cxgb4: add basic tc flower offload support

Add support to add/remove flows for offload.  Following match
and action are supported for offloading a flow:

Match: ether-protocol, IPv4/IPv6 addresses, L4 ports (TCP/UDP)
Action: drop, redirect to another port on the device.

The qualifying flows can have accompanying mask information.
Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -905,6 +905,9 @@ struct adapter {
 	/* TC u32 offload */
 	struct cxgb4_tc_u32_table *tc_u32;
 	struct chcr_stats_debug chcr_stats;
+
+	/* TC flower offload */
+	DECLARE_HASHTABLE(flower_anymatch_tbl, 9);
 };
 
 /* Support for "sched-class" command to allow a TX Scheduling Class to be

drivers/net/ethernet/chelsio/cxgb4/cxgb4_filter.c

@@ -148,6 +148,30 @@ static int get_filter_steerq(struct net_device *dev,
 	return iq;
 }
 
+int cxgb4_get_free_ftid(struct net_device *dev, int family)
+{
+	struct adapter *adap = netdev2adap(dev);
+	struct tid_info *t = &adap->tids;
+	int ftid;
+
+	spin_lock_bh(&t->ftid_lock);
+	if (family == PF_INET) {
+		ftid = find_first_zero_bit(t->ftid_bmap, t->nftids);
+		if (ftid >= t->nftids)
+			ftid = -1;
+	} else {
+		ftid = bitmap_find_free_region(t->ftid_bmap, t->nftids, 2);
+		if (ftid < 0)
+			goto out_unlock;
+
+		/* this is only a lookup, keep the found region unallocated */
+		bitmap_release_region(t->ftid_bmap, ftid, 2);
+	}
+out_unlock:
+	spin_unlock_bh(&t->ftid_lock);
+	return ftid;
+}
+
 static int cxgb4_set_ftid(struct tid_info *t, int fidx, int family)
 {
 	spin_lock_bh(&t->ftid_lock);

drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c

@@ -5105,6 +5105,8 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		if (!adapter->tc_u32)
 			dev_warn(&pdev->dev,
 				 "could not offload tc u32, continuing\n");
+
+		cxgb4_init_tc_flower(adapter);
 	}
 
 	if (is_offload(adapter)) {

drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.c

@@ -38,16 +38,287 @@
 #include "cxgb4.h"
 #include "cxgb4_tc_flower.h"
 
+static struct ch_tc_flower_entry *allocate_flower_entry(void)
+{
+	struct ch_tc_flower_entry *new = kzalloc(sizeof(*new), GFP_KERNEL);
+	return new;
+}
+
+/* Must be called with either RTNL or rcu_read_lock */
+static struct ch_tc_flower_entry *ch_flower_lookup(struct adapter *adap,
+						   unsigned long flower_cookie)
+{
+	struct ch_tc_flower_entry *flower_entry;
+
+	hash_for_each_possible_rcu(adap->flower_anymatch_tbl, flower_entry,
+				   link, flower_cookie)
+		if (flower_entry->tc_flower_cookie == flower_cookie)
+			return flower_entry;
+	return NULL;
+}
+
+static void cxgb4_process_flow_match(struct net_device *dev,
+				     struct tc_cls_flower_offload *cls,
+				     struct ch_filter_specification *fs)
+{
+	u16 addr_type = 0;
+
+	if (dissector_uses_key(cls->dissector, FLOW_DISSECTOR_KEY_CONTROL)) {
+		struct flow_dissector_key_control *key =
+			skb_flow_dissector_target(cls->dissector,
+						  FLOW_DISSECTOR_KEY_CONTROL,
+						  cls->key);
+
+		addr_type = key->addr_type;
+	}
+
+	if (dissector_uses_key(cls->dissector, FLOW_DISSECTOR_KEY_BASIC)) {
+		struct flow_dissector_key_basic *key =
+			skb_flow_dissector_target(cls->dissector,
+						  FLOW_DISSECTOR_KEY_BASIC,
+						  cls->key);
+		struct flow_dissector_key_basic *mask =
+			skb_flow_dissector_target(cls->dissector,
+						  FLOW_DISSECTOR_KEY_BASIC,
+						  cls->mask);
+		u16 ethtype_key = ntohs(key->n_proto);
+		u16 ethtype_mask = ntohs(mask->n_proto);
+
+		if (ethtype_key == ETH_P_ALL) {
+			ethtype_key = 0;
+			ethtype_mask = 0;
+		}
+
+		fs->val.ethtype = ethtype_key;
+		fs->mask.ethtype = ethtype_mask;
+		fs->val.proto = key->ip_proto;
+		fs->mask.proto = mask->ip_proto;
+	}
+
+	if (addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
+		struct flow_dissector_key_ipv4_addrs *key =
+			skb_flow_dissector_target(cls->dissector,
+						  FLOW_DISSECTOR_KEY_IPV4_ADDRS,
+						  cls->key);
+		struct flow_dissector_key_ipv4_addrs *mask =
+			skb_flow_dissector_target(cls->dissector,
+						  FLOW_DISSECTOR_KEY_IPV4_ADDRS,
+						  cls->mask);
+		fs->type = 0;
+		memcpy(&fs->val.lip[0], &key->dst, sizeof(key->dst));
+		memcpy(&fs->val.fip[0], &key->src, sizeof(key->src));
+		memcpy(&fs->mask.lip[0], &mask->dst, sizeof(mask->dst));
+		memcpy(&fs->mask.fip[0], &mask->src, sizeof(mask->src));
+	}
+
+	if (addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
+		struct flow_dissector_key_ipv6_addrs *key =
+			skb_flow_dissector_target(cls->dissector,
+						  FLOW_DISSECTOR_KEY_IPV6_ADDRS,
+						  cls->key);
+		struct flow_dissector_key_ipv6_addrs *mask =
+			skb_flow_dissector_target(cls->dissector,
+						  FLOW_DISSECTOR_KEY_IPV6_ADDRS,
+						  cls->mask);
+
+		fs->type = 1;
+		memcpy(&fs->val.lip[0], key->dst.s6_addr, sizeof(key->dst));
+		memcpy(&fs->val.fip[0], key->src.s6_addr, sizeof(key->src));
+		memcpy(&fs->mask.lip[0], mask->dst.s6_addr, sizeof(mask->dst));
+		memcpy(&fs->mask.fip[0], mask->src.s6_addr, sizeof(mask->src));
+	}
+
+	if (dissector_uses_key(cls->dissector, FLOW_DISSECTOR_KEY_PORTS)) {
+		struct flow_dissector_key_ports *key, *mask;
+
+		key = skb_flow_dissector_target(cls->dissector,
+						FLOW_DISSECTOR_KEY_PORTS,
+						cls->key);
+		mask = skb_flow_dissector_target(cls->dissector,
+						 FLOW_DISSECTOR_KEY_PORTS,
+						 cls->mask);
+		fs->val.lport = cpu_to_be16(key->dst);
+		fs->mask.lport = cpu_to_be16(mask->dst);
+		fs->val.fport = cpu_to_be16(key->src);
+		fs->mask.fport = cpu_to_be16(mask->src);
+	}
+
+	/* Match only packets coming from the ingress port where this
+	 * filter will be created.
+	 */
+	fs->val.iport = netdev2pinfo(dev)->port_id;
+	fs->mask.iport = ~0;
+}
+
+static int cxgb4_validate_flow_match(struct net_device *dev,
+				     struct tc_cls_flower_offload *cls)
+{
+	if (cls->dissector->used_keys &
+	    ~(BIT(FLOW_DISSECTOR_KEY_CONTROL) |
+	      BIT(FLOW_DISSECTOR_KEY_BASIC) |
+	      BIT(FLOW_DISSECTOR_KEY_IPV4_ADDRS) |
+	      BIT(FLOW_DISSECTOR_KEY_IPV6_ADDRS) |
+	      BIT(FLOW_DISSECTOR_KEY_PORTS))) {
+		netdev_warn(dev, "Unsupported key used: 0x%x\n",
+			    cls->dissector->used_keys);
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static void cxgb4_process_flow_actions(struct net_device *in,
+				       struct tc_cls_flower_offload *cls,
+				       struct ch_filter_specification *fs)
+{
+	const struct tc_action *a;
+	LIST_HEAD(actions);
+
+	tcf_exts_to_list(cls->exts, &actions);
+	list_for_each_entry(a, &actions, list) {
+		if (is_tcf_gact_shot(a)) {
+			fs->action = FILTER_DROP;
+		} else if (is_tcf_mirred_egress_redirect(a)) {
+			int ifindex = tcf_mirred_ifindex(a);
+			struct net_device *out = __dev_get_by_index(dev_net(in),
+								    ifindex);
+			struct port_info *pi = netdev_priv(out);
+
+			fs->action = FILTER_SWITCH;
+			fs->eport = pi->port_id;
+		}
+	}
+}
+
+static int cxgb4_validate_flow_actions(struct net_device *dev,
+				       struct tc_cls_flower_offload *cls)
+{
+	const struct tc_action *a;
+	LIST_HEAD(actions);
+
+	tcf_exts_to_list(cls->exts, &actions);
+	list_for_each_entry(a, &actions, list) {
+		if (is_tcf_gact_shot(a)) {
+			/* Do nothing */
+		} else if (is_tcf_mirred_egress_redirect(a)) {
+			struct adapter *adap = netdev2adap(dev);
+			struct net_device *n_dev;
+			unsigned int i, ifindex;
+			bool found = false;
+
+			ifindex = tcf_mirred_ifindex(a);
+			for_each_port(adap, i) {
+				n_dev = adap->port[i];
+				if (ifindex == n_dev->ifindex) {
+					found = true;
+					break;
+				}
+			}
+
+			/* If interface doesn't belong to our hw, then
+			 * the provided output port is not valid
+			 */
+			if (!found) {
+				netdev_err(dev, "%s: Out port invalid\n",
+					   __func__);
+				return -EINVAL;
+			}
+		} else {
+			netdev_err(dev, "%s: Unsupported action\n", __func__);
+			return -EOPNOTSUPP;
+		}
+	}
+	return 0;
+}
+
 int cxgb4_tc_flower_replace(struct net_device *dev,
 			    struct tc_cls_flower_offload *cls)
 {
+	struct adapter *adap = netdev2adap(dev);
+	struct ch_tc_flower_entry *ch_flower;
+	struct ch_filter_specification *fs;
+	struct filter_ctx ctx;
+	int fidx;
+	int ret;
+
+	if (cxgb4_validate_flow_actions(dev, cls))
 		return -EOPNOTSUPP;
+
+	if (cxgb4_validate_flow_match(dev, cls))
+		return -EOPNOTSUPP;
+
+	ch_flower = allocate_flower_entry();
+	if (!ch_flower) {
+		netdev_err(dev, "%s: ch_flower alloc failed.\n", __func__);
+		return -ENOMEM;
+	}
+
+	fs = &ch_flower->fs;
+	fs->hitcnts = 1;
+	cxgb4_process_flow_actions(dev, cls, fs);
+	cxgb4_process_flow_match(dev, cls, fs);
+
+	fidx = cxgb4_get_free_ftid(dev, fs->type ? PF_INET6 : PF_INET);
+	if (fidx < 0) {
+		netdev_err(dev, "%s: No fidx for offload.\n", __func__);
+		ret = -ENOMEM;
+		goto free_entry;
+	}
+
+	init_completion(&ctx.completion);
+	ret = __cxgb4_set_filter(dev, fidx, fs, &ctx);
+	if (ret) {
+		netdev_err(dev, "%s: filter creation err %d\n",
+			   __func__, ret);
+		goto free_entry;
+	}
+
+	/* Wait for reply */
+	ret = wait_for_completion_timeout(&ctx.completion, 10 * HZ);
+	if (!ret) {
+		ret = -ETIMEDOUT;
+		goto free_entry;
+	}
+
+	ret = ctx.result;
+	/* Check if hw returned error for filter creation */
+	if (ret) {
+		netdev_err(dev, "%s: filter creation err %d\n",
+			   __func__, ret);
+		goto free_entry;
+	}
+
+	INIT_HLIST_NODE(&ch_flower->link);
+	ch_flower->tc_flower_cookie = cls->cookie;
+	ch_flower->filter_id = ctx.tid;
+	hash_add_rcu(adap->flower_anymatch_tbl, &ch_flower->link, cls->cookie);
+
+	return ret;
+
+free_entry:
+	kfree(ch_flower);
+	return ret;
 }
 
 int cxgb4_tc_flower_destroy(struct net_device *dev,
 			    struct tc_cls_flower_offload *cls)
 {
-	return -EOPNOTSUPP;
+	struct adapter *adap = netdev2adap(dev);
+	struct ch_tc_flower_entry *ch_flower;
+	int ret;
+
+	ch_flower = ch_flower_lookup(adap, cls->cookie);
+	if (!ch_flower)
+		return -ENOENT;
+
+	ret = cxgb4_del_filter(dev, ch_flower->filter_id);
+	if (ret)
+		goto err;
+
+	hash_del_rcu(&ch_flower->link);
+	kfree_rcu(ch_flower, rcu);
+
+err:
+	return ret;
 }
 
 int cxgb4_tc_flower_stats(struct net_device *dev,
@@ -55,3 +326,8 @@ int cxgb4_tc_flower_stats(struct net_device *dev,
 {
 	return -EOPNOTSUPP;
 }
+
+void cxgb4_init_tc_flower(struct adapter *adap)
+{
+	hash_init(adap->flower_anymatch_tbl);
+}

drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_flower.h

@@ -37,10 +37,27 @@
 
 #include <net/pkt_cls.h>
 
+struct ch_tc_flower_stats {
+	u64 packet_count;
+	u64 byte_count;
+	u64 last_used;
+};
+
+struct ch_tc_flower_entry {
+	struct ch_filter_specification fs;
+	struct ch_tc_flower_stats stats;
+	unsigned long tc_flower_cookie;
+	struct hlist_node link;
+	struct rcu_head rcu;
+	u32 filter_id;
+};
+
 int cxgb4_tc_flower_replace(struct net_device *dev,
 			    struct tc_cls_flower_offload *cls);
 int cxgb4_tc_flower_destroy(struct net_device *dev,
 			    struct tc_cls_flower_offload *cls);
 int cxgb4_tc_flower_stats(struct net_device *dev,
 			  struct tc_cls_flower_offload *cls);
+
+void cxgb4_init_tc_flower(struct adapter *adap);
 #endif /* __CXGB4_TC_FLOWER_H */

drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h

@@ -212,6 +212,7 @@ struct filter_ctx {
 
 struct ch_filter_specification;
 
+int cxgb4_get_free_ftid(struct net_device *dev, int family);
 int __cxgb4_set_filter(struct net_device *dev, int filter_id,
 		       struct ch_filter_specification *fs,
 		       struct filter_ctx *ctx);