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path: root/drivers/net/cxgb4/l2t.c
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Diffstat (limited to 'drivers/net/cxgb4/l2t.c')
-rw-r--r--drivers/net/cxgb4/l2t.c624
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 00000000000..9f96724a133
--- /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,
+};
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-25 00:25:28 +0000