1 /** @file
2 ACPI Timer implements one instance of Timer Library.
3
4 Copyright (c) 2013 - 2015, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 **/
14
15 #include <Base.h>
16 #include <Library/TimerLib.h>
17 #include <Library/BaseLib.h>
18 #include <Library/PcdLib.h>
19 #include <Library/PciLib.h>
20 #include <Library/IoLib.h>
21 #include <Library/DebugLib.h>
22 #include <IndustryStandard/Acpi.h>
23
24 /**
25 Internal function to retrieves the 64-bit frequency in Hz.
26
27 Internal function to retrieves the 64-bit frequency in Hz.
28
29 @return The frequency in Hz.
30
31 **/
32 UINT64
33 InternalGetPerformanceCounterFrequency (
34 VOID
35 );
36
37 /**
38 The constructor function enables ACPI IO space.
39
40 If ACPI I/O space not enabled, this function will enable it.
41 It will always return RETURN_SUCCESS.
42
43 @retval EFI_SUCCESS The constructor always returns RETURN_SUCCESS.
44
45 **/
46 RETURN_STATUS
47 EFIAPI
AcpiTimerLibConstructor(VOID)48 AcpiTimerLibConstructor (
49 VOID
50 )
51 {
52 UINTN Bus;
53 UINTN Device;
54 UINTN Function;
55 UINTN EnableRegister;
56 UINT8 EnableMask;
57
58 //
59 // ASSERT for the invalid PCD values. They must be configured to the real value.
60 //
61 ASSERT (PcdGet16 (PcdAcpiIoPciBarRegisterOffset) != 0xFFFF);
62 ASSERT (PcdGet16 (PcdAcpiIoPortBaseAddress) != 0xFFFF);
63
64 //
65 // If the register offset to the BAR for the ACPI I/O Port Base Address is 0x0000, then
66 // no PCI register programming is required to enable access to the the ACPI registers
67 // specified by PcdAcpiIoPortBaseAddress
68 //
69 if (PcdGet16 (PcdAcpiIoPciBarRegisterOffset) == 0x0000) {
70 return RETURN_SUCCESS;
71 }
72
73 //
74 // ASSERT for the invalid PCD values. They must be configured to the real value.
75 //
76 ASSERT (PcdGet8 (PcdAcpiIoPciDeviceNumber) != 0xFF);
77 ASSERT (PcdGet8 (PcdAcpiIoPciFunctionNumber) != 0xFF);
78 ASSERT (PcdGet16 (PcdAcpiIoPciEnableRegisterOffset) != 0xFFFF);
79
80 //
81 // Retrieve the PCD values for the PCI configuration space required to program the ACPI I/O Port Base Address
82 //
83 Bus = PcdGet8 (PcdAcpiIoPciBusNumber);
84 Device = PcdGet8 (PcdAcpiIoPciDeviceNumber);
85 Function = PcdGet8 (PcdAcpiIoPciFunctionNumber);
86 EnableRegister = PcdGet16 (PcdAcpiIoPciEnableRegisterOffset);
87 EnableMask = PcdGet8 (PcdAcpiIoBarEnableMask);
88
89 //
90 // If ACPI I/O space is not enabled yet, program ACPI I/O base address and enable it.
91 //
92 if ((PciRead8 (PCI_LIB_ADDRESS (Bus, Device, Function, EnableRegister) & EnableMask) != EnableMask)) {
93 PciWrite16 (
94 PCI_LIB_ADDRESS (Bus, Device, Function, PcdGet16 (PcdAcpiIoPciBarRegisterOffset)),
95 PcdGet16 (PcdAcpiIoPortBaseAddress)
96 );
97 PciOr8 (
98 PCI_LIB_ADDRESS (Bus, Device, Function, EnableRegister),
99 EnableMask
100 );
101 }
102
103 return RETURN_SUCCESS;
104 }
105
106 /**
107 Internal function to retrieve the ACPI I/O Port Base Address.
108
109 Internal function to retrieve the ACPI I/O Port Base Address.
110
111 @return The 16-bit ACPI I/O Port Base Address.
112
113 **/
114 UINT16
InternalAcpiGetAcpiTimerIoPort(VOID)115 InternalAcpiGetAcpiTimerIoPort (
116 VOID
117 )
118 {
119 UINT16 Port;
120
121 Port = PcdGet16 (PcdAcpiIoPortBaseAddress);
122
123 //
124 // If the register offset to the BAR for the ACPI I/O Port Base Address is not 0x0000, then
125 // read the PCI register for the ACPI BAR value in case the BAR has been programmed to a
126 // value other than PcdAcpiIoPortBaseAddress
127 //
128 if (PcdGet16 (PcdAcpiIoPciBarRegisterOffset) != 0x0000) {
129 Port = PciRead16 (PCI_LIB_ADDRESS (
130 PcdGet8 (PcdAcpiIoPciBusNumber),
131 PcdGet8 (PcdAcpiIoPciDeviceNumber),
132 PcdGet8 (PcdAcpiIoPciFunctionNumber),
133 PcdGet16 (PcdAcpiIoPciBarRegisterOffset)
134 ));
135 }
136
137 return (Port & PcdGet16 (PcdAcpiIoPortBaseAddressMask)) + PcdGet16 (PcdAcpiPm1TmrOffset);
138 }
139
140 /**
141 Stalls the CPU for at least the given number of ticks.
142
143 Stalls the CPU for at least the given number of ticks. It's invoked by
144 MicroSecondDelay() and NanoSecondDelay().
145
146 @param Delay A period of time to delay in ticks.
147
148 **/
149 VOID
InternalAcpiDelay(IN UINT32 Delay)150 InternalAcpiDelay (
151 IN UINT32 Delay
152 )
153 {
154 UINT16 Port;
155 UINT32 Ticks;
156 UINT32 Times;
157
158 Port = InternalAcpiGetAcpiTimerIoPort ();
159 Times = Delay >> 22;
160 Delay &= BIT22 - 1;
161 do {
162 //
163 // The target timer count is calculated here
164 //
165 Ticks = IoRead32 (Port) + Delay;
166 Delay = BIT22;
167 //
168 // Wait until time out
169 // Delay >= 2^23 could not be handled by this function
170 // Timer wrap-arounds are handled correctly by this function
171 //
172 while (((Ticks - IoRead32 (Port)) & BIT23) == 0) {
173 CpuPause ();
174 }
175 } while (Times-- > 0);
176 }
177
178 /**
179 Stalls the CPU for at least the given number of microseconds.
180
181 Stalls the CPU for the number of microseconds specified by MicroSeconds.
182
183 @param MicroSeconds The minimum number of microseconds to delay.
184
185 @return MicroSeconds
186
187 **/
188 UINTN
189 EFIAPI
MicroSecondDelay(IN UINTN MicroSeconds)190 MicroSecondDelay (
191 IN UINTN MicroSeconds
192 )
193 {
194 InternalAcpiDelay (
195 (UINT32)DivU64x32 (
196 MultU64x32 (
197 MicroSeconds,
198 ACPI_TIMER_FREQUENCY
199 ),
200 1000000u
201 )
202 );
203 return MicroSeconds;
204 }
205
206 /**
207 Stalls the CPU for at least the given number of nanoseconds.
208
209 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
210
211 @param NanoSeconds The minimum number of nanoseconds to delay.
212
213 @return NanoSeconds
214
215 **/
216 UINTN
217 EFIAPI
NanoSecondDelay(IN UINTN NanoSeconds)218 NanoSecondDelay (
219 IN UINTN NanoSeconds
220 )
221 {
222 InternalAcpiDelay (
223 (UINT32)DivU64x32 (
224 MultU64x32 (
225 NanoSeconds,
226 ACPI_TIMER_FREQUENCY
227 ),
228 1000000000u
229 )
230 );
231 return NanoSeconds;
232 }
233
234 /**
235 Retrieves the current value of a 64-bit free running performance counter.
236
237 Retrieves the current value of a 64-bit free running performance counter. The
238 counter can either count up by 1 or count down by 1. If the physical
239 performance counter counts by a larger increment, then the counter values
240 must be translated. The properties of the counter can be retrieved from
241 GetPerformanceCounterProperties().
242
243 @return The current value of the free running performance counter.
244
245 **/
246 UINT64
247 EFIAPI
GetPerformanceCounter(VOID)248 GetPerformanceCounter (
249 VOID
250 )
251 {
252 return AsmReadTsc ();
253 }
254
255 /**
256 Retrieves the 64-bit frequency in Hz and the range of performance counter
257 values.
258
259 If StartValue is not NULL, then the value that the performance counter starts
260 with immediately after is it rolls over is returned in StartValue. If
261 EndValue is not NULL, then the value that the performance counter end with
262 immediately before it rolls over is returned in EndValue. The 64-bit
263 frequency of the performance counter in Hz is always returned. If StartValue
264 is less than EndValue, then the performance counter counts up. If StartValue
265 is greater than EndValue, then the performance counter counts down. For
266 example, a 64-bit free running counter that counts up would have a StartValue
267 of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
268 that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
269
270 @param StartValue The value the performance counter starts with when it
271 rolls over.
272 @param EndValue The value that the performance counter ends with before
273 it rolls over.
274
275 @return The frequency in Hz.
276
277 **/
278 UINT64
279 EFIAPI
GetPerformanceCounterProperties(OUT UINT64 * StartValue,OPTIONAL OUT UINT64 * EndValue OPTIONAL)280 GetPerformanceCounterProperties (
281 OUT UINT64 *StartValue, OPTIONAL
282 OUT UINT64 *EndValue OPTIONAL
283 )
284 {
285 if (StartValue != NULL) {
286 *StartValue = 0;
287 }
288
289 if (EndValue != NULL) {
290 *EndValue = 0xffffffffffffffffULL;
291 }
292 return InternalGetPerformanceCounterFrequency ();
293 }
294
295 /**
296 Converts elapsed ticks of performance counter to time in nanoseconds.
297
298 This function converts the elapsed ticks of running performance counter to
299 time value in unit of nanoseconds.
300
301 @param Ticks The number of elapsed ticks of running performance counter.
302
303 @return The elapsed time in nanoseconds.
304
305 **/
306 UINT64
307 EFIAPI
GetTimeInNanoSecond(IN UINT64 Ticks)308 GetTimeInNanoSecond (
309 IN UINT64 Ticks
310 )
311 {
312 UINT64 Frequency;
313 UINT64 NanoSeconds;
314 UINT64 Remainder;
315 INTN Shift;
316
317 Frequency = GetPerformanceCounterProperties (NULL, NULL);
318
319 //
320 // Ticks
321 // Time = --------- x 1,000,000,000
322 // Frequency
323 //
324 NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);
325
326 //
327 // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.
328 // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34,
329 // i.e. highest bit set in Remainder should <= 33.
330 //
331 Shift = MAX (0, HighBitSet64 (Remainder) - 33);
332 Remainder = RShiftU64 (Remainder, (UINTN) Shift);
333 Frequency = RShiftU64 (Frequency, (UINTN) Shift);
334 NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);
335
336 return NanoSeconds;
337 }
338