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 <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
index 78db5a6..b3d2433 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
@@ -1334,7 +1334,7 @@
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 @@
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 @@
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 @@
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 @@
/* 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 @@
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),