summaryrefslogtreecommitdiffstats
path: root/cpukit/score/inline/rtems/score/priority.inl
blob: 1a776d3419fab7a73461ecc0aeccb98fcde91fb6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/** 
 *  @file  rtems/score/priority.inl
 *
 *  This file contains the static inline implementation of all inlined
 *  routines in the Priority Handler.
 */

/*
 *  COPYRIGHT (c) 1989-2004.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.com/license/LICENSE.
 *
 *  $Id$
 */

#ifndef _RTEMS_SCORE_PRIORITY_INL
#define _RTEMS_SCORE_PRIORITY_INL

/**
 *  @addtogroup ScorePriority 
 *  @{
 */

#include <rtems/score/bitfield.h>

/**
 *  This routine performs the initialization necessary for this handler.
 */

RTEMS_INLINE_ROUTINE void _Priority_Handler_initialization( void )
{
  size_t index;

  _Priority_Major_bit_map = 0;
  for ( index=0 ; index <16 ; index++ )
     _Priority_Bit_map[ index ] = 0;
}

/**
 *  This function returns TRUE if the_priority if valid for a
 *  user task, and FALSE otherwise.
 */

RTEMS_INLINE_ROUTINE boolean _Priority_Is_valid (
  Priority_Control the_priority
)
{
  /* 
   *  Since PRIORITY_MINIMUM is 0 and priorities are stored unsigned,
   *  then checking for less than 0 is unnecessary.
   */

  return ( the_priority <= PRIORITY_MAXIMUM );
}

/**
 *  This function returns the major portion of the_priority.
 */

RTEMS_INLINE_ROUTINE uint32_t   _Priority_Major (
  Priority_Control the_priority
)
{
  return ( the_priority / 16 );
}

/**
 *  This function returns the minor portion of the_priority.
 */

RTEMS_INLINE_ROUTINE uint32_t   _Priority_Minor (
  Priority_Control the_priority
)
{
  return ( the_priority % 16 );
}

#if ( CPU_USE_GENERIC_BITFIELD_CODE == TRUE )
 
/**
 *  This function returns the mask associated with the major or minor
 *  number passed to it.
 */
 
RTEMS_INLINE_ROUTINE uint32_t   _Priority_Mask (
  uint32_t   bit_number
)
{
  return (0x8000 >> bit_number);
}
 
 
/**
 *  This function translates the bit numbers returned by the bit scan
 *  of a priority bit field into something suitable for use as
 *  a major or minor component of a priority.
 */
 
RTEMS_INLINE_ROUTINE uint32_t   _Priority_Bits_index (
  uint32_t   bit_number
)
{
  return bit_number;
}

#endif

/**
 *  This routine uses the_priority_map to update the priority
 *  bit maps to indicate that a thread has been readied.
 */

RTEMS_INLINE_ROUTINE void _Priority_Add_to_bit_map (
  Priority_Information *the_priority_map
)
{
  *the_priority_map->minor |= the_priority_map->ready_minor;
  _Priority_Major_bit_map  |= the_priority_map->ready_major;
}

/**
 *  This routine uses the_priority_map to update the priority
 *  bit maps to indicate that a thread has been removed from the
 *  ready state.
 */

RTEMS_INLINE_ROUTINE void _Priority_Remove_from_bit_map (
  Priority_Information *the_priority_map
)
{
  *the_priority_map->minor &= the_priority_map->block_minor;
  if ( *the_priority_map->minor == 0 )
    _Priority_Major_bit_map &= the_priority_map->block_major;
}

/**
 *  This function returns the priority of the highest priority
 *  ready thread.
 */

RTEMS_INLINE_ROUTINE Priority_Control _Priority_Get_highest( void )
{
  Priority_Bit_map_control minor;
  Priority_Bit_map_control major;

  _Bitfield_Find_first_bit( _Priority_Major_bit_map, major );
  _Bitfield_Find_first_bit( _Priority_Bit_map[major], minor );

  return (_Priority_Bits_index( major ) << 4) +
          _Priority_Bits_index( minor );
}

/**
 *  This routine initializes the_priority_map so that it
 *  contains the information necessary to manage a thread
 *  at new_priority.
 */

RTEMS_INLINE_ROUTINE void _Priority_Initialize_information(
  Priority_Information *the_priority_map,
  Priority_Control      new_priority
)
{
  Priority_Bit_map_control major;
  Priority_Bit_map_control minor;
  Priority_Bit_map_control mask;

  major = _Priority_Major( new_priority );
  minor = _Priority_Minor( new_priority );

  the_priority_map->minor =
    &_Priority_Bit_map[ _Priority_Bits_index(major) ];

  mask = _Priority_Mask( major );
  the_priority_map->ready_major = mask;
  the_priority_map->block_major = ~mask;

  mask = _Priority_Mask( minor );
  the_priority_map->ready_minor = mask;
  the_priority_map->block_minor = ~mask;
}

/**
 *  This function returns TRUE if the priority GROUP is empty, and
 *  FALSE otherwise.
 */

RTEMS_INLINE_ROUTINE boolean _Priority_Is_group_empty (
  Priority_Control      the_priority
)
{
  return the_priority == 0;
}

/**@}*/

#endif
/* end of include file */