cfg80211/mac80211: Use more generic bitrate mask for rate control

Extend struct cfg80211_bitrate_mask to actually use a bitfield mask
instead of just a single fixed or maximum rate index. This change
itself does not modify the behavior (except for debugfs files), but it
prepares cfg80211 and mac80211 for a new nl80211 command for setting
which rates can be used in TX rate control.

Since frames are now going through the rate control algorithm
unconditionally, the internal IEEE80211_TX_INTFL_RCALGO flag can now
be removed. The RC implementations can use the rate_idx_mask value to
optimize their behavior if only a single rate is enabled.

The old max_rate_idx in struct ieee80211_tx_rate_control is maintained
(but commented as deprecated) for backwards compatibility with existing
RC implementations. Once these implementations have been updated to
use the more generic rate_idx_mask, the max_rate_idx value can be
removed.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 30 insertions, 4 deletions

diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index 4198243a3df..966d2f01bea 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -1204,21 +1204,47 @@ int cfg80211_wext_siwrate(struct net_device *dev,
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
 	struct cfg80211_bitrate_mask mask;
+	u32 fixed, maxrate;
+	struct ieee80211_supported_band *sband;
+	int band, ridx;
+	bool match = false;
 
 	if (!rdev->ops->set_bitrate_mask)
 		return -EOPNOTSUPP;
 
-	mask.fixed = 0;
-	mask.maxrate = 0;
+	memset(&mask, 0, sizeof(mask));
+	fixed = 0;
+	maxrate = 0;
 
 	if (rate->value < 0) {
 		/* nothing */
 	} else if (rate->fixed) {
-		mask.fixed = rate->value / 1000; /* kbps */
+		fixed = rate->value / 100000;
 	} else {
-		mask.maxrate = rate->value / 1000; /* kbps */
+		maxrate = rate->value / 100000;
+	}
+
+	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+		sband = wdev->wiphy->bands[band];
+		if (sband == NULL)
+			continue;
+		for (ridx = 0; ridx < sband->n_bitrates; ridx++) {
+			struct ieee80211_rate *srate = &sband->bitrates[ridx];
+			if (fixed == srate->bitrate) {
+				mask.control[band].legacy = 1 << ridx;
+				match = true;
+				break;
+			}
+			if (srate->bitrate <= maxrate) {
+				mask.control[band].legacy |= 1 << ridx;
+				match = true;
+			}
+		}
 	}
 
+	if (!match)
+		return -EINVAL;
+
 	return rdev->ops->set_bitrate_mask(wdev->wiphy, dev, NULL, &mask);
 }
 EXPORT_SYMBOL_GPL(cfg80211_wext_siwrate);