include/net/gro_cells.h

   1 #ifndef _NET_GRO_CELLS_H
   2 #define _NET_GRO_CELLS_H
   3
   4 #include <linux/skbuff.h>
   5 #include <linux/slab.h>
   6 #include <linux/netdevice.h>
   7
   8 struct gro_cell {
   9         struct sk_buff_head     napi_skbs;
  10         struct napi_struct      napi;
  11 };
  12
  13 struct gro_cells {
  14         struct gro_cell __percpu        *cells;
  15 };
  16
  17 static inline void gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
  18 {
  19         struct gro_cell *cell;
  20         struct net_device *dev = skb->dev;
  21
  22         rcu_read_lock();
  23         if (unlikely(!(dev->flags & IFF_UP)))
  24                 goto drop;
  25
  26         if (!gcells->cells || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
  27                 netif_rx(skb);
  28                 goto unlock;
  29         }
  30
  31         cell = this_cpu_ptr(gcells->cells);
  32
  33         if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
  34 drop:
  35                 atomic_long_inc(&dev->rx_dropped);
  36                 kfree_skb(skb);
  37                 goto unlock;
  38         }
  39
  40         __skb_queue_tail(&cell->napi_skbs, skb);
  41         if (skb_queue_len(&cell->napi_skbs) == 1)
  42                 napi_schedule(&cell->napi);
  43
  44 unlock:
  45         rcu_read_unlock();
  46 }
  47
  48 /* called under BH context */
  49 static inline int gro_cell_poll(struct napi_struct *napi, int budget)
  50 {
  51         struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
  52         struct sk_buff *skb;
  53         int work_done = 0;
  54
  55         while (work_done < budget) {
  56                 skb = __skb_dequeue(&cell->napi_skbs);
  57                 if (!skb)
  58                         break;
  59                 napi_gro_receive(napi, skb);
  60                 work_done++;
  61         }
  62
  63         if (work_done < budget)
  64                 napi_complete_done(napi, work_done);
  65         return work_done;
  66 }
  67
  68 static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
  69 {
  70         int i;
  71
  72         gcells->cells = alloc_percpu(struct gro_cell);
  73         if (!gcells->cells)
  74                 return -ENOMEM;
  75
  76         for_each_possible_cpu(i) {
  77                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  78
  79                 __skb_queue_head_init(&cell->napi_skbs);
  80                 netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
  81                 napi_enable(&cell->napi);
  82         }
  83         return 0;
  84 }
  85
  86 static inline void gro_cells_destroy(struct gro_cells *gcells)
  87 {
  88         int i;
  89
  90         if (!gcells->cells)
  91                 return;
  92         for_each_possible_cpu(i) {
  93                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  94
  95                 napi_disable(&cell->napi);
  96                 netif_napi_del(&cell->napi);
  97                 __skb_queue_purge(&cell->napi_skbs);
  98         }
  99         free_percpu(gcells->cells);
 100         gcells->cells = NULL;
 101 }
 102
 103 #endif