[PATCH v2] irq: support domains with non-zero hwirq base

[grant.likely@secretlab.ca (Grant Likely)]

Thomas, any objection to this patch?  It's entirely contained within
the irq_domain stuff, so it is pretty well isolated.

It can be merged via arm-soc since it is depended on by some of the
irq work.

g.

On Tue, Oct 11, 2011 at 08:18:58AM -0500, Rob Herring wrote:
> Thomas,
> 
> On 10/04/2011 09:56 PM, Rob Herring wrote:
> > From: Rob Herring <rob.herring@calxeda.com>
> > 
> > Interrupt controllers can have non-zero starting value for h/w irq numbers.
> > Adding support in irq_domain allows the domain hwirq numbering to match
> > the interrupt controllers' numbering.
> > 
> > As this makes looping over irqs for a domain more complicated, add loop
> > iterators to iterate over all hwirqs and irqs for a domain.
> > 
> > Acked-by: Grant Likely <grant.likely@secretlab.ca>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Signed-off-by: Rob Herring <rob.herring@calxeda.com>
> > ---
> > Thomas,
> > 
> > Please ack. I'm dependent on this for adding Calxeda highbank support, so
> > I'd like to take this thru arm-soc tree.
> > 
> 
> Can you please comment?
> 
> Rob
> 
> > v2:
> > - Rebase to tglx's changes in my previous irq domain commit:
> > irq: Fix check for already initialized irq_domain in irq_domain_add
> > - drop NO_IRQ and add WARN_ON in irq_domain_to_irq
> > 
> > Rob
> > 
> >  include/linux/irqdomain.h |   16 +++++++++++++++-
> >  kernel/irq/irqdomain.c    |   12 ++++++------
> >  2 files changed, 21 insertions(+), 7 deletions(-)
> > 
> > diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> > index 3ad553e..99834e58 100644
> > --- a/include/linux/irqdomain.h
> > +++ b/include/linux/irqdomain.h
> > @@ -47,6 +47,7 @@ struct irq_domain_ops {
> >   *            of the irq_domain is responsible for allocating the array of
> >   *            irq_desc structures.
> >   * @nr_irq: Number of irqs managed by the irq domain
> > + * @hwirq_base: Starting number for hwirqs managed by the irq domain
> >   * @ops: pointer to irq_domain methods
> >   * @priv: private data pointer for use by owner.  Not touched by irq_domain
> >   *        core code.
> > @@ -57,6 +58,7 @@ struct irq_domain {
> >  	struct list_head list;
> >  	unsigned int irq_base;
> >  	unsigned int nr_irq;
> > +	unsigned int hwirq_base;
> >  	const struct irq_domain_ops *ops;
> >  	void *priv;
> >  	struct device_node *of_node;
> > @@ -72,9 +74,21 @@ struct irq_domain {
> >  static inline unsigned int irq_domain_to_irq(struct irq_domain *d,
> >  					     unsigned long hwirq)
> >  {
> > -	return d->ops->to_irq ? d->ops->to_irq(d, hwirq) : d->irq_base + hwirq;
> > +	if (d->ops->to_irq)
> > +		return d->ops->to_irq(d, hwirq);
> > +	if (WARN_ON(hwirq < d->hwirq_base))
> > +		return 0;
> > +	return d->irq_base + hwirq - d->hwirq_base;
> >  }
> >  
> > +#define irq_domain_for_each_hwirq(d, hw) \
> > +	for (hw = d->hwirq_base; hw < d->hwirq_base + d->nr_irq; hw++)
> > +
> > +#define irq_domain_for_each_irq(d, hw, irq) \
> > +	for (hw = d->hwirq_base, irq = irq_domain_to_irq(d, hw); \
> > +	     hw < d->hwirq_base + d->nr_irq; \
> > +	     hw++, irq = irq_domain_to_irq(d, hw))
> > +
> >  extern void irq_domain_add(struct irq_domain *domain);
> >  extern void irq_domain_del(struct irq_domain *domain);
> >  #endif /* CONFIG_IRQ_DOMAIN */
> > diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> > index b57a377..200ce83 100644
> > --- a/kernel/irq/irqdomain.c
> > +++ b/kernel/irq/irqdomain.c
> > @@ -20,15 +20,15 @@ static DEFINE_MUTEX(irq_domain_mutex);
> >  void irq_domain_add(struct irq_domain *domain)
> >  {
> >  	struct irq_data *d;
> > -	int hwirq;
> > +	int hwirq, irq;
> >  
> >  	/*
> >  	 * This assumes that the irq_domain owner has already allocated
> >  	 * the irq_descs.  This block will be removed when support for dynamic
> >  	 * allocation of irq_descs is added to irq_domain.
> >  	 */
> > -	for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
> > -		d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
> > +	irq_domain_for_each_irq(domain, hwirq, irq) {
> > +		d = irq_get_irq_data(irq);
> >  		if (!d) {
> >  			WARN(1, "error: assigning domain to non existant irq_desc");
> >  			return;
> > @@ -54,15 +54,15 @@ void irq_domain_add(struct irq_domain *domain)
> >  void irq_domain_del(struct irq_domain *domain)
> >  {
> >  	struct irq_data *d;
> > -	int hwirq;
> > +	int hwirq, irq;
> >  
> >  	mutex_lock(&irq_domain_mutex);
> >  	list_del(&domain->list);
> >  	mutex_unlock(&irq_domain_mutex);
> >  
> >  	/* Clear the irq_domain assignments */
> > -	for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
> > -		d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
> > +	irq_domain_for_each_irq(domain, hwirq, irq) {
> > +		d = irq_get_irq_data(irq);
> >  		d->domain = NULL;
> >  	}
> >  }
>