reactos/hal/halx86/spinlock.c

   1 /* $Id: spinlock.c,v 1.3 2002/09/08 10:22:24 chorns Exp $
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/hal/x86/spinlock.c
   6  * PURPOSE:         Implements spinlocks
   7  * PROGRAMMER:      David Welch (welch@cwcom.net)
   8  *                  Eric Kohl (ekohl@rz-online.de)
   9  * UPDATE HISTORY:
  10  *                  09/06/2000 Created
  11  */
  12
  13 /*
  14  * NOTE: On a uniprocessor machine spinlocks are implemented by raising
  15  * the irq level
  16  */
  17
  18 /* INCLUDES ****************************************************************/
  19
  20 #include <ddk/ntddk.h>
  21
  22 #include <internal/debug.h>
  23
  24 /* FUNCTIONS ***************************************************************/
  25
  26 VOID STDCALL
  27 KeAcquireSpinLock (
  28         PKSPIN_LOCK     SpinLock,
  29         PKIRQL          OldIrql
  30         )
  31 /*
  32  * FUNCTION: Acquires a spinlock
  33  * ARGUMENTS:
  34  *         SpinLock = Spinlock to acquire
  35  *         OldIrql (OUT) = Caller supplied storage for the previous irql
  36  */
  37 {
  38    KeRaiseIrql(DISPATCH_LEVEL,OldIrql);
  39    KeAcquireSpinLockAtDpcLevel(SpinLock);
  40 }
  41
  42 KIRQL FASTCALL
  43 KeAcquireSpinLockRaiseToSynch (
  44         PKSPIN_LOCK     SpinLock
  45         )
  46 {
  47    UNIMPLEMENTED;
  48 }
  49
  50 VOID STDCALL
  51 KeReleaseSpinLock (
  52         PKSPIN_LOCK     SpinLock,
  53         KIRQL           NewIrql
  54         )
  55 /*
  56  * FUNCTION: Releases a spinlock
  57  * ARGUMENTS:
  58  *        SpinLock = Spinlock to release
  59  *        NewIrql = Irql level before acquiring the spinlock
  60  */
  61 {
  62    KeReleaseSpinLockFromDpcLevel(SpinLock);
  63    KeLowerIrql(NewIrql);
  64 }
  65
  66 KIRQL FASTCALL
  67 KfAcquireSpinLock (
  68         PKSPIN_LOCK     SpinLock
  69         )
  70 {
  71    KIRQL OldIrql;
  72
  73    KeRaiseIrql(DISPATCH_LEVEL, &OldIrql);
  74    KeAcquireSpinLockAtDpcLevel(SpinLock);
  75
  76    return OldIrql;
  77 }
  78
  79 VOID FASTCALL
  80 KfReleaseSpinLock (
  81         PKSPIN_LOCK     SpinLock,
  82         KIRQL           NewIrql
  83         )
  84 /*
  85  * FUNCTION: Releases a spinlock
  86  * ARGUMENTS:
  87  *        SpinLock = Spinlock to release
  88  *        NewIrql = Irql level before acquiring the spinlock
  89  */
  90 {
  91    KeReleaseSpinLockFromDpcLevel(SpinLock);
  92    KeLowerIrql(NewIrql);
  93 }
  94
  95 /* EOF */