Re: [PATCH v2 1/4] genirq: Introduce driver-readable IRQ status word

[Thomas Gleixner <tglx@linutronix.de>]

On Sun, 12 Dec 2010, Jan Kiszka wrote:

> From: Jan Kiszka <jan.kiszka@siemens.com>
> 
> This associates a status word with every IRQ descriptor. Drivers can obtain
> its content via get_irq_status(irq). First use case will be propagating the
> interrupt sharing state.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  include/linux/interrupt.h |    2 ++
>  include/linux/irq.h       |    2 ++
>  kernel/irq/manage.c       |   15 +++++++++++++++
>  3 files changed, 19 insertions(+), 0 deletions(-)
> 
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 79d0c4f..16cdbbf 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -126,6 +126,8 @@ struct irqaction {
>  
>  extern irqreturn_t no_action(int cpl, void *dev_id);
>  
> +extern unsigned long get_irq_status(unsigned long irq);
> +
>  #ifdef CONFIG_GENERIC_HARDIRQS
>  extern int __must_check
>  request_threaded_irq(unsigned int irq, irq_handler_t handler,
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index abde252..5554203 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -96,6 +96,7 @@ struct msi_desc;
>   *			methods, to allow shared chip implementations
>   * @msi_desc:		MSI descriptor
>   * @affinity:		IRQ affinity on SMP
> + * @status:		driver-readable status flags (IRQS_*)
>   *
>   * The fields here need to overlay the ones in irq_desc until we
>   * cleaned up the direct references and switched everything over to
> @@ -108,6 +109,7 @@ struct irq_data {
>  	void			*handler_data;
>  	void			*chip_data;
>  	struct msi_desc		*msi_desc;
> +	unsigned long		status;

That breaks the current code which has irq_data embedded and shadowed
in irq_desc for migratory reasons until all users are fixed up and the
GENERIC_HARDIRQS_NO_DEPRECATED sections are cleaned up. I know it's
ugly, but that was the only way not to rewrite the world in one go. :)
Just move it below affinity.

Also we should name it different than status, drv_status perhaps, to
avoid confusion with the irq_desc status.

>  #ifdef CONFIG_SMP
>  	cpumask_var_t		affinity;
>  #endif

Thanks,

	tglx