ehea: Register memory hotplug, reboot and crash hooks on adapter probe

ehea creates memory hotplug, reboot and crash hooks even if there
are no adapters in the box. Just create them when we probe our
first adapter.

[cascardo: use ehea_register_memory_hooks return code]
Signed-off-by: Anton Blanchard <anton@samba.org>
Tested-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ehea/ehea_main.c

@@ -3262,6 +3262,139 @@ static void ehea_remove_device_sysfs(struct platform_device *dev)
 	device_remove_file(&dev->dev, &dev_attr_remove_port);
 }
 
+static int ehea_reboot_notifier(struct notifier_block *nb,
+				unsigned long action, void *unused)
+{
+	if (action == SYS_RESTART) {
+		pr_info("Reboot: freeing all eHEA resources\n");
+		ibmebus_unregister_driver(&ehea_driver);
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block ehea_reboot_nb = {
+	.notifier_call = ehea_reboot_notifier,
+};
+
+static int ehea_mem_notifier(struct notifier_block *nb,
+			     unsigned long action, void *data)
+{
+	int ret = NOTIFY_BAD;
+	struct memory_notify *arg = data;
+
+	mutex_lock(&dlpar_mem_lock);
+
+	switch (action) {
+	case MEM_CANCEL_OFFLINE:
+		pr_info("memory offlining canceled");
+		/* Fall through: re-add canceled memory block */
+
+	case MEM_ONLINE:
+		pr_info("memory is going online");
+		set_bit(__EHEA_STOP_XFER, &ehea_driver_flags);
+		if (ehea_add_sect_bmap(arg->start_pfn, arg->nr_pages))
+			goto out_unlock;
+		ehea_rereg_mrs();
+		break;
+
+	case MEM_GOING_OFFLINE:
+		pr_info("memory is going offline");
+		set_bit(__EHEA_STOP_XFER, &ehea_driver_flags);
+		if (ehea_rem_sect_bmap(arg->start_pfn, arg->nr_pages))
+			goto out_unlock;
+		ehea_rereg_mrs();
+		break;
+
+	default:
+		break;
+	}
+
+	ehea_update_firmware_handles();
+	ret = NOTIFY_OK;
+
+out_unlock:
+	mutex_unlock(&dlpar_mem_lock);
+	return ret;
+}
+
+static struct notifier_block ehea_mem_nb = {
+	.notifier_call = ehea_mem_notifier,
+};
+
+static void ehea_crash_handler(void)
+{
+	int i;
+
+	if (ehea_fw_handles.arr)
+		for (i = 0; i < ehea_fw_handles.num_entries; i++)
+			ehea_h_free_resource(ehea_fw_handles.arr[i].adh,
+					     ehea_fw_handles.arr[i].fwh,
+					     FORCE_FREE);
+
+	if (ehea_bcmc_regs.arr)
+		for (i = 0; i < ehea_bcmc_regs.num_entries; i++)
+			ehea_h_reg_dereg_bcmc(ehea_bcmc_regs.arr[i].adh,
+					      ehea_bcmc_regs.arr[i].port_id,
+					      ehea_bcmc_regs.arr[i].reg_type,
+					      ehea_bcmc_regs.arr[i].macaddr,
+					      0, H_DEREG_BCMC);
+}
+
+static atomic_t ehea_memory_hooks_registered;
+
+/* Register memory hooks on probe of first adapter */
+static int ehea_register_memory_hooks(void)
+{
+	int ret = 0;
+
+	if (atomic_inc_and_test(&ehea_memory_hooks_registered))
+		return 0;
+
+	ret = ehea_create_busmap();
+	if (ret) {
+		pr_info("ehea_create_busmap failed\n");
+		goto out;
+	}
+
+	ret = register_reboot_notifier(&ehea_reboot_nb);
+	if (ret) {
+		pr_info("register_reboot_notifier failed\n");
+		goto out;
+	}
+
+	ret = register_memory_notifier(&ehea_mem_nb);
+	if (ret) {
+		pr_info("register_memory_notifier failed\n");
+		goto out2;
+	}
+
+	ret = crash_shutdown_register(ehea_crash_handler);
+	if (ret) {
+		pr_info("crash_shutdown_register failed\n");
+		goto out3;
+	}
+
+	return 0;
+
+out3:
+	unregister_memory_notifier(&ehea_mem_nb);
+out2:
+	unregister_reboot_notifier(&ehea_reboot_nb);
+out:
+	return ret;
+}
+
+static void ehea_unregister_memory_hooks(void)
+{
+	if (atomic_read(&ehea_memory_hooks_registered))
+		return;
+
+	unregister_reboot_notifier(&ehea_reboot_nb);
+	if (crash_shutdown_unregister(ehea_crash_handler))
+		pr_info("failed unregistering crash handler\n");
+	unregister_memory_notifier(&ehea_mem_nb);
+}
+
 static int ehea_probe_adapter(struct platform_device *dev)
 {
 	struct ehea_adapter *adapter;
@@ -3269,6 +3402,10 @@ static int ehea_probe_adapter(struct platform_device *dev)
 	int ret;
 	int i;
 
+	ret = ehea_register_memory_hooks();
+	if (ret)
+		return ret;
+
 	if (!dev || !dev->dev.of_node) {
 		pr_err("Invalid ibmebus device probed\n");
 		return -EINVAL;
@@ -3392,81 +3529,6 @@ static int ehea_remove(struct platform_device *dev)
 	return 0;
 }
 
-static void ehea_crash_handler(void)
-{
-	int i;
-
-	if (ehea_fw_handles.arr)
-		for (i = 0; i < ehea_fw_handles.num_entries; i++)
-			ehea_h_free_resource(ehea_fw_handles.arr[i].adh,
-					     ehea_fw_handles.arr[i].fwh,
-					     FORCE_FREE);
-
-	if (ehea_bcmc_regs.arr)
-		for (i = 0; i < ehea_bcmc_regs.num_entries; i++)
-			ehea_h_reg_dereg_bcmc(ehea_bcmc_regs.arr[i].adh,
-					      ehea_bcmc_regs.arr[i].port_id,
-					      ehea_bcmc_regs.arr[i].reg_type,
-					      ehea_bcmc_regs.arr[i].macaddr,
-					      0, H_DEREG_BCMC);
-}
-
-static int ehea_mem_notifier(struct notifier_block *nb,
-                             unsigned long action, void *data)
-{
-	int ret = NOTIFY_BAD;
-	struct memory_notify *arg = data;
-
-	mutex_lock(&dlpar_mem_lock);
-
-	switch (action) {
-	case MEM_CANCEL_OFFLINE:
-		pr_info("memory offlining canceled");
-		/* Readd canceled memory block */
-	case MEM_ONLINE:
-		pr_info("memory is going online");
-		set_bit(__EHEA_STOP_XFER, &ehea_driver_flags);
-		if (ehea_add_sect_bmap(arg->start_pfn, arg->nr_pages))
-			goto out_unlock;
-		ehea_rereg_mrs();
-		break;
-	case MEM_GOING_OFFLINE:
-		pr_info("memory is going offline");
-		set_bit(__EHEA_STOP_XFER, &ehea_driver_flags);
-		if (ehea_rem_sect_bmap(arg->start_pfn, arg->nr_pages))
-			goto out_unlock;
-		ehea_rereg_mrs();
-		break;
-	default:
-		break;
-	}
-
-	ehea_update_firmware_handles();
-	ret = NOTIFY_OK;
-
-out_unlock:
-	mutex_unlock(&dlpar_mem_lock);
-	return ret;
-}
-
-static struct notifier_block ehea_mem_nb = {
-	.notifier_call = ehea_mem_notifier,
-};
-
-static int ehea_reboot_notifier(struct notifier_block *nb,
-				unsigned long action, void *unused)
-{
-	if (action == SYS_RESTART) {
-		pr_info("Reboot: freeing all eHEA resources\n");
-		ibmebus_unregister_driver(&ehea_driver);
-	}
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block ehea_reboot_nb = {
-	.notifier_call = ehea_reboot_notifier,
-};
-
 static int check_module_parm(void)
 {
 	int ret = 0;
@@ -3520,26 +3582,10 @@ static int __init ehea_module_init(void)
 	if (ret)
 		goto out;
 
-	ret = ehea_create_busmap();
-	if (ret)
-		goto out;
-
-	ret = register_reboot_notifier(&ehea_reboot_nb);
-	if (ret)
-		pr_info("failed registering reboot notifier\n");
-
-	ret = register_memory_notifier(&ehea_mem_nb);
-	if (ret)
-		pr_info("failed registering memory remove notifier\n");
-
-	ret = crash_shutdown_register(ehea_crash_handler);
-	if (ret)
-		pr_info("failed registering crash handler\n");
-
 	ret = ibmebus_register_driver(&ehea_driver);
 	if (ret) {
 		pr_err("failed registering eHEA device driver on ebus\n");
-		goto out2;
+		goto out;
 	}
 
 	ret = driver_create_file(&ehea_driver.driver,
@@ -3547,32 +3593,22 @@ static int __init ehea_module_init(void)
 	if (ret) {
 		pr_err("failed to register capabilities attribute, ret=%d\n",
 		       ret);
-		goto out3;
+		goto out2;
 	}
 
 	return ret;
 
-out3:
-	ibmebus_unregister_driver(&ehea_driver);
 out2:
-	unregister_memory_notifier(&ehea_mem_nb);
-	unregister_reboot_notifier(&ehea_reboot_nb);
-	crash_shutdown_unregister(ehea_crash_handler);
+	ibmebus_unregister_driver(&ehea_driver);
 out:
 	return ret;
 }
 
 static void __exit ehea_module_exit(void)
 {
-	int ret;
-
 	driver_remove_file(&ehea_driver.driver, &driver_attr_capabilities);
 	ibmebus_unregister_driver(&ehea_driver);
-	unregister_reboot_notifier(&ehea_reboot_nb);
-	ret = crash_shutdown_unregister(ehea_crash_handler);
-	if (ret)
-		pr_info("failed unregistering crash handler\n");
-	unregister_memory_notifier(&ehea_mem_nb);
+	ehea_unregister_memory_hooks();
 	kfree(ehea_fw_handles.arr);
 	kfree(ehea_bcmc_regs.arr);
 	ehea_destroy_busmap();