i40e: skb->xmit_more support
Support skb->xmit_more in i40e is straightforward : we need to move
around i40e_maybe_stop_tx() call to correctly test netif_xmit_stopped()
before taking the decision to not kick the NIC.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 267992b..3195d82 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2053,6 +2053,47 @@
}
/**
+ * __i40e_maybe_stop_tx - 2nd level check for tx stop conditions
+ * @tx_ring: the ring to be checked
+ * @size: the size buffer we want to assure is available
+ *
+ * Returns -EBUSY if a stop is needed, else 0
+ **/
+static inline int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
+{
+ netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
+ /* Memory barrier before checking head and tail */
+ smp_mb();
+
+ /* Check again in a case another CPU has just made room available. */
+ if (likely(I40E_DESC_UNUSED(tx_ring) < size))
+ return -EBUSY;
+
+ /* A reprieve! - use start_queue because it doesn't call schedule */
+ netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
+ ++tx_ring->tx_stats.restart_queue;
+ return 0;
+}
+
+/**
+ * i40e_maybe_stop_tx - 1st level check for tx stop conditions
+ * @tx_ring: the ring to be checked
+ * @size: the size buffer we want to assure is available
+ *
+ * Returns 0 if stop is not needed
+ **/
+#ifdef I40E_FCOE
+int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
+#else
+static int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
+#endif
+{
+ if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
+ return 0;
+ return __i40e_maybe_stop_tx(tx_ring, size);
+}
+
+/**
* i40e_tx_map - Build the Tx descriptor
* @tx_ring: ring to send buffer on
* @skb: send buffer
@@ -2195,8 +2236,12 @@
tx_ring->next_to_use = i;
+ i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
/* notify HW of packet */
- writel(i, tx_ring->tail);
+ if (!skb->xmit_more ||
+ netif_xmit_stopped(netdev_get_tx_queue(tx_ring->netdev,
+ tx_ring->queue_index)))
+ writel(i, tx_ring->tail);
return;
@@ -2218,47 +2263,6 @@
}
/**
- * __i40e_maybe_stop_tx - 2nd level check for tx stop conditions
- * @tx_ring: the ring to be checked
- * @size: the size buffer we want to assure is available
- *
- * Returns -EBUSY if a stop is needed, else 0
- **/
-static inline int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
-{
- netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
- /* Memory barrier before checking head and tail */
- smp_mb();
-
- /* Check again in a case another CPU has just made room available. */
- if (likely(I40E_DESC_UNUSED(tx_ring) < size))
- return -EBUSY;
-
- /* A reprieve! - use start_queue because it doesn't call schedule */
- netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
- ++tx_ring->tx_stats.restart_queue;
- return 0;
-}
-
-/**
- * i40e_maybe_stop_tx - 1st level check for tx stop conditions
- * @tx_ring: the ring to be checked
- * @size: the size buffer we want to assure is available
- *
- * Returns 0 if stop is not needed
- **/
-#ifdef I40E_FCOE
-int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
-#else
-static int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
-#endif
-{
- if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
- return 0;
- return __i40e_maybe_stop_tx(tx_ring, size);
-}
-
-/**
* i40e_xmit_descriptor_count - calculate number of tx descriptors needed
* @skb: send buffer
* @tx_ring: ring to send buffer on
@@ -2372,8 +2376,6 @@
i40e_tx_map(tx_ring, skb, first, tx_flags, hdr_len,
td_cmd, td_offset);
- i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
-
return NETDEV_TX_OK;
out_drop: