[U-Boot] [PATCH 0/6] Add ARMv8 PSCI framework

[Hongbo Zhang]

I just explained why and how I tried to place newly introduced macros
in arch/arm/cpu/armv8/Kconfig and  board/freescale/ls1043ardb/Kconfig.

As to the order, is it compulsory to define such a CONFIG_* before
using it, even there is #ifdef test when using it?

If yes, I have to define all the four new CONFIG_* into
arch/arm/cpu/armv8/Kconfig along with the adding-secure-sections
patch, but default values have to be set which is bit hard to handle,
for the CONFIG_ARMV8_PSCI_NR_CPUS, we can set a 4 although it isn't
correct in most cases, but for the CONFIG_ARMV8_SECURE_BASE, we don't
know its default value, it is really platform specific.

In my implementation, I just wanted to treat CONFIG_ARMV8_PSCI_NR_CPUS
and CONFIG_CPU_PER_CLUSTER as same as CONFIG_ARMV8_SECURE_BASE, since
they are all platform specific.

And for the CONFIG_ARMV8_PSCI_NR_CPUS, it is slightly different form
ARMv7's, if not defined, the lds file still works:
#ifdef CONFIG_ARMV8_PSCI_NR_CPUS
. = . + CONFIG_ARMV8_PSCI_NR_CPUS * ARM_PSCI_STACK_SIZE;
#else
. = . + 4 * ARM_PSCI_STACK_SIZE;
#endif



On Wed, Sep 28, 2016 at 3:16 PM, Hongbo Zhang <macro.wave.z at gmail.com> wrote:
> On Wed, Sep 28, 2016 at 1:23 AM, Tom Rini <trini at konsulko.com> wrote:
>> On Tue, Sep 27, 2016 at 05:29:00PM +0800, macro.wave.z at gmail.com wrote:
>>> From: Hongbo Zhang <hongbo.zhang at nxp.com>
>>>
>>> This patch set introduces ARMv8 PSCI framework, all the PSCI functions are
>>> implemented a default dummy one, it is up to each platform to implement their
>>> own specific ones.
>>>
>>> The first 1/6 patch is a prepare clean up for adding ARMv8 PSCI.
>>> Patches 2/6 to 5/6 introduce new ARMv8 framework and set it up.
>>> The last 6/6 adds a most simple implementation on NXP LS1043 platform, to
>>> verify this framework.
>>>
>>> This patch set mainly introduces ARMv8 PSCI framework, for easier review and
>>> merge, further PSCI implementation on LS1043 is coming later.
>>>
>>> Hongbo Zhang (6):
>>>   ARMv8: LS1043A: change macro CONFIG_ARMV8_PSCI definition
>>>   ARMv8: Add secure sections for PSCI text and data
>>>   ARMv8: Add basic PSCI framework
>>>   ARMv8: Setup PSCI memory and dt
>>>   ARMv8: Enable SMC instruction
>>>   ARMv8: LS1043A: Enable LS1043A default PSCI support
>>
>> Conceptually this is good.  I have some issues around order of the
>> patches, and where the Kconfig entries end up.  Looking over the series
>> we introduce usage of some CONFIG symbols prior to declaring them in
>> Kconfig.  This is more of a hard no now as it will break bisecting when
>> the test for no new CONFIG symbols is tripped.  The other problem is
>> that I think the symbols you're adding in
>> board/freescale/ls1043ardb/Kconfig need to be in
>> arch/arm/cpu/armv8/Kconfig and then use default ... if ... to give the
>> right address for the layerscape boards.
>
> Thanks Tom for quick response.
>
> For config options introduced:
> CONFIG_ARMV8_PSCI
> CONFIG_ARMV8_PSCI_NR_CPUS
> CONFIG_CPU_PER_CLUSTER
> CONFIG_ARMV8_SECURE_BASE
>
> I've tested adding patch one by one, there is no problem with the
> check-config script.
>
> And my idea was like this: let the CONFIG_ARMV8_PSCI to be an overall
> switch, and if it is enabled even without the other three ones, the
> default PSCI still works, as I've tested, this really works because
> any of the other three macros, when used, there is a #ifdef to check
> if it exists, if no, a default value is used or it isn't used at all.
> The later three macros, because they are platform specific so I
> intended to let every platform to define them.
>
> This is slightly different from ARMv7, plan was if this get accepted,
> I would like to send patch to update ARMv7's.
>
>>
>> --
>> Tom