1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /****************************************************************************
3  * Driver for Solarflare network controllers and boards
4  * Copyright 2005-2006 Fen Systems Ltd.
5  * Copyright 2006-2015 Solarflare Communications Inc.
6  */
7 
8 #ifndef EFX_TX_H
9 #define EFX_TX_H
10 
11 #include <linux/types.h>
12 
13 /* Driver internal tx-path related declarations. */
14 /* What TXQ type will satisfy the checksum offloads required for this skb? */
efx_tx_csum_type_skb(struct sk_buff * skb)15 static inline unsigned int efx_tx_csum_type_skb(struct sk_buff *skb)
16 {
17 	if (skb->ip_summed != CHECKSUM_PARTIAL)
18 		return 0; /* no checksum offload */
19 
20 	if (skb->encapsulation &&
21 	    skb_checksum_start_offset(skb) == skb_inner_transport_offset(skb)) {
22 		/* we only advertise features for IPv4 and IPv6 checksums on
23 		 * encapsulated packets, so if the checksum is for the inner
24 		 * packet, it must be one of them; no further checking required.
25 		 */
26 
27 		/* Do we also need to offload the outer header checksum? */
28 		if (skb_shinfo(skb)->gso_segs > 1 &&
29 		    !(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) &&
30 		    (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM))
31 			return EFX_TXQ_TYPE_OUTER_CSUM | EFX_TXQ_TYPE_INNER_CSUM;
32 		return EFX_TXQ_TYPE_INNER_CSUM;
33 	}
34 
35 	/* similarly, we only advertise features for IPv4 and IPv6 checksums,
36 	 * so it must be one of them. No need for further checks.
37 	 */
38 	return EFX_TXQ_TYPE_OUTER_CSUM;
39 }
40 #endif /* EFX_TX_H */
41