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  1. /******************************************************************************
  2.  *
  3.  * Module Name: nsxfname - Public interfaces to the ACPI subsystem
  4.  *                         ACPI Namespace oriented interfaces
  5.  *
  6.  *****************************************************************************/
  7.  
  8. /*
  9.  * Copyright (C) 2000 - 2015, Intel Corp.
  10.  * All rights reserved.
  11.  *
  12.  * Redistribution and use in source and binary forms, with or without
  13.  * modification, are permitted provided that the following conditions
  14.  * are met:
  15.  * 1. Redistributions of source code must retain the above copyright
  16.  *    notice, this list of conditions, and the following disclaimer,
  17.  *    without modification.
  18.  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19.  *    substantially similar to the "NO WARRANTY" disclaimer below
  20.  *    ("Disclaimer") and any redistribution must be conditioned upon
  21.  *    including a substantially similar Disclaimer requirement for further
  22.  *    binary redistribution.
  23.  * 3. Neither the names of the above-listed copyright holders nor the names
  24.  *    of any contributors may be used to endorse or promote products derived
  25.  *    from this software without specific prior written permission.
  26.  *
  27.  * Alternatively, this software may be distributed under the terms of the
  28.  * GNU General Public License ("GPL") version 2 as published by the Free
  29.  * Software Foundation.
  30.  *
  31.  * NO WARRANTY
  32.  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33.  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34.  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35.  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36.  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37.  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38.  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39.  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40.  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41.  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42.  * POSSIBILITY OF SUCH DAMAGES.
  43.  */
  44.  
  45. #define EXPORT_ACPI_INTERFACES
  46.  
  47. #include <acpi/acpi.h>
  48. #include "accommon.h"
  49. #include "acnamesp.h"
  50. #include "acparser.h"
  51. #include "amlcode.h"
  52.  
  53. #define _COMPONENT          ACPI_NAMESPACE
  54. ACPI_MODULE_NAME("nsxfname")
  55.  
  56. /* Local prototypes */
  57. static char *acpi_ns_copy_device_id(struct acpi_pnp_device_id *dest,
  58.                                     struct acpi_pnp_device_id *source,
  59.                                     char *string_area);
  60.  
  61. /******************************************************************************
  62.  *
  63.  * FUNCTION:    acpi_get_handle
  64.  *
  65.  * PARAMETERS:  parent          - Object to search under (search scope).
  66.  *              pathname        - Pointer to an asciiz string containing the
  67.  *                                name
  68.  *              ret_handle      - Where the return handle is returned
  69.  *
  70.  * RETURN:      Status
  71.  *
  72.  * DESCRIPTION: This routine will search for a caller specified name in the
  73.  *              name space. The caller can restrict the search region by
  74.  *              specifying a non NULL parent. The parent value is itself a
  75.  *              namespace handle.
  76.  *
  77.  ******************************************************************************/
  78.  
  79. acpi_status
  80. acpi_get_handle(acpi_handle parent,
  81.                 acpi_string pathname, acpi_handle * ret_handle)
  82. {
  83.         acpi_status status;
  84.         struct acpi_namespace_node *node = NULL;
  85.         struct acpi_namespace_node *prefix_node = NULL;
  86.  
  87.         ACPI_FUNCTION_ENTRY();
  88.  
  89.         /* Parameter Validation */
  90.  
  91.         if (!ret_handle || !pathname) {
  92.                 return (AE_BAD_PARAMETER);
  93.         }
  94.  
  95.         /* Convert a parent handle to a prefix node */
  96.  
  97.         if (parent) {
  98.                 prefix_node = acpi_ns_validate_handle(parent);
  99.                 if (!prefix_node) {
  100.                         return (AE_BAD_PARAMETER);
  101.                 }
  102.         }
  103.  
  104.         /*
  105.          * Valid cases are:
  106.          * 1) Fully qualified pathname
  107.          * 2) Parent + Relative pathname
  108.          *
  109.          * Error for <null Parent + relative path>
  110.          */
  111.         if (ACPI_IS_ROOT_PREFIX(pathname[0])) {
  112.  
  113.                 /* Pathname is fully qualified (starts with '\') */
  114.  
  115.                 /* Special case for root-only, since we can't search for it */
  116.  
  117.                 if (!strcmp(pathname, ACPI_NS_ROOT_PATH)) {
  118.                         *ret_handle =
  119.                             ACPI_CAST_PTR(acpi_handle, acpi_gbl_root_node);
  120.                         return (AE_OK);
  121.                 }
  122.         } else if (!prefix_node) {
  123.  
  124.                 /* Relative path with null prefix is disallowed */
  125.  
  126.                 return (AE_BAD_PARAMETER);
  127.         }
  128.  
  129.         /* Find the Node and convert to a handle */
  130.  
  131.         status =
  132.             acpi_ns_get_node(prefix_node, pathname, ACPI_NS_NO_UPSEARCH, &node);
  133.         if (ACPI_SUCCESS(status)) {
  134.                 *ret_handle = ACPI_CAST_PTR(acpi_handle, node);
  135.         }
  136.  
  137.         return (status);
  138. }
  139.  
  140. ACPI_EXPORT_SYMBOL(acpi_get_handle)
  141.  
  142. /******************************************************************************
  143.  *
  144.  * FUNCTION:    acpi_get_name
  145.  *
  146.  * PARAMETERS:  handle          - Handle to be converted to a pathname
  147.  *              name_type       - Full pathname or single segment
  148.  *              buffer          - Buffer for returned path
  149.  *
  150.  * RETURN:      Pointer to a string containing the fully qualified Name.
  151.  *
  152.  * DESCRIPTION: This routine returns the fully qualified name associated with
  153.  *              the Handle parameter. This and the acpi_pathname_to_handle are
  154.  *              complementary functions.
  155.  *
  156.  ******************************************************************************/
  157. acpi_status
  158. acpi_get_name(acpi_handle handle, u32 name_type, struct acpi_buffer * buffer)
  159. {
  160.         acpi_status status;
  161.         struct acpi_namespace_node *node;
  162.         char *node_name;
  163.  
  164.         /* Parameter validation */
  165.  
  166.         if (name_type > ACPI_NAME_TYPE_MAX) {
  167.                 return (AE_BAD_PARAMETER);
  168.         }
  169.  
  170.         status = acpi_ut_validate_buffer(buffer);
  171.         if (ACPI_FAILURE(status)) {
  172.                 return (status);
  173.         }
  174.  
  175.         if (name_type == ACPI_FULL_PATHNAME ||
  176.             name_type == ACPI_FULL_PATHNAME_NO_TRAILING) {
  177.  
  178.                 /* Get the full pathname (From the namespace root) */
  179.  
  180.                 status = acpi_ns_handle_to_pathname(handle, buffer,
  181.                                                     name_type ==
  182.                                                     ACPI_FULL_PATHNAME ? FALSE :
  183.                                                     TRUE);
  184.                 return (status);
  185.         }
  186.  
  187.         /*
  188.          * Wants the single segment ACPI name.
  189.          * Validate handle and convert to a namespace Node
  190.          */
  191.         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
  192.         if (ACPI_FAILURE(status)) {
  193.                 return (status);
  194.         }
  195.  
  196.         node = acpi_ns_validate_handle(handle);
  197.         if (!node) {
  198.                 status = AE_BAD_PARAMETER;
  199.                 goto unlock_and_exit;
  200.         }
  201.  
  202.         /* Validate/Allocate/Clear caller buffer */
  203.  
  204.         status = acpi_ut_initialize_buffer(buffer, ACPI_PATH_SEGMENT_LENGTH);
  205.         if (ACPI_FAILURE(status)) {
  206.                 goto unlock_and_exit;
  207.         }
  208.  
  209.         /* Just copy the ACPI name from the Node and zero terminate it */
  210.  
  211.         node_name = acpi_ut_get_node_name(node);
  212.         ACPI_MOVE_NAME(buffer->pointer, node_name);
  213.         ((char *)buffer->pointer)[ACPI_NAME_SIZE] = 0;
  214.         status = AE_OK;
  215.  
  216. unlock_and_exit:
  217.  
  218.         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
  219.         return (status);
  220. }
  221.  
  222. ACPI_EXPORT_SYMBOL(acpi_get_name)
  223.  
  224. /******************************************************************************
  225.  *
  226.  * FUNCTION:    acpi_ns_copy_device_id
  227.  *
  228.  * PARAMETERS:  dest                - Pointer to the destination PNP_DEVICE_ID
  229.  *              source              - Pointer to the source PNP_DEVICE_ID
  230.  *              string_area         - Pointer to where to copy the dest string
  231.  *
  232.  * RETURN:      Pointer to the next string area
  233.  *
  234.  * DESCRIPTION: Copy a single PNP_DEVICE_ID, including the string data.
  235.  *
  236.  ******************************************************************************/
  237. static char *acpi_ns_copy_device_id(struct acpi_pnp_device_id *dest,
  238.                                     struct acpi_pnp_device_id *source,
  239.                                     char *string_area)
  240. {
  241.  
  242.         /* Create the destination PNP_DEVICE_ID */
  243.  
  244.         dest->string = string_area;
  245.         dest->length = source->length;
  246.  
  247.         /* Copy actual string and return a pointer to the next string area */
  248.  
  249.         memcpy(string_area, source->string, source->length);
  250.         return (string_area + source->length);
  251. }
  252.  
  253. /******************************************************************************
  254.  *
  255.  * FUNCTION:    acpi_get_object_info
  256.  *
  257.  * PARAMETERS:  handle              - Object Handle
  258.  *              return_buffer       - Where the info is returned
  259.  *
  260.  * RETURN:      Status
  261.  *
  262.  * DESCRIPTION: Returns information about an object as gleaned from the
  263.  *              namespace node and possibly by running several standard
  264.  *              control methods (Such as in the case of a device.)
  265.  *
  266.  * For Device and Processor objects, run the Device _HID, _UID, _CID, _SUB,
  267.  * _CLS, _STA, _ADR, _sx_w, and _sx_d methods.
  268.  *
  269.  * Note: Allocates the return buffer, must be freed by the caller.
  270.  *
  271.  ******************************************************************************/
  272.  
  273. acpi_status
  274. acpi_get_object_info(acpi_handle handle,
  275.                      struct acpi_device_info **return_buffer)
  276. {
  277.         struct acpi_namespace_node *node;
  278.         struct acpi_device_info *info;
  279.         struct acpi_pnp_device_id_list *cid_list = NULL;
  280.         struct acpi_pnp_device_id *hid = NULL;
  281.         struct acpi_pnp_device_id *uid = NULL;
  282.         struct acpi_pnp_device_id *sub = NULL;
  283.         struct acpi_pnp_device_id *cls = NULL;
  284.         char *next_id_string;
  285.         acpi_object_type type;
  286.         acpi_name name;
  287.         u8 param_count = 0;
  288.         u16 valid = 0;
  289.         u32 info_size;
  290.         u32 i;
  291.         acpi_status status;
  292.  
  293.         /* Parameter validation */
  294.  
  295.         if (!handle || !return_buffer) {
  296.                 return (AE_BAD_PARAMETER);
  297.         }
  298.  
  299.         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
  300.         if (ACPI_FAILURE(status)) {
  301.                 return (status);
  302.         }
  303.  
  304.         node = acpi_ns_validate_handle(handle);
  305.         if (!node) {
  306.                 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
  307.                 return (AE_BAD_PARAMETER);
  308.         }
  309.  
  310.         /* Get the namespace node data while the namespace is locked */
  311.  
  312.         info_size = sizeof(struct acpi_device_info);
  313.         type = node->type;
  314.         name = node->name.integer;
  315.  
  316.         if (node->type == ACPI_TYPE_METHOD) {
  317.                 param_count = node->object->method.param_count;
  318.         }
  319.  
  320.         status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
  321.         if (ACPI_FAILURE(status)) {
  322.                 return (status);
  323.         }
  324.  
  325.         if ((type == ACPI_TYPE_DEVICE) || (type == ACPI_TYPE_PROCESSOR)) {
  326.                 /*
  327.                  * Get extra info for ACPI Device/Processor objects only:
  328.                  * Run the Device _HID, _UID, _SUB, _CID, and _CLS methods.
  329.                  *
  330.                  * Note: none of these methods are required, so they may or may
  331.                  * not be present for this device. The Info->Valid bitfield is used
  332.                  * to indicate which methods were found and run successfully.
  333.                  */
  334.  
  335.                 /* Execute the Device._HID method */
  336.  
  337.                 status = acpi_ut_execute_HID(node, &hid);
  338.                 if (ACPI_SUCCESS(status)) {
  339.                         info_size += hid->length;
  340.                         valid |= ACPI_VALID_HID;
  341.                 }
  342.  
  343.                 /* Execute the Device._UID method */
  344.  
  345.                 status = acpi_ut_execute_UID(node, &uid);
  346.                 if (ACPI_SUCCESS(status)) {
  347.                         info_size += uid->length;
  348.                         valid |= ACPI_VALID_UID;
  349.                 }
  350.  
  351.                 /* Execute the Device._SUB method */
  352.  
  353.                 status = acpi_ut_execute_SUB(node, &sub);
  354.                 if (ACPI_SUCCESS(status)) {
  355.                         info_size += sub->length;
  356.                         valid |= ACPI_VALID_SUB;
  357.                 }
  358.  
  359.                 /* Execute the Device._CID method */
  360.  
  361.                 status = acpi_ut_execute_CID(node, &cid_list);
  362.                 if (ACPI_SUCCESS(status)) {
  363.  
  364.                         /* Add size of CID strings and CID pointer array */
  365.  
  366.                         info_size +=
  367.                             (cid_list->list_size -
  368.                              sizeof(struct acpi_pnp_device_id_list));
  369.                         valid |= ACPI_VALID_CID;
  370.                 }
  371.  
  372.                 /* Execute the Device._CLS method */
  373.  
  374.                 status = acpi_ut_execute_CLS(node, &cls);
  375.                 if (ACPI_SUCCESS(status)) {
  376.                         info_size += cls->length;
  377.                         valid |= ACPI_VALID_CLS;
  378.                 }
  379.         }
  380.  
  381.         /*
  382.          * Now that we have the variable-length data, we can allocate the
  383.          * return buffer
  384.          */
  385.         info = ACPI_ALLOCATE_ZEROED(info_size);
  386.         if (!info) {
  387.                 status = AE_NO_MEMORY;
  388.                 goto cleanup;
  389.         }
  390.  
  391.         /* Get the fixed-length data */
  392.  
  393.         if ((type == ACPI_TYPE_DEVICE) || (type == ACPI_TYPE_PROCESSOR)) {
  394.                 /*
  395.                  * Get extra info for ACPI Device/Processor objects only:
  396.                  * Run the _STA, _ADR and, sx_w, and _sx_d methods.
  397.                  *
  398.                  * Notes: none of these methods are required, so they may or may
  399.                  * not be present for this device. The Info->Valid bitfield is used
  400.                  * to indicate which methods were found and run successfully.
  401.                  *
  402.                  * For _STA, if the method does not exist, then (as per the ACPI
  403.                  * specification), the returned current_status flags will indicate
  404.                  * that the device is present/functional/enabled. Otherwise, the
  405.                  * current_status flags reflect the value returned from _STA.
  406.                  */
  407.  
  408.                 /* Execute the Device._STA method */
  409.  
  410.                 status = acpi_ut_execute_STA(node, &info->current_status);
  411.                 if (ACPI_SUCCESS(status)) {
  412.                         valid |= ACPI_VALID_STA;
  413.                 }
  414.  
  415.                 /* Execute the Device._ADR method */
  416.  
  417.                 status = acpi_ut_evaluate_numeric_object(METHOD_NAME__ADR, node,
  418.                                                          &info->address);
  419.                 if (ACPI_SUCCESS(status)) {
  420.                         valid |= ACPI_VALID_ADR;
  421.                 }
  422.  
  423.                 /* Execute the Device._sx_w methods */
  424.  
  425.                 status = acpi_ut_execute_power_methods(node,
  426.                                                        acpi_gbl_lowest_dstate_names,
  427.                                                        ACPI_NUM_sx_w_METHODS,
  428.                                                        info->lowest_dstates);
  429.                 if (ACPI_SUCCESS(status)) {
  430.                         valid |= ACPI_VALID_SXWS;
  431.                 }
  432.  
  433.                 /* Execute the Device._sx_d methods */
  434.  
  435.                 status = acpi_ut_execute_power_methods(node,
  436.                                                        acpi_gbl_highest_dstate_names,
  437.                                                        ACPI_NUM_sx_d_METHODS,
  438.                                                        info->highest_dstates);
  439.                 if (ACPI_SUCCESS(status)) {
  440.                         valid |= ACPI_VALID_SXDS;
  441.                 }
  442.         }
  443.  
  444.         /*
  445.          * Create a pointer to the string area of the return buffer.
  446.          * Point to the end of the base struct acpi_device_info structure.
  447.          */
  448.         next_id_string = ACPI_CAST_PTR(char, info->compatible_id_list.ids);
  449.         if (cid_list) {
  450.  
  451.                 /* Point past the CID PNP_DEVICE_ID array */
  452.  
  453.                 next_id_string +=
  454.                     ((acpi_size) cid_list->count *
  455.                      sizeof(struct acpi_pnp_device_id));
  456.         }
  457.  
  458.         /*
  459.          * Copy the HID, UID, SUB, and CIDs to the return buffer.
  460.          * The variable-length strings are copied to the reserved area
  461.          * at the end of the buffer.
  462.          *
  463.          * For HID and CID, check if the ID is a PCI Root Bridge.
  464.          */
  465.         if (hid) {
  466.                 next_id_string = acpi_ns_copy_device_id(&info->hardware_id,
  467.                                                         hid, next_id_string);
  468.  
  469.                 if (acpi_ut_is_pci_root_bridge(hid->string)) {
  470.                         info->flags |= ACPI_PCI_ROOT_BRIDGE;
  471.                 }
  472.         }
  473.  
  474.         if (uid) {
  475.                 next_id_string = acpi_ns_copy_device_id(&info->unique_id,
  476.                                                         uid, next_id_string);
  477.         }
  478.  
  479.         if (sub) {
  480.                 next_id_string = acpi_ns_copy_device_id(&info->subsystem_id,
  481.                                                         sub, next_id_string);
  482.         }
  483.  
  484.         if (cid_list) {
  485.                 info->compatible_id_list.count = cid_list->count;
  486.                 info->compatible_id_list.list_size = cid_list->list_size;
  487.  
  488.                 /* Copy each CID */
  489.  
  490.                 for (i = 0; i < cid_list->count; i++) {
  491.                         next_id_string =
  492.                             acpi_ns_copy_device_id(&info->compatible_id_list.
  493.                                                    ids[i], &cid_list->ids[i],
  494.                                                    next_id_string);
  495.  
  496.                         if (acpi_ut_is_pci_root_bridge(cid_list->ids[i].string)) {
  497.                                 info->flags |= ACPI_PCI_ROOT_BRIDGE;
  498.                         }
  499.                 }
  500.         }
  501.  
  502.         if (cls) {
  503.                 next_id_string = acpi_ns_copy_device_id(&info->class_code,
  504.                                                         cls, next_id_string);
  505.         }
  506.  
  507.         /* Copy the fixed-length data */
  508.  
  509.         info->info_size = info_size;
  510.         info->type = type;
  511.         info->name = name;
  512.         info->param_count = param_count;
  513.         info->valid = valid;
  514.  
  515.         *return_buffer = info;
  516.         status = AE_OK;
  517.  
  518. cleanup:
  519.         if (hid) {
  520.                 ACPI_FREE(hid);
  521.         }
  522.         if (uid) {
  523.                 ACPI_FREE(uid);
  524.         }
  525.         if (sub) {
  526.                 ACPI_FREE(sub);
  527.         }
  528.         if (cid_list) {
  529.                 ACPI_FREE(cid_list);
  530.         }
  531.         if (cls) {
  532.                 ACPI_FREE(cls);
  533.         }
  534.         return (status);
  535. }
  536.  
  537. ACPI_EXPORT_SYMBOL(acpi_get_object_info)
  538.  
  539. /******************************************************************************
  540.  *
  541.  * FUNCTION:    acpi_install_method
  542.  *
  543.  * PARAMETERS:  buffer         - An ACPI table containing one control method
  544.  *
  545.  * RETURN:      Status
  546.  *
  547.  * DESCRIPTION: Install a control method into the namespace. If the method
  548.  *              name already exists in the namespace, it is overwritten. The
  549.  *              input buffer must contain a valid DSDT or SSDT containing a
  550.  *              single control method.
  551.  *
  552.  ******************************************************************************/
  553. acpi_status acpi_install_method(u8 *buffer)
  554. {
  555.         struct acpi_table_header *table =
  556.             ACPI_CAST_PTR(struct acpi_table_header, buffer);
  557.         u8 *aml_buffer;
  558.         u8 *aml_start;
  559.         char *path;
  560.         struct acpi_namespace_node *node;
  561.         union acpi_operand_object *method_obj;
  562.         struct acpi_parse_state parser_state;
  563.         u32 aml_length;
  564.         u16 opcode;
  565.         u8 method_flags;
  566.         acpi_status status;
  567.  
  568.         /* Parameter validation */
  569.  
  570.         if (!buffer) {
  571.                 return (AE_BAD_PARAMETER);
  572.         }
  573.  
  574.         /* Table must be a DSDT or SSDT */
  575.  
  576.         if (!ACPI_COMPARE_NAME(table->signature, ACPI_SIG_DSDT) &&
  577.             !ACPI_COMPARE_NAME(table->signature, ACPI_SIG_SSDT)) {
  578.                 return (AE_BAD_HEADER);
  579.         }
  580.  
  581.         /* First AML opcode in the table must be a control method */
  582.  
  583.         parser_state.aml = buffer + sizeof(struct acpi_table_header);
  584.         opcode = acpi_ps_peek_opcode(&parser_state);
  585.         if (opcode != AML_METHOD_OP) {
  586.                 return (AE_BAD_PARAMETER);
  587.         }
  588.  
  589.         /* Extract method information from the raw AML */
  590.  
  591.         parser_state.aml += acpi_ps_get_opcode_size(opcode);
  592.         parser_state.pkg_end = acpi_ps_get_next_package_end(&parser_state);
  593.         path = acpi_ps_get_next_namestring(&parser_state);
  594.         method_flags = *parser_state.aml++;
  595.         aml_start = parser_state.aml;
  596.         aml_length = ACPI_PTR_DIFF(parser_state.pkg_end, aml_start);
  597.  
  598.         /*
  599.          * Allocate resources up-front. We don't want to have to delete a new
  600.          * node from the namespace if we cannot allocate memory.
  601.          */
  602.         aml_buffer = ACPI_ALLOCATE(aml_length);
  603.         if (!aml_buffer) {
  604.                 return (AE_NO_MEMORY);
  605.         }
  606.  
  607.         method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
  608.         if (!method_obj) {
  609.                 ACPI_FREE(aml_buffer);
  610.                 return (AE_NO_MEMORY);
  611.         }
  612.  
  613.         /* Lock namespace for acpi_ns_lookup, we may be creating a new node */
  614.  
  615.         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
  616.         if (ACPI_FAILURE(status)) {
  617.                 goto error_exit;
  618.         }
  619.  
  620.         /* The lookup either returns an existing node or creates a new one */
  621.  
  622.         status =
  623.             acpi_ns_lookup(NULL, path, ACPI_TYPE_METHOD, ACPI_IMODE_LOAD_PASS1,
  624.                            ACPI_NS_DONT_OPEN_SCOPE | ACPI_NS_ERROR_IF_FOUND,
  625.                            NULL, &node);
  626.  
  627.         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
  628.  
  629.         if (ACPI_FAILURE(status)) {     /* ns_lookup */
  630.                 if (status != AE_ALREADY_EXISTS) {
  631.                         goto error_exit;
  632.                 }
  633.  
  634.                 /* Node existed previously, make sure it is a method node */
  635.  
  636.                 if (node->type != ACPI_TYPE_METHOD) {
  637.                         status = AE_TYPE;
  638.                         goto error_exit;
  639.                 }
  640.         }
  641.  
  642.         /* Copy the method AML to the local buffer */
  643.  
  644.         memcpy(aml_buffer, aml_start, aml_length);
  645.  
  646.         /* Initialize the method object with the new method's information */
  647.  
  648.         method_obj->method.aml_start = aml_buffer;
  649.         method_obj->method.aml_length = aml_length;
  650.  
  651.         method_obj->method.param_count = (u8)
  652.             (method_flags & AML_METHOD_ARG_COUNT);
  653.  
  654.         if (method_flags & AML_METHOD_SERIALIZED) {
  655.                 method_obj->method.info_flags = ACPI_METHOD_SERIALIZED;
  656.  
  657.                 method_obj->method.sync_level = (u8)
  658.                     ((method_flags & AML_METHOD_SYNC_LEVEL) >> 4);
  659.         }
  660.  
  661.         /*
  662.          * Now that it is complete, we can attach the new method object to
  663.          * the method Node (detaches/deletes any existing object)
  664.          */
  665.         status = acpi_ns_attach_object(node, method_obj, ACPI_TYPE_METHOD);
  666.  
  667.         /*
  668.          * Flag indicates AML buffer is dynamic, must be deleted later.
  669.          * Must be set only after attach above.
  670.          */
  671.         node->flags |= ANOBJ_ALLOCATED_BUFFER;
  672.  
  673.         /* Remove local reference to the method object */
  674.  
  675.         acpi_ut_remove_reference(method_obj);
  676.         return (status);
  677.  
  678. error_exit:
  679.  
  680.         ACPI_FREE(aml_buffer);
  681.         ACPI_FREE(method_obj);
  682.         return (status);
  683. }
  684. ACPI_EXPORT_SYMBOL(acpi_install_method)
  685.