NetDmaRegisterProvider function (netdma.h)

Syntax

NET_DMA_EXPORT NTSTATUS NetDmaRegisterProvider(
  [in] PVOID                             ProviderContext,
  [in] PVOID                             *pNetDmaProviderHandle,
  [in] PNET_DMA_PROVIDER_CHARACTERISTICS ProviderCharacteristics
);

Parameters

[in] ProviderContext

A pointer to a block of driver-allocated context information that stores information about the DMA provider. NetDMA passes the context information in subsequent calls to ProviderXxx functions that required a DMA provider context.

[in] pNetDmaProviderHandle

A pointer to a value that is a handle that NetDmaRegisterProvider supplies to identify the DMA provider. The DMA provider driver passes this handle to NetDmaXxx functions that require a provider handle.

[in] ProviderCharacteristics

A pointer to a NET_DMA_PROVIDER_CHARACTERISTICS structure that defines the characteristics of the DMA provider.

Return value

NetDmaRegisterProvider can return one of the following values:

Remarks

DMA provider drivers call the NetDmaRegisterProvider function to register a DMA provider. DMA provider drivers call NetDmaRegisterProvider in their AddDevice routine.

In the AddDevice routine, the DMA provider driver calls the IoCreateDevice function to create a functional device object (FDO) and inserts it at the top of the device stack. The DMA provider driver then calls NetDmaRegisterProvider to register the associated DMA provider.

The DMA provider driver supplies a NET_DMA_PROVIDER_CHARACTERISTICS structure at the ProviderCharacteristics parameter of NetDmaRegisterProvider. The NET_DMA_PROVIDER_CHARACTERISTICS structure specifies the characteristics for a NetDMA provider, including the entry points for the ProviderXxx functions.

The DMA provider driver provides a pointer to a block of driver-allocated context information at the ProviderContext parameter of NetDmaRegisterProvider. This context area stores information about the DMA provider. The NetDMA interface passes the context information in subsequent calls to ProviderXxx functions that require a DMA provider context.

When NetDmaRegisterProvider returns, it provides a handle at the location that the pNetDmaProviderHandle parameter specifies. The NetDMA interface assigns this handle to identify the DMA provider. The DMA provider driver uses this handle in all subsequent calls to NetDmaXxx functions that are associated with the DMA provider.

If a computer supports MSI-X, the NetDMA interface, while in the context of the NetDmaRegisterProvider function, calls the DMA provider driver's ProviderSetDmaChannelCpuAffinity function to specify the CPU affinity of the interrupt for each DMA channel.

If a computer supports MSI-X, the DMA provider driver can specify interrupt affinities while handling the IRP_MN_FILTER_RESOURCE_REQUIREMENTS IRP. After the AddDevice routine successfully returns, the Plug and Play (PnP) manager sends the IRP_MN_FILTER_RESOURCE_REQUIREMENTS IRP for the DMA provider. The DMA provider driver must attempt to allocate MSI-X interrupt resources according to affinity parameters that the NetDMA interface passed to ProviderSetDmaChannelCpuAffinity.

To deregister a DMA provider, a DMA provider driver calls the NetDmaDeregisterProvider function.

Requirements

See also

AddDevice

IoCreateDevice

NetDmaDeregisterProvider