Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / include / net / gro_cells.h

diff --git a/kernel/include/net/gro_cells.h b/kernel/include/net/gro_cells.h
new file mode 100644 (file)
index 0000000..0f712c0
--- /dev/null
+++ b/kernel/include/net/gro_cells.h
@@ -0,0 +1,102 @@
+#ifndef _NET_GRO_CELLS_H
+#define _NET_GRO_CELLS_H
+
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+
+struct gro_cell {
+       struct sk_buff_head     napi_skbs;
+       struct napi_struct      napi;
+};
+
+struct gro_cells {
+       struct gro_cell __percpu        *cells;
+};
+
+static inline void gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
+{
+       struct gro_cell *cell;
+       struct net_device *dev = skb->dev;
+
+       if (!gcells->cells || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
+               netif_rx(skb);
+               return;
+       }
+
+       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;
+       }
+
+       /* We run in BH context */
+       spin_lock(&cell->napi_skbs.lock);
+
+       __skb_queue_tail(&cell->napi_skbs, skb);
+       if (skb_queue_len(&cell->napi_skbs) == 1)
+               napi_schedule(&cell->napi);
+
+       spin_unlock(&cell->napi_skbs.lock);
+}
+
+/* called unser BH context */
+static inline 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;
+
+       spin_lock(&cell->napi_skbs.lock);
+       while (work_done < budget) {
+               skb = __skb_dequeue(&cell->napi_skbs);
+               if (!skb)
+                       break;
+               spin_unlock(&cell->napi_skbs.lock);
+               napi_gro_receive(napi, skb);
+               work_done++;
+               spin_lock(&cell->napi_skbs.lock);
+       }
+
+       if (work_done < budget)
+               napi_complete(napi);
+       spin_unlock(&cell->napi_skbs.lock);
+       return work_done;
+}
+
+static inline 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);
+               netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
+               napi_enable(&cell->napi);
+       }
+       return 0;
+}
+
+static inline 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;
+}
+
+#endif