xref: /openbmc/linux/include/net/gro_cells.h (revision c42858ea)
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 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 */
41 static 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 
60 static 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 
78 static 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
95