/*-
 * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 * 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
 * OWNER 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.
 */

#include <sys/cdefs.h>
/**
 * @file
 *
 * @brief This file contains the implementation of the
 *        SCIC_SDS_REMOTE_NODE_TABLE public, protected, and private methods.
 */

#include <dev/isci/scil/scic_sds_remote_node_table.h>
#include <dev/isci/scil/scic_sds_remote_node_context.h>

/**
 * This routine will find the bit position in absolute bit terms of the next
 * available bit for selection.  The absolute bit is index * 32 + bit
 * position.  If there are available bits in the first U32 then it is just bit
 * position.
 *  @param[in] remote_node_table This is the remote node index table from
 *       which the selection will be made.
 * @param[in] group_table_index This is the index to the group table from
 *       which to search for an available selection.
 *
 * @return U32 This is the absolute bit position for an available group.
 */
static
U32 scic_sds_remote_node_table_get_group_index(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        group_table_index
)
{
   U32   dword_index;
   U32 * group_table;
   U32   bit_index;

   group_table = remote_node_table->remote_node_groups[group_table_index];

   for (dword_index = 0; dword_index < remote_node_table->group_array_size; dword_index++)
   {
      if (group_table[dword_index] != 0)
      {
         for (bit_index = 0; bit_index < 32; bit_index++)
         {
            if ((group_table[dword_index] & (1 << bit_index)) != 0)
            {
               return (dword_index * 32) + bit_index;
            }
         }
      }
   }

   return SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX;
}

/**
 * This method will clear the group index entry in the specified group index
 * table.
 *
 * @param[in out] remote_node_table This the remote node table in which to
 *       clear the selector.
 * @param[in] set_index This is the remote node selector in which the change
 *       will be made.
 * @param[in] group_index This is the bit index in the table to be modified.
 *
 * @return none
 */
static
void scic_sds_remote_node_table_clear_group_index(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        group_table_index,
   U32                        group_index
)
{
   U32   dword_index;
   U32   bit_index;
   U32 * group_table;

   ASSERT(group_table_index < SCU_STP_REMOTE_NODE_COUNT);
   ASSERT(group_index < (U32)(remote_node_table->group_array_size * 32));

   dword_index = group_index / 32;
   bit_index   = group_index % 32;
   group_table = remote_node_table->remote_node_groups[group_table_index];

   group_table[dword_index] = group_table[dword_index] & ~(1 << bit_index);
}

/**
 * This method will set the group index bit entry in the specified group index
 * table.
 *
 * @param[in out] remote_node_table This the remote node table in which to set
 *       the selector.
 * @param[in] group_table_index This is the remote node selector in which the
 *       change will be made.
 * @param[in] group_index This is the bit position in the table to be
 *       modified.
 *
 * @return none
 */
static
void scic_sds_remote_node_table_set_group_index(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        group_table_index,
   U32                        group_index
)
{
   U32   dword_index;
   U32   bit_index;
   U32 * group_table;

   ASSERT(group_table_index < SCU_STP_REMOTE_NODE_COUNT);
   ASSERT(group_index < (U32)(remote_node_table->group_array_size * 32));

   dword_index = group_index / 32;
   bit_index   = group_index % 32;
   group_table = remote_node_table->remote_node_groups[group_table_index];

   group_table[dword_index] = group_table[dword_index] | (1 << bit_index);
}

/**
 * This method will set the remote to available in the remote node allocation
 * table.
 *
 * @param[in out] remote_node_table This is the remote node table in which to
 *       modify the remote node availability.
 * @param[in] remote_node_index This is the remote node index that is being
 *       returned to the table.
 *
 * @return none
 */
static
void scic_sds_remote_node_table_set_node_index(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        remote_node_index
)
{
   U32 dword_location;
   U32 dword_remainder;
   U32 slot_normalized;
   U32 slot_position;

   ASSERT(
        (remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
      > (remote_node_index / SCU_STP_REMOTE_NODE_COUNT)
   );

   dword_location  = remote_node_index / SCIC_SDS_REMOTE_NODES_PER_DWORD;
   dword_remainder = remote_node_index % SCIC_SDS_REMOTE_NODES_PER_DWORD;
   slot_normalized = (dword_remainder / SCU_STP_REMOTE_NODE_COUNT) * sizeof(U32);
   slot_position   = remote_node_index % SCU_STP_REMOTE_NODE_COUNT;

   remote_node_table->available_remote_nodes[dword_location] |=
      1 << (slot_normalized + slot_position);
}

/**
 * This method clears the remote node index from the table of available remote
 * nodes.
 *
 * @param[in out] remote_node_table This is the remote node table from which
 *       to clear the available remote node bit.
 * @param[in] remote_node_index This is the remote node index which is to be
 *       cleared from the table.
 *
 * @return none
 */
static
void scic_sds_remote_node_table_clear_node_index(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        remote_node_index
)
{
   U32 dword_location;
   U32 dword_remainder;
   U32 slot_position;
   U32 slot_normalized;

   ASSERT(
        (remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
      > (remote_node_index / SCU_STP_REMOTE_NODE_COUNT)
   );

   dword_location  = remote_node_index / SCIC_SDS_REMOTE_NODES_PER_DWORD;
   dword_remainder = remote_node_index % SCIC_SDS_REMOTE_NODES_PER_DWORD;
   slot_normalized = (dword_remainder / SCU_STP_REMOTE_NODE_COUNT) * sizeof(U32);
   slot_position   = remote_node_index % SCU_STP_REMOTE_NODE_COUNT;

   remote_node_table->available_remote_nodes[dword_location] &=
      ~(1 << (slot_normalized + slot_position));
}

/**
 * This method clears the entire table slot at the specified slot index.
 *
 * @param[in out] remote_node_table The remote node table from which the slot
 *       will be cleared.
 * @param[in] group_index The index for the slot that is to be cleared.
 *
 * @return none
 */
static
void scic_sds_remote_node_table_clear_group(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        group_index
)
{
   U32 dword_location;
   U32 dword_remainder;
   U32 dword_value;

   ASSERT(
        (remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
      > (group_index / SCU_STP_REMOTE_NODE_COUNT)
   );

   dword_location  = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
   dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;

   dword_value = remote_node_table->available_remote_nodes[dword_location];
   dword_value &= ~(SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
   remote_node_table->available_remote_nodes[dword_location] = dword_value;
}

/**
 * This method sets an entire remote node group in the remote node table.
 *
 * @param[in] remote_node_table
 * @param[in] group_index
 */
static
void scic_sds_remote_node_table_set_group(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        group_index
)
{
   U32 dword_location;
   U32 dword_remainder;
   U32 dword_value;

   ASSERT(
        (remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
      > (group_index / SCU_STP_REMOTE_NODE_COUNT)
   );

   dword_location  = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
   dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;

   dword_value = remote_node_table->available_remote_nodes[dword_location];
   dword_value |= (SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
   remote_node_table->available_remote_nodes[dword_location] = dword_value;
}

/**
 * This method will return the group value for the specified group index.
 *
 * @param[in] remote_node_table This is the remote node table that for which
 *       the group value is to be returned.
 * @param[in] group_index This is the group index to use to find the group
 *       value.
 *
 * @return The bit values at the specified remote node group index.
 */
static
U8 scic_sds_remote_node_table_get_group_value(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        group_index
)
{
   U32 dword_location;
   U32 dword_remainder;
   U32 dword_value;

   dword_location  = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
   dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;

   dword_value = remote_node_table->available_remote_nodes[dword_location];
   dword_value &= (SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
   dword_value = dword_value >> (dword_remainder * 4);

   return (U8)dword_value;
}

/**
 * This method will initialize the remote node table for use.
 *
 * @param[in out] remote_node_table The remote that which is to be
 *       initialized.
 * @param[in] remote_node_entries The number of entries to put in the table.
 *
 * @return none
 */
void scic_sds_remote_node_table_initialize(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        remote_node_entries
)
{
   U32 index;

   // Initialize the raw data we could improve the speed by only initializing
   // those entries that we are actually going to be used
   memset(
      remote_node_table->available_remote_nodes,
      0x00,
      sizeof(remote_node_table->available_remote_nodes)
   );

   memset(
      remote_node_table->remote_node_groups,
      0x00,
      sizeof(remote_node_table->remote_node_groups)
   );

   // Initialize the available remote node sets
   remote_node_table->available_nodes_array_size = (U16)
        (remote_node_entries / SCIC_SDS_REMOTE_NODES_PER_DWORD)
      + ((remote_node_entries % SCIC_SDS_REMOTE_NODES_PER_DWORD) != 0);


   // Initialize each full DWORD to a FULL SET of remote nodes
   for (index = 0; index < remote_node_entries; index++)
   {
      scic_sds_remote_node_table_set_node_index(remote_node_table, index);
   }

   remote_node_table->group_array_size = (U16)
        (remote_node_entries / (SCU_STP_REMOTE_NODE_COUNT * 32))
      + ((remote_node_entries % (SCU_STP_REMOTE_NODE_COUNT * 32)) != 0);

   for (index = 0; index < (remote_node_entries / SCU_STP_REMOTE_NODE_COUNT); index++)
   {
      // These are all guaranteed to be full slot values so fill them in the
      // available sets of 3 remote nodes
      scic_sds_remote_node_table_set_group_index(remote_node_table, 2, index);
   }

   // Now fill in any remainders that we may find
   if ((remote_node_entries % SCU_STP_REMOTE_NODE_COUNT) == 2)
   {
      scic_sds_remote_node_table_set_group_index(remote_node_table, 1, index);
   }
   else if ((remote_node_entries % SCU_STP_REMOTE_NODE_COUNT) == 1)
   {
      scic_sds_remote_node_table_set_group_index(remote_node_table, 0, index);
   }
}

/**
 * This method will allocate a single RNi from the remote node table.  The
 * table index will determine from which remote node group table to search.
 * This search may fail and another group node table can be specified.  The
 * function is designed to allow a serach of the available single remote node
 * group up to the triple remote node group.  If an entry is found in the
 * specified table the remote node is removed and the remote node groups are
 * updated.
 *
 * @param[in out] remote_node_table The remote node table from which to
 *       allocate a remote node.
 * @param[in] table_index The group index that is to be used for the search.
 *
 * @return The RNi value or an invalid remote node context if an RNi can not
 *         be found.
 */
static
U16 scic_sds_remote_node_table_allocate_single_remote_node(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        group_table_index
)
{
   U8  index;
   U8  group_value;
   U32 group_index;
   U16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;

   group_index = scic_sds_remote_node_table_get_group_index(
                                             remote_node_table, group_table_index);

   // We could not find an available slot in the table selector 0
   if (group_index != SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX)
   {
      group_value = scic_sds_remote_node_table_get_group_value(
                                    remote_node_table, group_index);

      for (index = 0; index < SCU_STP_REMOTE_NODE_COUNT; index++)
      {
         if (((1 << index) & group_value) != 0)
         {
            // We have selected a bit now clear it
            remote_node_index = (U16) (group_index * SCU_STP_REMOTE_NODE_COUNT
                                       + index);

            scic_sds_remote_node_table_clear_group_index(
               remote_node_table, group_table_index, group_index
            );

            scic_sds_remote_node_table_clear_node_index(
               remote_node_table, remote_node_index
            );

            if (group_table_index > 0)
            {
               scic_sds_remote_node_table_set_group_index(
                  remote_node_table, group_table_index - 1, group_index
               );
            }

            break;
         }
      }
   }

   return remote_node_index;
}

/**
 * This method will allocate three consecutive remote node context entries. If
 * there are no remaining triple entries the function will return a failure.
 *
 * @param[in] remote_node_table This is the remote node table from which to
 *       allocate the remote node entries.
 * @param[in] group_table_index This is the group table index which must equal
 *       two (2) for this operation.
 *
 * @return The remote node index that represents three consecutive remote node
 *         entries or an invalid remote node context if none can be found.
 */
static
U16 scic_sds_remote_node_table_allocate_triple_remote_node(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        group_table_index
)
{
   U32 group_index;
   U16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;

   group_index = scic_sds_remote_node_table_get_group_index(
                                             remote_node_table, group_table_index);

   if (group_index != SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX)
   {
      remote_node_index = (U16) group_index * SCU_STP_REMOTE_NODE_COUNT;

      scic_sds_remote_node_table_clear_group_index(
         remote_node_table, group_table_index, group_index
      );

      scic_sds_remote_node_table_clear_group(
         remote_node_table, group_index
      );
   }

   return remote_node_index;
}

/**
 * This method will allocate a remote node that mataches the remote node count
 * specified by the caller.  Valid values for remote node count is
 * SCU_SSP_REMOTE_NODE_COUNT(1) or SCU_STP_REMOTE_NODE_COUNT(3).
 *
 * @param[in] remote_node_table This is the remote node table from which the
 *       remote node allocation is to take place.
 * @param[in] remote_node_count This is ther remote node count which is one of
 *       SCU_SSP_REMOTE_NODE_COUNT(1) or SCU_STP_REMOTE_NODE_COUNT(3).
 *
 * @return U16 This is the remote node index that is returned or an invalid
 *         remote node context.
 */
U16 scic_sds_remote_node_table_allocate_remote_node(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        remote_node_count
)
{
   U16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;

   if (remote_node_count == SCU_SSP_REMOTE_NODE_COUNT)
   {
      remote_node_index =
         scic_sds_remote_node_table_allocate_single_remote_node(
                                                         remote_node_table, 0);

      if (remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX)
      {
         remote_node_index =
            scic_sds_remote_node_table_allocate_single_remote_node(
                                                         remote_node_table, 1);
      }

      if (remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX)
      {
         remote_node_index =
            scic_sds_remote_node_table_allocate_single_remote_node(
                                                         remote_node_table, 2);
      }
   }
   else if (remote_node_count == SCU_STP_REMOTE_NODE_COUNT)
   {
      remote_node_index =
         scic_sds_remote_node_table_allocate_triple_remote_node(
                                                         remote_node_table, 2);
   }

   return remote_node_index;
}

/**
 * This method will free a single remote node index back to the remote node
 * table.  This routine will update the remote node groups
 *
 * @param[in] remote_node_table
 * @param[in] remote_node_index
 */
static
void scic_sds_remote_node_table_release_single_remote_node(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U16                        remote_node_index
)
{
   U32 group_index;
   U8  group_value;

   group_index = remote_node_index / SCU_STP_REMOTE_NODE_COUNT;

   group_value = scic_sds_remote_node_table_get_group_value(remote_node_table, group_index);

   // Assert that we are not trying to add an entry to a slot that is already
   // full.
   ASSERT(group_value != SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE);

   if (group_value == 0x00)
   {
      // There are no entries in this slot so it must be added to the single
      // slot table.
      scic_sds_remote_node_table_set_group_index(remote_node_table, 0, group_index);
   }
   else if ((group_value & (group_value -1)) == 0)
   {
      // There is only one entry in this slot so it must be moved from the
      // single slot table to the dual slot table
      scic_sds_remote_node_table_clear_group_index(remote_node_table, 0, group_index);
      scic_sds_remote_node_table_set_group_index(remote_node_table, 1, group_index);
   }
   else
   {
      // There are two entries in the slot so it must be moved from the dual
      // slot table to the tripple slot table.
      scic_sds_remote_node_table_clear_group_index(remote_node_table, 1, group_index);
      scic_sds_remote_node_table_set_group_index(remote_node_table, 2, group_index);
   }

   scic_sds_remote_node_table_set_node_index(remote_node_table, remote_node_index);
}

/**
 * This method will release a group of three consecutive remote nodes back to
 * the free remote nodes.
 *
 * @param[in] remote_node_table This is the remote node table to which the
 *       remote node index is to be freed.
 * @param[in] remote_node_index This is the remote node index which is being
 *       freed.
 */
static
void scic_sds_remote_node_table_release_triple_remote_node(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U16                        remote_node_index
)
{
   U32 group_index;

   group_index = remote_node_index / SCU_STP_REMOTE_NODE_COUNT;

   scic_sds_remote_node_table_set_group_index(
      remote_node_table, 2, group_index
   );

   scic_sds_remote_node_table_set_group(remote_node_table, group_index);
}

/**
 * This method will release the remote node index back into the remote node
 * table free pool.
 *
 * @param[in] remote_node_table The remote node table to which the remote node
 *       index is to be freed.
 * @param[in] remote_node_count This is the count of consecutive remote nodes
 *       that are to be freed.
 * @param[in] remote_node_index This is the remote node index of the start of
 *       the number of remote nodes to be freed.
 */
void scic_sds_remote_node_table_release_remote_node_index(
   SCIC_REMOTE_NODE_TABLE_T * remote_node_table,
   U32                        remote_node_count,
   U16                        remote_node_index
)
{
   if (remote_node_count == SCU_SSP_REMOTE_NODE_COUNT)
   {
      scic_sds_remote_node_table_release_single_remote_node(
                                       remote_node_table, remote_node_index);
   }
   else if (remote_node_count == SCU_STP_REMOTE_NODE_COUNT)
   {
      scic_sds_remote_node_table_release_triple_remote_node(
                                       remote_node_table, remote_node_index);
   }
}