aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/cxgb3/l2t.h
blob: c5f54796e2cbed868d8bc65a60bd127f23c995bc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/*
 * 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 l2t_entry l2tab[0];
	struct rcu_head rcu_head;	/* to handle rcu cleanup */
};

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 neighbour *neigh,
			     struct net_device *dev);
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);
void t3_free_l2t(struct l2t_data *d);

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

Privacy Policy