| Message ID | 1347621207-11294-16-git-send-email-stefano.stabellini@eu.citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 14/09/12 12:13, Stefano Stabellini wrote: > Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by > default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn't call > irq_startup, that is responsible for calling irq_unmask at startup time. > As a result event channels remain masked. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > drivers/xen/events.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/drivers/xen/events.c b/drivers/xen/events.c > index 5ecb596..8ffb7b7 100644 > --- a/drivers/xen/events.c > +++ b/drivers/xen/events.c > @@ -836,6 +836,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) > struct irq_info *info = info_for_irq(irq); > WARN_ON(info == NULL || info->type != IRQT_EVTCHN); > } > + irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN); This one just sent a shiver down my spine. Are you doing this for a PPI? M.
On Fri, 14 Sep 2012, Marc Zyngier wrote: > On 14/09/12 12:13, Stefano Stabellini wrote: > > Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by > > default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn't call > > irq_startup, that is responsible for calling irq_unmask at startup time. > > As a result event channels remain masked. > > > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > > --- > > drivers/xen/events.c | 1 + > > 1 files changed, 1 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/xen/events.c b/drivers/xen/events.c > > index 5ecb596..8ffb7b7 100644 > > --- a/drivers/xen/events.c > > +++ b/drivers/xen/events.c > > @@ -836,6 +836,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) > > struct irq_info *info = info_for_irq(irq); > > WARN_ON(info == NULL || info->type != IRQT_EVTCHN); > > } > > + irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN); > > This one just sent a shiver down my spine. Are you doing this for a PPI? Not really: even though there is just one source of event notifications (that is a PPI), we have many event channels. When a domain receives a notification (via the PPI), it checks on a bitmask to which event channel it corresponds. From the Linux point of view every event channel is a Linux irq belonging to the xen_dynamic_chip (see drivers/xen/events.c:xen_dynamic_chip). So here I am not doing this for the one PPI, but I am doing this for every Linux irq (of chip xen_dynamic_chip) that represents an event channel.
On 14/09/12 15:13, Stefano Stabellini wrote: > On Fri, 14 Sep 2012, Marc Zyngier wrote: >> On 14/09/12 12:13, Stefano Stabellini wrote: >>> Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by >>> default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn't call >>> irq_startup, that is responsible for calling irq_unmask at startup time. >>> As a result event channels remain masked. >>> >>> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> >>> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> >>> --- >>> drivers/xen/events.c | 1 + >>> 1 files changed, 1 insertions(+), 0 deletions(-) >>> >>> diff --git a/drivers/xen/events.c b/drivers/xen/events.c >>> index 5ecb596..8ffb7b7 100644 >>> --- a/drivers/xen/events.c >>> +++ b/drivers/xen/events.c >>> @@ -836,6 +836,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) >>> struct irq_info *info = info_for_irq(irq); >>> WARN_ON(info == NULL || info->type != IRQT_EVTCHN); >>> } >>> + irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN); >> >> This one just sent a shiver down my spine. Are you doing this for a PPI? > > Not really: even though there is just one source of event notifications > (that is a PPI), we have many event channels. When a domain receives a > notification (via the PPI), it checks on a bitmask to which event channel > it corresponds. From the Linux point of view every event channel is a > Linux irq belonging to the xen_dynamic_chip (see > drivers/xen/events.c:xen_dynamic_chip). > > So here I am not doing this for the one PPI, but I am doing this for > every Linux irq (of chip xen_dynamic_chip) that represents an event > channel. So this is some sort of secondary interrupt controller, cascaded into your GIC emulation, and this patch only affects the xen_dynamic_chip? M.
On Fri, 14 Sep 2012, Marc Zyngier wrote: > On 14/09/12 15:13, Stefano Stabellini wrote: > > On Fri, 14 Sep 2012, Marc Zyngier wrote: > >> On 14/09/12 12:13, Stefano Stabellini wrote: > >>> Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by > >>> default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn't call > >>> irq_startup, that is responsible for calling irq_unmask at startup time. > >>> As a result event channels remain masked. > >>> > >>> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > >>> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > >>> --- > >>> drivers/xen/events.c | 1 + > >>> 1 files changed, 1 insertions(+), 0 deletions(-) > >>> > >>> diff --git a/drivers/xen/events.c b/drivers/xen/events.c > >>> index 5ecb596..8ffb7b7 100644 > >>> --- a/drivers/xen/events.c > >>> +++ b/drivers/xen/events.c > >>> @@ -836,6 +836,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) > >>> struct irq_info *info = info_for_irq(irq); > >>> WARN_ON(info == NULL || info->type != IRQT_EVTCHN); > >>> } > >>> + irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN); > >> > >> This one just sent a shiver down my spine. Are you doing this for a PPI? > > > > Not really: even though there is just one source of event notifications > > (that is a PPI), we have many event channels. When a domain receives a > > notification (via the PPI), it checks on a bitmask to which event channel > > it corresponds. From the Linux point of view every event channel is a > > Linux irq belonging to the xen_dynamic_chip (see > > drivers/xen/events.c:xen_dynamic_chip). > > > > So here I am not doing this for the one PPI, but I am doing this for > > every Linux irq (of chip xen_dynamic_chip) that represents an event > > channel. > > So this is some sort of secondary interrupt controller, cascaded into > your GIC emulation, I guess it could be seen as a secondary interrupt controller > and this patch only affects the xen_dynamic_chip? Yep
On 14/09/12 15:28, Stefano Stabellini wrote: > On Fri, 14 Sep 2012, Marc Zyngier wrote: >> On 14/09/12 15:13, Stefano Stabellini wrote: >>> On Fri, 14 Sep 2012, Marc Zyngier wrote: >>>> On 14/09/12 12:13, Stefano Stabellini wrote: >>>>> Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by >>>>> default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn't call >>>>> irq_startup, that is responsible for calling irq_unmask at startup time. >>>>> As a result event channels remain masked. >>>>> >>>>> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> >>>>> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> >>>>> --- >>>>> drivers/xen/events.c | 1 + >>>>> 1 files changed, 1 insertions(+), 0 deletions(-) >>>>> >>>>> diff --git a/drivers/xen/events.c b/drivers/xen/events.c >>>>> index 5ecb596..8ffb7b7 100644 >>>>> --- a/drivers/xen/events.c >>>>> +++ b/drivers/xen/events.c >>>>> @@ -836,6 +836,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) >>>>> struct irq_info *info = info_for_irq(irq); >>>>> WARN_ON(info == NULL || info->type != IRQT_EVTCHN); >>>>> } >>>>> + irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN); >>>> >>>> This one just sent a shiver down my spine. Are you doing this for a PPI? >>> >>> Not really: even though there is just one source of event notifications >>> (that is a PPI), we have many event channels. When a domain receives a >>> notification (via the PPI), it checks on a bitmask to which event channel >>> it corresponds. From the Linux point of view every event channel is a >>> Linux irq belonging to the xen_dynamic_chip (see >>> drivers/xen/events.c:xen_dynamic_chip). >>> >>> So here I am not doing this for the one PPI, but I am doing this for >>> every Linux irq (of chip xen_dynamic_chip) that represents an event >>> channel. >> >> So this is some sort of secondary interrupt controller, cascaded into >> your GIC emulation, > > I guess it could be seen as a secondary interrupt controller > > >> and this patch only affects the xen_dynamic_chip? > > Yep Thanks. I feel relieved... ;-) M.
diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 5ecb596..8ffb7b7 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -836,6 +836,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) struct irq_info *info = info_for_irq(irq); WARN_ON(info == NULL || info->type != IRQT_EVTCHN); } + irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN); out: mutex_unlock(&irq_mapping_update_lock);