net/core/gro_cells.c

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