1 | /* |
2 | * Copyright (c) 2003-2008 Chelsio, Inc. All rights reserved. |
3 | * |
4 | * This software is available to you under a choice of one of two |
5 | * licenses. You may choose to be licensed under the terms of the GNU |
6 | * General Public License (GPL) Version 2, available from the file |
7 | * COPYING in the main directory of this source tree, or the |
8 | * OpenIB.org BSD license below: |
9 | * |
10 | * Redistribution and use in source and binary forms, with or |
11 | * without modification, are permitted provided that the following |
12 | * conditions are met: |
13 | * |
14 | * - Redistributions of source code must retain the above |
15 | * copyright notice, this list of conditions and the following |
16 | * disclaimer. |
17 | * |
18 | * - Redistributions in binary form must reproduce the above |
19 | * copyright notice, this list of conditions and the following |
20 | * disclaimer in the documentation and/or other materials |
21 | * provided with the distribution. |
22 | * |
23 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
24 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
25 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
26 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
27 | * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
28 | * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
29 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
30 | * SOFTWARE. |
31 | */ |
32 | #ifndef _CHELSIO_L2T_H |
33 | #define _CHELSIO_L2T_H |
34 | |
35 | #include <linux/spinlock.h> |
36 | #include "t3cdev.h" |
37 | #include <linux/atomic.h> |
38 | |
39 | enum { |
40 | L2T_STATE_VALID, /* entry is up to date */ |
41 | L2T_STATE_STALE, /* entry may be used but needs revalidation */ |
42 | L2T_STATE_RESOLVING, /* entry needs address resolution */ |
43 | L2T_STATE_UNUSED /* entry not in use */ |
44 | }; |
45 | |
46 | struct neighbour; |
47 | struct sk_buff; |
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; /* dest IP address */ |
61 | int ifindex; /* neighbor's net_device's ifindex */ |
62 | u16 smt_idx; /* SMT index */ |
63 | u16 vlan; /* VLAN TCI (id: bits 0-11, prio: 13-15 */ |
64 | struct neighbour *neigh; /* associated neighbour */ |
65 | struct l2t_entry *first; /* start of hash chain */ |
66 | struct l2t_entry *next; /* next l2t_entry on chain */ |
67 | struct sk_buff_head arpq; /* queue of packets awaiting resolution */ |
68 | spinlock_t lock; |
69 | atomic_t refcnt; /* entry reference count */ |
70 | u8 dmac[6]; /* neighbour's MAC address */ |
71 | }; |
72 | |
73 | struct l2t_data { |
74 | unsigned int nentries; /* number of entries */ |
75 | struct l2t_entry *rover; /* starting point for next allocation */ |
76 | atomic_t nfree; /* number of free entries */ |
77 | rwlock_t lock; |
78 | struct rcu_head rcu_head; /* to handle rcu cleanup */ |
79 | struct l2t_entry l2tab[] __counted_by(nentries); |
80 | }; |
81 | |
82 | typedef void (*arp_failure_handler_func)(struct t3cdev * dev, |
83 | struct sk_buff * skb); |
84 | |
85 | /* |
86 | * Callback stored in an skb to handle address resolution failure. |
87 | */ |
88 | struct l2t_skb_cb { |
89 | arp_failure_handler_func arp_failure_handler; |
90 | }; |
91 | |
92 | #define L2T_SKB_CB(skb) ((struct l2t_skb_cb *)(skb)->cb) |
93 | |
94 | static inline void set_arp_failure_handler(struct sk_buff *skb, |
95 | arp_failure_handler_func hnd) |
96 | { |
97 | L2T_SKB_CB(skb)->arp_failure_handler = hnd; |
98 | } |
99 | |
100 | /* |
101 | * Getting to the L2 data from an offload device. |
102 | */ |
103 | #define L2DATA(cdev) (rcu_dereference((cdev)->l2opt)) |
104 | |
105 | #define W_TCB_L2T_IX 0 |
106 | #define S_TCB_L2T_IX 7 |
107 | #define M_TCB_L2T_IX 0x7ffULL |
108 | #define V_TCB_L2T_IX(x) ((x) << S_TCB_L2T_IX) |
109 | |
110 | void t3_l2e_free(struct l2t_data *d, struct l2t_entry *e); |
111 | void t3_l2t_update(struct t3cdev *dev, struct neighbour *neigh); |
112 | struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct dst_entry *dst, |
113 | struct net_device *dev, const void *daddr); |
114 | int t3_l2t_send_slow(struct t3cdev *dev, struct sk_buff *skb, |
115 | struct l2t_entry *e); |
116 | void t3_l2t_send_event(struct t3cdev *dev, struct l2t_entry *e); |
117 | struct l2t_data *t3_init_l2t(unsigned int l2t_capacity); |
118 | |
119 | int cxgb3_ofld_send(struct t3cdev *dev, struct sk_buff *skb); |
120 | |
121 | static inline int l2t_send(struct t3cdev *dev, struct sk_buff *skb, |
122 | struct l2t_entry *e) |
123 | { |
124 | if (likely(e->state == L2T_STATE_VALID)) |
125 | return cxgb3_ofld_send(dev, skb); |
126 | return t3_l2t_send_slow(dev, skb, e); |
127 | } |
128 | |
129 | static inline void l2t_release(struct t3cdev *t, struct l2t_entry *e) |
130 | { |
131 | struct l2t_data *d; |
132 | |
133 | rcu_read_lock(); |
134 | d = L2DATA(t); |
135 | |
136 | if (atomic_dec_and_test(v: &e->refcnt) && d) |
137 | t3_l2e_free(d, e); |
138 | |
139 | rcu_read_unlock(); |
140 | } |
141 | |
142 | static inline void l2t_hold(struct l2t_data *d, struct l2t_entry *e) |
143 | { |
144 | if (d && atomic_add_return(i: 1, v: &e->refcnt) == 1) /* 0 -> 1 transition */ |
145 | atomic_dec(v: &d->nfree); |
146 | } |
147 | |
148 | #endif |
149 | |