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MmUnmapIoSpace routine

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

BaseAddress [in]

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

NumberOfBytes [in]

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

Target platform

Universal

Version

Available starting with Windows 2000.

Header

Wdm.h (include Wdm.h, Ntddk.h, or Ntifs.h)

Library

Ntoskrnl.lib

IRQL

<=DISPATCH_LEVEL

See also

MmMapIoSpace

 

 

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