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 int res; 17 18 rcu_read_lock(); 19 if (unlikely(!(dev->flags & IFF_UP))) 20 goto drop; 21 22 if (!gcells->cells || skb_cloned(skb) || netif_elide_gro(dev)) { 23 res = netif_rx(skb); 24 goto unlock; 25 } 26 27 cell = this_cpu_ptr(gcells->cells); 28 29 if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) { 30 drop: 31 atomic_long_inc(&dev->rx_dropped); 32 kfree_skb(skb); 33 res = NET_RX_DROP; 34 goto unlock; 35 } 36 37 __skb_queue_tail(&cell->napi_skbs, skb); 38 if (skb_queue_len(&cell->napi_skbs) == 1) 39 napi_schedule(&cell->napi); 40 41 res = NET_RX_SUCCESS; 42 43 unlock: 44 rcu_read_unlock(); 45 return res; 46 } 47 EXPORT_SYMBOL(gro_cells_receive); 48 49 /* called under BH context */ 50 static int gro_cell_poll(struct napi_struct *napi, int budget) 51 { 52 struct gro_cell *cell = container_of(napi, struct gro_cell, napi); 53 struct sk_buff *skb; 54 int work_done = 0; 55 56 while (work_done < budget) { 57 skb = __skb_dequeue(&cell->napi_skbs); 58 if (!skb) 59 break; 60 napi_gro_receive(napi, skb); 61 work_done++; 62 } 63 64 if (work_done < budget) 65 napi_complete_done(napi, work_done); 66 return work_done; 67 } 68 69 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 82 set_bit(NAPI_STATE_NO_BUSY_POLL, &cell->napi.state); 83 84 netif_napi_add(dev, &cell->napi, gro_cell_poll, 85 NAPI_POLL_WEIGHT); 86 napi_enable(&cell->napi); 87 } 88 return 0; 89 } 90 EXPORT_SYMBOL(gro_cells_init); 91 92 void gro_cells_destroy(struct gro_cells *gcells) 93 { 94 int i; 95 96 if (!gcells->cells) 97 return; 98 for_each_possible_cpu(i) { 99 struct gro_cell *cell = per_cpu_ptr(gcells->cells, i); 100 101 napi_disable(&cell->napi); 102 __netif_napi_del(&cell->napi); 103 __skb_queue_purge(&cell->napi_skbs); 104 } 105 /* This barrier is needed because netpoll could access dev->napi_list 106 * under rcu protection. 107 */ 108 synchronize_net(); 109 110 free_percpu(gcells->cells); 111 gcells->cells = NULL; 112 } 113 EXPORT_SYMBOL(gro_cells_destroy); 114