MmUnmapIoSpace

The MmUnmapIoSpace routine unmaps a specified range of physical addresses previously mapped by MmMapIoSpace.

VOID 
  MmUnmapIoSpace(
    IN PVOID  BaseAddress,
    IN SIZE_T  NumberOfBytes
    );

Parameters

BaseAddress

Pointer to the base virtual address to which the physical pages were mapped.

NumberOfBytes

Specifies the number of bytes that were mapped.

Return Value

None

Headers

Declared in wdm.h and ntddk.h. Include wdm.h or ntddk.h.

Comments

If a driver calls MmMapIoSpace during device start-up, it must call MmUnmapIoSpace when it receives a PnP stop-device or remove-device IRP for the same device object.

Callers of MmUnmapIoSpace must be running at IRQL = PASSIVE_LEVEL.

See Also

MmMapIoSpace