xref: /linux/include/net/gro_cells.h (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
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 } ____cacheline_aligned_in_smp;
12 
13 struct gro_cells {
14 	unsigned int		gro_cells_mask;
15 	struct gro_cell		*cells;
16 };
17 
18 static inline void gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
19 {
20 	unsigned long flags;
21 	struct gro_cell *cell = gcells->cells;
22 	struct net_device *dev = skb->dev;
23 
24 	if (!cell || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
25 		netif_rx(skb);
26 		return;
27 	}
28 
29 	if (skb_rx_queue_recorded(skb))
30 		cell += skb_get_rx_queue(skb) & gcells->gro_cells_mask;
31 
32 	if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
33 		atomic_long_inc(&dev->rx_dropped);
34 		kfree_skb(skb);
35 		return;
36 	}
37 
38 	spin_lock_irqsave(&cell->napi_skbs.lock, flags);
39 
40 	__skb_queue_tail(&cell->napi_skbs, skb);
41 	if (skb_queue_len(&cell->napi_skbs) == 1)
42 		napi_schedule(&cell->napi);
43 
44 	spin_unlock_irqrestore(&cell->napi_skbs.lock, flags);
45 }
46 
47 static inline int gro_cell_poll(struct napi_struct *napi, int budget)
48 {
49 	struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
50 	struct sk_buff *skb;
51 	int work_done = 0;
52 
53 	while (work_done < budget) {
54 		skb = skb_dequeue(&cell->napi_skbs);
55 		if (!skb)
56 			break;
57 
58 		napi_gro_receive(napi, skb);
59 		work_done++;
60 	}
61 
62 	if (work_done < budget)
63 		napi_complete(napi);
64 	return work_done;
65 }
66 
67 static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
68 {
69 	int i;
70 
71 	gcells->gro_cells_mask = roundup_pow_of_two(netif_get_num_default_rss_queues()) - 1;
72 	gcells->cells = kcalloc(sizeof(struct gro_cell),
73 				gcells->gro_cells_mask + 1,
74 				GFP_KERNEL);
75 	if (!gcells->cells)
76 		return -ENOMEM;
77 
78 	for (i = 0; i <= gcells->gro_cells_mask; i++) {
79 		struct gro_cell *cell = gcells->cells + i;
80 
81 		skb_queue_head_init(&cell->napi_skbs);
82 		netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
83 		napi_enable(&cell->napi);
84 	}
85 	return 0;
86 }
87 
88 static inline void gro_cells_destroy(struct gro_cells *gcells)
89 {
90 	struct gro_cell *cell = gcells->cells;
91 	int i;
92 
93 	if (!cell)
94 		return;
95 	for (i = 0; i <= gcells->gro_cells_mask; i++,cell++) {
96 		netif_napi_del(&cell->napi);
97 		skb_queue_purge(&cell->napi_skbs);
98 	}
99 	kfree(gcells->cells);
100 	gcells->cells = NULL;
101 }
102 
103 #endif
104