1 /** @file
2 Implementation of synchronization functions on EBC.
3
4 Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php.
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 **/
14
15 /**
16 Performs an atomic compare exchange operation on a 16-bit
17 unsigned integer.
18
19 Performs an atomic compare exchange operation on the 16-bit
20 unsigned integer specified by Value. If Value is equal to
21 CompareValue, then Value is set to ExchangeValue and
22 CompareValue is returned. If Value is not equal to
23 CompareValue, then Value is returned. The compare exchange
24 operation must be performed using MP safe mechanisms.
25
26 @param Value A pointer to the 16-bit value for the
27 compare exchange operation.
28 @param CompareValue 16-bit value used in compare operation.
29 @param ExchangeValue 16-bit value used in exchange operation.
30
31 @return The original *Value before exchange.
32
33 **/
34 UINT16
35 EFIAPI
InternalSyncCompareExchange16(IN volatile UINT16 * Value,IN UINT16 CompareValue,IN UINT16 ExchangeValue)36 InternalSyncCompareExchange16 (
37 IN volatile UINT16 *Value,
38 IN UINT16 CompareValue,
39 IN UINT16 ExchangeValue
40 )
41 {
42 return *Value != CompareValue ? *Value :
43 ((*Value = ExchangeValue), CompareValue);
44 }
45
46 /**
47 Performs an atomic compare exchange operation on a 32-bit
48 unsigned integer.
49
50 Performs an atomic compare exchange operation on the 32-bit
51 unsigned integer specified by Value. If Value is equal to
52 CompareValue, then Value is set to ExchangeValue and
53 CompareValue is returned. If Value is not equal to
54 CompareValue, then Value is returned. The compare exchange
55 operation must be performed using MP safe mechanisms.
56
57 @param Value A pointer to the 32-bit value for the
58 compare exchange operation.
59 @param CompareValue 32-bit value used in compare operation.
60 @param ExchangeValue 32-bit value used in exchange operation.
61
62 @return The original *Value before exchange.
63
64 **/
65 UINT32
66 EFIAPI
InternalSyncCompareExchange32(IN volatile UINT32 * Value,IN UINT32 CompareValue,IN UINT32 ExchangeValue)67 InternalSyncCompareExchange32 (
68 IN volatile UINT32 *Value,
69 IN UINT32 CompareValue,
70 IN UINT32 ExchangeValue
71 )
72 {
73 return *Value != CompareValue ? *Value :
74 ((*Value = ExchangeValue), CompareValue);
75 }
76
77 /**
78 Performs an atomic compare exchange operation on a 64-bit unsigned integer.
79
80 Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
81 by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and
82 CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.
83 The compare exchange operation must be performed using MP safe mechanisms.
84
85 @param Value A pointer to the 64-bit value for the compare exchange
86 operation.
87 @param CompareValue 64-bit value used in compare operation.
88 @param ExchangeValue 64-bit value used in exchange operation.
89
90 @return The original *Value before exchange.
91
92 **/
93 UINT64
94 EFIAPI
InternalSyncCompareExchange64(IN volatile UINT64 * Value,IN UINT64 CompareValue,IN UINT64 ExchangeValue)95 InternalSyncCompareExchange64 (
96 IN volatile UINT64 *Value,
97 IN UINT64 CompareValue,
98 IN UINT64 ExchangeValue
99 )
100 {
101 return *Value != CompareValue ? *Value :
102 ((*Value = ExchangeValue), CompareValue);
103 }
104
105 /**
106 Performs an atomic increment of an 32-bit unsigned integer.
107
108 Performs an atomic increment of the 32-bit unsigned integer specified by
109 Value and returns the incremented value. The increment operation must be
110 performed using MP safe mechanisms. The state of the return value is not
111 guaranteed to be MP safe.
112
113 @param Value A pointer to the 32-bit value to increment.
114
115 @return The incremented value.
116
117 **/
118 UINT32
119 EFIAPI
InternalSyncIncrement(IN volatile UINT32 * Value)120 InternalSyncIncrement (
121 IN volatile UINT32 *Value
122 )
123 {
124 return ++*Value;
125 }
126
127 /**
128 Performs an atomic decrement of an 32-bit unsigned integer.
129
130 Performs an atomic decrement of the 32-bit unsigned integer specified by
131 Value and returns the decrement value. The decrement operation must be
132 performed using MP safe mechanisms. The state of the return value is not
133 guaranteed to be MP safe.
134
135 @param Value A pointer to the 32-bit value to decrement.
136
137 @return The decrement value.
138
139 **/
140 UINT32
141 EFIAPI
InternalSyncDecrement(IN volatile UINT32 * Value)142 InternalSyncDecrement (
143 IN volatile UINT32 *Value
144 )
145 {
146 return --*Value;
147 }
148