lkml.org 
[lkml]   [2011]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [Xen-devel] [PATCH 10/14] xen: events: maintain a list of Xen interrupts
From
Date
On Thu, 2011-03-10 at 05:22 +0000, Konrad Rzeszutek Wilk wrote:
> On Wed, Mar 09, 2011 at 05:41:22PM +0000, Ian Campbell wrote:
> > In a PVHVM kernel not all interrupts are Xen interrupts (APIC interrupts can also be present).
> >
> > Currently we get away with walking over all interrupts because the
> > lookup in the irq_info array simply returns IRQT_UNBOUND and we ignore
> > it. However this array will be going away in a future patch so we need
> > to manually track which interrupts have been allocated by the Xen
> > events infrastructure.
> >
> > Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> > ---
> > drivers/xen/events.c | 59 +++++++++++++++++++++++++++++++++++++------------
> > 1 files changed, 44 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> > index cf372d4..e119989 100644
> > --- a/drivers/xen/events.c
> > +++ b/drivers/xen/events.c
> > @@ -56,6 +56,8 @@
> > */
> > static DEFINE_SPINLOCK(irq_mapping_update_lock);
> >
> > +static LIST_HEAD(xen_irq_list_head);
> > +
> > /* IRQ <-> VIRQ mapping. */
> > static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
> >
> > @@ -85,7 +87,9 @@ enum xen_irq_type {
> > */
> > struct irq_info
> > {
> > + struct list_head list;
> > enum xen_irq_type type; /* type */
> > + unsigned irq;
> > unsigned short evtchn; /* event channel */
> > unsigned short cpu; /* cpu bound */
> >
> > @@ -135,6 +139,7 @@ static void xen_irq_info_common_init(struct irq_info *info,
> > BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
> >
> > info->type = type;
> > + info->irq = irq;
> > info->evtchn = evtchn;
> > info->cpu = cpu;
> >
> > @@ -311,10 +316,11 @@ static void init_evtchn_cpu_bindings(void)
> > {
> > int i;
> > #ifdef CONFIG_SMP
> > - struct irq_desc *desc;
> > + struct irq_info *info;
> >
> > /* By default all event channels notify CPU#0. */
> > - for_each_irq_desc(i, desc) {
> > + list_for_each_entry(info, &xen_irq_list_head, list) {
> > + struct irq_desc *desc = irq_to_desc(info->irq);
> > cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
> > }
> > #endif
> > @@ -397,6 +403,21 @@ static void unmask_evtchn(int port)
> > put_cpu();
> > }
> >
> > +static void xen_irq_init(unsigned irq)
> > +{
> > + struct irq_info *info;
> > + struct irq_desc *desc = irq_to_desc(irq);
> > +
> > + /* By default all event channels notify CPU#0. */
> > + cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
> > +
> > + info = &irq_info[irq];
> > +
> > + info->type = IRQT_UNBOUND;
> > +
> > + list_add_tail(&info->list, &xen_irq_list_head);
>
> Should we use some form of spinlock lock? Just in case
> there are two drivers that are being unloaded?

The callers are xen_allocate_irq_dynamic and xen_allocate_irq_gsi both
of which expect to be protected by irq_mapping_update_lock already.



\
 
 \ /
  Last update: 2011-03-10 09:45    [W:0.072 / U:0.008 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site