1 /** @file
2 GCC inline implementation of BaseSynchronizationLib processor specific functions.
3
4 Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
5 Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
6 This program and the accompanying materials
7 are licensed and made available under the terms and conditions of the BSD License
8 which accompanies this distribution. The full text of the license may be found at
9 http://opensource.org/licenses/bsd-license.php.
10
11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
13
14 **/
15
16
17
18 /**
19 Performs an atomic increment of an 32-bit unsigned integer.
20
21 Performs an atomic increment of the 32-bit unsigned integer specified by
22 Value and returns the incremented value. The increment operation must be
23 performed using MP safe mechanisms. The state of the return value is not
24 guaranteed to be MP safe.
25
26 @param Value A pointer to the 32-bit value to increment.
27
28 @return The incremented value.
29
30 **/
31 UINT32
32 EFIAPI
InternalSyncIncrement(IN volatile UINT32 * Value)33 InternalSyncIncrement (
34 IN volatile UINT32 *Value
35 )
36 {
37 UINT32 Result;
38
39 __asm__ __volatile__ (
40 "lock \n\t"
41 "incl %2 \n\t"
42 "movl %2, %%eax "
43 : "=a" (Result), // %0
44 "=m" (*Value) // %1
45 : "m" (*Value) // %2
46 : "memory",
47 "cc"
48 );
49
50 return Result;
51
52 }
53
54
55 /**
56 Performs an atomic decrement of an 32-bit unsigned integer.
57
58 Performs an atomic decrement of the 32-bit unsigned integer specified by
59 Value and returns the decremented value. The decrement operation must be
60 performed using MP safe mechanisms. The state of the return value is not
61 guaranteed to be MP safe.
62
63 @param Value A pointer to the 32-bit value to decrement.
64
65 @return The decremented value.
66
67 **/
68 UINT32
69 EFIAPI
InternalSyncDecrement(IN volatile UINT32 * Value)70 InternalSyncDecrement (
71 IN volatile UINT32 *Value
72 )
73 {
74 UINT32 Result;
75
76 __asm__ __volatile__ (
77 "lock \n\t"
78 "decl %2 \n\t"
79 "movl %2, %%eax "
80 : "=a" (Result), // %0
81 "=m" (*Value) // %1
82 : "m" (*Value) // %2
83 : "memory",
84 "cc"
85 );
86
87 return Result;
88 }
89
90 /**
91 Performs an atomic compare exchange operation on a 16-bit unsigned integer.
92
93 Performs an atomic compare exchange operation on the 16-bit unsigned integer
94 specified by Value. If Value is equal to CompareValue, then Value is set to
95 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
96 then Value is returned. The compare exchange operation must be performed using
97 MP safe mechanisms.
98
99
100 @param Value A pointer to the 16-bit value for the compare exchange
101 operation.
102 @param CompareValue 16-bit value used in compare operation.
103 @param ExchangeValue 16-bit value used in exchange operation.
104
105 @return The original *Value before exchange.
106
107 **/
108 UINT16
109 EFIAPI
InternalSyncCompareExchange16(IN OUT volatile UINT16 * Value,IN UINT16 CompareValue,IN UINT16 ExchangeValue)110 InternalSyncCompareExchange16 (
111 IN OUT volatile UINT16 *Value,
112 IN UINT16 CompareValue,
113 IN UINT16 ExchangeValue
114 )
115 {
116
117 __asm__ __volatile__ (
118 " \n\t"
119 "lock \n\t"
120 "cmpxchgw %1, %2 \n\t"
121 : "=a" (CompareValue)
122 : "q" (ExchangeValue),
123 "m" (*Value),
124 "0" (CompareValue)
125 : "memory",
126 "cc"
127 );
128
129 return CompareValue;
130 }
131
132 /**
133 Performs an atomic compare exchange operation on a 32-bit unsigned integer.
134
135 Performs an atomic compare exchange operation on the 32-bit unsigned integer
136 specified by Value. If Value is equal to CompareValue, then Value is set to
137 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
138 then Value is returned. The compare exchange operation must be performed using
139 MP safe mechanisms.
140
141
142 @param Value A pointer to the 32-bit value for the compare exchange
143 operation.
144 @param CompareValue 32-bit value used in compare operation.
145 @param ExchangeValue 32-bit value used in exchange operation.
146
147 @return The original *Value before exchange.
148
149 **/
150 UINT32
151 EFIAPI
InternalSyncCompareExchange32(IN OUT volatile UINT32 * Value,IN UINT32 CompareValue,IN UINT32 ExchangeValue)152 InternalSyncCompareExchange32 (
153 IN OUT volatile UINT32 *Value,
154 IN UINT32 CompareValue,
155 IN UINT32 ExchangeValue
156 )
157 {
158
159 __asm__ __volatile__ (
160 " \n\t"
161 "lock \n\t"
162 "cmpxchgl %1, %2 \n\t"
163 : "=a" (CompareValue) // %0
164 : "q" (ExchangeValue), // %1
165 "m" (*Value), // %2
166 "0" (CompareValue) // %4
167 : "memory",
168 "cc"
169 );
170
171 return CompareValue;
172 }
173
174 /**
175 Performs an atomic compare exchange operation on a 64-bit unsigned integer.
176
177 Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
178 by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and
179 CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.
180 The compare exchange operation must be performed using MP safe mechanisms.
181
182
183 @param Value A pointer to the 64-bit value for the compare exchange
184 operation.
185 @param CompareValue 64-bit value used in compare operation.
186 @param ExchangeValue 64-bit value used in exchange operation.
187
188 @return The original *Value before exchange.
189
190 **/
191 UINT64
192 EFIAPI
InternalSyncCompareExchange64(IN OUT volatile UINT64 * Value,IN UINT64 CompareValue,IN UINT64 ExchangeValue)193 InternalSyncCompareExchange64 (
194 IN OUT volatile UINT64 *Value,
195 IN UINT64 CompareValue,
196 IN UINT64 ExchangeValue
197 )
198 {
199 __asm__ __volatile__ (
200 " \n\t"
201 "push %%ebx \n\t"
202 "movl %2,%%ebx \n\t"
203 "lock \n\t"
204 "cmpxchg8b (%1) \n\t"
205 "pop %%ebx \n\t"
206 : "+A" (CompareValue) // %0
207 : "S" (Value), // %1
208 "r" ((UINT32) ExchangeValue), // %2
209 "c" ((UINT32) (ExchangeValue >> 32)) // %3
210 : "memory",
211 "cc"
212 );
213
214 return CompareValue;
215 }
216