custom Pci netdevice using DMA

custom Pci netdevice using DMA

[RANDAZZO]

All:

I have a PCI device (uses DMA), that was originally designed for an RTOS...

The device takes physical host address pointers (written to the card via bar
space).

When data is received from the network, the pci card will DMA the data
directly to the
host asynchronously....

after a certain amt of data is received, an interrupt is gen'd and the host
goes and looks at the data..

For transmitting, the host gives the pci device a physical host address
value and the pci device will DMA the
data, from the host, that is pointed to......

...............................
This above design does not work in Linux 2.4.  I understand that I must use
the dma functions (pci_alloc_*,
virt_to_bus, etc), but can't figure out what is the best way???

Any help?
Feel free to ask more details if needed.....

-Mike

 
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Re: custom Pci netdevice using DMA

[Jeff Garzik]

RANDAZZO@ddc-web.com wrote:
> All:
> 
> I have a PCI device (uses DMA), that was originally designed for an RTOS...
> 
> The device takes physical host address pointers (written to the card via bar
> space).
> 
> When data is received from the network, the pci card will DMA the data
> directly to the
> host asynchronously....
> 
> after a certain amt of data is received, an interrupt is gen'd and the host
> goes and looks at the data..
> 
> For transmitting, the host gives the pci device a physical host address
> value and the pci device will DMA the
> data, from the host, that is pointed to......
> 
> ...............................
> This above design does not work in Linux 2.4.  I understand that I must use
> the dma functions (pci_alloc_*,
> virt_to_bus, etc), but can't figure out what is the best way???


Documentation/DMA-mapping.txt, Documentation/DMA-API.txt

	Jeff