Re: [Xen-devel] [PATCH v3 07/10] xen/arm: Release maintenance interrupt when CPU is hot-unplugged

[Julien Grall <julien.grall@xxxxxxx>]

Hi Mirela,

On 27/04/18 18:12, Mirela Simonovic wrote:
> When a CPU is hot-unplugged the maintenance interrupt has to be
> released in order to free the memory that was allocated when the CPU
> was hotplugged and interrupt requested. The interrupt was requested
> using request_irq() which is called from start_secondary->
> init_maintenance_interrupt. With this patch the interrupt will be
> released when the CPU_DYING event is received by the callback which
> is added in gic.c.
>
> Signed-off-by: Mirela Simonovic <mirela.simonovic@xxxxxxxxxx>
>
> ---
> CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> CC: Julien Grall <julien.grall@xxxxxxx>
> ---
> Changes in v3:
> -Add notifier in order to trigger releasing of the  maintenance
>   interrupt when the CPU is dying.
> ---
>   xen/arch/arm/gic.c | 29 +++++++++++++++++++++++++++++
>   1 file changed, 29 insertions(+)
>
> diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
> index 653a815127..89abc49950 100644
> --- a/xen/arch/arm/gic.c
> +++ b/xen/arch/arm/gic.c
> @@ -27,6 +27,8 @@
>   #include <xen/list.h>
>   #include <xen/device_tree.h>
>   #include <xen/acpi.h>
> +#include <xen/notifier.h>
> +#include <xen/cpu.h>
>   #include <asm/p2m.h>
>   #include <asm/domain.h>
>   #include <asm/platform.h>
> @@ -462,6 +464,33 @@ int gic_iomem_deny_access(const struct domain *d)
>       return gic_hw_ops->iomem_deny_access(d);
>   }
>   
> +static int cpu_gic_callback(
> +    struct notifier_block *nfb, unsigned long action, void *hcpu)
Please fix the indentation.

With that:

Acked-by: Julien Grall <julien.grall@xxxxxxx>

> +{
> +    switch ( action )
> +    {
> +    case CPU_DYING:
> +        /* This is reverting the work done in init_maintenance_interrupt */
In the future we probably want to move init_maintenance_interrupt in the 
notifier. But that's a clean-up after this has been merged :).
> +        release_irq(gic_hw_ops->info->maintenance_irq, NULL);
> +        break;
> +    default:
> +        break;
> +    }
> +
> +    return NOTIFY_DONE;
> +}
> +
> +static struct notifier_block cpu_gic_nfb = {
> +    .notifier_call = cpu_gic_callback,
> +};
> +
> +static int __init cpu_gic_notifier_init(void)
> +{
> +    register_cpu_notifier(&cpu_gic_nfb);
> +    return 0;
> +}
> +__initcall(cpu_gic_notifier_init);
> +
>   /*
>    * Local variables:
>    * mode: C
Cheers,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel