2 files changed, 91 insertions, 2 deletions

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index d71d2d2c341f..f5fae8b62bdf 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -92,6 +92,7 @@ static atomic64_t ap_bindings_complete_count = ATOMIC64_INIT(0);
 static DECLARE_COMPLETION(ap_init_apqn_bindings_complete);
 
 static struct ap_config_info *ap_qci_info;
+static struct ap_config_info *ap_qci_info_old;
 
 /*
  * AP bus related debug feature things.
@@ -229,9 +230,14 @@ static void __init ap_init_qci_info(void)
 	ap_qci_info = kzalloc(sizeof(*ap_qci_info), GFP_KERNEL);
 	if (!ap_qci_info)
 		return;
+	ap_qci_info_old = kzalloc(sizeof(*ap_qci_info_old), GFP_KERNEL);
+	if (!ap_qci_info_old)
+		return;
 	if (ap_fetch_qci_info(ap_qci_info) != 0) {
 		kfree(ap_qci_info);
+		kfree(ap_qci_info_old);
 		ap_qci_info = NULL;
+		ap_qci_info_old = NULL;
 		return;
 	}
 	AP_DBF_INFO("%s successful fetched initial qci info\n", __func__);
@@ -248,6 +254,8 @@ static void __init ap_init_qci_info(void)
 				    __func__, ap_max_domain_id);
 		}
 	}
+
+	memcpy(ap_qci_info_old, ap_qci_info, sizeof(*ap_qci_info));
 }
 
 /*
@@ -1630,6 +1638,49 @@ static int __match_queue_device_with_queue_id(struct device *dev, const void *da
 		&& AP_QID_QUEUE(to_ap_queue(dev)->qid) == (int)(long) data;
 }
 
+/* Helper function for notify_config_changed */
+static int __drv_notify_config_changed(struct device_driver *drv, void *data)
+{
+	struct ap_driver *ap_drv = to_ap_drv(drv);
+
+	if (try_module_get(drv->owner)) {
+		if (ap_drv->on_config_changed)
+			ap_drv->on_config_changed(ap_qci_info, ap_qci_info_old);
+		module_put(drv->owner);
+	}
+
+	return 0;
+}
+
+/* Notify all drivers about an qci config change */
+static inline void notify_config_changed(void)
+{
+	bus_for_each_drv(&ap_bus_type, NULL, NULL,
+			 __drv_notify_config_changed);
+}
+
+/* Helper function for notify_scan_complete */
+static int __drv_notify_scan_complete(struct device_driver *drv, void *data)
+{
+	struct ap_driver *ap_drv = to_ap_drv(drv);
+
+	if (try_module_get(drv->owner)) {
+		if (ap_drv->on_scan_complete)
+			ap_drv->on_scan_complete(ap_qci_info,
+						 ap_qci_info_old);
+		module_put(drv->owner);
+	}
+
+	return 0;
+}
+
+/* Notify all drivers about bus scan complete */
+static inline void notify_scan_complete(void)
+{
+	bus_for_each_drv(&ap_bus_type, NULL, NULL,
+			 __drv_notify_scan_complete);
+}
+
 /*
  * Helper function for ap_scan_bus().
  * Remove card device and associated queue devices.
@@ -1918,15 +1969,37 @@ static inline void ap_scan_adapter(int ap)
 }
 
 /**
+ * ap_get_configuration - get the host AP configuration
+ *
+ * Stores the host AP configuration information returned from the previous call
+ * to Query Configuration Information (QCI), then retrieves and stores the
+ * current AP configuration returned from QCI.
+ *
+ * Return: true if the host AP configuration changed between calls to QCI;
+ * otherwise, return false.
+ */
+static bool ap_get_configuration(void)
+{
+	memcpy(ap_qci_info_old, ap_qci_info, sizeof(*ap_qci_info));
+	ap_fetch_qci_info(ap_qci_info);
+
+	return memcmp(ap_qci_info, ap_qci_info_old,
+		      sizeof(struct ap_config_info)) != 0;
+}
+
+/**
  * ap_scan_bus(): Scan the AP bus for new devices
  * Runs periodically, workqueue timer (ap_config_time)
  * @unused: Unused pointer.
  */
 static void ap_scan_bus(struct work_struct *unused)
 {
-	int ap;
+	int ap, config_changed = 0;
 
-	ap_fetch_qci_info(ap_qci_info);
+	/* config change notify */
+	config_changed = ap_get_configuration();
+	if (config_changed)
+		notify_config_changed();
 	ap_select_domain();
 
 	AP_DBF_DBG("%s running\n", __func__);
@@ -1935,6 +2008,10 @@ static void ap_scan_bus(struct work_struct *unused)
 	for (ap = 0; ap <= ap_max_adapter_id; ap++)
 		ap_scan_adapter(ap);
 
+	/* scan complete notify */
+	if (config_changed)
+		notify_scan_complete();
+
 	/* check if there is at least one queue available with default domain */
 	if (ap_domain_index >= 0) {
 		struct device *dev =
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index 7dd992bad949..dc6f563e8787 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -144,6 +144,18 @@ struct ap_driver {
 	int (*probe)(struct ap_device *);
 	void (*remove)(struct ap_device *);
 	int (*in_use)(unsigned long *apm, unsigned long *aqm);
+	/*
+	 * Called at the start of the ap bus scan function when
+	 * the crypto config information (qci) has changed.
+	 */
+	void (*on_config_changed)(struct ap_config_info *new_config_info,
+				  struct ap_config_info *old_config_info);
+	/*
+	 * Called at the end of the ap bus scan function when
+	 * the crypto config information (qci) has changed.
+	 */
+	void (*on_scan_complete)(struct ap_config_info *new_config_info,
+				 struct ap_config_info *old_config_info);
 };
 
 #define to_ap_drv(x) container_of((x), struct ap_driver, driver)