[mirror_ubuntu-artful-kernel.git] / drivers / infiniband / core / smi.c

/*
 * Copyright (c) 2004, 2005 Mellanox Technologies Ltd.  All rights reserved.
 * Copyright (c) 2004, 2005 Infinicon Corporation.  All rights reserved.
 * Copyright (c) 2004, 2005 Intel Corporation.  All rights reserved.
 * Copyright (c) 2004, 2005 Topspin Corporation.  All rights reserved.
 * Copyright (c) 2004-2007 Voltaire Corporation.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     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.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

#include <rdma/ib_smi.h>
#include "smi.h"

static enum smi_action __smi_handle_dr_smp_send(u8 node_type, int port_num,
						u8 *hop_ptr, u8 hop_cnt,
						const u8 *initial_path,
						const u8 *return_path,
						u8 direction,
						bool dr_dlid_is_permissive,
						bool dr_slid_is_permissive)
{
	/* See section 14.2.2.2, Vol 1 IB spec */
	/* C14-6 -- valid hop_cnt values are from 0 to 63 */
	if (hop_cnt >= IB_SMP_MAX_PATH_HOPS)
		return IB_SMI_DISCARD;

	if (!direction) {
		/* C14-9:1 */
		if (hop_cnt && *hop_ptr == 0) {
			(*hop_ptr)++;
			return (initial_path[*hop_ptr] ==
				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-9:2 */
		if (*hop_ptr && *hop_ptr < hop_cnt) {
			if (node_type != RDMA_NODE_IB_SWITCH)
				return IB_SMI_DISCARD;

			/* return_path set when received */
			(*hop_ptr)++;
			return (initial_path[*hop_ptr] ==
				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-9:3 -- We're at the end of the DR segment of path */
		if (*hop_ptr == hop_cnt) {
			/* return_path set when received */
			(*hop_ptr)++;
			return (node_type == RDMA_NODE_IB_SWITCH ||
				dr_dlid_is_permissive ?
				IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
		/* C14-9:5 -- Fail unreasonable hop pointer */
		return (*hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);

	} else {
		/* C14-13:1 */
		if (hop_cnt && *hop_ptr == hop_cnt + 1) {
			(*hop_ptr)--;
			return (return_path[*hop_ptr] ==
				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-13:2 */
		if (2 <= *hop_ptr && *hop_ptr <= hop_cnt) {
			if (node_type != RDMA_NODE_IB_SWITCH)
				return IB_SMI_DISCARD;

			(*hop_ptr)--;
			return (return_path[*hop_ptr] ==
				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-13:3 -- at the end of the DR segment of path */
		if (*hop_ptr == 1) {
			(*hop_ptr)--;
			/* C14-13:3 -- SMPs destined for SM shouldn't be here */
			return (node_type == RDMA_NODE_IB_SWITCH ||
				dr_slid_is_permissive ?
				IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-13:4 -- hop_ptr = 0 -> should have gone to SM */
		if (*hop_ptr == 0)
			return IB_SMI_HANDLE;

		/* C14-13:5 -- Check for unreasonable hop pointer */
		return IB_SMI_DISCARD;
	}
}

/*
 * Fixup a directed route SMP for sending
 * Return IB_SMI_DISCARD if the SMP should be discarded
 */
enum smi_action smi_handle_dr_smp_send(struct ib_smp *smp,
				       u8 node_type, int port_num)
{
	return __smi_handle_dr_smp_send(node_type, port_num,
					&smp->hop_ptr, smp->hop_cnt,
					smp->initial_path,
					smp->return_path,
					ib_get_smp_direction(smp),
					smp->dr_dlid == IB_LID_PERMISSIVE,
					smp->dr_slid == IB_LID_PERMISSIVE);
}

/*
 * Adjust information for a received SMP
 * Return IB_SMI_DISCARD if the SMP should be dropped
 */
enum smi_action smi_handle_dr_smp_recv(struct ib_smp *smp, u8 node_type,
				       int port_num, int phys_port_cnt)
{
	u8 hop_ptr, hop_cnt;

	hop_ptr = smp->hop_ptr;
	hop_cnt = smp->hop_cnt;

	/* See section 14.2.2.2, Vol 1 IB spec */
	/* C14-6 -- valid hop_cnt values are from 0 to 63 */
	if (hop_cnt >= IB_SMP_MAX_PATH_HOPS)
		return IB_SMI_DISCARD;

	if (!ib_get_smp_direction(smp)) {
		/* C14-9:1 -- sender should have incremented hop_ptr */
		if (hop_cnt && hop_ptr == 0)
			return IB_SMI_DISCARD;

		/* C14-9:2 -- intermediate hop */
		if (hop_ptr && hop_ptr < hop_cnt) {
			if (node_type != RDMA_NODE_IB_SWITCH)
				return IB_SMI_DISCARD;

			smp->return_path[hop_ptr] = port_num;
			/* smp->hop_ptr updated when sending */
			return (smp->initial_path[hop_ptr+1] <= phys_port_cnt ?
				IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-9:3 -- We're at the end of the DR segment of path */
		if (hop_ptr == hop_cnt) {
			if (hop_cnt)
				smp->return_path[hop_ptr] = port_num;
			/* smp->hop_ptr updated when sending */

			return (node_type == RDMA_NODE_IB_SWITCH ||
				smp->dr_dlid == IB_LID_PERMISSIVE ?
				IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
		/* C14-9:5 -- fail unreasonable hop pointer */
		return (hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);

	} else {

		/* C14-13:1 */
		if (hop_cnt && hop_ptr == hop_cnt + 1) {
			smp->hop_ptr--;
			return (smp->return_path[smp->hop_ptr] ==
				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-13:2 */
		if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
			if (node_type != RDMA_NODE_IB_SWITCH)
				return IB_SMI_DISCARD;

			/* smp->hop_ptr updated when sending */
			return (smp->return_path[hop_ptr-1] <= phys_port_cnt ?
				IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-13:3 -- We're at the end of the DR segment of path */
		if (hop_ptr == 1) {
			if (smp->dr_slid == IB_LID_PERMISSIVE) {
				/* giving SMP to SM - update hop_ptr */
				smp->hop_ptr--;
				return IB_SMI_HANDLE;
			}
			/* smp->hop_ptr updated when sending */
			return (node_type == RDMA_NODE_IB_SWITCH ?
				IB_SMI_HANDLE : IB_SMI_DISCARD);
		}

		/* C14-13:4 -- hop_ptr = 0 -> give to SM */
		/* C14-13:5 -- Check for unreasonable hop pointer */
		return (hop_ptr == 0 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
	}
}

enum smi_forward_action smi_check_forward_dr_smp(struct ib_smp *smp)
{
	u8 hop_ptr, hop_cnt;

	hop_ptr = smp->hop_ptr;
	hop_cnt = smp->hop_cnt;

	if (!ib_get_smp_direction(smp)) {
		/* C14-9:2 -- intermediate hop */
		if (hop_ptr && hop_ptr < hop_cnt)
			return IB_SMI_FORWARD;

		/* C14-9:3 -- at the end of the DR segment of path */
		if (hop_ptr == hop_cnt)
			return (smp->dr_dlid == IB_LID_PERMISSIVE ?
				IB_SMI_SEND : IB_SMI_LOCAL);

		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
		if (hop_ptr == hop_cnt + 1)
			return IB_SMI_SEND;
	} else {
		/* C14-13:2  -- intermediate hop */
		if (2 <= hop_ptr && hop_ptr <= hop_cnt)
			return IB_SMI_FORWARD;

		/* C14-13:3 -- at the end of the DR segment of path */
		if (hop_ptr == 1)
			return (smp->dr_slid != IB_LID_PERMISSIVE ?
				IB_SMI_SEND : IB_SMI_LOCAL);
	}
	return IB_SMI_LOCAL;
}

/*
 * Return the forwarding port number from initial_path for outgoing SMP and
 * from return_path for returning SMP
 */
int smi_get_fwd_port(struct ib_smp *smp)
{
	return (!ib_get_smp_direction(smp) ? smp->initial_path[smp->hop_ptr+1] :
		smp->return_path[smp->hop_ptr-1]);
}
Commit	Line	Data
1da177e4	1	/*
2a1d9b7f RD	2	* Copyright (c) 2004, 2005 Mellanox Technologies Ltd. All rights reserved.
	3	* Copyright (c) 2004, 2005 Infinicon Corporation. All rights reserved.
	4	* Copyright (c) 2004, 2005 Intel Corporation. All rights reserved.
	5	* Copyright (c) 2004, 2005 Topspin Corporation. All rights reserved.
de493d47	6	* Copyright (c) 2004-2007 Voltaire Corporation. All rights reserved.
2a1d9b7f	7	* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
1da177e4 LT	8	*
	9	* This software is available to you under a choice of one of two
	10	* licenses. You may choose to be licensed under the terms of the GNU
	11	* General Public License (GPL) Version 2, available from the file
	12	* COPYING in the main directory of this source tree, or the
	13	* OpenIB.org BSD license below:
	14	*
	15	* Redistribution and use in source and binary forms, with or
	16	* without modification, are permitted provided that the following
	17	* conditions are met:
	18	*
	19	* - Redistributions of source code must retain the above
	20	* copyright notice, this list of conditions and the following
	21	* disclaimer.
	22	*
	23	* - Redistributions in binary form must reproduce the above
	24	* copyright notice, this list of conditions and the following
	25	* disclaimer in the documentation and/or other materials
	26	* provided with the distribution.
	27	*
	28	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	29	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	30	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	31	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	32	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	33	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	34	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	35	* SOFTWARE.
	36	*
1da177e4 LT	37	*/
1da177e4 LT	38
a4d61e84	39	#include <rdma/ib_smi.h>
1da177e4 LT	40	#include "smi.h"
1da177e4 LT	41
92f15056 IW	42	static enum smi_action __smi_handle_dr_smp_send(u8 node_type, int port_num,
	43	u8 *hop_ptr, u8 hop_cnt,
	44	const u8 *initial_path,
	45	const u8 *return_path,
	46	u8 direction,
	47	bool dr_dlid_is_permissive,
	48	bool dr_slid_is_permissive)
1da177e4	49	{
1da177e4	50	/* See section 14.2.2.2, Vol 1 IB spec */
60f2b652 RD	51	/* C14-6 -- valid hop_cnt values are from 0 to 63 */
	52	if (hop_cnt >= IB_SMP_MAX_PATH_HOPS)
	53	return IB_SMI_DISCARD;
	54
92f15056	55	if (!direction) {
1da177e4	56	/* C14-9:1 */
92f15056 IW	57	if (hop_cnt && *hop_ptr == 0) {
	58	(*hop_ptr)++;
	59	return (initial_path[*hop_ptr] ==
de493d47	60	port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	61	}
	62
	63	/* C14-9:2 */
92f15056	64	if (hop_ptr && hop_ptr < hop_cnt) {
07ebafba	65	if (node_type != RDMA_NODE_IB_SWITCH)
de493d47	66	return IB_SMI_DISCARD;
1da177e4	67
92f15056 IW	68	/* return_path set when received */
	69	(*hop_ptr)++;
	70	return (initial_path[*hop_ptr] ==
de493d47	71	port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	72	}
	73
	74	/* C14-9:3 -- We're at the end of the DR segment of path */
92f15056 IW	75	if (*hop_ptr == hop_cnt) {
	76	/* return_path set when received */
	77	(*hop_ptr)++;
07ebafba	78	return (node_type == RDMA_NODE_IB_SWITCH \|\|
92f15056	79	dr_dlid_is_permissive ?
de493d47	80	IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	81	}
	82
	83	/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
	84	/* C14-9:5 -- Fail unreasonable hop pointer */
92f15056	85	return (*hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	86
	87	} else {
	88	/* C14-13:1 */
92f15056 IW	89	if (hop_cnt && *hop_ptr == hop_cnt + 1) {
	90	(*hop_ptr)--;
	91	return (return_path[*hop_ptr] ==
de493d47	92	port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	93	}
	94
	95	/* C14-13:2 */
92f15056	96	if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
07ebafba	97	if (node_type != RDMA_NODE_IB_SWITCH)
de493d47	98	return IB_SMI_DISCARD;
1da177e4	99
92f15056 IW	100	(*hop_ptr)--;
92f15056 IW	101	return (return_path[*hop_ptr] ==
de493d47	102	port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	103	}
	104
	105	/* C14-13:3 -- at the end of the DR segment of path */
92f15056 IW	106	if (*hop_ptr == 1) {
92f15056 IW	107	(*hop_ptr)--;
1da177e4	108	/* C14-13:3 -- SMPs destined for SM shouldn't be here */
07ebafba	109	return (node_type == RDMA_NODE_IB_SWITCH \|\|
92f15056	110	dr_slid_is_permissive ?
de493d47	111	IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	112	}
	113
	114	/* C14-13:4 -- hop_ptr = 0 -> should have gone to SM */
92f15056	115	if (*hop_ptr == 0)
de493d47	116	return IB_SMI_HANDLE;
1da177e4 LT	117
1da177e4 LT	118	/* C14-13:5 -- Check for unreasonable hop pointer */
de493d47	119	return IB_SMI_DISCARD;
1da177e4 LT	120	}
	121	}
	122
92f15056 IW	123	/*
	124	* Fixup a directed route SMP for sending
	125	* Return IB_SMI_DISCARD if the SMP should be discarded
	126	*/
	127	enum smi_action smi_handle_dr_smp_send(struct ib_smp *smp,
	128	u8 node_type, int port_num)
	129	{
	130	return __smi_handle_dr_smp_send(node_type, port_num,
	131	&smp->hop_ptr, smp->hop_cnt,
	132	smp->initial_path,
	133	smp->return_path,
	134	ib_get_smp_direction(smp),
	135	smp->dr_dlid == IB_LID_PERMISSIVE,
	136	smp->dr_slid == IB_LID_PERMISSIVE);
	137	}
	138
1da177e4 LT	139	/*
1da177e4 LT	140	* Adjust information for a received SMP
b78d28a2	141	* Return IB_SMI_DISCARD if the SMP should be dropped
1da177e4	142	*/
de493d47 HR	143	enum smi_action smi_handle_dr_smp_recv(struct ib_smp *smp, u8 node_type,
de493d47 HR	144	int port_num, int phys_port_cnt)
1da177e4 LT	145	{
	146	u8 hop_ptr, hop_cnt;
	147
	148	hop_ptr = smp->hop_ptr;
	149	hop_cnt = smp->hop_cnt;
	150
	151	/* See section 14.2.2.2, Vol 1 IB spec */
60f2b652 RD	152	/* C14-6 -- valid hop_cnt values are from 0 to 63 */
	153	if (hop_cnt >= IB_SMP_MAX_PATH_HOPS)
	154	return IB_SMI_DISCARD;
	155
1da177e4 LT	156	if (!ib_get_smp_direction(smp)) {
	157	/* C14-9:1 -- sender should have incremented hop_ptr */
	158	if (hop_cnt && hop_ptr == 0)
de493d47	159	return IB_SMI_DISCARD;
1da177e4 LT	160
	161	/* C14-9:2 -- intermediate hop */
	162	if (hop_ptr && hop_ptr < hop_cnt) {
07ebafba	163	if (node_type != RDMA_NODE_IB_SWITCH)
de493d47	164	return IB_SMI_DISCARD;
1da177e4 LT	165
	166	smp->return_path[hop_ptr] = port_num;
	167	/* smp->hop_ptr updated when sending */
de493d47 HR	168	return (smp->initial_path[hop_ptr+1] <= phys_port_cnt ?
de493d47 HR	169	IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	170	}
	171
	172	/* C14-9:3 -- We're at the end of the DR segment of path */
	173	if (hop_ptr == hop_cnt) {
	174	if (hop_cnt)
	175	smp->return_path[hop_ptr] = port_num;
	176	/* smp->hop_ptr updated when sending */
	177
07ebafba	178	return (node_type == RDMA_NODE_IB_SWITCH \|\|
de493d47 HR	179	smp->dr_dlid == IB_LID_PERMISSIVE ?
de493d47 HR	180	IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	181	}
	182
	183	/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
	184	/* C14-9:5 -- fail unreasonable hop pointer */
de493d47	185	return (hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	186
	187	} else {
	188
	189	/* C14-13:1 */
	190	if (hop_cnt && hop_ptr == hop_cnt + 1) {
	191	smp->hop_ptr--;
	192	return (smp->return_path[smp->hop_ptr] ==
de493d47	193	port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	194	}
	195
	196	/* C14-13:2 */
	197	if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
07ebafba	198	if (node_type != RDMA_NODE_IB_SWITCH)
de493d47	199	return IB_SMI_DISCARD;
1da177e4 LT	200
1da177e4 LT	201	/* smp->hop_ptr updated when sending */
de493d47 HR	202	return (smp->return_path[hop_ptr-1] <= phys_port_cnt ?
de493d47 HR	203	IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	204	}
	205
	206	/* C14-13:3 -- We're at the end of the DR segment of path */
	207	if (hop_ptr == 1) {
	208	if (smp->dr_slid == IB_LID_PERMISSIVE) {
	209	/* giving SMP to SM - update hop_ptr */
	210	smp->hop_ptr--;
de493d47	211	return IB_SMI_HANDLE;
1da177e4 LT	212	}
1da177e4 LT	213	/* smp->hop_ptr updated when sending */
de493d47	214	return (node_type == RDMA_NODE_IB_SWITCH ?
1bae4dbf	215	IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	216	}
	217
	218	/* C14-13:4 -- hop_ptr = 0 -> give to SM */
	219	/* C14-13:5 -- Check for unreasonable hop pointer */
de493d47	220	return (hop_ptr == 0 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
1da177e4 LT	221	}
	222	}
	223
de493d47	224	enum smi_forward_action smi_check_forward_dr_smp(struct ib_smp *smp)
1da177e4 LT	225	{
	226	u8 hop_ptr, hop_cnt;
	227
	228	hop_ptr = smp->hop_ptr;
	229	hop_cnt = smp->hop_cnt;
	230
	231	if (!ib_get_smp_direction(smp)) {
	232	/* C14-9:2 -- intermediate hop */
	233	if (hop_ptr && hop_ptr < hop_cnt)
1bae4dbf	234	return IB_SMI_FORWARD;
1da177e4 LT	235
	236	/* C14-9:3 -- at the end of the DR segment of path */
	237	if (hop_ptr == hop_cnt)
de493d47 HR	238	return (smp->dr_dlid == IB_LID_PERMISSIVE ?
de493d47 HR	239	IB_SMI_SEND : IB_SMI_LOCAL);
1da177e4 LT	240
	241	/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
	242	if (hop_ptr == hop_cnt + 1)
de493d47	243	return IB_SMI_SEND;
1da177e4	244	} else {
de493d47	245	/* C14-13:2 -- intermediate hop */
1da177e4	246	if (2 <= hop_ptr && hop_ptr <= hop_cnt)
1bae4dbf	247	return IB_SMI_FORWARD;
1da177e4 LT	248
	249	/* C14-13:3 -- at the end of the DR segment of path */
	250	if (hop_ptr == 1)
de493d47 HR	251	return (smp->dr_slid != IB_LID_PERMISSIVE ?
de493d47 HR	252	IB_SMI_SEND : IB_SMI_LOCAL);
1da177e4	253	}
de493d47	254	return IB_SMI_LOCAL;
1da177e4	255	}
1bae4dbf HR	256
	257	/*
	258	* Return the forwarding port number from initial_path for outgoing SMP and
	259	* from return_path for returning SMP
	260	*/
	261	int smi_get_fwd_port(struct ib_smp *smp)
	262	{
	263	return (!ib_get_smp_direction(smp) ? smp->initial_path[smp->hop_ptr+1] :
	264	smp->return_path[smp->hop_ptr-1]);
	265	}