hal/halx86/spinlock.c

   1 /* $Id$
   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   ASSERT_IRQL(SYNCH_LEVEL);
  48   KeAcquireSpinLockAtDpcLevel(SpinLock);
  49 }
  50
  51 VOID STDCALL
  52 KeReleaseSpinLock (
  53         PKSPIN_LOCK     SpinLock,
  54         KIRQL           NewIrql
  55         )
  56 /*
  57  * FUNCTION: Releases a spinlock
  58  * ARGUMENTS:
  59  *        SpinLock = Spinlock to release
  60  *        NewIrql = Irql level before acquiring the spinlock
  61  */
  62 {
  63    KeReleaseSpinLockFromDpcLevel(SpinLock);
  64    KeLowerIrql(NewIrql);
  65 }
  66
  67 KIRQL FASTCALL
  68 KfAcquireSpinLock (
  69         PKSPIN_LOCK     SpinLock
  70         )
  71 {
  72    KIRQL OldIrql;
  73
  74    KeRaiseIrql(DISPATCH_LEVEL, &OldIrql);
  75    KeAcquireSpinLockAtDpcLevel(SpinLock);
  76
  77    return OldIrql;
  78 }
  79
  80 VOID FASTCALL
  81 KfReleaseSpinLock (
  82         PKSPIN_LOCK     SpinLock,
  83         KIRQL           NewIrql
  84         )
  85 /*
  86  * FUNCTION: Releases a spinlock
  87  * ARGUMENTS:
  88  *        SpinLock = Spinlock to release
  89  *        NewIrql = Irql level before acquiring the spinlock
  90  */
  91 {
  92    KeReleaseSpinLockFromDpcLevel(SpinLock);
  93    KeLowerIrql(NewIrql);
  94 }
  95
  96 /* EOF */