IoFreeMapRegisters

VOID
IoFreeMapRegisters(
IN PADAPTER_OBJECT AdapterObject,
IN PVOID MapRegisterBase,
IN ULONG NumberOfMapRegisters
);

IoFreeMapRegisters releases a set of map registers that were saved from a call to IoAllocateAdapterChannel when the driver of a busmaster device has completed the current packet-based DMA transfer request.

Parameters

AdapterObject: Is the pointer to the adapter object representing the busmaster adapter. This pointer was returned by HalGetAdapter when the driver initialized.
MapRegisterBase: Points to the handle returned by the driver’s call to IoAllocateAdapterChannel.
NumberOfMapRegisters: Specifies the number of map registers to be released, which must match the number specified in the preceding call to IoAllocateAdapterChannel.

Comments

IoFreeMapRegisters releases map registers previously allocated by a call to IoAllocateAdapterChannel and retained by a busmaster device driver’s AdapterControl routine.

Callers of IoFreeMapRegisters must be running at IRQL DISPATCH_LEVEL.