--- /dev/null
+/** @file\r
+ ACPI Timer implements one instance of Timer Library.\r
+\r
+ Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>\r
+ SPDX-License-Identifier: BSD-2-Clause-Patent\r
+\r
+**/\r
+\r
+#include <PiPei.h>\r
+#include <Library/TimerLib.h>\r
+#include <Library/BaseLib.h>\r
+#include <Library/IoLib.h>\r
+#include <Library/HobLib.h>\r
+#include <Library/DebugLib.h>\r
+\r
+#include <Guid/AcpiBoardInfoGuid.h>\r
+#include <IndustryStandard/Acpi.h>\r
+\r
+#define ACPI_TIMER_COUNT_SIZE BIT24\r
+\r
+UINTN mPmTimerReg = 0;\r
+\r
+/**\r
+ The constructor function enables ACPI IO space.\r
+\r
+ If ACPI I/O space not enabled, this function will enable it.\r
+ It will always return RETURN_SUCCESS.\r
+\r
+ @retval EFI_SUCCESS The constructor always returns RETURN_SUCCESS.\r
+\r
+**/\r
+RETURN_STATUS\r
+EFIAPI\r
+AcpiTimerLibConstructor (\r
+ VOID\r
+ )\r
+{\r
+ EFI_HOB_GUID_TYPE *GuidHob;\r
+ ACPI_BOARD_INFO *pAcpiBoardInfo;\r
+\r
+ //\r
+ // Find the acpi board information guid hob\r
+ //\r
+ GuidHob = GetFirstGuidHob (&gUefiAcpiBoardInfoGuid);\r
+ ASSERT (GuidHob != NULL);\r
+\r
+ pAcpiBoardInfo = (ACPI_BOARD_INFO *)GET_GUID_HOB_DATA (GuidHob);\r
+\r
+ mPmTimerReg = (UINTN)pAcpiBoardInfo->PmTimerRegBase;\r
+\r
+ return EFI_SUCCESS;\r
+}\r
+\r
+/**\r
+ Internal function to read the current tick counter of ACPI.\r
+\r
+ Internal function to read the current tick counter of ACPI.\r
+\r
+ @return The tick counter read.\r
+\r
+**/\r
+UINT32\r
+InternalAcpiGetTimerTick (\r
+ VOID\r
+ )\r
+{\r
+ if (mPmTimerReg == 0) {\r
+ AcpiTimerLibConstructor ();\r
+ }\r
+ return IoRead32 (mPmTimerReg);\r
+}\r
+\r
+/**\r
+ Stalls the CPU for at least the given number of ticks.\r
+\r
+ Stalls the CPU for at least the given number of ticks. It's invoked by\r
+ MicroSecondDelay() and NanoSecondDelay().\r
+\r
+ @param Delay A period of time to delay in ticks.\r
+\r
+**/\r
+VOID\r
+InternalAcpiDelay (\r
+ IN UINT32 Delay\r
+ )\r
+{\r
+ UINT32 Ticks;\r
+ UINT32 Times;\r
+\r
+ Times = Delay >> 22;\r
+ Delay &= BIT22 - 1;\r
+ do {\r
+ //\r
+ // The target timer count is calculated here\r
+ //\r
+ Ticks = InternalAcpiGetTimerTick () + Delay;\r
+ Delay = BIT22;\r
+ //\r
+ // Wait until time out\r
+ // Delay >= 2^23 could not be handled by this function\r
+ // Timer wrap-arounds are handled correctly by this function\r
+ //\r
+ while (((Ticks - InternalAcpiGetTimerTick ()) & BIT23) == 0) {\r
+ CpuPause ();\r
+ }\r
+ } while (Times-- > 0);\r
+}\r
+\r
+/**\r
+ Stalls the CPU for at least the given number of microseconds.\r
+\r
+ Stalls the CPU for the number of microseconds specified by MicroSeconds.\r
+\r
+ @param MicroSeconds The minimum number of microseconds to delay.\r
+\r
+ @return MicroSeconds\r
+\r
+**/\r
+UINTN\r
+EFIAPI\r
+MicroSecondDelay (\r
+ IN UINTN MicroSeconds\r
+ )\r
+{\r
+ InternalAcpiDelay (\r
+ (UINT32)DivU64x32 (\r
+ MultU64x32 (\r
+ MicroSeconds,\r
+ ACPI_TIMER_FREQUENCY\r
+ ),\r
+ 1000000u\r
+ )\r
+ );\r
+ return MicroSeconds;\r
+}\r
+\r
+/**\r
+ Stalls the CPU for at least the given number of nanoseconds.\r
+\r
+ Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r
+\r
+ @param NanoSeconds The minimum number of nanoseconds to delay.\r
+\r
+ @return NanoSeconds\r
+\r
+**/\r
+UINTN\r
+EFIAPI\r
+NanoSecondDelay (\r
+ IN UINTN NanoSeconds\r
+ )\r
+{\r
+ InternalAcpiDelay (\r
+ (UINT32)DivU64x32 (\r
+ MultU64x32 (\r
+ NanoSeconds,\r
+ ACPI_TIMER_FREQUENCY\r
+ ),\r
+ 1000000000u\r
+ )\r
+ );\r
+ return NanoSeconds;\r
+}\r
+\r
+/**\r
+ Retrieves the current value of a 64-bit free running performance counter.\r
+\r
+ Retrieves the current value of a 64-bit free running performance counter. The\r
+ counter can either count up by 1 or count down by 1. If the physical\r
+ performance counter counts by a larger increment, then the counter values\r
+ must be translated. The properties of the counter can be retrieved from\r
+ GetPerformanceCounterProperties().\r
+\r
+ @return The current value of the free running performance counter.\r
+\r
+**/\r
+UINT64\r
+EFIAPI\r
+GetPerformanceCounter (\r
+ VOID\r
+ )\r
+{\r
+ return (UINT64)InternalAcpiGetTimerTick ();\r
+}\r
+\r
+/**\r
+ Retrieves the 64-bit frequency in Hz and the range of performance counter\r
+ values.\r
+\r
+ If StartValue is not NULL, then the value that the performance counter starts\r
+ with immediately after is it rolls over is returned in StartValue. If\r
+ EndValue is not NULL, then the value that the performance counter end with\r
+ immediately before it rolls over is returned in EndValue. The 64-bit\r
+ frequency of the performance counter in Hz is always returned. If StartValue\r
+ is less than EndValue, then the performance counter counts up. If StartValue\r
+ is greater than EndValue, then the performance counter counts down. For\r
+ example, a 64-bit free running counter that counts up would have a StartValue\r
+ of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r
+ that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r
+\r
+ @param StartValue The value the performance counter starts with when it\r
+ rolls over.\r
+ @param EndValue The value that the performance counter ends with before\r
+ it rolls over.\r
+\r
+ @return The frequency in Hz.\r
+\r
+**/\r
+UINT64\r
+EFIAPI\r
+GetPerformanceCounterProperties (\r
+ OUT UINT64 *StartValue, OPTIONAL\r
+ OUT UINT64 *EndValue OPTIONAL\r
+ )\r
+{\r
+ if (StartValue != NULL) {\r
+ *StartValue = 0;\r
+ }\r
+\r
+ if (EndValue != NULL) {\r
+ *EndValue = ACPI_TIMER_COUNT_SIZE - 1;\r
+ }\r
+\r
+ return ACPI_TIMER_FREQUENCY;\r
+}\r
+\r
+/**\r
+ Converts elapsed ticks of performance counter to time in nanoseconds.\r
+\r
+ This function converts the elapsed ticks of running performance counter to\r
+ time value in unit of nanoseconds.\r
+\r
+ @param Ticks The number of elapsed ticks of running performance counter.\r
+\r
+ @return The elapsed time in nanoseconds.\r
+\r
+**/\r
+UINT64\r
+EFIAPI\r
+GetTimeInNanoSecond (\r
+ IN UINT64 Ticks\r
+ )\r
+{\r
+ UINT64 Frequency;\r
+ UINT64 NanoSeconds;\r
+ UINT64 Remainder;\r
+ INTN Shift;\r
+\r
+ Frequency = GetPerformanceCounterProperties (NULL, NULL);\r
+\r
+ //\r
+ // Ticks\r
+ // Time = --------- x 1,000,000,000\r
+ // Frequency\r
+ //\r
+ NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);\r
+\r
+ //\r
+ // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.\r
+ // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34,\r
+ // i.e. highest bit set in Remainder should <= 33.\r
+ //\r
+ Shift = MAX (0, HighBitSet64 (Remainder) - 33);\r
+ Remainder = RShiftU64 (Remainder, (UINTN) Shift);\r
+ Frequency = RShiftU64 (Frequency, (UINTN) Shift);\r
+ NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);\r
+\r
+ return NanoSeconds;\r
+}\r
+\r
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