Merge git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86

[linux-2.6-omap-h63xx.git] / drivers / acpi / tables / tbutils.c

diff --git a/drivers/acpi/tables/tbutils.c b/drivers/acpi/tables/tbutils.c
index 1da64b4518c0b390fab3a4a65625ca92b75cf32b..010f19652f80a633305a9da6c73729a73f58f545 100644 (file)
--- a/drivers/acpi/tables/tbutils.c
+++ b/drivers/acpi/tables/tbutils.c
@@ -51,6 +51,65 @@ ACPI_MODULE_NAME("tbutils")
 static acpi_physical_address
 acpi_tb_get_root_table_entry(u8 * table_entry,
                             acpi_native_uint table_entry_size);
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_check_xsdt
+ *
+ * PARAMETERS:  address                    - Pointer to the XSDT
+ *
+ * RETURN:      status
+ *             AE_OK - XSDT is okay
+ *             AE_NO_MEMORY - can't map XSDT
+ *             AE_INVALID_TABLE_LENGTH - invalid table length
+ *             AE_NULL_ENTRY - XSDT has NULL entry
+ *
+ * DESCRIPTION: validate XSDT
+******************************************************************************/
+
+static acpi_status
+acpi_tb_check_xsdt(acpi_physical_address address)
+{
+       struct acpi_table_header *table;
+       u32 length;
+       u64 xsdt_entry_address;
+       u8 *table_entry;
+       u32 table_count;
+       int i;
+
+       table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
+       if (!table)
+               return AE_NO_MEMORY;
+
+       length = table->length;
+       acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
+       if (length < sizeof(struct acpi_table_header))
+               return AE_INVALID_TABLE_LENGTH;
+
+       table = acpi_os_map_memory(address, length);
+       if (!table)
+               return AE_NO_MEMORY;
+
+       /* Calculate the number of tables described in XSDT */
+       table_count =
+               (u32) ((table->length -
+               sizeof(struct acpi_table_header)) / sizeof(u64));
+       table_entry =
+               ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
+       for (i = 0; i < table_count; i++) {
+               ACPI_MOVE_64_TO_64(&xsdt_entry_address, table_entry);
+               if (!xsdt_entry_address) {
+                       /* XSDT has NULL entry */
+                       break;
+               }
+               table_entry += sizeof(u64);
+       }
+       acpi_os_unmap_memory(table, length);
+
+       if (i < table_count)
+               return AE_NULL_ENTRY;
+       else
+               return AE_OK;
+}
 
 /*******************************************************************************
  *
@@ -341,6 +400,7 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address, u8 flags)
        u32 table_count;
        struct acpi_table_header *table;
        acpi_physical_address address;
+       acpi_physical_address uninitialized_var(rsdt_address);
        u32 length;
        u8 *table_entry;
        acpi_status status;
@@ -369,6 +429,8 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address, u8 flags)
                 */
                address = (acpi_physical_address) rsdp->xsdt_physical_address;
                table_entry_size = sizeof(u64);
+               rsdt_address = (acpi_physical_address)
+                                       rsdp->rsdt_physical_address;
        } else {
                /* Root table is an RSDT (32-bit physical addresses) */
 
@@ -382,6 +444,15 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address, u8 flags)
         */
        acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
 
+       if (table_entry_size == sizeof(u64)) {
+               if (acpi_tb_check_xsdt(address) == AE_NULL_ENTRY) {
+                       /* XSDT has NULL entry, RSDT is used */
+                       address = rsdt_address;
+                       table_entry_size = sizeof(u32);
+                       ACPI_WARNING((AE_INFO, "BIOS XSDT has NULL entry, "
+                                       "using RSDT"));
+               }
+       }
        /* Map the RSDT/XSDT table header to get the full table length */
 
        table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));