dcbnl: adding DCBX engine capability

Adding an optional DCBX capability and a pair for get-set routines for
setting the device DCBX mode. The DCBX capability is a bit field of
supported attributes. The user is expected to set the DCBX mode with a
subset of the advertised attributes.

This patch is dependent on the following patches:
[net-next-2.6 PATCH 1/3] dcbnl: add support for ieee8021Qaz attributes
[net-next-2.6 PATCH 2/3] dcbnl: add appliction tlv handlers
[net-next-2.6 PATCH 3/3] net_dcb: add application notifiers

Signed-off-by: Shmulik Ravid <shmulikr@broadcom.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/dcbnl.h b/include/linux/dcbnl.h
index 775bdb4..16eea36 100644
--- a/include/linux/dcbnl.h
+++ b/include/linux/dcbnl.h
@@ -135,6 +135,8 @@
  * @DCB_CMD_SAPP: set application protocol configuration
  * @DCB_CMD_IEEE_SET: set IEEE 802.1Qaz configuration
  * @DCB_CMD_IEEE_GET: get IEEE 802.1Qaz configuration
+ * @DCB_CMD_GDCBX: get DCBX engine configuration
+ * @DCB_CMD_SDCBX: set DCBX engine configuration
  */
 enum dcbnl_commands {
 	DCB_CMD_UNDEFINED,
@@ -171,6 +173,9 @@
 	DCB_CMD_IEEE_SET,
 	DCB_CMD_IEEE_GET,
 
+	DCB_CMD_GDCBX,
+	DCB_CMD_SDCBX,
+
 	__DCB_CMD_ENUM_MAX,
 	DCB_CMD_MAX = __DCB_CMD_ENUM_MAX - 1,
 };
@@ -191,6 +196,7 @@
  * @DCB_ATTR_NUMTCS: number of traffic classes supported (NLA_NESTED)
  * @DCB_ATTR_BCN: backward congestion notification configuration (NLA_NESTED)
  * @DCB_ATTR_IEEE: IEEE 802.1Qaz supported attributes (NLA_NESTED)
+ * @DCB_ATTR_DCBX: DCBX engine configuration in the device (NLA_U8)
  */
 enum dcbnl_attrs {
 	DCB_ATTR_UNDEFINED,
@@ -211,6 +217,8 @@
 	/* IEEE std attributes */
 	DCB_ATTR_IEEE,
 
+	DCB_ATTR_DCBX,
+
 	__DCB_ATTR_ENUM_MAX,
 	DCB_ATTR_MAX = __DCB_ATTR_ENUM_MAX - 1,
 };
@@ -370,6 +378,8 @@
  * @DCB_CAP_ATTR_GSP: (NLA_U8) device supports group strict priority
  * @DCB_CAP_ATTR_BCN: (NLA_U8) device supports Backwards Congestion
  *                             Notification
+ * @DCB_CAP_ATTR_DCBX: (NLA_U8) device supports DCBX engine
+ *
  */
 enum dcbnl_cap_attrs {
 	DCB_CAP_ATTR_UNDEFINED,
@@ -381,12 +391,45 @@
 	DCB_CAP_ATTR_PFC_TCS,
 	DCB_CAP_ATTR_GSP,
 	DCB_CAP_ATTR_BCN,
+	DCB_CAP_ATTR_DCBX,
 
 	__DCB_CAP_ATTR_ENUM_MAX,
 	DCB_CAP_ATTR_MAX = __DCB_CAP_ATTR_ENUM_MAX - 1,
 };
 
 /**
+ * DCBX capability flags
+ *
+ * @DCB_CAP_DCBX_HOST: DCBX negotiation is performed by the host LLDP agent.
+ *                     'set' routines are used to configure the device with
+ *                     the negotiated parameters
+ *
+ * @DCB_CAP_DCBX_LLD_MANAGED: DCBX negotiation is not performed in the host but
+ *                            by another entity
+ *                            'get' routines are used to retrieve the
+ *                            negotiated parameters
+ *                            'set' routines can be used to set the initial
+ *                            negotiation configuration
+ *
+ * @DCB_CAP_DCBX_VER_CEE: for a non-host DCBX engine, indicates the engine
+ *                        supports the CEE protocol flavor
+ *
+ * @DCB_CAP_DCBX_VER_IEEE: for a non-host DCBX engine, indicates the engine
+ *                         supports the IEEE protocol flavor
+ *
+ * @DCB_CAP_DCBX_STATIC: for a non-host DCBX engine, indicates the engine
+ *                       supports static configuration (i.e no actual
+ *                       negotiation is performed negotiated parameters equal
+ *                       the initial configuration)
+ *
+ */
+#define DCB_CAP_DCBX_HOST		0x01
+#define DCB_CAP_DCBX_LLD_MANAGED	0x02
+#define DCB_CAP_DCBX_VER_CEE		0x04
+#define DCB_CAP_DCBX_VER_IEEE		0x08
+#define DCB_CAP_DCBX_STATIC		0x10
+
+/**
  * enum dcbnl_numtcs_attrs - number of traffic classes
  *
  * @DCB_NUMTCS_ATTR_UNDEFINED: unspecified attribute to catch errors