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 int 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                 return netif_rx(skb);
  24
  25         cell = this_cpu_ptr(gcells->cells);
  26
  27         if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
  28                 atomic_long_inc(&dev->rx_dropped);
  29                 kfree_skb(skb);
  30                 return NET_RX_DROP;
  31         }
  32
  33         __skb_queue_tail(&cell->napi_skbs, skb);
  34         if (skb_queue_len(&cell->napi_skbs) == 1)
  35                 napi_schedule(&cell->napi);
  36         return NET_RX_SUCCESS;
  37 }
  38
  39 /* called under BH context */
  40 static inline int gro_cell_poll(struct napi_struct *napi, int budget)
  41 {
  42         struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
  43         struct sk_buff *skb;
  44         int work_done = 0;
  45
  46         while (work_done < budget) {
  47                 skb = __skb_dequeue(&cell->napi_skbs);
  48                 if (!skb)
  49                         break;
  50                 napi_gro_receive(napi, skb);
  51                 work_done++;
  52         }
  53
  54         if (work_done < budget)
  55                 napi_complete_done(napi, work_done);
  56         return work_done;
  57 }
  58
  59 static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
  60 {
  61         int i;
  62
  63         gcells->cells = alloc_percpu(struct gro_cell);
  64         if (!gcells->cells)
  65                 return -ENOMEM;
  66
  67         for_each_possible_cpu(i) {
  68                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  69
  70                 __skb_queue_head_init(&cell->napi_skbs);
  71
  72                 set_bit(NAPI_STATE_NO_BUSY_POLL, &cell->napi.state);
  73
  74                 netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
  75                 napi_enable(&cell->napi);
  76         }
  77         return 0;
  78 }
  79
  80 static inline void gro_cells_destroy(struct gro_cells *gcells)
  81 {
  82         int i;
  83
  84         if (!gcells->cells)
  85                 return;
  86         for_each_possible_cpu(i) {
  87                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  88
  89                 netif_napi_del(&cell->napi);
  90                 __skb_queue_purge(&cell->napi_skbs);
  91         }
  92         free_percpu(gcells->cells);
  93         gcells->cells = NULL;
  94 }
  95
  96 #endif