/* $Id: spinlock-r0drv-nt.cpp $ */ /** @file * IPRT - Spinlocks, Ring-0 Driver, NT. */ /* * Copyright (C) 2006-2019 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the * VirtualBox OSE distribution, in which case the provisions of the * CDDL are applicable instead of those of the GPL. * * You may elect to license modified versions of this file under the * terms and conditions of either the GPL or the CDDL or both. */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include "the-nt-kernel.h" #include <iprt/spinlock.h> #include <iprt/asm.h> #if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) # include <iprt/asm-amd64-x86.h> #endif #include <iprt/assert.h> #include <iprt/errcore.h> #include <iprt/mem.h> #include "internal/magics.h" /********************************************************************************************************************************* * Defined Constants And Macros * *********************************************************************************************************************************/ /** Apply the NoIrq hack if defined. */ #define RTSPINLOCK_NT_HACK_NOIRQ #ifdef RTSPINLOCK_NT_HACK_NOIRQ /** Indicates that the spinlock is taken. */ # define RTSPINLOCK_NT_HACK_NOIRQ_TAKEN UINT32(0x00c0ffee) /** Indicates that the spinlock is taken. */ # define RTSPINLOCK_NT_HACK_NOIRQ_FREE UINT32(0xfe0000fe) #endif /********************************************************************************************************************************* * Structures and Typedefs * *********************************************************************************************************************************/ /** * Wrapper for the KSPIN_LOCK type. */ typedef struct RTSPINLOCKINTERNAL { /** Spinlock magic value (RTSPINLOCK_MAGIC). */ uint32_t volatile u32Magic; #ifdef RTSPINLOCK_NT_HACK_NOIRQ /** Spinlock hack. */ uint32_t volatile u32Hack; #endif /** The saved IRQL. */ KIRQL volatile SavedIrql; /** The saved interrupt flag. */ RTCCUINTREG volatile fIntSaved; /** The spinlock creation flags. */ uint32_t fFlags; /** The NT spinlock structure. */ KSPIN_LOCK Spinlock; } RTSPINLOCKINTERNAL, *PRTSPINLOCKINTERNAL; RTDECL(int) RTSpinlockCreate(PRTSPINLOCK pSpinlock, uint32_t fFlags, const char *pszName) { AssertReturn(fFlags == RTSPINLOCK_FLAGS_INTERRUPT_SAFE || fFlags == RTSPINLOCK_FLAGS_INTERRUPT_UNSAFE, VERR_INVALID_PARAMETER); RT_NOREF1(pszName); /* * Allocate. */ Assert(sizeof(RTSPINLOCKINTERNAL) > sizeof(void *)); PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)RTMemAlloc(sizeof(*pThis)); if (!pThis) return VERR_NO_MEMORY; /* * Initialize & return. */ pThis->u32Magic = RTSPINLOCK_MAGIC; #ifdef RTSPINLOCK_NT_HACK_NOIRQ pThis->u32Hack = RTSPINLOCK_NT_HACK_NOIRQ_FREE; #endif pThis->SavedIrql = 0; pThis->fIntSaved = 0; pThis->fFlags = fFlags; KeInitializeSpinLock(&pThis->Spinlock); *pSpinlock = pThis; return VINF_SUCCESS; } RTDECL(int) RTSpinlockDestroy(RTSPINLOCK Spinlock) { /* * Validate input. */ PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock; if (!pThis) return VERR_INVALID_PARAMETER; if (pThis->u32Magic != RTSPINLOCK_MAGIC) { AssertMsgFailed(("Invalid spinlock %p magic=%#x\n", pThis, pThis->u32Magic)); return VERR_INVALID_PARAMETER; } ASMAtomicIncU32(&pThis->u32Magic); RTMemFree(pThis); return VINF_SUCCESS; } RTDECL(void) RTSpinlockAcquire(RTSPINLOCK Spinlock) { PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock; AssertMsg(pThis && pThis->u32Magic == RTSPINLOCK_MAGIC, ("magic=%#x\n", pThis->u32Magic)); KIRQL SavedIrql; if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE) { #ifndef RTSPINLOCK_NT_HACK_NOIRQ RTCCUINTREG fIntSaved = ASMGetFlags(); ASMIntDisable(); KeAcquireSpinLock(&pThis->Spinlock, &SavedIrql); #else SavedIrql = KeGetCurrentIrql(); if (SavedIrql < DISPATCH_LEVEL) { KeRaiseIrql(DISPATCH_LEVEL, &SavedIrql); Assert(SavedIrql < DISPATCH_LEVEL); } RTCCUINTREG fIntSaved = ASMGetFlags(); ASMIntDisable(); if (!ASMAtomicCmpXchgU32(&pThis->u32Hack, RTSPINLOCK_NT_HACK_NOIRQ_TAKEN, RTSPINLOCK_NT_HACK_NOIRQ_FREE)) { while (!ASMAtomicCmpXchgU32(&pThis->u32Hack, RTSPINLOCK_NT_HACK_NOIRQ_TAKEN, RTSPINLOCK_NT_HACK_NOIRQ_FREE)) ASMNopPause(); } #endif pThis->fIntSaved = fIntSaved; } else KeAcquireSpinLock(&pThis->Spinlock, &SavedIrql); pThis->SavedIrql = SavedIrql; } RTDECL(void) RTSpinlockRelease(RTSPINLOCK Spinlock) { PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock; AssertMsg(pThis && pThis->u32Magic == RTSPINLOCK_MAGIC, ("magic=%#x\n", pThis->u32Magic)); KIRQL SavedIrql = pThis->SavedIrql; if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE) { RTCCUINTREG fIntSaved = pThis->fIntSaved; pThis->fIntSaved = 0; #ifndef RTSPINLOCK_NT_HACK_NOIRQ KeReleaseSpinLock(&pThis->Spinlock, SavedIrql); ASMSetFlags(fIntSaved); #else Assert(pThis->u32Hack == RTSPINLOCK_NT_HACK_NOIRQ_TAKEN); ASMAtomicWriteU32(&pThis->u32Hack, RTSPINLOCK_NT_HACK_NOIRQ_FREE); ASMSetFlags(fIntSaved); if (SavedIrql < DISPATCH_LEVEL) KeLowerIrql(SavedIrql); #endif } else KeReleaseSpinLock(&pThis->Spinlock, SavedIrql); }