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  1. /*
  2.  * Copyright (c) 2006 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genarchmm
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Address space functions for global page hash table.
  36.  */
  37.  
  38. #include <arch/mm/as.h>
  39. #include <genarch/mm/as_ht.h>
  40. #include <genarch/mm/page_ht.h>
  41. #include <mm/as.h>
  42. #include <mm/frame.h>
  43. #include <arch/types.h>
  44. #include <memstr.h>
  45. #include <adt/hash_table.h>
  46. #include <synch/mutex.h>
  47.  
  48. static pte_t *ht_create(int flags);
  49. static void ht_destroy(pte_t *page_table);
  50.  
  51. static void ht_lock(as_t *as, bool lock);
  52. static void ht_unlock(as_t *as, bool unlock);
  53.  
  54. as_operations_t as_ht_operations = {
  55.     .page_table_create = ht_create,
  56.     .page_table_destroy = ht_destroy,
  57.     .page_table_lock = ht_lock,
  58.     .page_table_unlock = ht_unlock,
  59. };
  60.  
  61.  
  62. /** Page hash table create.
  63.  *
  64.  * The page hash table will be created only once
  65.  * and will be shared by all address spaces.
  66.  *
  67.  * @param flags Ignored.
  68.  *
  69.  * @return Returns NULL.
  70.  */
  71. pte_t *ht_create(int flags)
  72. {
  73.     if (flags & FLAG_AS_KERNEL) {
  74.         hash_table_create(&page_ht, PAGE_HT_ENTRIES, 2, &ht_operations);
  75.         mutex_initialize(&page_ht_lock, MUTEX_PASSIVE);
  76.     }
  77.     return NULL;
  78. }
  79.  
  80. /** Destroy page table.
  81.  *
  82.  * Actually do nothing as the global page hash table is used.
  83.  *
  84.  * @param page_table This parameter is ignored.
  85.  */
  86. void ht_destroy(pte_t *page_table)
  87. {
  88.     /* No-op. */
  89. }
  90.  
  91. /** Lock page table.
  92.  *
  93.  * Lock address space and page hash table.
  94.  * Interrupts must be disabled.
  95.  *
  96.  * @param as Address space.
  97.  * @param lock If false, do not attempt to lock the address space.
  98.  */
  99. void ht_lock(as_t *as, bool lock)
  100. {
  101.     if (lock)
  102.         mutex_lock(&as->lock);
  103.     mutex_lock(&page_ht_lock);
  104. }
  105.  
  106. /** Unlock page table.
  107.  *
  108.  * Unlock address space and page hash table.
  109.  * Interrupts must be disabled.
  110.  *
  111.  * @param as Address space.
  112.  * @param unlock If false, do not attempt to lock the address space.
  113.  */
  114. void ht_unlock(as_t *as, bool unlock)
  115. {
  116.     mutex_unlock(&page_ht_lock);
  117.     if (unlock)
  118.         mutex_unlock(&as->lock);
  119. }
  120.  
  121. /** @}
  122.  */
  123.