[PATCH v2 05/22] nl80211: support setting S1G channels

Thomas Pedersen
2020-08-31T20:56:18Z

S1G channels have a single width defined per frequency, so
derive it from the channel flags with
ieee80211_s1g_channel_width().

Also support setting an S1G channel where control frequency may
differ from operating, and add some basic validation to
ensure the control channel is with the operating.

Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
---
include/net/cfg80211.h | 10 ++++
net/wireless/chan.c | 130 ++++++++++++++++++++++++-----------------
net/wireless/util.c | 27 +++++++++
3 files changed, 115 insertions(+), 52 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index e4d4fbcb2edc..d3d85bd9c0aa 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -5293,6 +5293,16 @@ ieee80211_channel_to_khz(const struct ieee80211_channel *chan)
return MHZ_TO_KHZ(chan->center_freq) + chan->freq_offset;
}

+/**
+ * ieee80211_s1g_channel_width - get allowed channel width from @chan
+ *
+ * Only allowed for band NL80211_BAND_S1GHZ
+ * @chan: channel
+ * Return: The allowed channel width for this center_freq
+ */
+enum nl80211_chan_width
+ieee80211_s1g_channel_width(const struct ieee80211_channel *chan);
+
/**
* ieee80211_channel_to_freq_khz - convert channel number to frequency
* @chan: channel number
diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 6a6f2f214c10..96e24ee4c7e8 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -141,9 +141,62 @@ static bool cfg80211_edmg_chandef_valid(const struct cfg80211_chan_def *chandef)
return true;
}

+static int nl80211_chan_width_to_mhz(enum nl80211_chan_width chan_width)
+{
+ int mhz;
+
+ switch (chan_width) {
+ case NL80211_CHAN_WIDTH_1:
+ mhz = 1;
+ break;
+ case NL80211_CHAN_WIDTH_2:
+ mhz = 2;
+ break;
+ case NL80211_CHAN_WIDTH_4:
+ mhz = 4;
+ break;
+ case NL80211_CHAN_WIDTH_8:
+ mhz = 8;
+ break;
+ case NL80211_CHAN_WIDTH_16:
+ mhz = 16;
+ break;
+ case NL80211_CHAN_WIDTH_5:
+ mhz = 5;
+ break;
+ case NL80211_CHAN_WIDTH_10:
+ mhz = 10;
+ break;
+ case NL80211_CHAN_WIDTH_20:
+ case NL80211_CHAN_WIDTH_20_NOHT:
+ mhz = 20;
+ break;
+ case NL80211_CHAN_WIDTH_40:
+ mhz = 40;
+ break;
+ case NL80211_CHAN_WIDTH_80P80:
+ case NL80211_CHAN_WIDTH_80:
+ mhz = 80;
+ break;
+ case NL80211_CHAN_WIDTH_160:
+ mhz = 160;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -1;
+ }
+ return mhz;
+}
+
+static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
+{
+ return nl80211_chan_width_to_mhz(c->width);
+}
+
bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
{
- u32 control_freq;
+ u32 control_freq, oper_freq;
+ int oper_width, control_width;

if (!chandef->chan)
return false;
@@ -155,10 +208,6 @@ bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)

switch (chandef->width) {
case NL80211_CHAN_WIDTH_1:
- case NL80211_CHAN_WIDTH_2:
- case NL80211_CHAN_WIDTH_4:
- case NL80211_CHAN_WIDTH_8:
- case NL80211_CHAN_WIDTH_16:
case NL80211_CHAN_WIDTH_5:
case NL80211_CHAN_WIDTH_10:
case NL80211_CHAN_WIDTH_20:
@@ -169,6 +218,30 @@ bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
if (chandef->center_freq2)
return false;
break;
+ case NL80211_CHAN_WIDTH_2:
+ case NL80211_CHAN_WIDTH_4:
+ case NL80211_CHAN_WIDTH_8:
+ case NL80211_CHAN_WIDTH_16:
+ control_freq = ieee80211_channel_to_khz(chandef->chan);
+ oper_freq = ieee80211_chandef_to_khz(chandef);
+ control_width = nl80211_chan_width_to_mhz(
+ ieee80211_s1g_channel_width(
+ chandef->chan));
+ oper_width = cfg80211_chandef_get_width(chandef);
+
+ if (oper_width < 0 || control_width < 0)
+ return false;
+ if (chandef->center_freq2)
+ return false;
+
+ if (control_freq + MHZ_TO_KHZ(control_width) / 2 >
+ oper_freq + MHZ_TO_KHZ(oper_width) / 2)
+ return false;
+
+ if (control_freq - MHZ_TO_KHZ(control_width) / 2 <
+ oper_freq - MHZ_TO_KHZ(oper_width) / 2)
+ return false;
+ break;
case NL80211_CHAN_WIDTH_40:
if (chandef->center_freq1 != control_freq + 10 &&
chandef->center_freq1 != control_freq - 10)
@@ -264,53 +337,6 @@ static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
}
}

-static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
-{
- int width;
-
- switch (c->width) {
- case NL80211_CHAN_WIDTH_1:
- width = 1;
- break;
- case NL80211_CHAN_WIDTH_2:
- width = 2;
- break;
- case NL80211_CHAN_WIDTH_4:
- width = 4;
- break;
- case NL80211_CHAN_WIDTH_8:
- width = 8;
- break;
- case NL80211_CHAN_WIDTH_16:
- width = 16;
- break;
- case NL80211_CHAN_WIDTH_5:
- width = 5;
- break;
- case NL80211_CHAN_WIDTH_10:
- width = 10;
- break;
- case NL80211_CHAN_WIDTH_20:
- case NL80211_CHAN_WIDTH_20_NOHT:
- width = 20;
- break;
- case NL80211_CHAN_WIDTH_40:
- width = 40;
- break;
- case NL80211_CHAN_WIDTH_80P80:
- case NL80211_CHAN_WIDTH_80:
- width = 80;
- break;
- case NL80211_CHAN_WIDTH_160:
- width = 160;
- break;
- default:
- WARN_ON_ONCE(1);
- return -1;
- }
- return width;
-}
-
const struct cfg80211_chan_def *
cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
const struct cfg80211_chan_def *c2)
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 49e7c0cbbf62..ac2bb1a80f2b 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -111,6 +111,33 @@ u32 ieee80211_channel_to_freq_khz(int chan, enum nl80211_band band)
}
EXPORT_SYMBOL(ieee80211_channel_to_freq_khz);

+enum nl80211_chan_width
+ieee80211_s1g_channel_width(const struct ieee80211_channel *chan)
+{
+ if (WARN_ON(!chan || chan->band != NL80211_BAND_S1GHZ))
+ return NL80211_CHAN_WIDTH_20_NOHT;
+
+ /*S1G defines a single allowed channel width per channel.
+ * Extract that width here.
+ */
+ if (chan->flags & IEEE80211_CHAN_1MHZ)
+ return NL80211_CHAN_WIDTH_1;
+ else if (chan->flags & IEEE80211_CHAN_2MHZ)
+ return NL80211_CHAN_WIDTH_2;
+ else if (chan->flags & IEEE80211_CHAN_4MHZ)
+ return NL80211_CHAN_WIDTH_4;
+ else if (chan->flags & IEEE80211_CHAN_8MHZ)
+ return NL80211_CHAN_WIDTH_8;
+ else if (chan->flags & IEEE80211_CHAN_16MHZ)
+ return NL80211_CHAN_WIDTH_16;
+
+ pr_err("unknown channel width for channel at %dKHz?\n",
+ ieee80211_channel_to_khz(chan));
+
+ return NL80211_CHAN_WIDTH_1;
+}
+EXPORT_SYMBOL(ieee80211_s1g_channel_width);
+
int ieee80211_freq_khz_to_channel(u32 freq)
{
/* TODO: just handle MHz for now */
--
2.20.1