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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 |
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21 | //\r |
22 | // The following 2 arrays are used in calculating the frequency of local APIC\r |
23 | // timer. Refer to IA-32 developers' manual for more details.\r |
24 | //\r |
25 | \r |
26 | GLOBAL_REMOVE_IF_UNREFERENCED\r |
27 | CONST UINT32 mTimerLibLocalApicFrequencies[] = {\r |
28 | 100000000,\r |
29 | 133000000,\r |
30 | 200000000,\r |
31 | 166000000\r |
32 | };\r |
33 | \r |
34 | GLOBAL_REMOVE_IF_UNREFERENCED\r |
35 | CONST UINT8 mTimerLibLocalApicDivisor[] = {\r |
36 | 0x02, 0x04, 0x08, 0x10,\r |
37 | 0x02, 0x04, 0x08, 0x10,\r |
38 | 0x20, 0x40, 0x80, 0x01,\r |
39 | 0x20, 0x40, 0x80, 0x01\r |
40 | };\r |
41 | \r |
42 | /**\r |
43 | Internal function to retrieve the base address of local APIC.\r |
44 | \r |
45 | Internal function to retrieve the base address of local APIC.\r |
46 | \r |
47 | @return The base address of local APIC\r |
48 | \r |
49 | **/\r |
50 | STATIC\r |
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51 | UINTN\r |
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52 | InternalX86GetApicBase (\r |
53 | VOID\r |
54 | )\r |
55 | {\r |
56 | return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;\r |
57 | }\r |
58 | \r |
59 | /**\r |
60 | Internal function to return the frequency of the local APIC timer.\r |
61 | \r |
62 | Internal function to return the frequency of the local APIC timer.\r |
63 | \r |
64 | @param ApicBase The base address of memory mapped registers of local APIC.\r |
65 | \r |
66 | @return The frequency of the timer in Hz.\r |
67 | \r |
68 | **/\r |
69 | STATIC\r |
70 | UINT32\r |
71 | InternalX86GetTimerFrequency (\r |
72 | IN UINTN ApicBase\r |
73 | )\r |
74 | {\r |
75 | return\r |
76 | mTimerLibLocalApicFrequencies[AsmMsrBitFieldRead32 (44, 16, 18)] /\r |
77 | mTimerLibLocalApicDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];\r |
78 | }\r |
79 | \r |
80 | /**\r |
81 | Internal function to read the current tick counter of local APIC.\r |
82 | \r |
83 | Internal function to read the current tick counter of local APIC.\r |
84 | \r |
85 | @param ApicBase The base address of memory mapped registers of local APIC.\r |
86 | \r |
87 | @return The tick counter read.\r |
88 | \r |
89 | **/\r |
90 | STATIC\r |
91 | INT32\r |
92 | InternalX86GetTimerTick (\r |
93 | IN UINTN ApicBase\r |
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94 | )\r |
95 | {\r |
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96 | return MmioRead32 (ApicBase + 0x390);\r |
97 | }\r |
98 | \r |
99 | /**\r |
100 | Stalls the CPU for at least the given number of ticks.\r |
101 | \r |
102 | Stalls the CPU for at least the given number of ticks. It's invoked by\r |
103 | MicroSecondDelay() and NanoSecondDelay().\r |
104 | \r |
105 | @param ApicBase The base address of memory mapped registers of local APIC.\r |
106 | @param Delay A period of time to delay in ticks.\r |
107 | \r |
108 | **/\r |
109 | STATIC\r |
110 | VOID\r |
111 | InternalX86Delay (\r |
112 | IN UINTN ApicBase,\r |
113 | IN UINT32 Delay\r |
114 | )\r |
115 | {\r |
116 | INT32 Ticks;\r |
117 | \r |
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118 | //\r |
119 | // The target timer count is calculated here\r |
120 | //\r |
121 | Ticks = InternalX86GetTimerTick (ApicBase) - Delay;\r |
122 | \r |
123 | //\r |
124 | // Wait until time out\r |
125 | // Delay > 2^31 could not be handled by this function\r |
126 | // Timer wrap-arounds are handled correctly by this function\r |
127 | //\r |
128 | while (InternalX86GetTimerTick (ApicBase) - Ticks >= 0);\r |
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129 | }\r |
130 | \r |
131 | /**\r |
132 | Stalls the CPU for at least the given number of microseconds.\r |
133 | \r |
134 | Stalls the CPU for the number of microseconds specified by MicroSeconds.\r |
135 | \r |
136 | @param MicroSeconds The minimum number of microseconds to delay.\r |
137 | \r |
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138 | @return MicroSeconds\r |
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139 | \r |
140 | **/\r |
141 | UINTN\r |
142 | EFIAPI\r |
143 | MicroSecondDelay (\r |
144 | IN UINTN MicroSeconds\r |
145 | )\r |
146 | {\r |
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147 | UINTN ApicBase;\r |
148 | \r |
149 | ApicBase = InternalX86GetApicBase ();\r |
150 | InternalX86Delay (\r |
151 | ApicBase,\r |
152 | (UINT32)DivU64x32 (\r |
153 | MultU64x64 (\r |
154 | InternalX86GetTimerFrequency (ApicBase),\r |
155 | MicroSeconds\r |
156 | ),\r |
157 | 1000000u\r |
158 | )\r |
159 | );\r |
160 | return MicroSeconds;\r |
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161 | }\r |
162 | \r |
163 | /**\r |
164 | Stalls the CPU for at least the given number of nanoseconds.\r |
165 | \r |
166 | Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r |
167 | \r |
168 | @param NanoSeconds The minimum number of nanoseconds to delay.\r |
169 | \r |
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170 | @return NanoSeconds\r |
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171 | \r |
172 | **/\r |
173 | UINTN\r |
174 | EFIAPI\r |
175 | NanoSecondDelay (\r |
176 | IN UINTN NanoSeconds\r |
177 | )\r |
178 | {\r |
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179 | UINTN ApicBase;\r |
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180 | \r |
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181 | ApicBase = InternalX86GetApicBase ();\r |
182 | InternalX86Delay (\r |
183 | ApicBase,\r |
184 | (UINT32)DivU64x32 (\r |
185 | MultU64x64 (\r |
186 | InternalX86GetTimerFrequency (ApicBase),\r |
187 | NanoSeconds\r |
188 | ),\r |
189 | 1000000000u\r |
190 | )\r |
191 | );\r |
192 | return NanoSeconds;\r |
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193 | }\r |
194 | \r |
195 | /**\r |
196 | Retrieves the current value of a 64-bit free running performance counter.\r |
197 | \r |
198 | Retrieves the current value of a 64-bit free running performance counter. The\r |
199 | counter can either count up by 1 or count down by 1. If the physical\r |
200 | performance counter counts by a larger increment, then the counter values\r |
201 | must be translated. The properties of the counter can be retrieved from\r |
202 | GetPerformanceCounterProperties().\r |
203 | \r |
204 | @return The current value of the free running performance counter.\r |
205 | \r |
206 | **/\r |
207 | UINT64\r |
208 | EFIAPI\r |
209 | GetPerformanceCounter (\r |
210 | VOID\r |
211 | )\r |
212 | {\r |
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213 | return (UINT64)(UINT32)InternalX86GetTimerTick (InternalX86GetApicBase ());\r |
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214 | }\r |
215 | \r |
216 | /**\r |
217 | Retrieves the 64-bit frequency in Hz and the range of performance counter\r |
218 | values.\r |
219 | \r |
220 | If StartValue is not NULL, then the value that the performance counter starts\r |
221 | with immediately after is it rolls over is returned in StartValue. If\r |
222 | EndValue is not NULL, then the value that the performance counter end with\r |
223 | immediately before it rolls over is returned in EndValue. The 64-bit\r |
224 | frequency of the performance counter in Hz is always returned. If StartValue\r |
225 | is less than EndValue, then the performance counter counts up. If StartValue\r |
226 | is greater than EndValue, then the performance counter counts down. For\r |
227 | example, a 64-bit free running counter that counts up would have a StartValue\r |
228 | of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r |
229 | that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r |
230 | \r |
231 | @param StartValue The value the performance counter starts with when it\r |
232 | rolls over.\r |
233 | @param EndValue The value that the performance counter ends with before\r |
234 | it rolls over.\r |
235 | \r |
236 | @return The frequency in Hz.\r |
237 | \r |
238 | **/\r |
239 | UINT64\r |
240 | EFIAPI\r |
241 | GetPerformanceCounterProperties (\r |
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242 | OUT UINT64 *StartValue, OPTIONAL\r |
243 | OUT UINT64 *EndValue OPTIONAL\r |
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244 | )\r |
245 | {\r |
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246 | UINTN ApicBase;\r |
247 | \r |
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248 | ApicBase = InternalX86GetApicBase ();\r |
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249 | \r |
250 | if (StartValue != NULL) {\r |
251 | *StartValue = MmioRead32 (ApicBase + 0x380);\r |
252 | }\r |
253 | \r |
254 | if (EndValue != NULL) {\r |
255 | *EndValue = 0;\r |
256 | }\r |
257 | \r |
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258 | return (UINT64)InternalX86GetTimerFrequency (ApicBase);\r |
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259 | }\r |