From 1679c72cf48552e75a624b9c9230e2c7c18cfffc Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Fri, 11 Sep 2020 23:40:03 +0100 Subject: [PATCH] sfc: de-indirect TSO handling Remove the tx_queue->handle_tso function pointer, and just use tx_queue->tso_version to decide which function to call, thus removing an indirect call from the fast path. Instead of passing a tso_v2 flag to efx_mcdi_tx_init(), set the desired tx_queue->tso_version before calling it. In efx_mcdi_tx_init(), report back failure to obtain a TSOv2 context by setting tx_queue->tso_version to 0, which will cause the TX path to use the GSO-based fallback. Signed-off-by: Edward Cree Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/ef10.c | 35 +++++++++++++------------------ drivers/net/ethernet/sfc/ef100_tx.c | 9 +++++++- drivers/net/ethernet/sfc/farch.c | 2 ++ drivers/net/ethernet/sfc/mcdi_functions.c | 6 ++++-- drivers/net/ethernet/sfc/mcdi_functions.h | 2 +- drivers/net/ethernet/sfc/net_driver.h | 5 ----- drivers/net/ethernet/sfc/nic.h | 4 ++++ drivers/net/ethernet/sfc/tx.c | 14 +++++++++++-- drivers/net/ethernet/sfc/tx_common.c | 6 +----- 9 files changed, 46 insertions(+), 37 deletions(-) diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c index 1c1bc0d..c6507d1 100644 --- a/drivers/net/ethernet/sfc/ef10.c +++ b/drivers/net/ethernet/sfc/ef10.c @@ -2175,9 +2175,8 @@ static inline void efx_ef10_push_tx_desc(struct efx_tx_queue *tx_queue, /* Add Firmware-Assisted TSO v2 option descriptors to a queue. */ -static int efx_ef10_tx_tso_desc(struct efx_tx_queue *tx_queue, - struct sk_buff *skb, - bool *data_mapped) +int efx_ef10_tx_tso_desc(struct efx_tx_queue *tx_queue, struct sk_buff *skb, + bool *data_mapped) { struct efx_tx_buffer *buffer; struct tcphdr *tcp; @@ -2266,7 +2265,6 @@ static void efx_ef10_tx_init(struct efx_tx_queue *tx_queue) struct efx_channel *channel = tx_queue->channel; struct efx_nic *efx = tx_queue->efx; struct efx_ef10_nic_data *nic_data; - bool tso_v2 = false; efx_qword_t *txd; int rc; @@ -2289,15 +2287,18 @@ static void efx_ef10_tx_init(struct efx_tx_queue *tx_queue) * TSOv2 cannot be used with Hardware timestamping, and is never needed * for XDP tx. */ - if ((csum_offload || inner_csum) && (nic_data->datapath_caps2 & - (1 << MC_CMD_GET_CAPABILITIES_V2_OUT_TX_TSO_V2_LBN)) && - !tx_queue->timestamping && !tx_queue->xdp_tx) { - tso_v2 = true; - netif_dbg(efx, hw, efx->net_dev, "Using TSOv2 for channel %u\n", - channel->channel); + if (efx_has_cap(efx, TX_TSO_V2)) { + if ((csum_offload || inner_csum) && + !tx_queue->timestamping && !tx_queue->xdp_tx) { + tx_queue->tso_version = 2; + netif_dbg(efx, hw, efx->net_dev, "Using TSOv2 for channel %u\n", + channel->channel); + } + } else if (efx_has_cap(efx, TX_TSO)) { + tx_queue->tso_version = 1; } - rc = efx_mcdi_tx_init(tx_queue, tso_v2); + rc = efx_mcdi_tx_init(tx_queue); if (rc) goto fail; @@ -2315,20 +2316,12 @@ static void efx_ef10_tx_init(struct efx_tx_queue *tx_queue) ESF_DZ_TX_OPTION_TYPE, ESE_DZ_TX_OPTION_DESC_CRC_CSUM, ESF_DZ_TX_OPTION_UDP_TCP_CSUM, csum_offload, - ESF_DZ_TX_OPTION_IP_CSUM, csum_offload && !tso_v2, + ESF_DZ_TX_OPTION_IP_CSUM, csum_offload && tx_queue->tso_version != 2, ESF_DZ_TX_OPTION_INNER_UDP_TCP_CSUM, inner_csum, - ESF_DZ_TX_OPTION_INNER_IP_CSUM, inner_csum && !tso_v2, + ESF_DZ_TX_OPTION_INNER_IP_CSUM, inner_csum && tx_queue->tso_version != 2, ESF_DZ_TX_TIMESTAMP, tx_queue->timestamping); tx_queue->write_count = 1; - if (tso_v2) { - tx_queue->handle_tso = efx_ef10_tx_tso_desc; - tx_queue->tso_version = 2; - } else if (nic_data->datapath_caps & - (1 << MC_CMD_GET_CAPABILITIES_OUT_TX_TSO_LBN)) { - tx_queue->tso_version = 1; - } - wmb(); efx_ef10_push_tx_desc(tx_queue, txd); diff --git a/drivers/net/ethernet/sfc/ef100_tx.c b/drivers/net/ethernet/sfc/ef100_tx.c index ef9c2e8..a90e5a9 100644 --- a/drivers/net/ethernet/sfc/ef100_tx.c +++ b/drivers/net/ethernet/sfc/ef100_tx.c @@ -37,7 +37,14 @@ void ef100_tx_init(struct efx_tx_queue *tx_queue) tx_queue->channel->channel - tx_queue->efx->tx_channel_offset); - if (efx_mcdi_tx_init(tx_queue, false)) + /* This value is purely documentational; as EF100 never passes through + * the switch statement in tx.c:__efx_enqueue_skb(), that switch does + * not handle case 3. EF100's TSOv3 descriptors are generated by + * ef100_make_tso_desc(). + * Meanwhile, all efx_mcdi_tx_init() cares about is that it's not 2. + */ + tx_queue->tso_version = 3; + if (efx_mcdi_tx_init(tx_queue)) netdev_WARN(tx_queue->efx->net_dev, "failed to initialise TXQ %d\n", tx_queue->queue); } diff --git a/drivers/net/ethernet/sfc/farch.c b/drivers/net/ethernet/sfc/farch.c index bb5c45a..d75cf5f 100644 --- a/drivers/net/ethernet/sfc/farch.c +++ b/drivers/net/ethernet/sfc/farch.c @@ -415,6 +415,8 @@ void efx_farch_tx_init(struct efx_tx_queue *tx_queue) FFE_BZ_TX_PACE_OFF : FFE_BZ_TX_PACE_RESERVED); efx_writeo_table(efx, ®, FR_BZ_TX_PACE_TBL, tx_queue->queue); + + tx_queue->tso_version = 1; } static void efx_farch_flush_tx_queue(struct efx_tx_queue *tx_queue) diff --git a/drivers/net/ethernet/sfc/mcdi_functions.c b/drivers/net/ethernet/sfc/mcdi_functions.c index 58582a0..d3e6d82 100644 --- a/drivers/net/ethernet/sfc/mcdi_functions.c +++ b/drivers/net/ethernet/sfc/mcdi_functions.c @@ -160,7 +160,7 @@ fail: outbuf, outlen, rc); } -int efx_mcdi_tx_init(struct efx_tx_queue *tx_queue, bool tso_v2) +int efx_mcdi_tx_init(struct efx_tx_queue *tx_queue) { MCDI_DECLARE_BUF(inbuf, MC_CMD_INIT_TXQ_IN_LEN(EFX_MAX_DMAQ_SIZE * 8 / EFX_BUF_SIZE)); @@ -195,6 +195,8 @@ int efx_mcdi_tx_init(struct efx_tx_queue *tx_queue, bool tso_v2) inlen = MC_CMD_INIT_TXQ_IN_LEN(entries); do { + bool tso_v2 = tx_queue->tso_version == 2; + /* TSOv2 implies IP header checksum offload for TSO frames, * so we can safely disable IP header checksum offload for * everything else. If we don't have TSOv2, then we have to @@ -217,7 +219,7 @@ int efx_mcdi_tx_init(struct efx_tx_queue *tx_queue, bool tso_v2) NULL, 0, NULL); if (rc == -ENOSPC && tso_v2) { /* Retry without TSOv2 if we're short on contexts. */ - tso_v2 = false; + tx_queue->tso_version = 0; netif_warn(efx, probe, efx->net_dev, "TSOv2 context not available to segment in " "hardware. TCP performance may be reduced.\n" diff --git a/drivers/net/ethernet/sfc/mcdi_functions.h b/drivers/net/ethernet/sfc/mcdi_functions.h index 687be8b..b0e2f53 100644 --- a/drivers/net/ethernet/sfc/mcdi_functions.h +++ b/drivers/net/ethernet/sfc/mcdi_functions.h @@ -19,7 +19,7 @@ int efx_mcdi_ev_probe(struct efx_channel *channel); int efx_mcdi_ev_init(struct efx_channel *channel, bool v1_cut_thru, bool v2); void efx_mcdi_ev_remove(struct efx_channel *channel); void efx_mcdi_ev_fini(struct efx_channel *channel); -int efx_mcdi_tx_init(struct efx_tx_queue *tx_queue, bool tso_v2); +int efx_mcdi_tx_init(struct efx_tx_queue *tx_queue); void efx_mcdi_tx_remove(struct efx_tx_queue *tx_queue); void efx_mcdi_tx_fini(struct efx_tx_queue *tx_queue); int efx_mcdi_rx_probe(struct efx_rx_queue *rx_queue); diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h index ed444e1..ddcd1c4 100644 --- a/drivers/net/ethernet/sfc/net_driver.h +++ b/drivers/net/ethernet/sfc/net_driver.h @@ -208,8 +208,6 @@ struct efx_tx_buffer { * @initialised: Has hardware queue been initialised? * @timestamping: Is timestamping enabled for this channel? * @xdp_tx: Is this an XDP tx queue? - * @handle_tso: TSO xmit preparation handler. Sets up the TSO metadata and - * may also map tx data, depending on the nature of the TSO implementation. * @read_count: Current read pointer. * This is the number of buffers that have been removed from both rings. * @old_write_count: The value of @write_count when last checked. @@ -272,9 +270,6 @@ struct efx_tx_queue { bool timestamping; bool xdp_tx; - /* Function pointers used in the fast path. */ - int (*handle_tso)(struct efx_tx_queue*, struct sk_buff*, bool *); - /* Members used mainly on the completion path */ unsigned int read_count ____cacheline_aligned_in_smp; unsigned int old_write_count; diff --git a/drivers/net/ethernet/sfc/nic.h b/drivers/net/ethernet/sfc/nic.h index 724e277..5c2fe3c 100644 --- a/drivers/net/ethernet/sfc/nic.h +++ b/drivers/net/ethernet/sfc/nic.h @@ -297,6 +297,10 @@ struct efx_ef10_nic_data { u64 licensed_features; }; +/* TSOv2 */ +int efx_ef10_tx_tso_desc(struct efx_tx_queue *tx_queue, struct sk_buff *skb, + bool *data_mapped); + int efx_init_sriov(void); void efx_fini_sriov(void); diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c index 13e960b..1665529 100644 --- a/drivers/net/ethernet/sfc/tx.c +++ b/drivers/net/ethernet/sfc/tx.c @@ -338,8 +338,18 @@ netdev_tx_t __efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb * size limit. */ if (segments) { - EFX_WARN_ON_ONCE_PARANOID(!tx_queue->handle_tso); - rc = tx_queue->handle_tso(tx_queue, skb, &data_mapped); + switch (tx_queue->tso_version) { + case 1: + rc = efx_enqueue_skb_tso(tx_queue, skb, &data_mapped); + break; + case 2: + rc = efx_ef10_tx_tso_desc(tx_queue, skb, &data_mapped); + break; + case 0: /* No TSO on this queue, SW fallback needed */ + default: + rc = -EINVAL; + break; + } if (rc == -EINVAL) { rc = efx_tx_tso_fallback(tx_queue, skb); tx_queue->tso_fallbacks++; diff --git a/drivers/net/ethernet/sfc/tx_common.c b/drivers/net/ethernet/sfc/tx_common.c index 2feff2e..d530cde 100644 --- a/drivers/net/ethernet/sfc/tx_common.c +++ b/drivers/net/ethernet/sfc/tx_common.c @@ -86,11 +86,7 @@ void efx_init_tx_queue(struct efx_tx_queue *tx_queue) tx_queue->completed_timestamp_minor = 0; tx_queue->xdp_tx = efx_channel_is_xdp_tx(tx_queue->channel); - - /* Set up default function pointers. These may get replaced by - * efx_nic_init_tx() based off NIC/queue capabilities. - */ - tx_queue->handle_tso = efx_enqueue_skb_tso; + tx_queue->tso_version = 0; /* Set up TX descriptor ring */ efx_nic_init_tx(tx_queue); -- 2.7.4