[PATCH v14 02/17] Add a new struct for device to manipulate external buffer.

xiaohui.xin
2010-11-04T09:04:58Z

Add a structure in structure net_device, the new field is
named as mp_port. It's for mediate passthru (zero-copy).
It contains the capability for the net device driver,
a socket, and an external buffer creator, external means
skb buffer belongs to the device may not be allocated from
kernel space.

Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
include/linux/netdevice.h | 25 ++++++++++++++++++++++++-
1 files changed, 24 insertions(+), 1 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 46c36ff..f6b1870 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -325,6 +325,28 @@ enum netdev_state_t {
__LINK_STATE_DORMANT,
};

+/*The structure for mediate passthru(zero-copy). */
+struct mp_port {
+ /* the header len */
+ int hdr_len;
+ /* the max payload len for one descriptor */
+ int data_len;
+ /* the pages for DMA in one time */
+ int npages;
+ /* the socket bind to */
+ struct socket *sock;
+ /* the header len for virtio-net */
+ int vnet_hlen;
+ /* the external buffer page creator */
+ struct skb_ext_page *(*ctor)(struct mp_port *,
+ struct sk_buff *, int);
+ /* the hash function attached to find according
+ * backend ring descriptor info for one external
+ * buffer page.
+ */
+ struct skb_ext_page *(*hash)(struct net_device *,
+ struct page *);
+};

/*
* This structure holds at boot time configured netdevice settings. They
@@ -1045,7 +1067,8 @@ struct net_device {

/* GARP */
struct garp_port *garp_port;
-
+ /* mpassthru */
+ struct mp_port *mp_port;
/* class/net/name entry */
struct device dev;
/* space for optional device, statistics, and wireless sysfs groups */
--
1.7.3