net/dcb: Add an optional max rate attribute

Although not specified in 8021Qaz spec, it could be useful to enable drivers
whose HW supports setting a rate limit for an ETS TC. This patch adds this
optional attribute to DCB netlink. To use it, drivers should implement and
register the callbacks ieee_setmaxrate and ieee_getmaxrate. The units are 64
bits long and specified in Kbps to enable usage over both slow and very fast
networks.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/dcbnl.h b/include/linux/dcbnl.h
index 65a2562..6bb4338 100644 (file)
--- a/include/linux/dcbnl.h
+++ b/include/linux/dcbnl.h
@@ -67,6 +67,17 @@ struct ieee_ets {
        __u8    reco_prio_tc[IEEE_8021QAZ_MAX_TCS];
 };
 
+/* This structure contains rate limit extension to the IEEE 802.1Qaz ETS
+ * managed object.
+ * Values are 64 bits long and specified in Kbps to enable usage over both
+ * slow and very fast networks.
+ *
+ * @tc_maxrate: maximal tc tx bandwidth indexed by traffic class
+ */
+struct ieee_maxrate {
+       __u64   tc_maxrate[IEEE_8021QAZ_MAX_TCS];
+};
+
 /* This structure contains the IEEE 802.1Qaz PFC managed object
  *
  * @pfc_cap: Indicates the number of traffic classes on the local device
@@ -321,6 +332,7 @@ enum ieee_attrs {
        DCB_ATTR_IEEE_PEER_ETS,
        DCB_ATTR_IEEE_PEER_PFC,
        DCB_ATTR_IEEE_PEER_APP,
+       DCB_ATTR_IEEE_MAXRATE,
        __DCB_ATTR_IEEE_MAX
 };
 #define DCB_ATTR_IEEE_MAX (__DCB_ATTR_IEEE_MAX - 1)

diff --git a/include/net/dcbnl.h b/include/net/dcbnl.h
index f55c980..fc5d5dc 100644 (file)
--- a/include/net/dcbnl.h
+++ b/include/net/dcbnl.h
@@ -48,6 +48,8 @@ struct dcbnl_rtnl_ops {
        /* IEEE 802.1Qaz std */
        int (*ieee_getets) (struct net_device *, struct ieee_ets *);
        int (*ieee_setets) (struct net_device *, struct ieee_ets *);
+       int (*ieee_getmaxrate) (struct net_device *, struct ieee_maxrate *);
+       int (*ieee_setmaxrate) (struct net_device *, struct ieee_maxrate *);
        int (*ieee_getpfc) (struct net_device *, struct ieee_pfc *);
        int (*ieee_setpfc) (struct net_device *, struct ieee_pfc *);
        int (*ieee_getapp) (struct net_device *, struct dcb_app *);

diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 36f37af..8dfa1da 100644 (file)
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -178,6 +178,7 @@ static const struct nla_policy dcbnl_ieee_policy[DCB_ATTR_IEEE_MAX + 1] = {
        [DCB_ATTR_IEEE_ETS]         = {.len = sizeof(struct ieee_ets)},
        [DCB_ATTR_IEEE_PFC]         = {.len = sizeof(struct ieee_pfc)},
        [DCB_ATTR_IEEE_APP_TABLE]   = {.type = NLA_NESTED},
+       [DCB_ATTR_IEEE_MAXRATE]   = {.len = sizeof(struct ieee_maxrate)},
 };
 
 static const struct nla_policy dcbnl_ieee_app[DCB_ATTR_IEEE_APP_MAX + 1] = {
@@ -1246,6 +1247,17 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
                        goto nla_put_failure;
        }
 
+       if (ops->ieee_getmaxrate) {
+               struct ieee_maxrate maxrate;
+               err = ops->ieee_getmaxrate(netdev, &maxrate);
+               if (!err) {
+                       err = nla_put(skb, DCB_ATTR_IEEE_MAXRATE,
+                                     sizeof(maxrate), &maxrate);
+                       if (err)
+                               goto nla_put_failure;
+               }
+       }
+
        if (ops->ieee_getpfc) {
                struct ieee_pfc pfc;
                err = ops->ieee_getpfc(netdev, &pfc);
@@ -1601,6 +1613,14 @@ static int dcbnl_ieee_set(struct net_device *netdev, struct nlattr **tb,
                        goto err;
        }
 
+       if (ieee[DCB_ATTR_IEEE_MAXRATE] && ops->ieee_setmaxrate) {
+               struct ieee_maxrate *maxrate =
+                       nla_data(ieee[DCB_ATTR_IEEE_MAXRATE]);
+               err = ops->ieee_setmaxrate(netdev, maxrate);
+               if (err)
+                       goto err;
+       }
+
        if (ieee[DCB_ATTR_IEEE_PFC] && ops->ieee_setpfc) {
                struct ieee_pfc *pfc = nla_data(ieee[DCB_ATTR_IEEE_PFC]);
                err = ops->ieee_setpfc(netdev, pfc);