/*
 * 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.
 * Copyright (c) 2014 Intel Corporation.  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"
#include "opa_smi.h"

static enum smi_action __smi_handle_dr_smp_send(bool is_switch, u32 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 (!is_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 (is_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 (!is_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 (is_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,
                                       bool is_switch, u32 port_num)
{
        return __smi_handle_dr_smp_send(is_switch, 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);
}

enum smi_action opa_smi_handle_dr_smp_send(struct opa_smp *smp,
                                       bool is_switch, u32 port_num)
{
        return __smi_handle_dr_smp_send(is_switch, port_num,
                                        &smp->hop_ptr, smp->hop_cnt,
                                        smp->route.dr.initial_path,
                                        smp->route.dr.return_path,
                                        opa_get_smp_direction(smp),
                                        smp->route.dr.dr_dlid ==
                                        OPA_LID_PERMISSIVE,
                                        smp->route.dr.dr_slid ==
                                        OPA_LID_PERMISSIVE);
}

static enum smi_action __smi_handle_dr_smp_recv(bool is_switch, u32 port_num,
                                                int phys_port_cnt,
                                                u8 *hop_ptr, u8 hop_cnt,
                                                const u8 *initial_path,
                                                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 -- 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 (!is_switch)
                                return IB_SMI_DISCARD;

                        return_path[*hop_ptr] = port_num;
                        /* hop_ptr updated when sending */
                        return (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)
                                return_path[*hop_ptr] = port_num;
                        /* hop_ptr updated when sending */

                        return (is_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 (!is_switch)
                                return IB_SMI_DISCARD;

                        /* hop_ptr updated when sending */
                        return (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 (dr_slid_is_permissive) {
                                /* giving SMP to SM - update hop_ptr */
                                (*hop_ptr)--;
                                return IB_SMI_HANDLE;
                        }
                        /* hop_ptr updated when sending */
                        return (is_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);
        }
}

/*
 * 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, bool is_switch,
                                       u32 port_num, int phys_port_cnt)
{
        return __smi_handle_dr_smp_recv(is_switch, port_num, phys_port_cnt,
                                        &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 opa_smi_handle_dr_smp_recv(struct opa_smp *smp, bool is_switch,
                                           u32 port_num, int phys_port_cnt)
{
        return __smi_handle_dr_smp_recv(is_switch, port_num, phys_port_cnt,
                                        &smp->hop_ptr, smp->hop_cnt,
                                        smp->route.dr.initial_path,
                                        smp->route.dr.return_path,
                                        opa_get_smp_direction(smp),
                                        smp->route.dr.dr_dlid ==
                                        OPA_LID_PERMISSIVE,
                                        smp->route.dr.dr_slid ==
                                        OPA_LID_PERMISSIVE);
}

static enum smi_forward_action __smi_check_forward_dr_smp(u8 hop_ptr, u8 hop_cnt,
                                                          u8 direction,
                                                          bool dr_dlid_is_permissive,
                                                          bool dr_slid_is_permissive)
{
        if (!direction) {
                /* 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 (dr_dlid_is_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 (!dr_slid_is_permissive ?
                                IB_SMI_SEND : IB_SMI_LOCAL);
        }
        return IB_SMI_LOCAL;

}

enum smi_forward_action smi_check_forward_dr_smp(struct ib_smp *smp)
{
        return __smi_check_forward_dr_smp(smp->hop_ptr, smp->hop_cnt,
                                          ib_get_smp_direction(smp),
                                          smp->dr_dlid == IB_LID_PERMISSIVE,
                                          smp->dr_slid == IB_LID_PERMISSIVE);
}

enum smi_forward_action opa_smi_check_forward_dr_smp(struct opa_smp *smp)
{
        return __smi_check_forward_dr_smp(smp->hop_ptr, smp->hop_cnt,
                                          opa_get_smp_direction(smp),
                                          smp->route.dr.dr_dlid ==
                                          OPA_LID_PERMISSIVE,
                                          smp->route.dr.dr_slid ==
                                          OPA_LID_PERMISSIVE);
}

/*
 * 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]);
}

/*
 * Return the forwarding port number from initial_path for outgoing SMP and
 * from return_path for returning SMP
 */
int opa_smi_get_fwd_port(struct opa_smp *smp)
{
        return !opa_get_smp_direction(smp) ? smp->route.dr.initial_path[smp->hop_ptr+1] :
                smp->route.dr.return_path[smp->hop_ptr-1];
}