1 files changed, 869 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/ipoib_tx.c b/drivers/infiniband/hw/hfi1/ipoib_tx.c
new file mode 100644
index 000000000..188048468
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/ipoib_tx.c
@@ -0,0 +1,869 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/*
+ * Copyright(c) 2020 Intel Corporation.
+ *
+ */
+
+/*
+ * This file contains HFI1 support for IPOIB SDMA functionality
+ */
+
+#include <linux/log2.h>
+#include <linux/circ_buf.h>
+
+#include "sdma.h"
+#include "verbs.h"
+#include "trace_ibhdrs.h"
+#include "ipoib.h"
+#include "trace_tx.h"
+
+/* Add a convenience helper */
+#define CIRC_ADD(val, add, size) (((val) + (add)) & ((size) - 1))
+#define CIRC_NEXT(val, size) CIRC_ADD(val, 1, size)
+#define CIRC_PREV(val, size) CIRC_ADD(val, -1, size)
+
+/**
+ * struct ipoib_txreq - IPOIB transmit descriptor
+ * @txreq: sdma transmit request
+ * @sdma_hdr: 9b ib headers
+ * @sdma_status: status returned by sdma engine
+ * @priv: ipoib netdev private data
+ * @txq: txq on which skb was output
+ * @skb: skb to send
+ */
+struct ipoib_txreq {
+	struct sdma_txreq           txreq;
+	struct hfi1_sdma_header     sdma_hdr;
+	int                         sdma_status;
+	struct hfi1_ipoib_dev_priv *priv;
+	struct hfi1_ipoib_txq      *txq;
+	struct sk_buff             *skb;
+};
+
+struct ipoib_txparms {
+	struct hfi1_devdata        *dd;
+	struct rdma_ah_attr        *ah_attr;
+	struct hfi1_ibport         *ibp;
+	struct hfi1_ipoib_txq      *txq;
+	union hfi1_ipoib_flow       flow;
+	u32                         dqpn;
+	u8                          hdr_dwords;
+	u8                          entropy;
+};
+
+static u64 hfi1_ipoib_txreqs(const u64 sent, const u64 completed)
+{
+	return sent - completed;
+}
+
+static u64 hfi1_ipoib_used(struct hfi1_ipoib_txq *txq)
+{
+	return hfi1_ipoib_txreqs(txq->sent_txreqs,
+				 atomic64_read(&txq->complete_txreqs));
+}
+
+static void hfi1_ipoib_stop_txq(struct hfi1_ipoib_txq *txq)
+{
+	trace_hfi1_txq_stop(txq);
+	if (atomic_inc_return(&txq->stops) == 1)
+		netif_stop_subqueue(txq->priv->netdev, txq->q_idx);
+}
+
+static void hfi1_ipoib_wake_txq(struct hfi1_ipoib_txq *txq)
+{
+	trace_hfi1_txq_wake(txq);
+	if (atomic_dec_and_test(&txq->stops))
+		netif_wake_subqueue(txq->priv->netdev, txq->q_idx);
+}
+
+static uint hfi1_ipoib_ring_hwat(struct hfi1_ipoib_txq *txq)
+{
+	return min_t(uint, txq->priv->netdev->tx_queue_len,
+		     txq->tx_ring.max_items - 1);
+}
+
+static uint hfi1_ipoib_ring_lwat(struct hfi1_ipoib_txq *txq)
+{
+	return min_t(uint, txq->priv->netdev->tx_queue_len,
+		     txq->tx_ring.max_items) >> 1;
+}
+
+static void hfi1_ipoib_check_queue_depth(struct hfi1_ipoib_txq *txq)
+{
+	++txq->sent_txreqs;
+	if (hfi1_ipoib_used(txq) >= hfi1_ipoib_ring_hwat(txq) &&
+	    !atomic_xchg(&txq->ring_full, 1)) {
+		trace_hfi1_txq_full(txq);
+		hfi1_ipoib_stop_txq(txq);
+	}
+}
+
+static void hfi1_ipoib_check_queue_stopped(struct hfi1_ipoib_txq *txq)
+{
+	struct net_device *dev = txq->priv->netdev;
+
+	/* If shutting down just return as queue state is irrelevant */
+	if (unlikely(dev->reg_state != NETREG_REGISTERED))
+		return;
+
+	/*
+	 * When the queue has been drained to less than half full it will be
+	 * restarted.
+	 * The size of the txreq ring is fixed at initialization.
+	 * The tx queue len can be adjusted upward while the interface is
+	 * running.
+	 * The tx queue len can be large enough to overflow the txreq_ring.
+	 * Use the minimum of the current tx_queue_len or the rings max txreqs
+	 * to protect against ring overflow.
+	 */
+	if (hfi1_ipoib_used(txq) < hfi1_ipoib_ring_lwat(txq) &&
+	    atomic_xchg(&txq->ring_full, 0)) {
+		trace_hfi1_txq_xmit_unstopped(txq);
+		hfi1_ipoib_wake_txq(txq);
+	}
+}
+
+static void hfi1_ipoib_free_tx(struct ipoib_txreq *tx, int budget)
+{
+	struct hfi1_ipoib_dev_priv *priv = tx->priv;
+
+	if (likely(!tx->sdma_status)) {
+		hfi1_ipoib_update_tx_netstats(priv, 1, tx->skb->len);
+	} else {
+		++priv->netdev->stats.tx_errors;
+		dd_dev_warn(priv->dd,
+			    "%s: Status = 0x%x pbc 0x%llx txq = %d sde = %d\n",
+			    __func__, tx->sdma_status,
+			    le64_to_cpu(tx->sdma_hdr.pbc), tx->txq->q_idx,
+			    tx->txq->sde->this_idx);
+	}
+
+	napi_consume_skb(tx->skb, budget);
+	sdma_txclean(priv->dd, &tx->txreq);
+	kmem_cache_free(priv->txreq_cache, tx);
+}
+
+static int hfi1_ipoib_drain_tx_ring(struct hfi1_ipoib_txq *txq, int budget)
+{
+	struct hfi1_ipoib_circ_buf *tx_ring = &txq->tx_ring;
+	unsigned long head;
+	unsigned long tail;
+	unsigned int max_tx;
+	int work_done;
+	int tx_count;
+
+	spin_lock_bh(&tx_ring->consumer_lock);
+
+	/* Read index before reading contents at that index. */
+	head = smp_load_acquire(&tx_ring->head);
+	tail = tx_ring->tail;
+	max_tx = tx_ring->max_items;
+
+	work_done = min_t(int, CIRC_CNT(head, tail, max_tx), budget);
+
+	for (tx_count = work_done; tx_count; tx_count--) {
+		hfi1_ipoib_free_tx(tx_ring->items[tail], budget);
+		tail = CIRC_NEXT(tail, max_tx);
+	}
+
+	atomic64_add(work_done, &txq->complete_txreqs);
+
+	/* Finished freeing tx items so store the tail value. */
+	smp_store_release(&tx_ring->tail, tail);
+
+	spin_unlock_bh(&tx_ring->consumer_lock);
+
+	hfi1_ipoib_check_queue_stopped(txq);
+
+	return work_done;
+}
+
+static int hfi1_ipoib_process_tx_ring(struct napi_struct *napi, int budget)
+{
+	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(napi->dev);
+	struct hfi1_ipoib_txq *txq = &priv->txqs[napi - priv->tx_napis];
+
+	int work_done = hfi1_ipoib_drain_tx_ring(txq, budget);
+
+	if (work_done < budget)
+		napi_complete_done(napi, work_done);
+
+	return work_done;
+}
+
+static void hfi1_ipoib_add_tx(struct ipoib_txreq *tx)
+{
+	struct hfi1_ipoib_circ_buf *tx_ring = &tx->txq->tx_ring;
+	unsigned long head;
+	unsigned long tail;
+	size_t max_tx;
+
+	spin_lock(&tx_ring->producer_lock);
+
+	head = tx_ring->head;
+	tail = READ_ONCE(tx_ring->tail);
+	max_tx = tx_ring->max_items;
+
+	if (likely(CIRC_SPACE(head, tail, max_tx))) {
+		tx_ring->items[head] = tx;
+
+		/* Finish storing txreq before incrementing head. */
+		smp_store_release(&tx_ring->head, CIRC_ADD(head, 1, max_tx));
+		napi_schedule(tx->txq->napi);
+	} else {
+		struct hfi1_ipoib_txq *txq = tx->txq;
+		struct hfi1_ipoib_dev_priv *priv = tx->priv;
+
+		/* Ring was full */
+		hfi1_ipoib_free_tx(tx, 0);
+		atomic64_inc(&txq->complete_txreqs);
+		dd_dev_dbg(priv->dd, "txq %d full.\n", txq->q_idx);
+	}
+
+	spin_unlock(&tx_ring->producer_lock);
+}
+
+static void hfi1_ipoib_sdma_complete(struct sdma_txreq *txreq, int status)
+{
+	struct ipoib_txreq *tx = container_of(txreq, struct ipoib_txreq, txreq);
+
+	tx->sdma_status = status;
+
+	hfi1_ipoib_add_tx(tx);
+}
+
+static int hfi1_ipoib_build_ulp_payload(struct ipoib_txreq *tx,
+					struct ipoib_txparms *txp)
+{
+	struct hfi1_devdata *dd = txp->dd;
+	struct sdma_txreq *txreq = &tx->txreq;
+	struct sk_buff *skb = tx->skb;
+	int ret = 0;
+	int i;
+
+	if (skb_headlen(skb)) {
+		ret = sdma_txadd_kvaddr(dd, txreq, skb->data, skb_headlen(skb));
+		if (unlikely(ret))
+			return ret;
+	}
+
+	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+		ret = sdma_txadd_page(dd,
+				      txreq,
+				      skb_frag_page(frag),
+				      frag->bv_offset,
+				      skb_frag_size(frag),
+				      NULL, NULL, NULL);
+		if (unlikely(ret))
+			break;
+	}
+
+	return ret;
+}
+
+static int hfi1_ipoib_build_tx_desc(struct ipoib_txreq *tx,
+				    struct ipoib_txparms *txp)
+{
+	struct hfi1_devdata *dd = txp->dd;
+	struct sdma_txreq *txreq = &tx->txreq;
+	struct hfi1_sdma_header *sdma_hdr = &tx->sdma_hdr;
+	u16 pkt_bytes =
+		sizeof(sdma_hdr->pbc) + (txp->hdr_dwords << 2) + tx->skb->len;
+	int ret;
+
+	ret = sdma_txinit(txreq, 0, pkt_bytes, hfi1_ipoib_sdma_complete);
+	if (unlikely(ret))
+		return ret;
+
+	/* add pbc + headers */
+	ret = sdma_txadd_kvaddr(dd,
+				txreq,
+				sdma_hdr,
+				sizeof(sdma_hdr->pbc) + (txp->hdr_dwords << 2));
+	if (unlikely(ret))
+		return ret;
+
+	/* add the ulp payload */
+	return hfi1_ipoib_build_ulp_payload(tx, txp);
+}
+
+static void hfi1_ipoib_build_ib_tx_headers(struct ipoib_txreq *tx,
+					   struct ipoib_txparms *txp)
+{
+	struct hfi1_ipoib_dev_priv *priv = tx->priv;
+	struct hfi1_sdma_header *sdma_hdr = &tx->sdma_hdr;
+	struct sk_buff *skb = tx->skb;
+	struct hfi1_pportdata *ppd = ppd_from_ibp(txp->ibp);
+	struct rdma_ah_attr *ah_attr = txp->ah_attr;
+	struct ib_other_headers *ohdr;
+	struct ib_grh *grh;
+	u16 dwords;
+	u16 slid;
+	u16 dlid;
+	u16 lrh0;
+	u32 bth0;
+	u32 sqpn = (u32)(priv->netdev->dev_addr[1] << 16 |
+			 priv->netdev->dev_addr[2] << 8 |
+			 priv->netdev->dev_addr[3]);
+	u16 payload_dwords;
+	u8 pad_cnt;
+
+	pad_cnt = -skb->len & 3;
+
+	/* Includes ICRC */
+	payload_dwords = ((skb->len + pad_cnt) >> 2) + SIZE_OF_CRC;
+
+	/* header size in dwords LRH+BTH+DETH = (8+12+8)/4. */
+	txp->hdr_dwords = 7;
+
+	if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
+		grh = &sdma_hdr->hdr.ibh.u.l.grh;
+		txp->hdr_dwords +=
+			hfi1_make_grh(txp->ibp,
+				      grh,
+				      rdma_ah_read_grh(ah_attr),
+				      txp->hdr_dwords - LRH_9B_DWORDS,
+				      payload_dwords);
+		lrh0 = HFI1_LRH_GRH;
+		ohdr = &sdma_hdr->hdr.ibh.u.l.oth;
+	} else {
+		lrh0 = HFI1_LRH_BTH;
+		ohdr = &sdma_hdr->hdr.ibh.u.oth;
+	}
+
+	lrh0 |= (rdma_ah_get_sl(ah_attr) & 0xf) << 4;
+	lrh0 |= (txp->flow.sc5 & 0xf) << 12;
+
+	dlid = opa_get_lid(rdma_ah_get_dlid(ah_attr), 9B);
+	if (dlid == be16_to_cpu(IB_LID_PERMISSIVE)) {
+		slid = be16_to_cpu(IB_LID_PERMISSIVE);
+	} else {
+		u16 lid = (u16)ppd->lid;
+
+		if (lid) {
+			lid |= rdma_ah_get_path_bits(ah_attr) &
+				((1 << ppd->lmc) - 1);
+			slid = lid;
+		} else {
+			slid = be16_to_cpu(IB_LID_PERMISSIVE);
+		}
+	}
+
+	/* Includes ICRC */
+	dwords = txp->hdr_dwords + payload_dwords;
+
+	/* Build the lrh */
+	sdma_hdr->hdr.hdr_type = HFI1_PKT_TYPE_9B;
+	hfi1_make_ib_hdr(&sdma_hdr->hdr.ibh, lrh0, dwords, dlid, slid);
+
+	/* Build the bth */
+	bth0 = (IB_OPCODE_UD_SEND_ONLY << 24) | (pad_cnt << 20) | priv->pkey;
+
+	ohdr->bth[0] = cpu_to_be32(bth0);
+	ohdr->bth[1] = cpu_to_be32(txp->dqpn);
+	ohdr->bth[2] = cpu_to_be32(mask_psn((u32)txp->txq->sent_txreqs));
+
+	/* Build the deth */
+	ohdr->u.ud.deth[0] = cpu_to_be32(priv->qkey);
+	ohdr->u.ud.deth[1] = cpu_to_be32((txp->entropy <<
+					  HFI1_IPOIB_ENTROPY_SHIFT) | sqpn);
+
+	/* Construct the pbc. */
+	sdma_hdr->pbc =
+		cpu_to_le64(create_pbc(ppd,
+				       ib_is_sc5(txp->flow.sc5) <<
+							      PBC_DC_INFO_SHIFT,
+				       0,
+				       sc_to_vlt(priv->dd, txp->flow.sc5),
+				       dwords - SIZE_OF_CRC +
+						(sizeof(sdma_hdr->pbc) >> 2)));
+}
+
+static struct ipoib_txreq *hfi1_ipoib_send_dma_common(struct net_device *dev,
+						      struct sk_buff *skb,
+						      struct ipoib_txparms *txp)
+{
+	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
+	struct ipoib_txreq *tx;
+	int ret;
+
+	tx = kmem_cache_alloc_node(priv->txreq_cache,
+				   GFP_ATOMIC,
+				   priv->dd->node);
+	if (unlikely(!tx))
+		return ERR_PTR(-ENOMEM);
+
+	/* so that we can test if the sdma descriptors are there */
+	tx->txreq.num_desc = 0;
+	tx->priv = priv;
+	tx->txq = txp->txq;
+	tx->skb = skb;
+	INIT_LIST_HEAD(&tx->txreq.list);
+
+	hfi1_ipoib_build_ib_tx_headers(tx, txp);
+
+	ret = hfi1_ipoib_build_tx_desc(tx, txp);
+	if (likely(!ret)) {
+		if (txp->txq->flow.as_int != txp->flow.as_int) {
+			txp->txq->flow.tx_queue = txp->flow.tx_queue;
+			txp->txq->flow.sc5 = txp->flow.sc5;
+			txp->txq->sde =
+				sdma_select_engine_sc(priv->dd,
+						      txp->flow.tx_queue,
+						      txp->flow.sc5);
+			trace_hfi1_flow_switch(txp->txq);
+		}
+
+		return tx;
+	}
+
+	sdma_txclean(priv->dd, &tx->txreq);
+	kmem_cache_free(priv->txreq_cache, tx);
+
+	return ERR_PTR(ret);
+}
+
+static int hfi1_ipoib_submit_tx_list(struct net_device *dev,
+				     struct hfi1_ipoib_txq *txq)
+{
+	int ret;
+	u16 count_out;
+
+	ret = sdma_send_txlist(txq->sde,
+			       iowait_get_ib_work(&txq->wait),
+			       &txq->tx_list,
+			       &count_out);
+	if (likely(!ret) || ret == -EBUSY || ret == -ECOMM)
+		return ret;
+
+	dd_dev_warn(txq->priv->dd, "cannot send skb tx list, err %d.\n", ret);
+
+	return ret;
+}
+
+static int hfi1_ipoib_flush_tx_list(struct net_device *dev,
+				    struct hfi1_ipoib_txq *txq)
+{
+	int ret = 0;
+
+	if (!list_empty(&txq->tx_list)) {
+		/* Flush the current list */
+		ret = hfi1_ipoib_submit_tx_list(dev, txq);
+
+		if (unlikely(ret))
+			if (ret != -EBUSY)
+				++dev->stats.tx_carrier_errors;
+	}
+
+	return ret;
+}
+
+static int hfi1_ipoib_submit_tx(struct hfi1_ipoib_txq *txq,
+				struct ipoib_txreq *tx)
+{
+	int ret;
+
+	ret = sdma_send_txreq(txq->sde,
+			      iowait_get_ib_work(&txq->wait),
+			      &tx->txreq,
+			      txq->pkts_sent);
+	if (likely(!ret)) {
+		txq->pkts_sent = true;
+		iowait_starve_clear(txq->pkts_sent, &txq->wait);
+	}
+
+	return ret;
+}
+
+static int hfi1_ipoib_send_dma_single(struct net_device *dev,
+				      struct sk_buff *skb,
+				      struct ipoib_txparms *txp)
+{
+	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
+	struct hfi1_ipoib_txq *txq = txp->txq;
+	struct ipoib_txreq *tx;
+	int ret;
+
+	tx = hfi1_ipoib_send_dma_common(dev, skb, txp);
+	if (IS_ERR(tx)) {
+		int ret = PTR_ERR(tx);
+
+		dev_kfree_skb_any(skb);
+
+		if (ret == -ENOMEM)
+			++dev->stats.tx_errors;
+		else
+			++dev->stats.tx_carrier_errors;
+
+		return NETDEV_TX_OK;
+	}
+
+	ret = hfi1_ipoib_submit_tx(txq, tx);
+	if (likely(!ret)) {
+tx_ok:
+		trace_sdma_output_ibhdr(tx->priv->dd,
+					&tx->sdma_hdr.hdr,
+					ib_is_sc5(txp->flow.sc5));
+		hfi1_ipoib_check_queue_depth(txq);
+		return NETDEV_TX_OK;
+	}
+
+	txq->pkts_sent = false;
+
+	if (ret == -EBUSY || ret == -ECOMM)
+		goto tx_ok;
+
+	sdma_txclean(priv->dd, &tx->txreq);
+	dev_kfree_skb_any(skb);
+	kmem_cache_free(priv->txreq_cache, tx);
+	++dev->stats.tx_carrier_errors;
+
+	return NETDEV_TX_OK;
+}
+
+static int hfi1_ipoib_send_dma_list(struct net_device *dev,
+				    struct sk_buff *skb,
+				    struct ipoib_txparms *txp)
+{
+	struct hfi1_ipoib_txq *txq = txp->txq;
+	struct ipoib_txreq *tx;
+
+	/* Has the flow change ? */
+	if (txq->flow.as_int != txp->flow.as_int) {
+		int ret;
+
+		trace_hfi1_flow_flush(txq);
+		ret = hfi1_ipoib_flush_tx_list(dev, txq);
+		if (unlikely(ret)) {
+			if (ret == -EBUSY)
+				++dev->stats.tx_dropped;
+			dev_kfree_skb_any(skb);
+			return NETDEV_TX_OK;
+		}
+	}
+	tx = hfi1_ipoib_send_dma_common(dev, skb, txp);
+	if (IS_ERR(tx)) {
+		int ret = PTR_ERR(tx);
+
+		dev_kfree_skb_any(skb);
+
+		if (ret == -ENOMEM)
+			++dev->stats.tx_errors;
+		else
+			++dev->stats.tx_carrier_errors;
+
+		return NETDEV_TX_OK;
+	}
+
+	list_add_tail(&tx->txreq.list, &txq->tx_list);
+
+	hfi1_ipoib_check_queue_depth(txq);
+
+	trace_sdma_output_ibhdr(tx->priv->dd,
+				&tx->sdma_hdr.hdr,
+				ib_is_sc5(txp->flow.sc5));
+
+	if (!netdev_xmit_more())
+		(void)hfi1_ipoib_flush_tx_list(dev, txq);
+
+	return NETDEV_TX_OK;
+}
+
+static u8 hfi1_ipoib_calc_entropy(struct sk_buff *skb)
+{
+	if (skb_transport_header_was_set(skb)) {
+		u8 *hdr = (u8 *)skb_transport_header(skb);
+
+		return (hdr[0] ^ hdr[1] ^ hdr[2] ^ hdr[3]);
+	}
+
+	return (u8)skb_get_queue_mapping(skb);
+}
+
+int hfi1_ipoib_send_dma(struct net_device *dev,
+			struct sk_buff *skb,
+			struct ib_ah *address,
+			u32 dqpn)
+{
+	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
+	struct ipoib_txparms txp;
+	struct rdma_netdev *rn = netdev_priv(dev);
+
+	if (unlikely(skb->len > rn->mtu + HFI1_IPOIB_ENCAP_LEN)) {
+		dd_dev_warn(priv->dd, "packet len %d (> %d) too long to send, dropping\n",
+			    skb->len,
+			    rn->mtu + HFI1_IPOIB_ENCAP_LEN);
+		++dev->stats.tx_dropped;
+		++dev->stats.tx_errors;
+		dev_kfree_skb_any(skb);
+		return NETDEV_TX_OK;
+	}
+
+	txp.dd = priv->dd;
+	txp.ah_attr = &ibah_to_rvtah(address)->attr;
+	txp.ibp = to_iport(priv->device, priv->port_num);
+	txp.txq = &priv->txqs[skb_get_queue_mapping(skb)];
+	txp.dqpn = dqpn;
+	txp.flow.sc5 = txp.ibp->sl_to_sc[rdma_ah_get_sl(txp.ah_attr)];
+	txp.flow.tx_queue = (u8)skb_get_queue_mapping(skb);
+	txp.entropy = hfi1_ipoib_calc_entropy(skb);
+
+	if (netdev_xmit_more() || !list_empty(&txp.txq->tx_list))
+		return hfi1_ipoib_send_dma_list(dev, skb, &txp);
+
+	return hfi1_ipoib_send_dma_single(dev, skb,  &txp);
+}
+
+/*
+ * hfi1_ipoib_sdma_sleep - ipoib sdma sleep function
+ *
+ * This function gets called from sdma_send_txreq() when there are not enough
+ * sdma descriptors available to send the packet. It adds Tx queue's wait
+ * structure to sdma engine's dmawait list to be woken up when descriptors
+ * become available.
+ */
+static int hfi1_ipoib_sdma_sleep(struct sdma_engine *sde,
+				 struct iowait_work *wait,
+				 struct sdma_txreq *txreq,
+				 uint seq,
+				 bool pkts_sent)
+{
+	struct hfi1_ipoib_txq *txq =
+		container_of(wait->iow, struct hfi1_ipoib_txq, wait);
+
+	write_seqlock(&sde->waitlock);
+
+	if (likely(txq->priv->netdev->reg_state == NETREG_REGISTERED)) {
+		if (sdma_progress(sde, seq, txreq)) {
+			write_sequnlock(&sde->waitlock);
+			return -EAGAIN;
+		}
+
+		if (list_empty(&txreq->list))
+			/* came from non-list submit */
+			list_add_tail(&txreq->list, &txq->tx_list);
+		if (list_empty(&txq->wait.list)) {
+			if (!atomic_xchg(&txq->no_desc, 1)) {
+				trace_hfi1_txq_queued(txq);
+				hfi1_ipoib_stop_txq(txq);
+			}
+			iowait_queue(pkts_sent, wait->iow, &sde->dmawait);
+		}
+
+		write_sequnlock(&sde->waitlock);
+		return -EBUSY;
+	}
+
+	write_sequnlock(&sde->waitlock);
+	return -EINVAL;
+}
+
+/*
+ * hfi1_ipoib_sdma_wakeup - ipoib sdma wakeup function
+ *
+ * This function gets called when SDMA descriptors becomes available and Tx
+ * queue's wait structure was previously added to sdma engine's dmawait list.
+ */
+static void hfi1_ipoib_sdma_wakeup(struct iowait *wait, int reason)
+{
+	struct hfi1_ipoib_txq *txq =
+		container_of(wait, struct hfi1_ipoib_txq, wait);
+
+	trace_hfi1_txq_wakeup(txq);
+	if (likely(txq->priv->netdev->reg_state == NETREG_REGISTERED))
+		iowait_schedule(wait, system_highpri_wq, WORK_CPU_UNBOUND);
+}
+
+static void hfi1_ipoib_flush_txq(struct work_struct *work)
+{
+	struct iowait_work *ioww =
+		container_of(work, struct iowait_work, iowork);
+	struct iowait *wait = iowait_ioww_to_iow(ioww);
+	struct hfi1_ipoib_txq *txq =
+		container_of(wait, struct hfi1_ipoib_txq, wait);
+	struct net_device *dev = txq->priv->netdev;
+
+	if (likely(dev->reg_state == NETREG_REGISTERED) &&
+	    likely(!hfi1_ipoib_flush_tx_list(dev, txq)))
+		if (atomic_xchg(&txq->no_desc, 0))
+			hfi1_ipoib_wake_txq(txq);
+}
+
+int hfi1_ipoib_txreq_init(struct hfi1_ipoib_dev_priv *priv)
+{
+	struct net_device *dev = priv->netdev;
+	char buf[HFI1_IPOIB_TXREQ_NAME_LEN];
+	unsigned long tx_ring_size;
+	int i;
+
+	/*
+	 * Ring holds 1 less than tx_ring_size
+	 * Round up to next power of 2 in order to hold at least tx_queue_len
+	 */
+	tx_ring_size = roundup_pow_of_two((unsigned long)dev->tx_queue_len + 1);
+
+	snprintf(buf, sizeof(buf), "hfi1_%u_ipoib_txreq_cache", priv->dd->unit);
+	priv->txreq_cache = kmem_cache_create(buf,
+					      sizeof(struct ipoib_txreq),
+					      0,
+					      0,
+					      NULL);
+	if (!priv->txreq_cache)
+		return -ENOMEM;
+
+	priv->tx_napis = kcalloc_node(dev->num_tx_queues,
+				      sizeof(struct napi_struct),
+				      GFP_KERNEL,
+				      priv->dd->node);
+	if (!priv->tx_napis)
+		goto free_txreq_cache;
+
+	priv->txqs = kcalloc_node(dev->num_tx_queues,
+				  sizeof(struct hfi1_ipoib_txq),
+				  GFP_KERNEL,
+				  priv->dd->node);
+	if (!priv->txqs)
+		goto free_tx_napis;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
+
+		iowait_init(&txq->wait,
+			    0,
+			    hfi1_ipoib_flush_txq,
+			    NULL,
+			    hfi1_ipoib_sdma_sleep,
+			    hfi1_ipoib_sdma_wakeup,
+			    NULL,
+			    NULL);
+		txq->priv = priv;
+		txq->sde = NULL;
+		INIT_LIST_HEAD(&txq->tx_list);
+		atomic64_set(&txq->complete_txreqs, 0);
+		atomic_set(&txq->stops, 0);
+		atomic_set(&txq->ring_full, 0);
+		atomic_set(&txq->no_desc, 0);
+		txq->q_idx = i;
+		txq->flow.tx_queue = 0xff;
+		txq->flow.sc5 = 0xff;
+		txq->pkts_sent = false;
+
+		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
+					     priv->dd->node);
+
+		txq->tx_ring.items =
+			kcalloc_node(tx_ring_size,
+				     sizeof(struct ipoib_txreq *),
+				     GFP_KERNEL, priv->dd->node);
+		if (!txq->tx_ring.items)
+			goto free_txqs;
+
+		spin_lock_init(&txq->tx_ring.producer_lock);
+		spin_lock_init(&txq->tx_ring.consumer_lock);
+		txq->tx_ring.max_items = tx_ring_size;
+
+		txq->napi = &priv->tx_napis[i];
+		netif_tx_napi_add(dev, txq->napi,
+				  hfi1_ipoib_process_tx_ring,
+				  NAPI_POLL_WEIGHT);
+	}
+
+	return 0;
+
+free_txqs:
+	for (i--; i >= 0; i--) {
+		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
+
+		netif_napi_del(txq->napi);
+		kfree(txq->tx_ring.items);
+	}
+
+	kfree(priv->txqs);
+	priv->txqs = NULL;
+
+free_tx_napis:
+	kfree(priv->tx_napis);
+	priv->tx_napis = NULL;
+
+free_txreq_cache:
+	kmem_cache_destroy(priv->txreq_cache);
+	priv->txreq_cache = NULL;
+	return -ENOMEM;
+}
+
+static void hfi1_ipoib_drain_tx_list(struct hfi1_ipoib_txq *txq)
+{
+	struct sdma_txreq *txreq;
+	struct sdma_txreq *txreq_tmp;
+	atomic64_t *complete_txreqs = &txq->complete_txreqs;
+
+	list_for_each_entry_safe(txreq, txreq_tmp, &txq->tx_list, list) {
+		struct ipoib_txreq *tx =
+			container_of(txreq, struct ipoib_txreq, txreq);
+
+		list_del(&txreq->list);
+		sdma_txclean(txq->priv->dd, &tx->txreq);
+		dev_kfree_skb_any(tx->skb);
+		kmem_cache_free(txq->priv->txreq_cache, tx);
+		atomic64_inc(complete_txreqs);
+	}
+
+	if (hfi1_ipoib_used(txq))
+		dd_dev_warn(txq->priv->dd,
+			    "txq %d not empty found %llu requests\n",
+			    txq->q_idx,
+			    hfi1_ipoib_txreqs(txq->sent_txreqs,
+					      atomic64_read(complete_txreqs)));
+}
+
+void hfi1_ipoib_txreq_deinit(struct hfi1_ipoib_dev_priv *priv)
+{
+	int i;
+
+	for (i = 0; i < priv->netdev->num_tx_queues; i++) {
+		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
+
+		iowait_cancel_work(&txq->wait);
+		iowait_sdma_drain(&txq->wait);
+		hfi1_ipoib_drain_tx_list(txq);
+		netif_napi_del(txq->napi);
+		(void)hfi1_ipoib_drain_tx_ring(txq, txq->tx_ring.max_items);
+		kfree(txq->tx_ring.items);
+	}
+
+	kfree(priv->txqs);
+	priv->txqs = NULL;
+
+	kfree(priv->tx_napis);
+	priv->tx_napis = NULL;
+
+	kmem_cache_destroy(priv->txreq_cache);
+	priv->txreq_cache = NULL;
+}
+
+void hfi1_ipoib_napi_tx_enable(struct net_device *dev)
+{
+	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
+	int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
+
+		napi_enable(txq->napi);
+	}
+}
+
+void hfi1_ipoib_napi_tx_disable(struct net_device *dev)
+{
+	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(dev);
+	int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
+
+		napi_disable(txq->napi);
+		(void)hfi1_ipoib_drain_tx_ring(txq, txq->tx_ring.max_items);
+	}
+}