Re: Copying user space data to PCI memory

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sat, May 16, 2009 at 6:33 PM, SandeepKsinha <sandeepksinha@xxxxxxxxx> wrote:
> 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.
>
Sorry, I spoke too early. Its prototype is same.
>
>> Regards,
>> Arun C
>>
>> --
>> To unsubscribe from this list: send an email with
>> "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx
>> Please read the FAQ at http://kernelnewbies.org/FAQ
>>
>>
>
>
>
> --
> Regards,
> Sandeep.
>
>
>
>
>
>
> “To learn is to change. Education is a process that changes the learner.”
>



-- 
Regards,
Sandeep.





 	
“To learn is to change. Education is a process that changes the learner.”
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [DMA Engine]     [Linux Coverity]     [Linux USB]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Greybus]

  Powered by Linux