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authorSimon Wunderlich <simon.wunderlich@s2003.tu-chemnitz.de>2012-01-28 17:25:33 +0100
committerJohn W. Linville <linville@tuxdriver.com>2012-01-30 15:48:26 -0500
commit19468413e8d98d44be8daf0acaf8d576dfc53fa2 (patch)
tree99d7df720566824c4588ccff03c65e60c381e60d /net/mac80211/rate.c
parent24db78c05b1e3ccb5a78aedd17aa1008c91dab5a (diff)
mac80211: add support for mcs masks
* Handle MCS masks set by the user. * Match rates provided by the rate control algorithm to the mask set, also in HT mode, and switch back to legacy mode if necessary. * add debugfs files to observate the rate selection Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/rate.c')
-rw-r--r--net/mac80211/rate.c124
1 files changed, 116 insertions, 8 deletions
diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index a21110aecd1..3fef26d8898 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -289,8 +289,8 @@ bool rate_control_send_low(struct ieee80211_sta *sta,
}
EXPORT_SYMBOL(rate_control_send_low);
-static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
- int n_bitrates, u32 mask)
+static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
+ int n_bitrates, u32 mask)
{
int j;
@@ -299,7 +299,7 @@ static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
if (mask & (1 << j)) {
/* Okay, found a suitable rate. Use it. */
rate->idx = j;
- return;
+ return true;
}
}
@@ -308,6 +308,112 @@ static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
if (mask & (1 << j)) {
/* Okay, found a suitable rate. Use it. */
rate->idx = j;
+ return true;
+ }
+ }
+ return false;
+}
+
+static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
+ u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
+{
+ int i, j;
+ int ridx, rbit;
+
+ ridx = rate->idx / 8;
+ rbit = rate->idx % 8;
+
+ /* sanity check */
+ if (ridx < 0 || ridx > IEEE80211_HT_MCS_MASK_LEN)
+ return false;
+
+ /* See whether the selected rate or anything below it is allowed. */
+ for (i = ridx; i >= 0; i--) {
+ for (j = rbit; j >= 0; j--)
+ if (mcs_mask[i] & BIT(j)) {
+ rate->idx = i * 8 + j;
+ return true;
+ }
+ rbit = 7;
+ }
+
+ /* Try to find a higher rate that would be allowed */
+ ridx = (rate->idx + 1) / 8;
+ rbit = (rate->idx + 1) % 8;
+
+ for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
+ for (j = rbit; j < 8; j++)
+ if (mcs_mask[i] & BIT(j)) {
+ rate->idx = i * 8 + j;
+ return true;
+ }
+ rbit = 0;
+ }
+ return false;
+}
+
+
+
+static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
+ struct ieee80211_tx_rate_control *txrc,
+ u32 mask,
+ u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
+{
+ struct ieee80211_tx_rate alt_rate;
+
+ /* handle HT rates */
+ if (rate->flags & IEEE80211_TX_RC_MCS) {
+ if (rate_idx_match_mcs_mask(rate, mcs_mask))
+ return;
+
+ /* also try the legacy rates. */
+ alt_rate.idx = 0;
+ /* keep protection flags */
+ alt_rate.flags = rate->flags &
+ (IEEE80211_TX_RC_USE_RTS_CTS |
+ IEEE80211_TX_RC_USE_CTS_PROTECT |
+ IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
+ alt_rate.count = rate->count;
+ if (rate_idx_match_legacy_mask(&alt_rate,
+ txrc->sband->n_bitrates,
+ mask)) {
+ *rate = alt_rate;
+ return;
+ }
+ } else {
+ struct sk_buff *skb = txrc->skb;
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ __le16 fc;
+
+ /* handle legacy rates */
+ if (rate_idx_match_legacy_mask(rate, txrc->sband->n_bitrates,
+ mask))
+ return;
+
+ /* if HT BSS, and we handle a data frame, also try HT rates */
+ if (txrc->bss_conf->channel_type == NL80211_CHAN_NO_HT)
+ return;
+
+ fc = hdr->frame_control;
+ if (!ieee80211_is_data(fc))
+ return;
+
+ alt_rate.idx = 0;
+ /* keep protection flags */
+ alt_rate.flags = rate->flags &
+ (IEEE80211_TX_RC_USE_RTS_CTS |
+ IEEE80211_TX_RC_USE_CTS_PROTECT |
+ IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
+ alt_rate.count = rate->count;
+
+ alt_rate.flags |= IEEE80211_TX_RC_MCS;
+
+ if ((txrc->bss_conf->channel_type == NL80211_CHAN_HT40MINUS) ||
+ (txrc->bss_conf->channel_type == NL80211_CHAN_HT40PLUS))
+ alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
+
+ if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
+ *rate = alt_rate;
return;
}
}
@@ -331,6 +437,7 @@ void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
int i;
u32 mask;
+ u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
if (sta) {
ista = &sta->sta;
@@ -354,10 +461,14 @@ void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
* the common case.
*/
mask = sdata->rc_rateidx_mask[info->band];
+ memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
+ sizeof(mcs_mask));
if (mask != (1 << txrc->sband->n_bitrates) - 1) {
if (sta) {
/* Filter out rates that the STA does not support */
mask &= sta->sta.supp_rates[info->band];
+ for (i = 0; i < sizeof(mcs_mask); i++)
+ mcs_mask[i] &= sta->sta.ht_cap.mcs.rx_mask[i];
}
/*
* Make sure the rate index selected for each TX rate is
@@ -368,11 +479,8 @@ void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
/* Skip invalid rates */
if (info->control.rates[i].idx < 0)
break;
- /* Rate masking supports only legacy rates for now */
- if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
- continue;
- rate_idx_match_mask(&info->control.rates[i],
- txrc->sband->n_bitrates, mask);
+ rate_idx_match_mask(&info->control.rates[i], txrc,
+ mask, mcs_mask);
}
}