1 files changed, 148 insertions, 7 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 5f28cf778349..ad9fc84a8601 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -46,6 +46,13 @@ DEFINE_MUTEX(acpi_device_lock);
 LIST_HEAD(acpi_wakeup_device_list);
 static DEFINE_MUTEX(acpi_hp_context_lock);
 
+/*
+ * The UART device described by the SPCR table is the only object which needs
+ * special-casing. Everything else is covered by ACPI namespace paths in STAO
+ * table.
+ */
+static u64 spcr_uart_addr;
+
 struct acpi_dep_data {
 	struct list_head node;
 	acpi_handle master;
@@ -494,6 +501,8 @@ static void acpi_device_del(struct acpi_device *device)
 	device_del(&device->dev);
 }
 
+static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
+
 static LIST_HEAD(acpi_device_del_list);
 static DEFINE_MUTEX(acpi_device_del_lock);
 
@@ -514,6 +523,9 @@ static void acpi_device_del_work_fn(struct work_struct *work_not_used)
 
 		mutex_unlock(&acpi_device_del_lock);
 
+		blocking_notifier_call_chain(&acpi_reconfig_chain,
+					     ACPI_RECONFIG_DEVICE_REMOVE, adev);
+
 		acpi_device_del(adev);
 		/*
 		 * Drop references to all power resources that might have been
@@ -1406,7 +1418,7 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
 	acpi_bus_get_flags(device);
 	device->flags.match_driver = false;
 	device->flags.initialized = true;
-	device->flags.visited = false;
+	acpi_device_clear_enumerated(device);
 	device_initialize(&device->dev);
 	dev_set_uevent_suppress(&device->dev, true);
 	acpi_init_coherency(device);
@@ -1453,6 +1465,41 @@ static int acpi_add_single_object(struct acpi_device **child,
 	return 0;
 }
 
+static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
+					    void *context)
+{
+	struct resource *res = context;
+
+	if (acpi_dev_resource_memory(ares, res))
+		return AE_CTRL_TERMINATE;
+
+	return AE_OK;
+}
+
+static bool acpi_device_should_be_hidden(acpi_handle handle)
+{
+	acpi_status status;
+	struct resource res;
+
+	/* Check if it should ignore the UART device */
+	if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
+		return false;
+
+	/*
+	 * The UART device described in SPCR table is assumed to have only one
+	 * memory resource present. So we only look for the first one here.
+	 */
+	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+				     acpi_get_resource_memory, &res);
+	if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
+		return false;
+
+	acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
+			 &res.start);
+
+	return true;
+}
+
 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
 				    unsigned long long *sta)
 {
@@ -1466,6 +1513,9 @@ static int acpi_bus_type_and_status(acpi_handle handle, int *type,
 	switch (acpi_type) {
 	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */
 	case ACPI_TYPE_DEVICE:
+		if (acpi_device_should_be_hidden(handle))
+			return -ENODEV;
+
 		*type = ACPI_BUS_TYPE_DEVICE;
 		status = acpi_bus_get_status_handle(handle, sta);
 		if (ACPI_FAILURE(status))
@@ -1676,15 +1726,20 @@ static void acpi_default_enumeration(struct acpi_device *device)
 	bool is_spi_i2c_slave = false;
 
 	/*
-	 * Do not enemerate SPI/I2C slaves as they will be enuerated by their
+	 * Do not enumerate SPI/I2C slaves as they will be enumerated by their
 	 * respective parents.
 	 */
 	INIT_LIST_HEAD(&resource_list);
 	acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
 			       &is_spi_i2c_slave);
 	acpi_dev_free_resource_list(&resource_list);
-	if (!is_spi_i2c_slave)
+	if (!is_spi_i2c_slave) {
 		acpi_create_platform_device(device);
+		acpi_device_set_enumerated(device);
+	} else {
+		blocking_notifier_call_chain(&acpi_reconfig_chain,
+					     ACPI_RECONFIG_DEVICE_ADD, device);
+	}
 }
 
 static const struct acpi_device_id generic_device_ids[] = {
@@ -1751,7 +1806,7 @@ static void acpi_bus_attach(struct acpi_device *device)
 	acpi_bus_get_status(device);
 	/* Skip devices that are not present. */
 	if (!acpi_device_is_present(device)) {
-		device->flags.visited = false;
+		acpi_device_clear_enumerated(device);
 		device->flags.power_manageable = 0;
 		return;
 	}
@@ -1766,7 +1821,7 @@ static void acpi_bus_attach(struct acpi_device *device)
 
 		device->flags.initialized = true;
 	}
-	device->flags.visited = false;
+
 	ret = acpi_scan_attach_handler(device);
 	if (ret < 0)
 		return;
@@ -1780,7 +1835,6 @@ static void acpi_bus_attach(struct acpi_device *device)
 		if (!ret && device->pnp.type.platform_id)
 			acpi_default_enumeration(device);
 	}
-	device->flags.visited = true;
 
  ok:
 	list_for_each_entry(child, &device->children, node)
@@ -1872,7 +1926,7 @@ void acpi_bus_trim(struct acpi_device *adev)
 	 */
 	acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
 	adev->flags.initialized = false;
-	adev->flags.visited = false;
+	acpi_device_clear_enumerated(adev);
 }
 EXPORT_SYMBOL_GPL(acpi_bus_trim);
 
@@ -1916,9 +1970,26 @@ static int acpi_bus_scan_fixed(void)
 	return result < 0 ? result : 0;
 }
 
+static void __init acpi_get_spcr_uart_addr(void)
+{
+	acpi_status status;
+	struct acpi_table_spcr *spcr_ptr;
+
+	status = acpi_get_table(ACPI_SIG_SPCR, 0,
+				(struct acpi_table_header **)&spcr_ptr);
+	if (ACPI_SUCCESS(status))
+		spcr_uart_addr = spcr_ptr->serial_port.address;
+	else
+		printk(KERN_WARNING PREFIX "STAO table present, but SPCR is missing\n");
+}
+
+static bool acpi_scan_initialized;
+
 int __init acpi_scan_init(void)
 {
 	int result;
+	acpi_status status;
+	struct acpi_table_stao *stao_ptr;
 
 	acpi_pci_root_init();
 	acpi_pci_link_init();
@@ -1934,6 +2005,20 @@ int __init acpi_scan_init(void)
 
 	acpi_scan_add_handler(&generic_device_handler);
 
+	/*
+	 * If there is STAO table, check whether it needs to ignore the UART
+	 * device in SPCR table.
+	 */
+	status = acpi_get_table(ACPI_SIG_STAO, 0,
+				(struct acpi_table_header **)&stao_ptr);
+	if (ACPI_SUCCESS(status)) {
+		if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
+			printk(KERN_INFO PREFIX "STAO Name List not yet supported.");
+
+		if (stao_ptr->ignore_uart)
+			acpi_get_spcr_uart_addr();
+	}
+
 	mutex_lock(&acpi_scan_lock);
 	/*
 	 * Enumerate devices in the ACPI namespace.
@@ -1960,6 +2045,8 @@ int __init acpi_scan_init(void)
 
 	acpi_update_all_gpes();
 
+	acpi_scan_initialized = true;
+
  out:
 	mutex_unlock(&acpi_scan_lock);
 	return result;
@@ -2003,3 +2090,57 @@ int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
 
 	return count;
 }
+
+struct acpi_table_events_work {
+	struct work_struct work;
+	void *table;
+	u32 event;
+};
+
+static void acpi_table_events_fn(struct work_struct *work)
+{
+	struct acpi_table_events_work *tew;
+
+	tew = container_of(work, struct acpi_table_events_work, work);
+
+	if (tew->event == ACPI_TABLE_EVENT_LOAD) {
+		acpi_scan_lock_acquire();
+		acpi_bus_scan(ACPI_ROOT_OBJECT);
+		acpi_scan_lock_release();
+	}
+
+	kfree(tew);
+}
+
+void acpi_scan_table_handler(u32 event, void *table, void *context)
+{
+	struct acpi_table_events_work *tew;
+
+	if (!acpi_scan_initialized)
+		return;
+
+	if (event != ACPI_TABLE_EVENT_LOAD)
+		return;
+
+	tew = kmalloc(sizeof(*tew), GFP_KERNEL);
+	if (!tew)
+		return;
+
+	INIT_WORK(&tew->work, acpi_table_events_fn);
+	tew->table = table;
+	tew->event = event;
+
+	schedule_work(&tew->work);
+}
+
+int acpi_reconfig_notifier_register(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
+}
+EXPORT_SYMBOL(acpi_reconfig_notifier_register);
+
+int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
+}
+EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);