Re: [patch V2 23/46] irqdomain/msi: Provide DOMAIN_BUS_VMD_MSI

[Marc Zyngier]

On Wed, 26 Aug 2020 12:16:51 +0100,
Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> 
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> 
> PCI devices behind a VMD bus are not subject to interrupt remapping, but
> the irq domain for VMD MSI cannot be distinguished from a regular PCI/MSI
> irq domain.
> 
> Add a new domain bus token and allow it in the bus token check in
> msi_check_reservation_mode() to keep the functionality the same once VMD
> uses this token.
> 
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> 
> ---
>  include/linux/irqdomain.h |    1 +
>  kernel/irq/msi.c          |    7 ++++++-
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -84,6 +84,7 @@ enum irq_domain_bus_token {
>  	DOMAIN_BUS_FSL_MC_MSI,
>  	DOMAIN_BUS_TI_SCI_INTA_MSI,
>  	DOMAIN_BUS_WAKEUP,
> +	DOMAIN_BUS_VMD_MSI,
>  };
>  
>  /**
> --- a/kernel/irq/msi.c
> +++ b/kernel/irq/msi.c
> @@ -370,8 +370,13 @@ static bool msi_check_reservation_mode(s
>  {
>  	struct msi_desc *desc;
>  
> -	if (domain->bus_token != DOMAIN_BUS_PCI_MSI)
> +	switch(domain->bus_token) {
> +	case DOMAIN_BUS_PCI_MSI:
> +	case DOMAIN_BUS_VMD_MSI:
> +		break;
> +	default:
>  		return false;
> +	}
>  
>  	if (!(info->flags & MSI_FLAG_MUST_REACTIVATE))
>  		return false;

Acked-by: Marc Zyngier <maz@xxxxxxxxxx>

	M.

-- 
Without deviation from the norm, progress is not possible.