Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[linux-drm-fsl-dcu.git] / drivers / acpi / tables / tbxface.c
index 7767987be15a0d517acf10fa5b6327b203e08f23..807978d5381abb34767687de505600b0e8d6aa8a 100644 (file)
@@ -6,7 +6,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2006, R. Byron Moore
+ * Copyright (C) 2000 - 2007, R. Byron Moore
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
 #define _COMPONENT          ACPI_TABLES
 ACPI_MODULE_NAME("tbxface")
 
+/* Local prototypes */
+static acpi_status acpi_tb_load_namespace(void);
+
 /*******************************************************************************
  *
- * FUNCTION:    acpi_load_tables
+ * FUNCTION:    acpi_allocate_root_table
  *
- * PARAMETERS:  None
+ * PARAMETERS:  initial_table_count - Size of initial_table_array, in number of
+ *                                    struct acpi_table_desc structures
  *
  * RETURN:      Status
  *
- * DESCRIPTION: This function is called to load the ACPI tables from the
- *              provided RSDT
+ * DESCRIPTION: Allocate a root table array. Used by i_aSL compiler and
+ *              acpi_initialize_tables.
  *
  ******************************************************************************/
-acpi_status acpi_load_tables(void)
+
+acpi_status acpi_allocate_root_table(u32 initial_table_count)
 {
-       struct acpi_pointer rsdp_address;
-       acpi_status status;
 
-       ACPI_FUNCTION_TRACE(acpi_load_tables);
+       acpi_gbl_root_table_list.size = initial_table_count;
+       acpi_gbl_root_table_list.flags = ACPI_ROOT_ALLOW_RESIZE;
 
-       /* Get the RSDP */
+       return (acpi_tb_resize_root_table_list());
+}
 
-       status = acpi_os_get_root_pointer(ACPI_LOGICAL_ADDRESSING,
-                                         &rsdp_address);
-       if (ACPI_FAILURE(status)) {
-               ACPI_EXCEPTION((AE_INFO, status, "Could not get the RSDP"));
-               goto error_exit;
-       }
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_initialize_tables
+ *
+ * PARAMETERS:  initial_table_array - Pointer to an array of pre-allocated
+ *                                    struct acpi_table_desc structures. If NULL, the
+ *                                    array is dynamically allocated.
+ *              initial_table_count - Size of initial_table_array, in number of
+ *                                    struct acpi_table_desc structures
+ *              allow_realloc       - Flag to tell Table Manager if resize of
+ *                                    pre-allocated array is allowed. Ignored
+ *                                    if initial_table_array is NULL.
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Initialize the table manager, get the RSDP and RSDT/XSDT.
+ *
+ * NOTE:        Allows static allocation of the initial table array in order
+ *              to avoid the use of dynamic memory in confined environments
+ *              such as the kernel boot sequence where it may not be available.
+ *
+ *              If the host OS memory managers are initialized, use NULL for
+ *              initial_table_array, and the table will be dynamically allocated.
+ *
+ ******************************************************************************/
 
-       /* Map and validate the RSDP */
+acpi_status __init
+acpi_initialize_tables(struct acpi_table_desc * initial_table_array,
+                      u32 initial_table_count, u8 allow_resize)
+{
+       acpi_physical_address rsdp_address;
+       acpi_status status;
 
-       acpi_gbl_table_flags = rsdp_address.pointer_type;
+       ACPI_FUNCTION_TRACE(acpi_initialize_tables);
 
-       status = acpi_tb_verify_rsdp(&rsdp_address);
-       if (ACPI_FAILURE(status)) {
-               ACPI_EXCEPTION((AE_INFO, status, "During RSDP validation"));
-               goto error_exit;
+       /*
+        * Set up the Root Table Array
+        * Allocate the table array if requested
+        */
+       if (!initial_table_array) {
+               status = acpi_allocate_root_table(initial_table_count);
+               if (ACPI_FAILURE(status)) {
+                       return_ACPI_STATUS(status);
+               }
+       } else {
+               /* Root Table Array has been statically allocated by the host */
+
+               ACPI_MEMSET(initial_table_array, 0,
+                           initial_table_count *
+                           sizeof(struct acpi_table_desc));
+
+               acpi_gbl_root_table_list.tables = initial_table_array;
+               acpi_gbl_root_table_list.size = initial_table_count;
+               acpi_gbl_root_table_list.flags = ACPI_ROOT_ORIGIN_UNKNOWN;
+               if (allow_resize) {
+                       acpi_gbl_root_table_list.flags |=
+                           ACPI_ROOT_ALLOW_RESIZE;
+               }
        }
 
-       /* Get the RSDT via the RSDP */
+       /* Get the address of the RSDP */
 
-       status = acpi_tb_get_table_rsdt();
-       if (ACPI_FAILURE(status)) {
-               ACPI_EXCEPTION((AE_INFO, status, "Could not load RSDT"));
-               goto error_exit;
+       rsdp_address = acpi_os_get_root_pointer();
+       if (!rsdp_address) {
+               return_ACPI_STATUS(AE_NOT_FOUND);
        }
 
-       /* Now get the tables needed by this subsystem (FADT, DSDT, etc.) */
+       /*
+        * Get the root table (RSDT or XSDT) and extract all entries to the local
+        * Root Table Array. This array contains the information of the RSDT/XSDT
+        * in a common, more useable format.
+        */
+       status =
+           acpi_tb_parse_root_table(rsdp_address, ACPI_TABLE_ORIGIN_MAPPED);
+       return_ACPI_STATUS(status);
+}
 
-       status = acpi_tb_get_required_tables();
-       if (ACPI_FAILURE(status)) {
-               ACPI_EXCEPTION((AE_INFO, status,
-                               "Could not get all required tables (DSDT/FADT/FACS)"));
-               goto error_exit;
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_reallocate_root_table
+ *
+ * PARAMETERS:  None
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Reallocate Root Table List into dynamic memory. Copies the
+ *              root list from the previously provided scratch area. Should
+ *              be called once dynamic memory allocation is available in the
+ *              kernel
+ *
+ ******************************************************************************/
+acpi_status acpi_reallocate_root_table(void)
+{
+       struct acpi_table_desc *tables;
+       acpi_size new_size;
+
+       ACPI_FUNCTION_TRACE(acpi_reallocate_root_table);
+
+       /*
+        * Only reallocate the root table if the host provided a static buffer
+        * for the table array in the call to acpi_initialize_tables.
+        */
+       if (acpi_gbl_root_table_list.flags & ACPI_ROOT_ORIGIN_ALLOCATED) {
+               return_ACPI_STATUS(AE_SUPPORT);
        }
 
-       ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));
+       new_size =
+           (acpi_gbl_root_table_list.count +
+            ACPI_ROOT_TABLE_SIZE_INCREMENT) * sizeof(struct acpi_table_desc);
 
-       /* Load the namespace from the tables */
+       /* Create new array and copy the old array */
 
-       status = acpi_ns_load_namespace();
-       if (ACPI_FAILURE(status)) {
-               ACPI_EXCEPTION((AE_INFO, status, "Could not load namespace"));
-               goto error_exit;
+       tables = ACPI_ALLOCATE_ZEROED(new_size);
+       if (!tables) {
+               return_ACPI_STATUS(AE_NO_MEMORY);
        }
 
-       return_ACPI_STATUS(AE_OK);
+       ACPI_MEMCPY(tables, acpi_gbl_root_table_list.tables, new_size);
 
-      error_exit:
-       ACPI_EXCEPTION((AE_INFO, status, "Could not load tables"));
-       return_ACPI_STATUS(status);
-}
+       acpi_gbl_root_table_list.size = acpi_gbl_root_table_list.count;
+       acpi_gbl_root_table_list.tables = tables;
+       acpi_gbl_root_table_list.flags =
+           ACPI_ROOT_ORIGIN_ALLOCATED | ACPI_ROOT_ALLOW_RESIZE;
 
-ACPI_EXPORT_SYMBOL(acpi_load_tables)
-
-#ifdef ACPI_FUTURE_USAGE
+       return_ACPI_STATUS(AE_OK);
+}
 /*******************************************************************************
  *
  * FUNCTION:    acpi_load_table
@@ -142,289 +219,405 @@ ACPI_EXPORT_SYMBOL(acpi_load_tables)
 acpi_status acpi_load_table(struct acpi_table_header *table_ptr)
 {
        acpi_status status;
-       struct acpi_table_desc table_info;
-       struct acpi_pointer address;
+       acpi_native_uint table_index;
+       struct acpi_table_desc table_desc;
 
-       ACPI_FUNCTION_TRACE(acpi_load_table);
+       if (!table_ptr)
+               return AE_BAD_PARAMETER;
 
-       if (!table_ptr) {
-               return_ACPI_STATUS(AE_BAD_PARAMETER);
-       }
-
-       /* Copy the table to a local buffer */
+       ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
+       table_desc.pointer = table_ptr;
+       table_desc.length = table_ptr->length;
+       table_desc.flags = ACPI_TABLE_ORIGIN_UNKNOWN;
 
-       address.pointer_type = ACPI_LOGICAL_POINTER | ACPI_LOGICAL_ADDRESSING;
-       address.pointer.logical = table_ptr;
-
-       status = acpi_tb_get_table_body(&address, table_ptr, &table_info);
+       /*
+        * Install the new table into the local data structures
+        */
+       status = acpi_tb_add_table(&table_desc, &table_index);
        if (ACPI_FAILURE(status)) {
-               return_ACPI_STATUS(status);
+               return status;
        }
+       status = acpi_ns_load_table(table_index, acpi_gbl_root_node);
+       return status;
+}
 
-       /* Check signature for a valid table type */
-
-       status = acpi_tb_recognize_table(&table_info, ACPI_TABLE_ALL);
-       if (ACPI_FAILURE(status)) {
-               return_ACPI_STATUS(status);
-       }
+ACPI_EXPORT_SYMBOL(acpi_load_table)
 
-       /* Install the new table into the local data structures */
+/******************************************************************************
+ *
+ * FUNCTION:    acpi_get_table_header
+ *
+ * PARAMETERS:  Signature           - ACPI signature of needed table
+ *              Instance            - Which instance (for SSDTs)
+ *              out_table_header    - The pointer to the table header to fill
+ *
+ * RETURN:      Status and pointer to mapped table header
+ *
+ * DESCRIPTION: Finds an ACPI table header.
+ *
+ * NOTE:        Caller is responsible in unmapping the header with
+ *              acpi_os_unmap_memory
+ *
+ *****************************************************************************/
+acpi_status
+acpi_get_table_header(char *signature,
+                     acpi_native_uint instance,
+                     struct acpi_table_header *out_table_header)
+{
+       acpi_native_uint i;
+       acpi_native_uint j;
+       struct acpi_table_header *header;
 
-       status = acpi_tb_install_table(&table_info);
-       if (ACPI_FAILURE(status)) {
-               if (status == AE_ALREADY_EXISTS) {
+       /* Parameter validation */
 
-                       /* Table already exists, no error */
+       if (!signature || !out_table_header) {
+               return (AE_BAD_PARAMETER);
+       }
 
-                       status = AE_OK;
+       /*
+        * Walk the root table list
+        */
+       for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
+               if (!ACPI_COMPARE_NAME
+                   (&(acpi_gbl_root_table_list.tables[i].signature),
+                    signature)) {
+                       continue;
                }
 
-               /* Free table allocated by acpi_tb_get_table_body */
+               if (++j < instance) {
+                       continue;
+               }
 
-               acpi_tb_delete_single_table(&table_info);
-               return_ACPI_STATUS(status);
+               if (!acpi_gbl_root_table_list.tables[i].pointer) {
+                       if ((acpi_gbl_root_table_list.tables[i].
+                            flags & ACPI_TABLE_ORIGIN_MASK) ==
+                           ACPI_TABLE_ORIGIN_MAPPED) {
+                               header =
+                                   acpi_os_map_memory(acpi_gbl_root_table_list.
+                                                      tables[i].address,
+                                                      sizeof(struct
+                                                             acpi_table_header));
+                               if (!header) {
+                                       return AE_NO_MEMORY;
+                               }
+                               ACPI_MEMCPY(out_table_header, header,
+                                           sizeof(struct acpi_table_header));
+                               acpi_os_unmap_memory(header,
+                                                    sizeof(struct
+                                                           acpi_table_header));
+                       } else {
+                               return AE_NOT_FOUND;
+                       }
+               } else {
+                       ACPI_MEMCPY(out_table_header,
+                                   acpi_gbl_root_table_list.tables[i].pointer,
+                                   sizeof(struct acpi_table_header));
+               }
+               return (AE_OK);
        }
 
-       /* Convert the table to common format if necessary */
-
-       switch (table_info.type) {
-       case ACPI_TABLE_ID_FADT:
-
-               status = acpi_tb_convert_table_fadt();
-               break;
-
-       case ACPI_TABLE_ID_FACS:
-
-               status = acpi_tb_build_common_facs(&table_info);
-               break;
+       return (AE_NOT_FOUND);
+}
 
-       default:
-               /* Load table into namespace if it contains executable AML */
+ACPI_EXPORT_SYMBOL(acpi_get_table_header)
 
-               status =
-                   acpi_ns_load_table(table_info.installed_desc,
-                                      acpi_gbl_root_node);
-               break;
-       }
 
-       if (ACPI_FAILURE(status)) {
+/******************************************************************************
+ *
+ * FUNCTION:    acpi_unload_table_id
+ *
+ * PARAMETERS:  id            - Owner ID of the table to be removed.
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: This routine is used to force the unload of a table (by id)
+ *
+ ******************************************************************************/
+acpi_status acpi_unload_table_id(acpi_owner_id id)
+{
+       int i;
+       acpi_status status = AE_NOT_EXIST;
 
-               /* Uninstall table and free the buffer */
+       ACPI_FUNCTION_TRACE(acpi_unload_table);
 
-               (void)acpi_tb_uninstall_table(table_info.installed_desc);
+       /* Find table from the requested type list */
+       for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
+               if (id != acpi_gbl_root_table_list.tables[i].owner_id) {
+                       continue;
+               }
+               /*
+               * Delete all namespace objects owned by this table. Note that these
+               * objects can appear anywhere in the namespace by virtue of the AML
+               * "Scope" operator. Thus, we need to track ownership by an ID, not
+               * simply a position within the hierarchy
+               */
+               acpi_tb_delete_namespace_by_owner(i);
+               acpi_tb_release_owner_id(i);
+               acpi_tb_set_table_loaded_flag(i, FALSE);
        }
-
        return_ACPI_STATUS(status);
 }
 
-ACPI_EXPORT_SYMBOL(acpi_load_table)
+ACPI_EXPORT_SYMBOL(acpi_unload_table_id)
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_unload_table
+ * FUNCTION:    acpi_get_table
  *
- * PARAMETERS:  table_type    - Type of table to be unloaded
+ * PARAMETERS:  Signature           - ACPI signature of needed table
+ *              Instance            - Which instance (for SSDTs)
+ *              out_table           - Where the pointer to the table is returned
  *
- * RETURN:      Status
+ * RETURN:      Status and pointer to table
  *
- * DESCRIPTION: This routine is used to force the unload of a table
+ * DESCRIPTION: Finds and verifies an ACPI table.
  *
- ******************************************************************************/
-acpi_status acpi_unload_table(acpi_table_type table_type)
+ *****************************************************************************/
+acpi_status
+acpi_get_table(char *signature,
+              acpi_native_uint instance, struct acpi_table_header ** out_table)
 {
-       struct acpi_table_desc *table_desc;
-
-       ACPI_FUNCTION_TRACE(acpi_unload_table);
+       acpi_native_uint i;
+       acpi_native_uint j;
+       acpi_status status;
 
        /* Parameter validation */
 
-       if (table_type > ACPI_TABLE_ID_MAX) {
-               return_ACPI_STATUS(AE_BAD_PARAMETER);
+       if (!signature || !out_table) {
+               return (AE_BAD_PARAMETER);
        }
 
-       /* Find all tables of the requested type */
+       /*
+        * Walk the root table list
+        */
+       for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
+               if (!ACPI_COMPARE_NAME
+                   (&(acpi_gbl_root_table_list.tables[i].signature),
+                    signature)) {
+                       continue;
+               }
 
-       table_desc = acpi_gbl_table_lists[table_type].next;
-       if (!table_desc) {
-               return_ACPI_STATUS(AE_NOT_EXIST);
-       }
+               if (++j < instance) {
+                       continue;
+               }
 
-       while (table_desc) {
-               /*
-                * Delete all namespace objects owned by this table. Note that these
-                * objects can appear anywhere in the namespace by virtue of the AML
-                * "Scope" operator. Thus, we need to track ownership by an ID, not
-                * simply a position within the hierarchy
-                */
-               acpi_ns_delete_namespace_by_owner(table_desc->owner_id);
-               table_desc = table_desc->next;
-       }
+               status =
+                   acpi_tb_verify_table(&acpi_gbl_root_table_list.tables[i]);
+               if (ACPI_SUCCESS(status)) {
+                       *out_table = acpi_gbl_root_table_list.tables[i].pointer;
+               }
 
-       /* Delete (or unmap) all tables of this type */
+               if (!acpi_gbl_permanent_mmap) {
+                       acpi_gbl_root_table_list.tables[i].pointer = 0;
+               }
 
-       acpi_tb_delete_tables_by_type(table_type);
-       return_ACPI_STATUS(AE_OK);
+               return (status);
+       }
+
+       return (AE_NOT_FOUND);
 }
 
-ACPI_EXPORT_SYMBOL(acpi_unload_table)
+ACPI_EXPORT_SYMBOL(acpi_get_table)
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_get_table_header
+ * FUNCTION:    acpi_get_table_by_index
  *
- * PARAMETERS:  table_type      - one of the defined table types
- *              Instance        - the non zero instance of the table, allows
- *                                support for multiple tables of the same type
- *                                see acpi_gbl_acpi_table_flag
- *              out_table_header - pointer to the struct acpi_table_header if successful
+ * PARAMETERS:  table_index         - Table index
+ *              Table               - Where the pointer to the table is returned
  *
- * DESCRIPTION: This function is called to get an ACPI table header. The caller
- *              supplies an pointer to a data area sufficient to contain an ACPI
- *              struct acpi_table_header structure.
+ * RETURN:      Status and pointer to the table
  *
- *              The header contains a length field that can be used to determine
- *              the size of the buffer needed to contain the entire table. This
- *              function is not valid for the RSD PTR table since it does not
- *              have a standard header and is fixed length.
+ * DESCRIPTION: Obtain a table by an index into the global table list.
  *
  ******************************************************************************/
 acpi_status
-acpi_get_table_header(acpi_table_type table_type,
-                     u32 instance, struct acpi_table_header *out_table_header)
+acpi_get_table_by_index(acpi_native_uint table_index,
+                       struct acpi_table_header ** table)
 {
-       struct acpi_table_header *tbl_ptr;
        acpi_status status;
 
-       ACPI_FUNCTION_TRACE(acpi_get_table_header);
+       ACPI_FUNCTION_TRACE(acpi_get_table_by_index);
+
+       /* Parameter validation */
 
-       if ((instance == 0) ||
-           (table_type == ACPI_TABLE_ID_RSDP) || (!out_table_header)) {
+       if (!table) {
                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }
 
-       /* Check the table type and instance */
+       (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 
-       if ((table_type > ACPI_TABLE_ID_MAX) ||
-           (ACPI_IS_SINGLE_TABLE(acpi_gbl_table_data[table_type].flags) &&
-            instance > 1)) {
+       /* Validate index */
+
+       if (table_index >= acpi_gbl_root_table_list.count) {
+               (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }
 
-       /* Get a pointer to the entire table */
-
-       status = acpi_tb_get_table_ptr(table_type, instance, &tbl_ptr);
-       if (ACPI_FAILURE(status)) {
-               return_ACPI_STATUS(status);
-       }
+       if (!acpi_gbl_root_table_list.tables[table_index].pointer) {
 
-       /* The function will return a NULL pointer if the table is not loaded */
+               /* Table is not mapped, map it */
 
-       if (tbl_ptr == NULL) {
-               return_ACPI_STATUS(AE_NOT_EXIST);
+               status =
+                   acpi_tb_verify_table(&acpi_gbl_root_table_list.
+                                        tables[table_index]);
+               if (ACPI_FAILURE(status)) {
+                       (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
+                       return_ACPI_STATUS(status);
+               }
        }
 
-       /* Copy the header to the caller's buffer */
-
-       ACPI_MEMCPY(ACPI_CAST_PTR(void, out_table_header),
-                   ACPI_CAST_PTR(void, tbl_ptr),
-                   sizeof(struct acpi_table_header));
-
-       return_ACPI_STATUS(status);
+       *table = acpi_gbl_root_table_list.tables[table_index].pointer;
+       (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
+       return_ACPI_STATUS(AE_OK);
 }
 
-ACPI_EXPORT_SYMBOL(acpi_get_table_header)
-#endif                         /*  ACPI_FUTURE_USAGE  */
+ACPI_EXPORT_SYMBOL(acpi_get_table_by_index)
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_get_table
+ * FUNCTION:    acpi_tb_load_namespace
  *
- * PARAMETERS:  table_type      - one of the defined table types
- *              Instance        - the non zero instance of the table, allows
- *                                support for multiple tables of the same type
- *                                see acpi_gbl_acpi_table_flag
- *              ret_buffer      - pointer to a structure containing a buffer to
- *                                receive the table
+ * PARAMETERS:  None
  *
  * RETURN:      Status
  *
- * DESCRIPTION: This function is called to get an ACPI table. The caller
- *              supplies an out_buffer large enough to contain the entire ACPI
- *              table. The caller should call the acpi_get_table_header function
- *              first to determine the buffer size needed. Upon completion
- *              the out_buffer->Length field will indicate the number of bytes
- *              copied into the out_buffer->buf_ptr buffer. This table will be
- *              a complete table including the header.
+ * DESCRIPTION: Load the namespace from the DSDT and all SSDTs/PSDTs found in
+ *              the RSDT/XSDT.
  *
  ******************************************************************************/
-acpi_status
-acpi_get_table(acpi_table_type table_type,
-              u32 instance, struct acpi_buffer *ret_buffer)
+static acpi_status acpi_tb_load_namespace(void)
 {
-       struct acpi_table_header *tbl_ptr;
        acpi_status status;
-       acpi_size table_length;
+       struct acpi_table_header *table;
+       acpi_native_uint i;
 
-       ACPI_FUNCTION_TRACE(acpi_get_table);
+       ACPI_FUNCTION_TRACE(tb_load_namespace);
 
-       /* Parameter validation */
+       (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 
-       if (instance == 0) {
-               return_ACPI_STATUS(AE_BAD_PARAMETER);
+       /*
+        * Load the namespace. The DSDT is required, but any SSDT and PSDT tables
+        * are optional.
+        */
+       if (!acpi_gbl_root_table_list.count ||
+           !ACPI_COMPARE_NAME(&
+                              (acpi_gbl_root_table_list.
+                               tables[ACPI_TABLE_INDEX_DSDT].signature),
+                              ACPI_SIG_DSDT)
+           ||
+           ACPI_FAILURE(acpi_tb_verify_table
+                        (&acpi_gbl_root_table_list.
+                         tables[ACPI_TABLE_INDEX_DSDT]))) {
+               status = AE_NO_ACPI_TABLES;
+               goto unlock_and_exit;
        }
 
-       status = acpi_ut_validate_buffer(ret_buffer);
-       if (ACPI_FAILURE(status)) {
-               return_ACPI_STATUS(status);
+       /*
+        * Find DSDT table
+        */
+       status =
+           acpi_os_table_override(acpi_gbl_root_table_list.
+                                  tables[ACPI_TABLE_INDEX_DSDT].pointer,
+                                  &table);
+       if (ACPI_SUCCESS(status) && table) {
+               /*
+                * DSDT table has been found
+                */
+               acpi_tb_delete_table(&acpi_gbl_root_table_list.
+                                    tables[ACPI_TABLE_INDEX_DSDT]);
+               acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].pointer =
+                   table;
+               acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].length =
+                   table->length;
+               acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].flags =
+                   ACPI_TABLE_ORIGIN_UNKNOWN;
+
+               ACPI_INFO((AE_INFO, "Table DSDT replaced by host OS"));
+               acpi_tb_print_table_header(0, table);
        }
 
-       /* Check the table type and instance */
+       status =
+           acpi_tb_verify_table(&acpi_gbl_root_table_list.
+                                tables[ACPI_TABLE_INDEX_DSDT]);
+       if (ACPI_FAILURE(status)) {
 
-       if ((table_type > ACPI_TABLE_ID_MAX) ||
-           (ACPI_IS_SINGLE_TABLE(acpi_gbl_table_data[table_type].flags) &&
-            instance > 1)) {
-               return_ACPI_STATUS(AE_BAD_PARAMETER);
+               /* A valid DSDT is required */
+
+               status = AE_NO_ACPI_TABLES;
+               goto unlock_and_exit;
        }
 
-       /* Get a pointer to the entire table */
+       (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 
-       status = acpi_tb_get_table_ptr(table_type, instance, &tbl_ptr);
+       /*
+        * Load and parse tables.
+        */
+       status = acpi_ns_load_table(ACPI_TABLE_INDEX_DSDT, acpi_gbl_root_node);
        if (ACPI_FAILURE(status)) {
                return_ACPI_STATUS(status);
        }
 
        /*
-        * acpi_tb_get_table_ptr will return a NULL pointer if the
-        * table is not loaded.
+        * Load any SSDT or PSDT tables. Note: Loop leaves tables locked
         */
-       if (tbl_ptr == NULL) {
-               return_ACPI_STATUS(AE_NOT_EXIST);
+       (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
+       for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
+               if ((!ACPI_COMPARE_NAME
+                    (&(acpi_gbl_root_table_list.tables[i].signature),
+                     ACPI_SIG_SSDT)
+                    &&
+                    !ACPI_COMPARE_NAME(&
+                                       (acpi_gbl_root_table_list.tables[i].
+                                        signature), ACPI_SIG_PSDT))
+                   ||
+                   ACPI_FAILURE(acpi_tb_verify_table
+                                (&acpi_gbl_root_table_list.tables[i]))) {
+                       continue;
+               }
+
+               /* Ignore errors while loading tables, get as many as possible */
+
+               (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
+               (void)acpi_ns_load_table(i, acpi_gbl_root_node);
+               (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
        }
 
-       /* Get the table length */
+       ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));
 
-       if (table_type == ACPI_TABLE_ID_RSDP) {
+      unlock_and_exit:
+       (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
+       return_ACPI_STATUS(status);
+}
 
-               /* RSD PTR is the only "table" without a header */
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_load_tables
+ *
+ * PARAMETERS:  None
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Load the ACPI tables from the RSDT/XSDT
+ *
+ ******************************************************************************/
 
-               table_length = sizeof(struct rsdp_descriptor);
-       } else {
-               table_length = (acpi_size) tbl_ptr->length;
-       }
+acpi_status acpi_load_tables(void)
+{
+       acpi_status status;
 
-       /* Validate/Allocate/Clear caller buffer */
+       ACPI_FUNCTION_TRACE(acpi_load_tables);
 
-       status = acpi_ut_initialize_buffer(ret_buffer, table_length);
+       /*
+        * Load the namespace from the tables
+        */
+       status = acpi_tb_load_namespace();
        if (ACPI_FAILURE(status)) {
-               return_ACPI_STATUS(status);
+               ACPI_EXCEPTION((AE_INFO, status,
+                               "While loading namespace from ACPI tables"));
        }
 
-       /* Copy the table to the buffer */
-
-       ACPI_MEMCPY(ACPI_CAST_PTR(void, ret_buffer->pointer),
-                   ACPI_CAST_PTR(void, tbl_ptr), table_length);
-
-       return_ACPI_STATUS(AE_OK);
+       return_ACPI_STATUS(status);
 }
 
-ACPI_EXPORT_SYMBOL(acpi_get_table)
+ACPI_EXPORT_SYMBOL(acpi_load_tables)