scatterlist copy to buffer and copy back

scatterlist copy to buffer and copy back

[leo kirotawa]

Hi there,

I'm facing with an issue that from a module the user sends a scatterlist
which has sizes not power of two and because that I can not handle it
properly in my module in other side.
An example is:
- scatterlist entries size 3 and data size 4096.
- in other side module needs to build blocks in power of two sizes, but
since scatterlist are size 3 or any size not power of two it's not
possible.
>From my understanding, entries gives a segment's size of the buffer passed.
And each entries has an address to this piece.
So if buffer is something like this:

|                                                | <- buffer
scatter list will be spread in memory like this:
| entry | entry | entry | ..., of course spread in memory.

As a solution I'm thinking in copy those scatterlist to a buffer and
process this buffer as a power of two sizes pieces, and so put the result
in the output buffer and into the output scatterlist size not power of two.
I know it seems a stupid solution, since scatterlist were done to help
spread data from a buffer in not continual space and improve performance.
So...

*Question is*, is there any way I can copy a scatterlist size 3 to another
scatterlist size power of two or any size? I didn't see any function in
scatterlist.c api for this, just those solutions to copy from to buffer or
buffer to scatterlist.

Any suggestions or tips are very welcome :)
Thanks in advance,
-- 

----------------------------------------------
Le?nidas S. Barbosa (Kirotawa)
blog: corecode.wordpress.com
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