octeontx2-af: Support ESP/AH RSS hashing

Support SPI and sequence number fields of
ESP/AH header to be hashed for RSS. By default
ESP/AH fields are not considered for RSS and
needs to be set explicitly as below:
ethtool -U eth0 rx-flow-hash esp4 sdfn
or
ethtool -U eth0 rx-flow-hash ah4 sdfn
or
ethtool -U eth0 rx-flow-hash esp6 sdfn
or
ethtool -U eth0 rx-flow-hash ah6 sdfn

To disable hashing of ESP fields:
ethtool -U eth0 rx-flow-hash esp4 sd
or
ethtool -U eth0 rx-flow-hash ah4 sd
or
ethtool -U eth0 rx-flow-hash esp6 sd
or
ethtool -U eth0 rx-flow-hash ah6 sd
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Link: https://lore.kernel.org/r/1611378552-13288-1-git-send-email-sundeep.lkml@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/marvell/octeontx2/af/mbox.h

@@ -717,6 +717,8 @@ struct nix_rss_flowkey_cfg {
 #define NIX_FLOW_KEY_TYPE_INNR_ETH_DMAC BIT(17)
 #define NIX_FLOW_KEY_TYPE_VLAN		BIT(20)
 #define NIX_FLOW_KEY_TYPE_IPV4_PROTO	BIT(21)
+#define NIX_FLOW_KEY_TYPE_AH		BIT(22)
+#define NIX_FLOW_KEY_TYPE_ESP		BIT(23)
 	u32	flowkey_cfg; /* Flowkey types selected */
 	u8	group;       /* RSS context or group */
 };

drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c

@@ -2580,6 +2580,7 @@ static int set_flowkey_fields(struct nix_rx_flowkey_alg *alg, u32 flow_cfg)
 	struct nix_rx_flowkey_alg *field;
 	struct nix_rx_flowkey_alg tmp;
 	u32 key_type, valid_key;
+	int l4_key_offset;
 
 	if (!alg)
 		return -EINVAL;
@@ -2712,6 +2713,12 @@ static int set_flowkey_fields(struct nix_rx_flowkey_alg *alg, u32 flow_cfg)
 				field_marker = false;
 				keyoff_marker = false;
 			}
+
+			/* TCP/UDP/SCTP and ESP/AH falls at same offset so
+			 * remember the TCP key offset of 40 byte hash key.
+			 */
+			if (key_type == NIX_FLOW_KEY_TYPE_TCP)
+				l4_key_offset = key_off;
 			break;
 		case NIX_FLOW_KEY_TYPE_NVGRE:
 			field->lid = NPC_LID_LD;
@@ -2783,11 +2790,31 @@ static int set_flowkey_fields(struct nix_rx_flowkey_alg *alg, u32 flow_cfg)
 			field->ltype_mask = 0xF;
 			field->fn_mask = 1; /* Mask out the first nibble */
 			break;
+		case NIX_FLOW_KEY_TYPE_AH:
+		case NIX_FLOW_KEY_TYPE_ESP:
+			field->hdr_offset = 0;
+			field->bytesm1 = 7; /* SPI + sequence number */
+			field->ltype_mask = 0xF;
+			field->lid = NPC_LID_LE;
+			field->ltype_match = NPC_LT_LE_ESP;
+			if (key_type == NIX_FLOW_KEY_TYPE_AH) {
+				field->lid = NPC_LID_LD;
+				field->ltype_match = NPC_LT_LD_AH;
+				field->hdr_offset = 4;
+				keyoff_marker = false;
+			}
+			break;
 		}
 		field->ena = 1;
 
 		/* Found a valid flow key type */
 		if (valid_key) {
+			/* Use the key offset of TCP/UDP/SCTP fields
+			 * for ESP/AH fields.
+			 */
+			if (key_type == NIX_FLOW_KEY_TYPE_ESP ||
+			    key_type == NIX_FLOW_KEY_TYPE_AH)
+				key_off = l4_key_offset;
 			field->key_offset = key_off;
 			memcpy(&alg[nr_field], field, sizeof(*field));
 			max_key_off = max(max_key_off, field->bytesm1 + 1);

drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c

@@ -448,10 +448,14 @@ static int otx2_get_rss_hash_opts(struct otx2_nic *pfvf,
 			nfc->data |= RXH_L4_B_0_1 | RXH_L4_B_2_3;
 		break;
 	case AH_ESP_V4_FLOW:
+	case AH_ESP_V6_FLOW:
+		if (rss->flowkey_cfg & NIX_FLOW_KEY_TYPE_ESP)
+			nfc->data |= RXH_L4_B_0_1 | RXH_L4_B_2_3;
+		break;
 	case AH_V4_FLOW:
 	case ESP_V4_FLOW:
 	case IPV4_FLOW:
-	case AH_ESP_V6_FLOW:
+		break;
 	case AH_V6_FLOW:
 	case ESP_V6_FLOW:
 	case IPV6_FLOW:
@@ -459,6 +463,7 @@ static int otx2_get_rss_hash_opts(struct otx2_nic *pfvf,
 	default:
 		return -EINVAL;
 	}
+
 	return 0;
 }
 
@@ -527,6 +532,36 @@ static int otx2_set_rss_hash_opts(struct otx2_nic *pfvf,
 			return -EINVAL;
 		}
 		break;
+	case AH_ESP_V4_FLOW:
+	case AH_ESP_V6_FLOW:
+		switch (nfc->data & rxh_l4) {
+		case 0:
+			rss_cfg &= ~(NIX_FLOW_KEY_TYPE_ESP |
+				     NIX_FLOW_KEY_TYPE_AH);
+			rss_cfg |= NIX_FLOW_KEY_TYPE_VLAN |
+				   NIX_FLOW_KEY_TYPE_IPV4_PROTO;
+			break;
+		case (RXH_L4_B_0_1 | RXH_L4_B_2_3):
+			/* If VLAN hashing is also requested for ESP then do not
+			 * allow because of hardware 40 bytes flow key limit.
+			 */
+			if (rss_cfg & NIX_FLOW_KEY_TYPE_VLAN) {
+				netdev_err(pfvf->netdev,
+					   "RSS hash of ESP or AH with VLAN is not supported\n");
+				return -EOPNOTSUPP;
+			}
+
+			rss_cfg |= NIX_FLOW_KEY_TYPE_ESP | NIX_FLOW_KEY_TYPE_AH;
+			/* Disable IPv4 proto hashing since IPv6 SA+DA(32 bytes)
+			 * and ESP SPI+sequence(8 bytes) uses hardware maximum
+			 * limit of 40 byte flow key.
+			 */
+			rss_cfg &= ~NIX_FLOW_KEY_TYPE_IPV4_PROTO;
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
 	case IPV4_FLOW:
 	case IPV6_FLOW:
 		rss_cfg = NIX_FLOW_KEY_TYPE_IPV4 | NIX_FLOW_KEY_TYPE_IPV6;