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/* $Id: spinlock-r0drv-freebsd.c $ */
/** @file
* IPRT - Spinlocks, Ring-0 Driver, FreeBSD.
*/
/*
* Copyright (c) 2007 knut st. osmundsen <bird-src-spam@anduin.net>
*
* 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 <iprt/spinlock.h>
#include <iprt/errcore.h>
#include <iprt/alloc.h>
#include <iprt/assert.h>
#include <iprt/asm.h>
#include <iprt/asm-amd64-x86.h>
#include <iprt/thread.h>
#include <iprt/mp.h>
#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();
}
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