--- zzzz-none-000/linux-3.10.107/drivers/acpi/acpica/tbxfroot.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/acpi/acpica/tbxfroot.c	2021-02-04 17:41:59.000000000 +0000
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2013, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -48,10 +48,35 @@
 #define _COMPONENT          ACPI_TABLES
 ACPI_MODULE_NAME("tbxfroot")
 
-/* Local prototypes */
-static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length);
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_get_rsdp_length
+ *
+ * PARAMETERS:  rsdp                - Pointer to RSDP
+ *
+ * RETURN:      Table length
+ *
+ * DESCRIPTION: Get the length of the RSDP
+ *
+ ******************************************************************************/
+u32 acpi_tb_get_rsdp_length(struct acpi_table_rsdp *rsdp)
+{
 
-static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
+	if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature)) {
+
+		/* BAD Signature */
+
+		return (0);
+	}
+
+	/* "Length" field is available if table version >= 2 */
+
+	if (rsdp->revision >= 2) {
+		return (rsdp->length);
+	} else {
+		return (ACPI_RSDP_CHECKSUM_LENGTH);
+	}
+}
 
 /*******************************************************************************
  *
@@ -65,7 +90,7 @@
  *
  ******************************************************************************/
 
-static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
+acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp * rsdp)
 {
 
 	/*
@@ -74,8 +99,7 @@
 	 * Note: Sometimes there exists more than one RSDP in memory; the valid
 	 * RSDP has a valid checksum, all others have an invalid checksum.
 	 */
-	if (ACPI_STRNCMP((char *)rsdp, ACPI_SIG_RSDP,
-			 sizeof(ACPI_SIG_RSDP) - 1) != 0) {
+	if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature)) {
 
 		/* Nope, BAD Signature */
 
@@ -118,7 +142,7 @@
  *
  ******************************************************************************/
 
-acpi_status acpi_find_root_pointer(acpi_physical_address * table_address)
+acpi_status __init acpi_find_root_pointer(acpi_physical_address * table_address)
 {
 	u8 *table_ptr;
 	u8 *mem_rover;
@@ -232,7 +256,7 @@
  * DESCRIPTION: Search a block of memory for the RSDP signature
  *
  ******************************************************************************/
-static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length)
+u8 *acpi_tb_scan_memory_for_rsdp(u8 *start_address, u32 length)
 {
 	acpi_status status;
 	u8 *mem_rover;