5 files changed, 51 insertions, 9 deletions

diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c
index 7d1651b..be3cade 100644
--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -1383,6 +1383,11 @@ 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_channels(efx);
 	if (rc)
@@ -1942,6 +1947,7 @@ 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;
 
 	/* Clear MAC statistics */
 	efx->mac_op->update_stats(efx);
diff --git a/drivers/net/sfc/efx.h b/drivers/net/sfc/efx.h
index b0d1209..a5d1c60 100644
--- a/drivers/net/sfc/efx.h
+++ b/drivers/net/sfc/efx.h
@@ -38,6 +38,7 @@ 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);
@@ -60,10 +61,15 @@ 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/sfc/ethtool.c b/drivers/net/sfc/ethtool.c
index d229027..cfaf801 100644
--- a/drivers/net/sfc/ethtool.c
+++ b/drivers/net/sfc/ethtool.c
@@ -677,21 +677,27 @@ 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/sfc/nic.h b/drivers/net/sfc/nic.h
index 7443f99..d2405ce 100644
--- a/drivers/net/sfc/nic.h
+++ b/drivers/net/sfc/nic.h
@@ -65,6 +65,11 @@ enum {
 #define FALCON_GMAC_LOOPBACKS			\
 	(1 << LOOPBACK_GMAC)
 
+/* Alignment of PCIe DMA boundaries (4KB) */
+#define EFX_PAGE_SIZE	4096
+/* Size and alignment of buffer table entries (same) */
+#define EFX_BUF_SIZE	EFX_PAGE_SIZE
+
 /**
  * struct falcon_board_type - board operations and type information
  * @id: Board type id, as found in NVRAM
diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c
index 84eb99e..6d3b68a 100644
--- a/drivers/net/sfc/tx.c
+++ b/drivers/net/sfc/tx.c
@@ -115,6 +115,25 @@ 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
  *