Re: [RFC PATCH 1/2] net: Add support for hardware-offloaded encapsulation

On Thu, 2012-10-25 at 14:16 -0700, Stephen Hemminger wrote:

On Thu, 25 Oct 2012 11:29:12 -0700
Joseph Gasparakis [off-list ref] wrote:

quoted

@@ -19,6 +19,7 @@ enum {
 	NETIF_F_IP_CSUM_BIT,		/* Can checksum TCP/UDP over IPv4. */
 	__UNUSED_NETIF_F_1,
 	NETIF_F_HW_CSUM_BIT,		/* Can checksum all the packets. */
+	NETIF_F_HW_CSUM_ENC_BIT,	/* Can checksum all inner headers */
 	NETIF_F_IPV6_CSUM_BIT,		/* Can checksum TCP/UDP over IPV6 */
 	NETIF_F_HIGHDMA_BIT,		/* Can DMA to high memory. */
 	NETIF_F_FRAGLIST_BIT,		/* Scatter/gather IO. */

@@ -52,6 +53,8 @@ enum {
 	NETIF_F_NTUPLE_BIT,		/* N-tuple filters supported */
 	NETIF_F_RXHASH_BIT,		/* Receive hashing offload */
 	NETIF_F_RXCSUM_BIT,		/* Receive checksumming offload */
+	NETIF_F_RXCSUM_ENC_BIT,		/* Receive checksuming offload */
+					/* for encapsulation */
 	NETIF_F_NOCACHE_COPY_BIT,	/* Use no-cache copyfromuser */
 	NETIF_F_LOOPBACK_BIT,		/* Enable loopback */
 	NETIF_F_RXFCS_BIT,		/* Append FCS to skb pkt data */

Add new features at the end, or reuse __UNUSED_ bits to avoid any
issues with binary compatibility. I don't think these bits are in any
userspace API, maybe ethtool?

There should be no binary compatibility issue here as feature bits are
meant to be looked up by name at run-time.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.