Re: [PATCH v18 6/7] crypto: caam: cleanup CONFIG_64BIT ifdefs when using io{read|write}64

From: Andy Shevchenko
Date: Wed Jul 04 2018 - 13:22:06 EST

On Wed, Jul 4, 2018 at 8:16 PM, Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Wed, Jul 4, 2018 at 8:13 PM, Logan Gunthorpe <logang@xxxxxxxxxxxx> wrote:
>> On 7/4/2018 11:10 AM, Andy Shevchenko wrote:
>>> We have an iDMA 32-bit hardware (see drivers/dma/dw/) which has an
>>> extension 64-bit registers where only one of them has a specific bit
>>> to "commit" the changes written to all of them. And by some very
>>> unknown reason that bit is in lo part which automatically means we
>>> must to write it last.
>> And it supports both BE and LE? And in both cases it's the lo part?
> It's only LE for now.
> P.S. If you more interested in code in kernel look for idma32_fifo_partition()
> (While the bit is set in each of 32-bit part, it's actually present in
> only one place)

I think it doesn't contradict with what you are saying rather supports it.

I would expect to have lo-hi and hi-lo semantics done according to the
data flow, not to the address.

With Best Regards,
Andy Shevchenko