ath10k: use msdu headroom to store txfrag
Instead of allocating sk_buff for a mere 16-byte
tx fragment list buffer use headroom of the
original msdu sk_buff.
This decreases CPU cache pressure and improves
performance.
Measured improvement on AP135 is 560mbps ->
590mbps of UDP TX briding traffic.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
diff --git a/drivers/net/wireless/ath/ath10k/htt_tx.c b/drivers/net/wireless/ath/ath10k/htt_tx.c
index 5e738d8..3b93c6a 100644
--- a/drivers/net/wireless/ath/ath10k/htt_tx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_tx.c
@@ -307,7 +307,8 @@
struct device *dev = htt->ar->dev;
struct sk_buff *txdesc = NULL;
struct htt_cmd *cmd;
- u8 vdev_id = ATH10K_SKB_CB(msdu)->htt.vdev_id;
+ struct ath10k_skb_cb *skb_cb = ATH10K_SKB_CB(msdu);
+ u8 vdev_id = skb_cb->htt.vdev_id;
int len = 0;
int msdu_id = -1;
int res;
@@ -350,6 +351,9 @@
memcpy(cmd->mgmt_tx.hdr, msdu->data,
min_t(int, msdu->len, HTT_MGMT_FRM_HDR_DOWNLOAD_LEN));
+ skb_cb->htt.frag_len = 0;
+ skb_cb->htt.pad_len = 0;
+
res = ath10k_htc_send(&htt->ar->htc, htt->eid, txdesc);
if (res)
goto err_unmap_msdu;
@@ -377,13 +381,12 @@
struct htt_cmd *cmd;
struct htt_data_tx_desc_frag *tx_frags;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)msdu->data;
+ struct ath10k_skb_cb *skb_cb = ATH10K_SKB_CB(msdu);
struct sk_buff *txdesc = NULL;
- struct sk_buff *txfrag = NULL;
bool use_frags;
u8 vdev_id = ATH10K_SKB_CB(msdu)->htt.vdev_id;
u8 tid;
- int prefetch_len, desc_len, frag_len;
- dma_addr_t frags_paddr;
+ int prefetch_len, desc_len;
int msdu_id = -1;
int res;
u8 flags0;
@@ -407,7 +410,6 @@
prefetch_len = roundup(prefetch_len, 4);
desc_len = sizeof(cmd->hdr) + sizeof(cmd->data_tx) + prefetch_len;
- frag_len = sizeof(*tx_frags) * 2;
txdesc = ath10k_htc_alloc_skb(desc_len);
if (!txdesc) {
@@ -421,41 +423,44 @@
use_frags = htt->target_version_major < 3 ||
!ieee80211_is_mgmt(hdr->frame_control);
- if (use_frags) {
- txfrag = dev_alloc_skb(frag_len);
- if (!txfrag) {
- res = -ENOMEM;
- goto err_free_txdesc;
- }
- }
-
if (!IS_ALIGNED((unsigned long)txdesc->data, 4)) {
ath10k_warn("htt alignment check failed. dropping packet.\n");
res = -EIO;
- goto err_free_txfrag;
+ goto err_free_txdesc;
+ }
+
+ if (use_frags) {
+ skb_cb->htt.frag_len = sizeof(*tx_frags) * 2;
+ skb_cb->htt.pad_len = (unsigned long)msdu->data -
+ round_down((unsigned long)msdu->data, 4);
+
+ skb_push(msdu, skb_cb->htt.frag_len + skb_cb->htt.pad_len);
+ } else {
+ skb_cb->htt.frag_len = 0;
+ skb_cb->htt.pad_len = 0;
}
res = ath10k_skb_map(dev, msdu);
if (res)
- goto err_free_txfrag;
+ goto err_pull_txfrag;
if (use_frags) {
+ dma_sync_single_for_cpu(dev, skb_cb->paddr, msdu->len,
+ DMA_TO_DEVICE);
+
/* tx fragment list must be terminated with zero-entry */
- skb_put(txfrag, frag_len);
- tx_frags = (struct htt_data_tx_desc_frag *)txfrag->data;
- tx_frags[0].paddr = __cpu_to_le32(ATH10K_SKB_CB(msdu)->paddr);
- tx_frags[0].len = __cpu_to_le32(msdu->len);
+ tx_frags = (struct htt_data_tx_desc_frag *)msdu->data;
+ tx_frags[0].paddr = __cpu_to_le32(skb_cb->paddr +
+ skb_cb->htt.frag_len +
+ skb_cb->htt.pad_len);
+ tx_frags[0].len = __cpu_to_le32(msdu->len -
+ skb_cb->htt.frag_len -
+ skb_cb->htt.pad_len);
tx_frags[1].paddr = __cpu_to_le32(0);
tx_frags[1].len = __cpu_to_le32(0);
- res = ath10k_skb_map(dev, txfrag);
- if (res)
- goto err_unmap_msdu;
-
- ath10k_dbg(ATH10K_DBG_HTT, "txfrag 0x%llx\n",
- (unsigned long long) ATH10K_SKB_CB(txfrag)->paddr);
- ath10k_dbg_dump(ATH10K_DBG_HTT_DUMP, NULL, "txfrag: ",
- txfrag->data, frag_len);
+ dma_sync_single_for_device(dev, skb_cb->paddr, msdu->len,
+ DMA_TO_DEVICE);
}
ath10k_dbg(ATH10K_DBG_HTT, "msdu 0x%llx\n",
@@ -488,35 +493,28 @@
flags1 |= HTT_DATA_TX_DESC_FLAGS1_CKSUM_L3_OFFLOAD;
flags1 |= HTT_DATA_TX_DESC_FLAGS1_CKSUM_L4_OFFLOAD;
- if (use_frags)
- frags_paddr = ATH10K_SKB_CB(txfrag)->paddr;
- else
- frags_paddr = ATH10K_SKB_CB(msdu)->paddr;
-
cmd->hdr.msg_type = HTT_H2T_MSG_TYPE_TX_FRM;
cmd->data_tx.flags0 = flags0;
cmd->data_tx.flags1 = __cpu_to_le16(flags1);
- cmd->data_tx.len = __cpu_to_le16(msdu->len);
+ cmd->data_tx.len = __cpu_to_le16(msdu->len -
+ skb_cb->htt.frag_len -
+ skb_cb->htt.pad_len);
cmd->data_tx.id = __cpu_to_le16(msdu_id);
- cmd->data_tx.frags_paddr = __cpu_to_le32(frags_paddr);
+ cmd->data_tx.frags_paddr = __cpu_to_le32(skb_cb->paddr);
cmd->data_tx.peerid = __cpu_to_le32(HTT_INVALID_PEERID);
- memcpy(cmd->data_tx.prefetch, msdu->data, prefetch_len);
+ memcpy(cmd->data_tx.prefetch, hdr, prefetch_len);
res = ath10k_htc_send(&htt->ar->htc, htt->eid, txdesc);
if (res)
- goto err_restore;
+ goto err_unmap_msdu;
return 0;
-err_restore:
- if (use_frags)
- ath10k_skb_unmap(dev, txfrag);
err_unmap_msdu:
ath10k_skb_unmap(dev, msdu);
-err_free_txfrag:
- if (use_frags)
- dev_kfree_skb_any(txfrag);
+err_pull_txfrag:
+ skb_pull(msdu, skb_cb->htt.frag_len + skb_cb->htt.pad_len);
err_free_txdesc:
dev_kfree_skb_any(txdesc);
err_free_msdu_id: