Add a CPU timer driver named StableTimerDxe, which proviedes
EFI_TIMER_ARCH_PROTOCOL for LoongArch.
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4584
Cc: Ard Biesheuvel <ardb+tianoc...@kernel.org>
Cc: Jiewen Yao <jiewen....@intel.com>
Cc: Jordan Justen <jordan.l.jus...@intel.com>
Cc: Gerd Hoffmann <kra...@redhat.com>
Cc: Bibo Mao <maob...@loongson.cn>
Cc: Dongyan Qian <qiandong...@loongson.cn>
Signed-off-by: Chao Li <lic...@loongson.cn>
Co-authored-by: Baoqi Zhang <zhangba...@loongson.cn>
---
.../Drivers/StableTimerDxe/Timer.c | 381 ++++++++++++++++++
.../Drivers/StableTimerDxe/Timer.h | 127 ++++++
.../Drivers/StableTimerDxe/TimerDxe.inf | 41 ++
3 files changed, 549 insertions(+)
create mode 100644 OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/Timer.c
create mode 100644 OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/Timer.h
create mode 100644 OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/TimerDxe.inf
diff --git a/OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/Timer.c
b/OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/Timer.c
new file mode 100644
index 0000000000..0e0f10970a
--- /dev/null
+++ b/OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/Timer.c
@@ -0,0 +1,381 @@
+/** @file
+ Timer Architectural Protocol as defined in the DXE CIS
+
+ Copyright (c) 2024 Loongson Technology Corporation Limited. All rights
reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Protocol/Cpu.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/TimerLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Register/LoongArch64/Csr.h>
+#include "Timer.h"
+
+//
+// The handle onto which the Timer Architectural Protocol will be installed
+//
+EFI_HANDLE mTimerHandle = NULL;
+EFI_EVENT EfiExitBootServicesEvent = (EFI_EVENT)NULL;
+
+//
+// The Timer Architectural Protocol that this driver produces
+//
+EFI_TIMER_ARCH_PROTOCOL mTimer = {
+ TimerDriverRegisterHandler,
+ TimerDriverSetTimerPeriod,
+ TimerDriverGetTimerPeriod,
+ TimerDriverGenerateSoftInterrupt
+};
+
+//
+// Pointer to the CPU Architectural Protocol instance
+//
+EFI_CPU_ARCH_PROTOCOL *mCpu;
+
+//
+// The notification function to call on every timer interrupt.
+// A bug in the compiler prevents us from initializing this here.
+//
+EFI_TIMER_NOTIFY mTimerNotifyFunction;
+
+/**
+ Sets the counter value for timer.
+
+ @param Count The 16-bit counter value to program into stable timer.
+
+ @retval VOID
+**/
+VOID
+SetPitCount (
+ IN UINT64 Count
+ )
+{
+ if (Count <= 4) {
+ return;
+ }
+
+ Count &= LOONGARCH_CSR_TMCFG_TIMEVAL;
+ Count |= LOONGARCH_CSR_TMCFG_EN | LOONGARCH_CSR_TMCFG_PERIOD;
+ CsrWrite (LOONGARCH_CSR_TMCFG, Count);
+}
+
+/**
+ Timer Interrupt Handler.
+
+ @param InterruptType The type of interrupt that occurred
+ @param SystemContext A pointer to the system context when the interrupt
occurred
+
+ @retval VOID
+**/
+VOID
+EFIAPI
+TimerInterruptHandler (
+ IN EFI_EXCEPTION_TYPE InterruptType,
+ IN EFI_SYSTEM_CONTEXT SystemContext
+ )
+{
+ EFI_TPL OriginalTPL;
+
+ OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
+
+ //
+ // Clear interrupt.
+ //
+ CsrWrite (LOONGARCH_CSR_TINTCLR, 0x1);
+
+ if (mTimerNotifyFunction != NULL) {
+ //
+ // @bug : This does not handle missed timer interrupts
+ //
+ mTimerNotifyFunction (mTimerPeriod);
+ }
+
+ gBS->RestoreTPL (OriginalTPL);
+}
+
+/**
+ This function registers the handler NotifyFunction so it is called every time
+ the timer interrupt fires. It also passes the amount of time since the last
+ handler call to the NotifyFunction. If NotifyFunction is NULL, then the
+ handler is unregistered. If the handler is registered, then EFI_SUCCESS is
+ returned. If the CPU does not support registering a timer interrupt handler,
+ then EFI_UNSUPPORTED is returned. If an attempt is made to register a
handler
+ when a handler is already registered, then EFI_ALREADY_STARTED is returned.
+ If an attempt is made to unregister a handler when a handler is not
registered,
+ then EFI_INVALID_PARAMETER is returned. If an error occurs attempting to
+ register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
+ is returned.
+
+ @param This The EFI_TIMER_ARCH_PROTOCOL instance.
+ @param NotifyFunction The function to call when a timer interrupt fires.
This
+ function executes at TPL_HIGH_LEVEL. The DXE Core
will
+ register a handler for the timer interrupt, so it
can know
+ how much time has passed. This information is used
to
+ signal timer based events. NULL will unregister the
handler.
+
+ @retval EFI_SUCCESS The timer handler was registered.
+ @retval EFI_UNSUPPORTED The platform does not support timer
interrupts.
+ @retval EFI_ALREADY_STARTED NotifyFunction is not NULL, and a
handler is already
+ registered.
+ @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler
was not
+ previously registered.
+ @retval EFI_DEVICE_ERROR The timer handler could not be
registered.
+**/
+EFI_STATUS
+EFIAPI
+TimerDriverRegisterHandler (
+ IN EFI_TIMER_ARCH_PROTOCOL *This,
+ IN EFI_TIMER_NOTIFY NotifyFunction
+ )
+{
+ //
+ // Check for invalid parameters
+ //
+ if ((NotifyFunction == NULL) && (mTimerNotifyFunction == NULL)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if ((NotifyFunction != NULL) && (mTimerNotifyFunction != NULL)) {
+ return EFI_ALREADY_STARTED;
+ }
+
+ mTimerNotifyFunction = NotifyFunction;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ This function adjusts the period of timer interrupts to the value specified
+ by TimerPeriod. If the timer period is updated, then the selected timer
+ period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If
+ the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
+ If an error occurs while attempting to update the timer period, then the
+ timer hardware will be put back in its state prior to this call, and
+ EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt
+ is disabled. This is not the same as disabling the CPU's interrupts.
+ Instead, it must either turn off the timer hardware, or it must adjust the
+ interrupt controller so that a CPU interrupt is not generated when the timer
+ interrupt fires.
+
+ @param This The EFI_TIMER_ARCH_PROTOCOL instance.
+ @param TimerPeriod The rate to program the timer interrupt in 100 nS
units. If
+ the timer hardware is not programmable, then
EFI_UNSUPPORTED is
+ returned. If the timer is programmable, then the
timer period
+ will be rounded up to the nearest timer period that
is supported
+ by the timer hardware. If TimerPeriod is set to 0,
then the
+ timer interrupts will be disabled.
+
+ @retval EFI_SUCCESS The timer period was changed.
+ @retval EFI_UNSUPPORTED The platform cannot change the period of
the timer interrupt.
+ @retval EFI_DEVICE_ERROR The timer period could not be changed due
to a device error.
+**/
+EFI_STATUS
+EFIAPI
+TimerDriverSetTimerPeriod (
+ IN EFI_TIMER_ARCH_PROTOCOL *This,
+ IN UINT64 TimerPeriod
+ )
+{
+ UINT64 TimerCount;
+
+ if (TimerPeriod == 0) {
+ //
+ // Disable timer interrupt for a TimerPeriod of 0
+ //
+ mCpu->DisableInterrupt (mCpu);
+ } else {
+ TimerCount = TimerPeriod * GetPerformanceCounterProperties (NULL, NULL) /
10000000ULL;
+
+ if (TimerCount >= BIT48) {
+ TimerCount = 0;
+ }
+
+ //
+ // Program the stable timer with the new count value
+ //
+ mTimerTicks = TimerCount;
+ SetPitCount (TimerCount);
+
+ //
+ // Enable timer interrupt
+ //
+ mCpu->EnableInterrupt (mCpu);
+ }
+
+ //
+ // Save the new timer period
+ //
+ mTimerPeriod = TimerPeriod;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ This function retrieves the period of timer interrupts in 100 ns units,
+ returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod
+ is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is
+ returned, then the timer is currently disabled.
+
+ @param This The EFI_TIMER_ARCH_PROTOCOL instance.
+ @param TimerPeriod A pointer to the timer period to retrieve in 100 ns
units. If
+ 0 is returned, then the timer is currently disabled.
+
+ @retval EFI_SUCCESS The timer period was returned in TimerPeriod.
+ @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
+**/
+EFI_STATUS
+EFIAPI
+TimerDriverGetTimerPeriod (
+ IN EFI_TIMER_ARCH_PROTOCOL *This,
+ OUT UINT64 *TimerPeriod
+ )
+{
+ if (TimerPeriod == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ *TimerPeriod = mTimerPeriod;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Disable the timer
+ DXE Core will disable the timer after all the event handlers have run.
+
+ @param[in] Event The Event that is being processed
+ @param[in] Context Event Context
+**/
+VOID
+EFIAPI
+ExitBootServicesEvent (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ /*
+ * Disable timer interrupt when exiting boot service
+ */
+ CsrWrite (LOONGARCH_CSR_TMCFG, 0x0);
+}
+
+/**
+ This function generates a soft timer interrupt. If the platform does not
support soft
+ timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS
is returned.
+ If a handler has been registered through the
EFI_TIMER_ARCH_PROTOCOL.RegisterHandler ()
+ service, then a soft timer interrupt will be generated. If the timer
interrupt is
+ enabled when this service is called, then the registered handler will be
invoked. The
+ registered handler should not be able to distinguish a hardware-generated
timer
+ interrupt from a software-generated timer interrupt.
+
+ @param This The EFI_TIMER_ARCH_PROTOCOL instance.
+
+ @retval EFI_SUCCESS The soft timer interrupt was generated.
+ @retval EFI_UNSUPPORTED The platform does not support the generation of
soft timer interrupts.
+**/
+EFI_STATUS
+EFIAPI
+TimerDriverGenerateSoftInterrupt (
+ IN EFI_TIMER_ARCH_PROTOCOL *This
+ )
+{
+ return EFI_UNSUPPORTED;
+}
+
+/**
+ Initialize the Timer Architectural Protocol driver
+
+ @param ImageHandle ImageHandle of the loaded driver
+ @param SystemTable Pointer to the System Table
+
+ @retval EFI_SUCCESS Timer Architectural Protocol created
+ @retval EFI_OUT_OF_RESOURCES Not enough resources available to initialize
driver.
+ @retval EFI_DEVICE_ERROR A device error occurred attempting to
initialize the driver.
+**/
+EFI_STATUS
+EFIAPI
+StableTimerDriverInitialize (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+ UINT32 TimerVector;
+
+ //
+ // Initialize the pointer to our notify function.
+ //
+ mTimerNotifyFunction = NULL;
+
+ //
+ // Make sure the Timer Architectural Protocol is not already installed in
the system
+ //
+ ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid);
+
+ //
+ // Find the CPU architectural protocol.
+ //
+ Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID
**)&mCpu);
+ ASSERT_EFI_ERROR (Status);
+
+ //
+ // Force the timer to be disabled
+ //
+ Status = TimerDriverSetTimerPeriod (&mTimer, 0);
+ ASSERT_EFI_ERROR (Status);
+
+ //
+ // Calculate const frequence
+ //
+ DEBUG ((
+ DEBUG_INFO,
+ "===========Stable timer freq %d Hz=============\n",
+ GetPerformanceCounterProperties (NULL, NULL)
+ ));
+
+ //
+ // Install interrupt handler for Stable Timer #0 (ISA IRQ0)
+ //
+ TimerVector = EXCEPT_LOONGARCH_INT_TIMER;
+ Status = mCpu->RegisterInterruptHandler (mCpu, TimerVector,
TimerInterruptHandler);
+ ASSERT_EFI_ERROR (Status);
+
+ //
+ // Enable TI local timer interrupt
+ //
+ EnableLocalInterrupts (1 << EXCEPT_LOONGARCH_INT_TIMER);
+
+ //
+ // Force the timer to be enabled at its default period
+ //
+ Status = TimerDriverSetTimerPeriod (&mTimer, DEFAULT_TIMER_TICK_DURATION);
+ ASSERT_EFI_ERROR (Status);
+
+ //
+ // Install the Timer Architectural Protocol onto a new handle
+ //
+ Status = gBS->InstallMultipleProtocolInterfaces (
+ &mTimerHandle,
+ &gEfiTimerArchProtocolGuid,
+ &mTimer,
+ NULL
+ );
+
+ ASSERT_EFI_ERROR (Status);
+
+ // Register for an ExitBootServicesEvent
+ Status = gBS->CreateEvent (
+ EVT_SIGNAL_EXIT_BOOT_SERVICES,
+ TPL_NOTIFY,
+ ExitBootServicesEvent,
+ NULL,
+ &EfiExitBootServicesEvent
+ );
+ ASSERT_EFI_ERROR (Status);
+
+ return Status;
+}
diff --git a/OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/Timer.h
b/OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/Timer.h
new file mode 100644
index 0000000000..5efccdfa44
--- /dev/null
+++ b/OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/Timer.h
@@ -0,0 +1,127 @@
+/** @file
+ Private data structures
+
+ Copyright (c) 2024 Loongson Technology Corporation Limited. All rights
reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef TIMER_H_
+#define TIMER_H_
+
+#include <Protocol/Timer.h>
+
+#define DEFAULT_TIMER_TICK_DURATION 100000 // 10ms = 100000 100 ns units
+
+//
+// The current period of the timer interrupt
+//
+volatile UINT64 mTimerPeriod = 0;
+volatile UINT64 mTimerTicks = 0;
+
+/**
+ This function adjusts the period of timer interrupts to the value specified
+ by TimerPeriod. If the timer period is updated, then the selected timer
+ period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If
+ the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
+ If an error occurs while attempting to update the timer period, then the
+ timer hardware will be put back in its state prior to this call, and
+ EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt
+ is disabled. This is not the same as disabling the CPU's interrupts.
+ Instead, it must either turn off the timer hardware, or it must adjust the
+ interrupt controller so that a CPU interrupt is not generated when the timer
+ interrupt fires.
+
+ @param This The EFI_TIMER_ARCH_PROTOCOL instance.
+ @param NotifyFunction The rate to program the timer interrupt in 100 nS
units. If
+ the timer hardware is not programmable, then
EFI_UNSUPPORTED is
+ returned. If the timer is programmable, then the
timer period
+ will be rounded up to the nearest timer period that
is supported
+ by the timer hardware. If TimerPeriod is set to 0,
then the
+ timer interrupts will be disabled.
+
+ @retval EFI_SUCCESS The timer period was changed.
+ @retval EFI_UNSUPPORTED The platform cannot change the period of
the timer interrupt.
+ @retval EFI_DEVICE_ERROR The timer period could not be changed due
to a device error.
+**/
+EFI_STATUS
+EFIAPI
+TimerDriverRegisterHandler (
+ IN EFI_TIMER_ARCH_PROTOCOL *This,
+ IN EFI_TIMER_NOTIFY NotifyFunction
+ );
+
+/**
+ This function adjusts the period of timer interrupts to the value specified
+ by TimerPeriod. If the timer period is updated, then the selected timer
+ period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If
+ the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
+ If an error occurs while attempting to update the timer period, then the
+ timer hardware will be put back in its state prior to this call, and
+ EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt
+ is disabled. This is not the same as disabling the CPU's interrupts.
+ Instead, it must either turn off the timer hardware, or it must adjust the
+ interrupt controller so that a CPU interrupt is not generated when the timer
+ interrupt fires.
+
+ @param This The EFI_TIMER_ARCH_PROTOCOL instance.
+ @param TimerPeriod The rate to program the timer interrupt in 100 nS
units. If
+ the timer hardware is not programmable, then
EFI_UNSUPPORTED is
+ returned. If the timer is programmable, then the
timer period
+ will be rounded up to the nearest timer period that
is supported
+ by the timer hardware. If TimerPeriod is set to 0,
then the
+ timer interrupts will be disabled.
+
+ @retval EFI_SUCCESS The timer period was changed.
+ @retval EFI_UNSUPPORTED The platform cannot change the period of
the timer interrupt.
+ @retval EFI_DEVICE_ERROR The timer period could not be changed due
to a device error.
+**/
+EFI_STATUS
+EFIAPI
+TimerDriverSetTimerPeriod (
+ IN EFI_TIMER_ARCH_PROTOCOL *This,
+ IN UINT64 TimerPeriod
+ );
+
+/**
+ This function retrieves the period of timer interrupts in 100 ns units,
+ returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod
+ is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is
+ returned, then the timer is currently disabled.
+
+ @param This The EFI_TIMER_ARCH_PROTOCOL instance.
+ @param TimerPeriod A pointer to the timer period to retrieve in 100 ns
units. If
+ 0 is returned, then the timer is currently disabled.
+
+ @retval EFI_SUCCESS The timer period was returned in TimerPeriod.
+ @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
+**/
+EFI_STATUS
+EFIAPI
+TimerDriverGetTimerPeriod (
+ IN EFI_TIMER_ARCH_PROTOCOL *This,
+ OUT UINT64 *TimerPeriod
+ );
+
+/**
+ This function generates a soft timer interrupt. If the platform does not
support soft
+ timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS
is returned.
+ If a handler has been registered through the
EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
+ service, then a soft timer interrupt will be generated. If the timer
interrupt is
+ enabled when this service is called, then the registered handler will be
invoked. The
+ registered handler should not be able to distinguish a hardware-generated
timer
+ interrupt from a software-generated timer interrupt.
+
+ @param This The EFI_TIMER_ARCH_PROTOCOL instance.
+
+ @retval EFI_SUCCESS The soft timer interrupt was generated.
+ @retval EFI_UNSUPPORTED The platform does not support the generation of
soft timer interrupts.
+**/
+EFI_STATUS
+EFIAPI
+TimerDriverGenerateSoftInterrupt (
+ IN EFI_TIMER_ARCH_PROTOCOL *This
+ );
+
+#endif // TIMER_H_
diff --git a/OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/TimerDxe.inf
b/OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/TimerDxe.inf
new file mode 100644
index 0000000000..7548a1df46
--- /dev/null
+++ b/OvmfPkg/LoongArchVirt/Drivers/StableTimerDxe/TimerDxe.inf
@@ -0,0 +1,41 @@
+## @file
+# Stable timer driver that provides Timer Arch protocol.
+#
+# Copyright (c) 2024 Loongson Technology Corporation Limited. All rights
reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+[Defines]
+ INF_VERSION = 1.29
+ BASE_NAME = Timer
+ MODULE_UNI_FILE = Timer.uni
+ FILE_GUID = AEBE2648-47A9-40FA-83FD-06AA88443BB2
+ MODULE_TYPE = DXE_DRIVER
+ VERSION_STRING = 1.0
+ ENTRY_POINT = StableTimerDriverInitialize
+
+#
+# VALID_ARCHITECTURES = LOONGARCH64
+#
+
+[Sources]
+ Timer.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ BaseLib
+ DebugLib
+ IoLib
+ TimerLib
+ UefiBootServicesTableLib
+ UefiDriverEntryPoint
+
+[Protocols]
+ gEfiCpuArchProtocolGuid ## CONSUMES
+ gEfiTimerArchProtocolGuid ## PRODUCES
+
+[depex]
+ gEfiCpuArchProtocolGuid
