[PATCH 29/30] ACPICA: Namespace: Reorder \_SB._INI to make sure it is evaluated before _REG evaluations

[Lv Zheng]

ACPICA commit f005ee6b90d152c1f499efcca6b771a93903cb55

This patch splits \_SB._INI evaluation from device initialization code, so
that it can be performed before PCI_Config _REG evaluations. This is
required for the device enumeration process. Some named objects are
initialized in \_SB._INI and PCI_Config _REG evaluations may use
uninitialized named objects because of the order issue.

This must be fixed before fixing ECDT order issue. There are existing
tables allowing ECDT EC to be used for the entire device enumeration
process, but the enabling of ECDT EC is done in \_SB._INI. Thus \_SB._INI
must be the first control method evaluated in the device enumeration
process. Normally, the order should be automatically ensured by the device
enumeration process itself (for example, PCI_Config _REGs are evaluated by
the PCI bus driver when the driver is probed by the enumeration process),
but since the process is split on Linux (partially done in Linux, partially
done in ACPICA), we need to ensure this with special logics in order to be
regression safe. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/f005ee6b
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx>
---
 drivers/acpi/acpica/nsinit.c |   75 ++++++++++++++++++++++++++++++------------
 1 file changed, 54 insertions(+), 21 deletions(-)

diff --git a/drivers/acpi/acpica/nsinit.c b/drivers/acpi/acpica/nsinit.c
index 2de8adb..36643a8 100644
--- a/drivers/acpi/acpica/nsinit.c
+++ b/drivers/acpi/acpica/nsinit.c
@@ -140,6 +140,7 @@ acpi_status acpi_ns_initialize_devices(u32 flags)
 {
 	acpi_status status = AE_OK;
 	struct acpi_device_walk_info info;
+	acpi_handle handle;
 
 	ACPI_FUNCTION_TRACE(ns_initialize_devices);
 
@@ -190,6 +191,27 @@ acpi_status acpi_ns_initialize_devices(u32 flags)
 		if (ACPI_SUCCESS(status)) {
 			info.num_INI++;
 		}
+
+		/*
+		 * Execute \_SB._INI.
+		 * There appears to be a strict order requirement for \_SB._INI,
+		 * which should be evaluated before any _REG evaluations.
+		 */
+		status = acpi_get_handle(NULL, "\\_SB", &handle);
+		if (ACPI_SUCCESS(status)) {
+			memset(info.evaluate_info, 0,
+			       sizeof(struct acpi_evaluate_info));
+			info.evaluate_info->prefix_node = handle;
+			info.evaluate_info->relative_pathname =
+			    METHOD_NAME__INI;
+			info.evaluate_info->parameters = NULL;
+			info.evaluate_info->flags = ACPI_IGNORE_RETURN_VALUE;
+
+			status = acpi_ns_evaluate(info.evaluate_info);
+			if (ACPI_SUCCESS(status)) {
+				info.num_INI++;
+			}
+		}
 	}
 
 	/*
@@ -198,6 +220,12 @@ acpi_status acpi_ns_initialize_devices(u32 flags)
 	 * Note: Any objects accessed by the _REG methods will be automatically
 	 * initialized, even if they contain executable AML (see the call to
 	 * acpi_ns_initialize_objects below).
+	 *
+	 * Note: According to the ACPI specification, we actually needn't execute
+	 * _REG for system_memory/system_io operation regions, but for PCI_Config
+	 * operation regions, it is required to evaluate _REG for those on a PCI
+	 * root bus that doesn't contain _BBN object. So this code is kept here
+	 * in order not to break things.
 	 */
 	if (!(flags & ACPI_NO_ADDRESS_SPACE_INIT)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
@@ -592,32 +620,37 @@ acpi_ns_init_one_device(acpi_handle obj_handle,
 	 * Note: We know there is an _INI within this subtree, but it may not be
 	 * under this particular device, it may be lower in the branch.
 	 */
-	ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
-			(ACPI_TYPE_METHOD, device_node, METHOD_NAME__INI));
-
-	memset(info, 0, sizeof(struct acpi_evaluate_info));
-	info->prefix_node = device_node;
-	info->relative_pathname = METHOD_NAME__INI;
-	info->parameters = NULL;
-	info->flags = ACPI_IGNORE_RETURN_VALUE;
-
-	status = acpi_ns_evaluate(info);
-	if (ACPI_SUCCESS(status)) {
-		walk_info->num_INI++;
-	}
+	if (!ACPI_COMPARE_NAME(device_node->name.ascii, "_SB_") ||
+	    device_node->parent != acpi_gbl_root_node) {
+		ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
+				(ACPI_TYPE_METHOD, device_node,
+				 METHOD_NAME__INI));
+
+		memset(info, 0, sizeof(struct acpi_evaluate_info));
+		info->prefix_node = device_node;
+		info->relative_pathname = METHOD_NAME__INI;
+		info->parameters = NULL;
+		info->flags = ACPI_IGNORE_RETURN_VALUE;
+
+		status = acpi_ns_evaluate(info);
+		if (ACPI_SUCCESS(status)) {
+			walk_info->num_INI++;
+		}
 #ifdef ACPI_DEBUG_OUTPUT
-	else if (status != AE_NOT_FOUND) {
+		else if (status != AE_NOT_FOUND) {
 
-		/* Ignore error and move on to next device */
+			/* Ignore error and move on to next device */
 
-		char *scope_name =
-		    acpi_ns_get_normalized_pathname(device_node, TRUE);
+			char *scope_name =
+			    acpi_ns_get_normalized_pathname(device_node, TRUE);
 
-		ACPI_EXCEPTION((AE_INFO, status, "during %s._INI execution",
-				scope_name));
-		ACPI_FREE(scope_name);
-	}
+			ACPI_EXCEPTION((AE_INFO, status,
+					"during %s._INI execution",
+					scope_name));
+			ACPI_FREE(scope_name);
+		}
 #endif
+	}
 
 	/* Ignore errors from above */
 
-- 
1.7.10