diff options
Diffstat (limited to 'OvmfPkg/8254TimerDxe/Timer.c')
| -rw-r--r-- | OvmfPkg/8254TimerDxe/Timer.c | 406 |
1 files changed, 0 insertions, 406 deletions
diff --git a/OvmfPkg/8254TimerDxe/Timer.c b/OvmfPkg/8254TimerDxe/Timer.c deleted file mode 100644 index 5382b01..0000000 --- a/OvmfPkg/8254TimerDxe/Timer.c +++ /dev/null @@ -1,406 +0,0 @@ -/** @file
- Timer Architectural Protocol as defined in the DXE CIS
-
-Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>
-SPDX-License-Identifier: BSD-2-Clause-Patent
-
-**/
-
-#include <Library/NestedInterruptTplLib.h>
-
-#include "Timer.h"
-
-//
-// The handle onto which the Timer Architectural Protocol will be installed
-//
-EFI_HANDLE mTimerHandle = 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;
-
-//
-// Pointer to the Legacy 8259 Protocol instance
-//
-EFI_LEGACY_8259_PROTOCOL *mLegacy8259;
-
-//
-// The notification function to call on every timer interrupt.
-// A bug in the compiler prevents us from initializing this here.
-//
-EFI_TIMER_NOTIFY mTimerNotifyFunction;
-
-//
-// The current period of the timer interrupt
-//
-volatile UINT64 mTimerPeriod = 0;
-
-//
-// Worker Functions
-//
-
-/**
- Sets the counter value for Timer #0 in a legacy 8254 timer.
-
- @param Count The 16-bit counter value to program into Timer #0 of the legacy 8254 timer.
-**/
-VOID
-SetPitCount (
- IN UINT16 Count
- )
-{
- IoWrite8 (TIMER_CONTROL_PORT, 0x36);
- IoWrite8 (TIMER0_COUNT_PORT, (UINT8)(Count & 0xff));
- IoWrite8 (TIMER0_COUNT_PORT, (UINT8)((Count >> 8) & 0xff));
-}
-
-/**
- 8254 Timer #0 Interrupt Handler.
-
- @param InterruptType The type of interrupt that occurred
- @param SystemContext A pointer to the system context when the interrupt occurred
-**/
-VOID
-EFIAPI
-TimerInterruptHandler (
- IN EFI_EXCEPTION_TYPE InterruptType,
- IN EFI_SYSTEM_CONTEXT SystemContext
- )
-{
- STATIC NESTED_INTERRUPT_STATE NestedInterruptState;
- EFI_TPL OriginalTPL;
-
- OriginalTPL = NestedInterruptRaiseTPL ();
-
- mLegacy8259->EndOfInterrupt (mLegacy8259, Efi8259Irq0);
-
- if (mTimerNotifyFunction != NULL) {
- //
- // @bug : This does not handle missed timer interrupts
- //
- mTimerNotifyFunction (mTimerPeriod);
- }
-
- NestedInterruptRestoreTPL (OriginalTPL, SystemContext, &NestedInterruptState);
-}
-
-/**
-
- 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;
-
- //
- // The basic clock is 1.19318 MHz or 0.119318 ticks per 100 ns.
- // TimerPeriod * 0.119318 = 8254 timer divisor. Using integer arithmetic
- // TimerCount = (TimerPeriod * 119318)/1000000.
- //
- // Round up to next highest integer. This guarantees that the timer is
- // equal to or slightly longer than the requested time.
- // TimerCount = ((TimerPeriod * 119318) + 500000)/1000000
- //
- // Note that a TimerCount of 0 is equivalent to a count of 65,536
- //
- // Since TimerCount is limited to 16 bits for IA32, TimerPeriod is limited
- // to 20 bits.
- //
- if (TimerPeriod == 0) {
- //
- // Disable timer interrupt for a TimerPeriod of 0
- //
- mLegacy8259->DisableIrq (mLegacy8259, Efi8259Irq0);
- } else {
- //
- // Convert TimerPeriod into 8254 counts
- //
- TimerCount = DivU64x32 (MultU64x32 (119318, (UINT32)TimerPeriod) + 500000, 1000000);
-
- //
- // Check for overflow
- //
- if (TimerCount >= 65536) {
- TimerCount = 0;
- TimerPeriod = MAX_TIMER_TICK_DURATION;
- }
-
- //
- // Program the 8254 timer with the new count value
- //
- SetPitCount ((UINT16)TimerCount);
-
- //
- // Enable timer interrupt
- //
- mLegacy8259->EnableIrq (mLegacy8259, Efi8259Irq0, FALSE);
- }
-
- //
- // 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;
-}
-
-/**
-
- 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
- )
-{
- EFI_STATUS Status;
- UINT16 IRQMask;
- EFI_TPL OriginalTPL;
-
- //
- // If the timer interrupt is enabled, then the registered handler will be invoked.
- //
- Status = mLegacy8259->GetMask (mLegacy8259, NULL, NULL, &IRQMask, NULL);
- ASSERT_EFI_ERROR (Status);
- if ((IRQMask & 0x1) == 0) {
- //
- // Invoke the registered handler
- //
- OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
-
- if (mTimerNotifyFunction != NULL) {
- //
- // @bug : This does not handle missed timer interrupts
- //
- mTimerNotifyFunction (mTimerPeriod);
- }
-
- gBS->RestoreTPL (OriginalTPL);
- } else {
- return EFI_UNSUPPORTED;
- }
-
- return EFI_SUCCESS;
-}
-
-/**
- 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
-TimerDriverInitialize (
- 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);
-
- //
- // Find the Legacy8259 protocol.
- //
- Status = gBS->LocateProtocol (&gEfiLegacy8259ProtocolGuid, NULL, (VOID **)&mLegacy8259);
- ASSERT_EFI_ERROR (Status);
-
- //
- // Force the timer to be disabled
- //
- Status = TimerDriverSetTimerPeriod (&mTimer, 0);
- ASSERT_EFI_ERROR (Status);
-
- //
- // Get the interrupt vector number corresponding to IRQ0 from the 8259 driver
- //
- TimerVector = 0;
- Status = mLegacy8259->GetVector (mLegacy8259, Efi8259Irq0, (UINT8 *)&TimerVector);
- ASSERT_EFI_ERROR (Status);
-
- //
- // Install interrupt handler for 8254 Timer #0 (ISA IRQ0)
- //
- Status = mCpu->RegisterInterruptHandler (mCpu, TimerVector, TimerInterruptHandler);
- ASSERT_EFI_ERROR (Status);
-
- //
- // 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);
-
- return Status;
-}
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