From eb79e640fab1fc163e6f04e0cc007c76b6a46f28 Mon Sep 17 00:00:00 2001 From: "Lendacky, Thomas" Date: Thu, 20 Nov 2014 11:04:02 -0600 Subject: [PATCH] amd-xgbe: Perform Tx coalescing on a packet basis The current form of Tx coalescing works on a descriptor basis instead of on a packet basis and doesn't take into account TSO packets. Update the Tx coalescing support to work on a packet basis, taking into account the number of packets associated with a TSO transmit. Also, only activate the Tx timer if a timer value is set. Signed-off-by: Tom Lendacky Signed-off-by: David S. Miller --- drivers/net/ethernet/amd/xgbe/xgbe-dev.c | 46 +++++++++++++----------- 1 file changed, 26 insertions(+), 20 deletions(-) diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c index 78db5a657699..b3d2433b52bb 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c @@ -1334,7 +1334,7 @@ static void xgbe_dev_xmit(struct xgbe_channel *channel) struct xgbe_packet_data *packet = &ring->packet_data; unsigned int csum, tso, vlan; unsigned int tso_context, vlan_context; - unsigned int tx_coalesce, tx_frames; + unsigned int tx_set_ic; int start_index = ring->cur; int i; @@ -1357,10 +1357,26 @@ static void xgbe_dev_xmit(struct xgbe_channel *channel) else vlan_context = 0; - tx_coalesce = (pdata->tx_usecs || pdata->tx_frames) ? 1 : 0; - tx_frames = pdata->tx_frames; - if (tx_coalesce && !channel->tx_timer_active) - ring->coalesce_count = 0; + /* Determine if an interrupt should be generated for this Tx: + * Interrupt: + * - Tx frame count exceeds the frame count setting + * - Addition of Tx frame count to the frame count since the + * last interrupt was set exceeds the frame count setting + * No interrupt: + * - No frame count setting specified (ethtool -C ethX tx-frames 0) + * - Addition of Tx frame count to the frame count since the + * last interrupt was set does not exceed the frame count setting + */ + ring->coalesce_count += packet->tx_packets; + if (!pdata->tx_frames) + tx_set_ic = 0; + else if (packet->tx_packets > pdata->tx_frames) + tx_set_ic = 1; + else if ((ring->coalesce_count % pdata->tx_frames) < + packet->tx_packets) + tx_set_ic = 1; + else + tx_set_ic = 0; rdata = XGBE_GET_DESC_DATA(ring, ring->cur); rdesc = rdata->rdesc; @@ -1427,13 +1443,6 @@ static void xgbe_dev_xmit(struct xgbe_channel *channel) if (XGMAC_GET_BITS(packet->attributes, TX_PACKET_ATTRIBUTES, PTP)) XGMAC_SET_BITS_LE(rdesc->desc2, TX_NORMAL_DESC2, TTSE, 1); - /* Set IC bit based on Tx coalescing settings */ - XGMAC_SET_BITS_LE(rdesc->desc2, TX_NORMAL_DESC2, IC, 1); - if (tx_coalesce && (!tx_frames || - (++ring->coalesce_count % tx_frames))) - /* Clear IC bit */ - XGMAC_SET_BITS_LE(rdesc->desc2, TX_NORMAL_DESC2, IC, 0); - /* Mark it as First Descriptor */ XGMAC_SET_BITS_LE(rdesc->desc3, TX_NORMAL_DESC3, FD, 1); @@ -1478,13 +1487,6 @@ static void xgbe_dev_xmit(struct xgbe_channel *channel) XGMAC_SET_BITS_LE(rdesc->desc2, TX_NORMAL_DESC2, HL_B1L, rdata->skb_dma_len); - /* Set IC bit based on Tx coalescing settings */ - XGMAC_SET_BITS_LE(rdesc->desc2, TX_NORMAL_DESC2, IC, 1); - if (tx_coalesce && (!tx_frames || - (++ring->coalesce_count % tx_frames))) - /* Clear IC bit */ - XGMAC_SET_BITS_LE(rdesc->desc2, TX_NORMAL_DESC2, IC, 0); - /* Set OWN bit */ XGMAC_SET_BITS_LE(rdesc->desc3, TX_NORMAL_DESC3, OWN, 1); @@ -1500,6 +1502,10 @@ static void xgbe_dev_xmit(struct xgbe_channel *channel) /* Set LAST bit for the last descriptor */ XGMAC_SET_BITS_LE(rdesc->desc3, TX_NORMAL_DESC3, LD, 1); + /* Set IC bit based on Tx coalescing settings */ + if (tx_set_ic) + XGMAC_SET_BITS_LE(rdesc->desc2, TX_NORMAL_DESC2, IC, 1); + /* Save the Tx info to report back during cleanup */ rdata->tx.packets = packet->tx_packets; rdata->tx.bytes = packet->tx_bytes; @@ -1530,7 +1536,7 @@ static void xgbe_dev_xmit(struct xgbe_channel *channel) lower_32_bits(rdata->rdesc_dma)); /* Start the Tx coalescing timer */ - if (tx_coalesce && !channel->tx_timer_active) { + if (pdata->tx_usecs && !channel->tx_timer_active) { channel->tx_timer_active = 1; hrtimer_start(&channel->tx_timer, ktime_set(0, pdata->tx_usecs * NSEC_PER_USEC), -- 2.20.1