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1 | /** @file\r |
2 | Timer Library functions built upon local APIC on IA32/x64.\r |
3 | \r |
4 | @bug Should use PCD to retrieve all the constants including index of\r |
5 | the IA32_APIC_BASE MSR, the offsets of InitialCount, CorrentCount\r |
6 | and DivideConfiguration.\r |
7 | \r |
8 | Copyright (c) 2006, Intel Corporation<BR>\r |
9 | All rights reserved. This program and the accompanying materials\r |
10 | are licensed and made available under the terms and conditions of the BSD License\r |
11 | which accompanies this distribution. The full text of the license may be found at\r |
12 | http://opensource.org/licenses/bsd-license.php\r |
13 | \r |
14 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r |
15 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r |
16 | \r |
17 | Module Name: x86TimerLib.c\r |
18 | \r |
19 | **/\r |
20 | \r |
21 | static\r |
22 | UINTN\r |
23 | EFIAPI\r |
24 | DelayWorker (\r |
25 | IN UINT64 NDelay\r |
26 | )\r |
27 | {\r |
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28 | UINT64 Ticks;\r |
29 | \r |
30 | Ticks = GetPerformanceCounter ();\r |
31 | Ticks -= DivU64x32 (\r |
32 | MultU64x64 (\r |
33 | GetPerformanceCounterProperties (NULL, NULL),\r |
34 | NDelay\r |
35 | ),\r |
36 | 1000000000u\r |
37 | );\r |
38 | while (Ticks <= GetPerformanceCounter ());\r |
39 | return (UINTN)Ticks;\r |
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40 | }\r |
41 | \r |
42 | /**\r |
43 | Stalls the CPU for at least the given number of microseconds.\r |
44 | \r |
45 | Stalls the CPU for the number of microseconds specified by MicroSeconds.\r |
46 | \r |
47 | @param MicroSeconds The minimum number of microseconds to delay.\r |
48 | \r |
49 | @return Return value depends on implementation.\r |
50 | \r |
51 | **/\r |
52 | UINTN\r |
53 | EFIAPI\r |
54 | MicroSecondDelay (\r |
55 | IN UINTN MicroSeconds\r |
56 | )\r |
57 | {\r |
58 | return DelayWorker (MicroSeconds * 1000ull);\r |
59 | }\r |
60 | \r |
61 | /**\r |
62 | Stalls the CPU for at least the given number of nanoseconds.\r |
63 | \r |
64 | Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r |
65 | \r |
66 | @param NanoSeconds The minimum number of nanoseconds to delay.\r |
67 | \r |
68 | @return Return value depends on implementation.\r |
69 | \r |
70 | **/\r |
71 | UINTN\r |
72 | EFIAPI\r |
73 | NanoSecondDelay (\r |
74 | IN UINTN NanoSeconds\r |
75 | )\r |
76 | {\r |
77 | return DelayWorker (NanoSeconds);\r |
78 | }\r |
79 | \r |
80 | static\r |
81 | UINTN\r |
82 | EFIAPI\r |
83 | GetApicBase (\r |
84 | VOID\r |
85 | )\r |
86 | {\r |
87 | return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;\r |
88 | }\r |
89 | \r |
90 | /**\r |
91 | Retrieves the current value of a 64-bit free running performance counter.\r |
92 | \r |
93 | Retrieves the current value of a 64-bit free running performance counter. The\r |
94 | counter can either count up by 1 or count down by 1. If the physical\r |
95 | performance counter counts by a larger increment, then the counter values\r |
96 | must be translated. The properties of the counter can be retrieved from\r |
97 | GetPerformanceCounterProperties().\r |
98 | \r |
99 | @return The current value of the free running performance counter.\r |
100 | \r |
101 | **/\r |
102 | UINT64\r |
103 | EFIAPI\r |
104 | GetPerformanceCounter (\r |
105 | VOID\r |
106 | )\r |
107 | {\r |
108 | return MmioRead32 (GetApicBase () + 0x390);\r |
109 | }\r |
110 | \r |
111 | /**\r |
112 | Retrieves the 64-bit frequency in Hz and the range of performance counter\r |
113 | values.\r |
114 | \r |
115 | If StartValue is not NULL, then the value that the performance counter starts\r |
116 | with immediately after is it rolls over is returned in StartValue. If\r |
117 | EndValue is not NULL, then the value that the performance counter end with\r |
118 | immediately before it rolls over is returned in EndValue. The 64-bit\r |
119 | frequency of the performance counter in Hz is always returned. If StartValue\r |
120 | is less than EndValue, then the performance counter counts up. If StartValue\r |
121 | is greater than EndValue, then the performance counter counts down. For\r |
122 | example, a 64-bit free running counter that counts up would have a StartValue\r |
123 | of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r |
124 | that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r |
125 | \r |
126 | @param StartValue The value the performance counter starts with when it\r |
127 | rolls over.\r |
128 | @param EndValue The value that the performance counter ends with before\r |
129 | it rolls over.\r |
130 | \r |
131 | @return The frequency in Hz.\r |
132 | \r |
133 | **/\r |
134 | UINT64\r |
135 | EFIAPI\r |
136 | GetPerformanceCounterProperties (\r |
137 | IN UINT64 *StartValue,\r |
138 | IN UINT64 *EndValue\r |
139 | )\r |
140 | {\r |
141 | static const UINT32 mFrequencies[] = {\r |
142 | 100000000,\r |
143 | 133000000,\r |
144 | 200000000,\r |
145 | 166000000\r |
146 | };\r |
147 | static const UINT8 mDivisor[] = {\r |
148 | 0x02, 0x04, 0x08, 0x10,\r |
149 | 0x02, 0x04, 0x08, 0x10,\r |
150 | 0x20, 0x40, 0x80, 0x01,\r |
151 | 0x20, 0x40, 0x80, 0x01\r |
152 | };\r |
153 | \r |
154 | UINTN ApicBase;\r |
155 | \r |
156 | ApicBase = GetApicBase ();\r |
157 | \r |
158 | if (StartValue != NULL) {\r |
159 | *StartValue = MmioRead32 (ApicBase + 0x380);\r |
160 | }\r |
161 | \r |
162 | if (EndValue != NULL) {\r |
163 | *EndValue = 0;\r |
164 | }\r |
165 | \r |
166 | return mFrequencies[AsmMsrBitFieldRead32 (44, 16, 18)] /\r |
167 | mDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];\r |
168 | }\r |