ACPICA / Interpreter: Fix a regression triggered because of wrong Linux ECDT support

It is reported that the following commit triggers regressions:
 Linux commit: efaed9be998b5ae0afb7458e057e5f4402b43fa0
 ACPICA commit: 31178590dde82368fdb0f6b0e466b6c0add96c57
 Subject: ACPICA: Events: Enhance acpi_ev_execute_reg_method() to
          ensure no _REG evaluations can happen during OS early boot
          stages

This is because that the ECDT support is not corrected in Linux, and Linux
requires to execute _REG for ECDT (though this sounds so wrong), we need to
ensure acpi_gbl_namespace_initialized is set before ECDT probing in order
for _REG to be executed. Since we have to move
"acpi_gbl_namespace_initialized = TRUE" to the initialization step
happening before ECDT probing, acpi_load_tables() is the best candidate for
now. Thus this patch fixes the regression by doing so.

But if the ECDT support is fixed, Linux will not execute _REG for ECDT, and
ECDT probing will happen before acpi_load_tables(). At that time, we still
want to ensure acpi_gbl_namespace_initialized is set after executing
acpi_ns_initialize_objects() (under the condition of
acpi_gbl_group_module_level_code = FALSE), this patch also moves
acpi_ns_initialize_objects() to acpi_load_tables() accordingly.

Since acpi_ns_initialize_objects() doesn't seem to be skippable, this
patch also removes ACPI_NO_OBJECT_INIT for the one invoked in
acpi_load_tables(). And since the default region handlers should always be
installed before loading the tables, this patch also removes useless
acpi_gbl_group_module_level_code check accordingly. Reported by Chris
Bainbridge, Fixed by Lv Zheng.

Fixes: efaed9be998b (ACPICA: Events: Enhance acpi_ev_execute_reg_method() to ensure no _REG evaluations can happen during OS early boot stages)
Reported-and-tested-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 32 insertions, 39 deletions

diff --git a/drivers/acpi/acpica/nsinit.c b/drivers/acpi/acpica/nsinit.c
index f029a3da67eb..d4aa8b696ee9 100644
--- a/drivers/acpi/acpica/nsinit.c
+++ b/drivers/acpi/acpica/nsinit.c
@@ -84,6 +84,8 @@ acpi_status acpi_ns_initialize_objects(void)
 
         ACPI_FUNCTION_TRACE(ns_initialize_objects);
 
+        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
+                          "[Init] Completing Initialization of ACPI Objects\n"));
         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
                           "**** Starting initialization of namespace objects ****\n"));
         ACPI_DEBUG_PRINT_RAW((ACPI_DB_INIT,
diff --git a/drivers/acpi/acpica/tbxfload.c b/drivers/acpi/acpica/tbxfload.c
index 9496b84476a4..3151968c10d1 100644
--- a/drivers/acpi/acpica/tbxfload.c
+++ b/drivers/acpi/acpica/tbxfload.c
@@ -81,13 +81,11 @@ acpi_status __init acpi_load_tables(void)
          * between acpi_initialize_subsystem() and acpi_load_tables() to use
          * their customized default region handlers.
          */
-        if (acpi_gbl_group_module_level_code) {
-                status = acpi_ev_install_region_handlers();
-                if (ACPI_FAILURE(status) && status != AE_ALREADY_EXISTS) {
-                        ACPI_EXCEPTION((AE_INFO, status,
-                                        "During Region initialization"));
-                        return_ACPI_STATUS(status);
-                }
+        status = acpi_ev_install_region_handlers();
+        if (ACPI_FAILURE(status) && status != AE_ALREADY_EXISTS) {
+                ACPI_EXCEPTION((AE_INFO, status,
+                                "During Region initialization"));
+                return_ACPI_STATUS(status);
         }
 
         /* Load the namespace from the tables */
@@ -105,6 +103,20 @@ acpi_status __init acpi_load_tables(void)
                                 "While loading namespace from ACPI tables"));
         }
 
+        if (!acpi_gbl_group_module_level_code) {
+                /*
+                 * Initialize the objects that remain uninitialized. This
+                 * runs the executable AML that may be part of the
+                 * declaration of these objects:
+                 * operation_regions, buffer_fields, Buffers, and Packages.
+                 */
+                status = acpi_ns_initialize_objects();
+                if (ACPI_FAILURE(status)) {
+                        return_ACPI_STATUS(status);
+                }
+        }
+
+        acpi_gbl_namespace_initialized = TRUE;
         return_ACPI_STATUS(status);
 }
 
diff --git a/drivers/acpi/acpica/utxfinit.c b/drivers/acpi/acpica/utxfinit.c
index d70649d3ac60..75b5f27da267 100644
--- a/drivers/acpi/acpica/utxfinit.c
+++ b/drivers/acpi/acpica/utxfinit.c
@@ -154,23 +154,6 @@ acpi_status __init acpi_enable_subsystem(u32 flags)
          */
         acpi_gbl_early_initialization = FALSE;
 
-        /*
-         * Install the default operation region handlers. These are the
-         * handlers that are defined by the ACPI specification to be
-         * "always accessible" -- namely, system_memory, system_IO, and
-         * PCI_Config. This also means that no _REG methods need to be
-         * run for these address spaces. We need to have these handlers
-         * installed before any AML code can be executed, especially any
-         * module-level code (11/2015).
-         */
-        if (!acpi_gbl_group_module_level_code) {
-                status = acpi_ev_install_region_handlers();
-                if (ACPI_FAILURE(status)) {
-                        ACPI_EXCEPTION((AE_INFO, status,
-                                        "During Region initialization"));
-                        return_ACPI_STATUS(status);
-                }
-        }
 #if (!ACPI_REDUCED_HARDWARE)
 
         /* Enable ACPI mode */
@@ -284,25 +267,21 @@ acpi_status __init acpi_initialize_objects(u32 flags)
          */
         if (acpi_gbl_group_module_level_code) {
                 acpi_ns_exec_module_code_list();
-        }
 
-        /*
-         * Initialize the objects that remain uninitialized. This runs the
-         * executable AML that may be part of the declaration of these objects:
-         * operation_regions, buffer_fields, Buffers, and Packages.
-         */
-        if (!(flags & ACPI_NO_OBJECT_INIT)) {
-                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
-                                  "[Init] Completing Initialization of ACPI Objects\n"));
-
-                status = acpi_ns_initialize_objects();
-                if (ACPI_FAILURE(status)) {
-                        return_ACPI_STATUS(status);
+                /*
+                 * Initialize the objects that remain uninitialized. This
+                 * runs the executable AML that may be part of the
+                 * declaration of these objects:
+                 * operation_regions, buffer_fields, Buffers, and Packages.
+                 */
+                if (!(flags & ACPI_NO_OBJECT_INIT)) {
+                        status = acpi_ns_initialize_objects();
+                        if (ACPI_FAILURE(status)) {
+                                return_ACPI_STATUS(status);
+                        }
                 }
         }
 
-        acpi_gbl_namespace_initialized = TRUE;
-
         /*
          * Initialize all device/region objects in the namespace. This runs
          * the device _STA and _INI methods and region _REG methods.