Hi Randy,
On Thu, Oct 13, 2011 at 4:00 AM, Randy Dunlap <rdunlap@xxxxxxxxxxxx> wrote:
> On 10/11/2011 02:23 AM, Sumit Semwal wrote:
>> Add documentation for dma buffer sharing framework, explaining the
>> various operations, members and API of the dma buffer sharing
>> framework.
>>
>> Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
>> Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxx>
>> ---
>> Documentation/dma-buf-sharing.txt | 210 +++++++++++++++++++++++++++++++++++++
<snip>
>> + if the new buffer-user has stricter 'backing-storage constraints', and the
>> + exporter can handle these constraints, the exporter can just stall on the
>> + get_scatterlist till all outstanding access is completed (as signalled by
>
> until
>
Thanks for your review; I will update all these in the next version.
>> + put_scatterlist).
>> + Once all ongoing access is completed, the exporter could potentially move
>> + the buffer to the stricter backing-storage, and then allow further
>> + {get,put}_scatterlist operations from any buffer-user from the migrated
>> + backing-storage.
>> +
>> + If the exporter cannot fulfill the backing-storage constraints of the new
>> + buffer-user device as requested, dma_buf_attach() would return an error to
>> + denote non-compatibility of the new buffer-sharing request with the current
>> + buffer.
>> +
>> + If the exporter chooses not to allow an attach() operation once a
>> + get_scatterlist has been called, it simply returns an error.
>> +
>> +- mmap file operation
>> + An mmap() file operation is provided for the fd associated with the buffer.
>> + If the exporter defines an mmap operation, the mmap() fop calls this to allow
>> + mmap for devices that might need it; if not, it returns an error.
>> +
>> +References:
>> +[1] struct dma_buf_ops in include/linux/dma-buf.h
>> +[2] All interfaces mentioned above defined in include/linux/dma-buf.h
>
>
> --
> ~Randy
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
>
Best regards,
~Sumit.
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