DCB: Add interface to query for the DCB capabilities of an device.

Adds to the netlink interface for Data Center Bridging (DCB), allowing
the DCB capabilities supported by a device to be queried.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 161 insertions, 1 deletions

diff --git a/drivers/net/ixgbe/ixgbe_dcb_nl.c b/drivers/net/ixgbe/ixgbe_dcb_nl.c
index 50bff2af6b04..eb3a6cea1aaa 100644
--- a/drivers/net/ixgbe/ixgbe_dcb_nl.c
+++ b/drivers/net/ixgbe/ixgbe_dcb_nl.c
@@ -337,6 +337,45 @@ static u8 ixgbe_dcbnl_set_all(struct net_device *netdev)
         return ret;
 }
 
+static u8 ixgbe_dcbnl_getcap(struct net_device *netdev, int capid, u8 *cap)
+{
+        struct ixgbe_adapter *adapter = netdev_priv(netdev);
+        u8 rval = 0;
+
+        if (adapter->flags & IXGBE_FLAG_DCB_ENABLED) {
+                switch (capid) {
+                case DCB_CAP_ATTR_PG:
+                        *cap = true;
+                        break;
+                case DCB_CAP_ATTR_PFC:
+                        *cap = true;
+                        break;
+                case DCB_CAP_ATTR_UP2TC:
+                        *cap = false;
+                        break;
+                case DCB_CAP_ATTR_PG_TCS:
+                        *cap = 0x80;
+                        break;
+                case DCB_CAP_ATTR_PFC_TCS:
+                        *cap = 0x80;
+                        break;
+                case DCB_CAP_ATTR_GSP:
+                        *cap = true;
+                        break;
+                case DCB_CAP_ATTR_BCN:
+                        *cap = false;
+                        break;
+                default:
+                        rval = -EINVAL;
+                        break;
+                }
+        } else {
+                rval = -EINVAL;
+        }
+
+        return rval;
+}
+
 struct dcbnl_rtnl_ops dcbnl_ops = {
         .getstate       = ixgbe_dcbnl_get_state,
         .setstate       = ixgbe_dcbnl_set_state,
@@ -351,6 +390,7 @@ struct dcbnl_rtnl_ops dcbnl_ops = {
         .getpgbwgcfgrx  = ixgbe_dcbnl_get_pg_bwg_cfg_rx,
         .setpfccfg      = ixgbe_dcbnl_set_pfc_cfg,
         .getpfccfg      = ixgbe_dcbnl_get_pfc_cfg,
-        .setall         = ixgbe_dcbnl_set_all
+        .setall         = ixgbe_dcbnl_set_all,
+        .getcap         = ixgbe_dcbnl_getcap
 };
 
diff --git a/include/linux/dcbnl.h b/include/linux/dcbnl.h
index 32d32c1ee410..13f0c638a695 100644
--- a/include/linux/dcbnl.h
+++ b/include/linux/dcbnl.h
@@ -43,6 +43,7 @@ struct dcbmsg {
  * @DCB_CMD_SET_ALL: apply all changes to the underlying device
  * @DCB_CMD_GPERM_HWADDR: get the permanent MAC address of the underlying
  *                        device.  Only useful when using bonding.
+ * @DCB_CMD_GCAP: request the DCB capabilities of the device
  */
 enum dcbnl_commands {
         DCB_CMD_UNDEFINED,
@@ -60,6 +61,7 @@ enum dcbnl_commands {
 
         DCB_CMD_SET_ALL,
         DCB_CMD_GPERM_HWADDR,
+        DCB_CMD_GCAP,
 
         __DCB_CMD_ENUM_MAX,
         DCB_CMD_MAX = __DCB_CMD_ENUM_MAX - 1,
@@ -78,6 +80,7 @@ enum dcbnl_commands {
  * @DCB_ATTR_PG_CFG: priority group configuration (NLA_NESTED)
  * @DCB_ATTR_SET_ALL: bool to commit changes to hardware or not (NLA_U8)
  * @DCB_ATTR_PERM_HWADDR: MAC address of the physical device (NLA_NESTED)
+ * @DCB_ATTR_CAP: DCB capabilities of the device (NLA_NESTED)
  */
 enum dcbnl_attrs {
         DCB_ATTR_UNDEFINED,
@@ -90,6 +93,7 @@ enum dcbnl_attrs {
         DCB_ATTR_PG_CFG,
         DCB_ATTR_SET_ALL,
         DCB_ATTR_PERM_HWADDR,
+        DCB_ATTR_CAP,
 
         __DCB_ATTR_ENUM_MAX,
         DCB_ATTR_MAX = __DCB_ATTR_ENUM_MAX - 1,
@@ -217,6 +221,39 @@ enum dcbnl_tc_attrs {
 };
 
 /**
+ * enum dcbnl_cap_attrs - DCB Capability attributes
+ *
+ * @DCB_CAP_ATTR_UNDEFINED: unspecified attribute to catch errors
+ * @DCB_CAP_ATTR_ALL: (NLA_FLAG) all capability parameters
+ * @DCB_CAP_ATTR_PG: (NLA_U8) device supports Priority Groups
+ * @DCB_CAP_ATTR_PFC: (NLA_U8) device supports Priority Flow Control
+ * @DCB_CAP_ATTR_UP2TC: (NLA_U8) device supports user priority to
+ *                               traffic class mapping
+ * @DCB_CAP_ATTR_PG_TCS: (NLA_U8) bitmap where each bit represents a
+ *                                number of traffic classes the device
+ *                                can be configured to use for Priority Groups
+ * @DCB_CAP_ATTR_PFC_TCS: (NLA_U8) bitmap where each bit represents a
+ *                                 number of traffic classes the device can be
+ *                                 configured to use for Priority Flow Control
+ * @DCB_CAP_ATTR_GSP: (NLA_U8) device supports group strict priority
+ * @DCB_CAP_ATTR_BCN: (NLA_U8) device supports Backwards Congestion
+ *                             Notification
+ */
+enum dcbnl_cap_attrs {
+        DCB_CAP_ATTR_UNDEFINED,
+        DCB_CAP_ATTR_ALL,
+        DCB_CAP_ATTR_PG,
+        DCB_CAP_ATTR_PFC,
+        DCB_CAP_ATTR_UP2TC,
+        DCB_CAP_ATTR_PG_TCS,
+        DCB_CAP_ATTR_PFC_TCS,
+        DCB_CAP_ATTR_GSP,
+        DCB_CAP_ATTR_BCN,
+
+        __DCB_CAP_ATTR_ENUM_MAX,
+        DCB_CAP_ATTR_MAX = __DCB_CAP_ATTR_ENUM_MAX - 1,
+};
+/**
  * enum dcb_general_attr_values - general DCB attribute values
  *
  * @DCB_ATTR_UNDEFINED: value used to indicate an attribute is not supported
diff --git a/include/net/dcbnl.h b/include/net/dcbnl.h
index 0ef0c5a46d8b..183ed040cf4c 100644
--- a/include/net/dcbnl.h
+++ b/include/net/dcbnl.h
@@ -39,6 +39,7 @@ struct dcbnl_rtnl_ops {
         void (*setpfccfg)(struct net_device *, int, u8);
         void (*getpfccfg)(struct net_device *, int, u8 *);
         u8   (*setall)(struct net_device *);
+        u8   (*getcap)(struct net_device *, int, u8 *);
 };
 
 #endif /* __NET_DCBNL_H__ */
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 516e8be83d72..de61d64d102d 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -61,6 +61,7 @@ static struct nla_policy dcbnl_rtnl_policy[DCB_ATTR_MAX + 1] = {
         [DCB_ATTR_PG_CFG]    = {.type = NLA_NESTED},
         [DCB_ATTR_SET_ALL]   = {.type = NLA_U8},
         [DCB_ATTR_PERM_HWADDR] = {.type = NLA_FLAG},
+        [DCB_ATTR_CAP]       = {.type = NLA_NESTED},
 };
 
 /* DCB priority flow control to User Priority nested attributes */
@@ -107,6 +108,17 @@ static struct nla_policy dcbnl_tc_param_nest[DCB_TC_ATTR_PARAM_MAX + 1] = {
         [DCB_TC_ATTR_PARAM_ALL]             = {.type = NLA_FLAG},
 };
 
+/* DCB capabilities nested attributes. */
+static struct nla_policy dcbnl_cap_nest[DCB_CAP_ATTR_MAX + 1] = {
+        [DCB_CAP_ATTR_ALL]     = {.type = NLA_FLAG},
+        [DCB_CAP_ATTR_PG]      = {.type = NLA_U8},
+        [DCB_CAP_ATTR_PFC]     = {.type = NLA_U8},
+        [DCB_CAP_ATTR_UP2TC]   = {.type = NLA_U8},
+        [DCB_CAP_ATTR_PG_TCS]  = {.type = NLA_U8},
+        [DCB_CAP_ATTR_PFC_TCS] = {.type = NLA_U8},
+        [DCB_CAP_ATTR_GSP]     = {.type = NLA_U8},
+        [DCB_CAP_ATTR_BCN]     = {.type = NLA_U8},
+};
 
 /* standard netlink reply call */
 static int dcbnl_reply(u8 value, u8 event, u8 cmd, u8 attr, u32 pid,
@@ -269,6 +281,72 @@ err_out:
         return -EINVAL;
 }
 
+static int dcbnl_getcap(struct net_device *netdev, struct nlattr **tb,
+                        u32 pid, u32 seq, u16 flags)
+{
+        struct sk_buff *dcbnl_skb;
+        struct nlmsghdr *nlh;
+        struct dcbmsg *dcb;
+        struct nlattr *data[DCB_CAP_ATTR_MAX + 1], *nest;
+        u8 value;
+        int ret = -EINVAL;
+        int i;
+        int getall = 0;
+
+        if (!tb[DCB_ATTR_CAP] || !netdev->dcbnl_ops->getcap)
+                return ret;
+
+        ret = nla_parse_nested(data, DCB_CAP_ATTR_MAX, tb[DCB_ATTR_CAP],
+                               dcbnl_cap_nest);
+        if (ret)
+                goto err_out;
+
+        dcbnl_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+        if (!dcbnl_skb)
+                goto err_out;
+
+        nlh = NLMSG_NEW(dcbnl_skb, pid, seq, RTM_GETDCB, sizeof(*dcb), flags);
+
+        dcb = NLMSG_DATA(nlh);
+        dcb->dcb_family = AF_UNSPEC;
+        dcb->cmd = DCB_CMD_GCAP;
+
+        nest = nla_nest_start(dcbnl_skb, DCB_ATTR_CAP);
+        if (!nest)
+                goto err;
+
+        if (data[DCB_CAP_ATTR_ALL])
+                getall = 1;
+
+        for (i = DCB_CAP_ATTR_ALL+1; i <= DCB_CAP_ATTR_MAX; i++) {
+                if (!getall && !data[i])
+                        continue;
+
+                if (!netdev->dcbnl_ops->getcap(netdev, i, &value)) {
+                        ret = nla_put_u8(dcbnl_skb, i, value);
+
+                        if (ret) {
+                                nla_nest_cancel(dcbnl_skb, nest);
+                                goto err;
+                        }
+                }
+        }
+        nla_nest_end(dcbnl_skb, nest);
+
+        nlmsg_end(dcbnl_skb, nlh);
+
+        ret = rtnl_unicast(dcbnl_skb, &init_net, pid);
+        if (ret)
+                goto err;
+
+        return 0;
+nlmsg_failure:
+err:
+        kfree(dcbnl_skb);
+err_out:
+        return -EINVAL;
+}
+
 static int __dcbnl_pg_getcfg(struct net_device *netdev, struct nlattr **tb,
                              u32 pid, u32 seq, u16 flags, int dir)
 {
@@ -675,6 +753,10 @@ static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
                 ret = dcbnl_pgrx_setcfg(netdev, tb, pid, nlh->nlmsg_seq,
                                         nlh->nlmsg_flags);
                 goto out;
+        case DCB_CMD_GCAP:
+                ret = dcbnl_getcap(netdev, tb, pid, nlh->nlmsg_seq,
+                                   nlh->nlmsg_flags);
+                goto out;
         default:
                 goto errout;
         }