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.

See Also

HalAllocateCommonBuffer, HalGetAdapter, IoAllocateAdapterChannel, IoMapTransfer