Re: [PATCH 04/10] MIPS: Move mips_smp_ipi_init call after prepare_cpus

Jiaxun Yang
2024-06-17T22:10:24Z

在2024年6月17日六月 下午2:53，Huacai Chen写道：
> Hi, Jiaxun
>
> On Mon, Jun 17, 2024 at 5:03 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
>>
>> This will give platform code a genuine chance to setup
>> IPI IRQ in prepare_cpus.
>>
>> This is the best place for platforms to setup IPI as smp_setup
>> is too early for IRQ subsystem.
> mips_smp_ipi_init() is an early_initcall() function, why do you say it
> is in smp_setup()?

Sorry, I was trying to say that smp_setup is not a good point so we should
go prepare_cpus.

The intention of this patch is to move mips_smp_ipi_init to a certain point
so platform would gain control over it.

Thanks
- Jiaxun

>
>
> Huacai
>>
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> ---
>> arch/mips/kernel/smp.c | 11 ++++++++++-
>> 1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
>> index fe053fe52147..ddf96c28e2f0 100644
>> --- a/arch/mips/kernel/smp.c
>> +++ b/arch/mips/kernel/smp.c
>> @@ -375,7 +375,6 @@ static int __init mips_smp_ipi_init(void)
>>
>> return 0;
>> }
>> -early_initcall(mips_smp_ipi_init);
>> #endif
>>
>> /*
>> @@ -460,12 +459,22 @@ void __init smp_cpus_done(unsigned int max_cpus)
>> /* called from main before smp_init() */
>> void __init smp_prepare_cpus(unsigned int max_cpus)
>> {
>> + int rc;
>> +
>> init_new_context(current, &init_mm);
>> current_thread_info()->cpu = 0;
>> mp_ops->prepare_cpus(max_cpus);
>> set_cpu_sibling_map(0);
>> set_cpu_core_map(0);
>> calculate_cpu_foreign_map();
>> +#ifdef CONFIG_GENERIC_IRQ_IPI
>> + rc = mips_smp_ipi_init();
>> + if (rc) {
>> + pr_err("Failed to initialize IPI - disabling SMP");
>> + init_cpu_present(cpumask_of(0));
>> + return;
>> + }
>> +#endif
>> #ifndef CONFIG_HOTPLUG_CPU
>> init_cpu_present(cpu_possible_mask);
>> #endif
>>
>> --
>> 2.43.0
>>

--
- Jiaxun