ACPI: Add .setup() and .cleanup() callbacks to struct acpi_bus_type

Add two new callbacks,.setup() and .cleanup(), struct acpi_bus_type
and modify acpi_platform_notify() to call .setup() after executing
acpi_bind_one() successfully and acpi_platform_notify_remove() to
call .cleanup() before running acpi_unbind_one().  This will allow
the users of struct acpi_bus_type, PCI in particular, to specify
operations to be executed right after the given device has been
associated with a companion struct acpi_device and right before
it's going to be detached from that companion, respectively.

The main motivation is to be able to get rid of acpi_pci_bind()
and acpi_pci_unbind(), which are horrible horrible stuff.  [In short,
there are three problems with them: The way they populate the .bind()
and .unbind() callbacks of ACPI devices is rather less than
straightforward, they require special hotplug-specific paths to be
present in the ACPI namespace scanning code and by the time
acpi_pci_unbind() is called the PCI device object in question may
not exist any more.]

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>

2 files changed, 37 insertions, 15 deletions

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 01551840d236..ac00b882e75d 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -63,6 +63,9 @@ static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
 {
         struct acpi_bus_type *tmp, *ret = NULL;
 
+        if (!type)
+                return NULL;
+
         down_read(&bus_type_sem);
         list_for_each_entry(tmp, &bus_type_list, list) {
                 if (tmp->bus == type) {
@@ -264,28 +267,39 @@ static int acpi_platform_notify(struct device *dev)
 {
         struct acpi_bus_type *type;
         acpi_handle handle;
-        int ret = -EINVAL;
+        int ret;
 
         ret = acpi_bind_one(dev, NULL);
-        if (!ret)
-                goto out;
-
-        if (!dev->bus || !dev->parent) {
+        if (ret && (!dev->bus || !dev->parent)) {
                 /* bridge devices genernally haven't bus or parent */
                 ret = acpi_find_bridge_device(dev, &handle);
-                goto end;
+                if (!ret) {
+                        ret = acpi_bind_one(dev, handle);
+                        if (ret)
+                                goto out;
+                }
         }
+
         type = acpi_get_bus_type(dev->bus);
-        if (!type) {
-                DBG("No ACPI bus support for %s\n", dev_name(dev));
-                ret = -EINVAL;
-                goto end;
+        if (ret) {
+                if (!type || !type->find_device) {
+                        DBG("No ACPI bus support for %s\n", dev_name(dev));
+                        ret = -EINVAL;
+                        goto out;
+                }
+
+                ret = type->find_device(dev, &handle);
+                if (ret) {
+                        DBG("Unable to get handle for %s\n", dev_name(dev));
+                        goto out;
+                }
+                ret = acpi_bind_one(dev, handle);
+                if (ret)
+                        goto out;
         }
-        if ((ret = type->find_device(dev, &handle)) != 0)
-                DBG("Can't get handler for %s\n", dev_name(dev));
- end:
-        if (!ret)
-                acpi_bind_one(dev, handle);
+
+        if (type && type->setup)
+                type->setup(dev);
 
  out:
 #if ACPI_GLUE_DEBUG
@@ -304,6 +318,12 @@ static int acpi_platform_notify(struct device *dev)
 
 static int acpi_platform_notify_remove(struct device *dev)
 {
+        struct acpi_bus_type *type;
+
+        type = acpi_get_bus_type(dev->bus);
+        if (type && type->cleanup)
+                type->cleanup(dev);
+
         acpi_unbind_one(dev);
         return 0;
 }
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 5e1d5a1b477f..70647313a9bc 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -383,6 +383,8 @@ struct acpi_bus_type {
         int (*find_device) (struct device *, acpi_handle *);
         /* For bridges, such as PCI root bridge, IDE controller */
         int (*find_bridge) (struct device *, acpi_handle *);
+        void (*setup)(struct device *);
+        void (*cleanup)(struct device *);
 };
 int register_acpi_bus_type(struct acpi_bus_type *);
 int unregister_acpi_bus_type(struct acpi_bus_type *);