diff options
Diffstat (limited to 'src/VBox/Runtime/r0drv/darwin/threadpreempt-r0drv-darwin.cpp')
| -rw-r--r-- | src/VBox/Runtime/r0drv/darwin/threadpreempt-r0drv-darwin.cpp | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r0drv/darwin/threadpreempt-r0drv-darwin.cpp b/src/VBox/Runtime/r0drv/darwin/threadpreempt-r0drv-darwin.cpp new file mode 100644 index 00000000..0358e7de --- /dev/null +++ b/src/VBox/Runtime/r0drv/darwin/threadpreempt-r0drv-darwin.cpp @@ -0,0 +1,203 @@ +/* $Id: threadpreempt-r0drv-darwin.cpp $ */ +/** @file + * IPRT - Thread Preemption, Ring-0 Driver, Darwin. + */ + +/* + * Copyright (C) 2009-2020 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-darwin-kernel.h" +#include "internal/iprt.h" +#include <iprt/thread.h> + +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) +# include <iprt/asm-amd64-x86.h> +#endif +#include <iprt/assert.h> +#include <iprt/cpuset.h> +#include <iprt/errcore.h> +#include <iprt/mp.h> + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +typedef struct RTDARWINPREEMPTHACK +{ + /** The spinlock we exploit for disabling preemption. */ + lck_spin_t *pSpinLock; + /** The preemption count for this CPU, to guard against nested calls. */ + uint32_t cRecursion; +} RTDARWINPREEMPTHACK; +typedef RTDARWINPREEMPTHACK *PRTDARWINPREEMPTHACK; + + +/********************************************************************************************************************************* +* Global Variables * +*********************************************************************************************************************************/ +static RTDARWINPREEMPTHACK g_aPreemptHacks[RTCPUSET_MAX_CPUS]; + + +/** + * Allocates the per-cpu spin locks used to disable preemption. + * + * Called by rtR0InitNative. + */ +int rtThreadPreemptDarwinInit(void) +{ + Assert(g_pDarwinLockGroup); + IPRT_DARWIN_SAVE_EFL_AC(); + + for (size_t i = 0; i < RT_ELEMENTS(g_aPreemptHacks); i++) + { + g_aPreemptHacks[i].pSpinLock = lck_spin_alloc_init(g_pDarwinLockGroup, LCK_ATTR_NULL); + if (!g_aPreemptHacks[i].pSpinLock) + return VERR_NO_MEMORY; /* (The caller will invoke rtThreadPreemptDarwinTerm) */ + } + IPRT_DARWIN_RESTORE_EFL_AC(); + return VINF_SUCCESS; +} + + +/** + * Frees the per-cpu spin locks used to disable preemption. + * + * Called by rtR0TermNative. + */ +void rtThreadPreemptDarwinTerm(void) +{ + IPRT_DARWIN_SAVE_EFL_AC(); + + for (size_t i = 0; i < RT_ELEMENTS(g_aPreemptHacks); i++) + if (g_aPreemptHacks[i].pSpinLock) + { + lck_spin_free(g_aPreemptHacks[i].pSpinLock, g_pDarwinLockGroup); + g_aPreemptHacks[i].pSpinLock = NULL; + } + + IPRT_DARWIN_RESTORE_EFL_AC(); +} + + +RTDECL(bool) RTThreadPreemptIsEnabled(RTTHREAD hThread) +{ + RT_NOREF(hThread); + Assert(hThread == NIL_RTTHREAD); + return preemption_enabled(); +} + + +RTDECL(bool) RTThreadPreemptIsPending(RTTHREAD hThread) +{ + RT_NOREF(hThread); + if (!g_pfnR0DarwinAstPending) + return false; + uint32_t volatile *pfAstPending = g_pfnR0DarwinAstPending(); AssertPtr(pfAstPending); + uint32_t const fAstPending = *pfAstPending; + + AssertMsg(!(fAstPending & UINT32_C(0xfffe0000)), ("%#x\n", fAstPending)); + return (fAstPending & (AST_PREEMPT | AST_QUANTUM | AST_URGENT)) != 0; +} + + +RTDECL(bool) RTThreadPreemptIsPendingTrusty(void) +{ + /* yes, we think that RTThreadPreemptIsPending is reliable... */ + return g_pfnR0DarwinAstPending != NULL; +} + + +RTDECL(bool) RTThreadPreemptIsPossible(void) +{ + /* yes, kernel preemption is possible. */ + return true; +} + + +RTDECL(void) RTThreadPreemptDisable(PRTTHREADPREEMPTSTATE pState) +{ + AssertPtr(pState); + Assert(pState->u32Reserved == 0); + pState->u32Reserved = 42; + + /* + * Disable to prevent preemption while we grab the per-cpu spin lock. + * Note! Only take the lock on the first call or we end up spinning for ever. + */ + RTCCUINTREG fSavedFlags = ASMIntDisableFlags(); + RTCPUID idCpu = RTMpCpuId(); + if (RT_UNLIKELY(idCpu < RT_ELEMENTS(g_aPreemptHacks))) + { + Assert(g_aPreemptHacks[idCpu].cRecursion < UINT32_MAX / 2); + if (++g_aPreemptHacks[idCpu].cRecursion == 1) + { + lck_spin_t *pSpinLock = g_aPreemptHacks[idCpu].pSpinLock; + if (pSpinLock) + lck_spin_lock(pSpinLock); + else + AssertFailed(); + } + } + ASMSetFlags(fSavedFlags); + Assert(!RTThreadPreemptIsEnabled(NIL_RTTHREAD)); + RT_ASSERT_PREEMPT_CPUID_DISABLE(pState); +} + + +RTDECL(void) RTThreadPreemptRestore(PRTTHREADPREEMPTSTATE pState) +{ + AssertPtr(pState); + Assert(pState->u32Reserved == 42); + pState->u32Reserved = 0; + RT_ASSERT_PREEMPT_CPUID_RESTORE(pState); + + RTCPUID idCpu = RTMpCpuId(); + if (RT_UNLIKELY(idCpu < RT_ELEMENTS(g_aPreemptHacks))) + { + Assert(g_aPreemptHacks[idCpu].cRecursion > 0); + if (--g_aPreemptHacks[idCpu].cRecursion == 0) + { + lck_spin_t *pSpinLock = g_aPreemptHacks[idCpu].pSpinLock; + if (pSpinLock) + { + IPRT_DARWIN_SAVE_EFL_AC(); + lck_spin_unlock(pSpinLock); + IPRT_DARWIN_RESTORE_EFL_AC(); + } + else + AssertFailed(); + } + } +} + + +RTDECL(bool) RTThreadIsInInterrupt(RTTHREAD hThread) +{ + Assert(hThread == NIL_RTTHREAD); NOREF(hThread); + /** @todo Darwin: Implement RTThreadIsInInterrupt. Required for guest + * additions! */ + return !ASMIntAreEnabled(); +} + |