sfc: remove Software TSO
It gives no advantage over GSO now that xmit_more exists. If we find
ourselves unable to handle a TSO skb (because our TXQ doesn't have a
TSOv2 context and the NIC doesn't support TSOv1), hand it back to GSO.
Also do that if the TSO handler fails with EINVAL for any other reason.
As Falcon-architecture NICs don't support any firmware-assisted TSO,
they no longer advertise TSO feature flags at all.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 3089e88..1aa728c 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -446,10 +446,38 @@ static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)
}
}
-static int efx_tx_tso_sw(struct efx_tx_queue *tx_queue, struct sk_buff *skb,
- bool *data_mapped)
+/*
+ * Fallback to software TSO.
+ *
+ * This is used if we are unable to send a GSO packet through hardware TSO.
+ * This should only ever happen due to per-queue restrictions - unsupported
+ * packets should first be filtered by the feature flags.
+ *
+ * Returns 0 on success, error code otherwise.
+ */
+static int efx_tx_tso_fallback(struct efx_tx_queue *tx_queue,
+ struct sk_buff *skb)
{
- return efx_enqueue_skb_tso(tx_queue, skb, data_mapped);
+ struct sk_buff *segments, *next;
+
+ segments = skb_gso_segment(skb, 0);
+ if (IS_ERR(segments))
+ return PTR_ERR(segments);
+
+ dev_kfree_skb_any(skb);
+ skb = segments;
+
+ while (skb) {
+ next = skb->next;
+ skb->next = NULL;
+
+ if (next)
+ skb->xmit_more = true;
+ efx_enqueue_skb(tx_queue, skb);
+ skb = next;
+ }
+
+ return 0;
}
/*
@@ -473,6 +501,7 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
bool data_mapped = false;
unsigned int segments;
unsigned int skb_len;
+ int rc;
skb_len = skb->len;
segments = skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 0;
@@ -485,7 +514,14 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
*/
if (segments) {
EFX_BUG_ON_PARANOID(!tx_queue->handle_tso);
- if (tx_queue->handle_tso(tx_queue, skb, &data_mapped))
+ rc = tx_queue->handle_tso(tx_queue, skb, &data_mapped);
+ if (rc == -EINVAL) {
+ rc = efx_tx_tso_fallback(tx_queue, skb);
+ tx_queue->tso_fallbacks++;
+ if (rc == 0)
+ return 0;
+ }
+ if (rc)
goto err;
#ifdef EFX_USE_PIO
} else if (skb_len <= efx_piobuf_size && !skb->xmit_more &&
@@ -801,7 +837,7 @@ void efx_init_tx_queue(struct efx_tx_queue *tx_queue)
/* Set up default function pointers. These may get replaced by
* efx_nic_init_tx() based off NIC/queue capabilities.
*/
- tx_queue->handle_tso = efx_tx_tso_sw;
+ tx_queue->handle_tso = efx_enqueue_skb_tso;
/* Some older hardware requires Tx writes larger than 32. */
tx_queue->tx_min_size = EFX_WORKAROUND_15592(efx) ? 33 : 0;