Implement TSO for 82550/82551 controllers.

 o Configure controller to use dynamic TBD as TSO requires that
   operation mode.
 o Add a dummy TBD to tx_cb_u as TSO can access one more TBD in TSO
   operation.
 o Increase a DMA segment size to 4096 to hold a full IP segment
   with link layer header.
 o Unlike other TSO capable controllers, 82550/82551 does not
   modify the first IP packet in TSO operation so driver should
   create an IP packet with proper header. Subsequent IP packets
   are generated from the header information in the first IP packet
   header. Likewise pseudo checksum also should be computed by
   driver for the first packet.
 o TSO requires one more TBD to hold total TCP payload. To make
   code simple for TSO/non-TSO case, increase the index of the
   first available TBD array.
 o Remove KASSERT that checks the size of a DMA segment should be
   less than or equal to MCLBYTES as it's no longer valid in TSO.
 o Tx threshold and number of TBDs field is used to store MSS in
   TSO. So don't set the Tx threshold in TSO case.

1 files changed, 1 insertions, 1 deletions

diff --git a/sys/dev/fxp/if_fxpreg.h b/sys/dev/fxp/if_fxpreg.h
index 26edfbd..982d2f0 100644
--- a/sys/dev/fxp/if_fxpreg.h
+++ b/sys/dev/fxp/if_fxpreg.h
@@ -292,7 +292,7 @@ struct fxp_cb_tx {
 	 */
 	union {
 		struct fxp_ipcb ipcb;
-		struct fxp_tbd tbd[FXP_NTXSEG];
+		struct fxp_tbd tbd[FXP_NTXSEG + 1];
 	} tx_cb_u;
 };