update GetPerformanceCounterProperties() declare
[mirror_edk2.git] / MdePkg / Library / BaseTimerLibLocalApic / Ebc / EbcTimerLib.c
CommitLineData
19b362e8 1/** @file\r
2 Timer Library functions for EBC.\r
3\r
4 Copyright (c) 2006, Intel Corporation<BR>\r
5 All rights reserved. This program and the accompanying materials\r
6 are licensed and made available under the terms and conditions of the BSD License\r
7 which accompanies this distribution. The full text of the license may be found at\r
8 http://opensource.org/licenses/bsd-license.php\r
9\r
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
12\r
13 Module Name: EbcTimerLib.c\r
14\r
15**/\r
16\r
17/**\r
18 Stalls the CPU for at least the given number of microseconds.\r
19\r
20 Stalls the CPU for the number of microseconds specified by MicroSeconds.\r
21\r
22 @param MicroSeconds The minimum number of microseconds to delay.\r
23\r
452e6c77 24 @return MicroSeconds\r
19b362e8 25\r
26**/\r
27UINTN\r
28EFIAPI\r
29MicroSecondDelay (\r
30 IN UINTN MicroSeconds\r
31 )\r
32{\r
33 //\r
34 // EBC architecture does not support local APIC timer.\r
35 //\r
36 ASSERT (FALSE);\r
452e6c77 37 return MicroSeconds;\r
19b362e8 38}\r
39\r
40/**\r
41 Stalls the CPU for at least the given number of nanoseconds.\r
42\r
43 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r
44\r
45 @param NanoSeconds The minimum number of nanoseconds to delay.\r
46\r
452e6c77 47 @return NanoSeconds\r
19b362e8 48\r
49**/\r
50UINTN\r
51EFIAPI\r
52NanoSecondDelay (\r
53 IN UINTN NanoSeconds\r
54 )\r
55{\r
56 //\r
57 // EBC architecture does not support local APIC timer.\r
58 //\r
59 ASSERT (FALSE);\r
452e6c77 60 return NanoSeconds;\r
19b362e8 61}\r
62\r
63/**\r
64 Retrieves the current value of a 64-bit free running performance counter.\r
65\r
66 Retrieves the current value of a 64-bit free running performance counter. The\r
67 counter can either count up by 1 or count down by 1. If the physical\r
68 performance counter counts by a larger increment, then the counter values\r
69 must be translated. The properties of the counter can be retrieved from\r
70 GetPerformanceCounterProperties().\r
71\r
72 @return The current value of the free running performance counter.\r
73\r
74**/\r
75UINT64\r
76EFIAPI\r
77GetPerformanceCounter (\r
78 VOID\r
79 )\r
80{\r
81 //\r
82 // EBC architecture does not support local APIC timer.\r
83 //\r
84 ASSERT (FALSE);\r
85 return 0;\r
86}\r
87\r
88/**\r
89 Retrieves the 64-bit frequency in Hz and the range of performance counter\r
90 values.\r
91\r
92 If StartValue is not NULL, then the value that the performance counter starts\r
93 with immediately after is it rolls over is returned in StartValue. If\r
94 EndValue is not NULL, then the value that the performance counter end with\r
95 immediately before it rolls over is returned in EndValue. The 64-bit\r
96 frequency of the performance counter in Hz is always returned. If StartValue\r
97 is less than EndValue, then the performance counter counts up. If StartValue\r
98 is greater than EndValue, then the performance counter counts down. For\r
99 example, a 64-bit free running counter that counts up would have a StartValue\r
100 of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r
101 that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r
102\r
103 @param StartValue The value the performance counter starts with when it\r
104 rolls over.\r
105 @param EndValue The value that the performance counter ends with before\r
106 it rolls over.\r
107\r
108 @return The frequency in Hz.\r
109\r
110**/\r
111UINT64\r
112EFIAPI\r
113GetPerformanceCounterProperties (\r
5117b83b 114 OUT UINT64 *StartValue, OPTIONAL\r
115 OUT UINT64 *EndValue OPTIONAL\r
19b362e8 116 )\r
117{\r
118 //\r
119 // EBC architecture does not support local APIC timer.\r
120 //\r
121 ASSERT (FALSE);\r
452e6c77 122 return 0;\r
19b362e8 123}\r