text: /*
   * 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, 2005 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.
   *
   * $Id: smi.c 1389 2004-12-27 22:56:47Z roland $
   */
  
  #include <rdma/ib_smi.h>
  #include "smi.h"
  
  /*
   * Fixup a directed route SMP for sending
   * Return 0 if the SMP should be discarded
   */
  int smi_handle_dr_smp_send(struct ib_smp *smp,
  			   u8 node_type,
  			   int port_num)
  {
  	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 */
  	if (!ib_get_smp_direction(smp)) {
  		/* C14-9:1 */
  		if (hop_cnt && hop_ptr == 0) {
  			smp->hop_ptr++;
  			return (smp->initial_path[smp->hop_ptr] ==
  				port_num);
  		}
  
  		/* C14-9:2 */
  		if (hop_ptr && hop_ptr < hop_cnt) {
  			if (node_type != IB_NODE_SWITCH)
  				return 0;
  
  			/* smp->return_path set when received */
  			smp->hop_ptr++;
  			return (smp->initial_path[smp->hop_ptr] ==
  				port_num);
  		}
  
  		/* C14-9:3 -- We're at the end of the DR segment of path */
  		if (hop_ptr == hop_cnt) {
  			/* smp->return_path set when received */
  			smp->hop_ptr++;
  			return (node_type == IB_NODE_SWITCH ||
  				smp->dr_dlid == IB_LID_PERMISSIVE);
  		}
  
  		/* 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);
  
  	} else {
  		/* C14-13:1 */
  		if (hop_cnt && hop_ptr == hop_cnt + 1) {
  			smp->hop_ptr--;
  			return (smp->return_path[smp->hop_ptr] ==
  				port_num);
  		}
  
  		/* C14-13:2 */
  		if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
  			if (node_type != IB_NODE_SWITCH)
  				return 0;
  
  			smp->hop_ptr--;
  			return (smp->return_path[smp->hop_ptr] ==
  				port_num);
  		}
  
  		/* C14-13:3 -- at the end of the DR segment of path */
  		if (hop_ptr == 1) {
  			smp->hop_ptr--;
  			/* C14-13:3 -- SMPs destined for SM shouldn't be here */
  			return (node_type == IB_NODE_SWITCH ||
  				smp->dr_slid == IB_LID_PERMISSIVE);
  		}
  
  		/* C14-13:4 -- hop_ptr = 0 -> should have gone to SM */
  		if (hop_ptr == 0)
  			return 1;
  
  		/* C14-13:5 -- Check for unreasonable hop pointer */
  		return 0;
  	}
  }
  
  /*
   * Adjust information for a received SMP
   * Return 0 if the SMP should be dropped
   */
  int 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 */
  	if (!ib_get_smp_direction(smp)) {
  		/* C14-9:1 -- sender should have incremented hop_ptr */
  		if (hop_cnt && hop_ptr == 0)
  			return 0;
  
  		/* C14-9:2 -- intermediate hop */
  		if (hop_ptr && hop_ptr < hop_cnt) {
  			if (node_type != IB_NODE_SWITCH)
  				return 0;
  
  			smp->return_path[hop_ptr] = port_num;
  			/* smp->hop_ptr updated when sending */
  			return (smp->initial_path[hop_ptr+1] <= phys_port_cnt);
  		}
  
  		/* 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 == IB_NODE_SWITCH ||
  				smp->dr_dlid == IB_LID_PERMISSIVE);
  		}
  
  		/* 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);
  
  	} else {
  
  		/* C14-13:1 */
  		if (hop_cnt && hop_ptr == hop_cnt + 1) {
  			smp->hop_ptr--;
  			return (smp->return_path[smp->hop_ptr] ==
  				port_num);
  		}
  
  		/* C14-13:2 */
  		if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
  			if (node_type != IB_NODE_SWITCH)
  				return 0;
  
  			/* smp->hop_ptr updated when sending */
  			return (smp->return_path[hop_ptr-1] <= phys_port_cnt);
  		}
  
  		/* 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 1;
  			}
  			/* smp->hop_ptr updated when sending */
  			return (node_type == IB_NODE_SWITCH);
  		}
  
  		/* C14-13:4 -- hop_ptr = 0 -> give to SM */
  		/* C14-13:5 -- Check for unreasonable hop pointer */
  		return (hop_ptr == 0);
  	}
  }
  
  /*
   * Return 1 if the received DR SMP should be forwarded to the send queue
   * Return 0 if the SMP should be completed up the stack
   */
  int 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 1;
  
  		/* C14-9:3 -- at the end of the DR segment of path */
  		if (hop_ptr == hop_cnt)
  			return (smp->dr_dlid == IB_LID_PERMISSIVE);
  
  		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
  		if (hop_ptr == hop_cnt + 1)
  			return 1;
  	} else {
  		/* C14-13:2 */
  		if (2 <= hop_ptr && hop_ptr <= hop_cnt)
  			return 1;
  
  		/* C14-13:3 -- at the end of the DR segment of path */
  		if (hop_ptr == 1)
  			return (smp->dr_slid != IB_LID_PERMISSIVE);
  	}
  	return 0;
  }
  