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	__skb_queue_tail(&cell->napi_skbs, skb);
36	if (skb_queue_len(&cell->napi_skbs) == 1)
37		napi_schedule(&cell->napi);
38}
39
40/* called under BH context */
41static inline int gro_cell_poll(struct napi_struct *napi, int budget)
42{
43	struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
44	struct sk_buff *skb;
45	int work_done = 0;
46
47	while (work_done < budget) {
48		skb = __skb_dequeue(&cell->napi_skbs);
49		if (!skb)
50			break;
51		napi_gro_receive(napi, skb);
52		work_done++;
53	}
54
55	if (work_done < budget)
56		napi_complete_done(napi, work_done);
57	return work_done;
58}
59
60static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
61{
62	int i;
63
64	gcells->cells = alloc_percpu(struct gro_cell);
65	if (!gcells->cells)
66		return -ENOMEM;
67
68	for_each_possible_cpu(i) {
69		struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
70
71		__skb_queue_head_init(&cell->napi_skbs);
72		netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
73		napi_enable(&cell->napi);
74	}
75	return 0;
76}
77
78static inline 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
94#endif