1 files changed, 496 insertions, 149 deletions

diff --git a/drivers/net/ethernet/google/gve/gve_rx.c b/drivers/net/ethernet/google/gve/gve_rx.c
index 9f52e72ff641..021bbf308d68 100644
--- a/drivers/net/ethernet/google/gve/gve_rx.c
+++ b/drivers/net/ethernet/google/gve/gve_rx.c
@@ -1,27 +1,51 @@
 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
 /* Google virtual Ethernet (gve) driver
  *
- * Copyright (C) 2015-2019 Google, Inc.
+ * Copyright (C) 2015-2021 Google, Inc.
  */
 
 #include "gve.h"
 #include "gve_adminq.h"
+#include "gve_utils.h"
 #include <linux/etherdevice.h>
 
-static void gve_rx_remove_from_block(struct gve_priv *priv, int queue_idx)
+static void gve_rx_free_buffer(struct device *dev,
+			       struct gve_rx_slot_page_info *page_info,
+			       union gve_rx_data_slot *data_slot)
 {
-	struct gve_notify_block *block =
-			&priv->ntfy_blocks[gve_rx_idx_to_ntfy(priv, queue_idx)];
+	dma_addr_t dma = (dma_addr_t)(be64_to_cpu(data_slot->addr) &
+				      GVE_DATA_SLOT_ADDR_PAGE_MASK);
 
-	block->rx = NULL;
+	page_ref_sub(page_info->page, page_info->pagecnt_bias - 1);
+	gve_free_page(dev, page_info->page, dma, DMA_FROM_DEVICE);
+}
+
+static void gve_rx_unfill_pages(struct gve_priv *priv, struct gve_rx_ring *rx)
+{
+	u32 slots = rx->mask + 1;
+	int i;
+
+	if (rx->data.raw_addressing) {
+		for (i = 0; i < slots; i++)
+			gve_rx_free_buffer(&priv->pdev->dev, &rx->data.page_info[i],
+					   &rx->data.data_ring[i]);
+	} else {
+		for (i = 0; i < slots; i++)
+			page_ref_sub(rx->data.page_info[i].page,
+				     rx->data.page_info[i].pagecnt_bias - 1);
+		gve_unassign_qpl(priv, rx->data.qpl->id);
+		rx->data.qpl = NULL;
+	}
+	kvfree(rx->data.page_info);
+	rx->data.page_info = NULL;
 }
 
 static void gve_rx_free_ring(struct gve_priv *priv, int idx)
 {
 	struct gve_rx_ring *rx = &priv->rx[idx];
 	struct device *dev = &priv->pdev->dev;
+	u32 slots = rx->mask + 1;
 	size_t bytes;
-	u32 slots;
 
 	gve_rx_remove_from_block(priv, idx);
 
@@ -33,11 +57,8 @@ static void gve_rx_free_ring(struct gve_priv *priv, int idx)
 			  rx->q_resources, rx->q_resources_bus);
 	rx->q_resources = NULL;
 
-	gve_unassign_qpl(priv, rx->data.qpl->id);
-	rx->data.qpl = NULL;
-	kvfree(rx->data.page_info);
+	gve_rx_unfill_pages(priv, rx);
 
-	slots = rx->mask + 1;
 	bytes = sizeof(*rx->data.data_ring) * slots;
 	dma_free_coherent(dev, bytes, rx->data.data_ring,
 			  rx->data.data_bus);
@@ -46,19 +67,39 @@ static void gve_rx_free_ring(struct gve_priv *priv, int idx)
 }
 
 static void gve_setup_rx_buffer(struct gve_rx_slot_page_info *page_info,
-				struct gve_rx_data_slot *slot,
-				dma_addr_t addr, struct page *page)
+			     dma_addr_t addr, struct page *page, __be64 *slot_addr)
 {
 	page_info->page = page;
 	page_info->page_offset = 0;
 	page_info->page_address = page_address(page);
-	slot->qpl_offset = cpu_to_be64(addr);
+	*slot_addr = cpu_to_be64(addr);
+	/* The page already has 1 ref */
+	page_ref_add(page, INT_MAX - 1);
+	page_info->pagecnt_bias = INT_MAX;
+}
+
+static int gve_rx_alloc_buffer(struct gve_priv *priv, struct device *dev,
+			       struct gve_rx_slot_page_info *page_info,
+			       union gve_rx_data_slot *data_slot)
+{
+	struct page *page;
+	dma_addr_t dma;
+	int err;
+
+	err = gve_alloc_page(priv, dev, &page, &dma, DMA_FROM_DEVICE,
+			     GFP_ATOMIC);
+	if (err)
+		return err;
+
+	gve_setup_rx_buffer(page_info, dma, page, &data_slot->addr);
+	return 0;
 }
 
 static int gve_prefill_rx_pages(struct gve_rx_ring *rx)
 {
 	struct gve_priv *priv = rx->gve;
 	u32 slots;
+	int err;
 	int i;
 
 	/* Allocate one page per Rx queue slot. Each page is split into two
@@ -71,27 +112,46 @@ static int gve_prefill_rx_pages(struct gve_rx_ring *rx)
 	if (!rx->data.page_info)
 		return -ENOMEM;
 
-	rx->data.qpl = gve_assign_rx_qpl(priv);
-
+	if (!rx->data.raw_addressing) {
+		rx->data.qpl = gve_assign_rx_qpl(priv);
+		if (!rx->data.qpl) {
+			kvfree(rx->data.page_info);
+			rx->data.page_info = NULL;
+			return -ENOMEM;
+		}
+	}
 	for (i = 0; i < slots; i++) {
-		struct page *page = rx->data.qpl->pages[i];
-		dma_addr_t addr = i * PAGE_SIZE;
+		if (!rx->data.raw_addressing) {
+			struct page *page = rx->data.qpl->pages[i];
+			dma_addr_t addr = i * PAGE_SIZE;
 
-		gve_setup_rx_buffer(&rx->data.page_info[i],
-				    &rx->data.data_ring[i], addr, page);
+			gve_setup_rx_buffer(&rx->data.page_info[i], addr, page,
+					    &rx->data.data_ring[i].qpl_offset);
+			continue;
+		}
+		err = gve_rx_alloc_buffer(priv, &priv->pdev->dev, &rx->data.page_info[i],
+					  &rx->data.data_ring[i]);
+		if (err)
+			goto alloc_err;
 	}
 
 	return slots;
+alloc_err:
+	while (i--)
+		gve_rx_free_buffer(&priv->pdev->dev,
+				   &rx->data.page_info[i],
+				   &rx->data.data_ring[i]);
+	return err;
 }
 
-static void gve_rx_add_to_block(struct gve_priv *priv, int queue_idx)
+static void gve_rx_ctx_clear(struct gve_rx_ctx *ctx)
 {
-	u32 ntfy_idx = gve_rx_idx_to_ntfy(priv, queue_idx);
-	struct gve_notify_block *block = &priv->ntfy_blocks[ntfy_idx];
-	struct gve_rx_ring *rx = &priv->rx[queue_idx];
-
-	block->rx = rx;
-	rx->ntfy_id = ntfy_idx;
+	ctx->curr_frag_cnt = 0;
+	ctx->total_expected_size = 0;
+	ctx->expected_frag_cnt = 0;
+	ctx->skb_head = NULL;
+	ctx->skb_tail = NULL;
+	ctx->reuse_frags = false;
 }
 
 static int gve_rx_alloc_ring(struct gve_priv *priv, int idx)
@@ -110,8 +170,9 @@ static int gve_rx_alloc_ring(struct gve_priv *priv, int idx)
 	rx->gve = priv;
 	rx->q_num = idx;
 
-	slots = priv->rx_pages_per_qpl;
+	slots = priv->rx_data_slot_cnt;
 	rx->mask = slots - 1;
+	rx->data.raw_addressing = priv->queue_format == GVE_GQI_RDA_FORMAT;
 
 	/* alloc rx data ring */
 	bytes = sizeof(*rx->data.data_ring) * slots;
@@ -156,9 +217,15 @@ static int gve_rx_alloc_ring(struct gve_priv *priv, int idx)
 		err = -ENOMEM;
 		goto abort_with_q_resources;
 	}
-	rx->mask = slots - 1;
 	rx->cnt = 0;
+	rx->db_threshold = priv->rx_desc_cnt / 2;
 	rx->desc.seqno = 1;
+
+	/* Allocating half-page buffers allows page-flipping which is faster
+	 * than copying or allocating new pages.
+	 */
+	rx->packet_buffer_size = PAGE_SIZE / 2;
+	gve_rx_ctx_clear(&rx->ctx);
 	gve_rx_add_to_block(priv, idx);
 
 	return 0;
@@ -168,7 +235,7 @@ abort_with_q_resources:
 			  rx->q_resources, rx->q_resources_bus);
 	rx->q_resources = NULL;
 abort_filled:
-	kvfree(rx->data.page_info);
+	gve_rx_unfill_pages(priv, rx);
 abort_with_slots:
 	bytes = sizeof(*rx->data.data_ring) * slots;
 	dma_free_coherent(hdev, bytes, rx->data.data_ring, rx->data.data_bus);
@@ -201,7 +268,7 @@ int gve_rx_alloc_rings(struct gve_priv *priv)
 	return err;
 }
 
-void gve_rx_free_rings(struct gve_priv *priv)
+void gve_rx_free_rings_gqi(struct gve_priv *priv)
 {
 	int i;
 
@@ -225,144 +292,346 @@ static enum pkt_hash_types gve_rss_type(__be16 pkt_flags)
 	return PKT_HASH_TYPE_L2;
 }
 
-static struct sk_buff *gve_rx_copy(struct net_device *dev,
-				   struct napi_struct *napi,
-				   struct gve_rx_slot_page_info *page_info,
-				   u16 len)
+static u16 gve_rx_ctx_padding(struct gve_rx_ctx *ctx)
 {
-	struct sk_buff *skb = napi_alloc_skb(napi, len);
-	void *va = page_info->page_address + GVE_RX_PAD +
-		   page_info->page_offset;
+	return (ctx->curr_frag_cnt == 0) ? GVE_RX_PAD : 0;
+}
 
-	if (unlikely(!skb))
-		return NULL;
+static struct sk_buff *gve_rx_add_frags(struct napi_struct *napi,
+					struct gve_rx_slot_page_info *page_info,
+					u16 packet_buffer_size, u16 len,
+					struct gve_rx_ctx *ctx)
+{
+	u32 offset = page_info->page_offset +  gve_rx_ctx_padding(ctx);
+	struct sk_buff *skb;
+
+	if (!ctx->skb_head)
+		ctx->skb_head = napi_get_frags(napi);
 
-	__skb_put(skb, len);
+	if (unlikely(!ctx->skb_head))
+		return NULL;
 
-	skb_copy_to_linear_data(skb, va, len);
+	skb = ctx->skb_head;
+	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page_info->page,
+			offset, len, packet_buffer_size);
 
-	skb->protocol = eth_type_trans(skb, dev);
 	return skb;
 }
 
-static struct sk_buff *gve_rx_add_frags(struct net_device *dev,
-					struct napi_struct *napi,
-					struct gve_rx_slot_page_info *page_info,
-					u16 len)
+static void gve_rx_flip_buff(struct gve_rx_slot_page_info *page_info, __be64 *slot_addr)
+{
+	const __be64 offset = cpu_to_be64(PAGE_SIZE / 2);
+
+	/* "flip" to other packet buffer on this page */
+	page_info->page_offset ^= PAGE_SIZE / 2;
+	*(slot_addr) ^= offset;
+}
+
+static int gve_rx_can_recycle_buffer(struct gve_rx_slot_page_info *page_info)
+{
+	int pagecount = page_count(page_info->page);
+
+	/* This page is not being used by any SKBs - reuse */
+	if (pagecount == page_info->pagecnt_bias)
+		return 1;
+	/* This page is still being used by an SKB - we can't reuse */
+	else if (pagecount > page_info->pagecnt_bias)
+		return 0;
+	WARN(pagecount < page_info->pagecnt_bias,
+	     "Pagecount should never be less than the bias.");
+	return -1;
+}
+
+static struct sk_buff *
+gve_rx_raw_addressing(struct device *dev, struct net_device *netdev,
+		      struct gve_rx_slot_page_info *page_info, u16 len,
+		      struct napi_struct *napi,
+		      union gve_rx_data_slot *data_slot,
+		      u16 packet_buffer_size, struct gve_rx_ctx *ctx)
 {
-	struct sk_buff *skb = napi_get_frags(napi);
+	struct sk_buff *skb = gve_rx_add_frags(napi, page_info, packet_buffer_size, len, ctx);
 
-	if (unlikely(!skb))
+	if (!skb)
 		return NULL;
 
-	skb_add_rx_frag(skb, 0, page_info->page,
-			page_info->page_offset +
-			GVE_RX_PAD, len, PAGE_SIZE / 2);
+	/* Optimistically stop the kernel from freeing the page.
+	 * We will check again in refill to determine if we need to alloc a
+	 * new page.
+	 */
+	gve_dec_pagecnt_bias(page_info);
 
 	return skb;
 }
 
-static void gve_rx_flip_buff(struct gve_rx_slot_page_info *page_info,
-			     struct gve_rx_data_slot *data_ring)
+static struct sk_buff *
+gve_rx_qpl(struct device *dev, struct net_device *netdev,
+	   struct gve_rx_ring *rx, struct gve_rx_slot_page_info *page_info,
+	   u16 len, struct napi_struct *napi,
+	   union gve_rx_data_slot *data_slot)
 {
-	u64 addr = be64_to_cpu(data_ring->qpl_offset);
+	struct gve_rx_ctx *ctx = &rx->ctx;
+	struct sk_buff *skb;
 
-	page_info->page_offset ^= PAGE_SIZE / 2;
-	addr ^= PAGE_SIZE / 2;
-	data_ring->qpl_offset = cpu_to_be64(addr);
+	/* if raw_addressing mode is not enabled gvnic can only receive into
+	 * registered segments. If the buffer can't be recycled, our only
+	 * choice is to copy the data out of it so that we can return it to the
+	 * device.
+	 */
+	if (ctx->reuse_frags) {
+		skb = gve_rx_add_frags(napi, page_info, rx->packet_buffer_size, len, ctx);
+		/* No point in recycling if we didn't get the skb */
+		if (skb) {
+			/* Make sure that the page isn't freed. */
+			gve_dec_pagecnt_bias(page_info);
+			gve_rx_flip_buff(page_info, &data_slot->qpl_offset);
+		}
+	} else {
+		const u16 padding = gve_rx_ctx_padding(ctx);
+
+		skb = gve_rx_copy(netdev, napi, page_info, len, padding, ctx);
+		if (skb) {
+			u64_stats_update_begin(&rx->statss);
+			rx->rx_frag_copy_cnt++;
+			u64_stats_update_end(&rx->statss);
+		}
+	}
+	return skb;
+}
+
+#define GVE_PKTCONT_BIT_IS_SET(x) (GVE_RXF_PKT_CONT & (x))
+static u16 gve_rx_get_fragment_size(struct gve_rx_ctx *ctx, struct gve_rx_desc *desc)
+{
+	return be16_to_cpu(desc->len) - gve_rx_ctx_padding(ctx);
 }
 
-static bool gve_rx(struct gve_rx_ring *rx, struct gve_rx_desc *rx_desc,
-		   netdev_features_t feat, u32 idx)
+static bool gve_rx_ctx_init(struct gve_rx_ctx *ctx, struct gve_rx_ring *rx)
 {
+	bool qpl_mode = !rx->data.raw_addressing, packet_size_error = false;
+	bool buffer_error = false, desc_error = false, seqno_error = false;
 	struct gve_rx_slot_page_info *page_info;
 	struct gve_priv *priv = rx->gve;
-	struct napi_struct *napi = &priv->ntfy_blocks[rx->ntfy_id].napi;
-	struct net_device *dev = priv->dev;
-	struct sk_buff *skb;
-	int pagecount;
-	u16 len;
+	u32 idx = rx->cnt & rx->mask;
+	bool reuse_frags, can_flip;
+	struct gve_rx_desc *desc;
+	u16 packet_size = 0;
+	u16 n_frags = 0;
+	int recycle;
 
-	/* drop this packet */
-	if (unlikely(rx_desc->flags_seq & GVE_RXF_ERR))
-		return true;
+	/** In QPL mode, we only flip buffers when all buffers containing the packet
+	 * can be flipped. RDA can_flip decisions will be made later, per frag.
+	 */
+	can_flip = qpl_mode;
+	reuse_frags = can_flip;
+	do {
+		u16 frag_size;
+
+		n_frags++;
+		desc = &rx->desc.desc_ring[idx];
+		desc_error = unlikely(desc->flags_seq & GVE_RXF_ERR) || desc_error;
+		if (GVE_SEQNO(desc->flags_seq) != rx->desc.seqno) {
+			seqno_error = true;
+			netdev_warn(priv->dev,
+				    "RX seqno error: want=%d, got=%d, dropping packet and scheduling reset.",
+				    rx->desc.seqno, GVE_SEQNO(desc->flags_seq));
+		}
+		frag_size = be16_to_cpu(desc->len);
+		packet_size += frag_size;
+		if (frag_size > rx->packet_buffer_size) {
+			packet_size_error = true;
+			netdev_warn(priv->dev,
+				    "RX fragment error: packet_buffer_size=%d, frag_size=%d, dropping packet.",
+				    rx->packet_buffer_size, be16_to_cpu(desc->len));
+		}
+		page_info = &rx->data.page_info[idx];
+		if (can_flip) {
+			recycle = gve_rx_can_recycle_buffer(page_info);
+			reuse_frags = reuse_frags && recycle > 0;
+			buffer_error = buffer_error || unlikely(recycle < 0);
+		}
+		idx = (idx + 1) & rx->mask;
+		rx->desc.seqno = gve_next_seqno(rx->desc.seqno);
+	} while (GVE_PKTCONT_BIT_IS_SET(desc->flags_seq));
 
-	len = be16_to_cpu(rx_desc->len) - GVE_RX_PAD;
-	page_info = &rx->data.page_info[idx];
-	dma_sync_single_for_cpu(&priv->pdev->dev, rx->data.qpl->page_buses[idx],
-				PAGE_SIZE, DMA_FROM_DEVICE);
+	prefetch(rx->desc.desc_ring + idx);
 
-	/* gvnic can only receive into registered segments. If the buffer
-	 * can't be recycled, our only choice is to copy the data out of
-	 * it so that we can return it to the device.
-	 */
+	ctx->curr_frag_cnt = 0;
+	ctx->total_expected_size = packet_size - GVE_RX_PAD;
+	ctx->expected_frag_cnt = n_frags;
+	ctx->skb_head = NULL;
+	ctx->reuse_frags = reuse_frags;
 
-	if (PAGE_SIZE == 4096) {
-		if (len <= priv->rx_copybreak) {
-			/* Just copy small packets */
-			skb = gve_rx_copy(dev, napi, page_info, len);
-			goto have_skb;
-		}
-		if (unlikely(!gve_can_recycle_pages(dev))) {
-			skb = gve_rx_copy(dev, napi, page_info, len);
-			goto have_skb;
+	if (ctx->expected_frag_cnt > 1) {
+		u64_stats_update_begin(&rx->statss);
+		rx->rx_cont_packet_cnt++;
+		u64_stats_update_end(&rx->statss);
+	}
+	if (ctx->total_expected_size > priv->rx_copybreak && !ctx->reuse_frags && qpl_mode) {
+		u64_stats_update_begin(&rx->statss);
+		rx->rx_copied_pkt++;
+		u64_stats_update_end(&rx->statss);
+	}
+
+	if (unlikely(buffer_error || seqno_error || packet_size_error)) {
+		gve_schedule_reset(priv);
+		return false;
+	}
+
+	if (unlikely(desc_error)) {
+		u64_stats_update_begin(&rx->statss);
+		rx->rx_desc_err_dropped_pkt++;
+		u64_stats_update_end(&rx->statss);
+		return false;
+	}
+	return true;
+}
+
+static struct sk_buff *gve_rx_skb(struct gve_priv *priv, struct gve_rx_ring *rx,
+				  struct gve_rx_slot_page_info *page_info, struct napi_struct *napi,
+				  u16 len, union gve_rx_data_slot *data_slot)
+{
+	struct net_device *netdev = priv->dev;
+	struct gve_rx_ctx *ctx = &rx->ctx;
+	struct sk_buff *skb = NULL;
+
+	if (len <= priv->rx_copybreak && ctx->expected_frag_cnt == 1) {
+		/* Just copy small packets */
+		skb = gve_rx_copy(netdev, napi, page_info, len, GVE_RX_PAD, ctx);
+		if (skb) {
+			u64_stats_update_begin(&rx->statss);
+			rx->rx_copied_pkt++;
+			rx->rx_frag_copy_cnt++;
+			rx->rx_copybreak_pkt++;
+			u64_stats_update_end(&rx->statss);
 		}
-		pagecount = page_count(page_info->page);
-		if (pagecount == 1) {
-			/* No part of this page is used by any SKBs; we attach
-			 * the page fragment to a new SKB and pass it up the
-			 * stack.
-			 */
-			skb = gve_rx_add_frags(dev, napi, page_info, len);
-			if (!skb)
-				return true;
-			/* Make sure the kernel stack can't release the page */
-			get_page(page_info->page);
-			/* "flip" to other packet buffer on this page */
-			gve_rx_flip_buff(page_info, &rx->data.data_ring[idx]);
-		} else if (pagecount >= 2) {
-			/* We have previously passed the other half of this
-			 * page up the stack, but it has not yet been freed.
-			 */
-			skb = gve_rx_copy(dev, napi, page_info, len);
+	} else {
+		if (rx->data.raw_addressing) {
+			int recycle = gve_rx_can_recycle_buffer(page_info);
+
+			if (unlikely(recycle < 0)) {
+				gve_schedule_reset(priv);
+				return NULL;
+			}
+			page_info->can_flip = recycle;
+			if (page_info->can_flip) {
+				u64_stats_update_begin(&rx->statss);
+				rx->rx_frag_flip_cnt++;
+				u64_stats_update_end(&rx->statss);
+			}
+			skb = gve_rx_raw_addressing(&priv->pdev->dev, netdev,
+						    page_info, len, napi,
+						    data_slot,
+						    rx->packet_buffer_size, ctx);
 		} else {
-			WARN(pagecount < 1, "Pagecount should never be < 1");
-			return false;
+			if (ctx->reuse_frags) {
+				u64_stats_update_begin(&rx->statss);
+				rx->rx_frag_flip_cnt++;
+				u64_stats_update_end(&rx->statss);
+			}
+			skb = gve_rx_qpl(&priv->pdev->dev, netdev, rx,
+					 page_info, len, napi, data_slot);
 		}
-	} else {
-		skb = gve_rx_copy(dev, napi, page_info, len);
 	}
+	return skb;
+}
 
-have_skb:
-	/* We didn't manage to allocate an skb but we haven't had any
-	 * reset worthy failures.
-	 */
-	if (!skb)
-		return true;
+static bool gve_rx(struct gve_rx_ring *rx, netdev_features_t feat,
+		   u64 *packet_size_bytes, u32 *work_done)
+{
+	struct gve_rx_slot_page_info *page_info;
+	struct gve_rx_ctx *ctx = &rx->ctx;
+	union gve_rx_data_slot *data_slot;
+	struct gve_priv *priv = rx->gve;
+	struct gve_rx_desc *first_desc;
+	struct sk_buff *skb = NULL;
+	struct gve_rx_desc *desc;
+	struct napi_struct *napi;
+	dma_addr_t page_bus;
+	u32 work_cnt = 0;
+	void *va;
+	u32 idx;
+	u16 len;
+
+	idx = rx->cnt & rx->mask;
+	first_desc = &rx->desc.desc_ring[idx];
+	desc = first_desc;
+	napi = &priv->ntfy_blocks[rx->ntfy_id].napi;
+
+	if (unlikely(!gve_rx_ctx_init(ctx, rx)))
+		goto skb_alloc_fail;
+
+	while (ctx->curr_frag_cnt < ctx->expected_frag_cnt) {
+		/* Prefetch two packet buffers ahead, we will need it soon. */
+		page_info = &rx->data.page_info[(idx + 2) & rx->mask];
+		va = page_info->page_address + page_info->page_offset;
+
+		prefetch(page_info->page); /* Kernel page struct. */
+		prefetch(va);              /* Packet header. */
+		prefetch(va + 64);         /* Next cacheline too. */
+
+		len = gve_rx_get_fragment_size(ctx, desc);
+
+		page_info = &rx->data.page_info[idx];
+		data_slot = &rx->data.data_ring[idx];
+		page_bus = rx->data.raw_addressing ?
+			   be64_to_cpu(data_slot->addr) - page_info->page_offset :
+			   rx->data.qpl->page_buses[idx];
+		dma_sync_single_for_cpu(&priv->pdev->dev, page_bus, PAGE_SIZE, DMA_FROM_DEVICE);
+
+		skb = gve_rx_skb(priv, rx, page_info, napi, len, data_slot);
+		if (!skb) {
+			u64_stats_update_begin(&rx->statss);
+			rx->rx_skb_alloc_fail++;
+			u64_stats_update_end(&rx->statss);
+			goto skb_alloc_fail;
+		}
+
+		ctx->curr_frag_cnt++;
+		rx->cnt++;
+		idx = rx->cnt & rx->mask;
+		work_cnt++;
+		desc = &rx->desc.desc_ring[idx];
+	}
 
 	if (likely(feat & NETIF_F_RXCSUM)) {
 		/* NIC passes up the partial sum */
-		if (rx_desc->csum)
+		if (first_desc->csum)
 			skb->ip_summed = CHECKSUM_COMPLETE;
 		else
 			skb->ip_summed = CHECKSUM_NONE;
-		skb->csum = csum_unfold(rx_desc->csum);
+		skb->csum = csum_unfold(first_desc->csum);
 	}
 
 	/* parse flags & pass relevant info up */
 	if (likely(feat & NETIF_F_RXHASH) &&
-	    gve_needs_rss(rx_desc->flags_seq))
-		skb_set_hash(skb, be32_to_cpu(rx_desc->rss_hash),
-			     gve_rss_type(rx_desc->flags_seq));
+	    gve_needs_rss(first_desc->flags_seq))
+		skb_set_hash(skb, be32_to_cpu(first_desc->rss_hash),
+			     gve_rss_type(first_desc->flags_seq));
 
+	*packet_size_bytes = skb->len + (skb->protocol ? ETH_HLEN : 0);
+	*work_done = work_cnt;
+	skb_record_rx_queue(skb, rx->q_num);
 	if (skb_is_nonlinear(skb))
 		napi_gro_frags(napi);
 	else
 		napi_gro_receive(napi, skb);
+
+	gve_rx_ctx_clear(ctx);
 	return true;
+
+skb_alloc_fail:
+	if (napi->skb)
+		napi_free_frags(napi);
+	*packet_size_bytes = 0;
+	*work_done = ctx->expected_frag_cnt;
+	while (ctx->curr_frag_cnt < ctx->expected_frag_cnt) {
+		rx->cnt++;
+		ctx->curr_frag_cnt++;
+	}
+	gve_rx_ctx_clear(ctx);
+	return false;
 }
 
-static bool gve_rx_work_pending(struct gve_rx_ring *rx)
+bool gve_rx_work_pending(struct gve_rx_ring *rx)
 {
 	struct gve_rx_desc *desc;
 	__be16 flags_seq;
@@ -372,25 +641,82 @@ static bool gve_rx_work_pending(struct gve_rx_ring *rx)
 	desc = rx->desc.desc_ring + next_idx;
 
 	flags_seq = desc->flags_seq;
-	/* Make sure we have synchronized the seq no with the device */
-	smp_rmb();
 
 	return (GVE_SEQNO(flags_seq) == rx->desc.seqno);
 }
 
-bool gve_clean_rx_done(struct gve_rx_ring *rx, int budget,
-		       netdev_features_t feat)
+static bool gve_rx_refill_buffers(struct gve_priv *priv, struct gve_rx_ring *rx)
 {
+	int refill_target = rx->mask + 1;
+	u32 fill_cnt = rx->fill_cnt;
+
+	while (fill_cnt - rx->cnt < refill_target) {
+		struct gve_rx_slot_page_info *page_info;
+		u32 idx = fill_cnt & rx->mask;
+
+		page_info = &rx->data.page_info[idx];
+		if (page_info->can_flip) {
+			/* The other half of the page is free because it was
+			 * free when we processed the descriptor. Flip to it.
+			 */
+			union gve_rx_data_slot *data_slot =
+						&rx->data.data_ring[idx];
+
+			gve_rx_flip_buff(page_info, &data_slot->addr);
+			page_info->can_flip = 0;
+		} else {
+			/* It is possible that the networking stack has already
+			 * finished processing all outstanding packets in the buffer
+			 * and it can be reused.
+			 * Flipping is unnecessary here - if the networking stack still
+			 * owns half the page it is impossible to tell which half. Either
+			 * the whole page is free or it needs to be replaced.
+			 */
+			int recycle = gve_rx_can_recycle_buffer(page_info);
+
+			if (recycle < 0) {
+				if (!rx->data.raw_addressing)
+					gve_schedule_reset(priv);
+				return false;
+			}
+			if (!recycle) {
+				/* We can't reuse the buffer - alloc a new one*/
+				union gve_rx_data_slot *data_slot =
+						&rx->data.data_ring[idx];
+				struct device *dev = &priv->pdev->dev;
+				gve_rx_free_buffer(dev, page_info, data_slot);
+				page_info->page = NULL;
+				if (gve_rx_alloc_buffer(priv, dev, page_info,
+							data_slot)) {
+					u64_stats_update_begin(&rx->statss);
+					rx->rx_buf_alloc_fail++;
+					u64_stats_update_end(&rx->statss);
+					break;
+				}
+			}
+		}
+		fill_cnt++;
+	}
+	rx->fill_cnt = fill_cnt;
+	return true;
+}
+
+static int gve_clean_rx_done(struct gve_rx_ring *rx, int budget,
+			     netdev_features_t feat)
+{
+	u32 work_done = 0, total_packet_cnt = 0, ok_packet_cnt = 0;
 	struct gve_priv *priv = rx->gve;
+	u32 idx = rx->cnt & rx->mask;
 	struct gve_rx_desc *desc;
-	u32 cnt = rx->cnt;
-	u32 idx = cnt & rx->mask;
-	u32 work_done = 0;
 	u64 bytes = 0;
 
-	desc = rx->desc.desc_ring + idx;
+	desc = &rx->desc.desc_ring[idx];
 	while ((GVE_SEQNO(desc->flags_seq) == rx->desc.seqno) &&
 	       work_done < budget) {
+		u64 packet_size_bytes = 0;
+		u32 work_cnt = 0;
+		bool dropped;
+
 		netif_info(priv, rx_status, priv->dev,
 			   "[%d] idx=%d desc=%p desc->flags_seq=0x%x\n",
 			   rx->q_num, idx, desc, desc->flags_seq);
@@ -398,35 +724,57 @@ bool gve_clean_rx_done(struct gve_rx_ring *rx, int budget,
 			   "[%d] seqno=%d rx->desc.seqno=%d\n",
 			   rx->q_num, GVE_SEQNO(desc->flags_seq),
 			   rx->desc.seqno);
-		bytes += be16_to_cpu(desc->len) - GVE_RX_PAD;
-		if (!gve_rx(rx, desc, feat, idx))
-			gve_schedule_reset(priv);
-		cnt++;
-		idx = cnt & rx->mask;
-		desc = rx->desc.desc_ring + idx;
-		rx->desc.seqno = gve_next_seqno(rx->desc.seqno);
-		work_done++;
+
+		dropped = !gve_rx(rx, feat, &packet_size_bytes, &work_cnt);
+		if (!dropped) {
+			bytes += packet_size_bytes;
+			ok_packet_cnt++;
+		}
+		total_packet_cnt++;
+		idx = rx->cnt & rx->mask;
+		desc = &rx->desc.desc_ring[idx];
+		work_done += work_cnt;
 	}
 
-	if (!work_done)
-		return false;
+	if (!work_done && rx->fill_cnt - rx->cnt > rx->db_threshold)
+		return 0;
 
-	u64_stats_update_begin(&rx->statss);
-	rx->rpackets += work_done;
-	rx->rbytes += bytes;
-	u64_stats_update_end(&rx->statss);
-	rx->cnt = cnt;
-	rx->fill_cnt += work_done;
+	if (work_done) {
+		u64_stats_update_begin(&rx->statss);
+		rx->rpackets += ok_packet_cnt;
+		rx->rbytes += bytes;
+		u64_stats_update_end(&rx->statss);
+	}
+
+	/* restock ring slots */
+	if (!rx->data.raw_addressing) {
+		/* In QPL mode buffs are refilled as the desc are processed */
+		rx->fill_cnt += work_done;
+	} else if (rx->fill_cnt - rx->cnt <= rx->db_threshold) {
+		/* In raw addressing mode buffs are only refilled if the avail
+		 * falls below a threshold.
+		 */
+		if (!gve_rx_refill_buffers(priv, rx))
+			return 0;
+
+		/* If we were not able to completely refill buffers, we'll want
+		 * to schedule this queue for work again to refill buffers.
+		 */
+		if (rx->fill_cnt - rx->cnt <= rx->db_threshold) {
+			gve_rx_write_doorbell(priv, rx);
+			return budget;
+		}
+	}
 
 	gve_rx_write_doorbell(priv, rx);
-	return gve_rx_work_pending(rx);
+	return total_packet_cnt;
 }
 
-bool gve_rx_poll(struct gve_notify_block *block, int budget)
+int gve_rx_poll(struct gve_notify_block *block, int budget)
 {
 	struct gve_rx_ring *rx = block->rx;
 	netdev_features_t feat;
-	bool repoll = false;
+	int work_done = 0;
 
 	feat = block->napi.dev->features;
 
@@ -435,8 +783,7 @@ bool gve_rx_poll(struct gve_notify_block *block, int budget)
 		budget = INT_MAX;
 
 	if (budget > 0)
-		repoll |= gve_clean_rx_done(rx, budget, feat);
-	else
-		repoll |= gve_rx_work_pending(rx);
-	return repoll;
+		work_done = gve_clean_rx_done(rx, budget, feat);
+
+	return work_done;
 }