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

From: Alexandre Belloni
Date: Thu Jul 06 2017 - 13:38:54 EST


On 06/07/2017 at 19:17:28 +0200, Andreas Färber wrote:
> Am 05.07.2017 um 04:36 schrieb Florian Fainelli:
> > On July 4, 2017 4:32:18 PM PDT, "Andreas Färber" <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 Färber <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)


--
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com