ACPICA: Events: Enhance acpi_ev_execute_reg_method() to ensure no _REG evaluations can happen during OS early boot stages

ACPICA commit 31178590dde82368fdb0f6b0e466b6c0add96c57

We can ensure no early _REG evaluations by ensuring the following rules in
acpi_ev_execute_reg_method():
1. If an address space handler is installed during early stage,
   _REG(CONNECT) evaluations are blocked. This is achieved using
   acpi_gbl_reg_methods_enabled which is renamed from
   acpi_gbl_reg_methods_executed.
2. If _REG(CONNECT) has never been evalauted for the region object,
   _REG(DISCONNECT) evaluations are blocked. This is achieved by a new
   region object flag: AOPOBJ_REG_CONNECTED.
Note that, after applying this patch, we can ensure _REG(DISCONNECT) is
always paired to _REG(CONNECT). Lv Zheng

Link: https://github.com/acpica/acpica/commit/31178590
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

7 files changed, 30 insertions, 42 deletions

diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index ef0abf4ef9ac..73462cac41d2 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -165,7 +165,7 @@ ACPI_GLOBAL(u8, acpi_gbl_next_owner_id_offset);
 
 /* Initialization sequencing */
 
-ACPI_GLOBAL(u8, acpi_gbl_reg_methods_executed);
+ACPI_INIT_GLOBAL(u8, acpi_gbl_reg_methods_enabled, FALSE);
 
 /* Misc */
 
diff --git a/drivers/acpi/acpica/acobject.h b/drivers/acpi/acpica/acobject.h
index 0bd02c4a5f75..2b154cfbe136 100644
--- a/drivers/acpi/acpica/acobject.h
+++ b/drivers/acpi/acpica/acobject.h
@@ -93,9 +93,10 @@
 #define AOPOBJ_AML_CONSTANT         0x01        /* Integer is an AML constant */
 #define AOPOBJ_STATIC_POINTER       0x02        /* Data is part of an ACPI table, don't delete */
 #define AOPOBJ_DATA_VALID           0x04        /* Object is initialized and data is valid */
-#define AOPOBJ_OBJECT_INITIALIZED   0x08        /* Region is initialized, _REG was run */
-#define AOPOBJ_SETUP_COMPLETE       0x10        /* Region setup is complete */
-#define AOPOBJ_INVALID              0x20        /* Host OS won't allow a Region address */
+#define AOPOBJ_OBJECT_INITIALIZED   0x08        /* Region is initialized */
+#define AOPOBJ_REG_CONNECTED        0x10        /* _REG was run */
+#define AOPOBJ_SETUP_COMPLETE       0x20        /* Region setup is complete */
+#define AOPOBJ_INVALID              0x40        /* Host OS won't allow a Region address */
 
 /******************************************************************************
  *
diff --git a/drivers/acpi/acpica/evregion.c b/drivers/acpi/acpica/evregion.c
index 432b81080369..cf6e8785491c 100644
--- a/drivers/acpi/acpica/evregion.c
+++ b/drivers/acpi/acpica/evregion.c
@@ -104,8 +104,6 @@ acpi_status acpi_ev_initialize_op_regions(void)
                 }
         }
 
-        acpi_gbl_reg_methods_executed = TRUE;
-
         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
         return_ACPI_STATUS(status);
 }
@@ -601,7 +599,18 @@ acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
                 return_ACPI_STATUS(AE_NOT_EXIST);
         }
 
-        if (region_obj2->extra.method_REG == NULL) {
+        if (region_obj2->extra.method_REG == NULL ||
+            region_obj->region.handler == NULL ||
+            !acpi_gbl_reg_methods_enabled) {
+                return_ACPI_STATUS(AE_OK);
+        }
+
+        /* _REG(DISCONNECT) should be paired with _REG(CONNECT) */
+
+        if ((function == ACPI_REG_CONNECT &&
+             region_obj->common.flags & AOPOBJ_REG_CONNECTED) ||
+            (function == ACPI_REG_DISCONNECT &&
+             !(region_obj->common.flags & AOPOBJ_REG_CONNECTED))) {
                 return_ACPI_STATUS(AE_OK);
         }
 
@@ -650,6 +659,16 @@ acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
         status = acpi_ns_evaluate(info);
         acpi_ut_remove_reference(args[1]);
 
+        if (ACPI_FAILURE(status)) {
+                goto cleanup2;
+        }
+
+        if (function == ACPI_REG_CONNECT) {
+                region_obj->common.flags |= AOPOBJ_REG_CONNECTED;
+        } else {
+                region_obj->common.flags &= ~AOPOBJ_REG_CONNECTED;
+        }
+
 cleanup2:
         acpi_ut_remove_reference(args[0]);
 
diff --git a/drivers/acpi/acpica/evxfregn.c b/drivers/acpi/acpica/evxfregn.c
index 3c905085fe5a..29f9f3999dfc 100644
--- a/drivers/acpi/acpica/evxfregn.c
+++ b/drivers/acpi/acpica/evxfregn.c
@@ -112,39 +112,6 @@ acpi_install_address_space_handler(acpi_handle device,
                 goto unlock_and_exit;
         }
 
-        /*
-         * For the default space_IDs, (the IDs for which there are default region handlers
-         * installed) Only execute the _REG methods if the global initialization _REG
-         * methods have already been run (via acpi_initialize_objects). In other words,
-         * we will defer the execution of the _REG methods for these space_IDs until
-         * execution of acpi_initialize_objects. This is done because we need the handlers
-         * for the default spaces (mem/io/pci/table) to be installed before we can run
-         * any control methods (or _REG methods). There is known BIOS code that depends
-         * on this.
-         *
-         * For all other space_IDs, we can safely execute the _REG methods immediately.
-         * This means that for IDs like embedded_controller, this function should be called
-         * only after acpi_enable_subsystem has been called.
-         */
-        switch (space_id) {
-        case ACPI_ADR_SPACE_SYSTEM_MEMORY:
-        case ACPI_ADR_SPACE_SYSTEM_IO:
-        case ACPI_ADR_SPACE_PCI_CONFIG:
-        case ACPI_ADR_SPACE_DATA_TABLE:
-
-                if (!acpi_gbl_reg_methods_executed) {
-
-                        /* We will defer execution of the _REG methods for this space */
-
-                        goto unlock_and_exit;
-                }
-                break;
-
-        default:
-
-                break;
-        }
-
         /* Run all _REG methods for this address space */
 
         status = acpi_ev_execute_reg_methods(node, space_id);
diff --git a/drivers/acpi/acpica/excreate.c b/drivers/acpi/acpica/excreate.c
index 6a1396e313b1..46be5a276863 100644
--- a/drivers/acpi/acpica/excreate.c
+++ b/drivers/acpi/acpica/excreate.c
@@ -345,7 +345,8 @@ acpi_ex_create_region(u8 * aml_start,
         obj_desc->region.node = node;
         obj_desc->region.handler = NULL;
         obj_desc->common.flags &=
-            ~(AOPOBJ_SETUP_COMPLETE | AOPOBJ_OBJECT_INITIALIZED);
+            ~(AOPOBJ_SETUP_COMPLETE | AOPOBJ_REG_CONNECTED |
+              AOPOBJ_OBJECT_INITIALIZED);
 
         /* Install the new region object in the parent Node */
 
diff --git a/drivers/acpi/acpica/utinit.c b/drivers/acpi/acpica/utinit.c
index ccd0745f011e..fd82a122785e 100644
--- a/drivers/acpi/acpica/utinit.c
+++ b/drivers/acpi/acpica/utinit.c
@@ -206,7 +206,6 @@ acpi_status acpi_ut_init_globals(void)
         acpi_gbl_next_owner_id_offset = 0;
         acpi_gbl_debugger_configuration = DEBUGGER_THREADING;
         acpi_gbl_osi_mutex = NULL;
-        acpi_gbl_reg_methods_executed = FALSE;
         acpi_gbl_max_loop_iterations = 0xFFFF;
 
         /* Hardware oriented */
diff --git a/drivers/acpi/acpica/utxfinit.c b/drivers/acpi/acpica/utxfinit.c
index 7d8eb602bbbe..1c7ed4986963 100644
--- a/drivers/acpi/acpica/utxfinit.c
+++ b/drivers/acpi/acpica/utxfinit.c
@@ -267,6 +267,7 @@ acpi_status __init acpi_initialize_objects(u32 flags)
          * initialized, even if they contain executable AML (see the call to
          * acpi_ns_initialize_objects below).
          */
+        acpi_gbl_reg_methods_enabled = TRUE;
         if (!(flags & ACPI_NO_ADDRESS_SPACE_INIT)) {
                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                   "[Init] Executing _REG OpRegion methods\n"));