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>

2 files changed, 6 insertions, 15 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index a8d5d04314b9..22e062afb5a1 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -857,20 +857,11 @@ enum tx_power_setting {
  * cfg80211_bitrate_mask - masks for bitrate control
  */
 struct cfg80211_bitrate_mask {
-/*
- * As discussed in Berlin, this struct really
- * should look like this:
-
 	struct {
 		u32 legacy;
-		u8 mcs[IEEE80211_HT_MCS_MASK_LEN];
+		/* TODO: add support for masking MCS rates; e.g.: */
+		/* u8 mcs[IEEE80211_HT_MCS_MASK_LEN]; */
 	} control[IEEE80211_NUM_BANDS];
-
- * Since we can always fix in-kernel users, let's keep
- * it simpler for now:
- */
-	u32 fixed;   /* fixed bitrate, 0 == not fixed */
-	u32 maxrate; /* in kbps, 0 == no limit */
 };
 /**
  * struct cfg80211_pmksa - PMK Security Association
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 39c516c352be..7e5af6d90b93 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -255,9 +255,6 @@ struct ieee80211_bss_conf {
  * @IEEE80211_TX_CTL_RATE_CTRL_PROBE: internal to mac80211, can be
  *	set by rate control algorithms to indicate probe rate, will
  *	be cleared for fragmented frames (except on the last fragment)
- * @IEEE80211_TX_INTFL_RCALGO: mac80211 internal flag, do not test or
- *	set this flag in the driver; indicates that the rate control
- *	algorithm was used and should be notified of TX status
  * @IEEE80211_TX_INTFL_NEED_TXPROCESSING: completely internal to mac80211,
  *	used to indicate that a pending frame requires TX processing before
  *	it can be sent out.
@@ -287,7 +284,6 @@ enum mac80211_tx_control_flags {
 	IEEE80211_TX_STAT_AMPDU			= BIT(10),
 	IEEE80211_TX_STAT_AMPDU_NO_BACK		= BIT(11),
 	IEEE80211_TX_CTL_RATE_CTRL_PROBE	= BIT(12),
-	IEEE80211_TX_INTFL_RCALGO		= BIT(13),
 	IEEE80211_TX_INTFL_NEED_TXPROCESSING	= BIT(14),
 	IEEE80211_TX_INTFL_RETRIED		= BIT(15),
 	IEEE80211_TX_INTFL_DONT_ENCRYPT		= BIT(16),
@@ -2297,6 +2293,9 @@ enum rate_control_changed {
  * @short_preamble: whether mac80211 will request short-preamble transmission
  *	if the selected rate supports it
  * @max_rate_idx: user-requested maximum rate (not MCS for now)
+ *	(deprecated; this will be removed once drivers get updated to use
+ *	rate_idx_mask)
+ * @rate_idx_mask: user-requested rate mask (not MCS for now)
  * @skb: the skb that will be transmitted, the control information in it needs
  *	to be filled in
  * @ap: whether this frame is sent out in AP mode
@@ -2309,6 +2308,7 @@ struct ieee80211_tx_rate_control {
 	struct ieee80211_tx_rate reported_rate;
 	bool rts, short_preamble;
 	u8 max_rate_idx;
+	u32 rate_idx_mask;
 	bool ap;
 };