diff options
Diffstat (limited to 'drivers/net/cxgb4/l2t.c')
| -rw-r--r-- | drivers/net/cxgb4/l2t.c | 624 |
1 files changed, 624 insertions, 0 deletions
diff --git a/drivers/net/cxgb4/l2t.c b/drivers/net/cxgb4/l2t.c new file mode 100644 index 000000000000..9f96724a133a --- /dev/null +++ b/drivers/net/cxgb4/l2t.c @@ -0,0 +1,624 @@ +/* + * This file is part of the Chelsio T4 Ethernet driver for Linux. + * + * Copyright (c) 2003-2010 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 <net/neighbour.h> +#include "cxgb4.h" +#include "l2t.h" +#include "t4_msg.h" +#include "t4fw_api.h" + +#define VLAN_NONE 0xfff + +/* identifies sync vs async L2T_WRITE_REQs */ +#define F_SYNC_WR (1 << 12) + +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_SYNC_WRITE, /* synchronous write of entry underway */ + + /* when state is one of the below the entry is not hashed */ + L2T_STATE_SWITCHING, /* entry is being used by a switching filter */ + L2T_STATE_UNUSED /* entry not in use */ +}; + +struct l2t_data { + rwlock_t lock; + atomic_t nfree; /* number of free entries */ + struct l2t_entry *rover; /* starting point for next allocation */ + struct l2t_entry l2tab[L2T_SIZE]; +}; + +static inline unsigned int vlan_prio(const struct l2t_entry *e) +{ + return e->vlan >> 13; +} + +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. + */ +enum { + L2T_SZ_HALF = L2T_SIZE / 2, + L2T_HASH_MASK = L2T_SZ_HALF - 1 +}; + +static inline unsigned int arp_hash(const u32 *key, int ifindex) +{ + return jhash_2words(*key, ifindex, 0) & L2T_HASH_MASK; +} + +static inline unsigned int ipv6_hash(const u32 *key, int ifindex) +{ + u32 xor = key[0] ^ key[1] ^ key[2] ^ key[3]; + + return L2T_SZ_HALF + (jhash_2words(xor, ifindex, 0) & L2T_HASH_MASK); +} + +static unsigned int addr_hash(const u32 *addr, int addr_len, int ifindex) +{ + return addr_len == 4 ? arp_hash(addr, ifindex) : + ipv6_hash(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 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, + e->idx | (sync ? F_SYNC_WR : 0) | + TID_QID(adap->sge.fw_evtq.abs_id))); + req->params = htons(L2T_W_PORT(e->lport) | L2T_W_NOREPLY(!sync)); + req->l2t_idx = htons(e->idx); + req->vlan = htons(e->vlan); + if (e->neigh) + memcpy(e->dmac, e->neigh->ha, sizeof(e->dmac)); + memcpy(req->dst_mac, e->dmac, sizeof(req->dst_mac)); + + set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0); + t4_ofld_send(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) +{ + while (e->arpq_head) { + struct sk_buff *skb = e->arpq_head; + + e->arpq_head = skb->next; + skb->next = NULL; + t4_ofld_send(adap, skb); + } + e->arpq_tail = NULL; +} + +/* + * 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 do_l2t_write_rpl(struct adapter *adap, const struct cpl_l2t_write_rpl *rpl) +{ + unsigned int tid = GET_TID(rpl); + unsigned int idx = tid & (L2T_SIZE - 1); + + if (unlikely(rpl->status != CPL_ERR_NONE)) { + dev_err(adap->pdev_dev, + "Unexpected L2T_WRITE_RPL status %u for entry %u\n", + rpl->status, idx); + return; + } + + if (tid & F_SYNC_WR) { + struct l2t_entry *e = &adap->l2t->l2tab[idx]; + + spin_lock(&e->lock); + if (e->state != L2T_STATE_SWITCHING) { + send_pending(adap, e); + e->state = (e->neigh->nud_state & NUD_STALE) ? + L2T_STATE_STALE : L2T_STATE_VALID; + } + spin_unlock(&e->lock); + } +} + +/* + * Add a packet to an L2T entry's queue of packets awaiting resolution. + * Must be called with the entry's lock held. + */ +static inline void arpq_enqueue(struct l2t_entry *e, struct sk_buff *skb) +{ + skb->next = NULL; + if (e->arpq_head) + e->arpq_tail->next = skb; + else + e->arpq_head = skb; + e->arpq_tail = skb; +} + +int cxgb4_l2t_send(struct net_device *dev, struct sk_buff *skb, + struct l2t_entry *e) +{ + struct adapter *adap = netdev2adap(dev); + +again: + switch (e->state) { + case L2T_STATE_STALE: /* entry is stale, kick off revalidation */ + neigh_event_send(e->neigh, NULL); + spin_lock_bh(&e->lock); + if (e->state == L2T_STATE_STALE) + e->state = L2T_STATE_VALID; + spin_unlock_bh(&e->lock); + case L2T_STATE_VALID: /* fast-path, send the packet on */ + return t4_ofld_send(adap, skb); + case L2T_STATE_RESOLVING: + case L2T_STATE_SYNC_WRITE: + spin_lock_bh(&e->lock); + if (e->state != L2T_STATE_SYNC_WRITE && + e->state != L2T_STATE_RESOLVING) { + spin_unlock_bh(&e->lock); + goto again; + } + arpq_enqueue(e, skb); + spin_unlock_bh(&e->lock); + + if (e->state == L2T_STATE_RESOLVING && + !neigh_event_send(e->neigh, NULL)) { + spin_lock_bh(&e->lock); + if (e->state == L2T_STATE_RESOLVING && e->arpq_head) + write_l2e(adap, e, 1); + spin_unlock_bh(&e->lock); + } + } + return 0; +} +EXPORT_SYMBOL(cxgb4_l2t_send); + +/* + * Allocate a free L2T entry. Must be called with l2t_data.lock held. + */ +static struct l2t_entry *alloc_l2e(struct l2t_data *d) +{ + struct l2t_entry *end, *e, **p; + + if (!atomic_read(&d->nfree)) + return NULL; + + /* there's definitely a free entry */ + for (e = d->rover, end = &d->l2tab[L2T_SIZE]; e != end; ++e) + if (atomic_read(&e->refcnt) == 0) + goto found; + + for (e = d->l2tab; atomic_read(&e->refcnt); ++e) + ; +found: + d->rover = e + 1; + atomic_dec(&d->nfree); + + /* + * The entry we found may be an inactive entry that is + * presently in the hash table. We need to remove it. + */ + if (e->state < L2T_STATE_SWITCHING) + for (p = &d->l2tab[e->hash].first; *p; p = &(*p)->next) + if (*p == e) { + *p = e->next; + e->next = NULL; + break; + } + + e->state = L2T_STATE_UNUSED; + return e; +} + +/* + * Called when an L2T entry has no more users. + */ +static void t4_l2e_free(struct l2t_entry *e) +{ + struct l2t_data *d; + + spin_lock_bh(&e->lock); + if (atomic_read(&e->refcnt) == 0) { /* hasn't been recycled */ + if (e->neigh) { + neigh_release(e->neigh); + e->neigh = NULL; + } + } + spin_unlock_bh(&e->lock); + + d = container_of(e, struct l2t_data, l2tab[e->idx]); + atomic_inc(&d->nfree); +} + +void cxgb4_l2t_release(struct l2t_entry *e) +{ + if (atomic_dec_and_test(&e->refcnt)) + t4_l2e_free(e); +} +EXPORT_SYMBOL(cxgb4_l2t_release); + +/* + * Update an L2T entry that was previously used for the same next hop as neigh. + * Must be called with softirqs disabled. + */ +static void reuse_entry(struct l2t_entry *e, struct neighbour *neigh) +{ + unsigned int nud_state; + + spin_lock(&e->lock); /* avoid race with t4_l2t_free */ + if (neigh != e->neigh) + neigh_replace(e, neigh); + nud_state = neigh->nud_state; + if (memcmp(e->dmac, neigh->ha, sizeof(e->dmac)) || + !(nud_state & NUD_VALID)) + e->state = L2T_STATE_RESOLVING; + else if (nud_state & NUD_CONNECTED) + e->state = L2T_STATE_VALID; + else + e->state = L2T_STATE_STALE; + spin_unlock(&e->lock); +} + +struct l2t_entry *cxgb4_l2t_get(struct l2t_data *d, struct neighbour *neigh, + const struct net_device *physdev, + unsigned int priority) +{ + u8 lport; + u16 vlan; + struct l2t_entry *e; + int addr_len = neigh->tbl->key_len; + u32 *addr = (u32 *)neigh->primary_key; + int ifidx = neigh->dev->ifindex; + int hash = addr_hash(addr, addr_len, ifidx); + + if (neigh->dev->flags & IFF_LOOPBACK) + lport = netdev2pinfo(physdev)->tx_chan + 4; + else + lport = netdev2pinfo(physdev)->lport; + + if (neigh->dev->priv_flags & IFF_802_1Q_VLAN) + vlan = vlan_dev_vlan_id(neigh->dev); + else + vlan = VLAN_NONE; + + write_lock_bh(&d->lock); + for (e = d->l2tab[hash].first; e; e = e->next) + if (!addreq(e, addr) && e->ifindex == ifidx && + e->vlan == vlan && e->lport == lport) { + l2t_hold(d, e); + if (atomic_read(&e->refcnt) == 1) + reuse_entry(e, neigh); + goto done; + } + + /* Need to allocate a new entry */ + e = alloc_l2e(d); + if (e) { + spin_lock(&e->lock); /* avoid race with t4_l2t_free */ + e->state = L2T_STATE_RESOLVING; + memcpy(e->addr, addr, addr_len); + e->ifindex = ifidx; + e->hash = hash; + e->lport = lport; + e->v6 = addr_len == 16; + atomic_set(&e->refcnt, 1); + neigh_replace(e, neigh); + e->vlan = vlan; + e->next = d->l2tab[hash].first; + d->l2tab[hash].first = e; + spin_unlock(&e->lock); + } +done: + write_unlock_bh(&d->lock); + return e; +} +EXPORT_SYMBOL(cxgb4_l2t_get); + +/* + * Called when address resolution fails for an L2T entry to handle packets + * on the arpq head. If a packet specifies a failure handler it is invoked, + * otherwise the packet is sent to the device. + */ +static void handle_failed_resolution(struct adapter *adap, struct sk_buff *arpq) +{ + while (arpq) { + struct sk_buff *skb = arpq; + const struct l2t_skb_cb *cb = L2T_SKB_CB(skb); + + arpq = skb->next; + skb->next = NULL; + if (cb->arp_err_handler) + cb->arp_err_handler(cb->handle, skb); + else + t4_ofld_send(adap, skb); + } +} + +/* + * Called when the host's neighbor layer makes a change to some entry that is + * loaded into the HW L2 table. + */ +void t4_l2t_update(struct adapter *adap, struct neighbour *neigh) +{ + struct l2t_entry *e; + struct sk_buff *arpq = NULL; + struct l2t_data *d = adap->l2t; + int addr_len = neigh->tbl->key_len; + u32 *addr = (u32 *) neigh->primary_key; + int ifidx = neigh->dev->ifindex; + int hash = addr_hash(addr, addr_len, ifidx); + + read_lock_bh(&d->lock); + for (e = d->l2tab[hash].first; e; e = e->next) + if (!addreq(e, addr) && e->ifindex == ifidx) { + spin_lock(&e->lock); + if (atomic_read(&e->refcnt)) + goto found; + spin_unlock(&e->lock); + break; + } + read_unlock_bh(&d->lock); + return; + + found: + read_unlock(&d->lock); + + if (neigh != e->neigh) + neigh_replace(e, neigh); + + if (e->state == L2T_STATE_RESOLVING) { + if (neigh->nud_state & NUD_FAILED) { + arpq = e->arpq_head; + e->arpq_head = e->arpq_tail = NULL; + } else if ((neigh->nud_state & (NUD_CONNECTED | NUD_STALE)) && + e->arpq_head) { + write_l2e(adap, e, 1); + } + } else { + e->state = neigh->nud_state & NUD_CONNECTED ? + L2T_STATE_VALID : L2T_STATE_STALE; + if (memcmp(e->dmac, neigh->ha, sizeof(e->dmac))) + write_l2e(adap, e, 0); + } + + spin_unlock_bh(&e->lock); + + if (arpq) + handle_failed_resolution(adap, arpq); +} + +/* + * Allocate an L2T entry for use by a switching rule. Such entries need to be + * explicitly freed and while busy they are not on any hash chain, so normal + * address resolution updates do not see them. + */ +struct l2t_entry *t4_l2t_alloc_switching(struct l2t_data *d) +{ + struct l2t_entry *e; + + write_lock_bh(&d->lock); + e = alloc_l2e(d); + if (e) { + spin_lock(&e->lock); /* avoid race with t4_l2t_free */ + e->state = L2T_STATE_SWITCHING; + atomic_set(&e->refcnt, 1); + spin_unlock(&e->lock); + } + write_unlock_bh(&d->lock); + return e; +} + +/* + * Sets/updates the contents of a switching L2T entry that has been allocated + * with an earlier call to @t4_l2t_alloc_switching. + */ +int t4_l2t_set_switching(struct adapter *adap, struct l2t_entry *e, u16 vlan, + u8 port, u8 *eth_addr) +{ + e->vlan = vlan; + e->lport = port; + memcpy(e->dmac, eth_addr, ETH_ALEN); + return write_l2e(adap, e, 0); +} + +struct l2t_data *t4_init_l2t(void) +{ + int i; + struct l2t_data *d; + + d = t4_alloc_mem(sizeof(*d)); + if (!d) + return NULL; + + d->rover = d->l2tab; + atomic_set(&d->nfree, L2T_SIZE); + rwlock_init(&d->lock); + + for (i = 0; i < L2T_SIZE; ++i) { + d->l2tab[i].idx = i; + d->l2tab[i].state = L2T_STATE_UNUSED; + spin_lock_init(&d->l2tab[i].lock); + atomic_set(&d->l2tab[i].refcnt, 0); + } + return d; +} + +#include <linux/module.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> + +static inline void *l2t_get_idx(struct seq_file *seq, loff_t pos) +{ + struct l2t_entry *l2tab = seq->private; + + return pos >= L2T_SIZE ? NULL : &l2tab[pos]; +} + +static void *l2t_seq_start(struct seq_file *seq, loff_t *pos) +{ + return *pos ? l2t_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; +} + +static void *l2t_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + v = l2t_get_idx(seq, *pos); + if (v) + ++*pos; + return v; +} + +static void l2t_seq_stop(struct seq_file *seq, void *v) +{ +} + +static char l2e_state(const struct l2t_entry *e) +{ + switch (e->state) { + case L2T_STATE_VALID: return 'V'; + case L2T_STATE_STALE: return 'S'; + case L2T_STATE_SYNC_WRITE: return 'W'; + case L2T_STATE_RESOLVING: return e->arpq_head ? 'A' : 'R'; + case L2T_STATE_SWITCHING: return 'X'; + default: + return 'U'; + } +} + +static int l2t_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) + seq_puts(seq, " Idx IP address " + "Ethernet address VLAN/P LP State Users Port\n"); + else { + char ip[60]; + struct l2t_entry *e = v; + + spin_lock_bh(&e->lock); + if (e->state == L2T_STATE_SWITCHING) + ip[0] = '\0'; + else + sprintf(ip, e->v6 ? "%pI6c" : "%pI4", e->addr); + seq_printf(seq, "%4u %-25s %17pM %4d %u %2u %c %5u %s\n", + e->idx, ip, e->dmac, + e->vlan & VLAN_VID_MASK, vlan_prio(e), e->lport, + l2e_state(e), atomic_read(&e->refcnt), + e->neigh ? e->neigh->dev->name : ""); + spin_unlock_bh(&e->lock); + } + return 0; +} + +static const struct seq_operations l2t_seq_ops = { + .start = l2t_seq_start, + .next = l2t_seq_next, + .stop = l2t_seq_stop, + .show = l2t_seq_show +}; + +static int l2t_seq_open(struct inode *inode, struct file *file) +{ + int rc = seq_open(file, &l2t_seq_ops); + + if (!rc) { + struct adapter *adap = inode->i_private; + struct seq_file *seq = file->private_data; + + seq->private = adap->l2t->l2tab; + } + return rc; +} + +const struct file_operations t4_l2t_fops = { + .owner = THIS_MODULE, + .open = l2t_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; |