ACPICA: Make it possible to enable runtime GPEs earlier

Runtime GPEs have corresponding _Lxx/_Exx methods and are enabled
automatically during the initialization of the ACPI subsystem through
acpi_update_all_gpes() with the assumption that acpi_setup_gpe_for_wake()
will be called in advance for all of the GPEs pointed to by _PRW
objects in the namespace that may be affected by acpi_update_all_gpes().
That is, acpi_ev_initialize_gpe_block() can only be called for a GPE
block after acpi_setup_gpe_for_wake() has been called for all of the
_PRW (wakeup) GPEs in it.

The platform firmware on some systems, however, expects GPEs to be
enabled before the enumeration of devices which is when
acpi_setup_gpe_for_wake() is called and that goes against the above
assumption.

For this reason, introduce a new flag to be set by
acpi_ev_initialize_gpe_block() when automatically enabling a GPE
to indicate to acpi_setup_gpe_for_wake() that it needs to drop the
reference to the GPE coming from acpi_ev_initialize_gpe_block()
and modify acpi_setup_gpe_for_wake() accordingly.  These changes
allow acpi_setup_gpe_for_wake() and acpi_ev_initialize_gpe_block()
to be invoked in any order.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/acpi/acpica/evgpeblk.c

@@ -496,6 +496,8 @@ acpi_ev_initialize_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
 				continue;
 			}
 
+			gpe_event_info->flags |= ACPI_GPE_AUTO_ENABLED;
+
 			if (event_status & ACPI_EVENT_FLAG_STATUS_SET) {
 				ACPI_INFO(("GPE 0x%02X active on init",
 					   gpe_number));

drivers/acpi/acpica/evxfgpe.c

@@ -435,6 +435,14 @@ acpi_setup_gpe_for_wake(acpi_handle wake_device,
 		 */
 		gpe_event_info->flags =
 		    (ACPI_GPE_DISPATCH_NOTIFY | ACPI_GPE_LEVEL_TRIGGERED);
+	} else if (gpe_event_info->flags & ACPI_GPE_AUTO_ENABLED) {
+		/*
+		 * A reference to this GPE has been added during the GPE block
+		 * initialization, so drop it now to prevent the GPE from being
+		 * permanently enabled and clear its ACPI_GPE_AUTO_ENABLED flag.
+		 */
+		(void)acpi_ev_remove_gpe_reference(gpe_event_info);
+		gpe_event_info->flags &= ~ACPI_GPE_AUTO_ENABLED;
 	}
 
 	/*

include/acpi/actypes.h

@@ -775,7 +775,7 @@ typedef u32 acpi_event_status;
  *   |  | | |  +-- Type of dispatch:to method, handler, notify, or none
  *   |  | | +----- Interrupt type: edge or level triggered
  *   |  | +------- Is a Wake GPE
- *   |  +--------- Is GPE masked by the software GPE masking mechanism
+ *   |  +--------- Has been enabled automatically at init time
  *   +------------ <Reserved>
  */
 #define ACPI_GPE_DISPATCH_NONE          (u8) 0x00
@@ -791,6 +791,7 @@ typedef u32 acpi_event_status;
 #define ACPI_GPE_XRUPT_TYPE_MASK        (u8) 0x08
 
 #define ACPI_GPE_CAN_WAKE               (u8) 0x10
+#define ACPI_GPE_AUTO_ENABLED           (u8) 0x20
 
 /*
  * Flags for GPE and Lock interfaces