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, 17 insertions, 55 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 64d198ed166b..bc9e766d88cb 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2,6 +2,7 @@
 /* Copyright(c) 2013 - 2018 Intel Corporation. */
 
 #include <linux/bpf_trace.h>
+#include <linux/net/intel/libie/rx.h>
 #include <linux/prefetch.h>
 #include <linux/sctp.h>
 #include <net/mpls.h>
@@ -1741,38 +1742,30 @@ static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
 				    struct sk_buff *skb,
 				    union i40e_rx_desc *rx_desc)
 {
-	struct i40e_rx_ptype_decoded decoded;
+	struct libeth_rx_pt decoded;
 	u32 rx_error, rx_status;
 	bool ipv4, ipv6;
 	u8 ptype;
 	u64 qword;
 
-	qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
-	ptype = FIELD_GET(I40E_RXD_QW1_PTYPE_MASK, qword);
-	rx_error = FIELD_GET(I40E_RXD_QW1_ERROR_MASK, qword);
-	rx_status = FIELD_GET(I40E_RXD_QW1_STATUS_MASK, qword);
-	decoded = decode_rx_desc_ptype(ptype);
-
 	skb->ip_summed = CHECKSUM_NONE;
 
-	skb_checksum_none_assert(skb);
+	qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
+	ptype = FIELD_GET(I40E_RXD_QW1_PTYPE_MASK, qword);
 
-	/* Rx csum enabled and ip headers found? */
-	if (!(vsi->netdev->features & NETIF_F_RXCSUM))
+	decoded = libie_rx_pt_parse(ptype);
+	if (!libeth_rx_pt_has_checksum(vsi->netdev, decoded))
 		return;
 
+	rx_error = FIELD_GET(I40E_RXD_QW1_ERROR_MASK, qword);
+	rx_status = FIELD_GET(I40E_RXD_QW1_STATUS_MASK, qword);
+
 	/* did the hardware decode the packet and checksum? */
 	if (!(rx_status & BIT(I40E_RX_DESC_STATUS_L3L4P_SHIFT)))
 		return;
 
-	/* both known and outer_ip must be set for the below code to work */
-	if (!(decoded.known && decoded.outer_ip))
-		return;
-
-	ipv4 = (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP) &&
-	       (decoded.outer_ip_ver == I40E_RX_PTYPE_OUTER_IPV4);
-	ipv6 = (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP) &&
-	       (decoded.outer_ip_ver == I40E_RX_PTYPE_OUTER_IPV6);
+	ipv4 = libeth_rx_pt_get_ip_ver(decoded) == LIBETH_RX_PT_OUTER_IPV4;
+	ipv6 = libeth_rx_pt_get_ip_ver(decoded) == LIBETH_RX_PT_OUTER_IPV6;
 
 	if (ipv4 &&
 	    (rx_error & (BIT(I40E_RX_DESC_ERROR_IPE_SHIFT) |
@@ -1800,20 +1793,10 @@ static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
 	 * we need to bump the checksum level by 1 to reflect the fact that
 	 * we are indicating we validated the inner checksum.
 	 */
-	if (decoded.tunnel_type >= I40E_RX_PTYPE_TUNNEL_IP_GRENAT)
+	if (decoded.tunnel_type >= LIBETH_RX_PT_TUNNEL_IP_GRENAT)
 		skb->csum_level = 1;
 
-	/* Only report checksum unnecessary for TCP, UDP, or SCTP */
-	switch (decoded.inner_prot) {
-	case I40E_RX_PTYPE_INNER_PROT_TCP:
-	case I40E_RX_PTYPE_INNER_PROT_UDP:
-	case I40E_RX_PTYPE_INNER_PROT_SCTP:
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-		fallthrough;
-	default:
-		break;
-	}
-
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
 	return;
 
 checksum_fail:
@@ -1821,29 +1804,6 @@ checksum_fail:
 }
 
 /**
- * i40e_ptype_to_htype - get a hash type
- * @ptype: the ptype value from the descriptor
- *
- * Returns a hash type to be used by skb_set_hash
- **/
-static inline int i40e_ptype_to_htype(u8 ptype)
-{
-	struct i40e_rx_ptype_decoded decoded = decode_rx_desc_ptype(ptype);
-
-	if (!decoded.known)
-		return PKT_HASH_TYPE_NONE;
-
-	if (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP &&
-	    decoded.payload_layer == I40E_RX_PTYPE_PAYLOAD_LAYER_PAY4)
-		return PKT_HASH_TYPE_L4;
-	else if (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP &&
-		 decoded.payload_layer == I40E_RX_PTYPE_PAYLOAD_LAYER_PAY3)
-		return PKT_HASH_TYPE_L3;
-	else
-		return PKT_HASH_TYPE_L2;
-}
-
-/**
  * i40e_rx_hash - set the hash value in the skb
  * @ring: descriptor ring
  * @rx_desc: specific descriptor
@@ -1855,17 +1815,19 @@ static inline void i40e_rx_hash(struct i40e_ring *ring,
 				struct sk_buff *skb,
 				u8 rx_ptype)
 {
+	struct libeth_rx_pt decoded;
 	u32 hash;
 	const __le64 rss_mask =
 		cpu_to_le64((u64)I40E_RX_DESC_FLTSTAT_RSS_HASH <<
 			    I40E_RX_DESC_STATUS_FLTSTAT_SHIFT);
 
-	if (!(ring->netdev->features & NETIF_F_RXHASH))
+	decoded = libie_rx_pt_parse(rx_ptype);
+	if (!libeth_rx_pt_has_hash(ring->netdev, decoded))
 		return;
 
 	if ((rx_desc->wb.qword1.status_error_len & rss_mask) == rss_mask) {
 		hash = le32_to_cpu(rx_desc->wb.qword0.hi_dword.rss);
-		skb_set_hash(skb, hash, i40e_ptype_to_htype(rx_ptype));
+		libeth_rx_pt_set_hash(skb, hash, decoded);
 	}
 }