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

[Derrick, Jonathan]

On Wed, 2020-08-26 at 21:42 +0100, Marc Zyngier wrote:
> 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.
> 

Acked-by: Jon Derrick <jonathan.derrick@xxxxxxxxx>