[infiniband] Add a "communication-managed reliable connection" protocol

SRP over Infiniband uses a protocol whereby data is sent via a
combination of the CM private data fields and the RC queue pair
itself.  This seems sufficiently generic that it's worth having
available as a separate protocol.

src/include/gpxe/errfile.h

@@ -153,6 +153,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define ERRFILE_ib_cm			( ERRFILE_NET | 0x001e0000 )
 #define ERRFILE_net80211		( ERRFILE_NET | 0x001f0000 )
 #define ERRFILE_ib_mi			( ERRFILE_NET | 0x00200000 )
+#define ERRFILE_ib_cmrc			( ERRFILE_NET | 0x00210000 )
 
 #define ERRFILE_image		      ( ERRFILE_IMAGE | 0x00000000 )
 #define ERRFILE_elf		      ( ERRFILE_IMAGE | 0x00010000 )

src/include/gpxe/ib_cmrc.h

@@ -0,0 +1,20 @@
+#ifndef _GPXE_IB_CMRC_H
+#define _GPXE_IB_CMRC_H
+
+/** @file
+ *
+ * Infiniband Communication-managed Reliable Connections
+ *
+ */
+
+FILE_LICENCE ( BSD2 );
+
+#include <gpxe/infiniband.h>
+#include <gpxe/xfer.h>
+
+extern int ib_cmrc_open ( struct xfer_interface *xfer,
+			  struct ib_device *ibdev,
+			  struct ib_gid *dgid,
+			  struct ib_gid_half *service_id );
+
+#endif /* _GPXE_IB_CMRC_H */

src/net/infiniband/ib_cmrc.c

@@ -0,0 +1,435 @@
+/*
+ * Copyright (C) 2009 Fen Systems Ltd <mbrown@fensystems.co.uk>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ *   Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in
+ *   the documentation and/or other materials provided with the
+ *   distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+FILE_LICENCE ( BSD2 );
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <gpxe/iobuf.h>
+#include <gpxe/xfer.h>
+#include <gpxe/process.h>
+#include <gpxe/infiniband.h>
+#include <gpxe/ib_cm.h>
+#include <gpxe/ib_cmrc.h>
+
+/**
+ * @file
+ *
+ * Infiniband Communication-managed Reliable Connections
+ *
+ */
+
+/** CMRC number of send WQEs
+ *
+ * This is a policy decision.
+ */
+#define IB_CMRC_NUM_SEND_WQES 4
+
+/** CMRC number of receive WQEs
+ *
+ * This is a policy decision.
+ */
+#define IB_CMRC_NUM_RECV_WQES 2
+
+/** CMRC number of completion queue entries
+ *
+ * This is a policy decision
+ */
+#define IB_CMRC_NUM_CQES 8
+
+/** An Infiniband Communication-Managed Reliable Connection */
+struct ib_cmrc_connection {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** Data transfer interface */
+	struct xfer_interface xfer;
+	/** Infiniband device */
+	struct ib_device *ibdev;
+	/** Completion queue */
+	struct ib_completion_queue *cq;
+	/** Queue pair */
+	struct ib_queue_pair *qp;
+	/** Connection */
+	struct ib_connection *conn;
+	/** Destination GID */
+	struct ib_gid dgid;
+	/** Service ID */
+	struct ib_gid_half service_id;
+	/** QP is connected */
+	int connected;
+	/** Shutdown process */
+	struct process shutdown;
+};
+
+/**
+ * Shut down CMRC connection gracefully
+ *
+ * @v process		Process
+ *
+ * The Infiniband data structures are not reference-counted or
+ * guarded.  It is therefore unsafe to shut them down while we may be
+ * in the middle of a callback from the Infiniband stack (e.g. in a
+ * receive completion handler).
+ *
+ * This shutdown process will run some time after the call to
+ * ib_cmrc_close(), after control has returned out of the Infiniband
+ * core, and will shut down the Infiniband interfaces cleanly.
+ *
+ * The shutdown process holds an implicit reference on the CMRC
+ * connection, ensuring that the structure is not freed before the
+ * shutdown process has run.
+ */
+static void ib_cmrc_shutdown ( struct process *process ) {
+	struct ib_cmrc_connection *cmrc =
+		container_of ( process, struct ib_cmrc_connection, shutdown );
+
+	DBGC ( cmrc, "CMRC %p shutting down\n", cmrc );
+
+	/* Shut down Infiniband interface */
+	ib_destroy_conn ( cmrc->ibdev, cmrc->qp, cmrc->conn );
+	ib_destroy_qp ( cmrc->ibdev, cmrc->qp );
+	ib_destroy_cq ( cmrc->ibdev, cmrc->cq );
+	ib_close ( cmrc->ibdev );
+
+	/* Remove process from run queue */
+	process_del ( &cmrc->shutdown );
+
+	/* Drop the remaining reference */
+	ref_put ( &cmrc->refcnt );
+}
+
+/**
+ * Close CMRC connection
+ *
+ * @v cmrc		Communication-Managed Reliable Connection
+ * @v rc		Reason for close
+ */
+static void ib_cmrc_close ( struct ib_cmrc_connection *cmrc, int rc ) {
+
+	/* Close data transfer interface */
+	xfer_nullify ( &cmrc->xfer );
+	xfer_close ( &cmrc->xfer, rc );
+
+	/* Schedule shutdown process */
+	process_add ( &cmrc->shutdown );
+}
+
+/**
+ * Handle change of CMRC connection status
+ *
+ * @v ibdev		Infiniband device
+ * @v qp		Queue pair
+ * @v conn		Connection
+ * @v rc_cm		Connection status code
+ * @v private_data	Private data, if available
+ * @v private_data_len	Length of private data
+ */
+static void ib_cmrc_changed ( struct ib_device *ibdev __unused,
+			      struct ib_queue_pair *qp,
+			      struct ib_connection *conn __unused, int rc_cm,
+			      void *private_data, size_t private_data_len ) {
+	struct ib_cmrc_connection *cmrc = ib_qp_get_ownerdata ( qp );
+	int rc_xfer;
+
+	/* Record connection status */
+	if ( rc_cm == 0 ) {
+		DBGC ( cmrc, "CMRC %p connected\n", cmrc );
+		cmrc->connected = 1;
+	} else {
+		DBGC ( cmrc, "CMRC %p disconnected: %s\n",
+		       cmrc, strerror ( rc_cm ) );
+		cmrc->connected = 0;
+	}
+
+	/* Pass up any private data */
+	DBGC2 ( cmrc, "CMRC %p received private data:\n", cmrc );
+	DBGC2_HDA ( cmrc, 0, private_data, private_data_len );
+	if ( ( rc_xfer = xfer_deliver_raw ( &cmrc->xfer, private_data,
+					    private_data_len ) ) != 0 ) {
+		DBGC ( cmrc, "CMRC %p could not deliver private data: %s\n",
+		       cmrc, strerror ( rc_xfer ) );
+		ib_cmrc_close ( cmrc, rc_xfer );
+		return;
+	}
+
+	/* If we are disconnected, close the upper connection */
+	if ( rc_cm != 0 ) {
+		ib_cmrc_close ( cmrc, rc_cm );
+		return;
+	}
+}
+
+/** CMRC connection operations */
+static struct ib_connection_operations ib_cmrc_conn_op = {
+	.changed = ib_cmrc_changed,
+};
+
+/**
+ * Handle CMRC send completion
+ *
+ * @v ibdev		Infiniband device
+ * @v qp		Queue pair
+ * @v iobuf		I/O buffer
+ * @v rc		Completion status code
+ */
+static void ib_cmrc_complete_send ( struct ib_device *ibdev __unused,
+				    struct ib_queue_pair *qp,
+				    struct io_buffer *iobuf, int rc ) {
+	struct ib_cmrc_connection *cmrc = ib_qp_get_ownerdata ( qp );
+
+	/* Free the completed I/O buffer */
+	free_iob ( iobuf );
+
+	/* Close the connection on any send errors */
+	if ( rc != 0 ) {
+		DBGC ( cmrc, "CMRC %p send error: %s\n",
+		       cmrc, strerror ( rc ) );
+		ib_cmrc_close ( cmrc, rc );
+		return;
+	}
+}
+
+/**
+ * Handle CMRC receive completion
+ *
+ * @v ibdev		Infiniband device
+ * @v qp		Queue pair
+ * @v av		Address vector, or NULL
+ * @v iobuf		I/O buffer
+ * @v rc		Completion status code
+ */
+static void ib_cmrc_complete_recv ( struct ib_device *ibdev __unused,
+				    struct ib_queue_pair *qp,
+				    struct ib_address_vector *av __unused,
+				    struct io_buffer *iobuf, int rc ) {
+	struct ib_cmrc_connection *cmrc = ib_qp_get_ownerdata ( qp );
+
+	/* Close the connection on any receive errors */
+	if ( rc != 0 ) {
+		DBGC ( cmrc, "CMRC %p receive error: %s\n",
+		       cmrc, strerror ( rc ) );
+		free_iob ( iobuf );
+		ib_cmrc_close ( cmrc, rc );
+		return;
+	}
+
+	DBGC2 ( cmrc, "CMRC %p received:\n", cmrc );
+	DBGC2_HDA ( cmrc, 0, iobuf->data, iob_len ( iobuf ) );
+
+	/* Pass up data */
+	if ( ( rc = xfer_deliver_iob ( &cmrc->xfer, iobuf ) ) != 0 ) {
+		DBGC ( cmrc, "CMRC %p could not deliver data: %s\n",
+		       cmrc, strerror ( rc ) );
+		ib_cmrc_close ( cmrc, rc );
+		return;
+	}
+}
+
+/** Infiniband CMRC completion operations */
+static struct ib_completion_queue_operations ib_cmrc_completion_ops = {
+	.complete_send = ib_cmrc_complete_send,
+	.complete_recv = ib_cmrc_complete_recv,
+};
+
+/**
+ * Send data via CMRC
+ *
+ * @v xfer		Data transfer interface
+ * @v iobuf		Datagram I/O buffer
+ * @v meta		Data transfer metadata
+ * @ret rc		Return status code
+ */
+static int ib_cmrc_xfer_deliver_iob ( struct xfer_interface *xfer,
+				      struct io_buffer *iobuf,
+				      struct xfer_metadata *meta __unused ) {
+	struct ib_cmrc_connection *cmrc =
+		container_of ( xfer, struct ib_cmrc_connection, xfer );
+	int rc;
+
+	/* If no connection has yet been attempted, send this datagram
+	 * as the CM REQ private data.  Otherwise, send it via the QP.
+	 */
+	if ( ! cmrc->connected ) {
+
+		/* Abort if we have already sent a CM connection request */
+		if ( cmrc->conn ) {
+			DBGC ( cmrc, "CMRC %p attempt to send before "
+			       "connection is complete\n", cmrc );
+			rc = -EIO;
+			goto out;
+		}
+
+		/* Send via CM connection request */
+		cmrc->conn = ib_create_conn ( cmrc->ibdev, cmrc->qp,
+					      &cmrc->dgid, &cmrc->service_id,
+					      iobuf->data, iob_len ( iobuf ),
+					      &ib_cmrc_conn_op );
+		if ( ! cmrc->conn ) {
+			DBGC ( cmrc, "CMRC %p could not connect\n", cmrc );
+			rc = -ENOMEM;
+			goto out;
+		}
+
+	} else {
+
+		/* Send via QP */
+		if ( ( rc = ib_post_send ( cmrc->ibdev, cmrc->qp, NULL,
+					   iob_disown ( iobuf ) ) ) != 0 ) {
+			DBGC ( cmrc, "CMRC %p could not send: %s\n",
+			       cmrc, strerror ( rc ) );
+			goto out;
+		}
+
+	}
+	return 0;
+
+ out:
+	/* Free the I/O buffer if necessary */
+	free_iob ( iobuf );
+
+	/* Close the connection on any errors */
+	if ( rc != 0 )
+		ib_cmrc_close ( cmrc, rc );
+
+	return rc;
+}
+
+/**
+ * Check CMRC flow control window
+ *
+ * @v xfer		Data transfer interface
+ * @ret len		Length of window
+ */
+static size_t ib_cmrc_xfer_window ( struct xfer_interface *xfer ) {
+	struct ib_cmrc_connection *cmrc =
+		container_of ( xfer, struct ib_cmrc_connection, xfer );
+
+	/* We indicate a window only when we are successfully
+	 * connected.
+	 */
+	return ( cmrc->connected ? IB_MAX_PAYLOAD_SIZE : 0 );
+}
+
+/**
+ * Close CMRC data-transfer interface
+ *
+ * @v xfer		Data transfer interface
+ * @v rc		Reason for close
+ */
+static void ib_cmrc_xfer_close ( struct xfer_interface *xfer, int rc ) {
+	struct ib_cmrc_connection *cmrc =
+		container_of ( xfer, struct ib_cmrc_connection, xfer );
+
+	DBGC ( cmrc, "CMRC %p closed: %s\n", cmrc, strerror ( rc ) );
+	ib_cmrc_close ( cmrc, rc );
+}
+
+/** CMRC data transfer interface operations */
+static struct xfer_interface_operations ib_cmrc_xfer_operations = {
+	.close		= ib_cmrc_xfer_close,
+	.vredirect	= ignore_xfer_vredirect,
+	.window		= ib_cmrc_xfer_window,
+	.alloc_iob	= default_xfer_alloc_iob,
+	.deliver_iob	= ib_cmrc_xfer_deliver_iob,
+	.deliver_raw	= xfer_deliver_as_iob,
+};
+
+/**
+ * Open CMRC connection
+ *
+ * @v xfer		Data transfer interface
+ * @v ibdev		Infiniband device
+ * @v dgid		Destination GID
+ * @v service_id	Service ID
+ * @ret rc		Returns status code
+ */
+int ib_cmrc_open ( struct xfer_interface *xfer, struct ib_device *ibdev,
+		   struct ib_gid *dgid, struct ib_gid_half *service_id ) {
+	struct ib_cmrc_connection *cmrc;
+	int rc;
+
+	/* Allocate and initialise structure */
+	cmrc = zalloc ( sizeof ( *cmrc ) );
+	if ( ! cmrc ) {
+		rc = -ENOMEM;
+		goto err_alloc;
+	}
+	xfer_init ( &cmrc->xfer, &ib_cmrc_xfer_operations, &cmrc->refcnt );
+	cmrc->ibdev = ibdev;
+	memcpy ( &cmrc->dgid, dgid, sizeof ( cmrc->dgid ) );
+	memcpy ( &cmrc->service_id, service_id, sizeof ( cmrc->service_id ) );
+	process_init_stopped ( &cmrc->shutdown, ib_cmrc_shutdown,
+			       &cmrc->refcnt );
+
+	/* Open Infiniband device */
+	if ( ( rc = ib_open ( ibdev ) ) != 0 ) {
+		DBGC ( cmrc, "CMRC %p could not open device: %s\n",
+		       cmrc, strerror ( rc ) );
+		goto err_open;
+	}
+
+	/* Create completion queue */
+	cmrc->cq = ib_create_cq ( ibdev, IB_CMRC_NUM_CQES,
+				  &ib_cmrc_completion_ops );
+	if ( ! cmrc->cq ) {
+		DBGC ( cmrc, "CMRC %p could not create completion queue\n",
+		       cmrc );
+		rc = -ENOMEM;
+		goto err_create_cq;
+	}
+
+	/* Create queue pair */
+	cmrc->qp = ib_create_qp ( ibdev, IB_QPT_RC, IB_CMRC_NUM_SEND_WQES,
+				  cmrc->cq, IB_CMRC_NUM_RECV_WQES, cmrc->cq );
+	if ( ! cmrc->qp ) {
+		DBGC ( cmrc, "CMRC %p could not create queue pair\n", cmrc );
+		rc = -ENOMEM;
+		goto err_create_qp;
+	}
+	ib_qp_set_ownerdata ( cmrc->qp, cmrc );
+	DBGC ( cmrc, "CMRC %p using QPN %lx\n", cmrc, cmrc->qp->qpn );
+
+	/* Attach to parent interface, transfer reference (implicitly)
+	 * to our shutdown process, and return.
+	 */
+	xfer_plug_plug ( &cmrc->xfer, xfer );
+	return 0;
+
+	ib_destroy_qp ( ibdev, cmrc->qp );
+ err_create_qp:
+	ib_destroy_cq ( ibdev, cmrc->cq );
+ err_create_cq:
+	ib_close ( ibdev );
+ err_open:
+	ref_put ( &cmrc->refcnt );
+ err_alloc:
+	return rc;
+}