[RFC PATCH V4 06/18] Add evtchn_is_{pending, masked} and evtchn_clear_pending

[Wei Liu <wei.liu2@citrix.com>]

Some code paths access the arrays in shared info directly. This only
works with 2-level event channel.

Add functions to abstract away implementation details.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 xen/arch/x86/irq.c         |    7 +++----
 xen/common/event_channel.c |   22 +++++++++++++++++++---
 xen/common/keyhandler.c    |    6 ++----
 xen/common/schedule.c      |    2 +-
 xen/include/xen/event.h    |    6 ++++++
 5 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index ca829bb..4033328 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -1452,7 +1452,7 @@ int pirq_guest_unmask(struct domain *d)
         {
             pirq = pirqs[i]->pirq;
             if ( pirqs[i]->masked &&
-                 !test_bit(pirqs[i]->evtchn, &shared_info(d, evtchn_mask)) )
+                 !evtchn_is_masked(d, pirqs[i]->evtchn) )
                 pirq_guest_eoi(pirqs[i]);
         }
     } while ( ++pirq < d->nr_pirqs && n == ARRAY_SIZE(pirqs) );
@@ -2090,13 +2090,12 @@ static void dump_irqs(unsigned char key)
                 info = pirq_info(d, pirq);
                 printk("%u:%3d(%c%c%c%c)",
                        d->domain_id, pirq,
-                       (test_bit(info->evtchn,
-                                 &shared_info(d, evtchn_pending)) ?
+                       (evtchn_is_pending(d, info->evtchn) ?
                         'P' : '-'),
                        (test_bit(info->evtchn / BITS_PER_EVTCHN_WORD(d),
                                  &vcpu_info(d->vcpu[0], evtchn_pending_sel)) ?
                         'S' : '-'),
-                       (test_bit(info->evtchn, &shared_info(d, evtchn_mask)) ?
+                       (evtchn_is_masked(d, info->evtchn) ?
                         'M' : '-'),
                        (info->masked ? 'M' : '-'));
                 if ( i != action->nr_guests )
diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 0205c73..667fd89 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -95,6 +95,7 @@ static uint8_t get_xen_consumer(xen_event_channel_notification_t fn)
 #define xen_notification_fn(e) (xen_consumers[(e)->xen_consumer-1])
 
 static void evtchn_set_pending(struct vcpu *v, int port);
+static void evtchn_clear_pending(struct domain *d, int port);
 
 static int virq_is_global(uint32_t virq)
 {
@@ -156,6 +157,16 @@ static int get_free_port(struct domain *d)
     return port;
 }
 
+int evtchn_is_pending(struct domain *d, int port)
+{
+    return test_bit(port, &shared_info(d, evtchn_pending));
+}
+
+int evtchn_is_masked(struct domain *d, int port)
+{
+    return test_bit(port, &shared_info(d, evtchn_mask));
+}
+
 
 static long evtchn_alloc_unbound(evtchn_alloc_unbound_t *alloc)
 {
@@ -529,7 +540,7 @@ static long __evtchn_close(struct domain *d1, int port1)
     }
 
     /* Clear pending event to avoid unexpected behavior on re-bind. */
-    clear_bit(port1, &shared_info(d1, evtchn_pending));
+    evtchn_clear_pending(d1, port1);
 
     /* Reset binding to vcpu0 when the channel is freed. */
     chn1->state          = ECS_FREE;
@@ -653,6 +664,11 @@ static void evtchn_set_pending(struct vcpu *v, int port)
     }
 }
 
+static void evtchn_clear_pending(struct domain *d, int port)
+{
+    clear_bit(port, &shared_info(d, evtchn_pending));
+}
+
 int guest_enabled_event(struct vcpu *v, uint32_t virq)
 {
     return ((v != NULL) && (v->virq_to_evtchn[virq] != 0));
@@ -1284,8 +1300,8 @@ static void domain_dump_evtchn_info(struct domain *d)
 
         printk("    %4u [%d/%d]: s=%d n=%d x=%d",
                port,
-               !!test_bit(port, &shared_info(d, evtchn_pending)),
-               !!test_bit(port, &shared_info(d, evtchn_mask)),
+               !!evtchn_is_pending(d, port),
+               !!evtchn_is_masked(d, port),
                chn->state, chn->notify_vcpu_id, chn->xen_consumer);
 
         switch ( chn->state )
diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c
index e9ef45f..def3bf6 100644
--- a/xen/common/keyhandler.c
+++ b/xen/common/keyhandler.c
@@ -302,10 +302,8 @@ static void dump_domains(unsigned char key)
             printk("Notifying guest %d:%d (virq %d, port %d, stat %d/%d/%d)\n",
                    d->domain_id, v->vcpu_id,
                    VIRQ_DEBUG, v->virq_to_evtchn[VIRQ_DEBUG],
-                   test_bit(v->virq_to_evtchn[VIRQ_DEBUG], 
-                            &shared_info(d, evtchn_pending)),
-                   test_bit(v->virq_to_evtchn[VIRQ_DEBUG], 
-                            &shared_info(d, evtchn_mask)),
+                   evtchn_is_pending(d, v->virq_to_evtchn[VIRQ_DEBUG]),
+                   evtchn_is_masked(d, v->virq_to_evtchn[VIRQ_DEBUG]),
                    test_bit(v->virq_to_evtchn[VIRQ_DEBUG] /
                             BITS_PER_EVTCHN_WORD(d),
                             &vcpu_info(v, evtchn_pending_sel)));
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index 22b8ffe..2e4a8d4 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -702,7 +702,7 @@ static long do_poll(struct sched_poll *sched_poll)
             goto out;
 
         rc = 0;
-        if ( test_bit(port, &shared_info(d, evtchn_pending)) )
+        if ( evtchn_is_pending(d, port) )
             goto out;
     }
 
diff --git a/xen/include/xen/event.h b/xen/include/xen/event.h
index c63b8b2..6912195 100644
--- a/xen/include/xen/event.h
+++ b/xen/include/xen/event.h
@@ -103,6 +103,12 @@ int evtchn_unmask(unsigned int port);
 /* Move all PIRQs after a vCPU was moved to another pCPU. */
 void evtchn_move_pirqs(struct vcpu *v);
 
+/* Tell a given event-channel port is pending or not */
+int evtchn_is_pending(struct domain *d, int port);
+
+/* Tell a given event-channel port is masked or not */
+int evtchn_is_masked(struct domain *d, int port);
+
 /* Allocate/free a Xen-attached event channel port. */
 typedef void (*xen_event_channel_notification_t)(
     struct vcpu *v, unsigned int port);
-- 
1.7.10.4