1 /*
2  * This file is part of the Chelsio T4 Ethernet driver for Linux.
3  *
4  * Copyright (c) 2003-2014 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 #define VLAN_NONE 0xfff
43 
44 enum { L2T_SIZE = 4096 };     /* # of L2T entries */
45 
46 enum {
47 	L2T_STATE_VALID,      /* entry is up to date */
48 	L2T_STATE_STALE,      /* entry may be used but needs revalidation */
49 	L2T_STATE_RESOLVING,  /* entry needs address resolution */
50 	L2T_STATE_SYNC_WRITE, /* synchronous write of entry underway */
51 	L2T_STATE_NOARP,      /* Netdev down or removed*/
52 
53 	/* when state is one of the below the entry is not hashed */
54 	L2T_STATE_SWITCHING,  /* entry is being used by a switching filter */
55 	L2T_STATE_UNUSED      /* entry not in use */
56 };
57 
58 struct adapter;
59 struct l2t_data;
60 struct neighbour;
61 struct net_device;
62 struct file_operations;
63 struct cpl_l2t_write_rpl;
64 
65 /*
66  * Each L2T entry plays multiple roles.  First of all, it keeps state for the
67  * corresponding entry of the HW L2 table and maintains a queue of offload
68  * packets awaiting address resolution.  Second, it is a node of a hash table
69  * chain, where the nodes of the chain are linked together through their next
70  * pointer.  Finally, each node is a bucket of a hash table, pointing to the
71  * first element in its chain through its first pointer.
72  */
73 struct l2t_entry {
74 	u16 state;                  /* entry state */
75 	u16 idx;                    /* entry index within in-memory table */
76 	u32 addr[4];                /* next hop IP or IPv6 address */
77 	int ifindex;                /* neighbor's net_device's ifindex */
78 	struct neighbour *neigh;    /* associated neighbour */
79 	struct l2t_entry *first;    /* start of hash chain */
80 	struct l2t_entry *next;     /* next l2t_entry on chain */
81 	struct sk_buff_head arpq;   /* packet queue awaiting resolution */
82 	spinlock_t lock;
83 	atomic_t refcnt;            /* entry reference count */
84 	u16 hash;                   /* hash bucket the entry is on */
85 	u16 vlan;                   /* VLAN TCI (id: bits 0-11, prio: 13-15 */
86 	u8 v6;                      /* whether entry is for IPv6 */
87 	u8 lport;                   /* associated offload logical interface */
88 	u8 dmac[ETH_ALEN];          /* neighbour's MAC address */
89 };
90 
91 typedef void (*arp_err_handler_t)(void *handle, struct sk_buff *skb);
92 
93 /*
94  * Callback stored in an skb to handle address resolution failure.
95  */
96 struct l2t_skb_cb {
97 	void *handle;
98 	arp_err_handler_t arp_err_handler;
99 };
100 
101 #define L2T_SKB_CB(skb) ((struct l2t_skb_cb *)(skb)->cb)
102 
103 static inline void t4_set_arp_err_handler(struct sk_buff *skb, void *handle,
104 					  arp_err_handler_t handler)
105 {
106 	L2T_SKB_CB(skb)->handle = handle;
107 	L2T_SKB_CB(skb)->arp_err_handler = handler;
108 }
109 
110 void cxgb4_l2t_release(struct l2t_entry *e);
111 int cxgb4_l2t_send(struct net_device *dev, struct sk_buff *skb,
112 		   struct l2t_entry *e);
113 struct l2t_entry *cxgb4_l2t_get(struct l2t_data *d, struct neighbour *neigh,
114 				const struct net_device *physdev,
115 				unsigned int priority);
116 u64 cxgb4_select_ntuple(struct net_device *dev,
117 			const struct l2t_entry *l2t);
118 struct l2t_entry *cxgb4_l2t_alloc_switching(struct net_device *dev, u16 vlan,
119 					    u8 port, u8 *dmac);
120 void t4_l2t_update(struct adapter *adap, struct neighbour *neigh);
121 struct l2t_entry *t4_l2t_alloc_switching(struct adapter *adap, u16 vlan,
122 					 u8 port, u8 *dmac);
123 struct l2t_data *t4_init_l2t(unsigned int l2t_start, unsigned int l2t_end);
124 void do_l2t_write_rpl(struct adapter *p, const struct cpl_l2t_write_rpl *rpl);
125 bool cxgb4_check_l2t_valid(struct l2t_entry *e);
126 
127 extern const struct file_operations t4_l2t_fops;
128 #endif  /* __CXGB4_L2T_H */
129