NetDmaIsr function (netdma.h)

Article
10/21/2021

Note The NetDMA interface is not supported

in Windows 8 and later.

The NetDmaIsr function notifies the NetDMA interface that a DMA transfer interrupt has occurred on a DMA channel.

Syntax

NET_DMA_EXPORT VOID NetDmaIsr(
  [in]  PVOID            NetDmaChannelHandle,
  [in]  PHYSICAL_ADDRESS DmaDescriptor,
  [out] PULONG           pCpuNumber
);

Parameters

[in] NetDmaChannelHandle

A handle that identifies the DMA channel. The DMA provider driver received this handle from the NetDMA interface in a call to the ProviderAllocateDmaChannel function.

[in] DmaDescriptor

The physical address of the DMA descriptor that is associated with the interrupt.

[out] pCpuNumber

The number of the CPU that is associated with the interrupt DPC. The NetDMA interface writes this CPU number at the provided address before NetDmaIsr returns.

Return value

None

Remarks

DMA provider drivers call the NetDmaIsr function in their interrupt service routine (ISR).

If the NET_DMA_INTERRUPT_ON_COMPLETION flag in the ControlFlags member of the NET_DMA_DESCRIPTOR structure is set, the DMA engine should generate an interrupt for the DMA channel after it processes the DMA descriptor. When this flag is cleared, the DMA engine does not generate an interrupt.

Note When the ISR is called, the current DMA descriptor might already be different from the descriptor that triggered the interrupt.

A DMA provider driver should do as little work as possible in its ISR handler. The driver should defer I/O operations to the interrupt DPC handler.

Requirements

Requirement	Value
Minimum supported client	Supported for NetDMA 1.0 drivers in Windows Vista.
Target Platform	Universal
Header	netdma.h (include Netdma.h)
IRQL	DEVICE_LEVEL