xref: /openbmc/linux/include/net/gro_cells.h (revision bc5aa3a0)
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 
8 struct gro_cell {
9 	struct sk_buff_head	napi_skbs;
10 	struct napi_struct	napi;
11 };
12 
13 struct gro_cells {
14 	struct gro_cell __percpu	*cells;
15 };
16 
17 static inline int 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 		return netif_rx(skb);
24 
25 	cell = this_cpu_ptr(gcells->cells);
26 
27 	if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
28 		atomic_long_inc(&dev->rx_dropped);
29 		kfree_skb(skb);
30 		return NET_RX_DROP;
31 	}
32 
33 	__skb_queue_tail(&cell->napi_skbs, skb);
34 	if (skb_queue_len(&cell->napi_skbs) == 1)
35 		napi_schedule(&cell->napi);
36 	return NET_RX_SUCCESS;
37 }
38 
39 /* called under BH context */
40 static inline int gro_cell_poll(struct napi_struct *napi, int budget)
41 {
42 	struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
43 	struct sk_buff *skb;
44 	int work_done = 0;
45 
46 	while (work_done < budget) {
47 		skb = __skb_dequeue(&cell->napi_skbs);
48 		if (!skb)
49 			break;
50 		napi_gro_receive(napi, skb);
51 		work_done++;
52 	}
53 
54 	if (work_done < budget)
55 		napi_complete_done(napi, work_done);
56 	return work_done;
57 }
58 
59 static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
60 {
61 	int i;
62 
63 	gcells->cells = alloc_percpu(struct gro_cell);
64 	if (!gcells->cells)
65 		return -ENOMEM;
66 
67 	for_each_possible_cpu(i) {
68 		struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
69 
70 		__skb_queue_head_init(&cell->napi_skbs);
71 		netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
72 		napi_enable(&cell->napi);
73 	}
74 	return 0;
75 }
76 
77 static inline void gro_cells_destroy(struct gro_cells *gcells)
78 {
79 	int i;
80 
81 	if (!gcells->cells)
82 		return;
83 	for_each_possible_cpu(i) {
84 		struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
85 
86 		netif_napi_del(&cell->napi);
87 		__skb_queue_purge(&cell->napi_skbs);
88 	}
89 	free_percpu(gcells->cells);
90 	gcells->cells = NULL;
91 }
92 
93 #endif
94