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-rw-r--r--drivers/xen/events/events_2l.c31
-rw-r--r--drivers/xen/events/events_base.c597
-rw-r--r--drivers/xen/events/events_fifo.c107
-rw-r--r--drivers/xen/events/events_internal.h42
-rw-r--r--drivers/xen/evtchn.c7
-rw-r--r--drivers/xen/gntdev.c33
-rw-r--r--drivers/xen/xen-pciback/pci_stub.c14
-rw-r--r--drivers/xen/xen-pciback/pciback.h12
-rw-r--r--drivers/xen/xen-pciback/pciback_ops.c48
-rw-r--r--drivers/xen/xen-pciback/vpci.c14
-rw-r--r--drivers/xen/xen-pciback/xenbus.c26
-rw-r--r--drivers/xen/xen-scsiback.c27
-rw-r--r--drivers/xen/xenbus/xenbus_client.c8
-rw-r--r--drivers/xen/xenbus/xenbus_probe.c1
-rw-r--r--drivers/xen/xenbus/xenbus_probe.h2
-rw-r--r--drivers/xen/xenbus/xenbus_probe_backend.c7
-rw-r--r--drivers/xen/xenbus/xenbus_xs.c38
17 files changed, 789 insertions, 225 deletions
diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c
index 7dd46312c180..ca729f19061d 100644
--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -46,6 +46,11 @@ static unsigned evtchn_2l_max_channels(void)
return EVTCHN_2L_NR_CHANNELS;
}
+static void evtchn_2l_remove(evtchn_port_t evtchn, unsigned int cpu)
+{
+ clear_bit(evtchn, BM(per_cpu(cpu_evtchn_mask, cpu)));
+}
+
static void evtchn_2l_bind_to_cpu(struct irq_info *info, unsigned cpu)
{
clear_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, info->cpu)));
@@ -70,12 +75,6 @@ static bool evtchn_2l_is_pending(unsigned port)
return sync_test_bit(port, BM(&s->evtchn_pending[0]));
}
-static bool evtchn_2l_test_and_set_mask(unsigned port)
-{
- struct shared_info *s = HYPERVISOR_shared_info;
- return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0]));
-}
-
static void evtchn_2l_mask(unsigned port)
{
struct shared_info *s = HYPERVISOR_shared_info;
@@ -90,6 +89,8 @@ static void evtchn_2l_unmask(unsigned 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 {
@@ -158,7 +159,7 @@ 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;
@@ -239,10 +240,7 @@ 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;
@@ -354,18 +352,27 @@ static void evtchn_2l_resume(void)
EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD);
}
+static int evtchn_2l_percpu_deinit(unsigned int cpu)
+{
+ memset(per_cpu(cpu_evtchn_mask, cpu), 0, sizeof(xen_ulong_t) *
+ EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD);
+
+ return 0;
+}
+
static const struct evtchn_ops evtchn_ops_2l = {
.max_channels = evtchn_2l_max_channels,
.nr_channels = evtchn_2l_max_channels,
+ .remove = evtchn_2l_remove,
.bind_to_cpu = evtchn_2l_bind_to_cpu,
.clear_pending = evtchn_2l_clear_pending,
.set_pending = evtchn_2l_set_pending,
.is_pending = evtchn_2l_is_pending,
- .test_and_set_mask = evtchn_2l_test_and_set_mask,
.mask = evtchn_2l_mask,
.unmask = evtchn_2l_unmask,
.handle_events = evtchn_2l_handle_events,
.resume = evtchn_2l_resume,
+ .percpu_deinit = evtchn_2l_percpu_deinit,
};
void __init xen_evtchn_2l_init(void)
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index e4dd991e2888..56bf952de411 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -32,6 +32,10 @@
#include <linux/slab.h>
#include <linux/irqnr.h>
#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/cpu.h>
+#include <linux/atomic.h>
+#include <linux/ktime.h>
#ifdef CONFIG_X86
#include <asm/desc.h>
@@ -62,6 +66,15 @@
#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;
/*
@@ -70,6 +83,25 @@ 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
+ * irq_info->lock
+ */
+
static LIST_HEAD(xen_irq_list_head);
/* IRQ <-> VIRQ mapping. */
@@ -91,18 +123,23 @@ static bool (*pirq_needs_eoi)(unsigned irq);
/* Xen will never allocate port zero for any purpose. */
#define VALID_EVTCHN(chn) ((chn) != 0)
+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)
@@ -139,7 +176,7 @@ static int set_evtchn_to_irq(unsigned evtchn, unsigned irq)
clear_evtchn_to_irq_row(row);
}
- evtchn_to_irq[row][col] = irq;
+ WRITE_ONCE(evtchn_to_irq[row][col], irq);
return 0;
}
@@ -149,13 +186,24 @@ int get_evtchn_to_irq(unsigned 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 */
struct irq_info *info_for_irq(unsigned irq)
{
- return irq_get_chip_data(irq);
+ if (irq < nr_legacy_irqs())
+ return legacy_info_ptrs[irq];
+ else
+ return irq_get_chip_data(irq);
+}
+
+static void set_info_for_irq(unsigned int irq, struct irq_info *info)
+{
+ if (irq < nr_legacy_irqs())
+ legacy_info_ptrs[irq] = info;
+ else
+ irq_set_chip_data(irq, info);
}
/* Constructors for packed IRQ information. */
@@ -173,6 +221,8 @@ 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)
@@ -239,6 +289,7 @@ 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;
}
@@ -247,10 +298,14 @@ static void xen_irq_info_cleanup(struct irq_info *info)
*/
unsigned int evtchn_from_irq(unsigned irq)
{
- if (unlikely(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 irq_from_evtchn(unsigned int evtchn)
@@ -315,6 +370,34 @@ unsigned int cpu_from_evtchn(unsigned int 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)
{
@@ -369,9 +452,157 @@ 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;
+ do_unmask(info, EVT_MASK_REASON_EOI_PENDING);
+}
+
+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));
@@ -384,8 +615,9 @@ static void xen_irq_init(unsigned irq)
info->type = IRQT_UNBOUND;
info->refcnt = -1;
- irq_set_chip_data(irq, info);
+ set_info_for_irq(irq, info);
+ INIT_LIST_HEAD(&info->eoi_list);
list_add_tail(&info->list, &xen_irq_list_head);
}
@@ -433,17 +665,25 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi)
static void xen_free_irq(unsigned irq)
{
- struct irq_info *info = irq_get_chip_data(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);
- irq_set_chip_data(irq, NULL);
+ 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. */
@@ -462,6 +702,12 @@ static void xen_evtchn_close(unsigned int 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;
@@ -480,7 +726,8 @@ static void pirq_query_unmask(int irq)
static void eoi_pirq(struct irq_data *data)
{
- int evtchn = evtchn_from_irq(data->irq);
+ struct irq_info *info = info_for_irq(data->irq);
+ int evtchn = info ? info->evtchn : 0;
struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
int rc = 0;
@@ -489,16 +736,15 @@ static void eoi_pirq(struct irq_data *data)
if (unlikely(irqd_is_setaffinity_pending(data)) &&
likely(!irqd_irq_disabled(data))) {
- int masked = test_and_set_mask(evtchn);
+ do_mask(info, EVT_MASK_REASON_TEMPORARY);
- clear_evtchn(evtchn);
+ event_handler_exit(info);
irq_move_masked_irq(data);
- if (!masked)
- unmask_evtchn(evtchn);
+ do_unmask(info, EVT_MASK_REASON_TEMPORARY);
} else
- clear_evtchn(evtchn);
+ event_handler_exit(info);
if (pirq_needs_eoi(data->irq)) {
rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
@@ -549,7 +795,8 @@ 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;
@@ -576,7 +823,7 @@ 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);
}
@@ -610,7 +857,7 @@ EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
static void __unbind_from_irq(unsigned int irq)
{
int evtchn = evtchn_from_irq(irq);
- struct irq_info *info = irq_get_chip_data(irq);
+ struct irq_info *info = info_for_irq(irq);
if (info->refcnt > 0) {
info->refcnt--;
@@ -835,7 +1082,7 @@ int xen_pirq_from_irq(unsigned irq)
}
EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
-int bind_evtchn_to_irq(unsigned int evtchn)
+static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip)
{
int irq;
int ret;
@@ -852,7 +1099,7 @@ int bind_evtchn_to_irq(unsigned int 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);
@@ -873,8 +1120,19 @@ 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;
@@ -916,8 +1174,9 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
return irq;
}
-int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
- unsigned int 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;
@@ -928,10 +1187,26 @@ 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)
{
struct evtchn_status status;
@@ -1027,14 +1302,15 @@ static void unbind_from_irq(unsigned int irq)
mutex_unlock(&irq_mapping_update_lock);
}
-int bind_evtchn_to_irqhandler(unsigned int 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);
@@ -1045,18 +1321,38 @@ int bind_evtchn_to_irqhandler(unsigned int 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,
- unsigned int 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;
@@ -1068,8 +1364,33 @@ 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)
@@ -1114,7 +1435,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi,
void unbind_from_irqhandler(unsigned int irq, void *dev_id)
{
- struct irq_info *info = irq_get_chip_data(irq);
+ struct irq_info *info = info_for_irq(irq);
if (WARN_ON(!info))
return;
@@ -1148,7 +1469,7 @@ int evtchn_make_refcounted(unsigned int evtchn)
if (irq == -1)
return -ENOENT;
- info = irq_get_chip_data(irq);
+ info = info_for_irq(irq);
if (!info)
return -ENOENT;
@@ -1176,13 +1497,13 @@ int evtchn_get(unsigned int evtchn)
if (irq == -1)
goto done;
- info = irq_get_chip_data(irq);
+ info = info_for_irq(irq);
if (!info)
goto done;
err = -EINVAL;
- if (info->refcnt <= 0)
+ if (info->refcnt <= 0 || info->refcnt == SHRT_MAX)
goto done;
info->refcnt++;
@@ -1220,6 +1541,56 @@ 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.tv64) {
+ kt = ktime_add_ms(kt,
+ jiffies_to_msecs(event_loop_timeout));
+ ctrl->timeout = kt;
+ } else if (kt.tv64 > ctrl->timeout.tv64) {
+ ctrl->defer_eoi = true;
+ }
+ }
+
+ info = info_for_irq(irq);
+ if (xchg_acquire(&info->is_active, 1))
+ return;
+
+ 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 DEFINE_PER_CPU(unsigned, xed_nesting_count);
static void __xen_evtchn_do_upcall(void)
@@ -1227,6 +1598,9 @@ static void __xen_evtchn_do_upcall(void)
struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
int cpu = get_cpu();
unsigned count;
+ struct evtchn_loop_ctrl ctrl = { 0 };
+
+ read_lock(&evtchn_rwlock);
do {
vcpu_info->evtchn_upcall_pending = 0;
@@ -1234,7 +1608,7 @@ static void __xen_evtchn_do_upcall(void)
if (__this_cpu_inc_return(xed_nesting_count) - 1)
goto out;
- xen_evtchn_handle_events(cpu);
+ xen_evtchn_handle_events(cpu, &ctrl);
BUG_ON(!irqs_disabled());
@@ -1243,6 +1617,14 @@ static void __xen_evtchn_do_upcall(void)
} while (count != 1 || vcpu_info->evtchn_upcall_pending);
out:
+ 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);
put_cpu();
}
@@ -1305,8 +1687,8 @@ void rebind_evtchn_irq(int evtchn, int irq)
static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
{
struct evtchn_bind_vcpu bind_vcpu;
- int evtchn = evtchn_from_irq(irq);
- int masked;
+ struct irq_info *info = info_for_irq(irq);
+ int evtchn = info ? info->evtchn : 0;
if (!VALID_EVTCHN(evtchn))
return -1;
@@ -1322,7 +1704,7 @@ static int rebind_irq_to_cpu(unsigned irq, unsigned 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
@@ -1332,8 +1714,7 @@ static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
bind_evtchn_to_cpu(evtchn, tcpu);
- if (!masked)
- unmask_evtchn(evtchn);
+ do_unmask(info, EVT_MASK_REASON_TEMPORARY);
return 0;
}
@@ -1348,39 +1729,41 @@ static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
static void enable_dynirq(struct irq_data *data)
{
- int 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)
{
- int 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)
{
- int 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;
if (unlikely(irqd_is_setaffinity_pending(data)) &&
likely(!irqd_irq_disabled(data))) {
- int masked = test_and_set_mask(evtchn);
+ do_mask(info, EVT_MASK_REASON_TEMPORARY);
- clear_evtchn(evtchn);
+ event_handler_exit(info);
irq_move_masked_irq(data);
- if (!masked)
- unmask_evtchn(evtchn);
+ do_unmask(info, EVT_MASK_REASON_TEMPORARY);
} else
- clear_evtchn(evtchn);
+ event_handler_exit(info);
}
static void mask_ack_dynirq(struct irq_data *data)
@@ -1389,18 +1772,39 @@ 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);
+ ack_dynirq(data);
+ }
+}
+
+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);
+ ack_dynirq(data);
+ }
+}
+
static int retrigger_dynirq(struct irq_data *data)
{
- unsigned int 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;
}
@@ -1495,10 +1899,11 @@ 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)
{
- int 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)
@@ -1599,6 +2004,21 @@ 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 = lateeoi_ack_dynirq,
+ .irq_mask_ack = lateeoi_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",
@@ -1666,12 +2086,55 @@ void xen_callback_vector(void)
void xen_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;
+}
+
+static int evtchn_cpu_notification(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ int cpu = (long)hcpu;
+ int ret = 0;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ ret = xen_evtchn_cpu_prepare(cpu);
+ break;
+ case CPU_DEAD:
+ ret = xen_evtchn_cpu_dead(cpu);
+ break;
+ default:
+ break;
+ }
+
+ return ret < 0 ? NOTIFY_BAD : NOTIFY_OK;
+}
+
+static struct notifier_block evtchn_cpu_notifier = {
+ .notifier_call = evtchn_cpu_notification,
+};
+
void __init xen_init_IRQ(void)
{
int ret = -EINVAL;
@@ -1681,6 +2144,10 @@ void __init xen_init_IRQ(void)
if (ret < 0)
xen_evtchn_2l_init();
+ xen_cpu_init_eoi(smp_processor_id());
+
+ register_cpu_notifier(&evtchn_cpu_notifier);
+
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 96a1b8da5371..5e6ff2120132 100644
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -209,12 +209,6 @@ static bool evtchn_fifo_is_pending(unsigned port)
return sync_test_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
}
-static bool evtchn_fifo_test_and_set_mask(unsigned port)
-{
- event_word_t *word = event_word_from_port(port);
- return sync_test_and_set_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
-}
-
static void evtchn_fifo_mask(unsigned port)
{
event_word_t *word = event_word_from_port(port);
@@ -227,19 +221,25 @@ static bool evtchn_fifo_is_masked(unsigned 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(unsigned port)
@@ -248,8 +248,7 @@ static void evtchn_fifo_unmask(unsigned 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 +269,9 @@ static uint32_t clear_linked(volatile event_word_t *word)
return w & EVTCHN_FIFO_LINK_MASK;
}
-static void handle_irq_for_port(unsigned 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 +304,17 @@ 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 +326,15 @@ 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)
@@ -381,21 +372,6 @@ 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;
@@ -418,29 +394,33 @@ static int evtchn_fifo_alloc_control_block(unsigned cpu)
return ret;
}
-static int evtchn_fifo_cpu_notification(struct notifier_block *self,
- unsigned long action,
- void *hcpu)
+static int evtchn_fifo_percpu_init(unsigned int cpu)
{
- int cpu = (long)hcpu;
- int ret = 0;
-
- switch (action) {
- case CPU_UP_PREPARE:
- if (!per_cpu(cpu_control_block, cpu))
- ret = evtchn_fifo_alloc_control_block(cpu);
- break;
- case CPU_DEAD:
- __evtchn_fifo_handle_events(cpu, true);
- break;
- default:
- break;
- }
- return ret < 0 ? NOTIFY_BAD : NOTIFY_OK;
+ if (!per_cpu(cpu_control_block, cpu))
+ return evtchn_fifo_alloc_control_block(cpu);
+ return 0;
}
-static struct notifier_block evtchn_fifo_cpu_notifier = {
- .notifier_call = evtchn_fifo_cpu_notification,
+static int evtchn_fifo_percpu_deinit(unsigned int cpu)
+{
+ __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,
+ .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)
@@ -456,7 +436,6 @@ int __init xen_evtchn_fifo_init(void)
evtchn_ops = &evtchn_ops_fifo;
- register_cpu_notifier(&evtchn_fifo_cpu_notifier);
out:
put_cpu();
return ret;
diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h
index 50c2050a1e32..cc37b711491c 100644
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -32,11 +32,22 @@ enum xen_irq_type {
*/
struct irq_info {
struct list_head list;
- int refcnt;
- enum xen_irq_type type; /* type */
+ struct list_head eoi_list;
+ short refcnt;
+ short spurious_cnt;
+ short type; /* type */
+ 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;
unsigned int 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. */
+ raw_spinlock_t lock;
union {
unsigned short virq;
@@ -55,28 +66,34 @@ 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);
int (*setup)(struct irq_info *info);
+ void (*remove)(evtchn_port_t port, unsigned int cpu);
void (*bind_to_cpu)(struct irq_info *info, unsigned cpu);
void (*clear_pending)(unsigned port);
void (*set_pending)(unsigned port);
bool (*is_pending)(unsigned port);
- bool (*test_and_set_mask)(unsigned port);
void (*mask)(unsigned port);
void (*unmask)(unsigned 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(unsigned int 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);
@@ -98,6 +115,13 @@ static inline int xen_evtchn_port_setup(struct irq_info *info)
return 0;
}
+static inline void xen_evtchn_port_remove(evtchn_port_t evtchn,
+ unsigned int cpu)
+{
+ if (evtchn_ops->remove)
+ evtchn_ops->remove(evtchn, cpu);
+}
+
static inline void xen_evtchn_port_bind_to_cpu(struct irq_info *info,
unsigned cpu)
{
@@ -119,11 +143,6 @@ static inline bool test_evtchn(unsigned port)
return evtchn_ops->is_pending(port);
}
-static inline bool test_and_set_mask(unsigned port)
-{
- return evtchn_ops->test_and_set_mask(port);
-}
-
static inline void mask_evtchn(unsigned port)
{
return evtchn_ops->mask(port);
@@ -134,9 +153,10 @@ static inline void unmask_evtchn(unsigned 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)
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index f4edd6df3df2..96c3007576b6 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -173,7 +173,6 @@ static irqreturn_t evtchn_interrupt(int irq, void *data)
"Interrupt for port %d, but apparently not enabled; per-user %p\n",
evtchn->port, u);
- disable_irq_nosync(irq);
evtchn->enabled = false;
spin_lock(&u->ring_prod_lock);
@@ -299,7 +298,7 @@ static ssize_t evtchn_write(struct file *file, const char __user *buf,
evtchn = find_evtchn(u, port);
if (evtchn && !evtchn->enabled) {
evtchn->enabled = true;
- enable_irq(irq_from_evtchn(port));
+ xen_irq_lateeoi(irq_from_evtchn(port), 0);
}
}
@@ -399,8 +398,8 @@ static int evtchn_bind_to_user(struct per_user_data *u, int port)
if (rc < 0)
goto err;
- rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0,
- u->name, evtchn);
+ rc = bind_evtchn_to_irqhandler_lateeoi(port, evtchn_interrupt, 0,
+ u->name, evtchn);
if (rc < 0)
goto err;
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 1865bcfa869b..6f077ae0cf31 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -293,36 +293,47 @@ static int map_grant_pages(struct grant_map *map)
* to the kernel linear addresses of the struct pages.
* These ptes are completely different from the user ptes dealt
* with find_grant_ptes.
+ * Note that GNTMAP_device_map isn't needed here: The
+ * dev_bus_addr output field gets consumed only from ->map_ops,
+ * and by not requesting it when mapping we also avoid needing
+ * to mirror dev_bus_addr into ->unmap_ops (and holding an extra
+ * reference to the page in the hypervisor).
*/
+ unsigned int flags = (map->flags & ~GNTMAP_device_map) |
+ GNTMAP_host_map;
+
for (i = 0; i < map->count; i++) {
unsigned long address = (unsigned long)
pfn_to_kaddr(page_to_pfn(map->pages[i]));
BUG_ON(PageHighMem(map->pages[i]));
- gnttab_set_map_op(&map->kmap_ops[i], address,
- map->flags | GNTMAP_host_map,
+ gnttab_set_map_op(&map->kmap_ops[i], address, flags,
map->grants[i].ref,
map->grants[i].domid);
gnttab_set_unmap_op(&map->kunmap_ops[i], address,
- map->flags | GNTMAP_host_map, -1);
+ flags, -1);
}
}
pr_debug("map %d+%d\n", map->index, map->count);
err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
map->pages, map->count);
- if (err)
- return err;
for (i = 0; i < map->count; i++) {
- if (map->map_ops[i].status) {
+ if (map->map_ops[i].status == GNTST_okay)
+ map->unmap_ops[i].handle = map->map_ops[i].handle;
+ else if (!err)
err = -EINVAL;
- continue;
- }
- map->unmap_ops[i].handle = map->map_ops[i].handle;
- if (use_ptemod)
- map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
+ if (map->flags & GNTMAP_device_map)
+ map->unmap_ops[i].dev_bus_addr = map->map_ops[i].dev_bus_addr;
+
+ if (use_ptemod) {
+ if (map->kmap_ops[i].status == GNTST_okay)
+ map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
+ else if (!err)
+ err = -EINVAL;
+ }
}
return err;
}
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 47c6df53cabf..e21b82921c33 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -681,10 +681,17 @@ static pci_ers_result_t common_process(struct pcistub_device *psdev,
wmb();
notify_remote_via_irq(pdev->evtchn_irq);
+ /* Enable IRQ to signal "request done". */
+ xen_pcibk_lateeoi(pdev, 0);
+
ret = wait_event_timeout(xen_pcibk_aer_wait_queue,
!(test_bit(_XEN_PCIB_active, (unsigned long *)
&sh_info->flags)), 300*HZ);
+ /* Enable IRQ for pcifront request if not already active. */
+ if (!test_bit(_PDEVF_op_active, &pdev->flags))
+ xen_pcibk_lateeoi(pdev, 0);
+
if (!ret) {
if (test_bit(_XEN_PCIB_active,
(unsigned long *)&sh_info->flags)) {
@@ -698,13 +705,6 @@ static pci_ers_result_t common_process(struct pcistub_device *psdev,
}
clear_bit(_PCIB_op_pending, (unsigned long *)&pdev->flags);
- if (test_bit(_XEN_PCIF_active,
- (unsigned long *)&sh_info->flags)) {
- dev_dbg(&psdev->dev->dev,
- "schedule pci_conf service in " DRV_NAME "\n");
- xen_pcibk_test_and_schedule_op(psdev->pdev);
- }
-
res = (pci_ers_result_t)aer_op->err;
return res;
}
diff --git a/drivers/xen/xen-pciback/pciback.h b/drivers/xen/xen-pciback/pciback.h
index 4d529f3e40df..f44a425d1a5a 100644
--- a/drivers/xen/xen-pciback/pciback.h
+++ b/drivers/xen/xen-pciback/pciback.h
@@ -13,6 +13,7 @@
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/atomic.h>
+#include <xen/events.h>
#include <xen/interface/io/pciif.h>
#define DRV_NAME "xen-pciback"
@@ -26,6 +27,8 @@ struct pci_dev_entry {
#define PDEVF_op_active (1<<(_PDEVF_op_active))
#define _PCIB_op_pending (1)
#define PCIB_op_pending (1<<(_PCIB_op_pending))
+#define _EOI_pending (2)
+#define EOI_pending (1<<(_EOI_pending))
struct xen_pcibk_device {
void *pci_dev_data;
@@ -182,12 +185,17 @@ static inline void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id);
void xen_pcibk_do_op(struct work_struct *data);
+static inline void xen_pcibk_lateeoi(struct xen_pcibk_device *pdev,
+ unsigned int eoi_flag)
+{
+ if (test_and_clear_bit(_EOI_pending, &pdev->flags))
+ xen_irq_lateeoi(pdev->evtchn_irq, eoi_flag);
+}
+
int xen_pcibk_xenbus_register(void);
void xen_pcibk_xenbus_unregister(void);
extern int verbose_request;
-
-void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev);
#endif
/* Handles shared IRQs that can to device domain and control domain. */
diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
index 49c5f0e9600a..232db7fcc523 100644
--- a/drivers/xen/xen-pciback/pciback_ops.c
+++ b/drivers/xen/xen-pciback/pciback_ops.c
@@ -296,26 +296,41 @@ int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
return 0;
}
#endif
+
+static inline bool xen_pcibk_test_op_pending(struct xen_pcibk_device *pdev)
+{
+ return test_bit(_XEN_PCIF_active,
+ (unsigned long *)&pdev->sh_info->flags) &&
+ !test_and_set_bit(_PDEVF_op_active, &pdev->flags);
+}
+
/*
* Now the same evtchn is used for both pcifront conf_read_write request
* as well as pcie aer front end ack. We use a new work_queue to schedule
* xen_pcibk conf_read_write service for avoiding confict with aer_core
* do_recovery job which also use the system default work_queue
*/
-void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
+static void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
{
+ bool eoi = true;
+
/* Check that frontend is requesting an operation and that we are not
* already processing a request */
- if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
- && !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
+ if (xen_pcibk_test_op_pending(pdev)) {
queue_work(xen_pcibk_wq, &pdev->op_work);
+ eoi = false;
}
/*_XEN_PCIB_active should have been cleared by pcifront. And also make
sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
&& test_bit(_PCIB_op_pending, &pdev->flags)) {
wake_up(&xen_pcibk_aer_wait_queue);
+ eoi = false;
}
+
+ /* EOI if there was nothing to do. */
+ if (eoi)
+ xen_pcibk_lateeoi(pdev, XEN_EOI_FLAG_SPURIOUS);
}
/* Performing the configuration space reads/writes must not be done in atomic
@@ -323,10 +338,8 @@ void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
* use of semaphores). This function is intended to be called from a work
* queue in process context taking a struct xen_pcibk_device as a parameter */
-void xen_pcibk_do_op(struct work_struct *data)
+static void xen_pcibk_do_one_op(struct xen_pcibk_device *pdev)
{
- struct xen_pcibk_device *pdev =
- container_of(data, struct xen_pcibk_device, op_work);
struct pci_dev *dev;
struct xen_pcibk_dev_data *dev_data = NULL;
struct xen_pci_op *op = &pdev->op;
@@ -399,16 +412,31 @@ void xen_pcibk_do_op(struct work_struct *data)
smp_mb__before_atomic(); /* /after/ clearing PCIF_active */
clear_bit(_PDEVF_op_active, &pdev->flags);
smp_mb__after_atomic(); /* /before/ final check for work */
+}
- /* Check to see if the driver domain tried to start another request in
- * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
- */
- xen_pcibk_test_and_schedule_op(pdev);
+void xen_pcibk_do_op(struct work_struct *data)
+{
+ struct xen_pcibk_device *pdev =
+ container_of(data, struct xen_pcibk_device, op_work);
+
+ do {
+ xen_pcibk_do_one_op(pdev);
+ } while (xen_pcibk_test_op_pending(pdev));
+
+ xen_pcibk_lateeoi(pdev, 0);
}
irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
{
struct xen_pcibk_device *pdev = dev_id;
+ bool eoi;
+
+ /* IRQs might come in before pdev->evtchn_irq is written. */
+ if (unlikely(pdev->evtchn_irq != irq))
+ pdev->evtchn_irq = irq;
+
+ eoi = test_and_set_bit(_EOI_pending, &pdev->flags);
+ WARN(eoi, "IRQ while EOI pending\n");
xen_pcibk_test_and_schedule_op(pdev);
diff --git a/drivers/xen/xen-pciback/vpci.c b/drivers/xen/xen-pciback/vpci.c
index c99f8bb1c56c..e6c7509a3d87 100644
--- a/drivers/xen/xen-pciback/vpci.c
+++ b/drivers/xen/xen-pciback/vpci.c
@@ -68,7 +68,7 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
struct pci_dev *dev, int devid,
publish_pci_dev_cb publish_cb)
{
- int err = 0, slot, func = -1;
+ int err = 0, slot, func = PCI_FUNC(dev->devfn);
struct pci_dev_entry *t, *dev_entry;
struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
@@ -93,23 +93,26 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
/*
* Keep multi-function devices together on the virtual PCI bus, except
- * virtual functions.
+ * that we want to keep virtual functions at func 0 on their own. They
+ * aren't multi-function devices and hence their presence at func 0
+ * may cause guests to not scan the other functions.
*/
- if (!dev->is_virtfn) {
+ if (!dev->is_virtfn || func) {
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
if (list_empty(&vpci_dev->dev_list[slot]))
continue;
t = list_entry(list_first(&vpci_dev->dev_list[slot]),
struct pci_dev_entry, list);
+ if (t->dev->is_virtfn && !PCI_FUNC(t->dev->devfn))
+ continue;
if (match_slot(dev, t->dev)) {
pr_info("vpci: %s: assign to virtual slot %d func %d\n",
pci_name(dev), slot,
- PCI_FUNC(dev->devfn));
+ func);
list_add_tail(&dev_entry->list,
&vpci_dev->dev_list[slot]);
- func = PCI_FUNC(dev->devfn);
goto unlock;
}
}
@@ -122,7 +125,6 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
pci_name(dev), slot);
list_add_tail(&dev_entry->list,
&vpci_dev->dev_list[slot]);
- func = dev->is_virtfn ? 0 : PCI_FUNC(dev->devfn);
goto unlock;
}
}
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index 4843741e703a..c784a01aa8cb 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -124,7 +124,7 @@ static int xen_pcibk_do_attach(struct xen_pcibk_device *pdev, int gnt_ref,
pdev->sh_info = vaddr;
- err = bind_interdomain_evtchn_to_irqhandler(
+ err = bind_interdomain_evtchn_to_irqhandler_lateeoi(
pdev->xdev->otherend_id, remote_evtchn, xen_pcibk_handle_event,
0, DRV_NAME, pdev);
if (err < 0) {
@@ -359,7 +359,8 @@ out:
return err;
}
-static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev)
+static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev,
+ enum xenbus_state state)
{
int err = 0;
int num_devs;
@@ -373,9 +374,7 @@ static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev)
dev_dbg(&pdev->xdev->dev, "Reconfiguring device ...\n");
mutex_lock(&pdev->dev_lock);
- /* Make sure we only reconfigure once */
- if (xenbus_read_driver_state(pdev->xdev->nodename) !=
- XenbusStateReconfiguring)
+ if (xenbus_read_driver_state(pdev->xdev->nodename) != state)
goto out;
err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, "num_devs", "%d",
@@ -502,6 +501,10 @@ static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev)
}
}
+ if (state != XenbusStateReconfiguring)
+ /* Make sure we only reconfigure once. */
+ goto out;
+
err = xenbus_switch_state(pdev->xdev, XenbusStateReconfigured);
if (err) {
xenbus_dev_fatal(pdev->xdev, err,
@@ -527,7 +530,7 @@ static void xen_pcibk_frontend_changed(struct xenbus_device *xdev,
break;
case XenbusStateReconfiguring:
- xen_pcibk_reconfigure(pdev);
+ xen_pcibk_reconfigure(pdev, XenbusStateReconfiguring);
break;
case XenbusStateConnected:
@@ -666,6 +669,15 @@ static void xen_pcibk_be_watch(struct xenbus_watch *watch,
xen_pcibk_setup_backend(pdev);
break;
+ case XenbusStateInitialised:
+ /*
+ * We typically move to Initialised when the first device was
+ * added. Hence subsequent devices getting added may need
+ * reconfiguring.
+ */
+ xen_pcibk_reconfigure(pdev, XenbusStateInitialised);
+ break;
+
default:
break;
}
@@ -691,7 +703,7 @@ static int xen_pcibk_xenbus_probe(struct xenbus_device *dev,
/* watch the backend node for backend configuration information */
err = xenbus_watch_path(dev, dev->nodename, &pdev->be_watch,
- xen_pcibk_be_watch);
+ NULL, xen_pcibk_be_watch);
if (err)
goto out;
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 51387d75c7bf..7fb5a2e7fa81 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -91,7 +91,6 @@ struct vscsibk_info {
unsigned int irq;
struct vscsiif_back_ring ring;
- int ring_error;
spinlock_t ring_lock;
atomic_t nr_unreplied_reqs;
@@ -416,12 +415,12 @@ static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
return 0;
err = gnttab_map_refs(map, NULL, pg, cnt);
- BUG_ON(err);
for (i = 0; i < cnt; i++) {
if (unlikely(map[i].status != GNTST_okay)) {
pr_err("invalid buffer -- could not remap it\n");
map[i].handle = SCSIBACK_INVALID_HANDLE;
- err = -ENOMEM;
+ if (!err)
+ err = -ENOMEM;
} else {
get_page(pg[i]);
}
@@ -698,7 +697,8 @@ static int prepare_pending_reqs(struct vscsibk_info *info,
return 0;
}
-static int scsiback_do_cmd_fn(struct vscsibk_info *info)
+static int scsiback_do_cmd_fn(struct vscsibk_info *info,
+ unsigned int *eoi_flags)
{
struct vscsiif_back_ring *ring = &info->ring;
struct vscsiif_request ring_req;
@@ -715,11 +715,12 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
rc = ring->rsp_prod_pvt;
pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
info->domid, rp, rc, rp - rc);
- info->ring_error = 1;
- return 0;
+ return -EINVAL;
}
while ((rc != rp)) {
+ *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
+
if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
break;
pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
@@ -782,13 +783,16 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
{
struct vscsibk_info *info = dev_id;
+ int rc;
+ unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
- if (info->ring_error)
- return IRQ_HANDLED;
-
- while (scsiback_do_cmd_fn(info))
+ while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
cond_resched();
+ /* In case of a ring error we keep the event channel masked. */
+ if (!rc)
+ xen_irq_lateeoi(irq, eoi_flags);
+
return IRQ_HANDLED;
}
@@ -809,7 +813,7 @@ static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
sring = (struct vscsiif_sring *)area;
BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
- err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
+ err = bind_interdomain_evtchn_to_irq_lateeoi(info->domid, evtchn);
if (err < 0)
goto unmap_page;
@@ -1210,7 +1214,6 @@ static int scsiback_probe(struct xenbus_device *dev,
info->domid = dev->otherend_id;
spin_lock_init(&info->ring_lock);
- info->ring_error = 0;
atomic_set(&info->nr_unreplied_reqs, 0);
init_waitqueue_head(&info->waiting_to_free);
info->dev = dev;
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index 266f446ba331..8bbd887ca422 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -114,18 +114,22 @@ EXPORT_SYMBOL_GPL(xenbus_strstate);
*/
int xenbus_watch_path(struct xenbus_device *dev, const char *path,
struct xenbus_watch *watch,
+ bool (*will_handle)(struct xenbus_watch *,
+ const char **, unsigned int),
void (*callback)(struct xenbus_watch *,
const char **, unsigned int))
{
int err;
watch->node = path;
+ watch->will_handle = will_handle;
watch->callback = callback;
err = register_xenbus_watch(watch);
if (err) {
watch->node = NULL;
+ watch->will_handle = NULL;
watch->callback = NULL;
xenbus_dev_fatal(dev, err, "adding watch on %s", path);
}
@@ -152,6 +156,8 @@ EXPORT_SYMBOL_GPL(xenbus_watch_path);
*/
int xenbus_watch_pathfmt(struct xenbus_device *dev,
struct xenbus_watch *watch,
+ bool (*will_handle)(struct xenbus_watch *,
+ const char **, unsigned int),
void (*callback)(struct xenbus_watch *,
const char **, unsigned int),
const char *pathfmt, ...)
@@ -168,7 +174,7 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev,
xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch");
return -ENOMEM;
}
- err = xenbus_watch_path(dev, path, watch, callback);
+ err = xenbus_watch_path(dev, path, watch, will_handle, callback);
if (err)
kfree(path);
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index c2d447687e33..ba7590d75985 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -137,6 +137,7 @@ static int watch_otherend(struct xenbus_device *dev)
container_of(dev->dev.bus, struct xen_bus_type, bus);
return xenbus_watch_pathfmt(dev, &dev->otherend_watch,
+ bus->otherend_will_handle,
bus->otherend_changed,
"%s/%s", dev->otherend, "state");
}
diff --git a/drivers/xen/xenbus/xenbus_probe.h b/drivers/xen/xenbus/xenbus_probe.h
index c9ec7ca1f7ab..2c394c6ba605 100644
--- a/drivers/xen/xenbus/xenbus_probe.h
+++ b/drivers/xen/xenbus/xenbus_probe.h
@@ -42,6 +42,8 @@ struct xen_bus_type {
int (*get_bus_id)(char bus_id[XEN_BUS_ID_SIZE], const char *nodename);
int (*probe)(struct xen_bus_type *bus, const char *type,
const char *dir);
+ bool (*otherend_will_handle)(struct xenbus_watch *watch,
+ const char **vec, unsigned int len);
void (*otherend_changed)(struct xenbus_watch *watch, const char **vec,
unsigned int len);
struct bus_type bus;
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index 04f7f85a5edf..597c0b038454 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -181,6 +181,12 @@ static int xenbus_probe_backend(struct xen_bus_type *bus, const char *type,
return err;
}
+static bool frontend_will_handle(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ return watch->nr_pending == 0;
+}
+
static void frontend_changed(struct xenbus_watch *watch,
const char **vec, unsigned int len)
{
@@ -192,6 +198,7 @@ static struct xen_bus_type xenbus_backend = {
.levels = 3, /* backend/type/<frontend>/<id> */
.get_bus_id = backend_bus_id,
.probe = xenbus_probe_backend,
+ .otherend_will_handle = frontend_will_handle,
.otherend_changed = frontend_changed,
.bus = {
.name = "xen-backend",
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index ce65591b4168..d98d88fae58a 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -701,6 +701,8 @@ int register_xenbus_watch(struct xenbus_watch *watch)
sprintf(token, "%lX", (long)watch);
+ watch->nr_pending = 0;
+
down_read(&xs_state.watch_mutex);
spin_lock(&watches_lock);
@@ -750,12 +752,15 @@ void unregister_xenbus_watch(struct xenbus_watch *watch)
/* Cancel pending watch events. */
spin_lock(&watch_events_lock);
- list_for_each_entry_safe(msg, tmp, &watch_events, list) {
- if (msg->u.watch.handle != watch)
- continue;
- list_del(&msg->list);
- kfree(msg->u.watch.vec);
- kfree(msg);
+ if (watch->nr_pending) {
+ list_for_each_entry_safe(msg, tmp, &watch_events, list) {
+ if (msg->u.watch.handle != watch)
+ continue;
+ list_del(&msg->list);
+ kfree(msg->u.watch.vec);
+ kfree(msg);
+ }
+ watch->nr_pending = 0;
}
spin_unlock(&watch_events_lock);
@@ -802,7 +807,6 @@ void xs_suspend_cancel(void)
static int xenwatch_thread(void *unused)
{
- struct list_head *ent;
struct xs_stored_msg *msg;
for (;;) {
@@ -815,13 +819,15 @@ static int xenwatch_thread(void *unused)
mutex_lock(&xenwatch_mutex);
spin_lock(&watch_events_lock);
- ent = watch_events.next;
- if (ent != &watch_events)
- list_del(ent);
+ msg = list_first_entry_or_null(&watch_events,
+ struct xs_stored_msg, list);
+ if (msg) {
+ list_del(&msg->list);
+ msg->u.watch.handle->nr_pending--;
+ }
spin_unlock(&watch_events_lock);
- if (ent != &watch_events) {
- msg = list_entry(ent, struct xs_stored_msg, list);
+ if (msg) {
msg->u.watch.handle->callback(
msg->u.watch.handle,
(const char **)msg->u.watch.vec,
@@ -903,9 +909,15 @@ static int process_msg(void)
spin_lock(&watches_lock);
msg->u.watch.handle = find_watch(
msg->u.watch.vec[XS_WATCH_TOKEN]);
- if (msg->u.watch.handle != NULL) {
+ if (msg->u.watch.handle != NULL &&
+ (!msg->u.watch.handle->will_handle ||
+ msg->u.watch.handle->will_handle(
+ msg->u.watch.handle,
+ (const char **)msg->u.watch.vec,
+ msg->u.watch.vec_size))) {
spin_lock(&watch_events_lock);
list_add_tail(&msg->list, &watch_events);
+ msg->u.watch.handle->nr_pending++;
wake_up(&watch_events_waitq);
spin_unlock(&watch_events_lock);
} else {
generated by cgit v1.2.3 (git 2.0.4) at 2024-06-03 15:55:38 +0000