[eoib] Add Ethernet over Infiniband (EoIB) driver

EoIB is a fairly simple protocol in which raw Ethernet frames
(excluding the CRC) are encapsulated within Infiniband Unreliable
Datagrams, with a four-byte fixed EoIB header (which conveys no actual
information).  The Ethernet broadcast domain is provided by a
multicast group, similar to the IPoIB IPv4 multicast group.

The mapping from Ethernet MAC addresses to Infiniband address vectors
is achieved by snooping incoming traffic and building a peer cache
which can then be used to map a MAC address into a port GID.  The
address vector is completed using a path record lookup, as for IPoIB.
Note that this requires every packet to include a GRH.

Add basic support for EoIB devices.  This driver is substantially
derived from the IPoIB driver.  There is currently no mechanism for
automatically creating EoIB devices.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/eoib.h

@@ -0,0 +1,60 @@
+#ifndef _IPXE_EOIB_H
+#define _IPXE_EOIB_H
+
+/** @file
+ *
+ * Ethernet over Infiniband
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <byteswap.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/infiniband.h>
+#include <ipxe/ib_mcast.h>
+
+/** An EoIB header */
+struct eoib_header {
+	/** Signature */
+	uint16_t magic;
+	/** Reserved */
+	uint16_t reserved;
+} __attribute__ (( packed ));
+
+/** EoIB magic signature */
+#define EOIB_MAGIC 0x8919
+
+/** An EoIB device */
+struct eoib_device {
+	/** Name */
+	const char *name;
+	/** Network device */
+	struct net_device *netdev;
+	/** Underlying Infiniband device */
+	struct ib_device *ibdev;
+	/** List of EoIB devices */
+	struct list_head list;
+	/** Broadcast address */
+	struct ib_address_vector broadcast;
+
+	/** Completion queue */
+	struct ib_completion_queue *cq;
+	/** Queue pair */
+	struct ib_queue_pair *qp;
+	/** Broadcast group membership */
+	struct ib_mc_membership membership;
+
+	/** Peer cache */
+	struct list_head peers;
+};
+
+extern int eoib_create ( struct ib_device *ibdev, const uint8_t *hw_addr,
+			 struct ib_address_vector *broadcast,
+			 const char *name );
+extern struct eoib_device * eoib_find ( struct ib_device *ibdev,
+					const uint8_t *hw_addr );
+extern void eoib_destroy ( struct eoib_device *eoib );
+
+#endif /* _IPXE_EOIB_H */

src/include/ipxe/errfile.h

@@ -185,6 +185,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #define ERRFILE_intelxvf	     ( ERRFILE_DRIVER | 0x00790000 )
 #define ERRFILE_smsc95xx	     ( ERRFILE_DRIVER | 0x007a0000 )
 #define ERRFILE_acm		     ( ERRFILE_DRIVER | 0x007b0000 )
+#define ERRFILE_eoib		     ( ERRFILE_DRIVER | 0x007c0000 )
 
 #define ERRFILE_aoe			( ERRFILE_NET | 0x00000000 )
 #define ERRFILE_arp			( ERRFILE_NET | 0x00010000 )