[RFC PATCH 08/12] arm/sdei: add support to register interrupt bind notifier

[Heyi Guo <guoheyi@huawei.com>]

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 <guoheyi@huawei.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
---
 target/arm/sdei.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 target/arm/sdei.h | 17 +++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/target/arm/sdei.c b/target/arm/sdei.c
index 9ceb131..efdb681 100644
--- a/target/arm/sdei.c
+++ b/target/arm/sdei.c
@@ -45,6 +45,52 @@
 
 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;
@@ -502,6 +548,7 @@ 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);
@@ -522,6 +569,7 @@ static int32_t sdei_free_event_num_locked(QemuSDEState *s, QemuSDEProp *prop)
         goto unlock_return;
     }
 
+    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;
@@ -1331,6 +1379,7 @@ static int qemu_sdei_post_load(void *opaque, int version_id)
         int intid = sde_props[i].interrupt;
         if (intid != SDEI_INVALID_INTERRUPT) {
             s->irq_map[intid] = sde_props[i].event_id;
+            sdei_notify_bind(intid, sde_props[i].event_id, true);
             override_qemu_irq(s, sde_props[i].event_id, intid);
         }
     }
diff --git a/target/arm/sdei.h b/target/arm/sdei.h
index a61e788..feaaf1a 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 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
-- 
1.8.3.1