[PATCH v9 16/21] irqchip: Add GICv2 specific ACPI boot support

[rjw@rjwysocki.net (Rafael J. Wysocki)]

On Thursday, March 05, 2015 11:53:22 AM Catalin Marinas wrote:
> On Wed, Mar 04, 2015 at 11:50:36PM +0100, Rafael J. Wysocki wrote:
> > On Wednesday, February 25, 2015 04:39:56 PM Hanjun Guo wrote:

[cut]

> > > diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> > > index c03d8d1..e27117a 100644
> > > --- a/include/linux/acpi.h
> > > +++ b/include/linux/acpi.h
> > > @@ -557,6 +557,20 @@ static inline int acpi_device_modalias(struct device *dev,
> > >  
> > >  #endif	/* !CONFIG_ACPI */
> > >  
> > > +#if defined(CONFIG_ACPI) && defined(CONFIG_ARM64)
> > > +static inline void acpi_irq_init(void)
> > > +{
> > > +	/*
> > > +	 * Hardcode ACPI IRQ chip initialization to GICv2 for now.
> > > +	 * Proper irqchip infrastructure will be implemented along with
> > > +	 * incoming  GICv2m|GICv3|ITS bits.
> > > +	 */
> > > +	acpi_gic_init();
> > > +}
> > > +#else
> > > +static inline void acpi_irq_init(void) { }
> > > +#endif
> > 
> > I don't want this in a common header.
> 
> I don't like it either. What about adding it to a new header,
> linux/acpi_irq.h just for the dummy acpi_irq_init()? This would be
> similar to the DT equivalent, of_irq_init() in linux/of_irq.h and at
> some point it will gain more macros for declaring interrupt controllers
> in the ACPI context.
> 
> What we objected to previously was calling acpi_gic_init() directly from
> the core irqchip_init() and asked for something similar to the more
> generic of_irq_init(). The arm64-specific patch above is clearly a
> temporary hack until full support for multiple interrupt controllers is
> added (we asked for this several times in the past, but the ARM ACPI
> guys thought it's too much hassle ;). I don't fully get it since one of
> the platforms they target needs GICv2m support anyway).
> 
> Anyway, if we are to keep the temporary hack, I think we could define
> something like below (possibly in a new linux/acpi_irq.h which includes
> asm/irq.h):
> 
> #ifndef acpi_irq_init
> static inline void acpi_irq_init(void)
> {
> }
> #endif
> 
> And in the arm64 asm/irq.h:
> 
> static inline void acpi_irq_init(void)
> {
> 	/*
> 	 * Hardcode ACPI IRQ chip initialization to GICv2 for now.
> 	 * Proper irqchip infrastructure will be implemented along with
> 	 * incoming  GICv2m|GICv3|ITS bits.
> 	 */
> 	acpi_gic_init();
> }
> #define acpi_irq_init acpi_irq_init
> 
> When the new infrastructure is in place, we can get rid of the #ifndef
> and arm64-specific acpi_irq_init().

Well, that sounds much better than the original patch.

Rafael