drivers/scsi/isci/remote_node_table.h

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  * redistributing this file, you may do so under either license.
   4  *
   5  * GPL LICENSE SUMMARY
   6  *
   7  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called LICENSE.GPL.
  23  *
  24  * BSD LICENSE
  25  *
  26  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
  27  * All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  *
  33  *   * Redistributions of source code must retain the above copyright
  34  *     notice, this list of conditions and the following disclaimer.
  35  *   * Redistributions in binary form must reproduce the above copyright
  36  *     notice, this list of conditions and the following disclaimer in
  37  *     the documentation and/or other materials provided with the
  38  *     distribution.
  39  *   * Neither the name of Intel Corporation nor the names of its
  40  *     contributors may be used to endorse or promote products derived
  41  *     from this software without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  44  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  45  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  46  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  47  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  48  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  49  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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  52  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  53  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  54  */
  55
  56 #ifndef _SCIC_SDS_REMOTE_NODE_TABLE_H_
  57 #define _SCIC_SDS_REMOTE_NODE_TABLE_H_
  58
  59 #include "isci.h"
  60
  61 /**
  62  *
  63  *
  64  * Remote node sets are sets of remote node index in the remtoe node table The
  65  * SCU hardware requires that STP remote node entries take three consecutive
  66  * remote node index so the table is arranged in sets of three. The bits are
  67  * used as 0111 0111 to make a byte and the bits define the set of three remote
  68  * nodes to use as a sequence.
  69  */
  70 #define SCIC_SDS_REMOTE_NODE_SETS_PER_BYTE 2
  71
  72 /**
  73  *
  74  *
  75  * Since the remote node table is organized as DWORDS take the remote node sets
  76  * in bytes and represent them in DWORDs. The lowest ordered bits are the ones
  77  * used in case full DWORD is not being used. i.e. 0000 0000 0000 0000 0111
  78  * 0111 0111 0111 // if only a single WORD is in use in the DWORD.
  79  */
  80 #define SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD \
  81         (sizeof(u32) * SCIC_SDS_REMOTE_NODE_SETS_PER_BYTE)
  82 /**
  83  *
  84  *
  85  * This is a count of the numeber of remote nodes that can be represented in a
  86  * byte
  87  */
  88 #define SCIC_SDS_REMOTE_NODES_PER_BYTE  \
  89         (SCU_STP_REMOTE_NODE_COUNT * SCIC_SDS_REMOTE_NODE_SETS_PER_BYTE)
  90
  91 /**
  92  *
  93  *
  94  * This is a count of the number of remote nodes that can be represented in a
  95  * DWROD
  96  */
  97 #define SCIC_SDS_REMOTE_NODES_PER_DWORD \
  98         (sizeof(u32) * SCIC_SDS_REMOTE_NODES_PER_BYTE)
  99
 100 /**
 101  *
 102  *
 103  * This is the number of bits in a remote node group
 104  */
 105 #define SCIC_SDS_REMOTE_NODES_BITS_PER_GROUP   4
 106
 107 #define SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX      (0xFFFFFFFF)
 108 #define SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE    (0x07)
 109 #define SCIC_SDS_REMOTE_NODE_TABLE_EMPTY_SLOT_VALUE   (0x00)
 110
 111 /**
 112  *
 113  *
 114  * Expander attached sata remote node count
 115  */
 116 #define SCU_STP_REMOTE_NODE_COUNT        3
 117
 118 /**
 119  *
 120  *
 121  * Expander or direct attached ssp remote node count
 122  */
 123 #define SCU_SSP_REMOTE_NODE_COUNT        1
 124
 125 /**
 126  *
 127  *
 128  * Direct attached STP remote node count
 129  */
 130 #define SCU_SATA_REMOTE_NODE_COUNT       1
 131
 132 /**
 133  * struct sci_remote_node_table -
 134  *
 135  *
 136  */
 137 struct sci_remote_node_table {
 138         /**
 139          * This field contains the array size in dwords
 140          */
 141         u16 available_nodes_array_size;
 142
 143         /**
 144          * This field contains the array size of the
 145          */
 146         u16 group_array_size;
 147
 148         /**
 149          * This field is the array of available remote node entries in bits.
 150          * Because of the way STP remote node data is allocated on the SCU hardware
 151          * the remote nodes must occupy three consecutive remote node context
 152          * entries.  For ease of allocation and de-allocation we have broken the
 153          * sets of three into a single nibble.  When the STP RNi is allocated all
 154          * of the bits in the nibble are cleared.  This math results in a table size
 155          * of MAX_REMOTE_NODES / CONSECUTIVE RNi ENTRIES for STP / 2 entries per byte.
 156          */
 157         u32 available_remote_nodes[
 158                 (SCI_MAX_REMOTE_DEVICES / SCIC_SDS_REMOTE_NODES_PER_DWORD)
 159                 + ((SCI_MAX_REMOTE_DEVICES % SCIC_SDS_REMOTE_NODES_PER_DWORD) != 0)];
 160
 161         /**
 162          * This field is the nibble selector for the above table.  There are three
 163          * possible selectors each for fast lookup when trying to find one, two or
 164          * three remote node entries.
 165          */
 166         u32 remote_node_groups[
 167                 SCU_STP_REMOTE_NODE_COUNT][
 168                 (SCI_MAX_REMOTE_DEVICES / (32 * SCU_STP_REMOTE_NODE_COUNT))
 169                 + ((SCI_MAX_REMOTE_DEVICES % (32 * SCU_STP_REMOTE_NODE_COUNT)) != 0)];
 170
 171 };
 172
 173 /* --------------------------------------------------------------------------- */
 174
 175 void sci_remote_node_table_initialize(
 176         struct sci_remote_node_table *remote_node_table,
 177         u32 remote_node_entries);
 178
 179 u16 sci_remote_node_table_allocate_remote_node(
 180         struct sci_remote_node_table *remote_node_table,
 181         u32 remote_node_count);
 182
 183 void sci_remote_node_table_release_remote_node_index(
 184         struct sci_remote_node_table *remote_node_table,
 185         u32 remote_node_count,
 186         u16 remote_node_index);
 187
 188 #endif /* _SCIC_SDS_REMOTE_NODE_TABLE_H_ */