ACPI / scan: Introduce common code for ACPI-based device hotplug

Multiple drivers handling hotplug-capable ACPI device nodes install
notify handlers covering the same types of events in a very similar
way.  Moreover, those handlers are installed in separate namespace
walks, although that really should be done during namespace scans
carried out by acpi_bus_scan().  This leads to substantial code
duplication, unnecessary overhead and behavior that is hard to
follow.

For this reason, introduce common code in drivers/acpi/scan.c for
handling hotplug-related notification and carrying out device
insertion and eject operations in a generic fashion, such that it
may be used by all of the relevant drivers in the future.  To cover
the existing differences between those drivers introduce struct
acpi_hotplug_profile for representing collections of hotplug
settings associated with different ACPI scan handlers that can be
used by the drivers to make the common code reflect their current
behavior.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index e65278f560c4..f2c1d08a4798 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -88,11 +88,23 @@ struct acpi_device;
  * -----------------
  */
 
+enum acpi_hotplug_mode {
+        AHM_GENERIC = 0,
+        AHM_CONTAINER,
+        AHM_COUNT
+};
+
+struct acpi_hotplug_profile {
+        bool enabled:1;
+        enum acpi_hotplug_mode mode;
+};
+
 struct acpi_scan_handler {
         const struct acpi_device_id *ids;
         struct list_head list_node;
         int (*attach)(struct acpi_device *dev, const struct acpi_device_id *id);
         void (*detach)(struct acpi_device *dev);
+        struct acpi_hotplug_profile hotplug;
 };
 
 /*