[RFC v2 10/14] arm/sdei: add support to register interrupt bind notifier

[Heyi Guo]

Other qemu modules related with the interrupt bind operation may want
to be notified when guest requests to bind interrupt to sdei event, so
we add register and unregister interfaces.

Signed-off-by: Heyi Guo <address@hidden>
Cc: Peter Maydell <address@hidden>
Cc: Dave Martin <address@hidden>
Cc: Marc Zyngier <address@hidden>
Cc: Mark Rutland <address@hidden>
Cc: James Morse <address@hidden>
---
 target/arm/sdei.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++
 target/arm/sdei.h | 17 +++++++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/target/arm/sdei.c b/target/arm/sdei.c
index 529a06c1f6..4cc68e4acf 100644
--- a/target/arm/sdei.c
+++ b/target/arm/sdei.c
@@ -48,6 +48,52 @@
 
 static QemuSDEState *sde_state;
 
+typedef struct QemuSDEIBindNotifyEntry {
+    QTAILQ_ENTRY(QemuSDEIBindNotifyEntry) entry;
+    QemuSDEIBindNotify *func;
+    void *opaque;
+    int irq;
+} QemuSDEIBindNotifyEntry;
+
+static QTAILQ_HEAD(, QemuSDEIBindNotifyEntry) bind_notifiers =
+    QTAILQ_HEAD_INITIALIZER(bind_notifiers);
+
+void qemu_register_sdei_bind_notifier(QemuSDEIBindNotify *func,
+                                      void *opaque, int irq)
+{
+    QemuSDEIBindNotifyEntry *be = g_new0(QemuSDEIBindNotifyEntry, 1);
+
+    be->func = func;
+    be->opaque = opaque;
+    be->irq = irq;
+    QTAILQ_INSERT_TAIL(&bind_notifiers, be, entry);
+}
+
+void qemu_unregister_sdei_bind_notifier(QemuSDEIBindNotify *func,
+                                        void *opaque, int irq)
+{
+    QemuSDEIBindNotifyEntry *be;
+
+    QTAILQ_FOREACH(be, &bind_notifiers, entry) {
+        if (be->func == func && be->opaque == opaque && be->irq == irq) {
+            QTAILQ_REMOVE(&bind_notifiers, be, entry);
+            g_free(be);
+            return;
+        }
+    }
+}
+
+static void sdei_notify_bind(int irq, int32_t event, bool bind)
+{
+    QemuSDEIBindNotifyEntry *be, *nbe;
+
+    QTAILQ_FOREACH_SAFE(be, &bind_notifiers, entry, nbe) {
+        if (be->irq == irq) {
+            be->func(be->opaque, irq, event, bind);
+        }
+    }
+}
+
 static void qemu_sde_prop_init(QemuSDEState *s)
 {
     QemuSDEProp *sde_props = s->sde_props_state;
@@ -529,6 +575,7 @@ static int32_t sdei_alloc_event_num(QemuSDEState *s, bool 
is_critical,
             sde_props[index].interrupt = intid;
             sde_props[index].is_shared = is_shared;
             sde_props[index].is_critical = is_critical;
+            sdei_notify_bind(intid, event, true);
             override_qemu_irq(s, event, intid);
             s->irq_map[intid] = event;
             qemu_mutex_unlock(&sde_props[index].lock);
@@ -547,6 +594,7 @@ static int32_t sdei_free_event_num_locked(QemuSDEState *s, 
QemuSDEProp *prop)
         return SDEI_DENIED;
     }
 
+    sdei_notify_bind(prop->interrupt, prop->event_id, false);
     restore_qemu_irq(s, prop->event_id, prop->interrupt);
     s->irq_map[prop->interrupt] = SDEI_INVALID_EVENT_ID;
     prop->event_id = SDEI_INVALID_EVENT_ID;
diff --git a/target/arm/sdei.h b/target/arm/sdei.h
index 5ecc32d667..9c15cf3186 100644
--- a/target/arm/sdei.h
+++ b/target/arm/sdei.h
@@ -38,4 +38,21 @@ void sdei_handle_request(CPUState *cs, struct kvm_run *run);
  */
 bool trigger_sdei_by_irq(int cpu, int irq);
 
+/*
+ * Notify callback prototype; the argument "bind" tells whether it is a bind
+ * operation or unbind one.
+ */
+typedef void QemuSDEIBindNotify(void *opaque, int irq,
+                                int32_t event, bool bind);
+/*
+ * Register a notify callback for a specific interrupt bind operation; the
+ * client will be both notified by bind and unbind operation.
+ */
+void qemu_register_sdei_bind_notifier(QemuSDEIBindNotify *func,
+                                      void *opaque, int irq);
+/*
+ * Unregister a notify callback for a specific interrupt bind operation.
+ */
+void qemu_unregister_sdei_bind_notifier(QemuSDEIBindNotify *func,
+                                        void *opaque, int irq);
 #endif
-- 
2.19.1