IoAllocateController

The IoAllocateController routine sets up the call to a driver-supplied ControllerControl routine as soon as the device controller, represented by the given controller object, is available to carry out an I/O operation for the target device, represented by the given device object.

VOID 
  IoAllocateController(
    IN PCONTROLLER_OBJECT  ControllerObject,
    IN PDEVICE_OBJECT  DeviceObject,
    IN PDRIVER_CONTROL  ExecutionRoutine,
    IN PVOID  Context
    );

Parameters

ControllerObject

Pointer to a driver-created controller object, usually representing a physical controller to be allocated for an I/O operation on an attached device.

DeviceObject

Pointer to the device object, representing the target device of the current IRP.

ExecutionRoutine

Pointer to the driver-supplied ControllerControl routine.

Context

Pointer to a driver-determined context, passed to the driver’s ControllerControl routine when it is called.

Return Value

None

Headers

Declared in ntddk.h. Include ntddk.h.

Comments

This routine reserves exclusive access to the hardware controller for the specified device.

The ControllerControl routine returns a value indicating whether the controller remains allocated to the device, either DeallocateObject or KeepObject. If it returns KeepObject, the driver must subsequently call IoFreeController to release the controller object.

Callers of IoAllocateController must be running at IRQL = DISPATCH_LEVEL.

See Also

ControllerControl, IoCreateController, IoDeleteController, IoFreeController