[PATCH 0/4] mac80211: define VHT rate mask logic

[PATCH 0/4] mac80211: define VHT rate mask logic

[Lorenzo Bianconi]

Add support to mask vht rates using ratemask configured by the user through
iw command (e.g. iw dev wlan0 set bitrates vht-mcs-5 2:2,4).
Remove ieee80211_tx_rate dependency in rate mask code in order to use
mcs/legacy rate mask logic for station rate table as well.
This patchset has been tested using mac80211/mt76 driver on
Buffalo WHR-1166D router running OpenWrt trunk

Lorenzo Bianconi (4):
  mac80211: remove ieee80211_tx_info from rate_control_apply_mask
    signature
  mac80211: remove ieee80211_tx_rate dependency in rate mask code
  mac80211: define rate_control_apply_mask_ratetbl()
  mac80211: add rate mask logic for vht rates

 net/mac80211/cfg.c            |  16 ++-
 net/mac80211/debugfs_netdev.c |  34 ++++++
 net/mac80211/ieee80211_i.h    |   5 +
 net/mac80211/iface.c          |  14 ++-
 net/mac80211/rate.c           | 251 ++++++++++++++++++++++++++++++------------
 net/mac80211/vht.c            |  27 +++++
 6 files changed, 271 insertions(+), 76 deletions(-)

-- 
2.1.4

[PATCH 1/4] mac80211: remove ieee80211_tx_info from rate_control_apply_mask signature

[Lorenzo Bianconi]

Remove unnecessary ieee80211_tx_info pointer from rate_control_apply_mask
signature. rate_control_apply_mask() will be used to define a ratemask in
rate_control_set_rates() for station rate table

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
---
 net/mac80211/rate.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 03687d2..4f02e07 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -631,7 +631,6 @@ static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 				    struct ieee80211_sta *sta,
 				    struct ieee80211_supported_band *sband,
-				    struct ieee80211_tx_info *info,
 				    struct ieee80211_tx_rate *rates,
 				    int max_rates)
 {
@@ -647,8 +646,8 @@ static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 	 * default mask (allow all rates) is used to save some processing for
 	 * the common case.
 	 */
-	mask = sdata->rc_rateidx_mask[info->band];
-	has_mcs_mask = sdata->rc_has_mcs_mask[info->band];
+	mask = sdata->rc_rateidx_mask[sband->band];
+	has_mcs_mask = sdata->rc_has_mcs_mask[sband->band];
 	rate_flags =
 		ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
 	for (i = 0; i < sband->n_bitrates; i++)
@@ -659,14 +658,14 @@ static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 		return;
 
 	if (has_mcs_mask)
-		memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
+		memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 		       sizeof(mcs_mask));
 	else
 		memset(mcs_mask, 0xff, sizeof(mcs_mask));
 
 	if (sta) {
 		/* Filter out rates that the STA does not support */
-		mask &= sta->supp_rates[info->band];
+		mask &= sta->supp_rates[sband->band];
 		for (i = 0; i < sizeof(mcs_mask); i++)
 			mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
 	}
@@ -707,7 +706,7 @@ void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 	sband = sdata->local->hw.wiphy->bands[info->band];
 
 	if (ieee80211_is_data(hdr->frame_control))
-		rate_control_apply_mask(sdata, sta, sband, info, dest, max_rates);
+		rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 
 	if (dest[0].idx < 0)
 		__rate_control_send_low(&sdata->local->hw, sband, sta, info,
-- 
2.1.4

[PATCH 2/4] mac80211: remove ieee80211_tx_rate dependency in rate mask code

[Lorenzo Bianconi]

Remove ieee80211_tx_rate dependency in rate_idx_match_legacy_mask(),
rate_idx_match_mcs_mask() and rate_idx_match_mask() in order to use the
previous logic to define a ratemask in rate_control_set_rates() for
station rate table. Moreover move rate mask definition logic in
rate_control_cap_mask()

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
---
 net/mac80211/rate.c | 139 +++++++++++++++++++++++++++-------------------------
 1 file changed, 71 insertions(+), 68 deletions(-)

diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 4f02e07..4f61ca0 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -353,39 +353,37 @@ bool rate_control_send_low(struct ieee80211_sta *pubsta,
 }
 EXPORT_SYMBOL(rate_control_send_low);
 
-static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
-				       int n_bitrates, u32 mask)
+static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 {
 	int j;
 
 	/* See whether the selected rate or anything below it is allowed. */
-	for (j = rate->idx; j >= 0; j--) {
+	for (j = *rate_idx; j >= 0; j--) {
 		if (mask & (1 << j)) {
 			/* Okay, found a suitable rate. Use it. */
-			rate->idx = j;
+			*rate_idx = j;
 			return true;
 		}
 	}
 
 	/* Try to find a higher rate that would be allowed */
-	for (j = rate->idx + 1; j < n_bitrates; j++) {
+	for (j = *rate_idx + 1; j < n_bitrates; j++) {
 		if (mask & (1 << j)) {
 			/* Okay, found a suitable rate. Use it. */
-			rate->idx = j;
+			*rate_idx = j;
 			return true;
 		}
 	}
 	return false;
 }
 
-static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
-				    u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
+static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 {
 	int i, j;
 	int ridx, rbit;
 
-	ridx = rate->idx / 8;
-	rbit = rate->idx % 8;
+	ridx = *rate_idx / 8;
+	rbit = *rate_idx % 8;
 
 	/* sanity check */
 	if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
@@ -395,20 +393,20 @@ static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
 	for (i = ridx; i >= 0; i--) {
 		for (j = rbit; j >= 0; j--)
 			if (mcs_mask[i] & BIT(j)) {
-				rate->idx = i * 8 + j;
+				*rate_idx = i * 8 + j;
 				return true;
 			}
 		rbit = 7;
 	}
 
 	/* Try to find a higher rate that would be allowed */
-	ridx = (rate->idx + 1) / 8;
-	rbit = (rate->idx + 1) % 8;
+	ridx = (*rate_idx + 1) / 8;
+	rbit = (*rate_idx + 1) % 8;
 
 	for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 		for (j = rbit; j < 8; j++)
 			if (mcs_mask[i] & BIT(j)) {
-				rate->idx = i * 8 + j;
+				*rate_idx = i * 8 + j;
 				return true;
 			}
 		rbit = 0;
@@ -418,35 +416,30 @@ static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
 
 
 
-static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
+static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 				struct ieee80211_supported_band *sband,
 				enum nl80211_chan_width chan_width,
 				u32 mask,
 				u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
 {
-	struct ieee80211_tx_rate alt_rate;
-
 	/* handle HT rates */
-	if (rate->flags & IEEE80211_TX_RC_MCS) {
-		if (rate_idx_match_mcs_mask(rate, mcs_mask))
+	if (*rate_flags & IEEE80211_TX_RC_MCS) {
+		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 			return;
 
 		/* also try the legacy rates. */
-		alt_rate.idx = 0;
+		*rate_idx = 0;
 		/* keep protection flags */
-		alt_rate.flags = rate->flags &
-				 (IEEE80211_TX_RC_USE_RTS_CTS |
-				  IEEE80211_TX_RC_USE_CTS_PROTECT |
-				  IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
-		alt_rate.count = rate->count;
-		if (rate_idx_match_legacy_mask(&alt_rate,
-					       sband->n_bitrates, mask)) {
-			*rate = alt_rate;
+		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
+				IEEE80211_TX_RC_USE_CTS_PROTECT |
+				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
+		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
+					       mask))
 			return;
-		}
-	} else if (!(rate->flags & IEEE80211_TX_RC_VHT_MCS)) {
+	} else if (!(*rate_flags & IEEE80211_TX_RC_VHT_MCS)) {
 		/* handle legacy rates */
-		if (rate_idx_match_legacy_mask(rate, sband->n_bitrates, mask))
+		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
+					       mask))
 			return;
 
 		/* if HT BSS, and we handle a data frame, also try HT rates */
@@ -459,23 +452,19 @@ static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
 			break;
 		}
 
-		alt_rate.idx = 0;
+		*rate_idx = 0;
 		/* keep protection flags */
-		alt_rate.flags = rate->flags &
-				 (IEEE80211_TX_RC_USE_RTS_CTS |
-				  IEEE80211_TX_RC_USE_CTS_PROTECT |
-				  IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
-		alt_rate.count = rate->count;
+		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
+				IEEE80211_TX_RC_USE_CTS_PROTECT |
+				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 
-		alt_rate.flags |= IEEE80211_TX_RC_MCS;
+		*rate_flags |= IEEE80211_TX_RC_MCS;
 
 		if (chan_width == NL80211_CHAN_WIDTH_40)
-			alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
+			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 
-		if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
-			*rate = alt_rate;
+		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 			return;
-		}
 	}
 
 	/*
@@ -628,6 +617,40 @@ static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 	}
 }
 
+static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
+				  struct ieee80211_supported_band *sband,
+				  struct ieee80211_sta *sta, u32 *mask,
+				  u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
+{
+	u32 i, flags;
+
+	*mask = sdata->rc_rateidx_mask[sband->band];
+	flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
+	for (i = 0; i < sband->n_bitrates; i++) {
+		if ((flags & sband->bitrates[i].flags) != flags)
+			*mask &= ~BIT(i);
+	}
+
+	if (*mask == (1 << sband->n_bitrates) - 1 &&
+	    !sdata->rc_has_mcs_mask[sband->band])
+		return false;
+
+	if (sdata->rc_has_mcs_mask[sband->band])
+		memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
+		       IEEE80211_HT_MCS_MASK_LEN);
+	else
+		memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
+
+	if (sta) {
+		/* Filter out rates that the STA does not support */
+		*mask &= sta->supp_rates[sband->band];
+		for (i = 0; i < sizeof(mcs_mask); i++)
+			mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
+	}
+
+	return true;
+}
+
 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 				    struct ieee80211_sta *sta,
 				    struct ieee80211_supported_band *sband,
@@ -636,9 +659,8 @@ static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 {
 	enum nl80211_chan_width chan_width;
 	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
-	bool has_mcs_mask;
 	u32 mask;
-	u32 rate_flags;
+	u16 rate_flags;
 	int i;
 
 	/*
@@ -646,30 +668,9 @@ static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 	 * default mask (allow all rates) is used to save some processing for
 	 * the common case.
 	 */
-	mask = sdata->rc_rateidx_mask[sband->band];
-	has_mcs_mask = sdata->rc_has_mcs_mask[sband->band];
-	rate_flags =
-		ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
-	for (i = 0; i < sband->n_bitrates; i++)
-		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
-			mask &= ~BIT(i);
-
-	if (mask == (1 << sband->n_bitrates) - 1 && !has_mcs_mask)
+	if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask))
 		return;
 
-	if (has_mcs_mask)
-		memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
-		       sizeof(mcs_mask));
-	else
-		memset(mcs_mask, 0xff, sizeof(mcs_mask));
-
-	if (sta) {
-		/* Filter out rates that the STA does not support */
-		mask &= sta->supp_rates[sband->band];
-		for (i = 0; i < sizeof(mcs_mask); i++)
-			mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
-	}
-
 	/*
 	 * Make sure the rate index selected for each TX rate is
 	 * included in the configured mask and change the rate indexes
@@ -681,8 +682,10 @@ static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 		if (rates[i].idx < 0)
 			break;
 
-		rate_idx_match_mask(&rates[i], sband, chan_width, mask,
-				    mcs_mask);
+		rate_flags = rates[i].flags;
+		rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
+				    chan_width, mask, mcs_mask);
+		rates[i].flags = rate_flags;
 	}
 }
 
-- 
2.1.4

[PATCH 3/4] mac80211: define rate_control_apply_mask_ratetbl()

[Lorenzo Bianconi]

Define rate_control_apply_mask_ratetbl() in order to apply ratemask in
rate_control_set_rates() for station rate table

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
---
 net/mac80211/rate.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 4f61ca0..7e71de9 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -651,6 +651,30 @@ static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 	return true;
 }
 
+static void
+rate_control_apply_mask_ratetbl(struct sta_info *sta,
+				struct ieee80211_supported_band *sband,
+				struct ieee80211_sta_rates *rates)
+{
+	int i;
+	u32 mask;
+	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
+	enum nl80211_chan_width chan_width;
+
+	if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
+				   mcs_mask))
+		return;
+
+	chan_width = sta->sdata->vif.bss_conf.chandef.width;
+	for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
+		if (rates->rate[i].idx < 0)
+			break;
+
+		rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
+				    sband, chan_width, mask, mcs_mask);
+	}
+}
+
 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 				    struct ieee80211_sta *sta,
 				    struct ieee80211_supported_band *sband,
@@ -766,7 +790,10 @@ int rate_control_set_rates(struct ieee80211_hw *hw,
 {
 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 	struct ieee80211_sta_rates *old;
+	struct ieee80211_supported_band *sband;
 
+	sband = hw->wiphy->bands[ieee80211_get_sdata_band(sta->sdata)];
+	rate_control_apply_mask_ratetbl(sta, sband, rates);
 	/*
 	 * mac80211 guarantees that this function will not be called
 	 * concurrently, so the following RCU access is safe, even without
-- 
2.1.4

[PATCH 4/4] mac80211: add rate mask logic for vht rates

[Lorenzo Bianconi]

Define rc_rateidx_vht_mcs_mask array and rate_idx_match_vht_mcs_mask()
method in order to apply mcs mask for vht rates

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
---
 net/mac80211/cfg.c            |  16 +++++--
 net/mac80211/debugfs_netdev.c |  34 ++++++++++++++
 net/mac80211/ieee80211_i.h    |   5 +++
 net/mac80211/iface.c          |  14 +++++-
 net/mac80211/rate.c           | 102 +++++++++++++++++++++++++++++++++++++-----
 net/mac80211/vht.c            |  27 +++++++++++
 6 files changed, 182 insertions(+), 16 deletions(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 5789d83..685ec13 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2504,16 +2504,26 @@ static int ieee80211_set_bitrate_mask(struct wiphy *wiphy,
 		sdata->rc_rateidx_mask[i] = mask->control[i].legacy;
 		memcpy(sdata->rc_rateidx_mcs_mask[i], mask->control[i].ht_mcs,
 		       sizeof(mask->control[i].ht_mcs));
+		memcpy(sdata->rc_rateidx_vht_mcs_mask[i],
+		       mask->control[i].vht_mcs,
+		       sizeof(mask->control[i].vht_mcs));
 
 		sdata->rc_has_mcs_mask[i] = false;
+		sdata->rc_has_vht_mcs_mask[i] = false;
 		if (!sband)
 			continue;
 
-		for (j = 0; j < IEEE80211_HT_MCS_MASK_LEN; j++)
-			if (~sdata->rc_rateidx_mcs_mask[i][j]) {
+		for (j = 0; j < IEEE80211_HT_MCS_MASK_LEN; j++) {
+			if (~sdata->rc_rateidx_mcs_mask[i][j])
 				sdata->rc_has_mcs_mask[i] = true;
+
+			if (~sdata->rc_rateidx_vht_mcs_mask[i][j])
+				sdata->rc_has_vht_mcs_mask[i] = true;
+
+			if (sdata->rc_has_mcs_mask[i] &&
+			    sdata->rc_has_vht_mcs_mask[i])
 				break;
-			}
+		}
 	}
 
 	return 0;
diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index c09c013..1021e87 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -186,6 +186,38 @@ IEEE80211_IF_FILE(rc_rateidx_mcs_mask_2ghz,
 IEEE80211_IF_FILE(rc_rateidx_mcs_mask_5ghz,
 		  rc_rateidx_mcs_mask[IEEE80211_BAND_5GHZ], HEXARRAY);
 
+static ssize_t ieee80211_if_fmt_rc_rateidx_vht_mcs_mask_2ghz(
+				const struct ieee80211_sub_if_data *sdata,
+				char *buf, int buflen)
+{
+	int i, len = 0;
+	const u16 *mask = sdata->rc_rateidx_vht_mcs_mask[IEEE80211_BAND_2GHZ];
+
+	for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
+		len += scnprintf(buf + len, buflen - len, "%04x ", mask[i]);
+	len += scnprintf(buf + len, buflen - len, "\n");
+
+	return len;
+}
+
+IEEE80211_IF_FILE_R(rc_rateidx_vht_mcs_mask_2ghz);
+
+static ssize_t ieee80211_if_fmt_rc_rateidx_vht_mcs_mask_5ghz(
+				const struct ieee80211_sub_if_data *sdata,
+				char *buf, int buflen)
+{
+	int i, len = 0;
+	const u16 *mask = sdata->rc_rateidx_vht_mcs_mask[IEEE80211_BAND_5GHZ];
+
+	for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
+		len += scnprintf(buf + len, buflen - len, "%04x ", mask[i]);
+	len += scnprintf(buf + len, buflen - len, "\n");
+
+	return len;
+}
+
+IEEE80211_IF_FILE_R(rc_rateidx_vht_mcs_mask_5ghz);
+
 IEEE80211_IF_FILE(flags, flags, HEX);
 IEEE80211_IF_FILE(state, state, LHEX);
 IEEE80211_IF_FILE(txpower, vif.bss_conf.txpower, DEC);
@@ -565,6 +597,8 @@ static void add_common_files(struct ieee80211_sub_if_data *sdata)
 	DEBUGFS_ADD(rc_rateidx_mask_5ghz);
 	DEBUGFS_ADD(rc_rateidx_mcs_mask_2ghz);
 	DEBUGFS_ADD(rc_rateidx_mcs_mask_5ghz);
+	DEBUGFS_ADD(rc_rateidx_vht_mcs_mask_2ghz);
+	DEBUGFS_ADD(rc_rateidx_vht_mcs_mask_5ghz);
 	DEBUGFS_ADD(hw_queues);
 }
 
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 36f217e..6e52659 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -901,6 +901,9 @@ struct ieee80211_sub_if_data {
 	bool rc_has_mcs_mask[IEEE80211_NUM_BANDS];
 	u8  rc_rateidx_mcs_mask[IEEE80211_NUM_BANDS][IEEE80211_HT_MCS_MASK_LEN];
 
+	bool rc_has_vht_mcs_mask[IEEE80211_NUM_BANDS];
+	u16 rc_rateidx_vht_mcs_mask[IEEE80211_NUM_BANDS][NL80211_VHT_NSS_MAX];
+
 	union {
 		struct ieee80211_if_ap ap;
 		struct ieee80211_if_wds wds;
@@ -1713,6 +1716,8 @@ void ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
 				 enum ieee80211_band band, bool nss_only);
 void ieee80211_apply_vhtcap_overrides(struct ieee80211_sub_if_data *sdata,
 				      struct ieee80211_sta_vht_cap *vht_cap);
+void ieee80211_get_vht_mask_from_cap(__le16 vht_cap,
+				     u16 vht_mask[NL80211_VHT_NSS_MAX]);
 
 /* Spectrum management */
 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 0fba7f9..6964fc6 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1788,13 +1788,23 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 		sband = local->hw.wiphy->bands[i];
 		sdata->rc_rateidx_mask[i] =
 			sband ? (1 << sband->n_bitrates) - 1 : 0;
-		if (sband)
+		if (sband) {
+			__le16 cap;
+			u16 *vht_rate_mask;
+
 			memcpy(sdata->rc_rateidx_mcs_mask[i],
 			       sband->ht_cap.mcs.rx_mask,
 			       sizeof(sdata->rc_rateidx_mcs_mask[i]));
-		else
+
+			cap = sband->vht_cap.vht_mcs.rx_mcs_map;
+			vht_rate_mask = sdata->rc_rateidx_vht_mcs_mask[i];
+			ieee80211_get_vht_mask_from_cap(cap, vht_rate_mask);
+		} else {
 			memset(sdata->rc_rateidx_mcs_mask[i], 0,
 			       sizeof(sdata->rc_rateidx_mcs_mask[i]));
+			memset(sdata->rc_rateidx_vht_mcs_mask[i], 0,
+			       sizeof(sdata->rc_rateidx_vht_mcs_mask[i]));
+		}
 	}
 
 	ieee80211_set_default_queues(sdata);
diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 7e71de9..9857693 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -414,16 +414,77 @@ static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 	return false;
 }
 
+static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
+{
+	int i, j;
+	int ridx, rbit;
+
+	ridx = *rate_idx >> 4;
+	rbit = *rate_idx & 0xf;
+
+	if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
+		return false;
 
+	/* See whether the selected rate or anything below it is allowed. */
+	for (i = ridx; i >= 0; i--) {
+		for (j = rbit; j >= 0; j--) {
+			if (vht_mask[i] & BIT(j)) {
+				*rate_idx = (i << 4) | j;
+				return true;
+			}
+		}
+		rbit = 15;
+	}
+
+	/* Try to find a higher rate that would be allowed */
+	ridx = (*rate_idx + 1) >> 4;
+	rbit = (*rate_idx + 1) & 0xf;
+
+	for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
+		for (j = rbit; j < 16; j++) {
+			if (vht_mask[i] & BIT(j)) {
+				*rate_idx = (i << 4) | j;
+				return true;
+			}
+		}
+		rbit = 0;
+	}
+	return false;
+}
 
 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 				struct ieee80211_supported_band *sband,
 				enum nl80211_chan_width chan_width,
 				u32 mask,
-				u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
+				u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
+				u16 vht_mask[NL80211_VHT_NSS_MAX])
 {
-	/* handle HT rates */
-	if (*rate_flags & IEEE80211_TX_RC_MCS) {
+	if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
+		/* handle VHT rates */
+		if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
+			return;
+
+		*rate_idx = 0;
+		/* keep protection flags */
+		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
+				IEEE80211_TX_RC_USE_CTS_PROTECT |
+				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
+
+		*rate_flags |= IEEE80211_TX_RC_MCS;
+		if (chan_width == NL80211_CHAN_WIDTH_40)
+			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
+
+		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
+			return;
+
+		/* also try the legacy rates. */
+		*rate_flags &= ~(IEEE80211_TX_RC_MCS |
+				 IEEE80211_TX_RC_40_MHZ_WIDTH);
+		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
+					       mask))
+			return;
+	} else if (*rate_flags & IEEE80211_TX_RC_MCS) {
+		/* handle HT rates */
 		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 			return;
 
@@ -436,7 +497,7 @@ static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 					       mask))
 			return;
-	} else if (!(*rate_flags & IEEE80211_TX_RC_VHT_MCS)) {
+	} else {
 		/* handle legacy rates */
 		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 					       mask))
@@ -620,7 +681,8 @@ static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 				  struct ieee80211_supported_band *sband,
 				  struct ieee80211_sta *sta, u32 *mask,
-				  u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
+				  u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
+				  u16 vht_mask[NL80211_VHT_NSS_MAX])
 {
 	u32 i, flags;
 
@@ -632,7 +694,8 @@ static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 	}
 
 	if (*mask == (1 << sband->n_bitrates) - 1 &&
-	    !sdata->rc_has_mcs_mask[sband->band])
+	    !sdata->rc_has_mcs_mask[sband->band] &&
+	    !sdata->rc_has_vht_mcs_mask[sband->band])
 		return false;
 
 	if (sdata->rc_has_mcs_mask[sband->band])
@@ -641,11 +704,25 @@ static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 	else
 		memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 
+	if (sdata->rc_has_vht_mcs_mask[sband->band])
+		memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
+		       sizeof(u16) * NL80211_VHT_NSS_MAX);
+	else
+		memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
+
 	if (sta) {
+		__le16 sta_vht_cap;
+		u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
+
 		/* Filter out rates that the STA does not support */
 		*mask &= sta->supp_rates[sband->band];
 		for (i = 0; i < sizeof(mcs_mask); i++)
 			mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
+
+		sta_vht_cap = sta->vht_cap.vht_mcs.rx_mcs_map;
+		ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
+		for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
+			vht_mask[i] &= sta_vht_mask[i];
 	}
 
 	return true;
@@ -659,10 +736,11 @@ rate_control_apply_mask_ratetbl(struct sta_info *sta,
 	int i;
 	u32 mask;
 	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
+	u16 vht_mask[NL80211_VHT_NSS_MAX];
 	enum nl80211_chan_width chan_width;
 
 	if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
-				   mcs_mask))
+				   mcs_mask, vht_mask))
 		return;
 
 	chan_width = sta->sdata->vif.bss_conf.chandef.width;
@@ -671,7 +749,8 @@ rate_control_apply_mask_ratetbl(struct sta_info *sta,
 			break;
 
 		rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
-				    sband, chan_width, mask, mcs_mask);
+				    sband, chan_width, mask, mcs_mask,
+				    vht_mask);
 	}
 }
 
@@ -684,7 +763,7 @@ static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 	enum nl80211_chan_width chan_width;
 	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 	u32 mask;
-	u16 rate_flags;
+	u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 	int i;
 
 	/*
@@ -692,7 +771,8 @@ static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 	 * default mask (allow all rates) is used to save some processing for
 	 * the common case.
 	 */
-	if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask))
+	if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
+				   vht_mask))
 		return;
 
 	/*
@@ -708,7 +788,7 @@ static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 
 		rate_flags = rates[i].flags;
 		rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
-				    chan_width, mask, mcs_mask);
+				    chan_width, mask, mcs_mask, vht_mask);
 		rates[i].flags = rate_flags;
 	}
 }
diff --git a/net/mac80211/vht.c b/net/mac80211/vht.c
index f05808d..cfe583a 100644
--- a/net/mac80211/vht.c
+++ b/net/mac80211/vht.c
@@ -426,3 +426,30 @@ void ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
 	if (changed > 0)
 		rate_control_rate_update(local, sband, 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;
+		}
+	}
+}
+
-- 
2.1.4

Re: [PATCH 0/4] mac80211: define VHT rate mask logic

[Johannes Berg]

On Thu, 2015-08-06 at 23:47 +0200, Lorenzo Bianconi wrote:
> Add support to mask vht rates using ratemask configured by the user 
> through
> iw command (e.g. iw dev wlan0 set bitrates vht-mcs-5 2:2,4).
> Remove ieee80211_tx_rate dependency in rate mask code in order to use
> mcs/legacy rate mask logic for station rate table as well.
> This patchset has been tested using mac80211/mt76 driver on
> Buffalo WHR-1166D router running OpenWrt trunk
> 

All four applied.

johannes