115 lines
2.4 KiB
C++
115 lines
2.4 KiB
C++
/**
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* PROJECT: ExectOS
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* COPYRIGHT: See COPYING.md in the top level directory
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* FILE: xtoskrnl/ke/spinlock.cc
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* DESCRIPTION: Spinlocks support
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* DEVELOPERS: Rafal Kupiec <belliash@codingworkshop.eu.org>
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*/
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#include <xtos.hh>
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/**
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* Acquires a specified queued spinlock.
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*
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* @param LockLevel
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* Supplies the queued spinlock level.
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*
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* @return This routine does not return any value.
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*
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* @since XT 1.0
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*/
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XTFASTCALL
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VOID
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KE::SpinLock::AcquireQueuedSpinLock(IN KSPIN_LOCK_QUEUE_LEVEL LockLevel)
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{
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/* Acquire the queued spinlock */
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AcquireSpinLock(KE::Processor::GetCurrentProcessorControlBlock()->LockQueue[LockLevel].Lock);
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}
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/**
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* Acquires a kernel spin lock.
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*
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* @param SpinLock
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* Supplies a pointer to the kernel spin lock.
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*
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* @return This routine does not return any value.
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*
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* @since XT 1.0
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*/
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XTFASTCALL
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VOID
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KE::SpinLock::AcquireSpinLock(IN OUT PKSPIN_LOCK SpinLock)
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{
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/* Try to acquire the lock */
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while(RTL::Atomic::BitTestAndSet((PLONG)SpinLock, 0))
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{
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/* Wait until locked is cleared */
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while(*(VOLATILE PKSPIN_LOCK)SpinLock & 1)
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{
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/* Yield processor and keep waiting */
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AR::CpuFunc::YieldProcessor();
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}
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}
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/* Add an explicit memory barrier */
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AR::CpuFunc::ReadWriteBarrier();
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}
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/**
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* Initializes a kernel spinlock object.
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*
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* @param SpinLock
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* Supplies a pointer to a kernel spin lock.
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*
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* @return This routine does not return any value.
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*
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* @since NT 3.5
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*/
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XTAPI
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VOID
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KE::SpinLock::InitializeSpinLock(IN PKSPIN_LOCK SpinLock)
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{
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/* Zero initialize spinlock */
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*SpinLock = 0;
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}
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/**
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* Releases a queued spinlock.
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*
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* @param LockLevel
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* Supplies the queued spinlock level.
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*
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* @return This routine does not return any value.
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*
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* @since XT 1.0
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*/
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XTFASTCALL
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VOID
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KE::SpinLock::ReleaseQueuedSpinLock(IN KSPIN_LOCK_QUEUE_LEVEL LockLevel)
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{
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/* Clear the lock */
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ReleaseSpinLock(KE::Processor::GetCurrentProcessorControlBlock()->LockQueue[LockLevel].Lock);
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}
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/**
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* Releases a kernel spin lock.
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*
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* @param SpinLock
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* Supplies a pointer to the kernel spin lock.
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*
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* @return This routine does not return any value.
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*
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* @since XT 1.0
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*/
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XTFASTCALL
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VOID
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KE::SpinLock::ReleaseSpinLock(IN OUT PKSPIN_LOCK SpinLock)
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{
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/* Clear the lock */
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RTL::Atomic::And32((PLONG)SpinLock, 0);
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/* Add an explicit memory barrier */
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AR::CpuFunc::ReadWriteBarrier();
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}
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