IB/ipath: Allow receive ports mapped into userspace to be shared

Improve port-sharing performance by allowing any process to receive
packets from the shared hardware port under a spin lock for mutual
exclusion. Previously, one process was nominated as the master and
that process was responsible for receiving all packets from the shared
hardware port and either consuming them or forwarding them to their
destination. This led to starvation problems for other processes when
the master process was busy in computation phases.
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_common.h

 /*
- * Copyright (c) 2006 QLogic, Inc. All rights reserved.
+ * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
  * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
  *
  * This software is available to you under a choice of one of two
@@ -318,11 +318,17 @@ struct ipath_base_info {
 	/* address of readonly memory copy of the rcvhdrq tail register. */
 	__u64 spi_rcvhdr_tailaddr;
 
-	/* shared memory pages for subports if IPATH_RUNTIME_MASTER is set */
+	/* shared memory pages for subports if port is shared */
 	__u64 spi_subport_uregbase;
 	__u64 spi_subport_rcvegrbuf;
 	__u64 spi_subport_rcvhdr_base;
 
+	/* shared memory page for hardware port if it is shared */
+	__u64 spi_port_uregbase;
+	__u64 spi_port_rcvegrbuf;
+	__u64 spi_port_rcvhdr_base;
+	__u64 spi_port_rcvhdr_tailaddr;
+
 } __attribute__ ((aligned(8)));
 
 
@@ -346,7 +352,7 @@ struct ipath_base_info {
  * may not be implemented; the user code must deal with this if it
  * cares, or it must abort after initialization reports the difference.
  */
-#define IPATH_USER_SWMINOR 3
+#define IPATH_USER_SWMINOR 4
 
 #define IPATH_USER_SWVERSION ((IPATH_USER_SWMAJOR<<16) | IPATH_USER_SWMINOR)
 
@@ -420,7 +426,7 @@ struct ipath_user_info {
 #define IPATH_CMD_TID_UPDATE	19	/* update expected TID entries */
 #define IPATH_CMD_TID_FREE	20	/* free expected TID entries */
 #define IPATH_CMD_SET_PART_KEY	21	/* add partition key */
-#define IPATH_CMD_SLAVE_INFO	22	/* return info on slave processes */
+#define __IPATH_CMD_SLAVE_INFO	22	/* return info on slave processes (for old user code) */
 #define IPATH_CMD_ASSIGN_PORT	23	/* allocate HCA and port */
 #define IPATH_CMD_USER_INIT 	24	/* set up userspace */
 
@@ -432,7 +438,7 @@ struct ipath_port_info {
 	__u16 port;		/* port on unit assigned to caller */
 	__u16 subport;		/* subport on unit assigned to caller */
 	__u16 num_ports;	/* number of ports available on unit */
-	__u16 num_subports;	/* number of subport slaves opened on port */
+	__u16 num_subports;	/* number of subports opened on port */
 };
 
 struct ipath_tid_info {