[Patch] irqdomain: Introduce new interfaces to support hierarchy irqdomains

[Joe.C]

On Mon, 2014-09-22 at 16:17 +0800, Jiang Liu wrote:
> @@ -388,7 +389,6 @@ EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
>  unsigned int irq_create_mapping(struct irq_domain *domain,
>  				irq_hw_number_t hwirq)
>  {
> -	unsigned int hint;
>  	int virq;
>  
>  	pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
> @@ -410,12 +410,8 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
>  	}
>  
>  	/* Allocate a virtual interrupt number */
> -	hint = hwirq % nr_irqs;
> -	if (hint == 0)
> -		hint++;
> -	virq = irq_alloc_desc_from(hint, of_node_to_nid(domain->of_node));
> -	if (virq <= 0)
> -		virq = irq_alloc_desc_from(1, of_node_to_nid(domain->of_node));
> +	virq = irq_domain_alloc_descs(-1, 1, hwirq,
> +				      of_node_to_nid(domain->of_node));

If I read this correct, the resulting virq is different after your
change.

>  	if (virq <= 0) {
>  		pr_debug("-> virq allocation failed\n");
>  		return 0;
> @@ -490,7 +486,10 @@ unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
>  	}
>  
>  	/* Create mapping */
> -	virq = irq_create_mapping(domain, hwirq);
> +	if (irq_domain_is_hierarchy(domain))
> +		virq = irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, irq_data);
> +	else
> +		virq = irq_create_mapping(domain, hwirq);
>  	if (!virq)
>  		return virq;

hwirq returned from xlat above is lost. Without hwirq or virq, how do we
know which irq are we working for?
Also, if the irq_desc/irq_data was already created, this will create
another one. Should we do irq_find_mapping just like irq_create_mapping?

> +int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
> +			    unsigned int nr_irqs, int node, void *arg,
> +			    bool realloc)
> +{
> +	int i, ret, virq;
> +
> +	if (domain == NULL) {
> +		domain = irq_default_domain;
> +		if (WARN(!domain, "domain is NULL; cannot allocate IRQ\n"))
> +			return -EINVAL;
> +	}
> +
> +	if (!domain->ops->alloc) {
> +		pr_debug("domain->ops->alloc() is NULL\n");
> +		return -ENOSYS;
> +	}
> +
> +	if (realloc && irq_base >= 0) {
> +		virq =  irq_base;
                         ^
extra space here.

Joe.C