[PATCH RFC] irqchip: gic-v3: Support forced cpu irq affinity setting

[Alim Akhtar]

On 08/08/2017 02:52 PM, Marc Zyngier wrote:
> On 08/08/17 10:04, Alim Akhtar wrote:
>> Skip check for online cpu mask when setting irq affinity of per cpu timer
>> during early startup of not yet online cpu.
>>
>> Signed-off-by: Shaik Ameer Basha <shaik.ameer at samsung.com>
>> Signed-off-by: Aswani Reddy <aswani.reddy at samsung.com>
>> Signed-off-by: Alim Akhtar <alim.akhtar at samsung.com>
>> ---
>>   drivers/irqchip/irq-gic-v3.c | 7 ++++++-
>>   1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> Currently when non boot CPUs comes up and if setting of IRQ affinity gets called
>> before cpu online status gets updated, gic_mpidr_to_affinity() returns
>> undesirable cpu number. Using __force__ flag ignore cpu_online_mask and setup
>> the intended cpu affinity for the irq.
>>
>> The same approch is used in gicv2
>> (commit: ffde1de64012c: irqchip: Gic: Support forced affinity setting)
>>
>> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
>> index dbffb7a..c238c64 100644
>> --- a/drivers/irqchip/irq-gic-v3.c
>> +++ b/drivers/irqchip/irq-gic-v3.c
>> @@ -640,11 +640,16 @@ static void gic_smp_init(void)
>>   static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
>>   			    bool force)
>>   {
>> -	unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
>> +	unsigned int cpu;
>>   	void __iomem *reg;
>>   	int enabled;
>>   	u64 val;
>>   
>> +	if (!force)
>> +		cpu = cpumask_any_and(mask_val, cpu_online_mask);
>> +	else
>> +		cpu = cpumask_first(mask_val);
>> +
>>   	if (cpu >= nr_cpu_ids)
>>   		return -EINVAL;
>>   
>>
> 
> See
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/commit/?h=irq/irqchip-4.13&id=65a30f8b300107266f316d550f060ccc186201a3
> 

Thanks Marc for above link. Is this already queued in some tree? I can't 
find this is linux-next.

> 	M.
>