reactos/ntoskrnl/hal/x86/spinlock.c

   1 /* $Id: spinlock.c,v 1.11 2000/06/09 22:22:32 ea 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
  27 STDCALL
  28 KeAcquireSpinLock (
  29         PKSPIN_LOCK     SpinLock,
  30         PKIRQL          OldIrql
  31         )
  32 /*
  33  * FUNCTION: Acquires a spinlock
  34  * ARGUMENTS:
  35  *         SpinLock = Spinlock to acquire
  36  *         OldIrql (OUT) = Caller supplied storage for the previous irql
  37  */
  38 {
  39    KeRaiseIrql(DISPATCH_LEVEL,OldIrql);
  40    KeAcquireSpinLockAtDpcLevel(SpinLock);
  41 }
  42
  43 KIRQL
  44 FASTCALL
  45 KeAcquireSpinLockRaiseToSynch (
  46         PKSPIN_LOCK     SpinLock
  47         )
  48 {
  49    UNIMPLEMENTED;
  50 }
  51
  52 VOID
  53 STDCALL
  54 KeReleaseSpinLock (
  55         PKSPIN_LOCK     SpinLock,
  56         KIRQL           NewIrql
  57         )
  58 /*
  59  * FUNCTION: Releases a spinlock
  60  * ARGUMENTS:
  61  *        SpinLock = Spinlock to release
  62  *        NewIrql = Irql level before acquiring the spinlock
  63  */
  64 {
  65    KeReleaseSpinLockFromDpcLevel(SpinLock);
  66    KeLowerIrql(NewIrql);
  67 }
  68
  69 KIRQL
  70 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
  84 FASTCALL
  85 KfReleaseSpinLock (
  86         PKSPIN_LOCK     SpinLock,
  87         KIRQL           NewIrql
  88         )
  89 /*
  90  * FUNCTION: Releases a spinlock
  91  * ARGUMENTS:
  92  *        SpinLock = Spinlock to release
  93  *        NewIrql = Irql level before acquiring the spinlock
  94  */
  95 {
  96    KeReleaseSpinLockFromDpcLevel(SpinLock);
  97    KeLowerIrql(NewIrql);
  98 }
  99
 100 /* EOF */