[PATCH 4/5] ARM: EXYNOS: Add support for Exynos secure firmware

Kyungmin Park kyungmin.park at samsung.com
Sat Sep 22 01:57:09 EDT 2012


On 9/22/12, Olof Johansson <olof at lixom.net> wrote:
> On Wed, Sep 19, 2012 at 3:10 AM, Tomasz Figa <t.figa at samsung.com> wrote:
>> Hi Olof,
>>
>> On Saturday 15 of September 2012 17:44:55 Olof Johansson wrote:
>>> On Thu, Sep 13, 2012 at 10:13:37AM +0200, Tomasz Figa wrote:
>>> > +static void __iomem *exynos_cpu_boot_reg(int cpu)
>>> > +{
>>> > +   return S5P_VA_SYSRAM_NS + 0x1c + 4*cpu;
>>> > +}
>>>
>>> This communication area in sysram should probably be seen as a part of
>>> the firmware interface. It should thus be defined as part of the binding
>>> instead, i.e.  through a reg property or similar there. That also would
>>> make it easy to convert to using ioremap() instead of iodesc tables,
>>> which always a nice thing.
>>
>> The problem with SYSRAM_NS is that it might be also used in other code,
>> not
>> related to firmware only. I don't know exactly all the use cases for it.
>
> If you don't know the use cases, and the use cases are not in the
> kernel tree that we care about here (upstream), then there's really
> nothing to worry about. It's after all just a define that's moved to
> an ioremap, if there's some out of tree code that needs the old legacy
> define then it can be added in whatever out-of-tree code that uses it.
> Right?
Now this address is used at cpu boot, cpuidle, inform at this time.
As it touched at several places, it's defined at iodesc. if it changed
with ioremap, it has to export remaped address and each codes should
use it.

As I wrote at cover letter, if you want to use ioremap, it can be
modified. however can you merge firmware codes itself? since ioremap
is not related with trustzone  or firmware issues and it's exynos
specific implementation issues. Right?

Thank you,
Kyungmin Park
>
>> Is it really a big problem or we could let it be for now, merge the
>> patches
>> for firmware and then convert SYSRAM_NS to dynamic mapping when its
>> situation clarifies?
>
> What do you expect is required to clarify the situation, and when do
> you expect that to happen?
>
>
> -Olof
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