1 files changed, 64 insertions, 3 deletions

diff --git a/drivers/acpi/tables/tbutils.c b/drivers/acpi/tables/tbutils.c
index e69d01d443d2..6fc1e36e6042 100644
--- a/drivers/acpi/tables/tbutils.c
+++ b/drivers/acpi/tables/tbutils.c
@@ -61,6 +61,67 @@ acpi_tb_handle_to_object (
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_tb_is_table_installed
+ *
+ * PARAMETERS:  new_table_desc      - Descriptor for new table being installed
+ *
+ * RETURN:      Status - AE_ALREADY_EXISTS if the table is already installed
+ *
+ * DESCRIPTION: Determine if an ACPI table is already installed
+ *
+ * MUTEX:       Table data structures should be locked
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_tb_is_table_installed (
+        struct acpi_table_desc          *new_table_desc)
+{
+        struct acpi_table_desc          *table_desc;
+
+
+        ACPI_FUNCTION_TRACE ("tb_is_table_installed");
+
+
+        /* Get the list descriptor and first table descriptor */
+
+        table_desc = acpi_gbl_table_lists[new_table_desc->type].next;
+
+        /* Examine all installed tables of this type */
+
+        while (table_desc) {
+                /* Compare Revision and oem_table_id */
+
+                if ((table_desc->loaded_into_namespace) &&
+                        (table_desc->pointer->revision ==
+                                        new_table_desc->pointer->revision) &&
+                        (!ACPI_MEMCMP (table_desc->pointer->oem_table_id,
+                                        new_table_desc->pointer->oem_table_id, 8))) {
+                        /* This table is already installed */
+
+                        ACPI_DEBUG_PRINT ((ACPI_DB_TABLES,
+                                "Table [%4.4s] already installed: Rev %X oem_table_id [%8.8s]\n",
+                                new_table_desc->pointer->signature,
+                                new_table_desc->pointer->revision,
+                                new_table_desc->pointer->oem_table_id));
+
+                        new_table_desc->owner_id    = table_desc->owner_id;
+                        new_table_desc->installed_desc = table_desc;
+
+                        return_ACPI_STATUS (AE_ALREADY_EXISTS);
+                }
+
+                /* Get next table on the list */
+
+                table_desc = table_desc->next;
+        }
+
+        return_ACPI_STATUS (AE_OK);
+}
+
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_tb_validate_table_header
  *
  * PARAMETERS:  table_header        - Logical pointer to the table
@@ -157,7 +218,7 @@ acpi_tb_verify_table_checksum (
 
         /* Compute the checksum on the table */
 
-        checksum = acpi_tb_checksum (table_header, table_header->length);
+        checksum = acpi_tb_generate_checksum (table_header, table_header->length);
 
         /* Return the appropriate exception */
 
@@ -175,7 +236,7 @@ acpi_tb_verify_table_checksum (
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_tb_checksum
+ * FUNCTION:    acpi_tb_generate_checksum
  *
  * PARAMETERS:  Buffer              - Buffer to checksum
  *              Length              - Size of the buffer
@@ -187,7 +248,7 @@ acpi_tb_verify_table_checksum (
  ******************************************************************************/
 
 u8
-acpi_tb_checksum (
+acpi_tb_generate_checksum (
         void                            *buffer,
         u32                             length)
 {