FreeBSD/Linux Kernel Cross Reference
sys/dev/isci/scil/scic_sds_remote_node_table.c

     /*-
      * 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>
    __FBSDID("$FreeBSD$");
    
    /**
     * @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);
      }
   }
   

Cache object: f316f1095b58c3727aef0468a29ecb45