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 #ifndef LIBCAPTIVE
  43
  44 KIRQL FASTCALL
  45 KeAcquireSpinLockRaiseToSynch (
  46         PKSPIN_LOCK     SpinLock
  47         )
  48 {
  49    UNIMPLEMENTED;
  50 }
  51
  52 #endif /* LIBCAPTIVE */
  53
  54 VOID STDCALL
  55 KeReleaseSpinLock (
  56         PKSPIN_LOCK     SpinLock,
  57         KIRQL           NewIrql
  58         )
  59 /*
  60  * FUNCTION: Releases a spinlock
  61  * ARGUMENTS:
  62  *        SpinLock = Spinlock to release
  63  *        NewIrql = Irql level before acquiring the spinlock
  64  */
  65 {
  66    KeReleaseSpinLockFromDpcLevel(SpinLock);
  67    KeLowerIrql(NewIrql);
  68 }
  69
  70 KIRQL FASTCALL
  71 KfAcquireSpinLock (
  72         PKSPIN_LOCK     SpinLock
  73         )
  74 {
  75    KIRQL OldIrql;
  76
  77    KeRaiseIrql(DISPATCH_LEVEL, &OldIrql);
  78    KeAcquireSpinLockAtDpcLevel(SpinLock);
  79
  80    return OldIrql;
  81 }
  82
  83 VOID FASTCALL
  84 KfReleaseSpinLock (
  85         PKSPIN_LOCK     SpinLock,
  86         KIRQL           NewIrql
  87         )
  88 /*
  89  * FUNCTION: Releases a spinlock
  90  * ARGUMENTS:
  91  *        SpinLock = Spinlock to release
  92  *        NewIrql = Irql level before acquiring the spinlock
  93  */
  94 {
  95    KeReleaseSpinLockFromDpcLevel(SpinLock);
  96    KeLowerIrql(NewIrql);
  97 }
  98
  99 /* EOF */