Re: Copying user space data to PCI memory

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Hi Arun,

On Sat, May 16, 2009 at 5:48 PM, arun c <arun.edarath@xxxxxxxxx> wrote:
> Hi all,
>
> I want to copy data from user space to PCI memory.
>
> I mapped the PCI memory of the card by,
>
> 1)pci_request_regions(pci_dev, DEVICE_NAME);
> 2)buffer_addr = pci_iomap(pci_dev, 1, 1024);
>
> Now I want to write data supplied by the
> user to buffer_addr(BAR1 pre-fetch-able memory
> of the device)
>
> I did like this:
>
> copy_from_user(buffer_addr, usr_addr, 1024)
>
> This method is working fine on an X86 running
> linux 2.6.27 kernel. I can see the data clearly copied.
>
> I want to know is this legal for all the platforms? and for
> older kernels starting from 2.6.16?
>
> If the above method is totally legal then can I use
> copy_to_user(usr_addr, buffer_addr, 1024) also?
>
AFAIK, yes.
If you look at the source, the code for copy_from_user/copy_to_user
belongs to the arch directory which according to the semantics means
that its platform specific.
Also, I could see that its defined for all the platforms but its
prototype differs.


> Regards,
> Arun C
>
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>



-- 
Regards,
Sandeep.





 	
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