1 /*
2  * This file is part of the Chelsio T4 Ethernet driver for Linux.
3  *
4  * Copyright (c) 2003-2010 Chelsio Communications, Inc. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  */
34 
35 #ifndef __CXGB4_L2T_H
36 #define __CXGB4_L2T_H
37 
38 #include <linux/spinlock.h>
39 #include <linux/if_ether.h>
40 #include <linux/atomic.h>
41 
42 struct adapter;
43 struct l2t_data;
44 struct neighbour;
45 struct net_device;
46 struct file_operations;
47 struct cpl_l2t_write_rpl;
48 
49 /*
50  * Each L2T entry plays multiple roles.  First of all, it keeps state for the
51  * corresponding entry of the HW L2 table and maintains a queue of offload
52  * packets awaiting address resolution.  Second, it is a node of a hash table
53  * chain, where the nodes of the chain are linked together through their next
54  * pointer.  Finally, each node is a bucket of a hash table, pointing to the
55  * first element in its chain through its first pointer.
56  */
57 struct l2t_entry {
58 	u16 state;                  /* entry state */
59 	u16 idx;                    /* entry index */
60 	u32 addr[4];                /* next hop IP or IPv6 address */
61 	int ifindex;                /* neighbor's net_device's ifindex */
62 	struct neighbour *neigh;    /* associated neighbour */
63 	struct l2t_entry *first;    /* start of hash chain */
64 	struct l2t_entry *next;     /* next l2t_entry on chain */
65 	struct sk_buff *arpq_head;  /* queue of packets awaiting resolution */
66 	struct sk_buff *arpq_tail;
67 	spinlock_t lock;
68 	atomic_t refcnt;            /* entry reference count */
69 	u16 hash;                   /* hash bucket the entry is on */
70 	u16 vlan;                   /* VLAN TCI (id: bits 0-11, prio: 13-15 */
71 	u8 v6;                      /* whether entry is for IPv6 */
72 	u8 lport;                   /* associated offload logical interface */
73 	u8 dmac[ETH_ALEN];          /* neighbour's MAC address */
74 };
75 
76 typedef void (*arp_err_handler_t)(void *handle, struct sk_buff *skb);
77 
78 /*
79  * Callback stored in an skb to handle address resolution failure.
80  */
81 struct l2t_skb_cb {
82 	void *handle;
83 	arp_err_handler_t arp_err_handler;
84 };
85 
86 #define L2T_SKB_CB(skb) ((struct l2t_skb_cb *)(skb)->cb)
87 
t4_set_arp_err_handler(struct sk_buff * skb,void * handle,arp_err_handler_t handler)88 static inline void t4_set_arp_err_handler(struct sk_buff *skb, void *handle,
89 					  arp_err_handler_t handler)
90 {
91 	L2T_SKB_CB(skb)->handle = handle;
92 	L2T_SKB_CB(skb)->arp_err_handler = handler;
93 }
94 
95 void cxgb4_l2t_release(struct l2t_entry *e);
96 int cxgb4_l2t_send(struct net_device *dev, struct sk_buff *skb,
97 		   struct l2t_entry *e);
98 struct l2t_entry *cxgb4_l2t_get(struct l2t_data *d, struct neighbour *neigh,
99 				const struct net_device *physdev,
100 				unsigned int priority);
101 
102 void t4_l2t_update(struct adapter *adap, struct neighbour *neigh);
103 struct l2t_data *t4_init_l2t(void);
104 void do_l2t_write_rpl(struct adapter *p, const struct cpl_l2t_write_rpl *rpl);
105 
106 extern const struct file_operations t4_l2t_fops;
107 #endif  /* __CXGB4_L2T_H */
108