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-rw-r--r--drivers/xen/events/events_2l.c9
-rw-r--r--drivers/xen/events/events_base.c423
-rw-r--r--drivers/xen/events/events_fifo.c83
-rw-r--r--drivers/xen/events/events_internal.h20
4 files changed, 455 insertions, 80 deletions
diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c
index 64df919a2111..fe5ad0e89cd8 100644
--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -91,6 +91,8 @@ static void evtchn_2l_unmask(evtchn_port_t port)
BUG_ON(!irqs_disabled());
+ smp_wmb(); /* All writes before unmask must be visible. */
+
if (unlikely((cpu != cpu_from_evtchn(port))))
do_hypercall = 1;
else {
@@ -159,7 +161,7 @@ static inline xen_ulong_t active_evtchns(unsigned int cpu,
* a bitset of words which contain pending event bits. The second
* level is a bitset of pending events themselves.
*/
-static void evtchn_2l_handle_events(unsigned cpu)
+static void evtchn_2l_handle_events(unsigned cpu, struct evtchn_loop_ctrl *ctrl)
{
int irq;
xen_ulong_t pending_words;
@@ -240,10 +242,7 @@ static void evtchn_2l_handle_events(unsigned cpu)
/* Process port. */
port = (word_idx * BITS_PER_EVTCHN_WORD) + bit_idx;
- irq = get_evtchn_to_irq(port);
-
- if (irq != -1)
- generic_handle_irq(irq);
+ handle_irq_for_port(port, ctrl);
bit_idx = (bit_idx + 1) % BITS_PER_EVTCHN_WORD;
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 6f02c18fa65c..cc317739e786 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;
+ }
+
+ list_del_init(&info->eoi_list);
+
+ spin_unlock(&eoi->eoi_list_lock);
+
+ info->eoi_time = 0;
+
+ xen_irq_lateeoi_locked(info, false);
+ }
+
+ if (info)
+ mod_delayed_work_on(info->eoi_cpu, system_wq,
+ &eoi->delayed, info->eoi_time - now);
+
+ read_unlock_irqrestore(&evtchn_rwlock, flags);
+}
+
+static void xen_cpu_init_eoi(unsigned int cpu)
+{
+ struct lateeoi_work *eoi = &per_cpu(lateeoi, cpu);
+
+ INIT_DELAYED_WORK(&eoi->delayed, xen_irq_lateeoi_worker);
+ spin_lock_init(&eoi->eoi_list_lock);
+ INIT_LIST_HEAD(&eoi->eoi_list);
+}
+
+void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags)
+{
+ struct irq_info *info;
+ unsigned long flags;
+
+ read_lock_irqsave(&evtchn_rwlock, flags);
+
+ info = info_for_irq(irq);
+
+ if (info)
+ xen_irq_lateeoi_locked(info, eoi_flags & XEN_EOI_FLAG_SPURIOUS);
+
+ read_unlock_irqrestore(&evtchn_rwlock, flags);
+}
+EXPORT_SYMBOL_GPL(xen_irq_lateeoi);
+
static void xen_irq_init(unsigned irq)
{
struct irq_info *info;
+
#ifdef CONFIG_SMP
/* By default all event channels notify CPU#0. */
cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(0));
@@ -392,6 +578,7 @@ static void xen_irq_init(unsigned irq)
set_info_for_irq(irq, info);
+ INIT_LIST_HEAD(&info->eoi_list);
list_add_tail(&info->list, &xen_irq_list_head);
}
@@ -440,16 +627,24 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi)
static void xen_free_irq(unsigned irq)
{
struct irq_info *info = info_for_irq(irq);
+ unsigned long flags;
if (WARN_ON(!info))
return;
+ write_lock_irqsave(&evtchn_rwlock, flags);
+
+ if (!list_empty(&info->eoi_list))
+ lateeoi_list_del(info);
+
list_del(&info->list);
set_info_for_irq(irq, NULL);
WARN_ON(info->refcnt > 0);
+ write_unlock_irqrestore(&evtchn_rwlock, flags);
+
kfree(info);
/* Legacy IRQ descriptors are managed by the arch. */
@@ -841,7 +1036,7 @@ int xen_pirq_from_irq(unsigned irq)
}
EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
-int bind_evtchn_to_irq(evtchn_port_t evtchn)
+static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip)
{
int irq;
int ret;
@@ -858,7 +1053,7 @@ int bind_evtchn_to_irq(evtchn_port_t evtchn)
if (irq < 0)
goto out;
- irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
+ irq_set_chip_and_handler_name(irq, chip,
handle_edge_irq, "event");
ret = xen_irq_info_evtchn_setup(irq, evtchn);
@@ -879,8 +1074,19 @@ out:
return irq;
}
+
+int bind_evtchn_to_irq(evtchn_port_t evtchn)
+{
+ return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip);
+}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
+int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn)
+{
+ return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi);
+
static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
{
struct evtchn_bind_ipi bind_ipi;
@@ -922,8 +1128,9 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
return irq;
}
-int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
- evtchn_port_t remote_port)
+static int bind_interdomain_evtchn_to_irq_chip(unsigned int remote_domain,
+ evtchn_port_t remote_port,
+ struct irq_chip *chip)
{
struct evtchn_bind_interdomain bind_interdomain;
int err;
@@ -934,10 +1141,26 @@ int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
&bind_interdomain);
- return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
+ return err ? : bind_evtchn_to_irq_chip(bind_interdomain.local_port,
+ chip);
+}
+
+int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
+ evtchn_port_t remote_port)
+{
+ return bind_interdomain_evtchn_to_irq_chip(remote_domain, remote_port,
+ &xen_dynamic_chip);
}
EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq);
+int bind_interdomain_evtchn_to_irq_lateeoi(unsigned int remote_domain,
+ evtchn_port_t remote_port)
+{
+ return bind_interdomain_evtchn_to_irq_chip(remote_domain, remote_port,
+ &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq_lateeoi);
+
static int find_virq(unsigned int virq, unsigned int cpu, evtchn_port_t *evtchn)
{
struct evtchn_status status;
@@ -1034,14 +1257,15 @@ static void unbind_from_irq(unsigned int irq)
mutex_unlock(&irq_mapping_update_lock);
}
-int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
- irq_handler_t handler,
- unsigned long irqflags,
- const char *devname, void *dev_id)
+static int bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname, void *dev_id,
+ struct irq_chip *chip)
{
int irq, retval;
- irq = bind_evtchn_to_irq(evtchn);
+ irq = bind_evtchn_to_irq_chip(evtchn, chip);
if (irq < 0)
return irq;
retval = request_irq(irq, handler, irqflags, devname, dev_id);
@@ -1052,18 +1276,38 @@ int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
return irq;
}
+
+int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname, void *dev_id)
+{
+ return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
+ devname, dev_id,
+ &xen_dynamic_chip);
+}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
-int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
- evtchn_port_t remote_port,
- irq_handler_t handler,
- unsigned long irqflags,
- const char *devname,
- void *dev_id)
+int bind_evtchn_to_irqhandler_lateeoi(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname, void *dev_id)
+{
+ return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
+ devname, dev_id,
+ &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler_lateeoi);
+
+static int bind_interdomain_evtchn_to_irqhandler_chip(
+ unsigned int remote_domain, evtchn_port_t remote_port,
+ irq_handler_t handler, unsigned long irqflags,
+ const char *devname, void *dev_id, struct irq_chip *chip)
{
int irq, retval;
- irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
+ irq = bind_interdomain_evtchn_to_irq_chip(remote_domain, remote_port,
+ chip);
if (irq < 0)
return irq;
@@ -1075,8 +1319,33 @@ int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
return irq;
}
+
+int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
+ evtchn_port_t remote_port,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname,
+ void *dev_id)
+{
+ return bind_interdomain_evtchn_to_irqhandler_chip(remote_domain,
+ remote_port, handler, irqflags, devname,
+ dev_id, &xen_dynamic_chip);
+}
EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
+int bind_interdomain_evtchn_to_irqhandler_lateeoi(unsigned int remote_domain,
+ evtchn_port_t remote_port,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname,
+ void *dev_id)
+{
+ return bind_interdomain_evtchn_to_irqhandler_chip(remote_domain,
+ remote_port, handler, irqflags, devname,
+ dev_id, &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler_lateeoi);
+
int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
irq_handler_t handler,
unsigned long irqflags, const char *devname, void *dev_id)
@@ -1189,7 +1458,7 @@ int evtchn_get(evtchn_port_t evtchn)
goto done;
err = -EINVAL;
- if (info->refcnt <= 0)
+ if (info->refcnt <= 0 || info->refcnt == SHRT_MAX)
goto done;
info->refcnt++;
@@ -1228,21 +1497,81 @@ void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
notify_remote_via_irq(irq);
}
+struct evtchn_loop_ctrl {
+ ktime_t timeout;
+ unsigned count;
+ bool defer_eoi;
+};
+
+void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
+{
+ int irq;
+ struct irq_info *info;
+
+ irq = get_evtchn_to_irq(port);
+ if (irq == -1)
+ return;
+
+ /*
+ * Check for timeout every 256 events.
+ * We are setting the timeout value only after the first 256
+ * events in order to not hurt the common case of few loop
+ * iterations. The 256 is basically an arbitrary value.
+ *
+ * In case we are hitting the timeout we need to defer all further
+ * EOIs in order to ensure to leave the event handling loop rather
+ * sooner than later.
+ */
+ if (!ctrl->defer_eoi && !(++ctrl->count & 0xff)) {
+ ktime_t kt = ktime_get();
+
+ if (!ctrl->timeout) {
+ kt = ktime_add_ms(kt,
+ jiffies_to_msecs(event_loop_timeout));
+ ctrl->timeout = kt;
+ } else if (kt > ctrl->timeout) {
+ ctrl->defer_eoi = true;
+ }
+ }
+
+ info = info_for_irq(irq);
+
+ if (ctrl->defer_eoi) {
+ info->eoi_cpu = smp_processor_id();
+ info->irq_epoch = __this_cpu_read(irq_epoch);
+ info->eoi_time = get_jiffies_64() + event_eoi_delay;
+ }
+
+ generic_handle_irq(irq);
+}
+
static void __xen_evtchn_do_upcall(void)
{
struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
int cpu = smp_processor_id();
+ struct evtchn_loop_ctrl ctrl = { 0 };
+
+ read_lock(&evtchn_rwlock);
do {
vcpu_info->evtchn_upcall_pending = 0;
- xen_evtchn_handle_events(cpu);
+ xen_evtchn_handle_events(cpu, &ctrl);
BUG_ON(!irqs_disabled());
virt_rmb(); /* Hypervisor can set upcall pending. */
} while (vcpu_info->evtchn_upcall_pending);
+
+ read_unlock(&evtchn_rwlock);
+
+ /*
+ * Increment irq_epoch only now to defer EOIs only for
+ * xen_irq_lateeoi() invocations occurring from inside the loop
+ * above.
+ */
+ __this_cpu_inc(irq_epoch);
}
void xen_evtchn_do_upcall(struct pt_regs *regs)
@@ -1606,6 +1935,21 @@ static struct irq_chip xen_dynamic_chip __read_mostly = {
.irq_retrigger = retrigger_dynirq,
};
+static struct irq_chip xen_lateeoi_chip __read_mostly = {
+ /* The chip name needs to contain "xen-dyn" for irqbalance to work. */
+ .name = "xen-dyn-lateeoi",
+
+ .irq_disable = disable_dynirq,
+ .irq_mask = disable_dynirq,
+ .irq_unmask = enable_dynirq,
+
+ .irq_ack = mask_ack_dynirq,
+ .irq_mask_ack = mask_ack_dynirq,
+
+ .irq_set_affinity = set_affinity_irq,
+ .irq_retrigger = retrigger_dynirq,
+};
+
static struct irq_chip xen_pirq_chip __read_mostly = {
.name = "xen-pirq",
@@ -1676,12 +2020,31 @@ void xen_setup_callback_vector(void) {}
static inline void xen_alloc_callback_vector(void) {}
#endif
-#undef MODULE_PARAM_PREFIX
-#define MODULE_PARAM_PREFIX "xen."
-
static bool fifo_events = true;
module_param(fifo_events, bool, 0);
+static int xen_evtchn_cpu_prepare(unsigned int cpu)
+{
+ int ret = 0;
+
+ xen_cpu_init_eoi(cpu);
+
+ if (evtchn_ops->percpu_init)
+ ret = evtchn_ops->percpu_init(cpu);
+
+ return ret;
+}
+
+static int xen_evtchn_cpu_dead(unsigned int cpu)
+{
+ int ret = 0;
+
+ if (evtchn_ops->percpu_deinit)
+ ret = evtchn_ops->percpu_deinit(cpu);
+
+ return ret;
+}
+
void __init xen_init_IRQ(void)
{
int ret = -EINVAL;
@@ -1692,6 +2055,12 @@ void __init xen_init_IRQ(void)
if (ret < 0)
xen_evtchn_2l_init();
+ xen_cpu_init_eoi(smp_processor_id());
+
+ cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
+ "xen/evtchn:prepare",
+ xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
+
evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
sizeof(*evtchn_to_irq), GFP_KERNEL);
BUG_ON(!evtchn_to_irq);
diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c
index c60ee0450173..6085a808da95 100644
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -227,19 +227,25 @@ static bool evtchn_fifo_is_masked(evtchn_port_t port)
return sync_test_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
}
/*
- * Clear MASKED, spinning if BUSY is set.
+ * Clear MASKED if not PENDING, spinning if BUSY is set.
+ * Return true if mask was cleared.
*/
-static void clear_masked(volatile event_word_t *word)
+static bool clear_masked_cond(volatile event_word_t *word)
{
event_word_t new, old, w;
w = *word;
do {
+ if (w & (1 << EVTCHN_FIFO_PENDING))
+ return false;
+
old = w & ~(1 << EVTCHN_FIFO_BUSY);
new = old & ~(1 << EVTCHN_FIFO_MASKED);
w = sync_cmpxchg(word, old, new);
} while (w != old);
+
+ return true;
}
static void evtchn_fifo_unmask(evtchn_port_t port)
@@ -248,8 +254,7 @@ static void evtchn_fifo_unmask(evtchn_port_t port)
BUG_ON(!irqs_disabled());
- clear_masked(word);
- if (evtchn_fifo_is_pending(port)) {
+ if (!clear_masked_cond(word)) {
struct evtchn_unmask unmask = { .port = port };
(void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
}
@@ -270,19 +275,9 @@ static uint32_t clear_linked(volatile event_word_t *word)
return w & EVTCHN_FIFO_LINK_MASK;
}
-static void handle_irq_for_port(evtchn_port_t port)
-{
- int irq;
-
- irq = get_evtchn_to_irq(port);
- if (irq != -1)
- generic_handle_irq(irq);
-}
-
-static void consume_one_event(unsigned cpu,
+static void consume_one_event(unsigned cpu, struct evtchn_loop_ctrl *ctrl,
struct evtchn_fifo_control_block *control_block,
- unsigned priority, unsigned long *ready,
- bool drop)
+ unsigned priority, unsigned long *ready)
{
struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu);
uint32_t head;
@@ -315,16 +310,17 @@ static void consume_one_event(unsigned cpu,
clear_bit(priority, ready);
if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port)) {
- if (unlikely(drop))
+ if (unlikely(!ctrl))
pr_warn("Dropping pending event for port %u\n", port);
else
- handle_irq_for_port(port);
+ handle_irq_for_port(port, ctrl);
}
q->head[priority] = head;
}
-static void __evtchn_fifo_handle_events(unsigned cpu, bool drop)
+static void __evtchn_fifo_handle_events(unsigned cpu,
+ struct evtchn_loop_ctrl *ctrl)
{
struct evtchn_fifo_control_block *control_block;
unsigned long ready;
@@ -336,14 +332,15 @@ static void __evtchn_fifo_handle_events(unsigned cpu, bool drop)
while (ready) {
q = find_first_bit(&ready, EVTCHN_FIFO_MAX_QUEUES);
- consume_one_event(cpu, control_block, q, &ready, drop);
+ consume_one_event(cpu, ctrl, control_block, q, &ready);
ready |= xchg(&control_block->ready, 0);
}
}
-static void evtchn_fifo_handle_events(unsigned cpu)
+static void evtchn_fifo_handle_events(unsigned cpu,
+ struct evtchn_loop_ctrl *ctrl)
{
- __evtchn_fifo_handle_events(cpu, false);
+ __evtchn_fifo_handle_events(cpu, ctrl);
}
static void evtchn_fifo_resume(void)
@@ -380,21 +377,6 @@ static void evtchn_fifo_resume(void)
event_array_pages = 0;
}
-static const struct evtchn_ops evtchn_ops_fifo = {
- .max_channels = evtchn_fifo_max_channels,
- .nr_channels = evtchn_fifo_nr_channels,
- .setup = evtchn_fifo_setup,
- .bind_to_cpu = evtchn_fifo_bind_to_cpu,
- .clear_pending = evtchn_fifo_clear_pending,
- .set_pending = evtchn_fifo_set_pending,
- .is_pending = evtchn_fifo_is_pending,
- .test_and_set_mask = evtchn_fifo_test_and_set_mask,
- .mask = evtchn_fifo_mask,
- .unmask = evtchn_fifo_unmask,
- .handle_events = evtchn_fifo_handle_events,
- .resume = evtchn_fifo_resume,
-};
-
static int evtchn_fifo_alloc_control_block(unsigned cpu)
{
void *control_block = NULL;
@@ -417,19 +399,36 @@ static int evtchn_fifo_alloc_control_block(unsigned cpu)
return ret;
}
-static int xen_evtchn_cpu_prepare(unsigned int cpu)
+static int evtchn_fifo_percpu_init(unsigned int cpu)
{
if (!per_cpu(cpu_control_block, cpu))
return evtchn_fifo_alloc_control_block(cpu);
return 0;
}
-static int xen_evtchn_cpu_dead(unsigned int cpu)
+static int evtchn_fifo_percpu_deinit(unsigned int cpu)
{
- __evtchn_fifo_handle_events(cpu, true);
+ __evtchn_fifo_handle_events(cpu, NULL);
return 0;
}
+static const struct evtchn_ops evtchn_ops_fifo = {
+ .max_channels = evtchn_fifo_max_channels,
+ .nr_channels = evtchn_fifo_nr_channels,
+ .setup = evtchn_fifo_setup,
+ .bind_to_cpu = evtchn_fifo_bind_to_cpu,
+ .clear_pending = evtchn_fifo_clear_pending,
+ .set_pending = evtchn_fifo_set_pending,
+ .is_pending = evtchn_fifo_is_pending,
+ .test_and_set_mask = evtchn_fifo_test_and_set_mask,
+ .mask = evtchn_fifo_mask,
+ .unmask = evtchn_fifo_unmask,
+ .handle_events = evtchn_fifo_handle_events,
+ .resume = evtchn_fifo_resume,
+ .percpu_init = evtchn_fifo_percpu_init,
+ .percpu_deinit = evtchn_fifo_percpu_deinit,
+};
+
int __init xen_evtchn_fifo_init(void)
{
int cpu = smp_processor_id();
@@ -443,9 +442,5 @@ int __init xen_evtchn_fifo_init(void)
evtchn_ops = &evtchn_ops_fifo;
- cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
- "xen/evtchn:prepare",
- xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
-
return ret;
}
diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h
index 10684feb094e..82937d90d7d7 100644
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -30,11 +30,16 @@ enum xen_irq_type {
*/
struct irq_info {
struct list_head list;
- int refcnt;
+ struct list_head eoi_list;
+ short refcnt;
+ short spurious_cnt;
enum xen_irq_type type; /* type */
unsigned irq;
evtchn_port_t evtchn; /* event channel */
unsigned short cpu; /* cpu bound */
+ unsigned short eoi_cpu; /* EOI must happen on this cpu */
+ unsigned int irq_epoch; /* If eoi_cpu valid: irq_epoch of event */
+ u64 eoi_time; /* Time in jiffies when to EOI. */
union {
unsigned short virq;
@@ -53,6 +58,8 @@ struct irq_info {
#define PIRQ_SHAREABLE (1 << 1)
#define PIRQ_MSI_GROUP (1 << 2)
+struct evtchn_loop_ctrl;
+
struct evtchn_ops {
unsigned (*max_channels)(void);
unsigned (*nr_channels)(void);
@@ -67,14 +74,18 @@ struct evtchn_ops {
void (*mask)(evtchn_port_t port);
void (*unmask)(evtchn_port_t port);
- void (*handle_events)(unsigned cpu);
+ void (*handle_events)(unsigned cpu, struct evtchn_loop_ctrl *ctrl);
void (*resume)(void);
+
+ int (*percpu_init)(unsigned int cpu);
+ int (*percpu_deinit)(unsigned int cpu);
};
extern const struct evtchn_ops *evtchn_ops;
extern int **evtchn_to_irq;
int get_evtchn_to_irq(evtchn_port_t evtchn);
+void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl);
struct irq_info *info_for_irq(unsigned irq);
unsigned cpu_from_irq(unsigned irq);
@@ -132,9 +143,10 @@ static inline void unmask_evtchn(evtchn_port_t port)
return evtchn_ops->unmask(port);
}
-static inline void xen_evtchn_handle_events(unsigned cpu)
+static inline void xen_evtchn_handle_events(unsigned cpu,
+ struct evtchn_loop_ctrl *ctrl)
{
- return evtchn_ops->handle_events(cpu);
+ return evtchn_ops->handle_events(cpu, ctrl);
}
static inline void xen_evtchn_resume(void)