/** @file
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Library that contains common parts of WdtPei and WdtDxe. Not a standalone module.
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Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#include <Uefi/UefiBaseType.h>
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#include <Library/IoLib.h>
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#include <Library/DebugLib.h>
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#include <PchAccess.h>
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#include <Library/PchCycleDecodingLib.h>
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#include <Library/MmPciLib.h>
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GLOBAL_REMOVE_IF_UNREFERENCED UINT8 mAllowExpectedReset = 0;
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/**
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Reads LPC bridge to get Watchdog Timer address
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@retval UINT32 Watchdog's address
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**/
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UINT32
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WdtGetAddress (
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VOID
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)
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{
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UINT32 Address;
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UINT16 ABase;
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PchAcpiBaseGet (&ABase);
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Address = ABase + R_PCH_OC_WDT_CTL;
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return Address;
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}
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/**
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Reloads WDT with new timeout value and starts it. Also sets Unexpected Reset bit, which
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causes the next reset to be treated as watchdog expiration - unless AllowKnownReset()
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function was called too.
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@param[in] TimeoutValue Time in seconds before WDT times out. Supported range = 1 - 1024.
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@retval EFI_SUCCESS if everything's OK
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@retval EFI_INVALID_PARAMETER if TimeoutValue parameter is wrong
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**/
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EFI_STATUS
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EFIAPI
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WdtReloadAndStart (
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IN UINT32 TimeoutValue
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)
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{
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UINT32 Readback;
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DEBUG ((DEBUG_INFO, "\n(Wdt) ReloadAndStartTimer(%d)\n", TimeoutValue));
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if ((TimeoutValue > B_PCH_OC_WDT_CTL_TOV_MASK) || (TimeoutValue == 0)) {
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return EFI_INVALID_PARAMETER;
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}
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Readback = IoRead32 (WdtGetAddress ());
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Readback |= (B_PCH_OC_WDT_CTL_EN | B_PCH_OC_WDT_CTL_FORCE_ALL | B_PCH_OC_WDT_CTL_ICCSURV);
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if (mAllowExpectedReset == 0) {
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Readback |= B_PCH_OC_WDT_CTL_UNXP_RESET_STS;
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}
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DEBUG_CODE_BEGIN ();
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///
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/// In Debug mode, WDT will not be turned on. This is to prevent platform reboots triggered
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/// by WDT expiration, which can be expected when processor is halted for debugging
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///
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Readback &= ~(B_PCH_OC_WDT_CTL_EN | B_PCH_OC_WDT_CTL_FORCE_ALL | B_PCH_OC_WDT_CTL_UNXP_RESET_STS);
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DEBUG ((DEBUG_INFO, "(Wdt) Wdt disabled in Debug BIOS\n"));
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DEBUG_CODE_END ();
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Readback &= ~(B_PCH_OC_WDT_CTL_TOV_MASK);
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Readback |= ((TimeoutValue - 1) & B_PCH_OC_WDT_CTL_TOV_MASK);
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IoWrite32 (WdtGetAddress (), Readback);
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Readback |= B_PCH_OC_WDT_CTL_RLD;
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IoWrite32 (WdtGetAddress (), Readback);
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return EFI_SUCCESS;
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}
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/**
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Disables WDT timer.
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**/
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VOID
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EFIAPI
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WdtDisable (
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VOID
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)
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{
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UINT32 Readback;
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DEBUG ((DEBUG_INFO, "(Wdt) DisableTimer\n"));
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Readback = IoRead32 (WdtGetAddress ());
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Readback &= ~(B_PCH_OC_WDT_CTL_EN | B_PCH_OC_WDT_CTL_FORCE_ALL | B_PCH_OC_WDT_CTL_UNXP_RESET_STS);
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IoWrite32 (WdtGetAddress (), Readback);
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}
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/**
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Returns WDT failure status.
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@retval V_PCH_OC_WDT_CTL_STATUS_FAILURE If there was WDT expiration or unexpected reset
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@retval V_PCH_OC_WDT_CTL_STATUS_OK Otherwise
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**/
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UINT8
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EFIAPI
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WdtCheckStatus (
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VOID
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)
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{
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UINT32 Readback;
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DEBUG ((DEBUG_INFO, "(Wdt) CheckTimerStatus\n"));
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Readback = IoRead32 (WdtGetAddress ());
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DEBUG ((DEBUG_INFO, "(Wdt) Readback = (%x)\n", Readback));
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if (Readback & B_PCH_OC_WDT_CTL_FAILURE_STS) {
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DEBUG ((DEBUG_INFO, "(Wdt) Status = FAILURE\n"));
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return V_PCH_OC_WDT_CTL_STATUS_FAILURE;
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} else {
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return V_PCH_OC_WDT_CTL_STATUS_OK;
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}
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}
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/**
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Normally, each reboot performed while watchdog runs is considered a failure.
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This function allows platform to perform expected reboots with WDT running,
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without being interpreted as failures.
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In DXE phase, it is enough to call this function any time before reset.
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In PEI phase, between calling this function and performing reset, ReloadAndStart()
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must not be called.
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**/
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VOID
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EFIAPI
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WdtAllowKnownReset (
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VOID
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)
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{
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UINT32 Readback;
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DEBUG ((DEBUG_INFO, "(Wdt) AllowKnownReset\n"));
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mAllowExpectedReset = 1;
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Readback = IoRead32 (WdtGetAddress ());
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Readback &= ~(B_PCH_OC_WDT_CTL_UNXP_RESET_STS | B_PCH_OC_WDT_CTL_FORCE_ALL);
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IoWrite32 (WdtGetAddress (), Readback);
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}
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/**
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Returns information if WDT coverage for the duration of BIOS execution
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was requested by an OS application
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@retval TRUE if WDT was requested
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@retval FALSE if WDT was not requested
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**/
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UINT8
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EFIAPI
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IsWdtRequired (
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VOID
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)
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{
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UINT32 Readback;
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DEBUG ((DEBUG_INFO, "(Wdt) IsWdtRequired"));
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Readback = IoRead32 (WdtGetAddress ());
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if ((Readback & B_PCH_OC_WDT_CTL_AFTER_POST) != 0) {
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DEBUG ((DEBUG_INFO, " - yes\n"));
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return TRUE;
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} else {
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DEBUG ((DEBUG_INFO, " - no\n"));
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return FALSE;
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}
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}
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/**
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Returns WDT enabled/disabled status.
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@retval TRUE if WDT is enabled
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@retval FALSE if WDT is disabled
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**/
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UINT8
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EFIAPI
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IsWdtEnabled (
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VOID
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)
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{
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UINT32 Readback;
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DEBUG ((DEBUG_INFO, "(Wdt) IsWdtEnabled"));
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Readback = IoRead32 (WdtGetAddress ());
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if ((Readback & B_PCH_OC_WDT_CTL_EN) != 0) {
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DEBUG ((DEBUG_INFO, " - yes\n"));
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return TRUE;
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} else {
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DEBUG ((DEBUG_INFO, " - no\n"));
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return FALSE;
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}
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}
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