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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   FIFO queue ASID management.
  36.  *
  37.  * Architectures that link with this file keep the unallocated ASIDs
  38.  * in FIFO queue. The queue can be statically (e.g. mips32) or
  39.  * dynamically allocated (e.g ia64 and sparc64).
  40.  */
  41.  
  42. #include <genarch/mm/asid_fifo.h>
  43. #include <arch/mm/asid.h>
  44. #include <mm/asid.h>
  45. #include <typedefs.h>
  46. #include <adt/fifo.h>
  47.  
  48. #define FIFO_STATIC_LIMIT   1024
  49. #define FIFO_STATIC     (ASIDS_ALLOCABLE<FIFO_STATIC_LIMIT)
  50.  
  51. /**
  52.  * FIFO queue containing unassigned ASIDs.
  53.  * Can be only accessed when asidlock is held.
  54.  */
  55. #if FIFO_STATIC
  56. FIFO_INITIALIZE_STATIC(free_asids, asid_t, ASIDS_ALLOCABLE);
  57. #else
  58. FIFO_INITIALIZE_DYNAMIC(free_asids, asid_t, ASIDS_ALLOCABLE);
  59. #endif
  60.  
  61. /** Initialize data structures for O(1) ASID allocation and deallocation. */
  62. void asid_fifo_init(void)
  63. {
  64.     int i;
  65.  
  66. #if (!FIFO_STATIC)
  67.     fifo_create(free_asids);
  68. #endif
  69.        
  70.     for (i = 0; i < ASIDS_ALLOCABLE; i++) {
  71.         fifo_push(free_asids, ASID_START + i);
  72.     }
  73. }
  74.  
  75. /** Allocate free ASID.
  76.  *
  77.  * Allocation runs in O(1).
  78.  *
  79.  * @return Free ASID.
  80.  */
  81. asid_t asid_find_free(void)
  82. {
  83.     return fifo_pop(free_asids);
  84. }
  85.  
  86. /** Return ASID among free ASIDs.
  87.  *
  88.  * This operation runs in O(1).
  89.  *
  90.  * @param asid ASID being freed.
  91.  */
  92. void asid_put_arch(asid_t asid)
  93. {
  94.     fifo_push(free_asids, asid);
  95. }
  96.  
  97. /** @}
  98.  */
  99.