aboutsummaryrefslogtreecommitdiff
path: root/drivers/xen/events/events_base.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/xen/events/events_base.c')
-rw-r--r--drivers/xen/events/events_base.c130
1 files changed, 100 insertions, 30 deletions
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index adb7260e94b2..7bbfd58958bc 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -98,13 +98,19 @@ struct irq_info {
short refcnt;
u8 spurious_cnt;
u8 is_accounted;
- enum xen_irq_type type; /* type */
+ short type; /* type: IRQT_* */
+ u8 mask_reason; /* Why is event channel masked */
+#define EVT_MASK_REASON_EXPLICIT 0x01
+#define EVT_MASK_REASON_TEMPORARY 0x02
+#define EVT_MASK_REASON_EOI_PENDING 0x04
+ u8 is_active; /* Is event just being handled? */
unsigned irq;
evtchn_port_t evtchn; /* event channel */
unsigned short cpu; /* cpu bound */
unsigned short eoi_cpu; /* EOI must happen on this cpu-1 */
unsigned int irq_epoch; /* If eoi_cpu valid: irq_epoch of event */
u64 eoi_time; /* Time in jiffies when to EOI. */
+ raw_spinlock_t lock;
union {
unsigned short virq;
@@ -154,6 +160,7 @@ static DEFINE_RWLOCK(evtchn_rwlock);
* evtchn_rwlock
* IRQ-desc lock
* percpu eoi_list_lock
+ * irq_info->lock
*/
static LIST_HEAD(xen_irq_list_head);
@@ -304,6 +311,8 @@ static int xen_irq_info_common_setup(struct irq_info *info,
info->irq = irq;
info->evtchn = evtchn;
info->cpu = cpu;
+ info->mask_reason = EVT_MASK_REASON_EXPLICIT;
+ raw_spin_lock_init(&info->lock);
ret = set_evtchn_to_irq(evtchn, irq);
if (ret < 0)
@@ -377,6 +386,7 @@ static int xen_irq_info_pirq_setup(unsigned irq,
static void xen_irq_info_cleanup(struct irq_info *info)
{
set_evtchn_to_irq(info->evtchn, -1);
+ xen_evtchn_port_remove(info->evtchn, info->cpu);
info->evtchn = 0;
channels_on_cpu_dec(info);
}
@@ -458,6 +468,34 @@ unsigned int cpu_from_evtchn(evtchn_port_t evtchn)
return ret;
}
+static void do_mask(struct irq_info *info, u8 reason)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&info->lock, flags);
+
+ if (!info->mask_reason)
+ mask_evtchn(info->evtchn);
+
+ info->mask_reason |= reason;
+
+ raw_spin_unlock_irqrestore(&info->lock, flags);
+}
+
+static void do_unmask(struct irq_info *info, u8 reason)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&info->lock, flags);
+
+ info->mask_reason &= ~reason;
+
+ if (!info->mask_reason)
+ unmask_evtchn(info->evtchn);
+
+ raw_spin_unlock_irqrestore(&info->lock, flags);
+}
+
#ifdef CONFIG_X86
static bool pirq_check_eoi_map(unsigned irq)
{
@@ -604,7 +642,7 @@ static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious)
}
info->eoi_time = 0;
- unmask_evtchn(evtchn);
+ do_unmask(info, EVT_MASK_REASON_EOI_PENDING);
}
static void xen_irq_lateeoi_worker(struct work_struct *work)
@@ -773,6 +811,12 @@ static void xen_evtchn_close(evtchn_port_t port)
BUG();
}
+static void event_handler_exit(struct irq_info *info)
+{
+ smp_store_release(&info->is_active, 0);
+ clear_evtchn(info->evtchn);
+}
+
static void pirq_query_unmask(int irq)
{
struct physdev_irq_status_query irq_status;
@@ -791,14 +835,15 @@ static void pirq_query_unmask(int irq)
static void eoi_pirq(struct irq_data *data)
{
- evtchn_port_t evtchn = evtchn_from_irq(data->irq);
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
int rc = 0;
if (!VALID_EVTCHN(evtchn))
return;
- clear_evtchn(evtchn);
+ event_handler_exit(info);
if (pirq_needs_eoi(data->irq)) {
rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
@@ -849,7 +894,8 @@ static unsigned int __startup_pirq(unsigned int irq)
goto err;
out:
- unmask_evtchn(evtchn);
+ do_unmask(info, EVT_MASK_REASON_EXPLICIT);
+
eoi_pirq(irq_get_irq_data(irq));
return 0;
@@ -876,7 +922,7 @@ static void shutdown_pirq(struct irq_data *data)
if (!VALID_EVTCHN(evtchn))
return;
- mask_evtchn(evtchn);
+ do_mask(info, EVT_MASK_REASON_EXPLICIT);
xen_evtchn_close(evtchn);
xen_irq_info_cleanup(info);
}
@@ -1628,6 +1674,8 @@ void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
}
info = info_for_irq(irq);
+ if (xchg_acquire(&info->is_active, 1))
+ return;
dev = (info->type == IRQT_EVTCHN) ? info->u.interdomain : NULL;
if (dev)
@@ -1720,10 +1768,10 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq)
}
/* Rebind an evtchn so that it gets delivered to a specific cpu */
-static int xen_rebind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int tcpu)
+static int xen_rebind_evtchn_to_cpu(struct irq_info *info, unsigned int tcpu)
{
struct evtchn_bind_vcpu bind_vcpu;
- int masked;
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
if (!VALID_EVTCHN(evtchn))
return -1;
@@ -1739,7 +1787,7 @@ static int xen_rebind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int tcpu)
* Mask the event while changing the VCPU binding to prevent
* it being delivered on an unexpected VCPU.
*/
- masked = test_and_set_mask(evtchn);
+ do_mask(info, EVT_MASK_REASON_TEMPORARY);
/*
* If this fails, it usually just indicates that we're dealing with a
@@ -1749,8 +1797,7 @@ static int xen_rebind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int tcpu)
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
bind_evtchn_to_cpu(evtchn, tcpu, false);
- if (!masked)
- unmask_evtchn(evtchn);
+ do_unmask(info, EVT_MASK_REASON_TEMPORARY);
return 0;
}
@@ -1789,7 +1836,7 @@ static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
unsigned int tcpu = select_target_cpu(dest);
int ret;
- ret = xen_rebind_evtchn_to_cpu(evtchn_from_irq(data->irq), tcpu);
+ ret = xen_rebind_evtchn_to_cpu(info_for_irq(data->irq), tcpu);
if (!ret)
irq_data_update_effective_affinity(data, cpumask_of(tcpu));
@@ -1798,28 +1845,29 @@ static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
static void enable_dynirq(struct irq_data *data)
{
- evtchn_port_t evtchn = evtchn_from_irq(data->irq);
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
if (VALID_EVTCHN(evtchn))
- unmask_evtchn(evtchn);
+ do_unmask(info, EVT_MASK_REASON_EXPLICIT);
}
static void disable_dynirq(struct irq_data *data)
{
- evtchn_port_t evtchn = evtchn_from_irq(data->irq);
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
if (VALID_EVTCHN(evtchn))
- mask_evtchn(evtchn);
+ do_mask(info, EVT_MASK_REASON_EXPLICIT);
}
static void ack_dynirq(struct irq_data *data)
{
- evtchn_port_t evtchn = evtchn_from_irq(data->irq);
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
- if (!VALID_EVTCHN(evtchn))
- return;
-
- clear_evtchn(evtchn);
+ if (VALID_EVTCHN(evtchn))
+ event_handler_exit(info);
}
static void mask_ack_dynirq(struct irq_data *data)
@@ -1828,18 +1876,39 @@ static void mask_ack_dynirq(struct irq_data *data)
ack_dynirq(data);
}
+static void lateeoi_ack_dynirq(struct irq_data *data)
+{
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (VALID_EVTCHN(evtchn)) {
+ do_mask(info, EVT_MASK_REASON_EOI_PENDING);
+ event_handler_exit(info);
+ }
+}
+
+static void lateeoi_mask_ack_dynirq(struct irq_data *data)
+{
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (VALID_EVTCHN(evtchn)) {
+ do_mask(info, EVT_MASK_REASON_EXPLICIT);
+ event_handler_exit(info);
+ }
+}
+
static int retrigger_dynirq(struct irq_data *data)
{
- evtchn_port_t evtchn = evtchn_from_irq(data->irq);
- int masked;
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
if (!VALID_EVTCHN(evtchn))
return 0;
- masked = test_and_set_mask(evtchn);
+ do_mask(info, EVT_MASK_REASON_TEMPORARY);
set_evtchn(evtchn);
- if (!masked)
- unmask_evtchn(evtchn);
+ do_unmask(info, EVT_MASK_REASON_TEMPORARY);
return 1;
}
@@ -1938,10 +2007,11 @@ static void restore_cpu_ipis(unsigned int cpu)
/* Clear an irq's pending state, in preparation for polling on it */
void xen_clear_irq_pending(int irq)
{
- evtchn_port_t evtchn = evtchn_from_irq(irq);
+ struct irq_info *info = info_for_irq(irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
if (VALID_EVTCHN(evtchn))
- clear_evtchn(evtchn);
+ event_handler_exit(info);
}
EXPORT_SYMBOL(xen_clear_irq_pending);
void xen_set_irq_pending(int irq)
@@ -2053,8 +2123,8 @@ static struct irq_chip xen_lateeoi_chip __read_mostly = {
.irq_mask = disable_dynirq,
.irq_unmask = enable_dynirq,
- .irq_ack = mask_ack_dynirq,
- .irq_mask_ack = mask_ack_dynirq,
+ .irq_ack = lateeoi_ack_dynirq,
+ .irq_mask_ack = lateeoi_mask_ack_dynirq,
.irq_set_affinity = set_affinity_irq,
.irq_retrigger = retrigger_dynirq,