4 files changed, 46 insertions, 9 deletions

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 70554a1b2b02..65a8d49106a4 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -1503,6 +1503,11 @@ static int efx_probe_all(struct efx_nic *efx)
                 goto fail2;
         }
 
+        BUILD_BUG_ON(EFX_DEFAULT_DMAQ_SIZE < EFX_RXQ_MIN_ENT);
+        if (WARN_ON(EFX_DEFAULT_DMAQ_SIZE < EFX_TXQ_MIN_ENT(efx))) {
+                rc = -EINVAL;
+                goto fail3;
+        }
         efx->rxq_entries = efx->txq_entries = EFX_DEFAULT_DMAQ_SIZE;
 
         rc = efx_probe_filters(efx);
@@ -2070,6 +2075,7 @@ static int efx_register_netdev(struct efx_nic *efx)
         net_dev->irq = efx->pci_dev->irq;
         net_dev->netdev_ops = &efx_netdev_ops;
         SET_ETHTOOL_OPS(net_dev, &efx_ethtool_ops);
+        net_dev->gso_max_segs = EFX_TSO_MAX_SEGS;
 
         rtnl_lock();
 
diff --git a/drivers/net/ethernet/sfc/efx.h b/drivers/net/ethernet/sfc/efx.h
index be8f9158a714..70755c97251a 100644
--- a/drivers/net/ethernet/sfc/efx.h
+++ b/drivers/net/ethernet/sfc/efx.h
@@ -30,6 +30,7 @@ extern netdev_tx_t
 efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb);
 extern void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index);
 extern int efx_setup_tc(struct net_device *net_dev, u8 num_tc);
+extern unsigned int efx_tx_max_skb_descs(struct efx_nic *efx);
 
 /* RX */
 extern int efx_probe_rx_queue(struct efx_rx_queue *rx_queue);
@@ -52,10 +53,15 @@ extern void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue);
 #define EFX_MAX_EVQ_SIZE 16384UL
 #define EFX_MIN_EVQ_SIZE 512UL
 
-/* The smallest [rt]xq_entries that the driver supports. Callers of
- * efx_wake_queue() assume that they can subsequently send at least one
- * skb. Falcon/A1 may require up to three descriptors per skb_frag. */
-#define EFX_MIN_RING_SIZE (roundup_pow_of_two(2 * 3 * MAX_SKB_FRAGS))
+/* Maximum number of TCP segments we support for soft-TSO */
+#define EFX_TSO_MAX_SEGS        100
+
+/* The smallest [rt]xq_entries that the driver supports.  RX minimum
+ * is a bit arbitrary.  For TX, we must have space for at least 2
+ * TSO skbs.
+ */
+#define EFX_RXQ_MIN_ENT         128U
+#define EFX_TXQ_MIN_ENT(efx)    (2 * efx_tx_max_skb_descs(efx))
 
 /* Filters */
 extern int efx_probe_filters(struct efx_nic *efx);
diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index 10536f93b561..8cba2df82b18 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -680,21 +680,27 @@ static int efx_ethtool_set_ringparam(struct net_device *net_dev,
                                      struct ethtool_ringparam *ring)
 {
         struct efx_nic *efx = netdev_priv(net_dev);
+        u32 txq_entries;
 
         if (ring->rx_mini_pending || ring->rx_jumbo_pending ||
             ring->rx_pending > EFX_MAX_DMAQ_SIZE ||
             ring->tx_pending > EFX_MAX_DMAQ_SIZE)
                 return -EINVAL;
 
-        if (ring->rx_pending < EFX_MIN_RING_SIZE ||
-            ring->tx_pending < EFX_MIN_RING_SIZE) {
+        if (ring->rx_pending < EFX_RXQ_MIN_ENT) {
                 netif_err(efx, drv, efx->net_dev,
-                          "TX and RX queues cannot be smaller than %ld\n",
-                          EFX_MIN_RING_SIZE);
+                          "RX queues cannot be smaller than %u\n",
+                          EFX_RXQ_MIN_ENT);
                 return -EINVAL;
         }
 
-        return efx_realloc_channels(efx, ring->rx_pending, ring->tx_pending);
+        txq_entries = max(ring->tx_pending, EFX_TXQ_MIN_ENT(efx));
+        if (txq_entries != ring->tx_pending)
+                netif_warn(efx, drv, efx->net_dev,
+                           "increasing TX queue size to minimum of %u\n",
+                           txq_entries);
+
+        return efx_realloc_channels(efx, ring->rx_pending, txq_entries);
 }
 
 static int efx_ethtool_set_pauseparam(struct net_device *net_dev,
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 9b225a7769f7..18713436b443 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -119,6 +119,25 @@ efx_max_tx_len(struct efx_nic *efx, dma_addr_t dma_addr)
         return len;
 }
 
+unsigned int efx_tx_max_skb_descs(struct efx_nic *efx)
+{
+        /* Header and payload descriptor for each output segment, plus
+         * one for every input fragment boundary within a segment
+         */
+        unsigned int max_descs = EFX_TSO_MAX_SEGS * 2 + MAX_SKB_FRAGS;
+
+        /* Possibly one more per segment for the alignment workaround */
+        if (EFX_WORKAROUND_5391(efx))
+                max_descs += EFX_TSO_MAX_SEGS;
+
+        /* Possibly more for PCIe page boundaries within input fragments */
+        if (PAGE_SIZE > EFX_PAGE_SIZE)
+                max_descs += max_t(unsigned int, MAX_SKB_FRAGS,
+                                   DIV_ROUND_UP(GSO_MAX_SIZE, EFX_PAGE_SIZE));
+
+        return max_descs;
+}
+
 /*
  * Add a socket buffer to a TX queue
  *