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Message-Id: <1439989181-4444-3-git-send-email-emmanuel.grumbach@intel.com>
Date: Wed, 19 Aug 2015 15:59:40 +0300
From: Emmanuel Grumbach <emmanuel.grumbach@...el.com>
To: linux-wireless@...r.kernel.org
Cc: ido@...ery.com, netdev@...r.kernel.org,
Emmanuel Grumbach <emmanuel.grumbach@...el.com>
Subject: [RFC v2 2/3] iwlwifi: mvm: allow to create A-MSDUs from a large send
Now that we can get a big chunk of data from the network
stack, we can create an A-MSDU out of it. The purpose is to
get a throughput improvement since sending one single A-MSDU
is more efficient than sending several MSDUs at least under
ideal link conditions.
type=feature
Change-Id: I5ea1b1132a57542187cd4c34c5299dbf44fe8b01
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@...el.com>
---
drivers/net/wireless/iwlwifi/mvm/mac80211.c | 3 +-
drivers/net/wireless/iwlwifi/mvm/sta.c | 4 +-
drivers/net/wireless/iwlwifi/mvm/sta.h | 6 +-
drivers/net/wireless/iwlwifi/mvm/tx.c | 159 ++++++++++++++++++++++++++--
4 files changed, 160 insertions(+), 12 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
index 3dd4e97..dd15e04 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -925,7 +925,8 @@ static int iwl_mvm_mac_ampdu_action(struct ieee80211_hw *hw,
ret = iwl_mvm_sta_tx_agg_flush(mvm, vif, sta, tid);
break;
case IEEE80211_AMPDU_TX_OPERATIONAL:
- ret = iwl_mvm_sta_tx_agg_oper(mvm, vif, sta, tid, buf_size);
+ ret = iwl_mvm_sta_tx_agg_oper(mvm, vif, sta, tid,
+ buf_size, amsdu);
break;
default:
WARN_ON_ONCE(1);
diff --git a/drivers/net/wireless/iwlwifi/mvm/sta.c b/drivers/net/wireless/iwlwifi/mvm/sta.c
index df216cd..606fc09 100644
--- a/drivers/net/wireless/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/iwlwifi/mvm/sta.c
@@ -976,7 +976,8 @@ int iwl_mvm_sta_tx_agg_start(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
}
int iwl_mvm_sta_tx_agg_oper(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
- struct ieee80211_sta *sta, u16 tid, u8 buf_size)
+ struct ieee80211_sta *sta, u16 tid, u8 buf_size,
+ bool amsdu)
{
struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
struct iwl_mvm_tid_data *tid_data = &mvmsta->tid_data[tid];
@@ -995,6 +996,7 @@ int iwl_mvm_sta_tx_agg_oper(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
queue = tid_data->txq_id;
tid_data->state = IWL_AGG_ON;
mvmsta->agg_tids |= BIT(tid);
+ tid_data->amsdu_in_ampdu_allowed = amsdu;
tid_data->ssn = 0xffff;
spin_unlock_bh(&mvmsta->lock);
diff --git a/drivers/net/wireless/iwlwifi/mvm/sta.h b/drivers/net/wireless/iwlwifi/mvm/sta.h
index eedb215..26d1e31 100644
--- a/drivers/net/wireless/iwlwifi/mvm/sta.h
+++ b/drivers/net/wireless/iwlwifi/mvm/sta.h
@@ -258,6 +258,8 @@ enum iwl_mvm_agg_state {
* Tx response (TX_CMD), and the block ack notification (COMPRESSED_BA).
* @reduced_tpc: Reduced tx power. Holds the data between the
* Tx response (TX_CMD), and the block ack notification (COMPRESSED_BA).
+ * @amsdu_in_ampdu_allowed: true if A-MSDU in A-MPDU is allowed. Relevant only
+ * if &state is %IWL_AGG_ON.
* @state: state of the BA agreement establishment / tear down.
* @txq_id: Tx queue used by the BA session
* @ssn: the first packet to be sent in AGG HW queue in Tx AGG start flow, or
@@ -272,6 +274,7 @@ struct iwl_mvm_tid_data {
/* The rest is Tx AGG related */
u32 rate_n_flags;
u8 reduced_tpc;
+ bool amsdu_in_ampdu_allowed;
enum iwl_mvm_agg_state state;
u16 txq_id;
u16 ssn;
@@ -387,7 +390,8 @@ int iwl_mvm_sta_rx_agg(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
int iwl_mvm_sta_tx_agg_start(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
struct ieee80211_sta *sta, u16 tid, u16 *ssn);
int iwl_mvm_sta_tx_agg_oper(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
- struct ieee80211_sta *sta, u16 tid, u8 buf_size);
+ struct ieee80211_sta *sta, u16 tid, u8 buf_size,
+ bool amsdu);
int iwl_mvm_sta_tx_agg_stop(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
struct ieee80211_sta *sta, u16 tid);
int iwl_mvm_sta_tx_agg_flush(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
diff --git a/drivers/net/wireless/iwlwifi/mvm/tx.c b/drivers/net/wireless/iwlwifi/mvm/tx.c
index a63686c..5046833 100644
--- a/drivers/net/wireless/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/iwlwifi/mvm/tx.c
@@ -488,8 +488,10 @@ static void iwl_update_ip_tcph(void *iph, struct tcphdr *tcph, bool ipv6,
* @ieee80211_hdr *hdr: Points to the WiFi header.
* @gso_nr_frags: The number of frags in the original GSO skb.
* @wifi_hdr_iv_len: The length of the WiFi header including IV.
+ * @amsdu_pad: Number of bytes for the A-MSDU subframe
* @tcp_fin: True if TCP_FIN is set in the original GSO skb.
* @tcp_push: True if TCP_PSH is set in the original GSO skb.
+ * @amsdu: True if we are building an A-MSDU
*/
struct iwl_lso_splitter {
unsigned int linear_payload_len;
@@ -505,8 +507,10 @@ struct iwl_lso_splitter {
struct ieee80211_hdr *hdr;
u8 gso_nr_frags;
u8 wifi_hdr_iv_len;
+ u8 amsdu_pad;
bool tcp_fin;
bool tcp_push;
+ bool amsdu;
};
/*
@@ -621,9 +625,10 @@ static int iwl_add_msdu(struct iwl_mvm *mvm, struct sk_buff *skb_gso,
u8 **hdr_page_pos, int ip_id,
struct iwl_lso_splitter *p)
{
- unsigned int tcp_seg_sz, snap_ip_tcp_len, copy_sz = 0;
+ unsigned int tcp_seg_sz, snap_ip_tcp_len, subframe_sz, copy_sz = 0;
bool ipv6 = p->si->gso_type & SKB_GSO_TCPV6;
u8 *start_hdr;
+ __be16 *length = NULL;
struct tcphdr *tcph;
struct iphdr *iph;
@@ -640,6 +645,45 @@ static int iwl_add_msdu(struct iwl_mvm *mvm, struct sk_buff *skb_gso,
start_hdr = *hdr_page_pos;
+ subframe_sz = snap_ip_tcp_len;
+
+ if (p->amsdu) {
+ memset(*hdr_page_pos, 0, p->amsdu_pad);
+ *hdr_page_pos += p->amsdu_pad;
+ switch (p->hdr->frame_control &
+ cpu_to_le16(IEEE80211_FCTL_TODS |
+ IEEE80211_FCTL_FROMDS)) {
+ /* STA */
+ case cpu_to_le16(IEEE80211_FCTL_TODS):
+ memcpy(*hdr_page_pos, p->hdr->addr3, ETH_ALEN);
+ *hdr_page_pos += ETH_ALEN;
+
+ memcpy(*hdr_page_pos, p->hdr->addr2, ETH_ALEN);
+ *hdr_page_pos += ETH_ALEN;
+ break;
+ /* AP */
+ case cpu_to_le16(IEEE80211_FCTL_FROMDS):
+ memcpy(*hdr_page_pos, p->hdr->addr1, ETH_ALEN);
+ *hdr_page_pos += ETH_ALEN;
+
+ memcpy(*hdr_page_pos, p->hdr->addr3, ETH_ALEN);
+ *hdr_page_pos += ETH_ALEN;
+ break;
+ /* TDLS or IBSS */
+ case cpu_to_le16(0):
+ memcpy(*hdr_page_pos, p->hdr->addr1, ETH_ALEN);
+ *hdr_page_pos += ETH_ALEN;
+
+ memcpy(*hdr_page_pos, p->hdr->addr2, ETH_ALEN);
+ *hdr_page_pos += ETH_ALEN;
+ break;
+ }
+
+ length = (void *)*hdr_page_pos;
+ *hdr_page_pos += sizeof(*length);
+ subframe_sz += sizeof(struct ethhdr);
+ }
+
/*
* Copy SNAP / IP / TCP headers from the original GSO skb to the
* header page.
@@ -681,6 +725,11 @@ static int iwl_add_msdu(struct iwl_mvm *mvm, struct sk_buff *skb_gso,
/* .. and now add the payload coming from the frags. */
tcp_seg_sz = iwl_add_tcp_segment(mvm, skb_gso, skb, p, copy_sz);
+ subframe_sz += tcp_seg_sz;
+ p->amsdu_pad = (4 - (subframe_sz)) & 0x3;
+
+ if (length)
+ *length = cpu_to_be16(subframe_sz - sizeof(struct ethhdr));
iwl_update_ip_tcph(iph, tcph, ipv6, tcp_seg_sz,
p->gso_payload_pos - tcp_seg_sz, ip_id);
@@ -701,13 +750,14 @@ static int iwl_add_msdu(struct iwl_mvm *mvm, struct sk_buff *skb_gso,
tcp_seg_sz,
tcp_hdrlen(skb_gso));
- return 0;
+ return subframe_sz;
}
static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb_gso,
struct ieee80211_sta *sta,
struct sk_buff_head *mpdus_skb)
{
+ struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb_gso);
struct ieee80211_key_conf *keyconf = info->control.hw_key;
struct ieee80211_hdr *wifi_hdr = (void *)skb_gso->data;
@@ -715,7 +765,7 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb_gso,
struct iwl_lso_splitter s = {};
struct page *hdr_page;
unsigned int mpdu_sz;
- u8 *hdr_page_pos;
+ u8 *hdr_page_pos, *qc, tid;
int i, ret;
s.si = skb_shinfo(skb_gso);
@@ -864,9 +914,22 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb_gso,
keyconf->cipher == WLAN_CIPHER_SUITE_CCMP_256))
s.wifi_hdr_iv_len += IEEE80211_CCMP_HDR_LEN;
+ qc = ieee80211_get_qos_ctl(s.hdr);
+ tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
+ if (WARN_ON_ONCE(tid >= IWL_MAX_TID_COUNT)) {
+ ret = -1;
+ goto out;
+ }
+
+ spin_lock(&mvmsta->lock);
+ s.amsdu = !(info->flags & IEEE80211_TX_CTL_AMPDU) ||
+ mvmsta->tid_data[tid].amsdu_in_ampdu_allowed;
+
+ spin_unlock(&mvmsta->lock);
+
while (s.gso_payload_pos < s.gso_payload_len) {
struct sk_buff *skb = dev_alloc_skb(s.wifi_hdr_iv_len);
- int l;
+ unsigned int ip_tcp_snap_hdrlen, amsdu_sz, max_amsdu_len;
s.frag_in_mpdu = 0;
@@ -884,14 +947,92 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb_gso,
memcpy(skb_put(skb, s.wifi_hdr_iv_len),
wifi_hdr, s.wifi_hdr_iv_len);
- l = iwl_add_msdu(mvm, skb_gso, skb, &hdr_page,
- &hdr_page_pos, i++, &s);
- if (l < 0) {
- skb_queue_purge(mpdus_skb);
- ret = l;
+ /* No need to have an AMSDU if we have at most mss bytes */
+ if (s.gso_payload_len - s.gso_payload_pos <= s.mss)
+ s.amsdu = false;
+
+ /*
+ * Limit A-MSDU in A-MPDU to 4095 bytes when VHT is not
+ * supported. This is a spec requirement (IEEE 802.11-2015
+ * section 8.7.3 NOTE 3).
+ */
+ if (info->flags & IEEE80211_TX_CTL_AMPDU &&
+ mvmsta->tid_data[tid].amsdu_in_ampdu_allowed &&
+ !sta->vht_cap.vht_supported)
+ max_amsdu_len = 4095;
+ else
+ max_amsdu_len = 0;
+
+ if (max_amsdu_len)
+ max_amsdu_len = min_t(unsigned int, sta->max_amsdu_len,
+ max_amsdu_len);
+ else
+ max_amsdu_len = sta->max_amsdu_len;
+
+ /*
+ * Technically, this will allow to have an A-MSDU will only
+ * one subframe. But this won't happen on valid limits. Only
+ * on custom limit set by debugfs. We could test that there is
+ * enough room for the subframe header + data headers etc...
+ * but these tests cost, and this is a hot path.
+ */
+ if (!max_amsdu_len || !s.amsdu) {
+ int l;
+
+ s.amsdu = false;
+ l = iwl_add_msdu(mvm, skb_gso, skb, &hdr_page,
+ &hdr_page_pos, i++, &s);
+ if (l < 0) {
+ skb_queue_purge(mpdus_skb);
+ ret = l;
+ goto out;
+ }
+
+ __skb_queue_tail(mpdus_skb, skb);
+ continue;
+ }
+
+ if (WARN_ON_ONCE(max_amsdu_len < s.mss)) {
+ ret = -1;
goto out;
}
+ qc = ieee80211_get_qos_ctl((void *)skb->data);
+ *qc |= IEEE80211_QOS_CTL_A_MSDU_PRESENT;
+
+ amsdu_sz = 0;
+ s.amsdu_pad = 0;
+ ip_tcp_snap_hdrlen =
+ 8 + ip_hdrlen(skb_gso) + tcp_hdrlen(skb_gso);
+
+ i = 0;
+
+ /*
+ * Make sure we have enough room for
+ * ethernet header, SNAP header, IP header, TCP header and MSS.
+ * Make sure we don't add more MSDUs than allowed
+ */
+ while (amsdu_sz + sizeof(struct ethhdr) + s.mss +
+ ip_tcp_snap_hdrlen < max_amsdu_len &&
+ (!sta->max_amsdu_subframes ||
+ i < sta->max_amsdu_subframes) &&
+ s.gso_payload_pos < s.gso_payload_len) {
+ unsigned int l;
+
+ if (s.frag_in_mpdu + 1 >= mvm->trans->max_skb_frags)
+ break;
+
+ l = iwl_add_msdu(mvm, skb_gso, skb, &hdr_page,
+ &hdr_page_pos, i++, &s);
+ if (l < 0) {
+ skb_queue_purge(mpdus_skb);
+ ret = l;
+ goto out;
+ }
+
+ amsdu_sz += l + s.amsdu_pad;
+ }
+
__skb_queue_tail(mpdus_skb, skb);
}
--
2.1.4
--
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