[PATCH 2/2] ACPI / scan: Simplify container driver

["Rafael J. Wysocki" <rjw@sisk.pl>]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The only useful thing that the ACPI container driver does is to
install system notify handlers for all container and module device
objects it finds in the namespace.  The driver structure,
acpi_container_driver, and the data structures created by its
.add() callback are in fact not used by the driver, so remove
them entirely.

It also makes a little sense to build that driver as a module,
so make it non-modular and add its initialization to the
namespace scanning code.

In addition to that, make the namespace walk callback used for
installing the notify handlers more straightforward.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/Kconfig     |    2 
 drivers/acpi/container.c |  158 ++++++-----------------------------------------
 drivers/acpi/internal.h  |    5 +
 drivers/acpi/scan.c      |    1 
 4 files changed, 30 insertions(+), 136 deletions(-)

Index: test/drivers/acpi/container.c
===================================================================
--- test.orig/drivers/acpi/container.c
+++ test/drivers/acpi/container.c
@@ -38,41 +38,15 @@
 
 #define PREFIX "ACPI: "
 
-#define ACPI_CONTAINER_DEVICE_NAME	"ACPI container device"
-#define ACPI_CONTAINER_CLASS		"container"
-
-#define INSTALL_NOTIFY_HANDLER		1
-#define UNINSTALL_NOTIFY_HANDLER	2
-
 #define _COMPONENT			ACPI_CONTAINER_COMPONENT
 ACPI_MODULE_NAME("container");
 
-MODULE_AUTHOR("Anil S Keshavamurthy");
-MODULE_DESCRIPTION("ACPI container driver");
-MODULE_LICENSE("GPL");
-
-static int acpi_container_add(struct acpi_device *device);
-static int acpi_container_remove(struct acpi_device *device);
-
 static const struct acpi_device_id container_device_ids[] = {
 	{"ACPI0004", 0},
 	{"PNP0A05", 0},
 	{"PNP0A06", 0},
 	{"", 0},
 };
-MODULE_DEVICE_TABLE(acpi, container_device_ids);
-
-static struct acpi_driver acpi_container_driver = {
-	.name = "container",
-	.class = ACPI_CONTAINER_CLASS,
-	.ids = container_device_ids,
-	.ops = {
-		.add = acpi_container_add,
-		.remove = acpi_container_remove,
-		},
-};
-
-/*******************************************************************/
 
 static int is_device_present(acpi_handle handle)
 {
@@ -92,49 +66,6 @@ static int is_device_present(acpi_handle
 	return ((sta & ACPI_STA_DEVICE_PRESENT) == ACPI_STA_DEVICE_PRESENT);
 }
 
-static bool is_container_device(const char *hid)
-{
-	const struct acpi_device_id *container_id;
-
-	for (container_id = container_device_ids;
-	     container_id->id[0]; container_id++) {
-		if (!strcmp((char *)container_id->id, hid))
-			return true;
-	}
-
-	return false;
-}
-
-/*******************************************************************/
-static int acpi_container_add(struct acpi_device *device)
-{
-	struct acpi_container *container;
-
-	container = kzalloc(sizeof(struct acpi_container), GFP_KERNEL);
-	if (!container)
-		return -ENOMEM;
-
-	container->handle = device->handle;
-	strcpy(acpi_device_name(device), ACPI_CONTAINER_DEVICE_NAME);
-	strcpy(acpi_device_class(device), ACPI_CONTAINER_CLASS);
-	device->driver_data = container;
-
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device <%s> bid <%s>\n",
-			  acpi_device_name(device), acpi_device_bid(device)));
-
-	return 0;
-}
-
-static int acpi_container_remove(struct acpi_device *device)
-{
-	acpi_status status = AE_OK;
-	struct acpi_container *pc = NULL;
-
-	pc = acpi_driver_data(device);
-	kfree(pc);
-	return status;
-}
-
 static void container_notify_cb(acpi_handle handle, u32 type, void *context)
 {
 	struct acpi_device *device = NULL;
@@ -199,84 +130,41 @@ static void container_notify_cb(acpi_han
 	return;
 }
 
-static acpi_status
-container_walk_namespace_cb(acpi_handle handle,
-			    u32 lvl, void *context, void **rv)
+static bool is_container(acpi_handle handle)
 {
-	char *hid = NULL;
 	struct acpi_device_info *info;
-	acpi_status status;
-	int *action = context;
+	bool ret = false;
 
-	status = acpi_get_object_info(handle, &info);
-	if (ACPI_FAILURE(status)) {
-		return AE_OK;
-	}
-
-	if (info->valid & ACPI_VALID_HID)
-		hid = info->hardware_id.string;
-
-	if (hid == NULL) {
-		goto end;
-	}
+	if (ACPI_FAILURE(acpi_get_object_info(handle, &info)))
+		return false;
 
-	if (!is_container_device(hid))
-		goto end;
+	if (info->valid & ACPI_VALID_HID) {
+		const struct acpi_device_id *id;
 
-	switch (*action) {
-	case INSTALL_NOTIFY_HANDLER:
-		acpi_install_notify_handler(handle,
-					    ACPI_SYSTEM_NOTIFY,
-					    container_notify_cb, NULL);
-		break;
-	case UNINSTALL_NOTIFY_HANDLER:
-		acpi_remove_notify_handler(handle,
-					   ACPI_SYSTEM_NOTIFY,
-					   container_notify_cb);
-		break;
-	default:
-		break;
+		for (id = container_device_ids; id->id[0]; id++) {
+			ret = !strcmp((char *)id->id, info->hardware_id.string);
+			if (ret)
+				break;
+		}
 	}
-
-      end:
 	kfree(info);
-
-	return AE_OK;
+	return ret;
 }
 
-static int __init acpi_container_init(void)
+static acpi_status acpi_container_register_notify_handler(acpi_handle handle,
+							  u32 lvl, void *ctxt,
+							  void **retv)
 {
-	int result = 0;
-	int action = INSTALL_NOTIFY_HANDLER;
-
-	result = acpi_bus_register_driver(&acpi_container_driver);
-	if (result < 0) {
-		return (result);
-	}
-
-	/* register notify handler to every container device */
-	acpi_walk_namespace(ACPI_TYPE_DEVICE,
-			    ACPI_ROOT_OBJECT,
-			    ACPI_UINT32_MAX,
-			    container_walk_namespace_cb, NULL, &action, NULL);
+	if (is_container(handle))
+		acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+					    container_notify_cb, NULL);
 
-	return (0);
+	return AE_OK;
 }
 
-static void __exit acpi_container_exit(void)
+void __init acpi_container_init(void)
 {
-	int action = UNINSTALL_NOTIFY_HANDLER;
-
-
-	acpi_walk_namespace(ACPI_TYPE_DEVICE,
-			    ACPI_ROOT_OBJECT,
-			    ACPI_UINT32_MAX,
-			    container_walk_namespace_cb, NULL, &action, NULL);
-
-	acpi_bus_unregister_driver(&acpi_container_driver);
-
-	return;
+	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,
+			    acpi_container_register_notify_handler, NULL,
+			    NULL, NULL);
 }
-
-module_init(acpi_container_init);
-module_exit(acpi_container_exit);
Index: test/drivers/acpi/Kconfig
===================================================================
--- test.orig/drivers/acpi/Kconfig
+++ test/drivers/acpi/Kconfig
@@ -334,7 +334,7 @@ config X86_PM_TIMER
 	  systems require this timer. 
 
 config ACPI_CONTAINER
-	tristate "Container and Module Devices (EXPERIMENTAL)"
+	bool "Container and Module Devices (EXPERIMENTAL)"
 	depends on EXPERIMENTAL
 	default (ACPI_HOTPLUG_MEMORY || ACPI_HOTPLUG_CPU || ACPI_HOTPLUG_IO)
 	help
Index: test/drivers/acpi/internal.h
===================================================================
--- test.orig/drivers/acpi/internal.h
+++ test/drivers/acpi/internal.h
@@ -40,6 +40,11 @@ void acpi_memory_hotplug_init(void);
 #else
 static inline void acpi_memory_hotplug_init(void) {}
 #endif
+#ifdef ACPI_CONTAINER
+void acpi_container_init(void);
+#else
+static inline void acpi_container_init(void) {}
+#endif
 
 #ifdef CONFIG_DEBUG_FS
 extern struct dentry *acpi_debugfs_dir;
Index: test/drivers/acpi/scan.c
===================================================================
--- test.orig/drivers/acpi/scan.c
+++ test/drivers/acpi/scan.c
@@ -1763,6 +1763,7 @@ int __init acpi_scan_init(void)
 	acpi_platform_init();
 	acpi_csrt_init();
 	acpi_memory_hotplug_init();
+	acpi_container_init();
 
 	/*
 	 * Enumerate devices in the ACPI namespace.