3 files changed, 35 insertions, 2 deletions

diff --git a/drivers/acpi/acpica/actables.h b/drivers/acpi/acpica/actables.h
index f14882788eee..1afe46e44dac 100644
--- a/drivers/acpi/acpica/actables.h
+++ b/drivers/acpi/acpica/actables.h
@@ -49,6 +49,8 @@ acpi_status acpi_allocate_root_table(u32 initial_table_count);
 /*
  * tbxfroot - Root pointer utilities
  */
+u32 acpi_tb_get_rsdp_length(struct acpi_table_rsdp *rsdp);
+
 acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
 
 u8 *acpi_tb_scan_memory_for_rsdp(u8 *start_address, u32 length);
diff --git a/drivers/acpi/acpica/tbxfroot.c b/drivers/acpi/acpica/tbxfroot.c
index 65ab8fed3d5e..43a54af2b548 100644
--- a/drivers/acpi/acpica/tbxfroot.c
+++ b/drivers/acpi/acpica/tbxfroot.c
@@ -50,6 +50,36 @@ ACPI_MODULE_NAME("tbxfroot")
 
 /*******************************************************************************
  *
+ * 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)
+{
+
+        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);
+        }
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_tb_validate_rsdp
  *
  * PARAMETERS:  rsdp                - Pointer to unvalidated RSDP
@@ -59,7 +89,8 @@ ACPI_MODULE_NAME("tbxfroot")
  * DESCRIPTION: Validate the RSDP (ptr)
  *
  ******************************************************************************/
-acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
+
+acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp * rsdp)
 {
 
         /*
diff --git a/tools/power/acpi/tools/acpidump/apdump.c b/tools/power/acpi/tools/acpidump/apdump.c
index 53cee781e24e..24d32968802d 100644
--- a/tools/power/acpi/tools/acpidump/apdump.c
+++ b/tools/power/acpi/tools/acpidump/apdump.c
@@ -146,7 +146,7 @@ u32 ap_get_table_length(struct acpi_table_header *table)
 
         if (ACPI_VALIDATE_RSDP_SIG(table->signature)) {
                 rsdp = ACPI_CAST_PTR(struct acpi_table_rsdp, table);
-                return (rsdp->length);
+                return (acpi_tb_get_rsdp_length(rsdp));
         }
 
         /* Normal ACPI table */