-From: Felix Fietkau <nbd@nbd.name>
-Date: Sun, 9 Oct 2022 20:15:46 +0200
-Subject: [PATCH] mac80211: add support for restricting netdev features per vif
-
-This can be used to selectively disable feature flags for checksum offload,
-scatter/gather or GSO by changing vif->netdev_features.
-Removing features from vif->netdev_features does not affect the netdev
-features themselves, but instead fixes up skbs in the tx path so that the
-offloads are not needed in the driver.
-
-Aside from making it easier to deal with vif type based hardware limitations,
-this also makes it possible to optimize performance on hardware without native
-GSO support by declaring GSO support in hw->netdev_features and removing it
-from vif->netdev_features. This allows mac80211 to handle GSO segmentation
-after the sta lookup, but before itxq enqueue, thus reducing the number of
-unnecessary sta lookups, as well as some other per-packet processing.
-
-Signed-off-by: Felix Fietkau <nbd@nbd.name>
----
-
---- a/include/net/fq_impl.h
-+++ b/include/net/fq_impl.h
-@@ -200,6 +200,7 @@ static void fq_tin_enqueue(struct fq *fq
- fq_skb_free_t free_func)
- {
- struct fq_flow *flow;
-+ struct sk_buff *next;
- bool oom;
-
- lockdep_assert_held(&fq->lock);
-@@ -214,11 +215,15 @@ static void fq_tin_enqueue(struct fq *fq
- }
-
- flow->tin = tin;
-- flow->backlog += skb->len;
-- tin->backlog_bytes += skb->len;
-- tin->backlog_packets++;
-- fq->memory_usage += skb->truesize;
-- fq->backlog++;
-+ skb_list_walk_safe(skb, skb, next) {
-+ skb_mark_not_on_list(skb);
-+ flow->backlog += skb->len;
-+ tin->backlog_bytes += skb->len;
-+ tin->backlog_packets++;
-+ fq->memory_usage += skb->truesize;
-+ fq->backlog++;
-+ __skb_queue_tail(&flow->queue, skb);
-+ }
-
- if (list_empty(&flow->flowchain)) {
- flow->deficit = fq->quantum;
-@@ -226,7 +231,6 @@ static void fq_tin_enqueue(struct fq *fq
- &tin->new_flows);
- }
-
-- __skb_queue_tail(&flow->queue, skb);
- oom = (fq->memory_usage > fq->memory_limit);
- while (fq->backlog > fq->limit || oom) {
- flow = fq_find_fattest_flow(fq);
---- a/include/net/mac80211.h
-+++ b/include/net/mac80211.h
-@@ -1685,6 +1685,10 @@ enum ieee80211_offload_flags {
- * write-protected by sdata_lock and local->mtx so holding either is fine
- * for read access.
- * @mu_mimo_owner: indicates interface owns MU-MIMO capability
-+ * @netdev_features: tx netdev features supported by the hardware for this
-+ * vif. mac80211 initializes this to hw->netdev_features, and the driver
-+ * can mask out specific tx features. mac80211 will handle software fixup
-+ * for masked offloads (GSO, CSUM)
- * @driver_flags: flags/capabilities the driver has for this interface,
- * these need to be set (or cleared) when the interface is added
- * or, if supported by the driver, the interface type is changed
-@@ -1736,6 +1740,7 @@ struct ieee80211_vif {
-
- struct ieee80211_chanctx_conf __rcu *chanctx_conf;
-
-+ netdev_features_t netdev_features;
- u32 driver_flags;
- u32 offload_flags;
-
---- a/net/mac80211/iface.c
-+++ b/net/mac80211/iface.c
-@@ -2209,6 +2209,7 @@ int ieee80211_if_add(struct ieee80211_lo
- ndev->features |= local->hw.netdev_features;
- ndev->hw_features |= ndev->features &
- MAC80211_SUPPORTED_FEATURES_TX;
-+ sdata->vif.netdev_features = local->hw.netdev_features;
-
- netdev_set_default_ethtool_ops(ndev, &ieee80211_ethtool_ops);
-
---- a/net/mac80211/tx.c
-+++ b/net/mac80211/tx.c
-@@ -1310,7 +1310,11 @@ static struct txq_info *ieee80211_get_tx
-
- static void ieee80211_set_skb_enqueue_time(struct sk_buff *skb)
- {
-- IEEE80211_SKB_CB(skb)->control.enqueue_time = codel_get_time();
-+ struct sk_buff *next;
-+ codel_time_t now = codel_get_time();
-+
-+ skb_list_walk_safe(skb, skb, next)
-+ IEEE80211_SKB_CB(skb)->control.enqueue_time = now;
- }
-
- static u32 codel_skb_len_func(const struct sk_buff *skb)
-@@ -3499,47 +3503,71 @@ ieee80211_xmit_fast_finish(struct ieee80
- return TX_CONTINUE;
- }
-
--static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
-- struct sta_info *sta,
-- struct ieee80211_fast_tx *fast_tx,
-- struct sk_buff *skb)
-+static netdev_features_t
-+ieee80211_sdata_netdev_features(struct ieee80211_sub_if_data *sdata)
- {
-- struct ieee80211_local *local = sdata->local;
-- u16 ethertype = (skb->data[12] << 8) | skb->data[13];
-- int extra_head = fast_tx->hdr_len - (ETH_HLEN - 2);
-- int hw_headroom = sdata->local->hw.extra_tx_headroom;
-- struct ethhdr eth;
-- struct ieee80211_tx_info *info;
-- struct ieee80211_hdr *hdr = (void *)fast_tx->hdr;
-- struct ieee80211_tx_data tx;
-- ieee80211_tx_result r;
-- struct tid_ampdu_tx *tid_tx = NULL;
-- u8 tid = IEEE80211_NUM_TIDS;
-+ if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
-+ return sdata->vif.netdev_features;
-
-- /* control port protocol needs a lot of special handling */
-- if (cpu_to_be16(ethertype) == sdata->control_port_protocol)
-- return false;
-+ if (!sdata->bss)
-+ return 0;
-
-- /* only RFC 1042 SNAP */
-- if (ethertype < ETH_P_802_3_MIN)
-- return false;
-+ sdata = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
-+ return sdata->vif.netdev_features;
-+}
-
-- /* don't handle TX status request here either */
-- if (skb->sk && skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)
-- return false;
-+static struct sk_buff *
-+ieee80211_tx_skb_fixup(struct sk_buff *skb, netdev_features_t features)
-+{
-+ if (skb_is_gso(skb)) {
-+ struct sk_buff *segs;
-
-- if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
-- tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
-- tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
-- if (tid_tx) {
-- if (!test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state))
-- return false;
-- if (tid_tx->timeout)
-- tid_tx->last_tx = jiffies;
-- }
-+ segs = skb_gso_segment(skb, features);
-+ if (!segs)
-+ return skb;
-+ if (IS_ERR(segs))
-+ goto free;
-+
-+ consume_skb(skb);
-+ return segs;
-+ }
-+
-+ if (skb_needs_linearize(skb, features) && __skb_linearize(skb))
-+ goto free;
-+
-+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
-+ int ofs = skb_checksum_start_offset(skb);
-+
-+ if (skb->encapsulation)
-+ skb_set_inner_transport_header(skb, ofs);
-+ else
-+ skb_set_transport_header(skb, ofs);
-+
-+ if (skb_csum_hwoffload_help(skb, features))
-+ goto free;
- }
-
-- /* after this point (skb is modified) we cannot return false */
-+ skb_mark_not_on_list(skb);
-+ return skb;
-+
-+free:
-+ kfree_skb(skb);
-+ return NULL;
-+}
-+
-+static void __ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
-+ struct sta_info *sta,
-+ struct ieee80211_fast_tx *fast_tx,
-+ struct sk_buff *skb, u8 tid, bool ampdu)
-+{
-+ struct ieee80211_local *local = sdata->local;
-+ struct ieee80211_hdr *hdr = (void *)fast_tx->hdr;
-+ struct ieee80211_tx_info *info;
-+ struct ieee80211_tx_data tx;
-+ ieee80211_tx_result r;
-+ int hw_headroom = sdata->local->hw.extra_tx_headroom;
-+ int extra_head = fast_tx->hdr_len - (ETH_HLEN - 2);
-+ struct ethhdr eth;
-
- if (skb_shared(skb)) {
- struct sk_buff *tmp_skb = skb;
-@@ -3548,12 +3576,12 @@ static bool ieee80211_xmit_fast(struct i
- kfree_skb(tmp_skb);
-
- if (!skb)
-- return true;
-+ return;
- }
-
- if ((hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) &&
- ieee80211_amsdu_aggregate(sdata, sta, fast_tx, skb))
-- return true;
-+ return;
-
- /* 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
-@@ -3562,10 +3590,8 @@ static bool ieee80211_xmit_fast(struct i
- if (unlikely(ieee80211_skb_resize(sdata, skb,
- max_t(int, extra_head + hw_headroom -
- skb_headroom(skb), 0),
-- ENCRYPT_NO))) {
-- kfree_skb(skb);
-- return true;
-- }
-+ ENCRYPT_NO)))
-+ goto free;
-
- memcpy(ð, skb->data, ETH_HLEN - 2);
- hdr = skb_push(skb, extra_head);
-@@ -3579,7 +3605,7 @@ static bool ieee80211_xmit_fast(struct i
- info->control.vif = &sdata->vif;
- info->flags = IEEE80211_TX_CTL_FIRST_FRAGMENT |
- IEEE80211_TX_CTL_DONTFRAG |
-- (tid_tx ? IEEE80211_TX_CTL_AMPDU : 0);
-+ (ampdu ? IEEE80211_TX_CTL_AMPDU : 0);
- info->control.flags = IEEE80211_TX_CTRL_FAST_XMIT;
-
- #ifdef CPTCFG_MAC80211_DEBUGFS
-@@ -3601,16 +3627,14 @@ static bool ieee80211_xmit_fast(struct i
- tx.key = fast_tx->key;
-
- if (ieee80211_queue_skb(local, sdata, sta, skb))
-- return true;
-+ return;
-
- tx.skb = skb;
- r = ieee80211_xmit_fast_finish(sdata, sta, fast_tx->pn_offs,
- fast_tx->key, &tx);
- tx.skb = NULL;
-- if (r == TX_DROP) {
-- kfree_skb(skb);
-- return true;
-- }
-+ if (r == TX_DROP)
-+ goto free;
-
- if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
- sdata = container_of(sdata->bss,
-@@ -3618,6 +3642,55 @@ static bool ieee80211_xmit_fast(struct i
-
- __skb_queue_tail(&tx.skbs, skb);
- ieee80211_tx_frags(local, &sdata->vif, sta, &tx.skbs, false);
-+ return;
-+
-+free:
-+ kfree_skb(skb);
-+}
-+
-+static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
-+ struct sta_info *sta,
-+ struct ieee80211_fast_tx *fast_tx,
-+ struct sk_buff *skb)
-+{
-+ u16 ethertype = (skb->data[12] << 8) | skb->data[13];
-+ struct ieee80211_hdr *hdr = (void *)fast_tx->hdr;
-+ struct tid_ampdu_tx *tid_tx = NULL;
-+ struct sk_buff *next;
-+ u8 tid = IEEE80211_NUM_TIDS;
-+
-+ /* control port protocol needs a lot of special handling */
-+ if (cpu_to_be16(ethertype) == sdata->control_port_protocol)
-+ return false;
-+
-+ /* only RFC 1042 SNAP */
-+ if (ethertype < ETH_P_802_3_MIN)
-+ return false;
-+
-+ /* don't handle TX status request here either */
-+ if (skb->sk && skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)
-+ return false;
-+
-+ if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
-+ tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
-+ tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
-+ if (tid_tx) {
-+ if (!test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state))
-+ return false;
-+ if (tid_tx->timeout)
-+ tid_tx->last_tx = jiffies;
-+ }
-+ }
-+
-+ skb = ieee80211_tx_skb_fixup(skb, ieee80211_sdata_netdev_features(sdata));
-+ if (!skb)
-+ return true;
-+
-+ skb_list_walk_safe(skb, skb, next) {
-+ skb_mark_not_on_list(skb);
-+ __ieee80211_xmit_fast(sdata, sta, fast_tx, skb, tid, tid_tx);
-+ }
-+
- return true;
- }
-
-@@ -4123,31 +4196,14 @@ void __ieee80211_subif_start_xmit(struct
- goto out;
- }
-
-- if (skb_is_gso(skb)) {
-- struct sk_buff *segs;
--
-- segs = skb_gso_segment(skb, 0);
-- if (IS_ERR(segs)) {
-- goto out_free;
-- } else if (segs) {
-- consume_skb(skb);
-- skb = segs;
-- }
-- } else {
-- /* we cannot process non-linear frames on this path */
-- if (skb_linearize(skb))
-- goto out_free;
--
-- /* the frame could be fragmented, software-encrypted, and other
-- * things so we cannot really handle checksum offload with it -
-- * fix it up in software before we handle anything else.
-- */
-- if (skb->ip_summed == CHECKSUM_PARTIAL) {
-- skb_set_transport_header(skb,
-- skb_checksum_start_offset(skb));
-- if (skb_checksum_help(skb))
-- goto out_free;
-- }
-+ /* the frame could be fragmented, software-encrypted, and other
-+ * things so we cannot really handle checksum or GSO offload.
-+ * fix it up in software before we handle anything else.
-+ */
-+ skb = ieee80211_tx_skb_fixup(skb, 0);
-+ if (!skb) {
-+ len = 0;
-+ goto out;
- }
-
- skb_list_walk_safe(skb, skb, next) {
-@@ -4310,9 +4366,11 @@ netdev_tx_t ieee80211_subif_start_xmit(s
- return NETDEV_TX_OK;
- }
-
--static bool ieee80211_tx_8023(struct ieee80211_sub_if_data *sdata,
-- struct sk_buff *skb, struct sta_info *sta,
-- bool txpending)
-+
-+
-+static bool __ieee80211_tx_8023(struct ieee80211_sub_if_data *sdata,
-+ struct sk_buff *skb, struct sta_info *sta,
-+ bool txpending)
- {
- struct ieee80211_local *local = sdata->local;
- struct ieee80211_tx_control control = {};
-@@ -4321,14 +4379,6 @@ static bool ieee80211_tx_8023(struct iee
- unsigned long flags;
- int q = info->hw_queue;
-
-- if (sta)
-- sk_pacing_shift_update(skb->sk, local->hw.tx_sk_pacing_shift);
--
-- ieee80211_tpt_led_trig_tx(local, skb->len);
--
-- if (ieee80211_queue_skb(local, sdata, sta, skb))
-- return true;
--
- spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
-
- if (local->queue_stop_reasons[q] ||
-@@ -4355,27 +4405,50 @@ static bool ieee80211_tx_8023(struct iee
- return true;
- }
-
-+static bool ieee80211_tx_8023(struct ieee80211_sub_if_data *sdata,
-+ struct sk_buff *skb, struct sta_info *sta,
-+ bool txpending)
-+{
-+ struct ieee80211_local *local = sdata->local;
-+ struct sk_buff *next;
-+ bool ret = true;
-+
-+ if (ieee80211_queue_skb(local, sdata, sta, skb))
-+ return true;
-+
-+ skb_list_walk_safe(skb, skb, next) {
-+ skb_mark_not_on_list(skb);
-+ if (!__ieee80211_tx_8023(sdata, skb, sta, txpending))
-+ ret = false;
-+ }
-+
-+ return ret;
-+}
-+
- static void ieee80211_8023_xmit(struct ieee80211_sub_if_data *sdata,
- struct net_device *dev, struct sta_info *sta,
- struct ieee80211_key *key, struct sk_buff *skb)
- {
-- struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-+ struct ieee80211_tx_info *info;
- struct ieee80211_local *local = sdata->local;
- struct tid_ampdu_tx *tid_tx;
-+ struct sk_buff *seg, *next;
-+ unsigned int skbs = 0, len = 0;
-+ u16 queue;
- u8 tid;
-
- if (local->ops->wake_tx_queue) {
-- u16 queue = __ieee80211_select_queue(sdata, sta, skb);
-+ queue = __ieee80211_select_queue(sdata, sta, skb);
- skb_set_queue_mapping(skb, queue);
- skb_get_hash(skb);
-+ } else {
-+ queue = skb_get_queue_mapping(skb);
- }
-
- if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning)) &&
- test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))
- goto out_free;
-
-- memset(info, 0, sizeof(*info));
--
- ieee80211_aggr_check(sdata, sta, skb);
-
- tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
-@@ -4387,22 +4460,20 @@ static void ieee80211_8023_xmit(struct i
- return;
- }
-
-- info->flags |= IEEE80211_TX_CTL_AMPDU;
- if (tid_tx->timeout)
- tid_tx->last_tx = jiffies;
- }
-
-- if (unlikely(skb->sk &&
-- skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS))
-- info->ack_frame_id = ieee80211_store_ack_skb(local, skb,
-- &info->flags, NULL);
-+ skb = ieee80211_tx_skb_fixup(skb, ieee80211_sdata_netdev_features(sdata));
-+ if (!skb)
-+ return;
-
-- info->hw_queue = sdata->vif.hw_queue[skb_get_queue_mapping(skb)];
-+ info = IEEE80211_SKB_CB(skb);
-+ memset(info, 0, sizeof(*info));
-+ if (tid_tx)
-+ info->flags |= IEEE80211_TX_CTL_AMPDU;
-
-- dev_sw_netstats_tx_add(dev, 1, skb->len);
--
-- sta->tx_stats.bytes[skb_get_queue_mapping(skb)] += skb->len;
-- sta->tx_stats.packets[skb_get_queue_mapping(skb)]++;
-+ info->hw_queue = sdata->vif.hw_queue[queue];
-
- if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
- sdata = container_of(sdata->bss,
-@@ -4414,6 +4485,24 @@ static void ieee80211_8023_xmit(struct i
- if (key)
- info->control.hw_key = &key->conf;
-
-+ skb_list_walk_safe(skb, seg, next) {
-+ skbs++;
-+ len += seg->len;
-+ if (seg != skb)
-+ memcpy(IEEE80211_SKB_CB(seg), info, sizeof(*info));
-+ }
-+
-+ if (unlikely(skb->sk &&
-+ skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS))
-+ info->ack_frame_id = ieee80211_store_ack_skb(local, skb,
-+ &info->flags, NULL);
-+
-+ dev_sw_netstats_tx_add(dev, skbs, len);
-+ sta->tx_stats.packets[queue] += skbs;
-+ sta->tx_stats.bytes[queue] += len;
-+
-+ ieee80211_tpt_led_trig_tx(local, len);
-+
- ieee80211_tx_8023(sdata, skb, sta, false);
-
- return;
-@@ -4455,6 +4544,7 @@ netdev_tx_t ieee80211_subif_start_xmit_8
- key->conf.cipher == WLAN_CIPHER_SUITE_TKIP))
- goto skip_offload;
-
-+ sk_pacing_shift_update(skb->sk, sdata->local->hw.tx_sk_pacing_shift);
- ieee80211_8023_xmit(sdata, dev, sta, key, skb);
- goto out;
-
projects / openwrt / openwrt.git / blobdiff