From a33a4c73810589f80b8a37477e1b28b4c1d61913 Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Thu, 3 Nov 2016 22:12:27 +0000 Subject: [PATCH] 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: Edward Cree Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/ef10.c | 82 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c index 00279da6a1e8..9f6d7690bc0a 100644 --- a/drivers/net/ethernet/sfc/ef10.c +++ b/drivers/net/ethernet/sfc/ef10.c @@ -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; } -- 2.11.0