drivers/scsi/isci/pool.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 /**
  57  * This file contains the interface to the pool class. This class allows two
  58  *    different two different priority tasks to insert and remove items from
  59  *    the free pool. The user of the pool is expected to evaluate the pool
  60  *    condition empty before a get operation and pool condition full before a
  61  *    put operation. Methods Provided: - sci_pool_create() -
  62  *    sci_pool_initialize() - sci_pool_empty() - sci_pool_full() -
  63  *    sci_pool_get() - sci_pool_put()
  64  *
  65  *
  66  */
  67
  68 #ifndef _SCI_POOL_H_
  69 #define _SCI_POOL_H_
  70
  71 /**
  72  * SCI_POOL_INCREMENT() -
  73  *
  74  * Private operation for the pool
  75  */
  76 #define SCI_POOL_INCREMENT(pool, index) \
  77         (((index) + 1) == (pool).size ? 0 : (index) + 1)
  78
  79 /**
  80  * SCI_POOL_CREATE() -
  81  *
  82  * This creates a pool structure of pool_name. The members in the pool are of
  83  * type with number of elements equal to size.
  84  */
  85 #define SCI_POOL_CREATE(pool_name, type, pool_size) \
  86         struct \
  87         { \
  88                 u32 size; \
  89                 u32 get; \
  90                 u32 put; \
  91                 type array[(pool_size) + 1]; \
  92         } pool_name
  93
  94
  95 /**
  96  * sci_pool_empty() -
  97  *
  98  * This macro evaluates the pool and returns true if the pool is empty. If the
  99  * pool is empty the user should not perform any get operation on the pool.
 100  */
 101 #define sci_pool_empty(pool) \
 102         ((pool).get == (pool).put)
 103
 104 /**
 105  * sci_pool_full() -
 106  *
 107  * This macro evaluates the pool and returns true if the pool is full.  If the
 108  * pool is full the user should not perform any put operation.
 109  */
 110 #define sci_pool_full(pool) \
 111         (SCI_POOL_INCREMENT(pool, (pool).put) == (pool).get)
 112
 113 /**
 114  * sci_pool_size() -
 115  *
 116  * This macro returns the size of the pool created.  The internal size of the
 117  * pool is actually 1 larger then necessary in order to ensure get and put
 118  * pointers can be written simultaneously by different users.  As a result,
 119  * this macro subtracts 1 from the internal size
 120  */
 121 #define sci_pool_size(pool) \
 122         ((pool).size - 1)
 123
 124 /**
 125  * sci_pool_count() -
 126  *
 127  * This macro indicates the number of elements currently contained in the pool.
 128  */
 129 #define sci_pool_count(pool) \
 130         (\
 131                 sci_pool_empty((pool)) \
 132                 ? 0 \
 133                 : (\
 134                         sci_pool_full((pool)) \
 135                         ? sci_pool_size((pool)) \
 136                         : (\
 137                                 (pool).get > (pool).put \
 138                                 ? ((pool).size - (pool).get + (pool).put) \
 139                                 : ((pool).put - (pool).get) \
 140                                 ) \
 141                         ) \
 142         )
 143
 144 /**
 145  * sci_pool_initialize() -
 146  *
 147  * This macro initializes the pool to an empty condition.
 148  */
 149 #define sci_pool_initialize(pool) \
 150         { \
 151                 (pool).size = (sizeof((pool).array) / sizeof((pool).array[0])); \
 152                 (pool).get = 0; \
 153                 (pool).put = 0; \
 154         }
 155
 156 /**
 157  * sci_pool_get() -
 158  *
 159  * This macro will get the next free element from the pool. This should only be
 160  * called if the pool is not empty.
 161  */
 162 #define sci_pool_get(pool, my_value) \
 163         { \
 164                 (my_value) = (pool).array[(pool).get]; \
 165                 (pool).get = SCI_POOL_INCREMENT((pool), (pool).get); \
 166         }
 167
 168 /**
 169  * sci_pool_put() -
 170  *
 171  * This macro will put the value into the pool. This should only be called if
 172  * the pool is not full.
 173  */
 174 #define sci_pool_put(pool, value) \
 175         { \
 176                 (pool).array[(pool).put] = (value); \
 177                 (pool).put = SCI_POOL_INCREMENT((pool), (pool).put); \
 178         }
 179
 180 /**
 181  * sci_pool_erase() -
 182  *
 183  * This macro will search the pool and remove any elements in the pool matching
 184  * the supplied value. This method can only be utilized on pools
 185  */
 186 #define sci_pool_erase(pool, type, value) \
 187         { \
 188                 type tmp_value; \
 189                 u32 index; \
 190                 u32 element_count = sci_pool_count((pool)); \
 191  \
 192                 for (index = 0; index < element_count; index++) {       \
 193                         sci_pool_get((pool), tmp_value); \
 194                         if (tmp_value != (value)) \
 195                                 sci_pool_put((pool), tmp_value); \
 196                 } \
 197         }
 198
 199 #endif /* _SCI_POOL_H_ */