[patch 7/8] genirq: generic chip: Add linear irq domain support

[grant.likely@linaro.org (Grant Likely)]

On Mon, 06 May 2013 14:30:27 -0000, Thomas Gleixner <tglx@linutronix.de> wrote:
> Provide infrastructure for irq chip implementations which work on
> linear irq domains.
> 
> - Interface to allocate multiple generic chips which are associated to
>   the irq domain.
> 
> - Interface to get the generic chip pointer for a particular hardware
>   interrupt in the domain.
> 
> - irq domain mapping function to install the chip for a particular
>   interrupt.
> 
> Note: This lacks a removal function for now, but this is a draft patch
> the ARM folks to work on.
> 
> [ Sebastian Hesselbarth: Mask cache and pointer math fixups ]
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Hi Thomas,

Acked-by: Grant Likely <grant.likely@linaro.org>

But I have some comments below...

> ---
>  include/linux/irq.h       |   30 +++++++
>  include/linux/irqdomain.h |   12 ++
>  kernel/irq/generic-chip.c |  187 ++++++++++++++++++++++++++++++++++++++++++++--
>  kernel/irq/irqdomain.c    |    6 -
>  4 files changed, 223 insertions(+), 12 deletions(-)
> 
> Index: linux-2.6/include/linux/irq.h
> ===================================================================
> --- linux-2.6.orig/include/linux/irq.h
> +++ linux-2.6/include/linux/irq.h
> @@ -678,6 +678,8 @@ struct irq_chip_type {
>   * @wake_active:	Interrupt is marked as an wakeup from suspend source
>   * @num_ct:		Number of available irq_chip_type instances (usually 1)
>   * @private:		Private data for non generic chip callbacks
> + * @installed:		bitfield to denote installed interrupts
> + * @domain:		irq domain pointer
>   * @list:		List head for keeping track of instances
>   * @chip_types:		Array of interrupt irq_chip_types
>   *
> @@ -699,6 +701,8 @@ struct irq_chip_generic {
>  	u32			wake_active;
>  	unsigned int		num_ct;
>  	void			*private;
> +	unsigned long		installed;

This is probably something that the irqdomain should be keeping track of
internally, but that's an issue for a separate patch series.

[...]
> +struct irq_domain_ops irq_generic_chip_ops = {
> +	.map = irq_map_generic_chip,
> +	.xlate = irq_domain_xlate_onecell,

As discussed on IRC, should use onetwocell here for greater
compatibility with existing bindings.

Cheers,
g.