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 } ____cacheline_aligned_in_smp;
  12
  13 struct gro_cells {
  14         unsigned int            gro_cells_mask;
  15         struct gro_cell         *cells;
  16 };
  17
  18 static inline void gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
  19 {
  20         struct gro_cell *cell = gcells->cells;
  21         struct net_device *dev = skb->dev;
  22
  23         if (!cell || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
  24                 netif_rx(skb);
  25                 return;
  26         }
  27
  28         if (skb_rx_queue_recorded(skb))
  29                 cell += skb_get_rx_queue(skb) & gcells->gro_cells_mask;
  30
  31         if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
  32                 atomic_long_inc(&dev->rx_dropped);
  33                 kfree_skb(skb);
  34                 return;
  35         }
  36
  37         /* We run in BH context */
  38         spin_lock(&cell->napi_skbs.lock);
  39
  40         __skb_queue_tail(&cell->napi_skbs, skb);
  41         if (skb_queue_len(&cell->napi_skbs) == 1)
  42                 napi_schedule(&cell->napi);
  43
  44         spin_unlock(&cell->napi_skbs.lock);
  45 }
  46
  47 /* called unser BH context */
  48 static inline int gro_cell_poll(struct napi_struct *napi, int budget)
  49 {
  50         struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
  51         struct sk_buff *skb;
  52         int work_done = 0;
  53
  54         spin_lock(&cell->napi_skbs.lock);
  55         while (work_done < budget) {
  56                 skb = __skb_dequeue(&cell->napi_skbs);
  57                 if (!skb)
  58                         break;
  59                 spin_unlock(&cell->napi_skbs.lock);
  60                 napi_gro_receive(napi, skb);
  61                 work_done++;
  62                 spin_lock(&cell->napi_skbs.lock);
  63         }
  64
  65         if (work_done < budget)
  66                 napi_complete(napi);
  67         spin_unlock(&cell->napi_skbs.lock);
  68         return work_done;
  69 }
  70
  71 static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
  72 {
  73         int i;
  74
  75         gcells->gro_cells_mask = roundup_pow_of_two(netif_get_num_default_rss_queues()) - 1;
  76         gcells->cells = kcalloc(sizeof(struct gro_cell),
  77                                 gcells->gro_cells_mask + 1,
  78                                 GFP_KERNEL);
  79         if (!gcells->cells)
  80                 return -ENOMEM;
  81
  82         for (i = 0; i <= gcells->gro_cells_mask; i++) {
  83                 struct gro_cell *cell = gcells->cells + i;
  84
  85                 skb_queue_head_init(&cell->napi_skbs);
  86                 netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
  87                 napi_enable(&cell->napi);
  88         }
  89         return 0;
  90 }
  91
  92 static inline void gro_cells_destroy(struct gro_cells *gcells)
  93 {
  94         struct gro_cell *cell = gcells->cells;
  95         int i;
  96
  97         if (!cell)
  98                 return;
  99         for (i = 0; i <= gcells->gro_cells_mask; i++,cell++) {
 100                 netif_napi_del(&cell->napi);
 101                 skb_queue_purge(&cell->napi_skbs);
 102         }
 103         kfree(gcells->cells);
 104         gcells->cells = NULL;
 105 }
 106
 107 #endif