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

From: Thomas Gleixner
Date: Sun Dec 12 2010 - 12:30:27 EST


On Sun, 12 Dec 2010, Jan Kiszka wrote:

> From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>
> 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@xxxxxxxxxxx>
> ---
> 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
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