LXR linux/net/core/gro

   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
   7struct gro_cell {
   8        struct sk_buff_head     napi_skbs;
   9        struct napi_struct      napi;
  10};
  11
  12int 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}
  33EXPORT_SYMBOL(gro_cells_receive);
  34
  35/* called under BH context */
  36static 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
  55int 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}
  76EXPORT_SYMBOL(gro_cells_init);
  77
  78void 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}
  93EXPORT_SYMBOL(gro_cells_destroy);
  94