195 lines
4.1 KiB
C
195 lines
4.1 KiB
C
/*++
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Copyright (c) 1991, 1992, 1993 Microsoft Corporation
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Module Name:
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purge.c
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Abstract:
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This module contains the code that is very specific to purge
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operations in the serial driver
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Author:
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Anthony V. Ercolano 26-Sep-1991
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Environment:
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Kernel mode
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Revision History :
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--*/
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#include "precomp.h"
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text(PAGESER,SerialStartPurge)
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#pragma alloc_text(PAGESER,SerialPurgeInterruptBuff)
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#endif
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NTSTATUS
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SerialStartPurge(
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IN PSERIAL_DEVICE_EXTENSION Extension
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)
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/*++
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Routine Description:
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Depending on the mask in the current irp, purge the interrupt
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buffer, the read queue, or the write queue, or all of the above.
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Arguments:
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Extension - Pointer to the device extension.
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Return Value:
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Will return STATUS_SUCCESS always. This is reasonable
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since the DPC completion code that calls this routine doesn't
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care and the purge request always goes through to completion
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once it's started.
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--*/
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{
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PIRP NewIrp;
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SERIAL_LOCKED_PAGED_CODE();
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do {
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ULONG Mask;
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Mask = *((ULONG *)
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(Extension->CurrentPurgeIrp->AssociatedIrp.SystemBuffer));
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if (Mask & SERIAL_PURGE_TXABORT) {
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SerialKillAllReadsOrWrites(
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Extension->DeviceObject,
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&Extension->WriteQueue,
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&Extension->CurrentWriteIrp
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);
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SerialKillAllReadsOrWrites(
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Extension->DeviceObject,
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&Extension->WriteQueue,
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&Extension->CurrentXoffIrp
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);
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}
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if (Mask & SERIAL_PURGE_RXABORT) {
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SerialKillAllReadsOrWrites(
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Extension->DeviceObject,
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&Extension->ReadQueue,
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&Extension->CurrentReadIrp
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);
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}
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if (Mask & SERIAL_PURGE_RXCLEAR) {
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KIRQL OldIrql;
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//
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// Clean out the interrupt buffer.
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//
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// Note that we do this under protection of the
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// the drivers control lock so that we don't hose
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// the pointers if there is currently a read that
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// is reading out of the buffer.
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//
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KeAcquireSpinLock(
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&Extension->ControlLock,
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&OldIrql
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);
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KeSynchronizeExecution(
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Extension->Interrupt,
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SerialPurgeInterruptBuff,
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Extension
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);
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KeReleaseSpinLock(
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&Extension->ControlLock,
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OldIrql
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);
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}
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Extension->CurrentPurgeIrp->IoStatus.Status = STATUS_SUCCESS;
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Extension->CurrentPurgeIrp->IoStatus.Information = 0;
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SerialGetNextIrp(
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&Extension->CurrentPurgeIrp,
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&Extension->PurgeQueue,
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&NewIrp,
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TRUE,
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Extension
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);
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} while (NewIrp);
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return STATUS_SUCCESS;
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}
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BOOLEAN
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SerialPurgeInterruptBuff(
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IN PVOID Context
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)
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/*++
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Routine Description:
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This routine simply resets the interrupt (typeahead) buffer.
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NOTE: This routine is being called from KeSynchronizeExecution.
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Arguments:
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Context - Really a pointer to the device extension.
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Return Value:
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Always false.
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--*/
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{
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PSERIAL_DEVICE_EXTENSION Extension = Context;
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SERIAL_LOCKED_PAGED_CODE();
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//
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// The typeahead buffer is by definition empty if there
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// currently is a read owned by the isr.
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//
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if (Extension->ReadBufferBase == Extension->InterruptReadBuffer) {
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Extension->CurrentCharSlot = Extension->InterruptReadBuffer;
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Extension->FirstReadableChar = Extension->InterruptReadBuffer;
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Extension->LastCharSlot = Extension->InterruptReadBuffer +
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(Extension->BufferSize - 1);
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Extension->CharsInInterruptBuffer = 0;
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SerialHandleReducedIntBuffer(Extension);
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}
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return FALSE;
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}
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