-----Original Message-----
From: Chao Li <lichao@loongson.cn>
Sent: Friday, January 12, 2024 4:24 PM
To: devel@edk2.groups.io
Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>; Kumar,
Rahul R <rahul.r.kumar@intel.com>; Gerd Hoffmann <kraxel@redhat.com>
Subject: [PATCH v7 11/37] UefiCpuPkg: Add LoongArch64 CPU Timer library
Add the LoongArch64 CPU Timer library, using CPUCFG 0x4 and 0x5 for
Stable Counter frequency.
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4584
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Chao Li <lichao@loongson.cn>
Acked-by: Ray Ni <ray.ni@intel.com>
---
.../BaseLoongArch64CpuTimerLib.inf | 29 ++
.../BaseLoongArch64CpuTimerLib.uni | 15 ++
.../BaseLoongArch64CpuTimerLib/CpuTimerLib.c | 251
++++++++++++++++++
UefiCpuPkg/UefiCpuPkg.dsc | 3 +
4 files changed, 298 insertions(+)
create mode 100644
UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/BaseLoongArch64CpuTim
erLib.inf
create mode 100644
UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/BaseLoongArch64CpuTim
erLib.uni
create mode 100644
UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/CpuTimerLib.c
diff --git
a/UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/BaseLoongArch64CpuT
imerLib.inf
b/UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/BaseLoongArch64CpuT
imerLib.inf
new file mode 100644
index 0000000000..8648cc2a57
--- /dev/null
+++
b/UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/BaseLoongArch64CpuT
imerLib.inf
@@ -0,0 +1,29 @@
+## @file
+# Base CPU Timer Library
+#
+# Provides base timer support using CPUCFG 0x4 and 0x5 stable counter
frequency.
+#
+# Copyright (c) 2024, Loongson Technology Corporation Limited. All rights
reserved.<BR>
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x00010029
+ BASE_NAME = BaseLoongArch64CpuTimerLib
+ FILE_GUID = 740389C7-CC44-4A2F-88DC-89D97D312E7C
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = TimerLib
+ MODULE_UNI_FILE = BaseLoongArch64CpuTimerLib.uni
+
+[Sources]
+ CpuTimerLib.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ BaseLib
+ DebugLib
+ SafeIntLib
diff --git
a/UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/BaseLoongArch64CpuT
imerLib.uni
b/UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/BaseLoongArch64CpuT
imerLib.uni
new file mode 100644
index 0000000000..f66e96e972
--- /dev/null
+++
b/UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/BaseLoongArch64CpuT
imerLib.uni
@@ -0,0 +1,15 @@
+// /** @file
+// Base CPU Timer Library
+//
+// Provides base timer support using CPUCFG 0x4 and 0x5 stable counter
frequency.
+//
+// Copyright (c) 2024, Loongson Technology Corporation Limited. All rights
reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT #language en-US "LOONGARCH CPU
Timer Library"
+
+#string STR_MODULE_DESCRIPTION #language en-US "Provides basic
timer support using CPUCFG 0x4 and 0x5 stable counter frequency."
diff --git a/UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/CpuTimerLib.c
b/UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/CpuTimerLib.c
new file mode 100644
index 0000000000..a5ae8d0185
--- /dev/null
+++ b/UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/CpuTimerLib.c
@@ -0,0 +1,251 @@
+/** @file
+ CPUCFG 0x4 and 0x5 for Stable Counter frequency instance of Timer Library.
+
+ Copyright (c) 2024, Loongson Technology Corporation Limited. All rights
reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Base.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/SafeIntLib.h>
+#include <Library/TimerLib.h>
+#include <Register/LoongArch64/Cpucfg.h>
+
+/**
+ Calculate clock frequency using CPUCFG 0x4 and 0x5 registers.
+
+ @param VOID.
+
+ @return The frequency in Hz.
+
+**/
+STATIC
+UINT64
+CalcConstFreq (
+ VOID
+ )
+{
+ UINT32 BaseFreq;
+ UINT64 ClockMultiplier;
+ UINT32 ClockDivide;
+ CPUCFG_REG4_INFO_DATA CcFreq;
+ CPUCFG_REG5_INFO_DATA CpucfgReg5Data;
+ UINT64 StableTimerFreq;
+
+ //
+ // Get the the crystal frequency corresponding to the constant
+ // frequency timer and the clock used by the timer.
+ //
+ AsmCpucfg (CPUCFG_REG4_INFO, &CcFreq.Uint32);
+
+ //
+ // Get the multiplication factor and frequency division factor
+ // corresponding to the constant frequency timer and the clock
+ // used by the timer.
+ //
+ AsmCpucfg (CPUCFG_REG5_INFO, &CpucfgReg5Data.Uint32);
+
+ BaseFreq = CcFreq.Bits.CC_FREQ;
+ ClockMultiplier = CpucfgReg5Data.Bits.CC_MUL & 0xFFFF;
+ ClockDivide = CpucfgReg5Data.Bits.CC_DIV & 0xFFFF;
+
+ if ((BaseFreq == 0x0) || (ClockMultiplier == 0x0) || (ClockDivide == 0x0)) {
+ DEBUG ((
+ DEBUG_ERROR,
+ "LoongArch Stable Timer is not available in the CPU, hence this library
cannot be used.\n"
+ ));
+ ASSERT (FALSE);
+ CpuDeadLoop ();
+ }
+
+ StableTimerFreq = ((ClockMultiplier * BaseFreq) / ClockDivide);
+
+ if (StableTimerFreq == 0x0) {
+ ASSERT (FALSE);
+ }
+
+ return StableTimerFreq;
+}
+
+/**
+ 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
+ )
+{
+ UINT64 CurrentTicks, ExceptedTicks, Remaining;
+ RETURN_STATUS Status;
+
+ Status = SafeUint64Mult (MicroSeconds, CalcConstFreq (), &Remaining);
+ ASSERT_RETURN_ERROR (Status);
+
+ ExceptedTicks = DivU64x32 (Remaining, 1000000U);
+ CurrentTicks = AsmReadStableCounter ();
+ ExceptedTicks += CurrentTicks;
+
+ do {
+ CurrentTicks = AsmReadStableCounter ();
+ } while (CurrentTicks < ExceptedTicks);
+
+ 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
+ )
+{
+ UINTN MicroSeconds;
+
+ // Round up to 1us Tick Number
+ MicroSeconds = NanoSeconds / 1000;
+ MicroSeconds += ((NanoSeconds % 1000) == 0) ? 0 : 1;
+
+ MicroSecondDelay (MicroSeconds);
+
+ return NanoSeconds;
+}
+
+/**
+ Retrieves the current value of a 64-bit free running Stable Counter.
+
+ The LoongArch defines a constant frequency timer, whose main body is a
+ 64-bit counter called StableCounter. StableCounter is set to 0 after
+ reset, and then increments by 1 every counting clock cycle. When the
+ count reaches all 1s, it automatically wraps around to 0 and continues
+ to increment.
+ The properties of the Stable Counter can be retrieved from
+ GetPerformanceCounterProperties().
+
+ @return The current value of the Stable Counter.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounter (
+ VOID
+ )
+{
+ //
+ // Just return the value of Stable Counter.
+ //
+ return AsmReadStableCounter ();
+}
+
+/**
+ Retrieves the 64-bit frequency in Hz and the range of Stable Counter
+ values.
+
+ If StartValue is not NULL, then the value that the stbale counter starts
+ with immediately after is it rolls over is returned in StartValue. If
+ EndValue is not NULL, then the value that the stable counter end with
+ immediately before it rolls over is returned in EndValue. The 64-bit
+ frequency of the system frequency in Hz is always returned.
+
+ @param StartValue The value the stable counter starts with when it
+ rolls over.
+ @param EndValue The value that the stable 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 = 0xFFFFFFFFFFFFFFFFULL;
+ }
+
+ return CalcConstFreq ();
+}
+
+/**
+ 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 Frequency;
+ UINT64 NanoSeconds;
+ UINT64 Remainder;
+ INTN Shift;
+ RETURN_STATUS Status;
+
+ Frequency = GetPerformanceCounterProperties (NULL, NULL);
+
+ //
+ // Ticks
+ // Time = --------- x 1,000,000,000
+ // Frequency
+ //
+ Status = SafeUint64Mult (
+ DivU64x64Remainder (Ticks, Frequency, &Remainder),
+ 1000000000u,
+ &NanoSeconds
+ );
+
+ //
+ // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.
+ // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should <
2^(64-30) = 2^34,
+ // i.e. highest bit set in Remainder should <= 33.
+ //
+ Shift = MAX (0, HighBitSet64 (Remainder) - 33);
+ Remainder = RShiftU64 (Remainder, (UINTN)Shift);
+ Frequency = RShiftU64 (Frequency, (UINTN)Shift);
+
+ Status = SafeUint64Add (
+ NanoSeconds,
+ DivU64x64Remainder (
+ MultU64x32 (Remainder, 1000000000u),
+ Frequency,
+ NULL
+ ),
+ &NanoSeconds
+ );
+ ASSERT_RETURN_ERROR (Status);
+
+ return NanoSeconds;
+}
diff --git a/UefiCpuPkg/UefiCpuPkg.dsc b/UefiCpuPkg/UefiCpuPkg.dsc
index 28eed85bce..a977884c3d 100644
--- a/UefiCpuPkg/UefiCpuPkg.dsc
+++ b/UefiCpuPkg/UefiCpuPkg.dsc
@@ -207,5 +207,8 @@
UefiCpuPkg/CpuTimerDxeRiscV64/CpuTimerDxeRiscV64.inf
UefiCpuPkg/CpuDxeRiscV64/CpuDxeRiscV64.inf
+[Components.LOONGARCH64]
+
UefiCpuPkg/Library/BaseLoongArch64CpuTimerLib/BaseLoongArch64CpuTim
erLib.inf
+
[BuildOptions]
*_*_*_CC_FLAGS = -D DISABLE_NEW_DEPRECATED_INTERFACES
--
2.27.0