1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/skbuff.h>
3*4882a593Smuzhiyun #include <linux/slab.h>
4*4882a593Smuzhiyun #include <linux/netdevice.h>
5*4882a593Smuzhiyun #include <net/gro_cells.h>
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun struct gro_cell {
8*4882a593Smuzhiyun struct sk_buff_head napi_skbs;
9*4882a593Smuzhiyun struct napi_struct napi;
10*4882a593Smuzhiyun };
11*4882a593Smuzhiyun
gro_cells_receive(struct gro_cells * gcells,struct sk_buff * skb)12*4882a593Smuzhiyun int gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun struct net_device *dev = skb->dev;
15*4882a593Smuzhiyun struct gro_cell *cell;
16*4882a593Smuzhiyun int res;
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun rcu_read_lock();
19*4882a593Smuzhiyun if (unlikely(!(dev->flags & IFF_UP)))
20*4882a593Smuzhiyun goto drop;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun if (!gcells->cells || skb_cloned(skb) || netif_elide_gro(dev)) {
23*4882a593Smuzhiyun res = netif_rx(skb);
24*4882a593Smuzhiyun goto unlock;
25*4882a593Smuzhiyun }
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun cell = this_cpu_ptr(gcells->cells);
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun if (skb_queue_len(&cell->napi_skbs) > READ_ONCE(netdev_max_backlog)) {
30*4882a593Smuzhiyun drop:
31*4882a593Smuzhiyun atomic_long_inc(&dev->rx_dropped);
32*4882a593Smuzhiyun kfree_skb(skb);
33*4882a593Smuzhiyun res = NET_RX_DROP;
34*4882a593Smuzhiyun goto unlock;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun __skb_queue_tail(&cell->napi_skbs, skb);
38*4882a593Smuzhiyun if (skb_queue_len(&cell->napi_skbs) == 1)
39*4882a593Smuzhiyun napi_schedule(&cell->napi);
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun res = NET_RX_SUCCESS;
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun unlock:
44*4882a593Smuzhiyun rcu_read_unlock();
45*4882a593Smuzhiyun return res;
46*4882a593Smuzhiyun }
47*4882a593Smuzhiyun EXPORT_SYMBOL(gro_cells_receive);
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun /* called under BH context */
gro_cell_poll(struct napi_struct * napi,int budget)50*4882a593Smuzhiyun static int gro_cell_poll(struct napi_struct *napi, int budget)
51*4882a593Smuzhiyun {
52*4882a593Smuzhiyun struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
53*4882a593Smuzhiyun struct sk_buff *skb;
54*4882a593Smuzhiyun int work_done = 0;
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun while (work_done < budget) {
57*4882a593Smuzhiyun skb = __skb_dequeue(&cell->napi_skbs);
58*4882a593Smuzhiyun if (!skb)
59*4882a593Smuzhiyun break;
60*4882a593Smuzhiyun napi_gro_receive(napi, skb);
61*4882a593Smuzhiyun work_done++;
62*4882a593Smuzhiyun }
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun if (work_done < budget)
65*4882a593Smuzhiyun napi_complete_done(napi, work_done);
66*4882a593Smuzhiyun return work_done;
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun
gro_cells_init(struct gro_cells * gcells,struct net_device * dev)69*4882a593Smuzhiyun int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
70*4882a593Smuzhiyun {
71*4882a593Smuzhiyun int i;
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun gcells->cells = alloc_percpu(struct gro_cell);
74*4882a593Smuzhiyun if (!gcells->cells)
75*4882a593Smuzhiyun return -ENOMEM;
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun for_each_possible_cpu(i) {
78*4882a593Smuzhiyun struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun __skb_queue_head_init(&cell->napi_skbs);
81*4882a593Smuzhiyun
82*4882a593Smuzhiyun set_bit(NAPI_STATE_NO_BUSY_POLL, &cell->napi.state);
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun netif_napi_add(dev, &cell->napi, gro_cell_poll,
85*4882a593Smuzhiyun NAPI_POLL_WEIGHT);
86*4882a593Smuzhiyun napi_enable(&cell->napi);
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun return 0;
89*4882a593Smuzhiyun }
90*4882a593Smuzhiyun EXPORT_SYMBOL(gro_cells_init);
91*4882a593Smuzhiyun
gro_cells_destroy(struct gro_cells * gcells)92*4882a593Smuzhiyun void gro_cells_destroy(struct gro_cells *gcells)
93*4882a593Smuzhiyun {
94*4882a593Smuzhiyun int i;
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun if (!gcells->cells)
97*4882a593Smuzhiyun return;
98*4882a593Smuzhiyun for_each_possible_cpu(i) {
99*4882a593Smuzhiyun struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
100*4882a593Smuzhiyun
101*4882a593Smuzhiyun napi_disable(&cell->napi);
102*4882a593Smuzhiyun __netif_napi_del(&cell->napi);
103*4882a593Smuzhiyun __skb_queue_purge(&cell->napi_skbs);
104*4882a593Smuzhiyun }
105*4882a593Smuzhiyun /* This barrier is needed because netpoll could access dev->napi_list
106*4882a593Smuzhiyun * under rcu protection.
107*4882a593Smuzhiyun */
108*4882a593Smuzhiyun synchronize_net();
109*4882a593Smuzhiyun
110*4882a593Smuzhiyun free_percpu(gcells->cells);
111*4882a593Smuzhiyun gcells->cells = NULL;
112*4882a593Smuzhiyun }
113*4882a593Smuzhiyun EXPORT_SYMBOL(gro_cells_destroy);
114