[PATCH v2 1/3] arm/xen: Correctly check if the event channel interrupt is present

[Stefano Stabellini]

On Wed, 18 Feb 2015, Julien Grall wrote:
> The function irq_of_parse_and_map returns 0 when the IRQ is not found.
> 
> Futhermore, move the check before notifying the user that we are running on
> Xen.
> 
> Signed-off-by: Julien Grall <julien.grall at linaro.org>
> Acked-by: Ian Campbell <ian.campbell at citrix.com>

Acked-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>


> ---
>     Changes in v2:
>         - Add Ian's ack
>         - Re-add __read_mostly
> ---
>  arch/arm/xen/enlighten.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 263a204..c8d3a17 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -51,7 +51,7 @@ EXPORT_SYMBOL_GPL(xen_have_vector_callback);
>  int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
>  EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
>  
> -static __read_mostly int xen_events_irq = -1;
> +static __read_mostly unsigned int xen_events_irq;
>  
>  /* map fgmfn of domid to lpfn in the current domain */
>  static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn,
> @@ -251,12 +251,14 @@ static int __init xen_guest_init(void)
>  		return 0;
>  	grant_frames = res.start;
>  	xen_events_irq = irq_of_parse_and_map(node, 0);
> +	if (!xen_events_irq) {
> +		pr_debug("Xen event channel interrupt not found\n");
> +		return -ENODEV;
> +	}
> +
>  	pr_info("Xen %s support found, events_irq=%d gnttab_frame=%pa\n",
>  			version, xen_events_irq, &grant_frames);
>  
> -	if (xen_events_irq < 0)
> -		return -ENODEV;
> -
>  	xen_domain_type = XEN_HVM_DOMAIN;
>  
>  	xen_setup_features();
> -- 
> 2.1.4
>