// this procedure must be called with port InBuf spinlock held
SSIZE_T
VIOSerialFillReadBufLocked(
IN PVIOSERIAL_PORT port,
IN PVOID outbuf,
IN SIZE_T count
)
{
PPORT_BUFFER buf;
NTSTATUS status = STATUS_SUCCESS;
TraceEvents(TRACE_LEVEL_VERBOSE, DBG_QUEUEING, "--> %s\n", __FUNCTION__);
if (!count || !VIOSerialPortHasDataLocked(port))
return 0;
buf = port->InBuf;
count = min(count, buf->len - buf->offset);
RtlCopyMemory(outbuf, (PVOID)((LONG_PTR)buf->va_buf + buf->offset), count);
buf->offset += count;
if (buf->offset == buf->len)
{
port->InBuf = NULL;
status = VIOSerialAddInBuf(GetInQueue(port), buf);
if (!NT_SUCCESS(status))
{
TraceEvents(TRACE_LEVEL_ERROR, DBG_QUEUEING, "%s::%d VIOSerialAddInBuf failed\n", __FUNCTION__, __LINE__);
}
}
TraceEvents(TRACE_LEVEL_VERBOSE, DBG_QUEUEING, "<-- %s\n", __FUNCTION__);
return count;
}
VOID
VIOSerialPortRead(
IN WDFQUEUE Queue,
IN WDFREQUEST Request,
IN size_t Length
)
{
PRAWPDO_VIOSERIAL_PORT pdoData = RawPdoSerialPortGetData(WdfIoQueueGetDevice(Queue));
size_t length;
NTSTATUS status;
PVOID systemBuffer;
BOOLEAN nonBlock;
TraceEvents(TRACE_LEVEL_INFORMATION, DBG_READ, "-->%s\n", __FUNCTION__);
nonBlock = ((WdfFileObjectGetFlags(WdfRequestGetFileObject(Request)) & FO_SYNCHRONOUS_IO) != FO_SYNCHRONOUS_IO);
status = WdfRequestRetrieveOutputBuffer(Request, Length, &systemBuffer, &length);
if (!NT_SUCCESS(status))
{
WdfRequestComplete(Request, status);
return;
}
WdfSpinLockAcquire(pdoData->port->InBufLock);
if (!VIOSerialPortHasDataLocked(pdoData->port))
{
if (!pdoData->port->HostConnected)
{
WdfRequestComplete(Request, STATUS_INSUFFICIENT_RESOURCES);
}
else
{
ASSERT (pdoData->port->PendingReadRequest == NULL);
status = WdfRequestMarkCancelableEx(Request,
VIOSerialPortReadRequestCancel);
if (!NT_SUCCESS(status))
{
WdfRequestComplete(Request, status);
}
else
{
pdoData->port->PendingReadRequest = Request;
}
}
}
else
{
length = (ULONG)VIOSerialFillReadBufLocked(pdoData->port, systemBuffer, length);
if (length)
{
WdfRequestCompleteWithInformation(Request, status, (ULONG_PTR)length);
}
else
{
WdfRequestComplete(Request, STATUS_INSUFFICIENT_RESOURCES);
}
}
WdfSpinLockRelease(pdoData->port->InBufLock);
TraceEvents(TRACE_LEVEL_INFORMATION, DBG_READ,"<-- %s\n", __FUNCTION__);
return;
}
VOID
VIOSerialPortRead(
IN WDFQUEUE Queue,
IN WDFREQUEST Request,
IN size_t Length
)
{
PRAWPDO_VIOSERIAL_PORT pdoData = RawPdoSerialPortGetData(WdfIoQueueGetDevice(Queue));
PVIOSERIAL_PORT pport = pdoData->port;
size_t length;
NTSTATUS status;
PVOID systemBuffer;
TraceEvents(TRACE_LEVEL_INFORMATION, DBG_READ, "-->%s\n", __FUNCTION__);
status = WdfRequestRetrieveOutputBuffer(Request, Length, &systemBuffer, &length);
if (!NT_SUCCESS(status))
{
WdfRequestComplete(Request, status);
return;
}
WdfSpinLockAcquire(pport->InBufLock);
if (!VIOSerialPortHasDataLocked(pport))
{
if (!pport->HostConnected)
{
status = STATUS_INSUFFICIENT_RESOURCES;
length = 0;
}
else
{
ASSERT (pport->PendingReadRequest == NULL);
status = WdfRequestMarkCancelableEx(Request,
VIOSerialPortReadRequestCancel);
if (!NT_SUCCESS(status))
{
length = 0;
}
else
{
pport->PendingReadRequest = Request;
Request = NULL;
}
}
}
else
{
length = (ULONG)VIOSerialFillReadBufLocked(pport, systemBuffer, length);
if (!length)
{
status = STATUS_INSUFFICIENT_RESOURCES;
}
}
WdfSpinLockRelease(pport->InBufLock);
if (Request != NULL)
{
// we are completing the request right here, either because of
// an error or because data was available in the input buffer
WdfRequestCompleteWithInformation(Request, status, (ULONG_PTR)length);
}
TraceEvents(TRACE_LEVEL_INFORMATION, DBG_READ,"<-- %s\n", __FUNCTION__);
}
