cxgb4: Add T4 filter support

The T4 architecture is capable of filtering ingress packets at line rate
using the rule in TCAM. If packet hits a rule in the TCAM then it can be either
dropped or passed to the receive queues based on a rule settings.

This patch adds framework for managing filters and to use T4's filter
capabilities. It constructs a Firmware Filter Work Request which writes the
filter at a specified index to get the work done. It hosts shadow copy of
ingress filter entry to check field size limitations and save memory in the
case where the filter table is large.

Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 288 insertions, 6 deletions

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index a27b4ae20f43..41537a403eef 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -175,6 +175,30 @@ enum {
 	MIN_FL_ENTRIES       = 16
 };
 
+/* Host shadow copy of ingress filter entry.  This is in host native format
+ * and doesn't match the ordering or bit order, etc. of the hardware of the
+ * firmware command.  The use of bit-field structure elements is purely to
+ * remind ourselves of the field size limitations and save memory in the case
+ * where the filter table is large.
+ */
+struct filter_entry {
+	/* Administrative fields for filter.
+	 */
+	u32 valid:1;            /* filter allocated and valid */
+	u32 locked:1;           /* filter is administratively locked */
+
+	u32 pending:1;          /* filter action is pending firmware reply */
+	u32 smtidx:8;           /* Source MAC Table index for smac */
+	struct l2t_entry *l2t;  /* Layer Two Table entry for dmac */
+
+	/* The filter itself.  Most of this is a straight copy of information
+	 * provided by the extended ioctl().  Some fields are translated to
+	 * internal forms -- for instance the Ingress Queue ID passed in from
+	 * the ioctl() is translated into the Absolute Ingress Queue ID.
+	 */
+	struct ch_filter_specification fs;
+};
+
 #define DFLT_MSG_ENABLE (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK | \
 			 NETIF_MSG_TIMER | NETIF_MSG_IFDOWN | NETIF_MSG_IFUP |\
 			 NETIF_MSG_RX_ERR | NETIF_MSG_TX_ERR)
@@ -325,6 +349,9 @@ enum {
 
 static unsigned int tp_vlan_pri_map = TP_VLAN_PRI_MAP_DEFAULT;
 
+module_param(tp_vlan_pri_map, uint, 0644);
+MODULE_PARM_DESC(tp_vlan_pri_map, "global compressed filter configuration");
+
 static struct dentry *cxgb4_debugfs_root;
 
 static LIST_HEAD(adapter_list);
@@ -506,8 +533,67 @@ static int link_start(struct net_device *dev)
 	return ret;
 }
 
-/*
- * Response queue handler for the FW event queue.
+/* Clear a filter and release any of its resources that we own.  This also
+ * clears the filter's "pending" status.
+ */
+static void clear_filter(struct adapter *adap, struct filter_entry *f)
+{
+	/* If the new or old filter have loopback rewriteing rules then we'll
+	 * need to free any existing Layer Two Table (L2T) entries of the old
+	 * filter rule.  The firmware will handle freeing up any Source MAC
+	 * Table (SMT) entries used for rewriting Source MAC Addresses in
+	 * loopback rules.
+	 */
+	if (f->l2t)
+		cxgb4_l2t_release(f->l2t);
+
+	/* The zeroing of the filter rule below clears the filter valid,
+	 * pending, locked flags, l2t pointer, etc. so it's all we need for
+	 * this operation.
+	 */
+	memset(f, 0, sizeof(*f));
+}
+
+/* Handle a filter write/deletion reply.
+ */
+static void filter_rpl(struct adapter *adap, const struct cpl_set_tcb_rpl *rpl)
+{
+	unsigned int idx = GET_TID(rpl);
+	unsigned int nidx = idx - adap->tids.ftid_base;
+	unsigned int ret;
+	struct filter_entry *f;
+
+	if (idx >= adap->tids.ftid_base && nidx <
+	   (adap->tids.nftids + adap->tids.nsftids)) {
+		idx = nidx;
+		ret = GET_TCB_COOKIE(rpl->cookie);
+		f = &adap->tids.ftid_tab[idx];
+
+		if (ret == FW_FILTER_WR_FLT_DELETED) {
+			/* Clear the filter when we get confirmation from the
+			 * hardware that the filter has been deleted.
+			 */
+			clear_filter(adap, f);
+		} else if (ret == FW_FILTER_WR_SMT_TBL_FULL) {
+			dev_err(adap->pdev_dev, "filter %u setup failed due to full SMT\n",
+				idx);
+			clear_filter(adap, f);
+		} else if (ret == FW_FILTER_WR_FLT_ADDED) {
+			f->smtidx = (be64_to_cpu(rpl->oldval) >> 24) & 0xff;
+			f->pending = 0;  /* asynchronous setup completed */
+			f->valid = 1;
+		} else {
+			/* Something went wrong.  Issue a warning about the
+			 * problem and clear everything out.
+			 */
+			dev_err(adap->pdev_dev, "filter %u setup failed with error %u\n",
+				idx, ret);
+			clear_filter(adap, f);
+		}
+	}
+}
+
+/* Response queue handler for the FW event queue.
  */
 static int fwevtq_handler(struct sge_rspq *q, const __be64 *rsp,
 			  const struct pkt_gl *gl)
@@ -542,6 +628,10 @@ static int fwevtq_handler(struct sge_rspq *q, const __be64 *rsp,
 		const struct cpl_l2t_write_rpl *p = (void *)rsp;
 
 		do_l2t_write_rpl(q->adap, p);
+	} else if (opcode == CPL_SET_TCB_RPL) {
+		const struct cpl_set_tcb_rpl *p = (void *)rsp;
+
+		filter_rpl(q->adap, p);
 	} else
 		dev_err(q->adap->pdev_dev,
 			"unexpected CPL %#x on FW event queue\n", opcode);
@@ -983,6 +1073,148 @@ static void t4_free_mem(void *addr)
 		kfree(addr);
 }
 
+/* Send a Work Request to write the filter at a specified index.  We construct
+ * a Firmware Filter Work Request to have the work done and put the indicated
+ * filter into "pending" mode which will prevent any further actions against
+ * it till we get a reply from the firmware on the completion status of the
+ * request.
+ */
+static int set_filter_wr(struct adapter *adapter, int fidx)
+{
+	struct filter_entry *f = &adapter->tids.ftid_tab[fidx];
+	struct sk_buff *skb;
+	struct fw_filter_wr *fwr;
+	unsigned int ftid;
+
+	/* If the new filter requires loopback Destination MAC and/or VLAN
+	 * rewriting then we need to allocate a Layer 2 Table (L2T) entry for
+	 * the filter.
+	 */
+	if (f->fs.newdmac || f->fs.newvlan) {
+		/* allocate L2T entry for new filter */
+		f->l2t = t4_l2t_alloc_switching(adapter->l2t);
+		if (f->l2t == NULL)
+			return -EAGAIN;
+		if (t4_l2t_set_switching(adapter, f->l2t, f->fs.vlan,
+					f->fs.eport, f->fs.dmac)) {
+			cxgb4_l2t_release(f->l2t);
+			f->l2t = NULL;
+			return -ENOMEM;
+		}
+	}
+
+	ftid = adapter->tids.ftid_base + fidx;
+
+	skb = alloc_skb(sizeof(*fwr), GFP_KERNEL | __GFP_NOFAIL);
+	fwr = (struct fw_filter_wr *)__skb_put(skb, sizeof(*fwr));
+	memset(fwr, 0, sizeof(*fwr));
+
+	/* It would be nice to put most of the following in t4_hw.c but most
+	 * of the work is translating the cxgbtool ch_filter_specification
+	 * into the Work Request and the definition of that structure is
+	 * currently in cxgbtool.h which isn't appropriate to pull into the
+	 * common code.  We may eventually try to come up with a more neutral
+	 * filter specification structure but for now it's easiest to simply
+	 * put this fairly direct code in line ...
+	 */
+	fwr->op_pkd = htonl(FW_WR_OP(FW_FILTER_WR));
+	fwr->len16_pkd = htonl(FW_WR_LEN16(sizeof(*fwr)/16));
+	fwr->tid_to_iq =
+		htonl(V_FW_FILTER_WR_TID(ftid) |
+		      V_FW_FILTER_WR_RQTYPE(f->fs.type) |
+		      V_FW_FILTER_WR_NOREPLY(0) |
+		      V_FW_FILTER_WR_IQ(f->fs.iq));
+	fwr->del_filter_to_l2tix =
+		htonl(V_FW_FILTER_WR_RPTTID(f->fs.rpttid) |
+		      V_FW_FILTER_WR_DROP(f->fs.action == FILTER_DROP) |
+		      V_FW_FILTER_WR_DIRSTEER(f->fs.dirsteer) |
+		      V_FW_FILTER_WR_MASKHASH(f->fs.maskhash) |
+		      V_FW_FILTER_WR_DIRSTEERHASH(f->fs.dirsteerhash) |
+		      V_FW_FILTER_WR_LPBK(f->fs.action == FILTER_SWITCH) |
+		      V_FW_FILTER_WR_DMAC(f->fs.newdmac) |
+		      V_FW_FILTER_WR_SMAC(f->fs.newsmac) |
+		      V_FW_FILTER_WR_INSVLAN(f->fs.newvlan == VLAN_INSERT ||
+					     f->fs.newvlan == VLAN_REWRITE) |
+		      V_FW_FILTER_WR_RMVLAN(f->fs.newvlan == VLAN_REMOVE ||
+					    f->fs.newvlan == VLAN_REWRITE) |
+		      V_FW_FILTER_WR_HITCNTS(f->fs.hitcnts) |
+		      V_FW_FILTER_WR_TXCHAN(f->fs.eport) |
+		      V_FW_FILTER_WR_PRIO(f->fs.prio) |
+		      V_FW_FILTER_WR_L2TIX(f->l2t ? f->l2t->idx : 0));
+	fwr->ethtype = htons(f->fs.val.ethtype);
+	fwr->ethtypem = htons(f->fs.mask.ethtype);
+	fwr->frag_to_ovlan_vldm =
+		(V_FW_FILTER_WR_FRAG(f->fs.val.frag) |
+		 V_FW_FILTER_WR_FRAGM(f->fs.mask.frag) |
+		 V_FW_FILTER_WR_IVLAN_VLD(f->fs.val.ivlan_vld) |
+		 V_FW_FILTER_WR_OVLAN_VLD(f->fs.val.ovlan_vld) |
+		 V_FW_FILTER_WR_IVLAN_VLDM(f->fs.mask.ivlan_vld) |
+		 V_FW_FILTER_WR_OVLAN_VLDM(f->fs.mask.ovlan_vld));
+	fwr->smac_sel = 0;
+	fwr->rx_chan_rx_rpl_iq =
+		htons(V_FW_FILTER_WR_RX_CHAN(0) |
+		      V_FW_FILTER_WR_RX_RPL_IQ(adapter->sge.fw_evtq.abs_id));
+	fwr->maci_to_matchtypem =
+		htonl(V_FW_FILTER_WR_MACI(f->fs.val.macidx) |
+		      V_FW_FILTER_WR_MACIM(f->fs.mask.macidx) |
+		      V_FW_FILTER_WR_FCOE(f->fs.val.fcoe) |
+		      V_FW_FILTER_WR_FCOEM(f->fs.mask.fcoe) |
+		      V_FW_FILTER_WR_PORT(f->fs.val.iport) |
+		      V_FW_FILTER_WR_PORTM(f->fs.mask.iport) |
+		      V_FW_FILTER_WR_MATCHTYPE(f->fs.val.matchtype) |
+		      V_FW_FILTER_WR_MATCHTYPEM(f->fs.mask.matchtype));
+	fwr->ptcl = f->fs.val.proto;
+	fwr->ptclm = f->fs.mask.proto;
+	fwr->ttyp = f->fs.val.tos;
+	fwr->ttypm = f->fs.mask.tos;
+	fwr->ivlan = htons(f->fs.val.ivlan);
+	fwr->ivlanm = htons(f->fs.mask.ivlan);
+	fwr->ovlan = htons(f->fs.val.ovlan);
+	fwr->ovlanm = htons(f->fs.mask.ovlan);
+	memcpy(fwr->lip, f->fs.val.lip, sizeof(fwr->lip));
+	memcpy(fwr->lipm, f->fs.mask.lip, sizeof(fwr->lipm));
+	memcpy(fwr->fip, f->fs.val.fip, sizeof(fwr->fip));
+	memcpy(fwr->fipm, f->fs.mask.fip, sizeof(fwr->fipm));
+	fwr->lp = htons(f->fs.val.lport);
+	fwr->lpm = htons(f->fs.mask.lport);
+	fwr->fp = htons(f->fs.val.fport);
+	fwr->fpm = htons(f->fs.mask.fport);
+	if (f->fs.newsmac)
+		memcpy(fwr->sma, f->fs.smac, sizeof(fwr->sma));
+
+	/* Mark the filter as "pending" and ship off the Filter Work Request.
+	 * When we get the Work Request Reply we'll clear the pending status.
+	 */
+	f->pending = 1;
+	set_wr_txq(skb, CPL_PRIORITY_CONTROL, f->fs.val.iport & 0x3);
+	t4_ofld_send(adapter, skb);
+	return 0;
+}
+
+/* Delete the filter at a specified index.
+ */
+static int del_filter_wr(struct adapter *adapter, int fidx)
+{
+	struct filter_entry *f = &adapter->tids.ftid_tab[fidx];
+	struct sk_buff *skb;
+	struct fw_filter_wr *fwr;
+	unsigned int len, ftid;
+
+	len = sizeof(*fwr);
+	ftid = adapter->tids.ftid_base + fidx;
+
+	skb = alloc_skb(len, GFP_KERNEL | __GFP_NOFAIL);
+	fwr = (struct fw_filter_wr *)__skb_put(skb, len);
+	t4_mk_filtdelwr(ftid, fwr, adapter->sge.fw_evtq.abs_id);
+
+	/* Mark the filter as "pending" and ship off the Filter Work Request.
+	 * When we get the Work Request Reply we'll clear the pending status.
+	 */
+	f->pending = 1;
+	t4_mgmt_tx(adapter, skb);
+	return 0;
+}
+
 static inline int is_offload(const struct adapter *adap)
 {
 	return adap->params.offload;
@@ -2195,7 +2427,7 @@ int cxgb4_alloc_atid(struct tid_info *t, void *data)
 	if (t->afree) {
 		union aopen_entry *p = t->afree;
 
-		atid = p - t->atid_tab;
+		atid = (p - t->atid_tab) + t->atid_base;
 		t->afree = p->next;
 		p->data = data;
 		t->atids_in_use++;
@@ -2210,7 +2442,7 @@ EXPORT_SYMBOL(cxgb4_alloc_atid);
  */
 void cxgb4_free_atid(struct tid_info *t, unsigned int atid)
 {
-	union aopen_entry *p = &t->atid_tab[atid];
+	union aopen_entry *p = &t->atid_tab[atid - t->atid_base];
 
 	spin_lock_bh(&t->atid_lock);
 	p->next = t->afree;
@@ -2362,11 +2594,16 @@ EXPORT_SYMBOL(cxgb4_remove_tid);
 static int tid_init(struct tid_info *t)
 {
 	size_t size;
+	unsigned int stid_bmap_size;
 	unsigned int natids = t->natids;
 
-	size = t->ntids * sizeof(*t->tid_tab) + natids * sizeof(*t->atid_tab) +
+	stid_bmap_size = BITS_TO_LONGS(t->nstids);
+	size = t->ntids * sizeof(*t->tid_tab) +
+	       natids * sizeof(*t->atid_tab) +
 	       t->nstids * sizeof(*t->stid_tab) +
-	       BITS_TO_LONGS(t->nstids) * sizeof(long);
+	       stid_bmap_size * sizeof(long) +
+	       t->nftids * sizeof(*t->ftid_tab);
+
 	t->tid_tab = t4_alloc_mem(size);
 	if (!t->tid_tab)
 		return -ENOMEM;
@@ -2374,6 +2611,7 @@ static int tid_init(struct tid_info *t)
 	t->atid_tab = (union aopen_entry *)&t->tid_tab[t->ntids];
 	t->stid_tab = (struct serv_entry *)&t->atid_tab[natids];
 	t->stid_bmap = (unsigned long *)&t->stid_tab[t->nstids];
+	t->ftid_tab = (struct filter_entry *)&t->stid_bmap[stid_bmap_size];
 	spin_lock_init(&t->stid_lock);
 	spin_lock_init(&t->atid_lock);
 
@@ -2999,6 +3237,40 @@ static int cxgb_close(struct net_device *dev)
 	return t4_enable_vi(adapter, adapter->fn, pi->viid, false, false);
 }
 
+/* Return an error number if the indicated filter isn't writable ...
+ */
+static int writable_filter(struct filter_entry *f)
+{
+	if (f->locked)
+		return -EPERM;
+	if (f->pending)
+		return -EBUSY;
+
+	return 0;
+}
+
+/* Delete the filter at the specified index (if valid).  The checks for all
+ * the common problems with doing this like the filter being locked, currently
+ * pending in another operation, etc.
+ */
+static int delete_filter(struct adapter *adapter, unsigned int fidx)
+{
+	struct filter_entry *f;
+	int ret;
+
+	if (fidx >= adapter->tids.nftids)
+		return -EINVAL;
+
+	f = &adapter->tids.ftid_tab[fidx];
+	ret = writable_filter(f);
+	if (ret)
+		return ret;
+	if (f->valid)
+		return del_filter_wr(adapter, fidx);
+
+	return 0;
+}
+
 static struct rtnl_link_stats64 *cxgb_get_stats(struct net_device *dev,
 						struct rtnl_link_stats64 *ns)
 {
@@ -4661,6 +4933,16 @@ static void remove_one(struct pci_dev *pdev)
 		if (adapter->debugfs_root)
 			debugfs_remove_recursive(adapter->debugfs_root);
 
+		/* If we allocated filters, free up state associated with any
+		 * valid filters ...
+		 */
+		if (adapter->tids.ftid_tab) {
+			struct filter_entry *f = &adapter->tids.ftid_tab[0];
+			for (i = 0; i < adapter->tids.nftids; i++, f++)
+				if (f->valid)
+					clear_filter(adapter, f);
+		}
+
 		if (adapter->flags & FULL_INIT_DONE)
 			cxgb_down(adapter);