mac80211: add A-MSDU tx support

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 48637
This commit is contained in:
Felix Fietkau 2016-02-05 16:43:38 +00:00
parent 351be0fdec
commit b0c782be70

View file

@ -0,0 +1,284 @@
From: Felix Fietkau <nbd@openwrt.org>
Date: Fri, 5 Feb 2016 01:38:51 +0100
Subject: [PATCH] mac80211: add A-MSDU tx support
Requires software tx queueing support. frag_list support (for zero-copy)
is optional.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -709,6 +709,7 @@ enum mac80211_tx_info_flags {
* @IEEE80211_TX_CTRL_PS_RESPONSE: This frame is a response to a poll
* frame (PS-Poll or uAPSD).
* @IEEE80211_TX_CTRL_RATE_INJECT: This frame is injected with rate information
+ * @IEEE80211_TX_CTRL_AMSDU: This frame is an A-MSDU frame
*
* These flags are used in tx_info->control.flags.
*/
@@ -716,6 +717,7 @@ enum mac80211_tx_control_flags {
IEEE80211_TX_CTRL_PORT_CTRL_PROTO = BIT(0),
IEEE80211_TX_CTRL_PS_RESPONSE = BIT(1),
IEEE80211_TX_CTRL_RATE_INJECT = BIT(2),
+ IEEE80211_TX_CTRL_AMSDU = BIT(3),
};
/*
@@ -1961,6 +1963,12 @@ struct ieee80211_txq {
* order and does not need to manage its own reorder buffer or BA session
* timeout.
*
+ * @IEEE80211_HW_TX_AMSDU: Hardware (or driver) supports software aggregated
+ * A-MSDU frames. Requires software tx queueing support.
+ *
+ * @IEEE80211_HW_TX_FRAG_LIST: Hardware (or driver) supports sending frag_list
+ * skbs, needed for zero-copy software A-MSDU.
+ *
* @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
*/
enum ieee80211_hw_flags {
@@ -1998,6 +2006,8 @@ enum ieee80211_hw_flags {
IEEE80211_HW_BEACON_TX_STATUS,
IEEE80211_HW_NEEDS_UNIQUE_STA_ADDR,
IEEE80211_HW_SUPPORTS_REORDERING_BUFFER,
+ IEEE80211_HW_TX_AMSDU,
+ IEEE80211_HW_TX_FRAG_LIST,
/* keep last, obviously */
NUM_IEEE80211_HW_FLAGS
@@ -2070,6 +2080,9 @@ enum ieee80211_hw_flags {
* size is smaller (an example is LinkSys WRT120N with FW v1.0.07
* build 002 Jun 18 2012).
*
+ * @max_tx_amsdu_subframes: maximum number of subframes used in software
+ * A-MSDU aggregation
+ *
* @offchannel_tx_hw_queue: HW queue ID to use for offchannel TX
* (if %IEEE80211_HW_QUEUE_CONTROL is set)
*
@@ -2124,6 +2137,7 @@ struct ieee80211_hw {
u8 max_rate_tries;
u8 max_rx_aggregation_subframes;
u8 max_tx_aggregation_subframes;
+ u8 max_tx_amsdu_subframes;
u8 offchannel_tx_hw_queue;
u8 radiotap_mcs_details;
u16 radiotap_vht_details;
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -935,6 +935,7 @@ void ieee80211_process_addba_resp(struct
size_t len)
{
struct tid_ampdu_tx *tid_tx;
+ struct ieee80211_txq *txq;
u16 capab, tid;
u8 buf_size;
bool amsdu;
@@ -945,6 +946,10 @@ void ieee80211_process_addba_resp(struct
buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes);
+ txq = sta->sta.txq[tid];
+ if (!amsdu && txq)
+ set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags);
+
mutex_lock(&sta->ampdu_mlme.mtx);
tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -127,6 +127,8 @@ static const char *hw_flag_names[NUM_IEE
FLAG(BEACON_TX_STATUS),
FLAG(NEEDS_UNIQUE_STA_ADDR),
FLAG(SUPPORTS_REORDERING_BUFFER),
+ FLAG(TX_AMSDU),
+ FLAG(TX_FRAG_LIST),
/* keep last for the build bug below */
(void *)0x1
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -799,6 +799,7 @@ struct mac80211_qos_map {
enum txq_info_flags {
IEEE80211_TXQ_STOP,
IEEE80211_TXQ_AMPDU,
+ IEEE80211_TXQ_NO_AMSDU,
};
struct txq_info {
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1318,6 +1318,10 @@ struct sk_buff *ieee80211_tx_dequeue(str
out:
spin_unlock_bh(&txqi->queue.lock);
+ if (skb && skb_has_frag_list(skb) &&
+ !ieee80211_hw_check(&local->hw, TX_FRAG_LIST))
+ skb_linearize(skb);
+
return skb;
}
EXPORT_SYMBOL(ieee80211_tx_dequeue);
@@ -2757,6 +2761,149 @@ void ieee80211_clear_fast_xmit(struct st
kfree_rcu(fast_tx, rcu_head);
}
+static int ieee80211_amsdu_pad(struct sk_buff *skb, int subframe_len)
+{
+ int amsdu_len = subframe_len + sizeof(struct ethhdr);
+ int padding = (4 - amsdu_len) & 3;
+
+ if (padding)
+ memset(skb_put(skb, padding), 0, padding);
+
+ return padding;
+}
+
+static bool ieee80211_amsdu_prepare_head(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_fast_tx *fast_tx,
+ struct sk_buff *skb)
+{
+ struct ieee80211_local *local = sdata->local;
+ struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+ struct ieee80211_hdr *hdr;
+ struct ethhdr amsdu_hdr;
+ int hdr_len = fast_tx->hdr_len - sizeof(rfc1042_header);
+ int subframe_len = skb->len - hdr_len;
+ void *data;
+ u8 *qc;
+
+ if (info->control.flags & IEEE80211_TX_CTRL_AMSDU)
+ return true;
+
+ if (skb_headroom(skb) < sizeof(amsdu_hdr) || skb_tailroom(skb) < 3) {
+ I802_DEBUG_INC(local->tx_expand_skb_head);
+
+ if (pskb_expand_head(skb, sizeof(amsdu_hdr), 3, GFP_ATOMIC)) {
+ wiphy_debug(local->hw.wiphy,
+ "failed to reallocate TX buffer\n");
+ return false;
+ }
+ }
+
+ subframe_len += ieee80211_amsdu_pad(skb, subframe_len);
+
+ amsdu_hdr.h_proto = cpu_to_be16(subframe_len);
+ memcpy(amsdu_hdr.h_source, skb->data + fast_tx->sa_offs, ETH_ALEN);
+ memcpy(amsdu_hdr.h_dest, skb->data + fast_tx->da_offs, ETH_ALEN);
+
+ data = skb_push(skb, sizeof(amsdu_hdr));
+ memmove(data, data + sizeof(amsdu_hdr), hdr_len);
+ memcpy(data + hdr_len, &amsdu_hdr, sizeof(amsdu_hdr));
+
+ hdr = data;
+ qc = ieee80211_get_qos_ctl(hdr);
+ *qc |= IEEE80211_QOS_CTL_A_MSDU_PRESENT;
+
+ info->control.flags |= IEEE80211_TX_CTRL_AMSDU;
+
+ return true;
+}
+
+static bool ieee80211_amsdu_aggregate(struct ieee80211_sub_if_data *sdata,
+ struct sta_info *sta,
+ struct ieee80211_fast_tx *fast_tx,
+ struct sk_buff *skb)
+{
+ struct ieee80211_local *local = sdata->local;
+ u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
+ struct ieee80211_txq *txq = sta->sta.txq[tid];
+ struct txq_info *txqi;
+ struct sk_buff **frag_tail, *head;
+ int subframe_len = skb->len - ETH_ALEN;
+ int max_amsdu_len;
+ __be16 len;
+ void *data;
+ bool ret = false;
+ int n = 1;
+
+ if (!ieee80211_hw_check(&local->hw, TX_AMSDU))
+ return false;
+
+ if (!txq)
+ return false;
+
+ txqi = to_txq_info(txq);
+ if (test_bit(IEEE80211_TXQ_NO_AMSDU, &txqi->flags))
+ return false;
+
+ /*
+ * A-MPDU limits maximum MPDU size to 4095 bytes. Since aggregation
+ * sessions are started/stopped without txq flush, use the limit here
+ * to avoid having to de-aggregate later.
+ */
+ max_amsdu_len = min_t(int, sta->sta.max_amsdu_len, 4095);
+
+ spin_lock_bh(&txqi->queue.lock);
+
+ head = skb_peek_tail(&txqi->queue);
+ if (!head)
+ goto out;
+
+ if (skb->len + head->len > max_amsdu_len)
+ goto out;
+
+ if (!ieee80211_amsdu_prepare_head(sdata, fast_tx, head))
+ goto out;
+
+ frag_tail = &skb_shinfo(head)->frag_list;
+ while (*frag_tail) {
+ frag_tail = &(*frag_tail)->next;
+ n++;
+ }
+
+ if (local->hw.max_tx_amsdu_subframes &&
+ n > local->hw.max_tx_amsdu_subframes)
+ goto out;
+
+ if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 3) {
+ I802_DEBUG_INC(local->tx_expand_skb_head);
+
+ if (pskb_expand_head(skb, 8, 3, GFP_ATOMIC)) {
+ wiphy_debug(local->hw.wiphy,
+ "failed to reallocate TX buffer\n");
+ goto out;
+ }
+ }
+
+ subframe_len += ieee80211_amsdu_pad(skb, subframe_len);
+
+ ret = true;
+ data = skb_push(skb, ETH_ALEN + 2);
+ memmove(data, data + ETH_ALEN + 2, 2 * ETH_ALEN);
+
+ data += 2 * ETH_ALEN;
+ len = cpu_to_be16(subframe_len);
+ memcpy(data, &len, 2);
+ memcpy(data + 2, rfc1042_header, ETH_ALEN);
+
+ head->len += skb->len;
+ head->data_len += skb->len;
+ *frag_tail = skb;
+
+out:
+ spin_unlock_bh(&txqi->queue.lock);
+
+ return ret;
+}
+
static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
struct net_device *dev, struct sta_info *sta,
struct ieee80211_fast_tx *fast_tx,
@@ -2811,6 +2958,10 @@ static bool ieee80211_xmit_fast(struct i
ieee80211_tx_stats(dev, skb->len + extra_head);
+ if ((hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) &&
+ ieee80211_amsdu_aggregate(sdata, sta, fast_tx, skb))
+ return true;
+
/* will not be crypto-handled beyond what we do here, so use false
* as the may-encrypt argument for the resize to not account for
* more room than we already have in 'extra_head'