net: Enable 64-bit net device statistics on 32-bit architectures

Use struct rtnl_link_stats64 as the statistics structure.

On 32-bit architectures, insert 32 bits of padding after/before each
field of struct net_device_stats to make its layout compatible with
struct rtnl_link_stats64.  Add an anonymous union in net_device; move
stats into the union and add struct rtnl_link_stats64 stats64.

Add net_device_ops::ndo_get_stats64, implementations of which will
return a pointer to struct rtnl_link_stats64.  Drivers that implement
this operation must not update the structure asynchronously.

Change dev_get_stats() to call ndo_get_stats64 if available, and to
return a pointer to struct rtnl_link_stats64.  Change callers of
dev_get_stats() accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index 85c812db5a3f..7fcad2e1be3d 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -4,7 +4,7 @@
 #include <linux/types.h>
 #include <linux/netlink.h>
 
-/* The struct should be in sync with struct net_device_stats */
+/* This struct should be in sync with struct rtnl_link_stats64 */
 struct rtnl_link_stats {
         __u32   rx_packets;             /* total packets received       */
         __u32   tx_packets;             /* total packets transmitted    */
@@ -37,6 +37,7 @@ struct rtnl_link_stats {
         __u32   tx_compressed;
 };
 
+/* The main device statistics structure */
 struct rtnl_link_stats64 {
         __u64   rx_packets;             /* total packets received       */
         __u64   tx_packets;             /* total packets transmitted    */