kernel/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         if (!gcells->cells || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
  23                 netif_rx(skb);
  24                 return;
  25         }
  26
  27         cell = this_cpu_ptr(gcells->cells);
  28
  29         if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
  30                 atomic_long_inc(&dev->rx_dropped);
  31                 kfree_skb(skb);
  32                 return;
  33         }
  34
  35         __skb_queue_tail(&cell->napi_skbs, skb);
  36         if (skb_queue_len(&cell->napi_skbs) == 1)
  37                 napi_schedule(&cell->napi);
  38 }
  39
  40 /* called under BH context */
  41 static inline int gro_cell_poll(struct napi_struct *napi, int budget)
  42 {
  43         struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
  44         struct sk_buff *skb;
  45         int work_done = 0;
  46
  47         while (work_done < budget) {
  48                 skb = __skb_dequeue(&cell->napi_skbs);
  49                 if (!skb)
  50                         break;
  51                 napi_gro_receive(napi, skb);
  52                 work_done++;
  53         }
  54
  55         if (work_done < budget)
  56                 napi_complete_done(napi, work_done);
  57         return work_done;
  58 }
  59
  60 static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
  61 {
  62         int i;
  63
  64         gcells->cells = alloc_percpu(struct gro_cell);
  65         if (!gcells->cells)
  66                 return -ENOMEM;
  67
  68         for_each_possible_cpu(i) {
  69                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  70
  71                 __skb_queue_head_init(&cell->napi_skbs);
  72                 netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
  73                 napi_enable(&cell->napi);
  74         }
  75         return 0;
  76 }
  77
  78 static inline void gro_cells_destroy(struct gro_cells *gcells)
  79 {
  80         int i;
  81
  82         if (!gcells->cells)
  83                 return;
  84         for_each_possible_cpu(i) {
  85                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  86
  87                 netif_napi_del(&cell->napi);
  88                 __skb_queue_purge(&cell->napi_skbs);
  89         }
  90         free_percpu(gcells->cells);
  91         gcells->cells = NULL;
  92 }
  93
  94 #endif