gro_cells: move to net/core/gro_cells.c

We have many gro cells users, so lets move the code to avoid
duplication.

This creates a CONFIG_GRO_CELLS option.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 93 insertions, 0 deletions

diff --git a/net/core/Makefile b/net/core/Makefile
index f6761b6e3b29..79f9479e9658 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -28,3 +28,4 @@ obj-$(CONFIG_LWTUNNEL_BPF) += lwt_bpf.o
 obj-$(CONFIG_DST_CACHE) += dst_cache.o
 obj-$(CONFIG_HWBM) += hwbm.o
 obj-$(CONFIG_NET_DEVLINK) += devlink.o
+obj-$(CONFIG_GRO_CELLS) += gro_cells.o
diff --git a/net/core/gro_cells.c b/net/core/gro_cells.c
new file mode 100644
index 000000000000..c98bbfbd26b8
--- /dev/null
+++ b/net/core/gro_cells.c
@@ -0,0 +1,92 @@
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <net/gro_cells.h>
+
+struct gro_cell {
+	struct sk_buff_head	napi_skbs;
+	struct napi_struct	napi;
+};
+
+int gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	struct gro_cell *cell;
+
+	if (!gcells->cells || skb_cloned(skb) || !(dev->features & NETIF_F_GRO))
+		return netif_rx(skb);
+
+	cell = this_cpu_ptr(gcells->cells);
+
+	if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
+		atomic_long_inc(&dev->rx_dropped);
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
+	__skb_queue_tail(&cell->napi_skbs, skb);
+	if (skb_queue_len(&cell->napi_skbs) == 1)
+		napi_schedule(&cell->napi);
+	return NET_RX_SUCCESS;
+}
+EXPORT_SYMBOL(gro_cells_receive);
+
+/* called under BH context */
+static int gro_cell_poll(struct napi_struct *napi, int budget)
+{
+	struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
+	struct sk_buff *skb;
+	int work_done = 0;
+
+	while (work_done < budget) {
+		skb = __skb_dequeue(&cell->napi_skbs);
+		if (!skb)
+			break;
+		napi_gro_receive(napi, skb);
+		work_done++;
+	}
+
+	if (work_done < budget)
+		napi_complete_done(napi, work_done);
+	return work_done;
+}
+
+int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
+{
+	int i;
+
+	gcells->cells = alloc_percpu(struct gro_cell);
+	if (!gcells->cells)
+		return -ENOMEM;
+
+	for_each_possible_cpu(i) {
+		struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
+
+		__skb_queue_head_init(&cell->napi_skbs);
+
+		set_bit(NAPI_STATE_NO_BUSY_POLL, &cell->napi.state);
+
+		netif_napi_add(dev, &cell->napi, gro_cell_poll,
+			       NAPI_POLL_WEIGHT);
+		napi_enable(&cell->napi);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(gro_cells_init);
+
+void gro_cells_destroy(struct gro_cells *gcells)
+{
+	int i;
+
+	if (!gcells->cells)
+		return;
+	for_each_possible_cpu(i) {
+		struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
+
+		netif_napi_del(&cell->napi);
+		__skb_queue_purge(&cell->napi_skbs);
+	}
+	free_percpu(gcells->cells);
+	gcells->cells = NULL;
+}
+EXPORT_SYMBOL(gro_cells_destroy);