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(&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(1, &e->refcnt) == 1) /* 0 -> 1 transition */ 145 atomic_dec(&d->nfree); 146 } 147 148 #endif 149