nfp: add control message passing capabilities to flower offloads

Previously the flower offloads never sends messages to the hardware,
and never registers a handler for receiving messages from hardware.
This patch enables the flower offloads to send control messages to
hardware when adding and removing flow rules. Additionally it
registers a control message rx handler for receiving stats updates
from hardware for each offloaded flow.

Additionally this patch adds 4 control message types; Add, modify and
delete flow, as well as flow stats. It also allows
nfp_flower_cmsg_get_data() to be used outside of cmsg.c.
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/flower/cmsg.c

@@ -36,6 +36,7 @@
 #include <linux/skbuff.h>
 #include <net/dst_metadata.h>
 
+#include "main.h"
 #include "../nfpcore/nfp_cpp.h"
 #include "../nfp_net_repr.h"
 #include "./cmsg.h"
@@ -52,7 +53,7 @@ nfp_flower_cmsg_get_hdr(struct sk_buff *skb)
 	return (struct nfp_flower_cmsg_hdr *)skb->data;
 }
 
-static struct sk_buff *
+struct sk_buff *
 nfp_flower_cmsg_alloc(struct nfp_app *app, unsigned int size,
 		      enum nfp_flower_cmsg_type_port type)
 {
@@ -143,6 +144,9 @@ void nfp_flower_cmsg_rx(struct nfp_app *app, struct sk_buff *skb)
 	case NFP_FLOWER_CMSG_TYPE_PORT_MOD:
 		nfp_flower_cmsg_portmod_rx(app, skb);
 		break;
+	case NFP_FLOWER_CMSG_TYPE_FLOW_STATS:
+		nfp_flower_rx_flow_stats(app, skb);
+		break;
 	default:
 		nfp_flower_cmsg_warn(app, "Cannot handle invalid repr control type %u\n",
 				     type);

drivers/net/ethernet/netronome/nfp/flower/cmsg.h

@@ -245,7 +245,10 @@ struct nfp_flower_cmsg_hdr {
 
 /* Types defined for port related control messages  */
 enum nfp_flower_cmsg_type_port {
+	NFP_FLOWER_CMSG_TYPE_FLOW_ADD =		0,
+	NFP_FLOWER_CMSG_TYPE_FLOW_DEL =		2,
 	NFP_FLOWER_CMSG_TYPE_PORT_MOD =		8,
+	NFP_FLOWER_CMSG_TYPE_FLOW_STATS =	15,
 	NFP_FLOWER_CMSG_TYPE_PORT_ECHO =	16,
 	NFP_FLOWER_CMSG_TYPE_MAX =		32,
 };
@@ -307,5 +310,8 @@ static inline void *nfp_flower_cmsg_get_data(struct sk_buff *skb)
 
 int nfp_flower_cmsg_portmod(struct nfp_repr *repr, bool carrier_ok);
 void nfp_flower_cmsg_rx(struct nfp_app *app, struct sk_buff *skb);
+struct sk_buff *
+nfp_flower_cmsg_alloc(struct nfp_app *app, unsigned int size,
+		      enum nfp_flower_cmsg_type_port type);
 
 #endif

drivers/net/ethernet/netronome/nfp/flower/offload.c

@@ -44,6 +44,52 @@
 #include "../nfp_net.h"
 #include "../nfp_port.h"
 
+static int
+nfp_flower_xmit_flow(struct net_device *netdev,
+		     struct nfp_fl_payload *nfp_flow, u8 mtype)
+{
+	u32 meta_len, key_len, mask_len, act_len, tot_len;
+	struct nfp_repr *priv = netdev_priv(netdev);
+	struct sk_buff *skb;
+	unsigned char *msg;
+
+	meta_len =  sizeof(struct nfp_fl_rule_metadata);
+	key_len = nfp_flow->meta.key_len;
+	mask_len = nfp_flow->meta.mask_len;
+	act_len = nfp_flow->meta.act_len;
+
+	tot_len = meta_len + key_len + mask_len + act_len;
+
+	/* Convert to long words as firmware expects
+	 * lengths in units of NFP_FL_LW_SIZ.
+	 */
+	nfp_flow->meta.key_len >>= NFP_FL_LW_SIZ;
+	nfp_flow->meta.mask_len >>= NFP_FL_LW_SIZ;
+	nfp_flow->meta.act_len >>= NFP_FL_LW_SIZ;
+
+	skb = nfp_flower_cmsg_alloc(priv->app, tot_len, mtype);
+	if (!skb)
+		return -ENOMEM;
+
+	msg = nfp_flower_cmsg_get_data(skb);
+	memcpy(msg, &nfp_flow->meta, meta_len);
+	memcpy(&msg[meta_len], nfp_flow->unmasked_data, key_len);
+	memcpy(&msg[meta_len + key_len], nfp_flow->mask_data, mask_len);
+	memcpy(&msg[meta_len + key_len + mask_len],
+	       nfp_flow->action_data, act_len);
+
+	/* Convert back to bytes as software expects
+	 * lengths in units of bytes.
+	 */
+	nfp_flow->meta.key_len <<= NFP_FL_LW_SIZ;
+	nfp_flow->meta.mask_len <<= NFP_FL_LW_SIZ;
+	nfp_flow->meta.act_len <<= NFP_FL_LW_SIZ;
+
+	nfp_ctrl_tx(priv->app->ctrl, skb);
+
+	return 0;
+}
+
 static bool nfp_flower_check_higher_than_mac(struct tc_cls_flower_offload *f)
 {
 	return dissector_uses_key(f->dissector,
@@ -228,6 +274,11 @@ nfp_flower_add_offload(struct nfp_app *app, struct net_device *netdev,
 	if (err)
 		goto err_destroy_flow;
 
+	err = nfp_flower_xmit_flow(netdev, flow_pay,
+				   NFP_FLOWER_CMSG_TYPE_FLOW_ADD);
+	if (err)
+		goto err_destroy_flow;
+
 	INIT_HLIST_NODE(&flow_pay->link);
 	flow_pay->tc_flower_cookie = flow->cookie;
 	hash_add_rcu(priv->flow_table, &flow_pay->link, flow->cookie);
@@ -270,7 +321,15 @@ nfp_flower_del_offload(struct nfp_app *app, struct net_device *netdev,
 		return -ENOENT;
 
 	err = nfp_modify_flow_metadata(app, nfp_flow);
+	if (err)
+		goto err_free_flow;
 
+	err = nfp_flower_xmit_flow(netdev, nfp_flow,
+				   NFP_FLOWER_CMSG_TYPE_FLOW_DEL);
+	if (err)
+		goto err_free_flow;
+
+err_free_flow:
 	hash_del_rcu(&nfp_flow->link);
 	kfree(nfp_flow->action_data);
 	kfree(nfp_flow->mask_data);