From 19468413e8d98d44be8daf0acaf8d576dfc53fa2 Mon Sep 17 00:00:00 2001 From: Simon Wunderlich Date: Sat, 28 Jan 2012 17:25:33 +0100 Subject: 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 Signed-off-by: Mathias Kretschmer Signed-off-by: John W. Linville --- net/mac80211/rate.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 116 insertions(+), 8 deletions(-) (limited to 'net/mac80211/rate.c') 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); } } -- cgit v1.2.3