Hi Sergei,
On Tue, Jun 21, 2016 at 7:49 PM, Sergei Shtylyov
<sergei.shtylyov@xxxxxxxxxxxxxxxxxx> wrote:
> On 06/16/2016 01:27 PM, Geert Uytterhoeven wrote:
>> From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
>> Allow DT configuration of the APMU hardware in the case when the APMU is
>> pointed out in the DTB via the enable-method. The ability to configure
>> the APMU via C code is still kept intact to prevent DTB breakage for older
>> SoCs that do not rely on the enable-method for SMP support.
>>
>> Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
>> [geert: Fix CONFIG_SMP=n build]
>> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>
> [...]
>
>> diff --git a/arch/arm/mach-shmobile/platsmp-apmu.c
>> b/arch/arm/mach-shmobile/platsmp-apmu.c
>> index c1558ef0c590dd3e..0c6bb458b7a45128 100644
>> --- a/arch/arm/mach-shmobile/platsmp-apmu.c
>> +++ b/arch/arm/mach-shmobile/platsmp-apmu.c
>
> [...]
>>
>> +static int shmobile_smp_apmu_boot_secondary_md21(unsigned int cpu,
>> + struct task_struct *idle)
>> +{
>> + /* Error out when hardware debug mode is enabled */
>> + if (rcar_gen2_read_mode_pins() & BIT(21)) {
>> + pr_warn("Unable to boot CPU%u when MD21 is set\n", cpu);
>> + return -ENOTSUPP;
>> + }
>> +
>> + return shmobile_smp_apmu_boot_secondary(cpu, idle);
>> +}
>> +
>> +static struct smp_operations apmu_smp_ops __initdata = {
>> + .smp_prepare_cpus = shmobile_smp_apmu_prepare_cpus_dt,
>> + .smp_boot_secondary = shmobile_smp_apmu_boot_secondary_md21,
>> +#ifdef CONFIG_HOTPLUG_CPU
>> + .cpu_can_disable = shmobile_smp_cpu_can_disable,
>> + .cpu_die = shmobile_smp_apmu_cpu_die,
>> + .cpu_kill = shmobile_smp_apmu_cpu_kill,
>> #endif
>
>
> For the record: it turned out that I tested my non-DT SMP on
> R8A7792/Blanche with MD21 bit set. And I've just made sure it still works
> with this implementation (by commenting out the check above.
> Also, I was going to try the workaround for MD21 I saw in the BSP tree --
Which workaround? I only saw the BSP removed the check, but it didn't mention
why (because E2 and V2H don't need it, or...?).
> perhaps it'll help get R8A7791 working w/MD21 set...
Does your Porter work with the other MD21 setting (and the check commented
out, of coutse)?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
