cap);
+	vht_cap->vht_mcs.tx_mcs_map = cpu_to_le16(txmcs_cap);
+}
+
+void
+ieee80211_vht_cap_ie_to_sta_vht_cap(struct ieee80211_sub_if_data *sdata,
+				    struct ieee80211_supported_band *sband,
+				    const struct ieee80211_sta_vht_cap *own_vht_cap,
+				    const struct ieee80211_vht_cap *vht_cap_ie,
+				    const struct ieee80211_vht_cap *vht_cap_ie2,
+				    struct link_sta_info *link_sta)
+{
+	struct ieee80211_sta_vht_cap *vht_cap = &link_sta->pub->vht_cap;
+	struct ieee80211_sta_vht_cap own_cap;
+	u32 cap_info, i;
+	u32 mpdu_len;
+
+	memset(vht_cap, 0, sizeof(*vht_cap));
+
+	if (!link_sta->pub->ht_cap.ht_supported)
+		return;
+
+	if (!vht_cap_ie || !own_vht_cap->vht_supported)
+		return;
+
+	/* NDI station are using the capabilities from the NMI station */
+	if (WARN_ON_ONCE(sdata->vif.type == NL80211_IFTYPE_NAN_DATA))
+		return;
+
+	if (sband) {
+		/* Allow VHT if at least one channel on the sband supports 80 MHz */
+		bool have_80mhz = false;
+
+		for (i = 0; i < sband->n_channels; i++) {
+			if (sband->channels[i].flags & (IEEE80211_CHAN_DISABLED |
+							IEEE80211_CHAN_NO_80MHZ))
+				continue;
+
+			have_80mhz = true;
+			break;
+		}
+
+		if (!have_80mhz)
+			return;
+	}
+
+	/*
+	 * A VHT STA must support 40 MHz, but if we verify that here
+	 * then we break a few things - some APs (e.g. Netgear R6300v2
+	 * and others based on the BCM4360 chipset) will unset this
+	 * capability bit when operating in 20 MHz.
+	 */
+
+	vht_cap->vht_supported = true;
+
+	own_cap = *own_vht_cap;
+	/*
+	 * If user has specified capability overrides, take care
+	 * of that if the station we're setting up is the AP that
+	 * we advertised a restricted capability set to. Override
+	 * our own capabilities and then use those below.
+	 */
+	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+	    !test_sta_flag(link_sta->sta, WLAN_STA_TDLS_PEER))
+		ieee80211_apply_vhtcap_overrides(sdata, &own_cap);
+
+	/* take some capabilities as-is */
+	cap_info = le32_to_cpu(vht_cap_ie->vht_cap_info);
+	vht_cap->cap = cap_info;
+	vht_cap->cap &= IEEE80211_VHT_CAP_RXLDPC |
+			IEEE80211_VHT_CAP_VHT_TXOP_PS |
+			IEEE80211_VHT_CAP_HTC_VHT |
+			IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK |
+			IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_UNSOL_MFB |
+			IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB |
+			IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN |
+			IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN;
+
+	vht_cap->cap |= min_t(u32, cap_info & IEEE80211_VHT_CAP_MAX_MPDU_MASK,
+			      own_cap.cap & IEEE80211_VHT_CAP_MAX_MPDU_MASK);
+
+	/* and some based on our own capabilities */
+	switch (own_cap.cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
+	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
+		vht_cap->cap |= cap_info &
+				IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
+		break;
+	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ:
+		vht_cap->cap |= cap_info &
+				IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
+		break;
+	default:
+		/* nothing */
+		break;
+	}
+
+	/* symmetric capabilities */
+	vht_cap->cap |= cap_info & own_cap.cap &
+			(IEEE80211_VHT_CAP_SHORT_GI_80 |
+			 IEEE80211_VHT_CAP_SHORT_GI_160);
+
+	/* remaining ones */
+	if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE)
+		vht_cap->cap |= cap_info &
+				(IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE |
+				 IEEE80211_VHT_CAP_SOUNDING_DIMENSIONS_MASK);
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE)
+		vht_cap->cap |= cap_info &
+				(IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE |
+				 IEEE80211_VHT_CAP_BEAMFORMEE_STS_MASK);
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE)
+		vht_cap->cap |= cap_info &
+				IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE;
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE)
+		vht_cap->cap |= cap_info &
+				IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE;
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_TXSTBC)
+		vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_RXSTBC_MASK;
+
+	if (own_cap.cap & IEEE80211_VHT_CAP_RXSTBC_MASK)
+		vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_TXSTBC;
+
+	/* Copy peer MCS info, the driver might need them. */
+	memcpy(&vht_cap->vht_mcs, &vht_cap_ie->supp_mcs,
+	       sizeof(struct ieee80211_vht_mcs_info));
+
+	/* copy EXT_NSS_BW Support value or remove the capability */
+	if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_VHT_EXT_NSS_BW))
+		vht_cap->cap |= (cap_info & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK);
+	else
+		vht_cap->vht_mcs.tx_highest &=
+			~cpu_to_le16(IEEE80211_VHT_EXT_NSS_BW_CAPABLE);
+
+	/* but also restrict MCSes */
+	for (i = 0; i < 8; i++) {
+		u16 own_rx, own_tx, peer_rx, peer_tx;
+
+		own_rx = le16_to_cpu(own_cap.vht_mcs.rx_mcs_map);
+		own_rx = (own_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		own_tx = le16_to_cpu(own_cap.vht_mcs.tx_mcs_map);
+		own_tx = (own_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		peer_rx = le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
+		peer_rx = (peer_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		peer_tx = le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
+		peer_tx = (peer_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+
+		if (peer_tx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
+			if (own_rx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
+				peer_tx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
+			else if (own_rx < peer_tx)
+				peer_tx = own_rx;
+		}
+
+		if (peer_rx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
+			if (own_tx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
+				peer_rx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
+			else if (own_tx < peer_rx)
+				peer_rx = own_tx;
+		}
+
+		vht_cap->vht_mcs.rx_mcs_map &=
+			~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
+		vht_cap->vht_mcs.rx_mcs_map |= cpu_to_le16(peer_rx << i * 2);
+
+		vht_cap->vht_mcs.tx_mcs_map &=
+			~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
+		vht_cap->vht_mcs.tx_mcs_map |= cpu_to_le16(peer_tx << i * 2);
+	}
+
+	/*
+	 * This is a workaround for VHT-enabled STAs which break the spec
+	 * and have the VHT-MCS Rx map filled in with value 3 for all eight
+	 * spatial streams, an example is AR9462.
+	 *
+	 * As per spec, in section 22.1.1 Introduction to the VHT PHY
+	 * A VHT STA shall support at least single spatial stream VHT-MCSs
+	 * 0 to 7 (transmit and receive) in all supported channel widths.
+	 */
+	if (vht_cap->vht_mcs.rx_mcs_map == cpu_to_le16(0xFFFF)) {
+		vht_cap->vht_supported = false;
+		sdata_info(sdata,
+			   "Ignoring VHT IE from %pM (link:%pM) due to invalid rx_mcs_map\n",
+			   link_sta->sta->addr, link_sta->addr);
+		return;
+	}
+
+	/*
+	 * Work around the Cisco 9115 FW 17.3 bug by taking the min of
+	 * both reported MPDU lengths.
+	 */
+	mpdu_len = vht_cap->cap & IEEE80211_VHT_CAP_MAX_MPDU_MASK;
+	if (vht_cap_ie2)
+		mpdu_len = min_t(u32, mpdu_len,
+				 le32_get_bits(vht_cap_ie2->vht_cap_info,
+					       IEEE80211_VHT_CAP_MAX_MPDU_MASK));
+
+	/*
+	 * FIXME - should the amsdu len be per link? store per link
+	 * and maintain a minimum?
+	 */
+	switch (mpdu_len) {
+	case IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454:
+		link_sta->pub->agg.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_VHT_11454;
+		break;
+	case IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_7991:
+		link_sta->pub->agg.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_VHT_7991;
+		break;
+	case IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_3895:
+	default:
+		link_sta->pub->agg.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_VHT_3895;
+		break;
+	}
+
+	ieee80211_sta_recalc_aggregates(&link_sta->sta->sta);
+}
+
+u32 __ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
+				  struct link_sta_info *link_sta,
+				  u8 opmode, enum nl80211_band band)
+{
+	enum ieee80211_sta_rx_bandwidth new_bw;
+	struct sta_opmode_info sta_opmode = {};
+	struct ieee80211_link_data *link;
+	u32 changed = 0;
+	u8 nss;
+
+	link = sdata_dereference(sdata->link[link_sta->link_id], sdata);
+	if (WARN_ON(!link))
+		return 0;
+
+	/* ignore - no support for BF yet */
+	if (opmode & IEEE80211_OPMODE_NOTIF_RX_NSS_TYPE_BF)
+		return 0;
+
+	nss = opmode & IEEE80211_OPMODE_NOTIF_RX_NSS_MASK;
+	nss >>= IEEE80211_OPMODE_NOTIF_RX_NSS_SHIFT;
+	nss += 1;
+
+	if (link_sta->op_mode_nss != nss) {
+		if (nss <= link_sta->capa_nss) {
+			link_sta->op_mode_nss = nss;
+
+			if (nss != link_sta->pub->rx_nss) {
+				link_sta->pub->rx_nss = nss;
+				changed |= IEEE80211_RC_NSS_CHANGED;
+				sta_opmode.rx_nss = link_sta->pub->rx_nss;
+				sta_opmode.changed |= STA_OPMODE_N_SS_CHANGED;
+			}
+		} else {
+			sdata_dbg(sdata,
+				  "Ignore NSS change to invalid %d in VHT opmode notif from %pM",
+				  nss, link_sta->pub->addr);
+		}
+	}
+
+	switch (opmode & IEEE80211_OPMODE_NOTIF_CHANWIDTH_MASK) {
+	case IEEE80211_OPMODE_NOTIF_CHANWIDTH_20MHZ:
+		/* ignore IEEE80211_OPMODE_NOTIF_BW_160_80P80 must not be set */
+		link_sta->op_mode_bw = IEEE80211_STA_RX_BW_20;
+		break;
+	case IEEE80211_OPMODE_NOTIF_CHANWIDTH_40MHZ:
+		/* ignore IEEE80211_OPMODE_NOTIF_BW_160_80P80 must not be set */
+		link_sta->op_mode_bw = IEEE80211_STA_RX_BW_40;
+		break;
+	case IEEE80211_OPMODE_NOTIF_CHANWIDTH_80MHZ:
+		if (opmode & IEEE80211_OPMODE_NOTIF_BW_160_80P80)
+			link_sta->op_mode_bw = IEEE80211_STA_RX_BW_160;
+		else
+			link_sta->op_mode_bw = IEEE80211_STA_RX_BW_80;
+		break;
+	case IEEE80211_OPMODE_NOTIF_CHANWIDTH_160MHZ:
+		/* legacy only, no longer used by newer spec */
+		link_sta->op_mode_bw = IEEE80211_STA_RX_BW_160;
+		break;
+	}
+
+	new_bw = ieee80211_sta_current_bw(link_sta, &link->conf->chanreq.oper,
+					  IEEE80211_STA_BW_TX_TO_STA);
+	if (new_bw != link_sta->pub->bandwidth) {
+		link_sta->pub->bandwidth = new_bw;
+		sta_opmode.bw = ieee80211_sta_rx_bw_to_chan_width(new_bw);
+		changed |= IEEE80211_RC_BW_CHANGED;
+		sta_opmode.changed |= STA_OPMODE_MAX_BW_CHANGED;
+	}
+
+	if (sta_opmode.changed)
+		cfg80211_sta_opmode_change_notify(sdata->dev, link_sta->addr,
+						  &sta_opmode, GFP_KERNEL);
+
+	return changed;
+}
+
+void ieee80211_process_mu_groups(struct ieee80211_sub_if_data *sdata,
+				 struct ieee80211_link_data *link,
+				 struct ieee80211_mgmt *mgmt)
+{
+	struct ieee80211_bss_conf *link_conf = link->conf;
+
+	if (!link_conf->mu_mimo_owner)
+		return;
+
+	if (!memcmp(mgmt->u.action.vht_group_notif.position,
+		    link_conf->mu_group.position, WLAN_USER_POSITION_LEN) &&
+	    !memcmp(mgmt->u.action.vht_group_notif.membership,
+		    link_conf->mu_group.membership, WLAN_MEMBERSHIP_LEN))
+		return;
+
+	memcpy(link_conf->mu_group.membership,
+	       mgmt->u.action.vht_group_notif.membership,
+	       WLAN_MEMBERSHIP_LEN);
+	memcpy(link_conf->mu_group.position,
+	       mgmt->u.action.vht_group_notif.position,
+	       WLAN_USER_POSITION_LEN);
+
+	ieee80211_link_info_change_notify(sdata, link,
+					  BSS_CHANGED_MU_GROUPS);
+}
+
+void ieee80211_update_mu_groups(struct ieee80211_vif *vif, unsigned int link_id,
+				const u8 *membership, const u8 *position)
+{
+	struct ieee80211_bss_conf *link_conf;
+
+	rcu_read_lock();
+	link_conf = rcu_dereference(vif->link_conf[link_id]);
+
+	if (!WARN_ON_ONCE(!link_conf || !link_conf->mu_mimo_owner)) {
+		memcpy(link_conf->mu_group.membership, membership,
+		       WLAN_MEMBERSHIP_LEN);
+		memcpy(link_conf->mu_group.position, position,
+		       WLAN_USER_POSITION_LEN);
+	}
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(ieee80211_update_mu_groups);
+
+void ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
+				 struct link_sta_info *link_sta,
+				 u8 opmode, enum nl80211_band band)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
+
+	u32 changed = __ieee80211_vht_handle_opmode(sdata, link_sta,
+						    opmode, band);
+
+	if (changed > 0) {
+		ieee80211_recalc_min_chandef(sdata, link_sta->link_id);
+		rate_control_rate_update(local, sband, link_sta, changed);
+	}
+}
+
+void ieee80211_get_vht_mask_from_cap(__le16 vht_cap,
+				     u16 vht_mask[NL80211_VHT_NSS_MAX])
+{
+	int i;
+	u16 mask, cap = le16_to_cpu(vht_cap);
+
+	for (i = 0; i < NL80211_VHT_NSS_MAX; i++) {
+		mask = (cap >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
+		switch (mask) {
+		case IEEE80211_VHT_MCS_SUPPORT_0_7:
+			vht_mask[i] = 0x00FF;
+			break;
+		case IEEE80211_VHT_MCS_SUPPORT_0_8:
+			vht_mask[i] = 0x01FF;
+			break;
+		case IEEE80211_VHT_MCS_SUPPORT_0_9:
+			vht_mask[i] = 0x03FF;
+			break;
+		case IEEE80211_VHT_MCS_NOT_SUPPORTED:
+		default:
+			vht_mask[i] = 0;
+			break;
+		}
+	}
+}