net: intel: introduce {, Intel} Ethernet common library

Not a secret there's a ton of code duplication between two and more Intel
ethernet modules.

Before introducing new changes, which would need to be copied over again,
start decoupling the already existing duplicate functionality into a new
module, which will be shared between several Intel Ethernet drivers.
Add the lookup table which converts 8/10-bit hardware packet type into
a parsed bitfield structure for easy checking packet format parameters,
such as payload level, IP version, etc. This is currently used by i40e,
ice and iavf and it's all the same in all three drivers.
The only difference introduced in this implementation is that instead of
defining a 256 (or 1024 in case of ice) element array, add unlikely()
condition to limit the input to 154 (current maximum non-reserved packet
type). There's no reason to waste 600 (or even 3600) bytes only to not
hurt very unlikely exception packets.
The hash computation function now takes payload level directly as a
pkt_hash_type. There's a couple cases when non-IP ptypes are marked as
L3 payload and in the previous versions their hash level would be 2, not
3. But skb_set_hash() only sees difference between L4 and non-L4, thus
this won't change anything at all.
The module is behind the hidden Kconfig symbol, which the drivers will
select when needed. The exports are behind 'LIBIE' namespace to limit
the scope of the functions.

Not that non-HW-specific symbols will live in yet another module,
libeth. This is done to easily distinguish pretty generic code ready
for reusing by any other vendor and/or for moving the layer up from
the code useful in Intel's 1-100G drivers only.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 124 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/libie/rx.c b/drivers/net/ethernet/intel/libie/rx.c
new file mode 100644
index 000000000000..38201ee1e891
--- /dev/null
+++ b/drivers/net/ethernet/intel/libie/rx.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2024 Intel Corporation */
+
+#include <linux/net/intel/libie/rx.h>
+
+/* O(1) converting i40e/ice/iavf's 8/10-bit hardware packet type to a parsed
+ * bitfield struct.
+ */
+
+/* A few supplementary definitions for when XDP hash types do not coincide
+ * with what can be generated from ptype definitions by means of preprocessor
+ * concatenation.
+ */
+#define XDP_RSS_L3_L2			XDP_RSS_TYPE_NONE
+#define XDP_RSS_L4_NONE			XDP_RSS_TYPE_NONE
+#define XDP_RSS_L4_TIMESYNC		XDP_RSS_TYPE_NONE
+#define XDP_RSS_TYPE_L3			XDP_RSS_TYPE_NONE
+#define XDP_RSS_TYPE_L4			XDP_RSS_L4
+
+#define LIBIE_RX_PT(oip, ofrag, tun, tp, tefr, iprot, pl) {		   \
+		.outer_ip		= LIBETH_RX_PT_OUTER_##oip,	   \
+		.outer_frag		= LIBETH_RX_PT_##ofrag,		   \
+		.tunnel_type		= LIBETH_RX_PT_TUNNEL_IP_##tun,	   \
+		.tunnel_end_prot	= LIBETH_RX_PT_TUNNEL_END_##tp,	   \
+		.tunnel_end_frag	= LIBETH_RX_PT_##tefr,		   \
+		.inner_prot		= LIBETH_RX_PT_INNER_##iprot,	   \
+		.payload_layer		= LIBETH_RX_PT_PAYLOAD_##pl,	   \
+		.hash_type		= XDP_RSS_L3_##oip |		   \
+					  XDP_RSS_L4_##iprot |		   \
+					  XDP_RSS_TYPE_##pl,		   \
+	}
+
+#define LIBIE_RX_PT_UNUSED		{ }
+
+#define __LIBIE_RX_PT_L2(iprot, pl)					   \
+	LIBIE_RX_PT(L2, NOT_FRAG, NONE, NONE, NOT_FRAG, iprot, pl)
+#define LIBIE_RX_PT_L2		__LIBIE_RX_PT_L2(NONE, L2)
+#define LIBIE_RX_PT_TS		__LIBIE_RX_PT_L2(TIMESYNC, L2)
+#define LIBIE_RX_PT_L3		__LIBIE_RX_PT_L2(NONE, L3)
+
+#define LIBIE_RX_PT_IP_FRAG(oip)					   \
+	LIBIE_RX_PT(IPV##oip, FRAG, NONE, NONE, NOT_FRAG, NONE, L3)
+#define LIBIE_RX_PT_IP_L3(oip, tun, teprot, tefr)			   \
+	LIBIE_RX_PT(IPV##oip, NOT_FRAG, tun, teprot, tefr, NONE, L3)
+#define LIBIE_RX_PT_IP_L4(oip, tun, teprot, iprot)			   \
+	LIBIE_RX_PT(IPV##oip, NOT_FRAG, tun, teprot, NOT_FRAG, iprot, L4)
+
+#define LIBIE_RX_PT_IP_NOF(oip, tun, ver)				   \
+	LIBIE_RX_PT_IP_L3(oip, tun, ver, NOT_FRAG),			   \
+	LIBIE_RX_PT_IP_L4(oip, tun, ver, UDP),				   \
+	LIBIE_RX_PT_UNUSED,						   \
+	LIBIE_RX_PT_IP_L4(oip, tun, ver, TCP),				   \
+	LIBIE_RX_PT_IP_L4(oip, tun, ver, SCTP),				   \
+	LIBIE_RX_PT_IP_L4(oip, tun, ver, ICMP)
+
+/* IPv oip --> tun --> IPv ver */
+#define LIBIE_RX_PT_IP_TUN_VER(oip, tun, ver)				   \
+	LIBIE_RX_PT_IP_L3(oip, tun, ver, FRAG),				   \
+	LIBIE_RX_PT_IP_NOF(oip, tun, ver)
+
+/* Non Tunneled IPv oip */
+#define LIBIE_RX_PT_IP_RAW(oip)						   \
+	LIBIE_RX_PT_IP_FRAG(oip),					   \
+	LIBIE_RX_PT_IP_NOF(oip, NONE, NONE)
+
+/* IPv oip --> tun --> { IPv4, IPv6 } */
+#define LIBIE_RX_PT_IP_TUN(oip, tun)					   \
+	LIBIE_RX_PT_IP_TUN_VER(oip, tun, IPV4),				   \
+	LIBIE_RX_PT_IP_TUN_VER(oip, tun, IPV6)
+
+/* IPv oip --> GRE/NAT tun --> { x, IPv4, IPv6 } */
+#define LIBIE_RX_PT_IP_GRE(oip, tun)					   \
+	LIBIE_RX_PT_IP_L3(oip, tun, NONE, NOT_FRAG),			   \
+	LIBIE_RX_PT_IP_TUN(oip, tun)
+
+/* Non Tunneled IPv oip
+ * IPv oip --> { IPv4, IPv6 }
+ * IPv oip --> GRE/NAT --> { x, IPv4, IPv6 }
+ * IPv oip --> GRE/NAT --> MAC --> { x, IPv4, IPv6 }
+ * IPv oip --> GRE/NAT --> MAC/VLAN --> { x, IPv4, IPv6 }
+ */
+#define LIBIE_RX_PT_IP(oip)						   \
+	LIBIE_RX_PT_IP_RAW(oip),					   \
+	LIBIE_RX_PT_IP_TUN(oip, IP),					   \
+	LIBIE_RX_PT_IP_GRE(oip, GRENAT),				   \
+	LIBIE_RX_PT_IP_GRE(oip, GRENAT_MAC),				   \
+	LIBIE_RX_PT_IP_GRE(oip, GRENAT_MAC_VLAN)
+
+/* Lookup table mapping for O(1) parsing */
+const struct libeth_rx_pt libie_rx_pt_lut[LIBIE_RX_PT_NUM] = {
+	/* L2 packet types */
+	LIBIE_RX_PT_UNUSED,
+	LIBIE_RX_PT_L2,
+	LIBIE_RX_PT_TS,
+	LIBIE_RX_PT_L2,
+	LIBIE_RX_PT_UNUSED,
+	LIBIE_RX_PT_UNUSED,
+	LIBIE_RX_PT_L2,
+	LIBIE_RX_PT_L2,
+	LIBIE_RX_PT_UNUSED,
+	LIBIE_RX_PT_UNUSED,
+	LIBIE_RX_PT_L2,
+	LIBIE_RX_PT_UNUSED,
+
+	LIBIE_RX_PT_L3,
+	LIBIE_RX_PT_L3,
+	LIBIE_RX_PT_L3,
+	LIBIE_RX_PT_L3,
+	LIBIE_RX_PT_L3,
+	LIBIE_RX_PT_L3,
+	LIBIE_RX_PT_L3,
+	LIBIE_RX_PT_L3,
+	LIBIE_RX_PT_L3,
+	LIBIE_RX_PT_L3,
+
+	LIBIE_RX_PT_IP(4),
+	LIBIE_RX_PT_IP(6),
+};
+EXPORT_SYMBOL_NS_GPL(libie_rx_pt_lut, LIBIE);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Intel(R) Ethernet common library");
+MODULE_IMPORT_NS(LIBETH);
+MODULE_LICENSE("GPL");