NdisFlushBuffer function

Note   NDIS 5. x has been deprecated and is superseded by NDIS 6. x. For new NDIS driver development, see Network Drivers Starting with Windows Vista. For information about porting NDIS 5. x drivers to NDIS 6. x, see Porting NDIS 5.x Drivers to NDIS 6.0.

NdisFlushBuffer flushes the memory region described by a given buffer descriptor from all processor caches.

Syntax

VOID NdisFlushBuffer(
  _In_ PNDIS_BUFFER Buffer,
  _In_ BOOLEAN      WriteToDevice
);

Parameters

• Buffer [in]
  Pointer to a buffer description mapping a buffer from which or into which data is transferred as a bus-master DMA operation.

• WriteToDevice [in]
  Specifies TRUE if the NIC driver calls this function to flush a buffer before making a transfer from host memory to the NIC.

  If the NIC driver specifies FALSE, it must ensure the buffer begins and ends on a cache-line boundary.

Return value

None

Remarks

Drivers of bus-master DMA NICs call NdisFlushBuffer to maintain data integrity in shared memory. Flushing the buffer ensures coherency between the host memory cache and processor physical memory before a DMA transfer to or from the network interface card.

The driver flushes such a buffer when data that it shares with its NIC might be cached. For any transfer between host memory and a bus-master DMA NIC, the miniport driver must flush the buffer before the transfer starts. Such a driver also must ensure that host memory is not accessed until the transfer completes.

Requirements

See also

MiniportHandleInterrupt

NdisMAllocateSharedMemory

NdisMUpdateSharedMemory

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