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2057d8c8 | 1 | /** @file\r |
2 | Timer Library functions built upon local APIC on IA32/x64.\r | |
3 | \r | |
4 | This library uses the local APIC library so that it supports x2APIC mode.\r | |
5 | \r | |
f17e2f8c | 6 | Copyright (c) 2010 - 2015, Intel Corporation. All rights reserved.<BR>\r |
2057d8c8 | 7 | This program and the accompanying materials\r |
8 | are licensed and made available under the terms and conditions of the BSD License\r | |
9 | which accompanies this distribution. The full text of the license may be found at\r | |
10 | http://opensource.org/licenses/bsd-license.php.\r | |
11 | \r | |
12 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
13 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
14 | \r | |
15 | **/\r | |
16 | \r | |
17 | #include <Base.h>\r | |
18 | #include <Library/TimerLib.h>\r | |
19 | #include <Library/BaseLib.h>\r | |
20 | #include <Library/PcdLib.h>\r | |
21 | #include <Library/DebugLib.h>\r | |
22 | #include <Library/LocalApicLib.h>\r | |
23 | \r | |
24 | /**\r | |
25 | Internal function to return the frequency of the local APIC timer.\r | |
26 | \r | |
27 | @return The frequency of the timer in Hz.\r | |
28 | \r | |
29 | **/\r | |
30 | UINT32\r | |
31 | EFIAPI\r | |
32 | InternalX86GetTimerFrequency (\r | |
33 | VOID\r | |
34 | )\r | |
35 | {\r | |
36 | UINTN Divisor;\r | |
37 | \r | |
38 | GetApicTimerState (&Divisor, NULL, NULL);\r | |
39 | return PcdGet32(PcdFSBClock) / (UINT32)Divisor;\r | |
40 | }\r | |
41 | \r | |
42 | /**\r | |
43 | Stalls the CPU for at least the given number of ticks.\r | |
44 | \r | |
45 | Stalls the CPU for at least the given number of ticks. It's invoked by\r | |
46 | MicroSecondDelay() and NanoSecondDelay().\r | |
47 | \r | |
f17e2f8c HW |
48 | This function will ASSERT if the APIC timer intial count returned from\r |
49 | GetApicTimerInitCount() is zero.\r | |
50 | \r | |
2057d8c8 | 51 | @param Delay A period of time to delay in ticks.\r |
52 | \r | |
53 | **/\r | |
54 | VOID\r | |
55 | EFIAPI\r | |
56 | InternalX86Delay (\r | |
57 | IN UINT32 Delay\r | |
58 | )\r | |
59 | {\r | |
60 | INT32 Ticks;\r | |
253fcc8b JF |
61 | UINT32 Times;\r |
62 | UINT32 InitCount;\r | |
63 | UINT32 StartTick;\r | |
2057d8c8 | 64 | \r |
65 | //\r | |
253fcc8b JF |
66 | // In case Delay is too larger, separate it into several small delay slot.\r |
67 | // Devided Delay by half value of Init Count is to avoid Delay close to\r | |
68 | // the Init Count, timeout maybe missing if the time consuming between 2\r | |
69 | // GetApicTimerCurrentCount() invoking is larger than the time gap between\r | |
70 | // Delay and the Init Count.\r | |
2057d8c8 | 71 | //\r |
253fcc8b | 72 | InitCount = GetApicTimerInitCount ();\r |
f17e2f8c | 73 | ASSERT (InitCount != 0);\r |
253fcc8b JF |
74 | Times = Delay / (InitCount / 2);\r |
75 | Delay = Delay % (InitCount / 2);\r | |
2057d8c8 | 76 | \r |
77 | //\r | |
253fcc8b | 78 | // Get Start Tick and do delay\r |
2057d8c8 | 79 | //\r |
253fcc8b JF |
80 | StartTick = GetApicTimerCurrentCount ();\r |
81 | do {\r | |
82 | //\r | |
83 | // Wait until time out by Delay value\r | |
84 | //\r | |
85 | do {\r | |
86 | CpuPause ();\r | |
87 | //\r | |
88 | // Get Ticks from Start to Current.\r | |
89 | //\r | |
90 | Ticks = StartTick - GetApicTimerCurrentCount ();\r | |
91 | //\r | |
92 | // Ticks < 0 means Timer wrap-arounds happens.\r | |
93 | //\r | |
94 | if (Ticks < 0) {\r | |
95 | Ticks += InitCount;\r | |
96 | }\r | |
97 | } while ((UINT32)Ticks < Delay);\r | |
98 | \r | |
99 | //\r | |
100 | // Update StartTick and Delay for next delay slot\r | |
101 | //\r | |
102 | StartTick -= (StartTick > Delay) ? Delay : (Delay - InitCount);\r | |
103 | Delay = InitCount / 2;\r | |
104 | } while (Times-- > 0);\r | |
2057d8c8 | 105 | }\r |
106 | \r | |
107 | /**\r | |
108 | Stalls the CPU for at least the given number of microseconds.\r | |
109 | \r | |
110 | Stalls the CPU for the number of microseconds specified by MicroSeconds.\r | |
111 | \r | |
112 | @param MicroSeconds The minimum number of microseconds to delay.\r | |
113 | \r | |
114 | @return The value of MicroSeconds inputted.\r | |
115 | \r | |
116 | **/\r | |
117 | UINTN\r | |
118 | EFIAPI\r | |
119 | MicroSecondDelay (\r | |
120 | IN UINTN MicroSeconds\r | |
121 | )\r | |
122 | {\r | |
123 | InternalX86Delay (\r | |
124 | (UINT32)DivU64x32 (\r | |
125 | MultU64x64 (\r | |
126 | InternalX86GetTimerFrequency (),\r | |
127 | MicroSeconds\r | |
128 | ),\r | |
129 | 1000000u\r | |
130 | )\r | |
131 | );\r | |
132 | return MicroSeconds;\r | |
133 | }\r | |
134 | \r | |
135 | /**\r | |
136 | Stalls the CPU for at least the given number of nanoseconds.\r | |
137 | \r | |
138 | Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r | |
139 | \r | |
140 | @param NanoSeconds The minimum number of nanoseconds to delay.\r | |
141 | \r | |
142 | @return The value of NanoSeconds inputted.\r | |
143 | \r | |
144 | **/\r | |
145 | UINTN\r | |
146 | EFIAPI\r | |
147 | NanoSecondDelay (\r | |
148 | IN UINTN NanoSeconds\r | |
149 | )\r | |
150 | {\r | |
151 | InternalX86Delay (\r | |
152 | (UINT32)DivU64x32 (\r | |
153 | MultU64x64 (\r | |
154 | InternalX86GetTimerFrequency (),\r | |
155 | NanoSeconds\r | |
156 | ),\r | |
157 | 1000000000u\r | |
158 | )\r | |
159 | );\r | |
160 | return NanoSeconds;\r | |
161 | }\r | |
162 | \r | |
163 | /**\r | |
164 | Retrieves the current value of a 64-bit free running performance counter.\r | |
165 | \r | |
166 | The counter can either count up by 1 or count down by 1. If the physical\r | |
167 | performance counter counts by a larger increment, then the counter values\r | |
168 | must be translated. The properties of the counter can be retrieved from\r | |
169 | GetPerformanceCounterProperties().\r | |
170 | \r | |
171 | @return The current value of the free running performance counter.\r | |
172 | \r | |
173 | **/\r | |
174 | UINT64\r | |
175 | EFIAPI\r | |
176 | GetPerformanceCounter (\r | |
177 | VOID\r | |
178 | )\r | |
179 | {\r | |
180 | return (UINT64)GetApicTimerCurrentCount ();\r | |
181 | }\r | |
182 | \r | |
183 | /**\r | |
184 | Retrieves the 64-bit frequency in Hz and the range of performance counter\r | |
185 | values.\r | |
186 | \r | |
187 | If StartValue is not NULL, then the value that the performance counter starts\r | |
188 | with immediately after is it rolls over is returned in StartValue. If\r | |
189 | EndValue is not NULL, then the value that the performance counter end with\r | |
190 | immediately before it rolls over is returned in EndValue. The 64-bit\r | |
191 | frequency of the performance counter in Hz is always returned. If StartValue\r | |
192 | is less than EndValue, then the performance counter counts up. If StartValue\r | |
193 | is greater than EndValue, then the performance counter counts down. For\r | |
194 | example, a 64-bit free running counter that counts up would have a StartValue\r | |
195 | of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r | |
196 | that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r | |
197 | \r | |
198 | @param StartValue The value the performance counter starts with when it\r | |
199 | rolls over.\r | |
200 | @param EndValue The value that the performance counter ends with before\r | |
201 | it rolls over.\r | |
202 | \r | |
203 | @return The frequency in Hz.\r | |
204 | \r | |
205 | **/\r | |
206 | UINT64\r | |
207 | EFIAPI\r | |
208 | GetPerformanceCounterProperties (\r | |
209 | OUT UINT64 *StartValue, OPTIONAL\r | |
210 | OUT UINT64 *EndValue OPTIONAL\r | |
211 | )\r | |
212 | {\r | |
213 | if (StartValue != NULL) {\r | |
214 | *StartValue = (UINT64)GetApicTimerInitCount ();\r | |
2057d8c8 | 215 | }\r |
216 | \r | |
217 | if (EndValue != NULL) {\r | |
218 | *EndValue = 0;\r | |
219 | }\r | |
220 | \r | |
221 | return (UINT64) InternalX86GetTimerFrequency ();\r | |
222 | }\r | |
b9610b9c | 223 | \r |
224 | /**\r | |
225 | Converts elapsed ticks of performance counter to time in nanoseconds.\r | |
226 | \r | |
227 | This function converts the elapsed ticks of running performance counter to\r | |
228 | time value in unit of nanoseconds.\r | |
229 | \r | |
230 | @param Ticks The number of elapsed ticks of running performance counter.\r | |
231 | \r | |
232 | @return The elapsed time in nanoseconds.\r | |
233 | \r | |
234 | **/\r | |
235 | UINT64\r | |
236 | EFIAPI\r | |
237 | GetTimeInNanoSecond (\r | |
238 | IN UINT64 Ticks\r | |
239 | )\r | |
240 | {\r | |
241 | UINT64 Frequency;\r | |
242 | UINT64 NanoSeconds;\r | |
243 | UINT64 Remainder;\r | |
244 | INTN Shift;\r | |
245 | \r | |
246 | Frequency = GetPerformanceCounterProperties (NULL, NULL);\r | |
247 | \r | |
248 | //\r | |
249 | // Ticks\r | |
250 | // Time = --------- x 1,000,000,000\r | |
251 | // Frequency\r | |
252 | //\r | |
253 | NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);\r | |
254 | \r | |
255 | //\r | |
256 | // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.\r | |
257 | // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34,\r | |
258 | // i.e. highest bit set in Remainder should <= 33.\r | |
259 | //\r | |
260 | Shift = MAX (0, HighBitSet64 (Remainder) - 33);\r | |
261 | Remainder = RShiftU64 (Remainder, (UINTN) Shift);\r | |
262 | Frequency = RShiftU64 (Frequency, (UINTN) Shift);\r | |
263 | NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);\r | |
264 | \r | |
265 | return NanoSeconds;\r | |
266 | }\r |