net/core/gro_cells.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/skbuff.h>
   3 #include <linux/slab.h>
   4 #include <linux/netdevice.h>
   5 #include <net/gro_cells.h>
   6
   7 struct gro_cell {
   8         struct sk_buff_head     napi_skbs;
   9         struct napi_struct      napi;
  10 };
  11
  12 int gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
  13 {
  14         struct net_device *dev = skb->dev;
  15         struct gro_cell *cell;
  16
  17         if (!gcells->cells || skb_cloned(skb) || netif_elide_gro(dev))
  18                 return netif_rx(skb);
  19
  20         cell = this_cpu_ptr(gcells->cells);
  21
  22         if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
  23                 atomic_long_inc(&dev->rx_dropped);
  24                 kfree_skb(skb);
  25                 return NET_RX_DROP;
  26         }
  27
  28         __skb_queue_tail(&cell->napi_skbs, skb);
  29         if (skb_queue_len(&cell->napi_skbs) == 1)
  30                 napi_schedule(&cell->napi);
  31         return NET_RX_SUCCESS;
  32 }
  33 EXPORT_SYMBOL(gro_cells_receive);
  34
  35 /* called under BH context */
  36 static int gro_cell_poll(struct napi_struct *napi, int budget)
  37 {
  38         struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
  39         struct sk_buff *skb;
  40         int work_done = 0;
  41
  42         while (work_done < budget) {
  43                 skb = __skb_dequeue(&cell->napi_skbs);
  44                 if (!skb)
  45                         break;
  46                 napi_gro_receive(napi, skb);
  47                 work_done++;
  48         }
  49
  50         if (work_done < budget)
  51                 napi_complete_done(napi, work_done);
  52         return work_done;
  53 }
  54
  55 int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
  56 {
  57         int i;
  58
  59         gcells->cells = alloc_percpu(struct gro_cell);
  60         if (!gcells->cells)
  61                 return -ENOMEM;
  62
  63         for_each_possible_cpu(i) {
  64                 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
  65
  66                 __skb_queue_head_init(&cell->napi_skbs);
  67
  68                 set_bit(NAPI_STATE_NO_BUSY_POLL, &cell->napi.state);
  69
  70                 netif_napi_add(dev, &cell->napi, gro_cell_poll,
  71                                NAPI_POLL_WEIGHT);
  72                 napi_enable(&cell->napi);
  73         }
  74         return 0;
  75 }
  76 EXPORT_SYMBOL(gro_cells_init);
  77
  78 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 EXPORT_SYMBOL(gro_cells_destroy);