[edk2-devel] [PATCH 04/79] ProcessorPkg/Library: Add RISC-V timer library
Abner Chang
abner.chang at hpe.com
Sat Jan 8 04:10:24 UTC 2022
(This is migrated from edk2-platforms:Silicon/RISC-V)
Timer library for RISC-V.
Signed-off-by: Abner Chang <abner.chang at hpe.com>
Co-authored-by: Gilbert Chen <gilbert.chen at hpe.com>
Reviewed-by: Leif Lindholm <leif.lindholm at linaro.org>
Cc: Leif Lindholm <leif.lindholm at linaro.org>
Cc: Gilbert Chen <gilbert.chen at hpe.com>
---
.../RiscVTimerLib/BaseRiscVTimerLib.inf | 34 +++
.../Library/RiscVTimerLib/RiscVTimerLib.c | 199 ++++++++++++++++++
2 files changed, 233 insertions(+)
create mode 100644 Silicon/RISC-V/ProcessorPkg/Library/RiscVTimerLib/BaseRiscVTimerLib.inf
create mode 100644 Silicon/RISC-V/ProcessorPkg/Library/RiscVTimerLib/RiscVTimerLib.c
diff --git a/Silicon/RISC-V/ProcessorPkg/Library/RiscVTimerLib/BaseRiscVTimerLib.inf b/Silicon/RISC-V/ProcessorPkg/Library/RiscVTimerLib/BaseRiscVTimerLib.inf
new file mode 100644
index 0000000000..c914d3b4b6
--- /dev/null
+++ b/Silicon/RISC-V/ProcessorPkg/Library/RiscVTimerLib/BaseRiscVTimerLib.inf
@@ -0,0 +1,34 @@
+## @file
+# RISC-V Timer Library Instance.
+#
+# Copyright (c) 2016 - 2019, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x0001001b
+ BASE_NAME = BaseRiscVTimerLib
+ FILE_GUID = F0450728-3221-488E-8C63-BD3A8DF500E2
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = TimerLib
+
+[Sources]
+ RiscVTimerLib.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+ Silicon/RISC-V/ProcessorPkg/RiscVProcessorPkg.dec
+
+[Pcd]
+ gUefiRiscVPkgTokenSpaceGuid.PcdRiscVMachineTimerTickInNanoSecond
+ gUefiRiscVPkgTokenSpaceGuid.PcdRiscVMachineTimerFrequencyInHerz
+
+[LibraryClasses]
+ BaseLib
+ PcdLib
+ RiscVCpuLib
+ RiscVPlatformTimerLib
+
diff --git a/Silicon/RISC-V/ProcessorPkg/Library/RiscVTimerLib/RiscVTimerLib.c b/Silicon/RISC-V/ProcessorPkg/Library/RiscVTimerLib/RiscVTimerLib.c
new file mode 100644
index 0000000000..97fe2aef4b
--- /dev/null
+++ b/Silicon/RISC-V/ProcessorPkg/Library/RiscVTimerLib/RiscVTimerLib.c
@@ -0,0 +1,199 @@
+/** @file
+ RISC-V instance of Timer Library.
+
+ Copyright (c) 2016 - 2019, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
+#include <Library/RiscVCpuLib.h>
+
+/**
+ Stalls the CPU for at least the given number of ticks.
+
+ Stalls the CPU for at least the given number of ticks. It's invoked by
+ MicroSecondDelay() and NanoSecondDelay().
+
+ @param Delay A period of time to delay in ticks.
+
+**/
+VOID
+InternalRiscVTimerDelay (
+ IN UINT32 Delay
+ )
+{
+ UINT32 Ticks;
+ UINT32 Times;
+
+ Times = Delay >> (RISCV_TIMER_COMPARE_BITS - 2);
+ Delay &= (( 1 << (RISCV_TIMER_COMPARE_BITS - 2)) - 1);
+ do {
+ //
+ // The target timer count is calculated here
+ //
+ Ticks = RiscVReadMachineTimer () + Delay;
+ Delay = 1 << (RISCV_TIMER_COMPARE_BITS - 2);
+ while (((Ticks - RiscVReadMachineTimer ()) & ( 1 << (RISCV_TIMER_COMPARE_BITS - 1))) == 0) {
+ CpuPause ();
+ }
+ } while (Times-- > 0);
+}
+
+/**
+ Stalls the CPU for at least the given number of microseconds.
+
+ Stalls the CPU for the number of microseconds specified by MicroSeconds.
+
+ @param MicroSeconds The minimum number of microseconds to delay.
+
+ @return MicroSeconds
+
+**/
+UINTN
+EFIAPI
+MicroSecondDelay (
+ IN UINTN MicroSeconds
+ )
+{
+ InternalRiscVTimerDelay (
+ (UINT32)DivU64x32 (
+ MultU64x32 (
+ MicroSeconds,
+ PcdGet64 (PcdRiscVMachineTimerFrequencyInHerz)
+ ),
+ 1000000u
+ )
+ );
+ return MicroSeconds;
+}
+
+/**
+ Stalls the CPU for at least the given number of nanoseconds.
+
+ Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
+
+ @param NanoSeconds The minimum number of nanoseconds to delay.
+
+ @return NanoSeconds
+
+**/
+UINTN
+EFIAPI
+NanoSecondDelay (
+ IN UINTN NanoSeconds
+ )
+{
+ InternalRiscVTimerDelay (
+ (UINT32)DivU64x32 (
+ MultU64x32 (
+ NanoSeconds,
+ PcdGet64 (PcdRiscVMachineTimerFrequencyInHerz)
+ ),
+ 1000000000u
+ )
+ );
+ return NanoSeconds;
+}
+
+/**
+ Retrieves the current value of a 64-bit free running performance counter.
+
+ Retrieves the current value of a 64-bit free running performance counter. The
+ counter can either count up by 1 or count down by 1. If the physical
+ performance counter counts by a larger increment, then the counter values
+ must be translated. The properties of the counter can be retrieved from
+ GetPerformanceCounterProperties().
+
+ @return The current value of the free running performance counter.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounter (
+ VOID
+ )
+{
+ return (UINT64)RiscVReadMachineTimer ();
+}
+
+/**return
+ Retrieves the 64-bit frequency in Hz and the range of performance counter
+ values.
+
+ If StartValue is not NULL, then the value that the performance counter starts
+ with immediately after is it rolls over is returned in StartValue. If
+ EndValue is not NULL, then the value that the performance counter end with
+ immediately before it rolls over is returned in EndValue. The 64-bit
+ frequency of the performance counter in Hz is always returned. If StartValue
+ is less than EndValue, then the performance counter counts up. If StartValue
+ is greater than EndValue, then the performance counter counts down. For
+ example, a 64-bit free running counter that counts up would have a StartValue
+ of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
+ that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
+
+ @param StartValue The value the performance counter starts with when it
+ rolls over.
+ @param EndValue The value that the performance counter ends with before
+ it rolls over.
+
+ @return The frequency in Hz.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounterProperties (
+ OUT UINT64 *StartValue, OPTIONAL
+ OUT UINT64 *EndValue OPTIONAL
+ )
+{
+ if (StartValue != NULL) {
+ *StartValue = 0;
+ }
+
+ if (EndValue != NULL) {
+ *EndValue = 32 - 1;
+ }
+
+ return PcdGet64 (PcdRiscVMachineTimerFrequencyInHerz);
+}
+
+/**
+ Converts elapsed ticks of performance counter to time in nanoseconds.
+
+ This function converts the elapsed ticks of running performance counter to
+ time value in unit of nanoseconds.
+
+ @param Ticks The number of elapsed ticks of running performance counter.
+
+ @return The elapsed time in nanoseconds.
+
+**/
+UINT64
+EFIAPI
+GetTimeInNanoSecond (
+ IN UINT64 Ticks
+ )
+{
+ UINT64 NanoSeconds;
+ UINT32 Remainder;
+
+ //
+ // Ticks
+ // Time = --------- x 1,000,000,000
+ // Frequency
+ //
+ NanoSeconds = MultU64x32 (DivU64x32Remainder (Ticks, PcdGet64 (PcdRiscVMachineTimerFrequencyInHerz), &Remainder), 1000000000u);
+
+ //
+ // Frequency < 0x100000000, so Remainder < 0x100000000, then (Remainder * 1,000,000,000)
+ // will not overflow 64-bit.
+ //
+ NanoSeconds += DivU64x32 (MultU64x32 ((UINT64) Remainder, 1000000000u), PcdGet64 (PcdRiscVMachineTimerFrequencyInHerz));
+
+ return NanoSeconds;
+}
--
2.31.1
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