| 1 | /* $Id: spinlock-r0drv-linux.c 106061 2024-09-16 14:03:52Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * IPRT - Spinlocks, Ring-0 Driver, Linux.
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2006-2024 Oracle and/or its affiliates.
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox base platform packages, as
|
|---|
| 10 | * available from https://www.virtualbox.org.
|
|---|
| 11 | *
|
|---|
| 12 | * This program is free software; you can redistribute it and/or
|
|---|
| 13 | * modify it under the terms of the GNU General Public License
|
|---|
| 14 | * as published by the Free Software Foundation, in version 3 of the
|
|---|
| 15 | * License.
|
|---|
| 16 | *
|
|---|
| 17 | * This program is distributed in the hope that it will be useful, but
|
|---|
| 18 | * WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|---|
| 20 | * General Public License for more details.
|
|---|
| 21 | *
|
|---|
| 22 | * You should have received a copy of the GNU General Public License
|
|---|
| 23 | * along with this program; if not, see <https://www.gnu.org/licenses>.
|
|---|
| 24 | *
|
|---|
| 25 | * The contents of this file may alternatively be used under the terms
|
|---|
| 26 | * of the Common Development and Distribution License Version 1.0
|
|---|
| 27 | * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
|
|---|
| 28 | * in the VirtualBox distribution, in which case the provisions of the
|
|---|
| 29 | * CDDL are applicable instead of those of the GPL.
|
|---|
| 30 | *
|
|---|
| 31 | * You may elect to license modified versions of this file under the
|
|---|
| 32 | * terms and conditions of either the GPL or the CDDL or both.
|
|---|
| 33 | *
|
|---|
| 34 | * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
|
|---|
| 35 | */
|
|---|
| 36 |
|
|---|
| 37 |
|
|---|
| 38 | /*********************************************************************************************************************************
|
|---|
| 39 | * Header Files *
|
|---|
| 40 | *********************************************************************************************************************************/
|
|---|
| 41 | #include "the-linux-kernel.h"
|
|---|
| 42 | #include "internal/iprt.h"
|
|---|
| 43 | #include <iprt/spinlock.h>
|
|---|
| 44 |
|
|---|
| 45 | #include <iprt/asm.h>
|
|---|
| 46 | #if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
|
|---|
| 47 | # include <iprt/asm-amd64-x86.h>
|
|---|
| 48 | #endif
|
|---|
| 49 | #include <iprt/assert.h>
|
|---|
| 50 | #include <iprt/errcore.h>
|
|---|
| 51 | #include <iprt/mem.h>
|
|---|
| 52 | #include <iprt/mp.h>
|
|---|
| 53 | #include <iprt/thread.h>
|
|---|
| 54 | #include "internal/magics.h"
|
|---|
| 55 |
|
|---|
| 56 |
|
|---|
| 57 | /*********************************************************************************************************************************
|
|---|
| 58 | * Structures and Typedefs *
|
|---|
| 59 | *********************************************************************************************************************************/
|
|---|
| 60 | /**
|
|---|
| 61 | * Wrapper for the spinlock_t structure.
|
|---|
| 62 | */
|
|---|
| 63 | typedef struct RTSPINLOCKINTERNAL
|
|---|
| 64 | {
|
|---|
| 65 | /** Spinlock magic value (RTSPINLOCK_MAGIC). */
|
|---|
| 66 | uint32_t volatile u32Magic;
|
|---|
| 67 | /** The spinlock creation flags. */
|
|---|
| 68 | uint32_t fFlags;
|
|---|
| 69 | /** The saved interrupt flag. */
|
|---|
| 70 | unsigned long volatile fIntSaved;
|
|---|
| 71 | /** The linux spinlock structure. */
|
|---|
| 72 | spinlock_t Spinlock;
|
|---|
| 73 | #ifdef RT_MORE_STRICT
|
|---|
| 74 | /** The idAssertCpu variable before acquring the lock for asserting after
|
|---|
| 75 | * releasing the spinlock. */
|
|---|
| 76 | RTCPUID volatile idAssertCpu;
|
|---|
| 77 | /** The CPU that owns the lock. */
|
|---|
| 78 | RTCPUID volatile idCpuOwner;
|
|---|
| 79 | #endif
|
|---|
| 80 | } RTSPINLOCKINTERNAL, *PRTSPINLOCKINTERNAL;
|
|---|
| 81 |
|
|---|
| 82 |
|
|---|
| 83 |
|
|---|
| 84 | RTDECL(int) RTSpinlockCreate(PRTSPINLOCK pSpinlock, uint32_t fFlags, const char *pszName)
|
|---|
| 85 | {
|
|---|
| 86 | IPRT_LINUX_SAVE_EFL_AC();
|
|---|
| 87 | PRTSPINLOCKINTERNAL pThis;
|
|---|
| 88 | AssertReturn(fFlags == RTSPINLOCK_FLAGS_INTERRUPT_SAFE || fFlags == RTSPINLOCK_FLAGS_INTERRUPT_UNSAFE, VERR_INVALID_PARAMETER);
|
|---|
| 89 | RT_NOREF_PV(pszName);
|
|---|
| 90 |
|
|---|
| 91 | /*
|
|---|
| 92 | * Allocate.
|
|---|
| 93 | */
|
|---|
| 94 | Assert(sizeof(RTSPINLOCKINTERNAL) > sizeof(void *));
|
|---|
| 95 | pThis = (PRTSPINLOCKINTERNAL)RTMemAlloc(sizeof(*pThis));
|
|---|
| 96 | if (!pThis)
|
|---|
| 97 | return VERR_NO_MEMORY;
|
|---|
| 98 | /*
|
|---|
| 99 | * Initialize and return.
|
|---|
| 100 | */
|
|---|
| 101 | pThis->u32Magic = RTSPINLOCK_MAGIC;
|
|---|
| 102 | pThis->fFlags = fFlags;
|
|---|
| 103 | pThis->fIntSaved = 0;
|
|---|
| 104 | #ifdef RT_MORE_STRICT
|
|---|
| 105 | pThis->idCpuOwner = NIL_RTCPUID;
|
|---|
| 106 | pThis->idAssertCpu = NIL_RTCPUID;
|
|---|
| 107 | #endif
|
|---|
| 108 |
|
|---|
| 109 | spin_lock_init(&pThis->Spinlock);
|
|---|
| 110 |
|
|---|
| 111 | *pSpinlock = pThis;
|
|---|
| 112 | IPRT_LINUX_RESTORE_EFL_AC();
|
|---|
| 113 | return VINF_SUCCESS;
|
|---|
| 114 | }
|
|---|
| 115 | RT_EXPORT_SYMBOL(RTSpinlockCreate);
|
|---|
| 116 |
|
|---|
| 117 |
|
|---|
| 118 | RTDECL(int) RTSpinlockDestroy(RTSPINLOCK Spinlock)
|
|---|
| 119 | {
|
|---|
| 120 | /*
|
|---|
| 121 | * Validate input.
|
|---|
| 122 | */
|
|---|
| 123 | PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
|
|---|
| 124 | if (!pThis)
|
|---|
| 125 | return VERR_INVALID_PARAMETER;
|
|---|
| 126 | if (pThis->u32Magic != RTSPINLOCK_MAGIC)
|
|---|
| 127 | {
|
|---|
| 128 | AssertMsgFailed(("Invalid spinlock %p magic=%#x\n", pThis, pThis->u32Magic));
|
|---|
| 129 | return VERR_INVALID_PARAMETER;
|
|---|
| 130 | }
|
|---|
| 131 |
|
|---|
| 132 | ASMAtomicIncU32(&pThis->u32Magic);
|
|---|
| 133 | RTMemFree(pThis);
|
|---|
| 134 | return VINF_SUCCESS;
|
|---|
| 135 | }
|
|---|
| 136 | RT_EXPORT_SYMBOL(RTSpinlockDestroy);
|
|---|
| 137 |
|
|---|
| 138 |
|
|---|
| 139 | RTDECL(void) RTSpinlockAcquire(RTSPINLOCK Spinlock)
|
|---|
| 140 | {
|
|---|
| 141 | PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
|
|---|
| 142 | IPRT_LINUX_SAVE_EFL_AC();
|
|---|
| 143 | RT_ASSERT_PREEMPT_CPUID_VAR();
|
|---|
| 144 | AssertMsg(pThis && pThis->u32Magic == RTSPINLOCK_MAGIC,
|
|---|
| 145 | ("pThis=%p u32Magic=%08x\n", pThis, pThis ? (int)pThis->u32Magic : 0));
|
|---|
| 146 |
|
|---|
| 147 | #ifdef CONFIG_PROVE_LOCKING
|
|---|
| 148 | lockdep_off();
|
|---|
| 149 | #endif
|
|---|
| 150 | if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE)
|
|---|
| 151 | {
|
|---|
| 152 | unsigned long fIntSaved;
|
|---|
| 153 | spin_lock_irqsave(&pThis->Spinlock, fIntSaved);
|
|---|
| 154 | pThis->fIntSaved = fIntSaved;
|
|---|
| 155 | }
|
|---|
| 156 | else
|
|---|
| 157 | spin_lock(&pThis->Spinlock);
|
|---|
| 158 | #ifdef CONFIG_PROVE_LOCKING
|
|---|
| 159 | lockdep_on();
|
|---|
| 160 | #endif
|
|---|
| 161 |
|
|---|
| 162 | IPRT_LINUX_RESTORE_EFL_ONLY_AC();
|
|---|
| 163 | RT_ASSERT_PREEMPT_CPUID_SPIN_ACQUIRED(pThis);
|
|---|
| 164 | }
|
|---|
| 165 | RT_EXPORT_SYMBOL(RTSpinlockAcquire);
|
|---|
| 166 |
|
|---|
| 167 |
|
|---|
| 168 | RTDECL(void) RTSpinlockRelease(RTSPINLOCK Spinlock)
|
|---|
| 169 | {
|
|---|
| 170 | PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
|
|---|
| 171 | IPRT_LINUX_SAVE_EFL_AC(); /* spin_unlock* may preempt and trash eflags.ac. */
|
|---|
| 172 | RT_ASSERT_PREEMPT_CPUID_SPIN_RELEASE_VARS();
|
|---|
| 173 | AssertMsg(pThis && pThis->u32Magic == RTSPINLOCK_MAGIC,
|
|---|
| 174 | ("pThis=%p u32Magic=%08x\n", pThis, pThis ? (int)pThis->u32Magic : 0));
|
|---|
| 175 | RT_ASSERT_PREEMPT_CPUID_SPIN_RELEASE(pThis);
|
|---|
| 176 |
|
|---|
| 177 | #ifdef CONFIG_PROVE_LOCKING
|
|---|
| 178 | lockdep_off();
|
|---|
| 179 | #endif
|
|---|
| 180 | if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE)
|
|---|
| 181 | {
|
|---|
| 182 | unsigned long fIntSaved = pThis->fIntSaved;
|
|---|
| 183 | pThis->fIntSaved = 0;
|
|---|
| 184 | spin_unlock_irqrestore(&pThis->Spinlock, fIntSaved);
|
|---|
| 185 | }
|
|---|
| 186 | else
|
|---|
| 187 | spin_unlock(&pThis->Spinlock);
|
|---|
| 188 | #ifdef CONFIG_PROVE_LOCKING
|
|---|
| 189 | lockdep_on();
|
|---|
| 190 | #endif
|
|---|
| 191 |
|
|---|
| 192 | IPRT_LINUX_RESTORE_EFL_ONLY_AC();
|
|---|
| 193 | RT_ASSERT_PREEMPT_CPUID();
|
|---|
| 194 | }
|
|---|
| 195 | RT_EXPORT_SYMBOL(RTSpinlockRelease);
|
|---|
| 196 |
|
|---|
