Merge branch 'mlx4-order-0-allocations-and-page-recycling'

Eric Dumazet says:

====================
mlx4: order-0 allocations and page recycling

As mentioned half a year ago, we better switch mlx4 driver to order-0
allocations and page recycling.

This reduces vulnerability surface thanks to better skb->truesize
tracking and provides better performance in most cases.
(33 Gbit for one TCP flow on my lab hosts)

I will provide for linux-4.13 a patch on top of this series,
trying to improve data locality as described in
https://www.spinics.net/lists/netdev/msg422258.html

v2 provides an ethtool -S new counter (rx_alloc_pages) and
code factorization, plus Tariq fix.

v3 includes various fixes based on Tariq tests and feedback
from Saeed and Tariq.

v4 rebased on net-next for inclusion in linux-4.12, as requested
by Tariq.

Worth noting this patch series deletes ~250 lines of code ;)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_ethtool.c

@@ -117,7 +117,7 @@ static const char main_strings[][ETH_GSTRING_LEN] = {
 	/* port statistics */
 	"tso_packets",
 	"xmit_more",
-	"queue_stopped", "wake_queue", "tx_timeout", "rx_alloc_failed",
+	"queue_stopped", "wake_queue", "tx_timeout", "rx_alloc_pages",
 	"rx_csum_good", "rx_csum_none", "rx_csum_complete", "tx_chksum_offload",
 
 	/* pf statistics */

drivers/net/ethernet/mellanox/mlx4/en_port.c

@@ -213,6 +213,7 @@ int mlx4_en_DUMP_ETH_STATS(struct mlx4_en_dev *mdev, u8 port, u8 reset)
 	priv->port_stats.rx_chksum_good = 0;
 	priv->port_stats.rx_chksum_none = 0;
 	priv->port_stats.rx_chksum_complete = 0;
+	priv->port_stats.rx_alloc_pages = 0;
 	priv->xdp_stats.rx_xdp_drop    = 0;
 	priv->xdp_stats.rx_xdp_tx      = 0;
 	priv->xdp_stats.rx_xdp_tx_full = 0;
@@ -223,6 +224,7 @@ int mlx4_en_DUMP_ETH_STATS(struct mlx4_en_dev *mdev, u8 port, u8 reset)
 		priv->port_stats.rx_chksum_good += READ_ONCE(ring->csum_ok);
 		priv->port_stats.rx_chksum_none += READ_ONCE(ring->csum_none);
 		priv->port_stats.rx_chksum_complete += READ_ONCE(ring->csum_complete);
+		priv->port_stats.rx_alloc_pages += READ_ONCE(ring->rx_alloc_pages);
 		priv->xdp_stats.rx_xdp_drop	+= READ_ONCE(ring->xdp_drop);
 		priv->xdp_stats.rx_xdp_tx	+= READ_ONCE(ring->xdp_tx);
 		priv->xdp_stats.rx_xdp_tx_full	+= READ_ONCE(ring->xdp_tx_full);

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -50,173 +50,62 @@
 
 #include "mlx4_en.h"
 
-static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
-			    struct mlx4_en_rx_alloc *page_alloc,
-			    const struct mlx4_en_frag_info *frag_info,
-			    gfp_t _gfp)
+static int mlx4_alloc_page(struct mlx4_en_priv *priv,
+			   struct mlx4_en_rx_alloc *frag,
+			   gfp_t gfp)
 {
-	int order;
 	struct page *page;
 	dma_addr_t dma;
 
-	for (order = frag_info->order; ;) {
-		gfp_t gfp = _gfp;
-
-		if (order)
-			gfp |= __GFP_COMP | __GFP_NOWARN | __GFP_NOMEMALLOC;
-		page = alloc_pages(gfp, order);
-		if (likely(page))
-			break;
-		if (--order < 0 ||
-		    ((PAGE_SIZE << order) < frag_info->frag_size))
+	page = alloc_page(gfp);
+	if (unlikely(!page))
 		return -ENOMEM;
-	}
-	dma = dma_map_page(priv->ddev, page, 0, PAGE_SIZE << order,
-			   frag_info->dma_dir);
+	dma = dma_map_page(priv->ddev, page, 0, PAGE_SIZE, priv->dma_dir);
 	if (unlikely(dma_mapping_error(priv->ddev, dma))) {
-		put_page(page);
+		__free_page(page);
 		return -ENOMEM;
 	}
-	page_alloc->page_size = PAGE_SIZE << order;
-	page_alloc->page = page;
-	page_alloc->dma = dma;
-	page_alloc->page_offset = 0;
-	/* Not doing get_page() for each frag is a big win
-	 * on asymetric workloads. Note we can not use atomic_set().
-	 */
-	page_ref_add(page, page_alloc->page_size / frag_info->frag_stride - 1);
+	frag->page = page;
+	frag->dma = dma;
+	frag->page_offset = priv->rx_headroom;
 	return 0;
 }
 
 static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
+			       struct mlx4_en_rx_ring *ring,
 			       struct mlx4_en_rx_desc *rx_desc,
 			       struct mlx4_en_rx_alloc *frags,
-			       struct mlx4_en_rx_alloc *ring_alloc,
 			       gfp_t gfp)
 {
-	struct mlx4_en_rx_alloc page_alloc[MLX4_EN_MAX_RX_FRAGS];
-	const struct mlx4_en_frag_info *frag_info;
-	struct page *page;
 	int i;
 
-	for (i = 0; i < priv->num_frags; i++) {
-		frag_info = &priv->frag_info[i];
-		page_alloc[i] = ring_alloc[i];
-		page_alloc[i].page_offset += frag_info->frag_stride;
-
-		if (page_alloc[i].page_offset + frag_info->frag_stride <=
-		    ring_alloc[i].page_size)
-			continue;
-
-		if (unlikely(mlx4_alloc_pages(priv, &page_alloc[i],
-					      frag_info, gfp)))
-			goto out;
-	}
-
-	for (i = 0; i < priv->num_frags; i++) {
-		frags[i] = ring_alloc[i];
-		frags[i].page_offset += priv->frag_info[i].rx_headroom;
-		rx_desc->data[i].addr = cpu_to_be64(frags[i].dma +
-						    frags[i].page_offset);
-		ring_alloc[i] = page_alloc[i];
-	}
-
-	return 0;
-
-out:
-	while (i--) {
-		if (page_alloc[i].page != ring_alloc[i].page) {
-			dma_unmap_page(priv->ddev, page_alloc[i].dma,
-				page_alloc[i].page_size,
-				priv->frag_info[i].dma_dir);
-			page = page_alloc[i].page;
-			/* Revert changes done by mlx4_alloc_pages */
-			page_ref_sub(page, page_alloc[i].page_size /
-					   priv->frag_info[i].frag_stride - 1);
-			put_page(page);
-		}
-	}
+	for (i = 0; i < priv->num_frags; i++, frags++) {
+		if (!frags->page) {
+			if (mlx4_alloc_page(priv, frags, gfp))
 				return -ENOMEM;
-}
-
-static void mlx4_en_free_frag(struct mlx4_en_priv *priv,
-			      struct mlx4_en_rx_alloc *frags,
-			      int i)
-{
-	const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
-	u32 next_frag_end = frags[i].page_offset + 2 * frag_info->frag_stride;
-
-
-	if (next_frag_end > frags[i].page_size)
-		dma_unmap_page(priv->ddev, frags[i].dma, frags[i].page_size,
-			       frag_info->dma_dir);
-
-	if (frags[i].page)
-		put_page(frags[i].page);
-}
-
-static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
-				  struct mlx4_en_rx_ring *ring)
-{
-	int i;
-	struct mlx4_en_rx_alloc *page_alloc;
-
-	for (i = 0; i < priv->num_frags; i++) {
-		const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
-
-		if (mlx4_alloc_pages(priv, &ring->page_alloc[i],
-				     frag_info, GFP_KERNEL | __GFP_COLD))
-			goto out;
-
-		en_dbg(DRV, priv, "  frag %d allocator: - size:%d frags:%d\n",
-		       i, ring->page_alloc[i].page_size,
-		       page_ref_count(ring->page_alloc[i].page));
+			ring->rx_alloc_pages++;
 		}
-	return 0;
-
-out:
-	while (i--) {
-		struct page *page;
-
-		page_alloc = &ring->page_alloc[i];
-		dma_unmap_page(priv->ddev, page_alloc->dma,
-			       page_alloc->page_size,
-			       priv->frag_info[i].dma_dir);
-		page = page_alloc->page;
-		/* Revert changes done by mlx4_alloc_pages */
-		page_ref_sub(page, page_alloc->page_size /
-				   priv->frag_info[i].frag_stride - 1);
-		put_page(page);
-		page_alloc->page = NULL;
+		rx_desc->data[i].addr = cpu_to_be64(frags->dma +
+						    frags->page_offset);
 	}
-	return -ENOMEM;
+	return 0;
 }
 
-static void mlx4_en_destroy_allocator(struct mlx4_en_priv *priv,
-				      struct mlx4_en_rx_ring *ring)
+static void mlx4_en_free_frag(const struct mlx4_en_priv *priv,
+			      struct mlx4_en_rx_alloc *frag)
 {
-	struct mlx4_en_rx_alloc *page_alloc;
-	int i;
-
-	for (i = 0; i < priv->num_frags; i++) {
-		const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
-
-		page_alloc = &ring->page_alloc[i];
-		en_dbg(DRV, priv, "Freeing allocator:%d count:%d\n",
-		       i, page_count(page_alloc->page));
-
-		dma_unmap_page(priv->ddev, page_alloc->dma,
-				page_alloc->page_size, frag_info->dma_dir);
-		while (page_alloc->page_offset + frag_info->frag_stride <
-		       page_alloc->page_size) {
-			put_page(page_alloc->page);
-			page_alloc->page_offset += frag_info->frag_stride;
-		}
-		page_alloc->page = NULL;
+	if (frag->page) {
+		dma_unmap_page(priv->ddev, frag->dma,
+			       PAGE_SIZE, priv->dma_dir);
+		__free_page(frag->page);
 	}
+	/* We need to clear all fields, otherwise a change of priv->log_rx_info
+	 * could lead to see garbage later in frag->page.
+	 */
+	memset(frag, 0, sizeof(*frag));
 }
 
-static void mlx4_en_init_rx_desc(struct mlx4_en_priv *priv,
+static void mlx4_en_init_rx_desc(const struct mlx4_en_priv *priv,
 				 struct mlx4_en_rx_ring *ring, int index)
 {
 	struct mlx4_en_rx_desc *rx_desc = ring->buf + ring->stride * index;
@@ -248,18 +137,23 @@ static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
 	struct mlx4_en_rx_desc *rx_desc = ring->buf + (index * ring->stride);
 	struct mlx4_en_rx_alloc *frags = ring->rx_info +
 					(index << priv->log_rx_info);
-
 	if (ring->page_cache.index > 0) {
-		frags[0] = ring->page_cache.buf[--ring->page_cache.index];
-		rx_desc->data[0].addr = cpu_to_be64(frags[0].dma +
-						    frags[0].page_offset);
+		/* XDP uses a single page per frame */
+		if (!frags->page) {
+			ring->page_cache.index--;
+			frags->page = ring->page_cache.buf[ring->page_cache.index].page;
+			frags->dma  = ring->page_cache.buf[ring->page_cache.index].dma;
+		}
+		frags->page_offset = XDP_PACKET_HEADROOM;
+		rx_desc->data[0].addr = cpu_to_be64(frags->dma +
+						    XDP_PACKET_HEADROOM);
 		return 0;
 	}
 
-	return mlx4_en_alloc_frags(priv, rx_desc, frags, ring->page_alloc, gfp);
+	return mlx4_en_alloc_frags(priv, ring, rx_desc, frags, gfp);
 }
 
-static inline bool mlx4_en_is_ring_empty(struct mlx4_en_rx_ring *ring)
+static bool mlx4_en_is_ring_empty(const struct mlx4_en_rx_ring *ring)
 {
 	return ring->prod == ring->cons;
 }
@@ -269,7 +163,8 @@ static inline void mlx4_en_update_rx_prod_db(struct mlx4_en_rx_ring *ring)
 	*ring->wqres.db.db = cpu_to_be32(ring->prod & 0xffff);
 }
 
-static void mlx4_en_free_rx_desc(struct mlx4_en_priv *priv,
+/* slow path */
+static void mlx4_en_free_rx_desc(const struct mlx4_en_priv *priv,
 				 struct mlx4_en_rx_ring *ring,
 				 int index)
 {
@@ -279,7 +174,7 @@ static void mlx4_en_free_rx_desc(struct mlx4_en_priv *priv,
 	frags = ring->rx_info + (index << priv->log_rx_info);
 	for (nr = 0; nr < priv->num_frags; nr++) {
 		en_dbg(DRV, priv, "Freeing fragment:%d\n", nr);
-		mlx4_en_free_frag(priv, frags, nr);
+		mlx4_en_free_frag(priv, frags + nr);
 	}
 }
 
@@ -335,12 +230,12 @@ static void mlx4_en_free_rx_buf(struct mlx4_en_priv *priv,
 	       ring->cons, ring->prod);
 
 	/* Unmap and free Rx buffers */
-	while (!mlx4_en_is_ring_empty(ring)) {
-		index = ring->cons & ring->size_mask;
+	for (index = 0; index < ring->size; index++) {
 		en_dbg(DRV, priv, "Processing descriptor:%d\n", index);
 		mlx4_en_free_rx_desc(priv, ring, index);
-		++ring->cons;
 	}
+	ring->cons = 0;
+	ring->prod = 0;
 }
 
 void mlx4_en_set_num_rx_rings(struct mlx4_en_dev *mdev)
@@ -392,9 +287,9 @@ int mlx4_en_create_rx_ring(struct mlx4_en_priv *priv,
 
 	tmp = size * roundup_pow_of_two(MLX4_EN_MAX_RX_FRAGS *
 					sizeof(struct mlx4_en_rx_alloc));
-	ring->rx_info = vmalloc_node(tmp, node);
+	ring->rx_info = vzalloc_node(tmp, node);
 	if (!ring->rx_info) {
-		ring->rx_info = vmalloc(tmp);
+		ring->rx_info = vzalloc(tmp);
 		if (!ring->rx_info) {
 			err = -ENOMEM;
 			goto err_ring;
@@ -464,16 +359,6 @@ int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv)
 		/* Initialize all descriptors */
 		for (i = 0; i < ring->size; i++)
 			mlx4_en_init_rx_desc(priv, ring, i);
-
-		/* Initialize page allocators */
-		err = mlx4_en_init_allocator(priv, ring);
-		if (err) {
-			en_err(priv, "Failed initializing ring allocator\n");
-			if (ring->stride <= TXBB_SIZE)
-				ring->buf -= TXBB_SIZE;
-			ring_ind--;
-			goto err_allocator;
-		}
 	}
 	err = mlx4_en_fill_rx_buffers(priv);
 	if (err)
@@ -493,11 +378,9 @@ int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv)
 		mlx4_en_free_rx_buf(priv, priv->rx_ring[ring_ind]);
 
 	ring_ind = priv->rx_ring_num - 1;
-err_allocator:
 	while (ring_ind >= 0) {
 		if (priv->rx_ring[ring_ind]->stride <= TXBB_SIZE)
 			priv->rx_ring[ring_ind]->buf -= TXBB_SIZE;
-		mlx4_en_destroy_allocator(priv, priv->rx_ring[ring_ind]);
 		ring_ind--;
 	}
 	return err;
@@ -537,7 +420,9 @@ bool mlx4_en_rx_recycle(struct mlx4_en_rx_ring *ring,
 	if (cache->index >= MLX4_EN_CACHE_SIZE)
 		return false;
 
-	cache->buf[cache->index++] = *frame;
+	cache->buf[cache->index].page = frame->page;
+	cache->buf[cache->index].dma = frame->dma;
+	cache->index++;
 	return true;
 }
 
@@ -567,136 +452,91 @@ void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
 	int i;
 
 	for (i = 0; i < ring->page_cache.index; i++) {
-		struct mlx4_en_rx_alloc *frame = &ring->page_cache.buf[i];
-
-		dma_unmap_page(priv->ddev, frame->dma, frame->page_size,
-			       priv->frag_info[0].dma_dir);
-		put_page(frame->page);
+		dma_unmap_page(priv->ddev, ring->page_cache.buf[i].dma,
+			       PAGE_SIZE, priv->dma_dir);
+		put_page(ring->page_cache.buf[i].page);
 	}
 	ring->page_cache.index = 0;
 	mlx4_en_free_rx_buf(priv, ring);
 	if (ring->stride <= TXBB_SIZE)
 		ring->buf -= TXBB_SIZE;
-	mlx4_en_destroy_allocator(priv, ring);
 }
 
 
 static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
-				    struct mlx4_en_rx_desc *rx_desc,
 				    struct mlx4_en_rx_alloc *frags,
 				    struct sk_buff *skb,
 				    int length)
 {
-	struct skb_frag_struct *skb_frags_rx = skb_shinfo(skb)->frags;
-	struct mlx4_en_frag_info *frag_info;
-	int nr;
+	const struct mlx4_en_frag_info *frag_info = priv->frag_info;
+	unsigned int truesize = 0;
+	int nr, frag_size;
+	struct page *page;
 	dma_addr_t dma;
+	bool release;
 
 	/* Collect used fragments while replacing them in the HW descriptors */
-	for (nr = 0; nr < priv->num_frags; nr++) {
-		frag_info = &priv->frag_info[nr];
-		if (length <= frag_info->frag_prefix_size)
-			break;
-		if (unlikely(!frags[nr].page))
+	for (nr = 0;; frags++) {
+		frag_size = min_t(int, length, frag_info->frag_size);
+
+		page = frags->page;
+		if (unlikely(!page))
 			goto fail;
 
-		dma = be64_to_cpu(rx_desc->data[nr].addr);
-		dma_sync_single_for_cpu(priv->ddev, dma, frag_info->frag_size,
-					DMA_FROM_DEVICE);
+		dma = frags->dma;
+		dma_sync_single_range_for_cpu(priv->ddev, dma, frags->page_offset,
+					      frag_size, priv->dma_dir);
+
+		__skb_fill_page_desc(skb, nr, page, frags->page_offset,
+				     frag_size);
+
+		truesize += frag_info->frag_stride;
+		if (frag_info->frag_stride == PAGE_SIZE / 2) {
+			frags->page_offset ^= PAGE_SIZE / 2;
+			release = page_count(page) != 1 ||
+				  page_is_pfmemalloc(page) ||
+				  page_to_nid(page) != numa_mem_id();
+		} else {
+			u32 sz_align = ALIGN(frag_size, SMP_CACHE_BYTES);
 
-		__skb_fill_page_desc(skb, nr, frags[nr].page,
-				     frags[nr].page_offset,
-				     frag_info->frag_size);
+			frags->page_offset += sz_align;
+			release = frags->page_offset + frag_info->frag_size > PAGE_SIZE;
+		}
+		if (release) {
+			dma_unmap_page(priv->ddev, dma, PAGE_SIZE, priv->dma_dir);
+			frags->page = NULL;
+		} else {
+			page_ref_inc(page);
+		}
 
-		skb->truesize += frag_info->frag_stride;
-		frags[nr].page = NULL;
+		nr++;
+		length -= frag_size;
+		if (!length)
+			break;
+		frag_info++;
 	}
-	/* Adjust size of last fragment to match actual length */
-	if (nr > 0)
-		skb_frag_size_set(&skb_frags_rx[nr - 1],
-			length - priv->frag_info[nr - 1].frag_prefix_size);
+	skb->truesize += truesize;
 	return nr;
 
 fail:
 	while (nr > 0) {
 		nr--;
-		__skb_frag_unref(&skb_frags_rx[nr]);
+		__skb_frag_unref(skb_shinfo(skb)->frags + nr);
 	}
 	return 0;
 }
 
-
-static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
-				      struct mlx4_en_rx_desc *rx_desc,
-				      struct mlx4_en_rx_alloc *frags,
-				      unsigned int length)
-{
-	struct sk_buff *skb;
-	void *va;
-	int used_frags;
-	dma_addr_t dma;
-
-	skb = netdev_alloc_skb(priv->dev, SMALL_PACKET_SIZE + NET_IP_ALIGN);
-	if (unlikely(!skb)) {
-		en_dbg(RX_ERR, priv, "Failed allocating skb\n");
-		return NULL;
-	}
-	skb_reserve(skb, NET_IP_ALIGN);
-	skb->len = length;
-
-	/* Get pointer to first fragment so we could copy the headers into the
-	 * (linear part of the) skb */
-	va = page_address(frags[0].page) + frags[0].page_offset;
-
-	if (length <= SMALL_PACKET_SIZE) {
-		/* We are copying all relevant data to the skb - temporarily
-		 * sync buffers for the copy */
-		dma = be64_to_cpu(rx_desc->data[0].addr);
-		dma_sync_single_for_cpu(priv->ddev, dma, length,
-					DMA_FROM_DEVICE);
-		skb_copy_to_linear_data(skb, va, length);
-		skb->tail += length;
-	} else {
-		unsigned int pull_len;
-
-		/* Move relevant fragments to skb */
-		used_frags = mlx4_en_complete_rx_desc(priv, rx_desc, frags,
-							skb, length);
-		if (unlikely(!used_frags)) {
-			kfree_skb(skb);
-			return NULL;
-		}
-		skb_shinfo(skb)->nr_frags = used_frags;
-
-		pull_len = eth_get_headlen(va, SMALL_PACKET_SIZE);
-		/* Copy headers into the skb linear buffer */
-		memcpy(skb->data, va, pull_len);
-		skb->tail += pull_len;
-
-		/* Skip headers in first fragment */
-		skb_shinfo(skb)->frags[0].page_offset += pull_len;
-
-		/* Adjust size of first fragment */
-		skb_frag_size_sub(&skb_shinfo(skb)->frags[0], pull_len);
-		skb->data_len = length - pull_len;
-	}
-	return skb;
-}
-
-static void validate_loopback(struct mlx4_en_priv *priv, struct sk_buff *skb)
+static void validate_loopback(struct mlx4_en_priv *priv, void *va)
 {
+	const unsigned char *data = va + ETH_HLEN;
 	int i;
-	int offset = ETH_HLEN;
 
-	for (i = 0; i < MLX4_LOOPBACK_TEST_PAYLOAD; i++, offset++) {
-		if (*(skb->data + offset) != (unsigned char) (i & 0xff))
-			goto out_loopback;
+	for (i = 0; i < MLX4_LOOPBACK_TEST_PAYLOAD; i++) {
+		if (data[i] != (unsigned char)i)
+			return;
 	}
 	/* Loopback found */
 	priv->loopback_ok = 1;
-
-out_loopback:
-	dev_kfree_skb_any(skb);
 }
 
 static bool mlx4_en_refill_rx_buffers(struct mlx4_en_priv *priv,
@@ -801,7 +641,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 	struct mlx4_cqe *cqe;
 	struct mlx4_en_rx_ring *ring = priv->rx_ring[cq->ring];
 	struct mlx4_en_rx_alloc *frags;
-	struct mlx4_en_rx_desc *rx_desc;
 	struct bpf_prog *xdp_prog;
 	int doorbell_pending;
 	struct sk_buff *skb;
@@ -834,10 +673,10 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 	/* Process all completed CQEs */
 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
 		    cq->mcq.cons_index & cq->size)) {
+		void *va;
 
 		frags = ring->rx_info + (index << priv->log_rx_info);
-		rx_desc = ring->buf + (index << ring->log_stride);
-
+		va = page_address(frags[0].page) + frags[0].page_offset;
 		/*
 		 * make sure we read the CQE after we read the ownership bit
 		 */
@@ -860,16 +699,14 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 		 * and not performing the selftest or flb disabled
 		 */
 		if (priv->flags & MLX4_EN_FLAG_RX_FILTER_NEEDED) {
-			struct ethhdr *ethh;
+			const struct ethhdr *ethh = va;
 			dma_addr_t dma;
 			/* Get pointer to first fragment since we haven't
 			 * skb yet and cast it to ethhdr struct
 			 */
-			dma = be64_to_cpu(rx_desc->data[0].addr);
+			dma = frags[0].dma + frags[0].page_offset;
 			dma_sync_single_for_cpu(priv->ddev, dma, sizeof(*ethh),
 						DMA_FROM_DEVICE);
-			ethh = (struct ethhdr *)(page_address(frags[0].page) +
-						 frags[0].page_offset);
 
 			if (is_multicast_ether_addr(ethh->h_dest)) {
 				struct mlx4_mac_entry *entry;
@@ -887,13 +724,16 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			}
 		}
 
+		if (unlikely(priv->validate_loopback)) {
+			validate_loopback(priv, va);
+			goto next;
+		}
+
 		/*
 		 * Packet is OK - process it.
 		 */
 		length = be32_to_cpu(cqe->byte_cnt);
 		length -= ring->fcs_del;
-		l2_tunnel = (dev->hw_enc_features & NETIF_F_RXCSUM) &&
-			(cqe->vlan_my_qpn & cpu_to_be32(MLX4_CQE_L2_TUNNEL));
 
 		/* A bpf program gets first chance to drop the packet. It may
 		 * read bytes but not past the end of the frag.
@@ -904,13 +744,13 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			void *orig_data;
 			u32 act;
 
-			dma = be64_to_cpu(rx_desc->data[0].addr);
+			dma = frags[0].dma + frags[0].page_offset;
 			dma_sync_single_for_cpu(priv->ddev, dma,
 						priv->frag_info[0].frag_size,
 						DMA_FROM_DEVICE);
 
-			xdp.data_hard_start = page_address(frags[0].page);
-			xdp.data = xdp.data_hard_start + frags[0].page_offset;
+			xdp.data_hard_start = va - frags[0].page_offset;
+			xdp.data = va;
 			xdp.data_end = xdp.data + length;
 			orig_data = xdp.data;
 
@@ -920,6 +760,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 				length = xdp.data_end - xdp.data;
 				frags[0].page_offset = xdp.data -
 					xdp.data_hard_start;
+				va = xdp.data;
 			}
 
 			switch (act) {
@@ -928,8 +769,10 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			case XDP_TX:
 				if (likely(!mlx4_en_xmit_frame(ring, frags, dev,
 							length, cq->ring,
-							&doorbell_pending)))
-					goto consumed;
+							&doorbell_pending))) {
+					frags[0].page = NULL;
+					goto next;
+				}
 				trace_xdp_exception(dev, xdp_prog, act);
 				goto xdp_drop_no_cnt; /* Drop on xmit failure */
 			default:
@@ -939,8 +782,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			case XDP_DROP:
 				ring->xdp_drop++;
 xdp_drop_no_cnt:
-				if (likely(mlx4_en_rx_recycle(ring, frags)))
-					goto consumed;
 				goto next;
 			}
 		}
@@ -948,129 +789,51 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 		ring->bytes += length;
 		ring->packets++;
 
+		skb = napi_get_frags(&cq->napi);
+		if (!skb)
+			goto next;
+
+		if (unlikely(ring->hwtstamp_rx_filter == HWTSTAMP_FILTER_ALL)) {
+			timestamp = mlx4_en_get_cqe_ts(cqe);
+			mlx4_en_fill_hwtstamps(mdev, skb_hwtstamps(skb),
+					       timestamp);
+		}
+		skb_record_rx_queue(skb, cq->ring);
+
 		if (likely(dev->features & NETIF_F_RXCSUM)) {
 			if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_TCP |
 						      MLX4_CQE_STATUS_UDP)) {
 				if ((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPOK)) &&
 				    cqe->checksum == cpu_to_be16(0xffff)) {
 					ip_summed = CHECKSUM_UNNECESSARY;
+					l2_tunnel = (dev->hw_enc_features & NETIF_F_RXCSUM) &&
+						(cqe->vlan_my_qpn & cpu_to_be32(MLX4_CQE_L2_TUNNEL));
+					if (l2_tunnel)
+						skb->csum_level = 1;
 					ring->csum_ok++;
 				} else {
-					ip_summed = CHECKSUM_NONE;
-					ring->csum_none++;
+					goto csum_none;
 				}
 			} else {
 				if (priv->flags & MLX4_EN_FLAG_RX_CSUM_NON_TCP_UDP &&
 				    (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV4 |
 							       MLX4_CQE_STATUS_IPV6))) {
+					if (check_csum(cqe, skb, va, dev->features)) {
+						goto csum_none;
+					} else {
 						ip_summed = CHECKSUM_COMPLETE;
 						ring->csum_complete++;
-				} else {
-					ip_summed = CHECKSUM_NONE;
-					ring->csum_none++;
-				}
 					}
 				} else {
-			ip_summed = CHECKSUM_NONE;
-			ring->csum_none++;
-		}
-
-		/* This packet is eligible for GRO if it is:
-		 * - DIX Ethernet (type interpretation)
-		 * - TCP/IP (v4)
-		 * - without IP options
-		 * - not an IP fragment
-		 */
-		if (dev->features & NETIF_F_GRO) {
-			struct sk_buff *gro_skb = napi_get_frags(&cq->napi);
-			if (!gro_skb)
-				goto next;
-
-			nr = mlx4_en_complete_rx_desc(priv,
-				rx_desc, frags, gro_skb,
-				length);
-			if (!nr)
-				goto next;
-
-			if (ip_summed == CHECKSUM_COMPLETE) {
-				void *va = skb_frag_address(skb_shinfo(gro_skb)->frags);
-				if (check_csum(cqe, gro_skb, va,
-					       dev->features)) {
-					ip_summed = CHECKSUM_NONE;
-					ring->csum_none++;
-					ring->csum_complete--;
-				}
-			}
-
-			skb_shinfo(gro_skb)->nr_frags = nr;
-			gro_skb->len = length;
-			gro_skb->data_len = length;
-			gro_skb->ip_summed = ip_summed;
-
-			if (l2_tunnel && ip_summed == CHECKSUM_UNNECESSARY)
-				gro_skb->csum_level = 1;
-
-			if ((cqe->vlan_my_qpn &
-			    cpu_to_be32(MLX4_CQE_CVLAN_PRESENT_MASK)) &&
-			    (dev->features & NETIF_F_HW_VLAN_CTAG_RX)) {
-				u16 vid = be16_to_cpu(cqe->sl_vid);
-
-				__vlan_hwaccel_put_tag(gro_skb, htons(ETH_P_8021Q), vid);
-			} else if ((be32_to_cpu(cqe->vlan_my_qpn) &
-				  MLX4_CQE_SVLAN_PRESENT_MASK) &&
-				 (dev->features & NETIF_F_HW_VLAN_STAG_RX)) {
-				__vlan_hwaccel_put_tag(gro_skb,
-						       htons(ETH_P_8021AD),
-						       be16_to_cpu(cqe->sl_vid));
+					goto csum_none;
 				}
-
-			if (dev->features & NETIF_F_RXHASH)
-				skb_set_hash(gro_skb,
-					     be32_to_cpu(cqe->immed_rss_invalid),
-					     (ip_summed == CHECKSUM_UNNECESSARY) ?
-						PKT_HASH_TYPE_L4 :
-						PKT_HASH_TYPE_L3);
-
-			skb_record_rx_queue(gro_skb, cq->ring);
-
-			if (ring->hwtstamp_rx_filter == HWTSTAMP_FILTER_ALL) {
-				timestamp = mlx4_en_get_cqe_ts(cqe);
-				mlx4_en_fill_hwtstamps(mdev,
-						       skb_hwtstamps(gro_skb),
-						       timestamp);
 			}
-
-			napi_gro_frags(&cq->napi);
-			goto next;
-		}
-
-		/* GRO not possible, complete processing here */
-		skb = mlx4_en_rx_skb(priv, rx_desc, frags, length);
-		if (unlikely(!skb)) {
-			ring->dropped++;
-			goto next;
-		}
-
-		if (unlikely(priv->validate_loopback)) {
-			validate_loopback(priv, skb);
-			goto next;
-		}
-
-		if (ip_summed == CHECKSUM_COMPLETE) {
-			if (check_csum(cqe, skb, skb->data, dev->features)) {
+		} else {
+csum_none:
 			ip_summed = CHECKSUM_NONE;
-				ring->csum_complete--;
 			ring->csum_none++;
 		}
-		}
-
 		skb->ip_summed = ip_summed;
-		skb->protocol = eth_type_trans(skb, dev);
-		skb_record_rx_queue(skb, cq->ring);
-
-		if (l2_tunnel && ip_summed == CHECKSUM_UNNECESSARY)
-			skb->csum_level = 1;
-
 		if (dev->features & NETIF_F_RXHASH)
 			skb_set_hash(skb,
 				     be32_to_cpu(cqe->immed_rss_invalid),
@@ -1078,36 +841,36 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 					PKT_HASH_TYPE_L4 :
 					PKT_HASH_TYPE_L3);
 
-		if ((be32_to_cpu(cqe->vlan_my_qpn) &
-		    MLX4_CQE_CVLAN_PRESENT_MASK) &&
+
+		if ((cqe->vlan_my_qpn &
+		     cpu_to_be32(MLX4_CQE_CVLAN_PRESENT_MASK)) &&
 		    (dev->features & NETIF_F_HW_VLAN_CTAG_RX))
-			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), be16_to_cpu(cqe->sl_vid));
-		else if ((be32_to_cpu(cqe->vlan_my_qpn) &
-			  MLX4_CQE_SVLAN_PRESENT_MASK) &&
+			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
+					       be16_to_cpu(cqe->sl_vid));
+		else if ((cqe->vlan_my_qpn &
+			  cpu_to_be32(MLX4_CQE_SVLAN_PRESENT_MASK)) &&
 			 (dev->features & NETIF_F_HW_VLAN_STAG_RX))
 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021AD),
 					       be16_to_cpu(cqe->sl_vid));
 
-		if (ring->hwtstamp_rx_filter == HWTSTAMP_FILTER_ALL) {
-			timestamp = mlx4_en_get_cqe_ts(cqe);
-			mlx4_en_fill_hwtstamps(mdev, skb_hwtstamps(skb),
-					       timestamp);
+		nr = mlx4_en_complete_rx_desc(priv, frags, skb, length);
+		if (likely(nr)) {
+			skb_shinfo(skb)->nr_frags = nr;
+			skb->len = length;
+			skb->data_len = length;
+			napi_gro_frags(&cq->napi);
+		} else {
+			skb->vlan_tci = 0;
+			skb_clear_hash(skb);
 		}
-
-		napi_gro_receive(&cq->napi, skb);
 next:
-		for (nr = 0; nr < priv->num_frags; nr++)
-			mlx4_en_free_frag(priv, frags, nr);
-
-consumed:
 		++cq->mcq.cons_index;
 		index = (cq->mcq.cons_index) & ring->size_mask;
 		cqe = mlx4_en_get_cqe(cq->buf, index, priv->cqe_size) + factor;
 		if (++polled == budget)
-			goto out;
+			break;
 	}
 
-out:
 	rcu_read_unlock();
 
 	if (polled) {
@@ -1178,13 +941,6 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
 	return done;
 }
 
-static const int frag_sizes[] = {
-	FRAG_SZ0,
-	FRAG_SZ1,
-	FRAG_SZ2,
-	FRAG_SZ3
-};
-
 void mlx4_en_calc_rx_buf(struct net_device *dev)
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
@@ -1195,33 +951,43 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 	 * This only works when num_frags == 1.
 	 */
 	if (priv->tx_ring_num[TX_XDP]) {
-		priv->frag_info[0].order = 0;
 		priv->frag_info[0].frag_size = eff_mtu;
-		priv->frag_info[0].frag_prefix_size = 0;
 		/* This will gain efficient xdp frame recycling at the
 		 * expense of more costly truesize accounting
 		 */
 		priv->frag_info[0].frag_stride = PAGE_SIZE;
-		priv->frag_info[0].dma_dir = PCI_DMA_BIDIRECTIONAL;
-		priv->frag_info[0].rx_headroom = XDP_PACKET_HEADROOM;
+		priv->dma_dir = PCI_DMA_BIDIRECTIONAL;
+		priv->rx_headroom = XDP_PACKET_HEADROOM;
 		i = 1;
 	} else {
-		int buf_size = 0;
+		int frag_size_max = 2048, buf_size = 0;
+
+		/* should not happen, right ? */
+		if (eff_mtu > PAGE_SIZE + (MLX4_EN_MAX_RX_FRAGS - 1) * 2048)
+			frag_size_max = PAGE_SIZE;
 
 		while (buf_size < eff_mtu) {
-			priv->frag_info[i].order = MLX4_EN_ALLOC_PREFER_ORDER;
-			priv->frag_info[i].frag_size =
-				(eff_mtu > buf_size + frag_sizes[i]) ?
-					frag_sizes[i] : eff_mtu - buf_size;
-			priv->frag_info[i].frag_prefix_size = buf_size;
-			priv->frag_info[i].frag_stride =
-				ALIGN(priv->frag_info[i].frag_size,
-				      SMP_CACHE_BYTES);
-			priv->frag_info[i].dma_dir = PCI_DMA_FROMDEVICE;
-			priv->frag_info[i].rx_headroom = 0;
-			buf_size += priv->frag_info[i].frag_size;
+			int frag_stride, frag_size = eff_mtu - buf_size;
+			int pad, nb;
+
+			if (i < MLX4_EN_MAX_RX_FRAGS - 1)
+				frag_size = min(frag_size, frag_size_max);
+
+			priv->frag_info[i].frag_size = frag_size;
+			frag_stride = ALIGN(frag_size, SMP_CACHE_BYTES);
+			/* We can only pack 2 1536-bytes frames in on 4K page
+			 * Therefore, each frame would consume more bytes (truesize)
+			 */
+			nb = PAGE_SIZE / frag_stride;
+			pad = (PAGE_SIZE - nb * frag_stride) / nb;
+			pad &= ~(SMP_CACHE_BYTES - 1);
+			priv->frag_info[i].frag_stride = frag_stride + pad;
+
+			buf_size += frag_size;
 			i++;
 		}
+		priv->dma_dir = PCI_DMA_FROMDEVICE;
+		priv->rx_headroom = 0;
 	}
 
 	priv->num_frags = i;
@@ -1232,10 +998,9 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 	       eff_mtu, priv->num_frags);
 	for (i = 0; i < priv->num_frags; i++) {
 		en_err(priv,
-		       "  frag:%d - size:%d prefix:%d stride:%d\n",
+		       "  frag:%d - size:%d stride:%d\n",
 		       i,
 		       priv->frag_info[i].frag_size,
-		       priv->frag_info[i].frag_prefix_size,
 		       priv->frag_info[i].frag_stride);
 	}
 }

drivers/net/ethernet/mellanox/mlx4/en_selftest.c

@@ -81,14 +81,11 @@ static int mlx4_en_test_loopback(struct mlx4_en_priv *priv)
 {
 	u32 loopback_ok = 0;
 	int i;
-	bool gro_enabled;
 
         priv->loopback_ok = 0;
 	priv->validate_loopback = 1;
-	gro_enabled = priv->dev->features & NETIF_F_GRO;
 
 	mlx4_en_update_loopback_state(priv->dev, priv->dev->features);
-	priv->dev->features &= ~NETIF_F_GRO;
 
 	/* xmit */
 	if (mlx4_en_test_loopback_xmit(priv)) {
@@ -111,9 +108,6 @@ static int mlx4_en_test_loopback(struct mlx4_en_priv *priv)
 
 	priv->validate_loopback = 0;
 
-	if (gro_enabled)
-		priv->dev->features |= NETIF_F_GRO;
-
 	mlx4_en_update_loopback_state(priv->dev, priv->dev->features);
 	return !loopback_ok;
 }

drivers/net/ethernet/mellanox/mlx4/en_tx.c

@@ -354,13 +354,11 @@ u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
 	struct mlx4_en_rx_alloc frame = {
 		.page = tx_info->page,
 		.dma = tx_info->map0_dma,
-		.page_offset = XDP_PACKET_HEADROOM,
-		.page_size = PAGE_SIZE,
 	};
 
 	if (!mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
 		dma_unmap_page(priv->ddev, tx_info->map0_dma,
-			       PAGE_SIZE, priv->frag_info[0].dma_dir);
+			       PAGE_SIZE, priv->dma_dir);
 		put_page(tx_info->page);
 	}
 

drivers/net/ethernet/mellanox/mlx4/mlx4_en.h

@@ -102,17 +102,6 @@
 /* Use the maximum between 16384 and a single page */
 #define MLX4_EN_ALLOC_SIZE	PAGE_ALIGN(16384)
 
-#define MLX4_EN_ALLOC_PREFER_ORDER min_t(int, get_order(32768),		\
-					 PAGE_ALLOC_COSTLY_ORDER)
-
-/* Receive fragment sizes; we use at most 3 fragments (for 9600 byte MTU
- * and 4K allocations) */
-enum {
-	FRAG_SZ0 = 1536 - NET_IP_ALIGN,
-	FRAG_SZ1 = 4096,
-	FRAG_SZ2 = 4096,
-	FRAG_SZ3 = MLX4_EN_ALLOC_SIZE
-};
 #define MLX4_EN_MAX_RX_FRAGS	4
 
 /* Maximum ring sizes */
@@ -264,13 +253,16 @@ struct mlx4_en_rx_alloc {
 	struct page	*page;
 	dma_addr_t	dma;
 	u32		page_offset;
-	u32		page_size;
 };
 
 #define MLX4_EN_CACHE_SIZE (2 * NAPI_POLL_WEIGHT)
+
 struct mlx4_en_page_cache {
 	u32 index;
-	struct mlx4_en_rx_alloc buf[MLX4_EN_CACHE_SIZE];
+	struct {
+		struct page	*page;
+		dma_addr_t	dma;
+	} buf[MLX4_EN_CACHE_SIZE];
 };
 
 struct mlx4_en_priv;
@@ -335,7 +327,6 @@ struct mlx4_en_rx_desc {
 
 struct mlx4_en_rx_ring {
 	struct mlx4_hwq_resources wqres;
-	struct mlx4_en_rx_alloc page_alloc[MLX4_EN_MAX_RX_FRAGS];
 	u32 size ;	/* number of Rx descs*/
 	u32 actual_size;
 	u32 size_mask;
@@ -355,6 +346,7 @@ struct mlx4_en_rx_ring {
 	unsigned long csum_ok;
 	unsigned long csum_none;
 	unsigned long csum_complete;
+	unsigned long rx_alloc_pages;
 	unsigned long xdp_drop;
 	unsigned long xdp_tx;
 	unsigned long xdp_tx_full;
@@ -472,11 +464,7 @@ struct mlx4_en_mc_list {
 
 struct mlx4_en_frag_info {
 	u16 frag_size;
-	u16 frag_prefix_size;
 	u32 frag_stride;
-	enum dma_data_direction dma_dir;
-	u16 order;
-	u16 rx_headroom;
 };
 
 #ifdef CONFIG_MLX4_EN_DCB
@@ -584,8 +572,10 @@ struct mlx4_en_priv {
 	u32 rx_ring_num;
 	u32 rx_skb_size;
 	struct mlx4_en_frag_info frag_info[MLX4_EN_MAX_RX_FRAGS];
-	u16 num_frags;
-	u16 log_rx_info;
+	u8 num_frags;
+	u8 log_rx_info;
+	u8 dma_dir;
+	u16 rx_headroom;
 
 	struct mlx4_en_tx_ring **tx_ring[MLX4_EN_NUM_TX_TYPES];
 	struct mlx4_en_rx_ring *rx_ring[MAX_RX_RINGS];

drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h

@@ -37,7 +37,7 @@ struct mlx4_en_port_stats {
 	unsigned long queue_stopped;
 	unsigned long wake_queue;
 	unsigned long tx_timeout;
-	unsigned long rx_alloc_failed;
+	unsigned long rx_alloc_pages;
 	unsigned long rx_chksum_good;
 	unsigned long rx_chksum_none;
 	unsigned long rx_chksum_complete;