reactos/ntoskrnl/hal/x86/spinlock.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            kernel/hal/x86/spinlock.c
   5  * PURPOSE:         Implements spinlocks
   6  * PROGRAMMER:      David Welch (welch@mcmail.com)
   7  * UPDATE HISTORY:
   8  *                  3/6/98: Created
   9  */
  10
  11 /*
  12  * NOTE: On a uniprocessor machine spinlocks are implemented by raising
  13  * the irq level
  14  */
  15
  16 /* INCLUDES ****************************************************************/
  17
  18 #include <windows.h>
  19 #include <ddk/ntddk.h>
  20
  21 #include <internal/debug.h>
  22
  23 /* FUNCTIONS ***************************************************************/
  24
  25 BOOLEAN KeSynchronizeExecution(PKINTERRUPT Interrupt,
  26                                PKSYNCHRONIZE_ROUTINE SynchronizeRoutine,
  27                                PVOID SynchronizeContext)
  28 /*
  29  * FUNCTION: Synchronizes the execution of a given routine with the ISR
  30  * of a given interrupt object
  31  * ARGUMENTS:
  32  *       Interrupt = Interrupt object to synchronize with
  33  *       SynchronizeRoutine = Routine to call whose execution is
  34  *                            synchronized with the ISR
  35  *       SynchronizeContext = Parameter to pass to the synchronized routine
  36  * RETURNS: TRUE if the operation succeeded
  37  */
  38 {
  39    KIRQL oldlvl;
  40    BOOLEAN ret;
  41
  42    KeRaiseIrql(Interrupt->SynchLevel,&oldlvl);
  43    KeAcquireSpinLockAtDpcLevel(Interrupt->IrqLock);
  44
  45    ret = SynchronizeRoutine(SynchronizeContext);
  46
  47    KeReleaseSpinLockFromDpcLevel(Interrupt->IrqLock);
  48    KeLowerIrql(oldlvl);
  49
  50    return(ret);
  51 }
  52
  53 VOID KeInitializeSpinLock(PKSPIN_LOCK SpinLock)
  54 /*
  55  * FUNCTION: Initalizes a spinlock
  56  * ARGUMENTS:
  57  *           SpinLock = Caller supplied storage for the spinlock
  58  */
  59 {
  60    SpinLock->irql = DISPATCH_LEVEL;
  61 }
  62
  63 VOID KeAcquireSpinLockAtDpcLevel(PKSPIN_LOCK SpinLock)
  64 /*
  65  * FUNCTION: Acquires a spinlock when the caller is already running at
  66  * dispatch level
  67  * ARGUMENTS:
  68  *        SpinLock = Spinlock to acquire
  69  */
  70 {
  71 }
  72
  73 VOID KeReleaseSpinLockFromDpcLevel(PKSPIN_LOCK SpinLock)
  74 /*
  75  * FUNCTION: Releases a spinlock when the caller was running at dispatch
  76  * level before acquiring it
  77  * ARGUMENTS:
  78  *         SpinLock = Spinlock to release
  79  */
  80 {
  81 }
  82
  83 VOID KeAcquireSpinLock(PKSPIN_LOCK SpinLock, PKIRQL OldIrql)
  84 /*
  85  * FUNCTION: Acquires a spinlock
  86  * ARGUMENTS:
  87  *         SpinLock = Spinlock to acquire
  88  *         OldIrql (OUT) = Caller supplied storage for the previous irql
  89  */
  90 {
  91    KeRaiseIrql(DISPATCH_LEVEL,OldIrql);
  92 }
  93
  94 VOID KeReleaseSpinLock(PKSPIN_LOCK SpinLock, KIRQL NewIrql)
  95 /*
  96  * FUNCTION: Releases a spinlock
  97  * ARGUMENTS:
  98  *        SpinLock = Spinlock to release
  99  *        NewIrql = Irql level before acquiring the spinlock
 100  */
 101 {
 102    KeLowerIrql(NewIrql);
 103 }
 104