On 03/21/2010 06:56 PM, Michael Ellerman wrote:
> On Sun, 2010-03-21 at 18:36 -0700, Yinghai Lu wrote:
>> From: Ian Campbell <ian.campb...@citrix.com>
> ...
>> To replace the x86 arch_init_chip_data functionality
>> irq_to_desc_alloc_node now takes a pointer to a function to allocate
>> the chip data. This is necessary to ensure the allocation happens
>> under the correct locking at the core level. On PowerPC and SH
>> architectures (the other users of irq_to_desc_alloc_node) pass in NULL
>> which retains existing chip_data behaviour.
> ...
>>
>> -v4: yinghai add irq_to_desc_alloc_node_x...
>> so could leave default path not changed...
>
> Apologies for not noticing this sooner, but ..
>
>> --- a/arch/powerpc/kernel/irq.c
>> +++ b/arch/powerpc/kernel/irq.c
>> @@ -1088,7 +1088,7 @@ int arch_early_irq_init(void)
>> return 0;
>> }
>>
>> -int arch_init_chip_data(struct irq_desc *desc, int node)
>> +int arch_init_irq_desc(struct irq_desc *desc, int node, init_chip_data_fn
>> fn)
>> {
>> desc->status |= IRQ_NOREQUEST;
>> return 0;
>
> This is a bit feral, that is the init_chip_data_fn.
>
> It seems like it only exists to support the following on x86:
>
>> +int arch_init_irq_desc(struct irq_desc *desc, int node,
>> + init_chip_data_fn init_chip_data)
>> +{
>> + if (!init_chip_data)
>> + return x86_init_chip_data(desc, node);
>> +
>> + return init_chip_data(desc, node);
>> +}
>
> Which is really just a hack to avoid an if (xen) check isn't it?
arch/powerpc/kernel/irq.c | 2 +-
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 64f6f20..cafd378 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -1088,7 +1088,7 @@ int arch_early_irq_init(void)
return 0;
}
-int arch_init_chip_data(struct irq_desc *desc, int node)
+int arch_init_irq_desc(struct irq_desc *desc, int node, init_chip_data_fn fn)
{
desc->status |= IRQ_NOREQUEST;
return 0;
so this patch only change one line with powerpc code.
>
> It looks to me like this should just be done via a current machine
> vector or platform routine, in the same way as powerpc and (I think)
> ia64, ie:
>
>> +int arch_init_irq_desc(struct irq_desc *desc, int node)
>> +{
>> + return current_machine->init_chip_data(desc, node);
>> +}
>
looks like xen in same run time, some irqs need x86_init_chip_data,
and some may need xen_init_chip_data later.
Thanks
Yinghai
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