[infiniband] Split subnet management agent client out into ib_smc.c

Not all Infiniband cards have embedded subnet management agents.
Split out the code that communicates with such an embedded SMA into a
separate ib_smc.c file, and have drivers call ib_smc_update()
explicitly when they suspect that the answers given by the embedded
SMA may have changed.

src/include/gpxe/ib_packet.h

@@ -0,0 +1,114 @@
+#ifndef _GPXE_IB_PACKET_H
+#define _GPXE_IB_PACKET_H
+
+/** @file
+ *
+ * Infiniband packet format
+ *
+ */
+
+/** Half of an Infiniband Global Identifier */
+struct ib_gid_half {
+	uint8_t bytes[8];
+};
+
+/** An Infiniband Global Identifier */
+struct ib_gid {
+	union {
+		uint8_t bytes[16];
+		uint16_t words[8];
+		uint32_t dwords[4];
+		struct ib_gid_half half[2];
+	} u;
+};
+
+/** An Infiniband Local Route Header */
+struct ib_local_route_header {
+	/** Virtual lane and link version */
+	uint8_t vl__lver;
+	/** Service level and next link header */
+	uint8_t sl__lnh;
+	/** Destination LID */
+	uint16_t dlid;
+	/** Packet length */
+	uint16_t length;
+	/** Source LID */
+	uint16_t slid;
+} __attribute__ (( packed ));
+
+/** Infiniband virtual lanes */
+enum ib_vl {
+	IB_VL_DEFAULT = 0,
+	IB_VL_SMP = 15,
+};
+
+/** An Infiniband Link Next Header value */
+enum ib_lnh {
+	IB_LNH_RAW = 0,
+	IB_LNH_IPv6 = 1,
+	IB_LNH_BTH = 2,
+	IB_LNH_GRH = 3
+};
+
+/** Default Infiniband LID */
+#define IB_LID_NONE 0xffff
+
+/** An Infiniband Global Route Header */
+struct ib_global_route_header {
+	/** IP version, traffic class, and flow label
+	 *
+	 *  4 bits : Version of the GRH
+	 *  8 bits : Traffic class
+	 * 20 bits : Flow label
+	 */
+	uint32_t ipver__tclass__flowlabel;
+	/** Payload length */
+	uint16_t paylen;
+	/** Next header */
+	uint8_t nxthdr;
+	/** Hop limit */
+	uint8_t hoplmt;
+	/** Source GID */
+	struct ib_gid sgid;
+	/** Destiniation GID */
+	struct ib_gid dgid;
+} __attribute__ (( packed ));
+
+#define IB_GRH_IPVER_IPv6 0x06
+#define IB_GRH_NXTHDR_IBA 0x1b
+#define IB_GRH_HOPLMT_MAX 0xff
+
+/** An Infiniband Base Transport Header */
+struct ib_base_transport_header {
+	/** Opcode */
+	uint8_t opcode;
+	/** Transport header version, pad count, migration and solicitation */
+	uint8_t se__m__padcnt__tver;
+	/** Partition key */
+	uint16_t pkey;
+	/** Destination queue pair */
+	uint32_t dest_qp;
+	/** Packet sequence number and acknowledge request */
+	uint32_t ack__psn;
+} __attribute__ (( packed ));
+
+/** An Infiniband BTH opcode */
+enum ib_bth_opcode {
+	BTH_OPCODE_UD_SEND = 0x64,
+};
+
+/** Default Infiniband partition key */
+#define IB_PKEY_NONE 0xffff
+
+/** Subnet management queue pair number */
+#define IB_QPN_SMP 0
+
+/** An Infiniband Datagram Extended Transport Header */
+struct ib_datagram_extended_transport_header {
+	/** Queue key */
+	uint32_t qkey;
+	/** Source queue pair */
+	uint32_t src_qp;
+} __attribute__ (( packed ));
+
+#endif /* _GPXE_IB_PACKET_H */