xen: events: maintain a list of Xen interrupts

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>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Ian Campbell 2011-03-10 16:08:11 +00:00 committed by Konrad Rzeszutek Wilk
parent 3d4cfa3736
commit 6cb6537d34

View File

@ -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);
}
static int xen_allocate_irq_dynamic(void)
{
int first = 0;
@ -426,6 +447,8 @@ static int xen_allocate_irq_dynamic(void)
if (irq < 0)
panic("No available IRQ to bind to: increase nr_irqs!\n");
xen_irq_init(irq);
return irq;
}
@ -444,18 +467,25 @@ static int xen_allocate_irq_gsi(unsigned gsi)
/* Legacy IRQ descriptors are already allocated by the arch. */
if (gsi < NR_IRQS_LEGACY)
return gsi;
irq = gsi;
else
irq = irq_alloc_desc_at(gsi, -1);
irq = irq_alloc_desc_at(gsi, -1);
if (irq < 0)
panic("Unable to allocate to IRQ%d (%d)\n", gsi, irq);
xen_irq_init(irq);
return irq;
}
static void xen_free_irq(unsigned irq)
{
irq_info[irq].type = IRQT_UNBOUND;
struct irq_info *info = &irq_info[irq];
info->type = IRQT_UNBOUND;
list_del(&info->list);
/* Legacy IRQ descriptors are managed by the arch. */
if (irq < NR_IRQS_LEGACY)
@ -586,16 +616,14 @@ static void ack_pirq(struct irq_data *data)
static int find_irq_by_gsi(unsigned gsi)
{
int irq;
struct irq_info *info;
for (irq = 0; irq < nr_irqs; irq++) {
struct irq_info *info = info_for_irq(irq);
if (info == NULL || info->type != IRQT_PIRQ)
list_for_each_entry(info, &xen_irq_list_head, list) {
if (info->type != IRQT_PIRQ)
continue;
if (gsi_from_irq(irq) == gsi)
return irq;
if (info->u.pirq.gsi == gsi)
return info->irq;
}
return -1;
@ -1374,7 +1402,8 @@ void xen_poll_irq(int irq)
void xen_irq_resume(void)
{
unsigned int cpu, irq, evtchn;
unsigned int cpu, evtchn;
struct irq_info *info;
init_evtchn_cpu_bindings();
@ -1383,8 +1412,8 @@ void xen_irq_resume(void)
mask_evtchn(evtchn);
/* No IRQ <-> event-channel mappings. */
for (irq = 0; irq < nr_irqs; irq++)
irq_info[irq].evtchn = 0; /* zap event-channel binding */
list_for_each_entry(info, &xen_irq_list_head, list)
info->evtchn = 0; /* zap event-channel binding */
for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
evtchn_to_irq[evtchn] = -1;