[RFC Part2 v1 03/21] x86, irq: Save destination CPU ID in irq_cfg

Jiang Liu
2014-09-17T02:24:59Z

On 2014/9/17 1:47, Thomas Gleixner wrote:
>
>
> On Thu, 11 Sep 2014, Jiang Liu wrote:
>
>> Cache destination CPU APIC ID into struct irq_cfg when assigning vector
>> for interrupt. Upper layer just needs to read the cached APIC ID instead
>> of calling apic->cpu_mask_to_apicid_and(), it helps to hide APIC driver
>> details from IOAPIC/HPET/MSI drivers..
>>
>> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
>> ---
>> arch/x86/include/asm/hw_irq.h | 1 +
>> arch/x86/kernel/apic/vector.c | 4 ++++
>> 2 files changed, 5 insertions(+)
>>
>> diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
>> index 7624fffc2822..3d51d74d6c01 100644
>> --- a/arch/x86/include/asm/hw_irq.h
>> +++ b/arch/x86/include/asm/hw_irq.h
>> @@ -116,6 +116,7 @@ struct irq_data;
>> struct irq_cfg {
>> cpumask_var_t domain;
>> cpumask_var_t old_domain;
>> + unsigned int dest_apicid;
>> u8 vector;
>> u8 move_in_progress : 1;
>> #ifdef CONFIG_IRQ_REMAP
>> diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
>> index 7562cb15b3bd..287ae4e8d500 100644
>> --- a/arch/x86/kernel/apic/vector.c
>> +++ b/arch/x86/kernel/apic/vector.c
>> @@ -188,6 +188,10 @@ next:
>> }
>> free_cpumask_var(tmp_mask);
>
> Lacks a comment what this call is actually doing.
How about this?
/* cache destination APIC IDs into cfg->dest_apicid */
Regards!
Gerry
>
>> + if (!err)
>> + err = apic->cpu_mask_to_apicid_and(mask, cfg->domain,
>> + &cfg->dest_apicid);
>> +
>
> Thanks,
>
> tglx
>