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
8struct gro_cell {
9	struct sk_buff_head	napi_skbs;
10	struct napi_struct	napi;
11};
12
13struct gro_cells {
14	struct gro_cell __percpu	*cells;
15};
16
17static inline void gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
18{
19	struct gro_cell *cell;
20	struct net_device *dev = skb->dev;
21
22	if (!gcells->cells || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
23		netif_rx(skb);
24		return;
25	}
26
27	cell = this_cpu_ptr(gcells->cells);
28
29	if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
30		atomic_long_inc(&dev->rx_dropped);
31		kfree_skb(skb);
32		return;
33	}
34
35	/* We run in BH context */
36	spin_lock(&cell->napi_skbs.lock);
37
38	__skb_queue_tail(&cell->napi_skbs, skb);
39	if (skb_queue_len(&cell->napi_skbs) == 1)
40		napi_schedule(&cell->napi);
41
42	spin_unlock(&cell->napi_skbs.lock);
43}
44
45/* called unser BH context */
46static inline int gro_cell_poll(struct napi_struct *napi, int budget)
47{
48	struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
49	struct sk_buff *skb;
50	int work_done = 0;
51
52	spin_lock(&cell->napi_skbs.lock);
53	while (work_done < budget) {
54		skb = __skb_dequeue(&cell->napi_skbs);
55		if (!skb)
56			break;
57		spin_unlock(&cell->napi_skbs.lock);
58		napi_gro_receive(napi, skb);
59		work_done++;
60		spin_lock(&cell->napi_skbs.lock);
61	}
62
63	if (work_done < budget)
64		napi_complete(napi);
65	spin_unlock(&cell->napi_skbs.lock);
66	return work_done;
67}
68
69static inline 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		netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
82		napi_enable(&cell->napi);
83	}
84	return 0;
85}
86
87static inline void gro_cells_destroy(struct gro_cells *gcells)
88{
89	int i;
90
91	if (!gcells->cells)
92		return;
93	for_each_possible_cpu(i) {
94		struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
95		netif_napi_del(&cell->napi);
96		skb_queue_purge(&cell->napi_skbs);
97	}
98	free_percpu(gcells->cells);
99	gcells->cells = NULL;
100}
101
102#endif
103