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

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Logan Gunthorpe <logang@deltatee.com>
Cc: Fabio Estevam <festevam@gmail.com>,
	Horia Geanta <horia.geanta@nxp.com>,
	Aymen Sghaier <aymen.sghaier@nxp.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Linux-Arch <linux-arch@vger.kernel.org>,
	"linux-ntb@googlegroups.com" <linux-ntb@googlegroups.com>,
	"open list:HARDWARE RANDOM NUMBER GENERATOR CORE" 
	<linux-crypto@vger.kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Dan Douglass <dan.douglass@nxp.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH v18 6/7] crypto: caam: cleanup CONFIG_64BIT ifdefs when using io{read|write}64
Date: Wed, 4 Jul 2018 20:21:58 +0300	[thread overview]
Message-ID: <CAHp75Vfd2wcUV_dY5ns28+9aC32=OiVExuxOFu7ZjMU2dYuA4Q@mail.gmail.com> (raw)
In-Reply-To: <CAHp75VdtkYRWyKnD+wXo_Z_t=EK9dAOTFzbnHmraSt80sAmyHA@mail.gmail.com>

On Wed, Jul 4, 2018 at 8:16 PM, Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Wed, Jul 4, 2018 at 8:13 PM, Logan Gunthorpe <logang@deltatee.com> 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