Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:
 "Some highlights from this development cycle:

   1) Big refactoring of ipv6 route and neigh handling to support
      nexthop objects configurable as units from userspace. From David
      Ahern.

   2) Convert explored_states in BPF verifier into a hash table,
      significantly decreased state held for programs with bpf2bpf
      calls, from Alexei Starovoitov.

   3) Implement bpf_send_signal() helper, from Yonghong Song.

   4) Various classifier enhancements to mvpp2 driver, from Maxime
      Chevallier.

   5) Add aRFS support to hns3 driver, from Jian Shen.

   6) Fix use after free in inet frags by allocating fqdirs dynamically
      and reworking how rhashtable dismantle occurs, from Eric Dumazet.

   7) Add act_ctinfo packet classifier action, from Kevin
      Darbyshire-Bryant.

   8) Add TFO key backup infrastructure, from Jason Baron.

   9) Remove several old and unused ISDN drivers, from Arnd Bergmann.

  10) Add devlink notifications for flash update status to mlxsw driver,
      from Jiri Pirko.

  11) Lots of kTLS offload infrastructure fixes, from Jakub Kicinski.

  12) Add support for mv88e6250 DSA chips, from Rasmus Villemoes.

  13) Various enhancements to ipv6 flow label handling, from Eric
      Dumazet and Willem de Bruijn.

  14) Support TLS offload in nfp driver, from Jakub Kicinski, Dirk van
      der Merwe, and others.

  15) Various improvements to axienet driver including converting it to
      phylink, from Robert Hancock.

  16) Add PTP support to sja1105 DSA driver, from Vladimir Oltean.

  17) Add mqprio qdisc offload support to dpaa2-eth, from Ioana
      Radulescu.

  18) Add devlink health reporting to mlx5, from Moshe Shemesh.

  19) Convert stmmac over to phylink, from Jose Abreu.

  20) Add PTP PHC (Physical Hardware Clock) support to mlxsw, from
      Shalom Toledo.

  21) Add nftables SYNPROXY support, from Fernando Fernandez Mancera.

  22) Convert tcp_fastopen over to use SipHash, from Ard Biesheuvel.

  23) Track spill/fill of constants in BPF verifier, from Alexei
      Starovoitov.

  24) Support bounded loops in BPF, from Alexei Starovoitov.

  25) Various page_pool API fixes and improvements, from Jesper Dangaard
      Brouer.

  26) Just like ipv4, support ref-countless ipv6 route handling. From
      Wei Wang.

  27) Support VLAN offloading in aquantia driver, from Igor Russkikh.

  28) Add AF_XDP zero-copy support to mlx5, from Maxim Mikityanskiy.

  29) Add flower GRE encap/decap support to nfp driver, from Pieter
      Jansen van Vuuren.

  30) Protect against stack overflow when using act_mirred, from John
      Hurley.

  31) Allow devmap map lookups from eBPF, from Toke Høiland-Jørgensen.

  32) Use page_pool API in netsec driver, Ilias Apalodimas.

  33) Add Google gve network driver, from Catherine Sullivan.

  34) More indirect call avoidance, from Paolo Abeni.

  35) Add kTLS TX HW offload support to mlx5, from Tariq Toukan.

  36) Add XDP_REDIRECT support to bnxt_en, from Andy Gospodarek.

  37) Add MPLS manipulation actions to TC, from John Hurley.

  38) Add sending a packet to connection tracking from TC actions, and
      then allow flower classifier matching on conntrack state. From
      Paul Blakey.

  39) Netfilter hw offload support, from Pablo Neira Ayuso"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2080 commits)
  net/mlx5e: Return in default case statement in tx_post_resync_params
  mlx5: Return -EINVAL when WARN_ON_ONCE triggers in mlx5e_tls_resync().
  net: dsa: add support for BRIDGE_MROUTER attribute
  pkt_sched: Include const.h
  net: netsec: remove static declaration for netsec_set_tx_de()
  net: netsec: remove superfluous if statement
  netfilter: nf_tables: add hardware offload support
  net: flow_offload: rename tc_cls_flower_offload to flow_cls_offload
  net: flow_offload: add flow_block_cb_is_busy() and use it
  net: sched: remove tcf block API
  drivers: net: use flow block API
  net: sched: use flow block API
  net: flow_offload: add flow_block_cb_{priv, incref, decref}()
  net: flow_offload: add list handling functions
  net: flow_offload: add flow_block_cb_alloc() and flow_block_cb_free()
  net: flow_offload: rename TCF_BLOCK_BINDER_TYPE_* to FLOW_BLOCK_BINDER_TYPE_*
  net: flow_offload: rename TC_BLOCK_{UN}BIND to FLOW_BLOCK_{UN}BIND
  net: flow_offload: add flow_block_cb_setup_simple()
  net: hisilicon: Add an tx_desc to adapt HI13X1_GMAC
  net: hisilicon: Add an rx_desc to adapt HI13X1_GMAC
  ...

1 files changed, 584 insertions, 0 deletions

diff --git a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c
new file mode 100644
index 000000000000..778b87b5a06c
--- /dev/null
+++ b/drivers/net/ethernet/google/gve/gve_tx.c
@@ -0,0 +1,584 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/* Google virtual Ethernet (gve) driver
+ *
+ * Copyright (C) 2015-2019 Google, Inc.
+ */
+
+#include "gve.h"
+#include "gve_adminq.h"
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/vmalloc.h>
+#include <linux/skbuff.h>
+
+static inline void gve_tx_put_doorbell(struct gve_priv *priv,
+				       struct gve_queue_resources *q_resources,
+				       u32 val)
+{
+	iowrite32be(val, &priv->db_bar2[be32_to_cpu(q_resources->db_index)]);
+}
+
+/* gvnic can only transmit from a Registered Segment.
+ * We copy skb payloads into the registered segment before writing Tx
+ * descriptors and ringing the Tx doorbell.
+ *
+ * gve_tx_fifo_* manages the Registered Segment as a FIFO - clients must
+ * free allocations in the order they were allocated.
+ */
+
+static int gve_tx_fifo_init(struct gve_priv *priv, struct gve_tx_fifo *fifo)
+{
+	fifo->base = vmap(fifo->qpl->pages, fifo->qpl->num_entries, VM_MAP,
+			  PAGE_KERNEL);
+	if (unlikely(!fifo->base)) {
+		netif_err(priv, drv, priv->dev, "Failed to vmap fifo, qpl_id = %d\n",
+			  fifo->qpl->id);
+		return -ENOMEM;
+	}
+
+	fifo->size = fifo->qpl->num_entries * PAGE_SIZE;
+	atomic_set(&fifo->available, fifo->size);
+	fifo->head = 0;
+	return 0;
+}
+
+static void gve_tx_fifo_release(struct gve_priv *priv, struct gve_tx_fifo *fifo)
+{
+	WARN(atomic_read(&fifo->available) != fifo->size,
+	     "Releasing non-empty fifo");
+
+	vunmap(fifo->base);
+}
+
+static int gve_tx_fifo_pad_alloc_one_frag(struct gve_tx_fifo *fifo,
+					  size_t bytes)
+{
+	return (fifo->head + bytes < fifo->size) ? 0 : fifo->size - fifo->head;
+}
+
+static bool gve_tx_fifo_can_alloc(struct gve_tx_fifo *fifo, size_t bytes)
+{
+	return (atomic_read(&fifo->available) <= bytes) ? false : true;
+}
+
+/* gve_tx_alloc_fifo - Allocate fragment(s) from Tx FIFO
+ * @fifo: FIFO to allocate from
+ * @bytes: Allocation size
+ * @iov: Scatter-gather elements to fill with allocation fragment base/len
+ *
+ * Returns number of valid elements in iov[] or negative on error.
+ *
+ * Allocations from a given FIFO must be externally synchronized but concurrent
+ * allocation and frees are allowed.
+ */
+static int gve_tx_alloc_fifo(struct gve_tx_fifo *fifo, size_t bytes,
+			     struct gve_tx_iovec iov[2])
+{
+	size_t overflow, padding;
+	u32 aligned_head;
+	int nfrags = 0;
+
+	if (!bytes)
+		return 0;
+
+	/* This check happens before we know how much padding is needed to
+	 * align to a cacheline boundary for the payload, but that is fine,
+	 * because the FIFO head always start aligned, and the FIFO's boundaries
+	 * are aligned, so if there is space for the data, there is space for
+	 * the padding to the next alignment.
+	 */
+	WARN(!gve_tx_fifo_can_alloc(fifo, bytes),
+	     "Reached %s when there's not enough space in the fifo", __func__);
+
+	nfrags++;
+
+	iov[0].iov_offset = fifo->head;
+	iov[0].iov_len = bytes;
+	fifo->head += bytes;
+
+	if (fifo->head > fifo->size) {
+		/* If the allocation did not fit in the tail fragment of the
+		 * FIFO, also use the head fragment.
+		 */
+		nfrags++;
+		overflow = fifo->head - fifo->size;
+		iov[0].iov_len -= overflow;
+		iov[1].iov_offset = 0;	/* Start of fifo*/
+		iov[1].iov_len = overflow;
+
+		fifo->head = overflow;
+	}
+
+	/* Re-align to a cacheline boundary */
+	aligned_head = L1_CACHE_ALIGN(fifo->head);
+	padding = aligned_head - fifo->head;
+	iov[nfrags - 1].iov_padding = padding;
+	atomic_sub(bytes + padding, &fifo->available);
+	fifo->head = aligned_head;
+
+	if (fifo->head == fifo->size)
+		fifo->head = 0;
+
+	return nfrags;
+}
+
+/* gve_tx_free_fifo - Return space to Tx FIFO
+ * @fifo: FIFO to return fragments to
+ * @bytes: Bytes to free
+ */
+static void gve_tx_free_fifo(struct gve_tx_fifo *fifo, size_t bytes)
+{
+	atomic_add(bytes, &fifo->available);
+}
+
+static void gve_tx_remove_from_block(struct gve_priv *priv, int queue_idx)
+{
+	struct gve_notify_block *block =
+			&priv->ntfy_blocks[gve_tx_idx_to_ntfy(priv, queue_idx)];
+
+	block->tx = NULL;
+}
+
+static int gve_clean_tx_done(struct gve_priv *priv, struct gve_tx_ring *tx,
+			     u32 to_do, bool try_to_wake);
+
+static void gve_tx_free_ring(struct gve_priv *priv, int idx)
+{
+	struct gve_tx_ring *tx = &priv->tx[idx];
+	struct device *hdev = &priv->pdev->dev;
+	size_t bytes;
+	u32 slots;
+
+	gve_tx_remove_from_block(priv, idx);
+	slots = tx->mask + 1;
+	gve_clean_tx_done(priv, tx, tx->req, false);
+	netdev_tx_reset_queue(tx->netdev_txq);
+
+	dma_free_coherent(hdev, sizeof(*tx->q_resources),
+			  tx->q_resources, tx->q_resources_bus);
+	tx->q_resources = NULL;
+
+	gve_tx_fifo_release(priv, &tx->tx_fifo);
+	gve_unassign_qpl(priv, tx->tx_fifo.qpl->id);
+	tx->tx_fifo.qpl = NULL;
+
+	bytes = sizeof(*tx->desc) * slots;
+	dma_free_coherent(hdev, bytes, tx->desc, tx->bus);
+	tx->desc = NULL;
+
+	vfree(tx->info);
+	tx->info = NULL;
+
+	netif_dbg(priv, drv, priv->dev, "freed tx queue %d\n", idx);
+}
+
+static void gve_tx_add_to_block(struct gve_priv *priv, int queue_idx)
+{
+	int ntfy_idx = gve_tx_idx_to_ntfy(priv, queue_idx);
+	struct gve_notify_block *block = &priv->ntfy_blocks[ntfy_idx];
+	struct gve_tx_ring *tx = &priv->tx[queue_idx];
+
+	block->tx = tx;
+	tx->ntfy_id = ntfy_idx;
+}
+
+static int gve_tx_alloc_ring(struct gve_priv *priv, int idx)
+{
+	struct gve_tx_ring *tx = &priv->tx[idx];
+	struct device *hdev = &priv->pdev->dev;
+	u32 slots = priv->tx_desc_cnt;
+	size_t bytes;
+
+	/* Make sure everything is zeroed to start */
+	memset(tx, 0, sizeof(*tx));
+	tx->q_num = idx;
+
+	tx->mask = slots - 1;
+
+	/* alloc metadata */
+	tx->info = vzalloc(sizeof(*tx->info) * slots);
+	if (!tx->info)
+		return -ENOMEM;
+
+	/* alloc tx queue */
+	bytes = sizeof(*tx->desc) * slots;
+	tx->desc = dma_alloc_coherent(hdev, bytes, &tx->bus, GFP_KERNEL);
+	if (!tx->desc)
+		goto abort_with_info;
+
+	tx->tx_fifo.qpl = gve_assign_tx_qpl(priv);
+
+	/* map Tx FIFO */
+	if (gve_tx_fifo_init(priv, &tx->tx_fifo))
+		goto abort_with_desc;
+
+	tx->q_resources =
+		dma_alloc_coherent(hdev,
+				   sizeof(*tx->q_resources),
+				   &tx->q_resources_bus,
+				   GFP_KERNEL);
+	if (!tx->q_resources)
+		goto abort_with_fifo;
+
+	netif_dbg(priv, drv, priv->dev, "tx[%d]->bus=%lx\n", idx,
+		  (unsigned long)tx->bus);
+	tx->netdev_txq = netdev_get_tx_queue(priv->dev, idx);
+	gve_tx_add_to_block(priv, idx);
+
+	return 0;
+
+abort_with_fifo:
+	gve_tx_fifo_release(priv, &tx->tx_fifo);
+abort_with_desc:
+	dma_free_coherent(hdev, bytes, tx->desc, tx->bus);
+	tx->desc = NULL;
+abort_with_info:
+	vfree(tx->info);
+	tx->info = NULL;
+	return -ENOMEM;
+}
+
+int gve_tx_alloc_rings(struct gve_priv *priv)
+{
+	int err = 0;
+	int i;
+
+	for (i = 0; i < priv->tx_cfg.num_queues; i++) {
+		err = gve_tx_alloc_ring(priv, i);
+		if (err) {
+			netif_err(priv, drv, priv->dev,
+				  "Failed to alloc tx ring=%d: err=%d\n",
+				  i, err);
+			break;
+		}
+	}
+	/* Unallocate if there was an error */
+	if (err) {
+		int j;
+
+		for (j = 0; j < i; j++)
+			gve_tx_free_ring(priv, j);
+	}
+	return err;
+}
+
+void gve_tx_free_rings(struct gve_priv *priv)
+{
+	int i;
+
+	for (i = 0; i < priv->tx_cfg.num_queues; i++)
+		gve_tx_free_ring(priv, i);
+}
+
+/* gve_tx_avail - Calculates the number of slots available in the ring
+ * @tx: tx ring to check
+ *
+ * Returns the number of slots available
+ *
+ * The capacity of the queue is mask + 1. We don't need to reserve an entry.
+ **/
+static inline u32 gve_tx_avail(struct gve_tx_ring *tx)
+{
+	return tx->mask + 1 - (tx->req - tx->done);
+}
+
+static inline int gve_skb_fifo_bytes_required(struct gve_tx_ring *tx,
+					      struct sk_buff *skb)
+{
+	int pad_bytes, align_hdr_pad;
+	int bytes;
+	int hlen;
+
+	hlen = skb_is_gso(skb) ? skb_checksum_start_offset(skb) +
+				 tcp_hdrlen(skb) : skb_headlen(skb);
+
+	pad_bytes = gve_tx_fifo_pad_alloc_one_frag(&tx->tx_fifo,
+						   hlen);
+	/* We need to take into account the header alignment padding. */
+	align_hdr_pad = L1_CACHE_ALIGN(hlen) - hlen;
+	bytes = align_hdr_pad + pad_bytes + skb->len;
+
+	return bytes;
+}
+
+/* The most descriptors we could need are 3 - 1 for the headers, 1 for
+ * the beginning of the payload at the end of the FIFO, and 1 if the
+ * payload wraps to the beginning of the FIFO.
+ */
+#define MAX_TX_DESC_NEEDED	3
+
+/* Check if sufficient resources (descriptor ring space, FIFO space) are
+ * available to transmit the given number of bytes.
+ */
+static inline bool gve_can_tx(struct gve_tx_ring *tx, int bytes_required)
+{
+	return (gve_tx_avail(tx) >= MAX_TX_DESC_NEEDED &&
+		gve_tx_fifo_can_alloc(&tx->tx_fifo, bytes_required));
+}
+
+/* Stops the queue if the skb cannot be transmitted. */
+static int gve_maybe_stop_tx(struct gve_tx_ring *tx, struct sk_buff *skb)
+{
+	int bytes_required;
+
+	bytes_required = gve_skb_fifo_bytes_required(tx, skb);
+	if (likely(gve_can_tx(tx, bytes_required)))
+		return 0;
+
+	/* No space, so stop the queue */
+	tx->stop_queue++;
+	netif_tx_stop_queue(tx->netdev_txq);
+	smp_mb();	/* sync with restarting queue in gve_clean_tx_done() */
+
+	/* Now check for resources again, in case gve_clean_tx_done() freed
+	 * resources after we checked and we stopped the queue after
+	 * gve_clean_tx_done() checked.
+	 *
+	 * gve_maybe_stop_tx()			gve_clean_tx_done()
+	 *   nsegs/can_alloc test failed
+	 *					  gve_tx_free_fifo()
+	 *					  if (tx queue stopped)
+	 *					    netif_tx_queue_wake()
+	 *   netif_tx_stop_queue()
+	 *   Need to check again for space here!
+	 */
+	if (likely(!gve_can_tx(tx, bytes_required)))
+		return -EBUSY;
+
+	netif_tx_start_queue(tx->netdev_txq);
+	tx->wake_queue++;
+	return 0;
+}
+
+static void gve_tx_fill_pkt_desc(union gve_tx_desc *pkt_desc,
+				 struct sk_buff *skb, bool is_gso,
+				 int l4_hdr_offset, u32 desc_cnt,
+				 u16 hlen, u64 addr)
+{
+	/* l4_hdr_offset and csum_offset are in units of 16-bit words */
+	if (is_gso) {
+		pkt_desc->pkt.type_flags = GVE_TXD_TSO | GVE_TXF_L4CSUM;
+		pkt_desc->pkt.l4_csum_offset = skb->csum_offset >> 1;
+		pkt_desc->pkt.l4_hdr_offset = l4_hdr_offset >> 1;
+	} else if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
+		pkt_desc->pkt.type_flags = GVE_TXD_STD | GVE_TXF_L4CSUM;
+		pkt_desc->pkt.l4_csum_offset = skb->csum_offset >> 1;
+		pkt_desc->pkt.l4_hdr_offset = l4_hdr_offset >> 1;
+	} else {
+		pkt_desc->pkt.type_flags = GVE_TXD_STD;
+		pkt_desc->pkt.l4_csum_offset = 0;
+		pkt_desc->pkt.l4_hdr_offset = 0;
+	}
+	pkt_desc->pkt.desc_cnt = desc_cnt;
+	pkt_desc->pkt.len = cpu_to_be16(skb->len);
+	pkt_desc->pkt.seg_len = cpu_to_be16(hlen);
+	pkt_desc->pkt.seg_addr = cpu_to_be64(addr);
+}
+
+static void gve_tx_fill_seg_desc(union gve_tx_desc *seg_desc,
+				 struct sk_buff *skb, bool is_gso,
+				 u16 len, u64 addr)
+{
+	seg_desc->seg.type_flags = GVE_TXD_SEG;
+	if (is_gso) {
+		if (skb_is_gso_v6(skb))
+			seg_desc->seg.type_flags |= GVE_TXSF_IPV6;
+		seg_desc->seg.l3_offset = skb_network_offset(skb) >> 1;
+		seg_desc->seg.mss = cpu_to_be16(skb_shinfo(skb)->gso_size);
+	}
+	seg_desc->seg.seg_len = cpu_to_be16(len);
+	seg_desc->seg.seg_addr = cpu_to_be64(addr);
+}
+
+static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb)
+{
+	int pad_bytes, hlen, hdr_nfrags, payload_nfrags, l4_hdr_offset;
+	union gve_tx_desc *pkt_desc, *seg_desc;
+	struct gve_tx_buffer_state *info;
+	bool is_gso = skb_is_gso(skb);
+	u32 idx = tx->req & tx->mask;
+	int payload_iov = 2;
+	int copy_offset;
+	u32 next_idx;
+	int i;
+
+	info = &tx->info[idx];
+	pkt_desc = &tx->desc[idx];
+
+	l4_hdr_offset = skb_checksum_start_offset(skb);
+	/* If the skb is gso, then we want the tcp header in the first segment
+	 * otherwise we want the linear portion of the skb (which will contain
+	 * the checksum because skb->csum_start and skb->csum_offset are given
+	 * relative to skb->head) in the first segment.
+	 */
+	hlen = is_gso ? l4_hdr_offset + tcp_hdrlen(skb) :
+			skb_headlen(skb);
+
+	info->skb =  skb;
+	/* We don't want to split the header, so if necessary, pad to the end
+	 * of the fifo and then put the header at the beginning of the fifo.
+	 */
+	pad_bytes = gve_tx_fifo_pad_alloc_one_frag(&tx->tx_fifo, hlen);
+	hdr_nfrags = gve_tx_alloc_fifo(&tx->tx_fifo, hlen + pad_bytes,
+				       &info->iov[0]);
+	WARN(!hdr_nfrags, "hdr_nfrags should never be 0!");
+	payload_nfrags = gve_tx_alloc_fifo(&tx->tx_fifo, skb->len - hlen,
+					   &info->iov[payload_iov]);
+
+	gve_tx_fill_pkt_desc(pkt_desc, skb, is_gso, l4_hdr_offset,
+			     1 + payload_nfrags, hlen,
+			     info->iov[hdr_nfrags - 1].iov_offset);
+
+	skb_copy_bits(skb, 0,
+		      tx->tx_fifo.base + info->iov[hdr_nfrags - 1].iov_offset,
+		      hlen);
+	copy_offset = hlen;
+
+	for (i = payload_iov; i < payload_nfrags + payload_iov; i++) {
+		next_idx = (tx->req + 1 + i - payload_iov) & tx->mask;
+		seg_desc = &tx->desc[next_idx];
+
+		gve_tx_fill_seg_desc(seg_desc, skb, is_gso,
+				     info->iov[i].iov_len,
+				     info->iov[i].iov_offset);
+
+		skb_copy_bits(skb, copy_offset,
+			      tx->tx_fifo.base + info->iov[i].iov_offset,
+			      info->iov[i].iov_len);
+		copy_offset += info->iov[i].iov_len;
+	}
+
+	return 1 + payload_nfrags;
+}
+
+netdev_tx_t gve_tx(struct sk_buff *skb, struct net_device *dev)
+{
+	struct gve_priv *priv = netdev_priv(dev);
+	struct gve_tx_ring *tx;
+	int nsegs;
+
+	WARN(skb_get_queue_mapping(skb) > priv->tx_cfg.num_queues,
+	     "skb queue index out of range");
+	tx = &priv->tx[skb_get_queue_mapping(skb)];
+	if (unlikely(gve_maybe_stop_tx(tx, skb))) {
+		/* We need to ring the txq doorbell -- we have stopped the Tx
+		 * queue for want of resources, but prior calls to gve_tx()
+		 * may have added descriptors without ringing the doorbell.
+		 */
+
+		/* Ensure tx descs from a prior gve_tx are visible before
+		 * ringing doorbell.
+		 */
+		dma_wmb();
+		gve_tx_put_doorbell(priv, tx->q_resources, tx->req);
+		return NETDEV_TX_BUSY;
+	}
+	nsegs = gve_tx_add_skb(tx, skb);
+
+	netdev_tx_sent_queue(tx->netdev_txq, skb->len);
+	skb_tx_timestamp(skb);
+
+	/* give packets to NIC */
+	tx->req += nsegs;
+
+	if (!netif_xmit_stopped(tx->netdev_txq) && netdev_xmit_more())
+		return NETDEV_TX_OK;
+
+	/* Ensure tx descs are visible before ringing doorbell */
+	dma_wmb();
+	gve_tx_put_doorbell(priv, tx->q_resources, tx->req);
+	return NETDEV_TX_OK;
+}
+
+#define GVE_TX_START_THRESH	PAGE_SIZE
+
+static int gve_clean_tx_done(struct gve_priv *priv, struct gve_tx_ring *tx,
+			     u32 to_do, bool try_to_wake)
+{
+	struct gve_tx_buffer_state *info;
+	u64 pkts = 0, bytes = 0;
+	size_t space_freed = 0;
+	struct sk_buff *skb;
+	int i, j;
+	u32 idx;
+
+	for (j = 0; j < to_do; j++) {
+		idx = tx->done & tx->mask;
+		netif_info(priv, tx_done, priv->dev,
+			   "[%d] %s: idx=%d (req=%u done=%u)\n",
+			   tx->q_num, __func__, idx, tx->req, tx->done);
+		info = &tx->info[idx];
+		skb = info->skb;
+
+		/* Mark as free */
+		if (skb) {
+			info->skb = NULL;
+			bytes += skb->len;
+			pkts++;
+			dev_consume_skb_any(skb);
+			/* FIFO free */
+			for (i = 0; i < ARRAY_SIZE(info->iov); i++) {
+				space_freed += info->iov[i].iov_len +
+					       info->iov[i].iov_padding;
+				info->iov[i].iov_len = 0;
+				info->iov[i].iov_padding = 0;
+			}
+		}
+		tx->done++;
+	}
+
+	gve_tx_free_fifo(&tx->tx_fifo, space_freed);
+	u64_stats_update_begin(&tx->statss);
+	tx->bytes_done += bytes;
+	tx->pkt_done += pkts;
+	u64_stats_update_end(&tx->statss);
+	netdev_tx_completed_queue(tx->netdev_txq, pkts, bytes);
+
+	/* start the queue if we've stopped it */
+#ifndef CONFIG_BQL
+	/* Make sure that the doorbells are synced */
+	smp_mb();
+#endif
+	if (try_to_wake && netif_tx_queue_stopped(tx->netdev_txq) &&
+	    likely(gve_can_tx(tx, GVE_TX_START_THRESH))) {
+		tx->wake_queue++;
+		netif_tx_wake_queue(tx->netdev_txq);
+	}
+
+	return pkts;
+}
+
+__be32 gve_tx_load_event_counter(struct gve_priv *priv,
+				 struct gve_tx_ring *tx)
+{
+	u32 counter_index = be32_to_cpu((tx->q_resources->counter_index));
+
+	return READ_ONCE(priv->counter_array[counter_index]);
+}
+
+bool gve_tx_poll(struct gve_notify_block *block, int budget)
+{
+	struct gve_priv *priv = block->priv;
+	struct gve_tx_ring *tx = block->tx;
+	bool repoll = false;
+	u32 nic_done;
+	u32 to_do;
+
+	/* If budget is 0, do all the work */
+	if (budget == 0)
+		budget = INT_MAX;
+
+	/* Find out how much work there is to be done */
+	tx->last_nic_done = gve_tx_load_event_counter(priv, tx);
+	nic_done = be32_to_cpu(tx->last_nic_done);
+	if (budget > 0) {
+		/* Do as much work as we have that the budget will
+		 * allow
+		 */
+		to_do = min_t(u32, (nic_done - tx->done), budget);
+		gve_clean_tx_done(priv, tx, to_do, true);
+	}
+	/* If we still have work we want to repoll */
+	repoll |= (nic_done != tx->done);
+	return repoll;
+}