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   ASSERT_IRQL(SYNCH_LEVEL);
  50   KeAcquireSpinLockAtDpcLevel(SpinLock);
  51 }
  52
  53 #endif /* LIBCAPTIVE */
  54
  55 VOID STDCALL
  56 KeReleaseSpinLock (
  57         PKSPIN_LOCK     SpinLock,
  58         KIRQL           NewIrql
  59         )
  60 /*
  61  * FUNCTION: Releases a spinlock
  62  * ARGUMENTS:
  63  *        SpinLock = Spinlock to release
  64  *        NewIrql = Irql level before acquiring the spinlock
  65  */
  66 {
  67    KeReleaseSpinLockFromDpcLevel(SpinLock);
  68    KeLowerIrql(NewIrql);
  69 }
  70
  71 KIRQL FASTCALL
  72 KfAcquireSpinLock (
  73         PKSPIN_LOCK     SpinLock
  74         )
  75 {
  76    KIRQL OldIrql;
  77
  78    KeRaiseIrql(DISPATCH_LEVEL, &OldIrql);
  79    KeAcquireSpinLockAtDpcLevel(SpinLock);
  80
  81    return OldIrql;
  82 }
  83
  84 VOID 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 */