MmUnmapIoSpace function

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

Syntax

NTKERNELAPI VOID MmUnmapIoSpace(
  PVOID  BaseAddress,
  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

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

   
Windows version Available starting with Windows 2000.
Target Platform Universal
Header wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library NtosKrnl.lib
DLL NtosKrnl.exe
IRQL "<=DISPATCH_LEVEL"

See Also

MmMapIoSpace