ACPICA: Make address_space_handler Install and _REG execution 2 separ…

…ate steps

ACPICA pull-req: acpica/acpica#786

ACPI-2.0 says that the EC op_region handler must be available immediately
(like the standard default op_region handlers):

Quoting from the ACPI spec version 6.3: "6.5.4 _REG (Region) ...
2. OSPM must make Embedded Controller operation regions, accessed via
the Embedded Controllers described in ECDT, available before executing
any control method. These operation regions may become inaccessible
after OSPM runs _REG(EmbeddedControl, 0)."

So the OS must probe the ECDT described EC and install the op_region handler
before calling acpi_enable_subsystem() and acpi_initialize_objects().

This is a problem because calling acpi_install_address_space_handler()
does not just install the op_region handler, it also runs the EC's _REG
method. This _REG method may rely on initialization done by the _INI
methods of one of the PCI / _SB root devices.

For the other early/default op_region handlers the op_region handler
install and the _REG execution is split into 2 separate steps:
1. acpi_ev_install_region_handlers(), called early from acpi_load_tables()
2. acpi_ev_initialize_op_regions(), called from acpi_initialize_objects()

To fix the EC op_region issue, add a new flags parameter to
acpi_install_address_space_handler() to allow doing things in
2 steps for other op_region handlers, like the EC handler, too.

To avoid having to modify all acpi_install_address_space_handler() callers,
the function is renamed to acpi_install_address_space_handler_flags() and
a static inline acpi_install_address_space_handler() is provided.

bug_link: https://bugzilla.kernel.org/show_bug.cgi?id=214899

Link: acpica/acpica@a44f29d0
Reported-and-tested-by: Johannes Penßel <johannespenssel@posteo.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by:  <hdegoede@redhat.com>

drivers/acpi/acpica/evxfregn.c

@@ -27,6 +27,7 @@ ACPI_MODULE_NAME("evxfregn")
  *              handler         - Address of the handler
  *              setup           - Address of the setup function
  *              context         - Value passed to the handler on each access
+ *              flags           - Flags
  *
  * RETURN:      Status
  *
@@ -37,13 +38,17 @@ ACPI_MODULE_NAME("evxfregn")
  * are executed here, and these methods can only be safely executed after
  * the default handlers have been installed and the hardware has been
  * initialized (via acpi_enable_subsystem.)
+ * To avoid this problem pass the ACPI_NO_EXEC__REG flag and
+ * later call this function again with ACPI_NO_INSTALL_SPACE_HANDLER to
+ * execute _REG.
  *
  ******************************************************************************/
 acpi_status
-acpi_install_address_space_handler(acpi_handle device,
-				   acpi_adr_space_type space_id,
-				   acpi_adr_space_handler handler,
-				   acpi_adr_space_setup setup, void *context)
+acpi_install_address_space_handler_flags(acpi_handle device,
+					 acpi_adr_space_type space_id,
+					 acpi_adr_space_handler handler,
+					 acpi_adr_space_setup setup,
+					 void *context, u32 flags)
 {
 	struct acpi_namespace_node *node;
 	acpi_status status;
@@ -71,23 +76,26 @@ acpi_install_address_space_handler(acpi_handle device,
 
 	/* Install the handler for all Regions for this Space ID */
 
-	status =
-	    acpi_ev_install_space_handler(node, space_id, handler, setup,
-					  context);
-	if (ACPI_FAILURE(status)) {
-		goto unlock_and_exit;
+	if (!(flags & ACPI_NO_INSTALL_SPACE_HANDLER)) {
+		status =
+		    acpi_ev_install_space_handler(node, space_id, handler,
+						  setup, context);
+		if (ACPI_FAILURE(status)) {
+			goto unlock_and_exit;
+		}
 	}
 
 	/* Run all _REG methods for this address space */
-
-	acpi_ev_execute_reg_methods(node, space_id, ACPI_REG_CONNECT);
+	if (!(flags & ACPI_NO_EXEC__REG)) {
+		acpi_ev_execute_reg_methods(node, space_id, ACPI_REG_CONNECT);
+	}
 
 unlock_and_exit:
 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 	return_ACPI_STATUS(status);
 }
 
-ACPI_EXPORT_SYMBOL(acpi_install_address_space_handler)
+ACPI_EXPORT_SYMBOL(acpi_install_address_space_handler_flags)
 
 /*******************************************************************************
  *

include/acpi/acpixf.h

@@ -643,15 +643,32 @@ ACPI_EXTERNAL_RETURN_STATUS(acpi_status
 							acpi_notify_handler
 							handler))
 ACPI_EXTERNAL_RETURN_STATUS(acpi_status
-			     acpi_install_address_space_handler(acpi_handle
-								device,
-								acpi_adr_space_type
-								space_id,
-								acpi_adr_space_handler
-								handler,
-								acpi_adr_space_setup
-								setup,
-								void *context))
+			    acpi_install_address_space_handler_flags(acpi_handle
+								     device,
+								     acpi_adr_space_type
+								     space_id,
+								     acpi_adr_space_handler
+								     handler,
+								     acpi_adr_space_setup
+								     setup,
+								     void
+								     *context,
+								     u32 flags))
+static ACPI_INLINE acpi_status acpi_install_address_space_handler(acpi_handle
+								  device,
+								  acpi_adr_space_type
+								  space_id,
+								  acpi_adr_space_handler
+								  handler,
+								  acpi_adr_space_setup
+								  setup,
+								  void *context)
+{
+	return acpi_install_address_space_handler_flags(device, space_id,
+							handler, setup, context,
+							ACPI_FULL_INITIALIZATION);
+}
+
 ACPI_EXTERNAL_RETURN_STATUS(acpi_status
 			     acpi_remove_address_space_handler(acpi_handle
 							       device,

include/acpi/actypes.h

@@ -566,6 +566,8 @@ typedef u64 acpi_integer;
 #define ACPI_NO_OBJECT_INIT             0x0020
 #define ACPI_NO_DEVICE_INIT             0x0040
 #define ACPI_NO_ADDRESS_SPACE_INIT      0x0080
+#define ACPI_NO_INSTALL_SPACE_HANDLER   0x0100
+#define ACPI_NO_EXEC__REG               0x0200
 
 /*
  * Initialization state