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         /* We run in BH context */
  36         spin_lock(&cell->napi_skbs.lock);
  37
  38         __skb_queue_tail(&cell->napi_skbs, skb);
  39         if (skb_queue_len(&cell->napi_skbs) == 1)
  40                 napi_schedule(&cell->napi);
  41
  42         spin_unlock(&cell->napi_skbs.lock);
  43 }
  44
  45 /* called unser BH context */
  46 static inline int gro_cell_poll(struct napi_struct *napi, int budget)
  47 {
  48         struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
  49         struct sk_buff *skb;
  50         int work_done = 0;
  51
  52         spin_lock(&cell->napi_skbs.lock);
  53         while (work_done < budget) {
  54                 skb = __skb_dequeue(&cell->napi_skbs);
  55                 if (!skb)
  56                         break;
  57                 spin_unlock(&cell->napi_skbs.lock);
  58                 napi_gro_receive(napi, skb);
  59                 work_done++;
  60                 spin_lock(&cell->napi_skbs.lock);
  61         }
  62
  63         if (work_done < budget)
  64                 napi_complete(napi);
  65         spin_unlock(&cell->napi_skbs.lock);
  66         return work_done;
  67 }
  68
  69 static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
  70 {
  71         int i;
  72
  73         gcells->cells = alloc_percpu(struct gro_cell);
  74         if (!gcells->cells)
  75                 return -ENOMEM;
  76
  77         for_each_possible_cpu(i) {
  78                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  79
  80                 skb_queue_head_init(&cell->napi_skbs);
  81                 netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
  82                 napi_enable(&cell->napi);
  83         }
  84         return 0;
  85 }
  86
  87 static inline void gro_cells_destroy(struct gro_cells *gcells)
  88 {
  89         int i;
  90
  91         if (!gcells->cells)
  92                 return;
  93         for_each_possible_cpu(i) {
  94                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  95                 netif_napi_del(&cell->napi);
  96                 skb_queue_purge(&cell->napi_skbs);
  97         }
  98         free_percpu(gcells->cells);
  99         gcells->cells = NULL;
 100 }
 101
 102 #endif