[PATCH net-next 09/14] sfc: factor out efx_tx_tso_header_length() and understand encapsulation

[Edward Cree]

ef100 will need to check this against NIC limits.

Signed-off-by: Edward Cree <ec...@solarflare.com>
---
 drivers/net/ethernet/sfc/tx_common.c | 17 +++++++++++++++--
 drivers/net/ethernet/sfc/tx_common.h |  1 +
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/sfc/tx_common.c 
b/drivers/net/ethernet/sfc/tx_common.c
index 6ac19daa891a..2a058b76d1f0 100644
--- a/drivers/net/ethernet/sfc/tx_common.c
+++ b/drivers/net/ethernet/sfc/tx_common.c
@@ -311,6 +311,20 @@ struct efx_tx_buffer *efx_tx_map_chunk(struct efx_tx_queue 
*tx_queue,
        return buffer;
 }
 
+int efx_tx_tso_header_length(struct sk_buff *skb)
+{
+       size_t header_len;
+
+       if (skb->encapsulation)
+               header_len = skb_inner_transport_header(skb) -
+                               skb->data +
+                               (inner_tcp_hdr(skb)->doff << 2u);
+       else
+               header_len = skb_transport_header(skb) - skb->data +
+                               (tcp_hdr(skb)->doff << 2u);
+       return header_len;
+}
+
 /* Map all data from an SKB for DMA and create descriptors on the queue. */
 int efx_tx_map_data(struct efx_tx_queue *tx_queue, struct sk_buff *skb,
                    unsigned int segment_count)
@@ -339,8 +353,7 @@ int efx_tx_map_data(struct efx_tx_queue *tx_queue, struct 
sk_buff *skb,
                /* For TSO we need to put the header in to a separate
                 * descriptor. Map this separately if necessary.
                 */
-               size_t header_len = skb_transport_header(skb) - skb->data +
-                               (tcp_hdr(skb)->doff << 2u);
+               size_t header_len = efx_tx_tso_header_length(skb);
 
                if (header_len != len) {
                        tx_queue->tso_long_headers++;
diff --git a/drivers/net/ethernet/sfc/tx_common.h 
b/drivers/net/ethernet/sfc/tx_common.h
index 82e2e291317d..cbe995b024a6 100644
--- a/drivers/net/ethernet/sfc/tx_common.h
+++ b/drivers/net/ethernet/sfc/tx_common.h
@@ -34,6 +34,7 @@ void efx_enqueue_unwind(struct efx_tx_queue *tx_queue,
 
 struct efx_tx_buffer *efx_tx_map_chunk(struct efx_tx_queue *tx_queue,
                                       dma_addr_t dma_addr, size_t len);
+int efx_tx_tso_header_length(struct sk_buff *skb);
 int efx_tx_map_data(struct efx_tx_queue *tx_queue, struct sk_buff *skb,
                    unsigned int segment_count);