/* $Id: spinlock-r0drv-freebsd.c $ */ /** @file * IPRT - Spinlocks, Ring-0 Driver, FreeBSD. */ /* * Contributed by knut st. osmundsen. * * Copyright (C) 2007-2023 Oracle and/or its affiliates. * * This file is part of VirtualBox base platform packages, as * available from https://www.virtualbox.org. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, in version 3 of the * License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included * in the VirtualBox 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. * * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 * -------------------------------------------------------------------- * * This code is based on: * * Copyright (c) 2007 knut st. osmundsen * * Permission is hereby granted, free of charge, to any person * obtaining a copy of this software and associated documentation * files (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, * copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following * conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include "the-freebsd-kernel.h" #include "internal/iprt.h" #include #include #include #include #include #include #include #include #include "internal/magics.h" /********************************************************************************************************************************* * Structures and Typedefs * *********************************************************************************************************************************/ /** * Wrapper for the struct mtx type. */ typedef struct RTSPINLOCKINTERNAL { /** Spinlock magic value (RTSPINLOCK_MAGIC). */ uint32_t volatile u32Magic; /** The spinlock. */ uint32_t volatile fLocked; /** Saved interrupt flag. */ uint32_t volatile fIntSaved; /** The spinlock creation flags. */ uint32_t fFlags; #ifdef RT_MORE_STRICT /** The idAssertCpu variable before acquring the lock for asserting after * releasing the spinlock. */ RTCPUID volatile idAssertCpu; /** The CPU that owns the lock. */ RTCPUID volatile idCpuOwner; #endif } RTSPINLOCKINTERNAL, *PRTSPINLOCKINTERNAL; RTDECL(int) RTSpinlockCreate(PRTSPINLOCK pSpinlock, uint32_t fFlags, const char *pszName) { RT_ASSERT_PREEMPTIBLE(); AssertReturn(fFlags == RTSPINLOCK_FLAGS_INTERRUPT_SAFE || fFlags == RTSPINLOCK_FLAGS_INTERRUPT_UNSAFE, VERR_INVALID_PARAMETER); /* * Allocate. */ AssertCompile(sizeof(RTSPINLOCKINTERNAL) > sizeof(void *)); PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)RTMemAllocZ(sizeof(*pThis)); if (!pThis) return VERR_NO_MEMORY; /* * Initialize & return. */ pThis->u32Magic = RTSPINLOCK_MAGIC; pThis->fLocked = 0; pThis->fFlags = fFlags; pThis->fIntSaved = 0; *pSpinlock = pThis; return VINF_SUCCESS; } RTDECL(int) RTSpinlockDestroy(RTSPINLOCK Spinlock) { /* * Validate input. */ RT_ASSERT_INTS_ON(); PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock; if (!pThis) return VERR_INVALID_PARAMETER; AssertMsgReturn(pThis->u32Magic == RTSPINLOCK_MAGIC, ("Invalid spinlock %p magic=%#x\n", pThis, pThis->u32Magic), VERR_INVALID_PARAMETER); /* * Make the lock invalid and release the memory. */ ASMAtomicIncU32(&pThis->u32Magic); RTMemFree(pThis); return VINF_SUCCESS; } RTDECL(void) RTSpinlockAcquire(RTSPINLOCK Spinlock) { PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock; RT_ASSERT_PREEMPT_CPUID_VAR(); AssertPtr(pThis); Assert(pThis->u32Magic == RTSPINLOCK_MAGIC); if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE) { for (;;) { uint32_t fIntSaved = ASMIntDisableFlags(); critical_enter(); int c = 50; for (;;) { if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0)) { RT_ASSERT_PREEMPT_CPUID_SPIN_ACQUIRED(pThis); pThis->fIntSaved = fIntSaved; return; } if (--c <= 0) break; cpu_spinwait(); } /* Enable interrupts while we sleep. */ ASMSetFlags(fIntSaved); critical_exit(); DELAY(1); } } else { for (;;) { critical_enter(); int c = 50; for (;;) { if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0)) { RT_ASSERT_PREEMPT_CPUID_SPIN_ACQUIRED(pThis); return; } if (--c <= 0) break; cpu_spinwait(); } critical_exit(); DELAY(1); } } } RTDECL(void) RTSpinlockRelease(RTSPINLOCK Spinlock) { PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock; RT_ASSERT_PREEMPT_CPUID_SPIN_RELEASE_VARS(); AssertPtr(pThis); Assert(pThis->u32Magic == RTSPINLOCK_MAGIC); RT_ASSERT_PREEMPT_CPUID_SPIN_RELEASE(pThis); if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE) { uint32_t fIntSaved = pThis->fIntSaved; pThis->fIntSaved = 0; if (ASMAtomicCmpXchgU32(&pThis->fLocked, 0, 1)) ASMSetFlags(fIntSaved); else AssertMsgFailed(("Spinlock %p was not locked!\n", pThis)); } else { if (!ASMAtomicCmpXchgU32(&pThis->fLocked, 0, 1)) AssertMsgFailed(("Spinlock %p was not locked!\n", pThis)); } critical_exit(); }