MmUnmapIoSpace function (wdm.h)

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

Syntax

VOID MmUnmapIoSpace(
  [in] PVOID  BaseAddress,
  [in] SIZE_T NumberOfBytes
);

Parameters

[in] BaseAddress

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

[in] NumberOfBytes

Specifies the number of bytes that were mapped.

Return value

None

Remarks

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.

Requirements

See also

MmMapIoSpace