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|
/*
* This file is part of the Chelsio T4 Ethernet driver for Linux.
*
* Copyright (c) 2003-2014 Chelsio Communications, 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.
*/
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if.h>
#include <linux/if_vlan.h>
#include <linux/jhash.h>
#include <linux/module.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <net/neighbour.h>
#include "cxgb4.h"
#include "l2t.h"
#include "t4_msg.h"
#include "t4fw_api.h"
#include "t4_regs.h"
#include "t4_values.h"
/* identifies sync vs async L2T_WRITE_REQs */
#define SYNC_WR_S 12
#define SYNC_WR_V(x) ((x) << SYNC_WR_S)
#define SYNC_WR_F SYNC_WR_V(1)
struct l2t_data {
unsigned int l2t_start; /* start index of our piece of the L2T */
unsigned int l2t_size; /* number of entries in l2tab */
rwlock_t lock;
atomic_t nfree; /* number of free entries */
struct l2t_entry *rover; /* starting point for next allocation */
struct l2t_entry l2tab[0]; /* MUST BE LAST */
};
static inline unsigned int vlan_prio(const struct l2t_entry *e)
{
return e->vlan >> VLAN_PRIO_SHIFT;
}
static inline void l2t_hold(struct l2t_data *d, struct l2t_entry *e)
{
if (atomic_add_return(1, &e->refcnt) == 1) /* 0 -> 1 transition */
atomic_dec(&d->nfree);
}
/*
* To avoid having to check address families we do not allow v4 and v6
* neighbors to be on the same hash chain. We keep v4 entries in the first
* half of available hash buckets and v6 in the second. We need at least two
* entries in our L2T for this scheme to work.
*/
enum {
L2T_MIN_HASH_BUCKETS = 2,
};
static inline unsigned int arp_hash(struct l2t_data *d, const u32 *key,
int ifindex)
{
unsigned int l2t_size_half = d->l2t_size / 2;
return jhash_2words(*key, ifindex, 0) % l2t_size_half;
}
static inline unsigned int ipv6_hash(struct l2t_data *d, const u32 *key,
int ifindex)
{
unsigned int l2t_size_half = d->l2t_size / 2;
u32 xor = key[0] ^ key[1] ^ key[2] ^ key[3];
return (l2t_size_half +
(jhash_2words(xor, ifindex, 0) % l2t_size_half));
}
static unsigned int addr_hash(struct l2t_data *d, const u32 *addr,
int addr_len, int ifindex)
{
return addr_len == 4 ? arp_hash(d, addr, ifindex) :
ipv6_hash(d, addr, ifindex);
}
/*
* Checks if an L2T entry is for the given IP/IPv6 address. It does not check
* whether the L2T entry and the address are of the same address family.
* Callers ensure an address is only checked against L2T entries of the same
* family, something made trivial by the separation of IP and IPv6 hash chains
* mentioned above. Returns 0 if there's a match,
*/
static int addreq(const struct l2t_entry *e, const u32 *addr)
{
if (e->v6)
return (e->addr[0] ^ addr[0]) | (e->addr[1] ^ addr[1]) |
(e->addr[2] ^ addr[2]) | (e->addr[3] ^ addr[3]);
return e->addr[0] ^ addr[0];
}
static void neigh_replace(struct l2t_entry *e, struct neighbour *n)
{
neigh_hold(n);
if (e->neigh)
neigh_release(e->neigh);
e->neigh = n;
}
/*
* Write an L2T entry. Must be called with the entry locked.
* The write may be synchronous or asynchronous.
*/
static int write_l2e(struct adapter *adap, struct l2t_entry *e, int sync)
{
struct l2t_data *d = adap->l2t;
unsigned int l2t_idx = e->idx + d->l2t_start;
struct sk_buff *skb;
struct cpl_l2t_write_req *req;
skb = alloc_skb(sizeof(*req), GFP_ATOMIC);
if (!skb)
return -ENOMEM;
req = (struct cpl_l2t_write_req *)__skb_put(skb, sizeof(*req));
INIT_TP_WR(req, 0);
OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_L2T_WRITE_REQ,
l2t_idx | (sync ? SYNC_WR_F : 0) |
TID_QID_V(adap->sge.fw_evtq.abs_id)));
req->params = htons(L2T_W_PORT_V(e->lport) | L2T_W_NOREPLY_V(!sync));
req->l2t_idx = htons(l2t_idx);
req->vlan = htons(e->vlan);
if (e->neigh && !(e->neigh->dev->flags & IFF_LOOPBACK))
memcpy(e->dmac, e->neigh->ha, sizeof(e->dmac));
memcpy(req->dst_mac, e->dmac, sizeof(req->dst_mac));
t4_mgmt_tx(adap, skb);
if (sync && e->state != L2T_STATE_SWITCHING)
e->state = L2T_STATE_SYNC_WRITE;
return 0;
}
/*
* Send packets waiting in an L2T entry's ARP queue. Must be called with the
* entry locked.
*/
static void send_pending(struct adapter *adap, struct l2t_entry *e)
{
struct sk_buff *skb;
while ((skb = __skb_dequeue(&e->arpq)) != NULL)
t4_ofld_send(adap, skb);
}
/*
* Process a CPL_L2T_WRITE_RPL. Wake up the ARP queue if it completes a
* synchronous L2T_WRITE. Note that the TID in the reply is really the L2T
* index it refers to.
*/
void
|