NdisQueryMapRegisterCount

NDIS_STATUS
NdisQueryMapRegisterCount(
IN NDIS_INTERFACE_TYPE BusType,
OUT PUINT MapRegisterCount
);

NdisQueryMapRegisterCount returns the maximum number of available map registers in the current platform.

Parameters

BusType

Specifies the I/O bus interface type of the caller’s busmaster DMA NIC, which usually is the type of I/O bus on which the NIC is connected, as one of the following:

NdisInterfaceInternal: Specifies a host-specific internal interface.
NdisInterfaceIsa: Specifies the ISA interface.
NdisInterfaceEisa: Specifies the extended ISA (EISA) interface.
NdisInterfaceMca: Specifies the MicroChannel architecture interface.
NdisInterfaceTurboChannel: Specifies the Turbo Channel interface.
NdisInterfacePci: Specifies the Peripheral Component Interconnect (PCI) interface.
NdisInterfacePcMcia: Specifies the Personal Computer Memory Card International Association (PCMCIA) interface.

MapRegisterCount

Points to a caller-supplied variable in which this function returns the maximum number of map registers available to the caller.

Return Value

NdisQueryMapRegisterCount returns NDIS_STATUS_SUCCESS if the value at MapRegisterCount is valid; otherwise, it returns NDIS_STATUS_NOT_SUPPORTED.

Comments

NdisQueryMapRegisterCount returns information useful only to drivers of busmaster DMA devices.

Busmaster NIC miniports can call NdisQueryMapRegisterCount only during initialization. Such a driver’s MiniportInitialize function should call NdisQueryMapRegisterCount before it calls NdisMAllocateMapRegisters.

Callers of NdisQueryMapRegisterCount run at IRQL PASSIVE_LEVEL.