cfg80211: express channels with a KHz component

Some bands (S1G) define channels centered on a non-integer
MHz. Give ieee80211_channel and cfg80211_chan_def a
freq_offset component where the final frequency can be
expressed as:

MHZ_TO_KHZ(chan->center_freq) + chan->freq_offset;

Also provide some helper functions to do the frequency
conversion and test for equality.

Retain the existing interface to frequency and channel
conversion helpers, and expose new ones which handle
frequencies in units of KHz.

Some internal functions (net/wireless/chan.c) pass around
a frequency value. Convert these to units of KHz.

mesh, ibss, wext, etc. are currently ignored.

Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200402011810.22947-3-thomas@adapt-ip.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 38 insertions, 30 deletions

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index fcac5c6366e1..d60e50a3b910 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -27,6 +27,7 @@ void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
 		return;
 
 	chandef->chan = chan;
+	chandef->freq1_offset = chan->freq_offset;
 	chandef->center_freq2 = 0;
 	chandef->edmg.bw_config = 0;
 	chandef->edmg.channels = 0;
@@ -153,7 +154,8 @@ bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
 	case NL80211_CHAN_WIDTH_10:
 	case NL80211_CHAN_WIDTH_20:
 	case NL80211_CHAN_WIDTH_20_NOHT:
-		if (chandef->center_freq1 != control_freq)
+		if (ieee80211_chandef_to_khz(chandef) !=
+		    ieee80211_channel_to_khz(chandef->chan))
 			return false;
 		if (chandef->center_freq2)
 			return false;
@@ -386,10 +388,11 @@ static u32 cfg80211_get_start_freq(u32 center_freq,
 {
 	u32 start_freq;
 
-	if (bandwidth <= 20)
+	bandwidth = MHZ_TO_KHZ(bandwidth);
+	if (bandwidth <= MHZ_TO_KHZ(20))
 		start_freq = center_freq;
 	else
-		start_freq = center_freq - bandwidth/2 + 10;
+		start_freq = center_freq - bandwidth / 2 + MHZ_TO_KHZ(10);
 
 	return start_freq;
 }
@@ -399,10 +402,11 @@ static u32 cfg80211_get_end_freq(u32 center_freq,
 {
 	u32 end_freq;
 
-	if (bandwidth <= 20)
+	bandwidth = MHZ_TO_KHZ(bandwidth);
+	if (bandwidth <= MHZ_TO_KHZ(20))
 		end_freq = center_freq;
 	else
-		end_freq = center_freq + bandwidth/2 - 10;
+		end_freq = center_freq + bandwidth / 2 - MHZ_TO_KHZ(10);
 
 	return end_freq;
 }
@@ -417,8 +421,8 @@ static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
 
-	for (freq = start_freq; freq <= end_freq; freq += 20) {
-		c = ieee80211_get_channel(wiphy, freq);
+	for (freq = start_freq; freq <= end_freq; freq += MHZ_TO_KHZ(20)) {
+		c = ieee80211_get_channel_khz(wiphy, freq);
 		if (!c)
 			return -EINVAL;
 
@@ -449,8 +453,8 @@ int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
 			return -EINVAL;
 
 		ret = cfg80211_get_chans_dfs_required(wiphy,
-						      chandef->center_freq1,
-						      width);
+					ieee80211_chandef_to_khz(chandef),
+					width);
 		if (ret < 0)
 			return ret;
 		else if (ret > 0)
@@ -460,8 +464,8 @@ int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
 			return 0;
 
 		ret = cfg80211_get_chans_dfs_required(wiphy,
-						      chandef->center_freq2,
-						      width);
+					MHZ_TO_KHZ(chandef->center_freq2),
+					width);
 		if (ret < 0)
 			return ret;
 		else if (ret > 0)
@@ -503,8 +507,8 @@ static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
 	 * DFS_AVAILABLE). Return number of usable channels
 	 * (require CAC). Allow DFS and non-DFS channel mix.
 	 */
-	for (freq = start_freq; freq <= end_freq; freq += 20) {
-		c = ieee80211_get_channel(wiphy, freq);
+	for (freq = start_freq; freq <= end_freq; freq += MHZ_TO_KHZ(20)) {
+		c = ieee80211_get_channel_khz(wiphy, freq);
 		if (!c)
 			return -EINVAL;
 
@@ -536,8 +540,9 @@ bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
 	if (width < 0)
 		return false;
 
-	r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
-					  width);
+	r1 = cfg80211_get_chans_dfs_usable(wiphy,
+					   MHZ_TO_KHZ(chandef->center_freq1),
+					   width);
 
 	if (r1 < 0)
 		return false;
@@ -546,8 +551,8 @@ bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
 	case NL80211_CHAN_WIDTH_80P80:
 		WARN_ON(!chandef->center_freq2);
 		r2 = cfg80211_get_chans_dfs_usable(wiphy,
-						   chandef->center_freq2,
-						   width);
+					MHZ_TO_KHZ(chandef->center_freq2),
+					width);
 		if (r2 < 0)
 			return false;
 		break;
@@ -694,8 +699,8 @@ static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
 	 * If any channel in between is disabled or has not
 	 * had gone through CAC return false
 	 */
-	for (freq = start_freq; freq <= end_freq; freq += 20) {
-		c = ieee80211_get_channel(wiphy, freq);
+	for (freq = start_freq; freq <= end_freq; freq += MHZ_TO_KHZ(20)) {
+		c = ieee80211_get_channel_khz(wiphy, freq);
 		if (!c)
 			return false;
 
@@ -724,7 +729,8 @@ static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
 	if (width < 0)
 		return false;
 
-	r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
+	r = cfg80211_get_chans_dfs_available(wiphy,
+					     MHZ_TO_KHZ(chandef->center_freq1),
 					     width);
 
 	/* If any of channels unavailable for cf1 just return */
@@ -735,8 +741,8 @@ static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
 	case NL80211_CHAN_WIDTH_80P80:
 		WARN_ON(!chandef->center_freq2);
 		r = cfg80211_get_chans_dfs_available(wiphy,
-						     chandef->center_freq2,
-						     width);
+					MHZ_TO_KHZ(chandef->center_freq2),
+					width);
 		break;
 	default:
 		WARN_ON(chandef->center_freq2);
@@ -757,8 +763,8 @@ static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
 
-	for (freq = start_freq; freq <= end_freq; freq += 20) {
-		c = ieee80211_get_channel(wiphy, freq);
+	for (freq = start_freq; freq <= end_freq; freq += MHZ_TO_KHZ(20)) {
+		c = ieee80211_get_channel_khz(wiphy, freq);
 		if (!c)
 			return 0;
 
@@ -790,14 +796,14 @@ cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
 		return 0;
 
 	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
-					     chandef->center_freq1,
+					     MHZ_TO_KHZ(chandef->center_freq1),
 					     width);
 
 	if (!chandef->center_freq2)
 		return t1;
 
 	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
-					     chandef->center_freq2,
+					     MHZ_TO_KHZ(chandef->center_freq2),
 					     width);
 
 	return max(t1, t2);
@@ -813,8 +819,8 @@ static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
 	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
 	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
 
-	for (freq = start_freq; freq <= end_freq; freq += 20) {
-		c = ieee80211_get_channel(wiphy, freq);
+	for (freq = start_freq; freq <= end_freq; freq += MHZ_TO_KHZ(20)) {
+		c = ieee80211_get_channel_khz(wiphy, freq);
 		if (!c || c->flags & prohibited_flags)
 			return false;
 	}
@@ -976,13 +982,15 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
 		prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
 
 
-	if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
+	if (!cfg80211_secondary_chans_ok(wiphy,
+					 ieee80211_chandef_to_khz(chandef),
 					 width, prohibited_flags))
 		return false;
 
 	if (!chandef->center_freq2)
 		return true;
-	return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
+	return cfg80211_secondary_chans_ok(wiphy,
+					   MHZ_TO_KHZ(chandef->center_freq2),
 					   width, prohibited_flags);
 }
 EXPORT_SYMBOL(cfg80211_chandef_usable);