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/*
* Copyright (c) 2003-2008 Chelsio, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef _CHELSIO_L2T_H
#define _CHELSIO_L2T_H
#include <linux/spinlock.h>
#include "t3cdev.h"
#include <linux/atomic.h>
enum {
L2T_STATE_VALID, /* entry is up to date */
L2T_STATE_STALE, /* entry may be used but needs revalidation */
L2T_STATE_RESOLVING, /* entry needs address resolution */
L2T_STATE_UNUSED /* entry not in use */
};
struct neighbour;
struct sk_buff;
/*
* Each L2T entry plays multiple roles. First of all, it keeps state for the
* corresponding entry of the HW L2 table and maintains a queue of offload
* packets awaiting address resolution. Second, it is a node of a hash table
* chain, where the nodes of the chain are linked together through their next
* pointer. Finally, each node is a bucket of a hash table, pointing to the
* first element in its chain through its first pointer.
*/
struct l2t_entry {
u16 state; /* entry state */
u16 idx; /* entry index */
u32 addr; /* dest IP address */
int ifindex; /* neighbor's net_device's ifindex */
u16 smt_idx; /* SMT index */
u16 vlan; /* VLAN TCI (id: bits 0-11, prio: 13-15 */
struct neighbour *neigh; /* associated neighbour */
struct l2t_entry *first; /* start of hash chain */
struct l2t_entry *next; /* next l2t_entry on chain */
struct sk_buff_head arpq; /* queue of packets awaiting resolution */
spinlock_t lock;
atomic_t refcnt; /* entry reference count */
u8 dmac[6]; /* neighbour's MAC address */
};
struct l2t_data {
unsigned int nentries; /* number of entries */
struct l2t_entry *rover; /* starting point for next allocation */
atomic_t nfree; /* number of free entries */
rwlock_t lock;
struct rcu_head rcu_head; /* to handle rcu cleanup */
struct l2t_entry l2tab[] __counted_by(nentries);
};
typedef void (*arp_failure_handler_func)(struct t3cdev * dev,
struct sk_buff * skb);
/*
* Callback stored in an skb to handle address resolution failure.
*/
struct l2t_skb_cb {
arp_failure_handler_func arp_failure_handler;
};
#define L2T_SKB_CB(skb) ((struct l2t_skb_cb *)(skb)->cb)
static inline void set_arp_failure_handler(struct sk_buff *skb,
arp_failure_handler_func hnd)
{
L2T_SKB_CB(skb)->arp_failure_handler = hnd;
}
/*
* Getting to the L2 data from an offload device.
*/
#define L2DATA(cdev) (rcu_dereference((cdev)->l2opt))
#define W_TCB_L2T_IX 0
#define S_TCB_L2T_IX 7
#define M_TCB_L2T_IX 0x7ffULL
#define V_TCB_L2T_IX(x) ((x) << S_TCB_L2T_IX)
void t3_l2e_free(struct l2t_data *d, struct l2t_entry *e);
void t3_l2t_update(struct t3cdev *dev, struct neighbour *neigh);
struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct dst_entry *dst,
struct net_device *dev, const void *daddr);
int t3_l2t_send_slow(struct t3cdev *dev, struct sk_buff *skb,
struct l2t_entry *e);
void t3_l2t_send_event(struct t3cdev *dev, struct l2t_entry *e);
struct l2t_data *t3_init_l2t(unsigned int l2t_capacity);
int cxgb3_ofld_send(struct t3cdev *dev, struct sk_buff *skb);
static inline int l2t_send(struct t3cdev *dev, struct sk_buff *skb,
struct l2t_entry *e)
{
if (likely(e->state == L2T_STATE_VALID))
return cxgb3_ofld_send(dev, skb);
return t3_l2t_send_slow(dev, skb, e);
}
static inline void l2t_release(struct t3cdev *t, struct l2t_entry *e)
{
struct l2t_data *d;
rcu_read_lock();
d = L2DATA(t);
if (atomic_dec_and_test(&e->refcnt) && d)
t3_l2e_free(d, e);
rcu_read_unlock();
}
static inline void l2t_hold(struct l2t_data *d, struct l2t_entry *e)
{
if (d && atomic_add_return(1, &e->refcnt) == 1) /* 0 -> 1 transition */
atomic_dec(&d->nfree);
}
#endif