Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752001Ab1EDHzY (ORCPT ); Wed, 4 May 2011 03:55:24 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:47568 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751850Ab1EDHzV (ORCPT ); Wed, 4 May 2011 03:55:21 -0400 Subject: [PATCH V4 2/8] netdevice.h: Add a new zerocopy device flag From: Shirley Ma To: David Miller , mst@redhat.com, Eric Dumazet , Avi Kivity , Arnd Bergmann Cc: netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Date: Wed, 04 May 2011 00:55:17 -0700 Message-ID: <1304495717.20660.67.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 (2.28.3-1.fc12) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1211 Lines: 34 Signed-off-by: Shirley Ma --- include/linux/netdevice.h | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 0249fe7..0808f1e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1067,6 +1067,16 @@ struct net_device { #define NETIF_F_RXHASH (1 << 28) /* Receive hashing offload */ #define NETIF_F_RXCSUM (1 << 29) /* Receive checksumming offload */ +/* + * Bit 31 is for device to map userspace buffers -- zerocopy + * Device can set this flag when it supports HIGHDMA. + * Device can't recycle this kind of skb buffers. + * There are 256 bytes copied, the rest of buffers are mapped. + * The userspace callback should only be called when last reference to this skb + * is gone. + */ +#define NETIF_F_ZEROCOPY (1 << 31) + /* Segmentation offload features */ #define NETIF_F_GSO_SHIFT 16 #define NETIF_F_GSO_MASK 0x00ff0000 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/