Re: [PATCH] ARM: owl: smp: Drop owl_secondary_boot()

From: Gregory CLEMENT
Date: Fri Jul 07 2017 - 03:34:29 EST


Hi Florian,

On jeu., juil. 06 2017, Florian Fainelli <f.fainelli@xxxxxxxxx> wrote:

> On 07/06/2017 10:38 AM, Alexandre Belloni wrote:
>> On 06/07/2017 at 19:17:28 +0200, Andreas FÃrber wrote:
>>> Am 05.07.2017 um 04:36 schrieb Florian Fainelli:
>>>> On July 4, 2017 4:32:18 PM PDT, "Andreas FÃrber" <afaerber@xxxxxxx> wrote:
>>>>> Commit 18cfd9429d8a82c49add8f3ca9d366599bfcac45 ("ARM: owl: smp: Drop
>>>>> bogus holding pen") simplified the S500 SMP code by removing a loop for
>>>>> pen_release in owl_secondary_boot(). Since then it is only calling
>>>>> owl_v7_invalidate_l1() before branching to secondary_startup().
>>>>>
>>>>> The owl_v7_invalidate_l1() assembler function is superfluous, too.
>>>>> Therefore drop owl_secondary_boot() and use secondary_boot() directly.
>>>>>
>>>>> Cc: David Liu <liuwei@xxxxxxxxxxxxxxxx>
>>>>> Signed-off-by: Andreas FÃrber <afaerber@xxxxxxx>
>>>>> ---
>>>>
>>>>> - writel(virt_to_phys(owl_secondary_startup),
>>>>> + writel(virt_to_phys(secondary_startup),
>>>>> timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
>>>>
>>>> This is a kernel symbol so please use __pa_symbol() here, also you
>>>> might want to build with CONFIG_DEBUG_VIRTUAL and see if you get
>>>> other warnings about using virt_to_phys() in the owl platform code
>>>> (I did not check if there are other uses)
>>>
>>> Thanks for the report. There are no other such uses in mach-actions, but
>>> git-grep'ing for virt_to_phys in arch/arm/mach-* I spot at least one
>>> other such usage in mach-oxnas:
>>>
>>> arch/arm/mach-oxnas/platsmp.c:
>>> writel(virt_to_phys(ox820_secondary_startup),
>>>
>>> as well as this in mach-mvebu:
>>>
>>> arch/arm/mach-mvebu/platsmp.c: writel(virt_to_phys(boot_addr), base +
>>> MV98DX3236_CPU_RESUME_ADDR_REG);
>>>
>>> and these in mach-at91:
>>>
>>> arch/arm/mach-at91/pm.c: pm_bu->canary = virt_to_phys(&canary);
>>> arch/arm/mach-at91/pm.c: pm_bu->resume = virt_to_phys(cpu_resume);
>>>
>>
>> They can probably use __pa_symbol() (I must admit I didn't know about
>> it before this email)
>
> This is fine, do you mind sending fixes for the at91 parts? Gregory, can
> you also fix the mv98dx3236 platform SMP code?

Yes sure, actually, for Armada XP we already use __pa_symbol() but from
an other file that why I didn't pay attention on it.

Gregory

>
> Thanks!
> --
> Florian

--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com