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         int res;
  22
  23         rcu_read_lock();
  24         if (unlikely(!(dev->flags & IFF_UP)))
  25                 goto drop;
  26
  27         if (!gcells->cells || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
  28                 res = netif_rx(skb);
  29                 goto unlock;
  30         }
  31
  32         cell = this_cpu_ptr(gcells->cells);
  33
  34         if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
  35 drop:
  36                 atomic_long_inc(&dev->rx_dropped);
  37                 kfree_skb(skb);
  38                 res = NET_RX_DROP;
  39                 goto unlock;
  40         }
  41
  42         __skb_queue_tail(&cell->napi_skbs, skb);
  43         if (skb_queue_len(&cell->napi_skbs) == 1)
  44                 napi_schedule(&cell->napi);
  45
  46         res = NET_RX_SUCCESS;
  47
  48 unlock:
  49         rcu_read_unlock();
  50         return res;
  51 }
  52
  53 /* called under BH context */
  54 static inline int gro_cell_poll(struct napi_struct *napi, int budget)
  55 {
  56         struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
  57         struct sk_buff *skb;
  58         int work_done = 0;
  59
  60         while (work_done < budget) {
  61                 skb = __skb_dequeue(&cell->napi_skbs);
  62                 if (!skb)
  63                         break;
  64                 napi_gro_receive(napi, skb);
  65                 work_done++;
  66         }
  67
  68         if (work_done < budget)
  69                 napi_complete_done(napi, work_done);
  70         return work_done;
  71 }
  72
  73 static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
  74 {
  75         int i;
  76
  77         gcells->cells = alloc_percpu(struct gro_cell);
  78         if (!gcells->cells)
  79                 return -ENOMEM;
  80
  81         for_each_possible_cpu(i) {
  82                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  83
  84                 __skb_queue_head_init(&cell->napi_skbs);
  85
  86                 set_bit(NAPI_STATE_NO_BUSY_POLL, &cell->napi.state);
  87
  88                 netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
  89                 napi_enable(&cell->napi);
  90         }
  91         return 0;
  92 }
  93
  94 static inline void gro_cells_destroy(struct gro_cells *gcells)
  95 {
  96         int i;
  97
  98         if (!gcells->cells)
  99                 return;
 100         for_each_possible_cpu(i) {
 101                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
 102
 103                 napi_disable(&cell->napi);
 104                 netif_napi_del(&cell->napi);
 105                 __skb_queue_purge(&cell->napi_skbs);
 106         }
 107         free_percpu(gcells->cells);
 108         gcells->cells = NULL;
 109 }
 110
 111 #endif