--- /dev/null
+/** @file\r
+ RISC-V instance of Timer Library.\r
+\r
+ Copyright (c) 2016 - 2022, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>\r
+\r
+ SPDX-License-Identifier: BSD-2-Clause-Patent\r
+\r
+**/\r
+\r
+#include <Uefi.h>\r
+#include <Library/BaseLib.h>\r
+#include <Library/DebugLib.h>\r
+#include <Library/PcdLib.h>\r
+#include <Register/RiscV64/RiscVImpl.h>\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
+InternalRiscVTimerDelay (\r
+ IN UINT32 Delay\r
+ )\r
+{\r
+ UINT32 Ticks;\r
+ UINT32 Times;\r
+\r
+ Times = Delay >> (RISCV_TIMER_COMPARE_BITS - 2);\r
+ Delay &= ((1 << (RISCV_TIMER_COMPARE_BITS - 2)) - 1);\r
+ do {\r
+ //\r
+ // The target timer count is calculated here\r
+ //\r
+ Ticks = RiscVReadTimer () + Delay;\r
+ Delay = 1 << (RISCV_TIMER_COMPARE_BITS - 2);\r
+ while (((Ticks - RiscVReadTimer ()) & (1 << (RISCV_TIMER_COMPARE_BITS - 1))) == 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
+ InternalRiscVTimerDelay (\r
+ (UINT32)DivU64x32 (\r
+ MultU64x32 (\r
+ MicroSeconds,\r
+ PcdGet64 (PcdCpuCoreCrystalClockFrequency)\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
+ InternalRiscVTimerDelay (\r
+ (UINT32)DivU64x32 (\r
+ MultU64x32 (\r
+ NanoSeconds,\r
+ PcdGet64 (PcdCpuCoreCrystalClockFrequency)\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)RiscVReadTimer ();\r
+}\r
+\r
+/**return\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 = 32 - 1;\r
+ }\r
+\r
+ return PcdGet64 (PcdCpuCoreCrystalClockFrequency);\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 NanoSeconds;\r
+ UINT32 Remainder;\r
+\r
+ //\r
+ // Ticks\r
+ // Time = --------- x 1,000,000,000\r
+ // Frequency\r
+ //\r
+ NanoSeconds = MultU64x32 (DivU64x32Remainder (Ticks, PcdGet64 (PcdCpuCoreCrystalClockFrequency), &Remainder), 1000000000u);\r
+\r
+ //\r
+ // Frequency < 0x100000000, so Remainder < 0x100000000, then (Remainder * 1,000,000,000)\r
+ // will not overflow 64-bit.\r
+ //\r
+ NanoSeconds += DivU64x32 (MultU64x32 ((UINT64)Remainder, 1000000000u), PcdGet64 (PcdCpuCoreCrystalClockFrequency));\r
+\r
+ return NanoSeconds;\r
+}\r