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 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 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 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 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 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 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 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 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