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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 two5 * licenses. You may choose to be licensed under the terms of the GNU6 * General Public License (GPL) Version 2, available from the file7 * COPYING in the main directory of this source tree, or the8 * OpenIB.org BSD license below:9 *10 * Redistribution and use in source and binary forms, with or11 * without modification, are permitted provided that the following12 * conditions are met:13 *14 * - Redistributions of source code must retain the above15 * copyright notice, this list of conditions and the following16 * disclaimer.17 *18 * - Redistributions in binary form must reproduce the above19 * copyright notice, this list of conditions and the following20 * disclaimer in the documentation and/or other materials21 * 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 OF25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE30 * SOFTWARE.31 */32#ifndef _CHELSIO_L2T_H33#define _CHELSIO_L2T_H34 35#include <linux/spinlock.h>36#include "t3cdev.h"37#include <linux/atomic.h>38 39enum {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 46struct neighbour;47struct sk_buff;48 49/*50 * Each L2T entry plays multiple roles. First of all, it keeps state for the51 * corresponding entry of the HW L2 table and maintains a queue of offload52 * packets awaiting address resolution. Second, it is a node of a hash table53 * chain, where the nodes of the chain are linked together through their next54 * pointer. Finally, each node is a bucket of a hash table, pointing to the55 * first element in its chain through its first pointer.56 */57struct 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 73struct 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 82typedef 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 */88struct 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 94static 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 0106#define S_TCB_L2T_IX 7107#define M_TCB_L2T_IX 0x7ffULL108#define V_TCB_L2T_IX(x) ((x) << S_TCB_L2T_IX)109 110void t3_l2e_free(struct l2t_data *d, struct l2t_entry *e);111void t3_l2t_update(struct t3cdev *dev, struct neighbour *neigh);112struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct dst_entry *dst,113 struct net_device *dev, const void *daddr);114int t3_l2t_send_slow(struct t3cdev *dev, struct sk_buff *skb,115 struct l2t_entry *e);116void t3_l2t_send_event(struct t3cdev *dev, struct l2t_entry *e);117struct l2t_data *t3_init_l2t(unsigned int l2t_capacity);118 119int cxgb3_ofld_send(struct t3cdev *dev, struct sk_buff *skb);120 121static 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 129static 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 142static 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#endif149