Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a33a4c73 authored by Edward Cree's avatar Edward Cree Committed by David S. Miller
Browse files

sfc: enable 4-tuple RSS hashing for UDP 



This improves UDP spreading, and also slightly improves GRO performance
of encapsulated TCP on 7000 series NICs.

Signed-off-by: default avatarEdward Cree <ecree@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 04b206b8

drivers/net/ethernet/sfc/ef10.c

+82 −0
Original line number Diff line number Diff line
@@ -2245,6 +2245,84 @@ static void efx_ef10_tx_write(struct efx_tx_queue *tx_queue) 
	}

}



#define RSS_MODE_HASH_ADDRS	(1 << RSS_MODE_HASH_SRC_ADDR_LBN |\

				 1 << RSS_MODE_HASH_DST_ADDR_LBN)

#define RSS_MODE_HASH_PORTS	(1 << RSS_MODE_HASH_SRC_PORT_LBN |\

				 1 << RSS_MODE_HASH_DST_PORT_LBN)

#define RSS_CONTEXT_FLAGS_DEFAULT	(1 << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_TOEPLITZ_IPV4_EN_LBN |\

					 1 << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_TOEPLITZ_TCPV4_EN_LBN |\

					 1 << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_TOEPLITZ_IPV6_EN_LBN |\

					 1 << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_TOEPLITZ_TCPV6_EN_LBN |\

					 (RSS_MODE_HASH_ADDRS | RSS_MODE_HASH_PORTS) << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_TCP_IPV4_RSS_MODE_LBN |\

					 RSS_MODE_HASH_ADDRS << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_UDP_IPV4_RSS_MODE_LBN |\

					 RSS_MODE_HASH_ADDRS << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_OTHER_IPV4_RSS_MODE_LBN |\

					 (RSS_MODE_HASH_ADDRS | RSS_MODE_HASH_PORTS) << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_TCP_IPV6_RSS_MODE_LBN |\

					 RSS_MODE_HASH_ADDRS << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_UDP_IPV6_RSS_MODE_LBN |\

					 RSS_MODE_HASH_ADDRS << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_OTHER_IPV6_RSS_MODE_LBN)



static int efx_ef10_get_rss_flags(struct efx_nic *efx, u32 context, u32 *flags)

{

	/* Firmware had a bug (sfc bug 61952) where it would not actually

	 * fill in the flags field in the response to MC_CMD_RSS_CONTEXT_GET_FLAGS.

	 * This meant that it would always contain whatever was previously

	 * in the MCDI buffer.  Fortunately, all firmware versions with

	 * this bug have the same default flags value for a newly-allocated

	 * RSS context, and the only time we want to get the flags is just

	 * after allocating.  Moreover, the response has a 32-bit hole

	 * where the context ID would be in the request, so we can use an

	 * overlength buffer in the request and pre-fill the flags field

	 * with what we believe the default to be.  Thus if the firmware

	 * has the bug, it will leave our pre-filled value in the flags

	 * field of the response, and we will get the right answer.

	 *

	 * However, this does mean that this function should NOT be used if

	 * the RSS context flags might not be their defaults - it is ONLY

	 * reliably correct for a newly-allocated RSS context.

	 */

	MCDI_DECLARE_BUF(inbuf, MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_LEN);

	MCDI_DECLARE_BUF(outbuf, MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_LEN);

	size_t outlen;

	int rc;



	/* Check we have a hole for the context ID */

	BUILD_BUG_ON(MC_CMD_RSS_CONTEXT_GET_FLAGS_IN_LEN != MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_FLAGS_OFST);

	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_GET_FLAGS_IN_RSS_CONTEXT_ID, context);

	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_GET_FLAGS_OUT_FLAGS,

		       RSS_CONTEXT_FLAGS_DEFAULT);

	rc = efx_mcdi_rpc(efx, MC_CMD_RSS_CONTEXT_GET_FLAGS, inbuf,

			  sizeof(inbuf), outbuf, sizeof(outbuf), &outlen);

	if (rc == 0) {

		if (outlen < MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_LEN)

			rc = -EIO;

		else

			*flags = MCDI_DWORD(outbuf, RSS_CONTEXT_GET_FLAGS_OUT_FLAGS);

	}

	return rc;

}



/* Attempt to enable 4-tuple UDP hashing on the specified RSS context.

 * If we fail, we just leave the RSS context at its default hash settings,

 * which is safe but may slightly reduce performance.

 * Defaults are 4-tuple for TCP and 2-tuple for UDP and other-IP, so we

 * just need to set the UDP ports flags (for both IP versions).

 */

static void efx_ef10_set_rss_flags(struct efx_nic *efx, u32 context)

{

	MCDI_DECLARE_BUF(inbuf, MC_CMD_RSS_CONTEXT_SET_FLAGS_IN_LEN);

	u32 flags;



	BUILD_BUG_ON(MC_CMD_RSS_CONTEXT_SET_FLAGS_OUT_LEN != 0);



	if (efx_ef10_get_rss_flags(efx, context, &flags) != 0)

		return;

	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_SET_FLAGS_IN_RSS_CONTEXT_ID, context);

	flags |= RSS_MODE_HASH_PORTS << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_UDP_IPV4_RSS_MODE_LBN;

	flags |= RSS_MODE_HASH_PORTS << MC_CMD_RSS_CONTEXT_GET_FLAGS_OUT_UDP_IPV6_RSS_MODE_LBN;

	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_SET_FLAGS_IN_FLAGS, flags);

	efx_mcdi_rpc(efx, MC_CMD_RSS_CONTEXT_SET_FLAGS, inbuf, sizeof(inbuf),

		     NULL, 0, NULL);

}



static int efx_ef10_alloc_rss_context(struct efx_nic *efx, u32 *context,

				      bool exclusive, unsigned *context_size)

{
@@ -2290,6 +2368,10 @@ static int efx_ef10_alloc_rss_context(struct efx_nic *efx, u32 *context, 
	if (context_size)

		*context_size = rss_spread;



	if (nic_data->datapath_caps &

	    1 << MC_CMD_GET_CAPABILITIES_OUT_ADDITIONAL_RSS_MODES_LBN)

		efx_ef10_set_rss_flags(efx, *context);



	return 0;

}