diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 6f02c18..cc31773 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -33,6 +33,10 @@
#include <linux/slab.h>
#include <linux/irqnr.h>
#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/cpuhotplug.h>
+#include <linux/atomic.h>
+#include <linux/ktime.h>
#ifdef CONFIG_X86
#include <asm/desc.h>
@@ -63,6 +67,15 @@
#include "events_internal.h"
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "xen."
+
+static uint __read_mostly event_loop_timeout = 2;
+module_param(event_loop_timeout, uint, 0644);
+
+static uint __read_mostly event_eoi_delay = 10;
+module_param(event_eoi_delay, uint, 0644);
+
const struct evtchn_ops *evtchn_ops;
/*
@@ -71,6 +84,24 @@ const struct evtchn_ops *evtchn_ops;
*/
static DEFINE_MUTEX(irq_mapping_update_lock);
+/*
+ * Lock protecting event handling loop against removing event channels.
+ * Adding of event channels is no issue as the associated IRQ becomes active
+ * only after everything is setup (before request_[threaded_]irq() the handler
+ * can't be entered for an event, as the event channel will be unmasked only
+ * then).
+ */
+static DEFINE_RWLOCK(evtchn_rwlock);
+
+/*
+ * Lock hierarchy:
+ *
+ * irq_mapping_update_lock
+ * evtchn_rwlock
+ * IRQ-desc lock
+ * percpu eoi_list_lock
+ */
+
static LIST_HEAD(xen_irq_list_head);
/* IRQ <-> VIRQ mapping. */
@@ -95,17 +126,20 @@ static bool (*pirq_needs_eoi)(unsigned irq);
static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY];
static struct irq_chip xen_dynamic_chip;
+static struct irq_chip xen_lateeoi_chip;
static struct irq_chip xen_percpu_chip;
static struct irq_chip xen_pirq_chip;
static void enable_dynirq(struct irq_data *data);
static void disable_dynirq(struct irq_data *data);
+static DEFINE_PER_CPU(unsigned int, irq_epoch);
+
static void clear_evtchn_to_irq_row(unsigned row)
{
unsigned col;
for (col = 0; col < EVTCHN_PER_ROW; col++)
- evtchn_to_irq[row][col] = -1;
+ WRITE_ONCE(evtchn_to_irq[row][col], -1);
}
static void clear_evtchn_to_irq_all(void)
@@ -142,7 +176,7 @@ static int set_evtchn_to_irq(evtchn_port_t evtchn, unsigned int irq)
clear_evtchn_to_irq_row(row);
}
- evtchn_to_irq[row][col] = irq;
+ WRITE_ONCE(evtchn_to_irq[row][col], irq);
return 0;
}
@@ -152,7 +186,7 @@ int get_evtchn_to_irq(evtchn_port_t evtchn)
return -1;
if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
return -1;
- return evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)];
+ return READ_ONCE(evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)]);
}
/* Get info for IRQ */
@@ -261,10 +295,14 @@ static void xen_irq_info_cleanup(struct irq_info *info)
*/
evtchn_port_t evtchn_from_irq(unsigned irq)
{
- if (WARN(irq >= nr_irqs, "Invalid irq %d!\n", irq))
+ const struct irq_info *info = NULL;
+
+ if (likely(irq < nr_irqs))
+ info = info_for_irq(irq);
+ if (!info)
return 0;
- return info_for_irq(irq)->evtchn;
+ return info->evtchn;
}
unsigned int irq_from_evtchn(evtchn_port_t evtchn)
@@ -375,9 +413,157 @@ void notify_remote_via_irq(int irq)
}
EXPORT_SYMBOL_GPL(notify_remote_via_irq);
+struct lateeoi_work {
+ struct delayed_work delayed;
+ spinlock_t eoi_list_lock;
+ struct list_head eoi_list;
+};
+
+static DEFINE_PER_CPU(struct lateeoi_work, lateeoi);
+
+static void lateeoi_list_del(struct irq_info *info)
+{
+ struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu);
+ unsigned long flags;
+
+ spin_lock_irqsave(&eoi->eoi_list_lock, flags);
+ list_del_init(&info->eoi_list);
+ spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
+}
+
+static void lateeoi_list_add(struct irq_info *info)
+{
+ struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu);
+ struct irq_info *elem;
+ u64 now = get_jiffies_64();
+ unsigned long delay;
+ unsigned long flags;
+
+ if (now < info->eoi_time)
+ delay = info->eoi_time - now;
+ else
+ delay = 1;
+
+ spin_lock_irqsave(&eoi->eoi_list_lock, flags);
+
+ if (list_empty(&eoi->eoi_list)) {
+ list_add(&info->eoi_list, &eoi->eoi_list);
+ mod_delayed_work_on(info->eoi_cpu, system_wq,
+ &eoi->delayed, delay);
+ } else {
+ list_for_each_entry_reverse(elem, &eoi->eoi_list, eoi_list) {
+ if (elem->eoi_time <= info->eoi_time)
+ break;
+ }
+ list_add(&info->eoi_list, &elem->eoi_list);
+ }
+
+ spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
+}
+
+static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious)
+{
+ evtchn_port_t evtchn;
+ unsigned int cpu;
+ unsigned int delay = 0;
+
+ evtchn = info->evtchn;
+ if (!VALID_EVTCHN(evtchn) || !list_empty(&info->eoi_list))
+ return;
+
+ if (spurious) {
+ if ((1 << info->spurious_cnt) < (HZ << 2))
+ info->spurious_cnt++;
+ if (info->spurious_cnt > 1) {
+ delay = 1 << (info->spurious_cnt - 2);
+ if (delay > HZ)
+ delay = HZ;
+ if (!info->eoi_time)
+ info->eoi_cpu = smp_processor_id();
+ info->eoi_time = get_jiffies_64() + delay;
+ }
+ } else {
+ info->spurious_cnt = 0;
+ }
+
+ cpu = info->eoi_cpu;
+ if (info->eoi_time &&
+ (info->irq_epoch == per_cpu(irq_epoch, cpu) || delay)) {
+ lateeoi_list_add(info);
+ return;
+ }
+
+ info->eoi_time = 0;
+ unmask_evtchn(evtchn);
+}
+
+static void xen_irq_lateeoi_worker(struct work_struct *work)
+{
+ struct lateeoi_work *eoi;
+ struct irq_info *info;
+ u64 now = get_jiffies_64();
+ unsigned long flags;
+
+ eoi = container_of(to_delayed_work(work), struct lateeoi_work, delayed);
+
+ read_lock_irqsave(&evtchn_rwlock, flags);
+
+ while (true) {
+ spin_lock(&eoi->eoi_list_lock);
+
+ info = list_first_entry_or_null(&eoi->eoi_list, struct irq_info,
+ eoi_list);
+
+ if (info == NULL || now < info->eoi_time) {
+ spin_unlock(&eoi->eoi_list_lock);
+ break;