3 files changed, 175 insertions, 50 deletions

diff --git a/drivers/net/wireless/ath/regd.c b/drivers/net/wireless/ath/regd.c
index fdf07c822081..7a89f9fac7d4 100644
--- a/drivers/net/wireless/ath/regd.c
+++ b/drivers/net/wireless/ath/regd.c
@@ -200,8 +200,10 @@ ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
 				continue;
 
 			if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
-				r = freq_reg_info(wiphy, ch->center_freq,
-					&bandwidth, &reg_rule);
+				r = freq_reg_info(wiphy,
+						  ch->center_freq,
+						  bandwidth,
+						  &reg_rule);
 				if (r)
 					continue;
 				/*
@@ -265,7 +267,7 @@ ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
 	 */
 
 	ch = &sband->channels[11]; /* CH 12 */
-	r = freq_reg_info(wiphy, ch->center_freq, &bandwidth, &reg_rule);
+	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
 	if (!r) {
 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
@@ -273,7 +275,7 @@ ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
 	}
 
 	ch = &sband->channels[12]; /* CH 13 */
-	r = freq_reg_info(wiphy, ch->center_freq, &bandwidth, &reg_rule);
+	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
 	if (!r) {
 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 9e17a83d3432..282d58d52fce 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -70,6 +70,9 @@ enum ieee80211_channel_flags {
 	IEEE80211_CHAN_NO_FAT_BELOW	= 1<<5,
 };
 
+#define IEEE80211_CHAN_NO_HT40 \
+	(IEEE80211_CHAN_NO_FAT_ABOVE | IEEE80211_CHAN_NO_FAT_BELOW)
+
 /**
  * struct ieee80211_channel - channel definition
  *
@@ -1303,9 +1306,10 @@ extern void wiphy_apply_custom_regulatory(
  * freq_reg_info - get regulatory information for the given frequency
  * @wiphy: the wiphy for which we want to process this rule for
  * @center_freq: Frequency in KHz for which we want regulatory information for
- * @bandwidth: the bandwidth requirement you have in KHz, if you do not have one
- * 	you can set this to 0. If this frequency is allowed we then set
- * 	this value to the maximum allowed bandwidth.
+ * @desired_bw_khz: the desired max bandwidth you want to use per
+ *	channel. Note that this is still 20 MHz if you want to use HT40
+ *	as HT40 makes use of two channels for its 40 MHz width bandwidth.
+ *	If set to 0 we'll assume you want the standard 20 MHz.
  * @reg_rule: the regulatory rule which we have for this frequency
  *
  * Use this function to get the regulatory rule for a specific frequency on
@@ -1320,7 +1324,9 @@ extern void wiphy_apply_custom_regulatory(
  * freq_in_rule_band() for our current definition of a band -- this is purely
  * subjective and right now its 802.11 specific.
  */
-extern int freq_reg_info(struct wiphy *wiphy, u32 center_freq, u32 *bandwidth,
+extern int freq_reg_info(struct wiphy *wiphy,
+			 u32 center_freq,
+			 u32 desired_bw_khz,
 			 const struct ieee80211_reg_rule **reg_rule);
 
 /*
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 537af62ec42b..d897528ee7fc 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -48,12 +48,6 @@ static struct regulatory_request *last_request;
 /* To trigger userspace events */
 static struct platform_device *reg_pdev;
 
-/* Keep the ordering from large to small */
-static u32 supported_bandwidths[] = {
-	MHZ_TO_KHZ(40),
-	MHZ_TO_KHZ(20),
-};
-
 /*
  * Central wireless core regulatory domains, we only need two,
  * the current one and a world regulatory domain in case we have no
@@ -435,19 +429,20 @@ static bool is_valid_rd(const struct ieee80211_regdomain *rd)
 	return true;
 }
 
-/* Returns value in KHz */
-static u32 freq_max_bandwidth(const struct ieee80211_freq_range *freq_range,
-	u32 freq)
+static bool reg_does_bw_fit(const struct ieee80211_freq_range *freq_range,
+			    u32 center_freq_khz,
+			    u32 bw_khz)
 {
-	unsigned int i;
-	for (i = 0; i < ARRAY_SIZE(supported_bandwidths); i++) {
-		u32 start_freq_khz = freq - supported_bandwidths[i]/2;
-		u32 end_freq_khz = freq + supported_bandwidths[i]/2;
-		if (start_freq_khz >= freq_range->start_freq_khz &&
-			end_freq_khz <= freq_range->end_freq_khz)
-			return supported_bandwidths[i];
-	}
-	return 0;
+	u32 start_freq_khz, end_freq_khz;
+
+	start_freq_khz = center_freq_khz - (bw_khz/2);
+	end_freq_khz = center_freq_khz + (bw_khz/2);
+
+	if (start_freq_khz >= freq_range->start_freq_khz &&
+	    end_freq_khz <= freq_range->end_freq_khz)
+		return true;
+
+	return false;
 }
 
 /**
@@ -847,14 +842,17 @@ static u32 map_regdom_flags(u32 rd_flags)
 
 static int freq_reg_info_regd(struct wiphy *wiphy,
 			      u32 center_freq,
-			      u32 *bandwidth,
+			      u32 desired_bw_khz,
 			      const struct ieee80211_reg_rule **reg_rule,
 			      const struct ieee80211_regdomain *custom_regd)
 {
 	int i;
 	bool band_rule_found = false;
 	const struct ieee80211_regdomain *regd;
-	u32 max_bandwidth = 0;
+	bool bw_fits = false;
+
+	if (!desired_bw_khz)
+		desired_bw_khz = MHZ_TO_KHZ(20);
 
 	regd = custom_regd ? custom_regd : cfg80211_regdomain;
 
@@ -887,38 +885,54 @@ static int freq_reg_info_regd(struct wiphy *wiphy,
 		if (!band_rule_found)
 			band_rule_found = freq_in_rule_band(fr, center_freq);
 
-		max_bandwidth = freq_max_bandwidth(fr, center_freq);
+		bw_fits = reg_does_bw_fit(fr,
+					  center_freq,
+					  desired_bw_khz);
 
-		if (max_bandwidth && *bandwidth <= max_bandwidth) {
+		if (band_rule_found && bw_fits) {
 			*reg_rule = rr;
-			*bandwidth = max_bandwidth;
-			break;
+			return 0;
 		}
 	}
 
 	if (!band_rule_found)
 		return -ERANGE;
 
-	return !max_bandwidth;
+	return -EINVAL;
 }
 EXPORT_SYMBOL(freq_reg_info);
 
-int freq_reg_info(struct wiphy *wiphy, u32 center_freq, u32 *bandwidth,
-			 const struct ieee80211_reg_rule **reg_rule)
+int freq_reg_info(struct wiphy *wiphy,
+		  u32 center_freq,
+		  u32 desired_bw_khz,
+		  const struct ieee80211_reg_rule **reg_rule)
 {
 	assert_cfg80211_lock();
-	return freq_reg_info_regd(wiphy, center_freq,
-		bandwidth, reg_rule, NULL);
+	return freq_reg_info_regd(wiphy,
+				  center_freq,
+				  desired_bw_khz,
+				  reg_rule,
+				  NULL);
 }
 
+/*
+ * Note that right now we assume the desired channel bandwidth
+ * is always 20 MHz for each individual channel (HT40 uses 20 MHz
+ * per channel, the primary and the extension channel). To support
+ * smaller custom bandwidths such as 5 MHz or 10 MHz we'll need a
+ * new ieee80211_channel.target_bw and re run the regulatory check
+ * on the wiphy with the target_bw specified. Then we can simply use
+ * that below for the desired_bw_khz below.
+ */
 static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
 			   unsigned int chan_idx)
 {
 	int r;
-	u32 flags;
-	u32 max_bandwidth = 0;
+	u32 flags, bw_flags = 0;
+	u32 desired_bw_khz = MHZ_TO_KHZ(20);
 	const struct ieee80211_reg_rule *reg_rule = NULL;
 	const struct ieee80211_power_rule *power_rule = NULL;
+	const struct ieee80211_freq_range *freq_range = NULL;
 	struct ieee80211_supported_band *sband;
 	struct ieee80211_channel *chan;
 	struct wiphy *request_wiphy = NULL;
@@ -933,8 +947,10 @@ static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
 
 	flags = chan->orig_flags;
 
-	r = freq_reg_info(wiphy, MHZ_TO_KHZ(chan->center_freq),
-		&max_bandwidth, &reg_rule);
+	r = freq_reg_info(wiphy,
+			  MHZ_TO_KHZ(chan->center_freq),
+			  desired_bw_khz,
+			  &reg_rule);
 
 	if (r) {
 		/*
@@ -977,6 +993,10 @@ static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
 	}
 
 	power_rule = &reg_rule->power_rule;
+	freq_range = &reg_rule->freq_range;
+
+	if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(40))
+		bw_flags = IEEE80211_CHAN_NO_HT40;
 
 	if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
 	    request_wiphy && request_wiphy == wiphy &&
@@ -987,19 +1007,19 @@ static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
 		 * settings
 		 */
 		chan->flags = chan->orig_flags =
-			map_regdom_flags(reg_rule->flags);
+			map_regdom_flags(reg_rule->flags) | bw_flags;
 		chan->max_antenna_gain = chan->orig_mag =
 			(int) MBI_TO_DBI(power_rule->max_antenna_gain);
-		chan->max_bandwidth = KHZ_TO_MHZ(max_bandwidth);
+		chan->max_bandwidth = KHZ_TO_MHZ(desired_bw_khz);
 		chan->max_power = chan->orig_mpwr =
 			(int) MBM_TO_DBM(power_rule->max_eirp);
 		return;
 	}
 
-	chan->flags = flags | map_regdom_flags(reg_rule->flags);
+	chan->flags = flags | bw_flags | map_regdom_flags(reg_rule->flags);
 	chan->max_antenna_gain = min(chan->orig_mag,
 		(int) MBI_TO_DBI(power_rule->max_antenna_gain));
-	chan->max_bandwidth = KHZ_TO_MHZ(max_bandwidth);
+	chan->max_bandwidth = KHZ_TO_MHZ(desired_bw_khz);
 	if (chan->orig_mpwr)
 		chan->max_power = min(chan->orig_mpwr,
 			(int) MBM_TO_DBM(power_rule->max_eirp));
@@ -1156,6 +1176,93 @@ static void reg_process_beacons(struct wiphy *wiphy)
 	wiphy_update_beacon_reg(wiphy);
 }
 
+static bool is_ht40_not_allowed(struct ieee80211_channel *chan)
+{
+	if (!chan)
+		return true;
+	if (chan->flags & IEEE80211_CHAN_DISABLED)
+		return true;
+	/* This would happen when regulatory rules disallow HT40 completely */
+	if (IEEE80211_CHAN_NO_HT40 == (chan->flags & (IEEE80211_CHAN_NO_HT40)))
+		return true;
+	return false;
+}
+
+static void reg_process_ht_flags_channel(struct wiphy *wiphy,
+					 enum ieee80211_band band,
+					 unsigned int chan_idx)
+{
+	struct ieee80211_supported_band *sband;
+	struct ieee80211_channel *channel;
+	struct ieee80211_channel *channel_before = NULL, *channel_after = NULL;
+	unsigned int i;
+
+	assert_cfg80211_lock();
+
+	sband = wiphy->bands[band];
+	BUG_ON(chan_idx >= sband->n_channels);
+	channel = &sband->channels[chan_idx];
+
+	if (is_ht40_not_allowed(channel)) {
+		channel->flags |= IEEE80211_CHAN_NO_HT40;
+		return;
+	}
+
+	/*
+	 * We need to ensure the extension channels exist to
+	 * be able to use HT40- or HT40+, this finds them (or not)
+	 */
+	for (i = 0; i < sband->n_channels; i++) {
+		struct ieee80211_channel *c = &sband->channels[i];
+		if (c->center_freq == (channel->center_freq - 20))
+			channel_before = c;
+		if (c->center_freq == (channel->center_freq + 20))
+			channel_after = c;
+	}
+
+	/*
+	 * Please note that this assumes target bandwidth is 20 MHz,
+	 * if that ever changes we also need to change the below logic
+	 * to include that as well.
+	 */
+	if (is_ht40_not_allowed(channel_before))
+		channel->flags |= IEEE80211_CHAN_NO_FAT_BELOW;
+	else
+		channel->flags &= ~IEEE80211_CHAN_NO_FAT_BELOW;
+
+	if (is_ht40_not_allowed(channel_after))
+		channel->flags |= IEEE80211_CHAN_NO_FAT_ABOVE;
+	else
+		channel->flags &= ~IEEE80211_CHAN_NO_FAT_ABOVE;
+}
+
+static void reg_process_ht_flags_band(struct wiphy *wiphy,
+				      enum ieee80211_band band)
+{
+	unsigned int i;
+	struct ieee80211_supported_band *sband;
+
+	BUG_ON(!wiphy->bands[band]);
+	sband = wiphy->bands[band];
+
+	for (i = 0; i < sband->n_channels; i++)
+		reg_process_ht_flags_channel(wiphy, band, i);
+}
+
+static void reg_process_ht_flags(struct wiphy *wiphy)
+{
+	enum ieee80211_band band;
+
+	if (!wiphy)
+		return;
+
+	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+		if (wiphy->bands[band])
+			reg_process_ht_flags_band(wiphy, band);
+	}
+
+}
+
 void wiphy_update_regulatory(struct wiphy *wiphy,
 			     enum nl80211_reg_initiator initiator)
 {
@@ -1169,6 +1276,7 @@ void wiphy_update_regulatory(struct wiphy *wiphy,
 	}
 out:
 	reg_process_beacons(wiphy);
+	reg_process_ht_flags(wiphy);
 	if (wiphy->reg_notifier)
 		wiphy->reg_notifier(wiphy, last_request);
 }
@@ -1179,9 +1287,11 @@ static void handle_channel_custom(struct wiphy *wiphy,
 				  const struct ieee80211_regdomain *regd)
 {
 	int r;
-	u32 max_bandwidth = 0;
+	u32 desired_bw_khz = MHZ_TO_KHZ(20);
+	u32 bw_flags = 0;
 	const struct ieee80211_reg_rule *reg_rule = NULL;
 	const struct ieee80211_power_rule *power_rule = NULL;
+	const struct ieee80211_freq_range *freq_range = NULL;
 	struct ieee80211_supported_band *sband;
 	struct ieee80211_channel *chan;
 
@@ -1191,8 +1301,11 @@ static void handle_channel_custom(struct wiphy *wiphy,
 	BUG_ON(chan_idx >= sband->n_channels);
 	chan = &sband->channels[chan_idx];
 
-	r = freq_reg_info_regd(wiphy, MHZ_TO_KHZ(chan->center_freq),
-		&max_bandwidth, &reg_rule, regd);
+	r = freq_reg_info_regd(wiphy,
+			       MHZ_TO_KHZ(chan->center_freq),
+			       desired_bw_khz,
+			       &reg_rule,
+			       regd);
 
 	if (r) {
 		chan->flags = IEEE80211_CHAN_DISABLED;
@@ -1200,10 +1313,14 @@ static void handle_channel_custom(struct wiphy *wiphy,
 	}
 
 	power_rule = &reg_rule->power_rule;
+	freq_range = &reg_rule->freq_range;
+
+	if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(40))
+		bw_flags = IEEE80211_CHAN_NO_HT40;
 
-	chan->flags |= map_regdom_flags(reg_rule->flags);
+	chan->flags |= map_regdom_flags(reg_rule->flags) | bw_flags;
 	chan->max_antenna_gain = (int) MBI_TO_DBI(power_rule->max_antenna_gain);
-	chan->max_bandwidth = KHZ_TO_MHZ(max_bandwidth);
+	chan->max_bandwidth = KHZ_TO_MHZ(desired_bw_khz);
 	chan->max_power = (int) MBM_TO_DBM(power_rule->max_eirp);
 }