Subversion Repositories Kolibri OS

Rev

Go to most recent revision | Blame | Last modification | View Log | Download | RSS feed

  1. /******************************************************************************
  2.  *
  3.  * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
  4.  *
  5.  *****************************************************************************/
  6.  
  7. /*
  8.  * Copyright (C) 2000 - 2015, Intel Corp.
  9.  * All rights reserved.
  10.  *
  11.  * Redistribution and use in source and binary forms, with or without
  12.  * modification, are permitted provided that the following conditions
  13.  * are met:
  14.  * 1. Redistributions of source code must retain the above copyright
  15.  *    notice, this list of conditions, and the following disclaimer,
  16.  *    without modification.
  17.  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18.  *    substantially similar to the "NO WARRANTY" disclaimer below
  19.  *    ("Disclaimer") and any redistribution must be conditioned upon
  20.  *    including a substantially similar Disclaimer requirement for further
  21.  *    binary redistribution.
  22.  * 3. Neither the names of the above-listed copyright holders nor the names
  23.  *    of any contributors may be used to endorse or promote products derived
  24.  *    from this software without specific prior written permission.
  25.  *
  26.  * Alternatively, this software may be distributed under the terms of the
  27.  * GNU General Public License ("GPL") version 2 as published by the Free
  28.  * Software Foundation.
  29.  *
  30.  * NO WARRANTY
  31.  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32.  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33.  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34.  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35.  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36.  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37.  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38.  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39.  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40.  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41.  * POSSIBILITY OF SUCH DAMAGES.
  42.  */
  43.  
  44. #include <acpi/acpi.h>
  45. #include "accommon.h"
  46. #include "acdispat.h"
  47. #include "acinterp.h"
  48. #include "acnamesp.h"
  49. #include "acparser.h"
  50. #include "amlcode.h"
  51. #include "acdebug.h"
  52.  
  53. #define _COMPONENT          ACPI_DISPATCHER
  54. ACPI_MODULE_NAME("dsmethod")
  55.  
  56. /* Local prototypes */
  57. static acpi_status
  58. acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
  59.                              union acpi_parse_object **out_op);
  60.  
  61. static acpi_status
  62. acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
  63.  
  64. /*******************************************************************************
  65.  *
  66.  * FUNCTION:    acpi_ds_auto_serialize_method
  67.  *
  68.  * PARAMETERS:  node                        - Namespace Node of the method
  69.  *              obj_desc                    - Method object attached to node
  70.  *
  71.  * RETURN:      Status
  72.  *
  73.  * DESCRIPTION: Parse a control method AML to scan for control methods that
  74.  *              need serialization due to the creation of named objects.
  75.  *
  76.  * NOTE: It is a bit of overkill to mark all such methods serialized, since
  77.  * there is only a problem if the method actually blocks during execution.
  78.  * A blocking operation is, for example, a Sleep() operation, or any access
  79.  * to an operation region. However, it is probably not possible to easily
  80.  * detect whether a method will block or not, so we simply mark all suspicious
  81.  * methods as serialized.
  82.  *
  83.  * NOTE2: This code is essentially a generic routine for parsing a single
  84.  * control method.
  85.  *
  86.  ******************************************************************************/
  87.  
  88. acpi_status
  89. acpi_ds_auto_serialize_method(struct acpi_namespace_node *node,
  90.                               union acpi_operand_object *obj_desc)
  91. {
  92.         acpi_status status;
  93.         union acpi_parse_object *op = NULL;
  94.         struct acpi_walk_state *walk_state;
  95.  
  96.         ACPI_FUNCTION_TRACE_PTR(ds_auto_serialize_method, node);
  97.  
  98.         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
  99.                           "Method auto-serialization parse [%4.4s] %p\n",
  100.                           acpi_ut_get_node_name(node), node));
  101.  
  102.         /* Create/Init a root op for the method parse tree */
  103.  
  104.         op = acpi_ps_alloc_op(AML_METHOD_OP, obj_desc->method.aml_start);
  105.         if (!op) {
  106.                 return_ACPI_STATUS(AE_NO_MEMORY);
  107.         }
  108.  
  109.         acpi_ps_set_name(op, node->name.integer);
  110.         op->common.node = node;
  111.  
  112.         /* Create and initialize a new walk state */
  113.  
  114.         walk_state =
  115.             acpi_ds_create_walk_state(node->owner_id, NULL, NULL, NULL);
  116.         if (!walk_state) {
  117.                 acpi_ps_free_op(op);
  118.                 return_ACPI_STATUS(AE_NO_MEMORY);
  119.         }
  120.  
  121.         status =
  122.             acpi_ds_init_aml_walk(walk_state, op, node,
  123.                                   obj_desc->method.aml_start,
  124.                                   obj_desc->method.aml_length, NULL, 0);
  125.         if (ACPI_FAILURE(status)) {
  126.                 acpi_ds_delete_walk_state(walk_state);
  127.                 acpi_ps_free_op(op);
  128.                 return_ACPI_STATUS(status);
  129.         }
  130.  
  131.         walk_state->descending_callback = acpi_ds_detect_named_opcodes;
  132.  
  133.         /* Parse the method, scan for creation of named objects */
  134.  
  135.         status = acpi_ps_parse_aml(walk_state);
  136.  
  137.         acpi_ps_delete_parse_tree(op);
  138.         return_ACPI_STATUS(status);
  139. }
  140.  
  141. /*******************************************************************************
  142.  *
  143.  * FUNCTION:    acpi_ds_detect_named_opcodes
  144.  *
  145.  * PARAMETERS:  walk_state      - Current state of the parse tree walk
  146.  *              out_op          - Unused, required for parser interface
  147.  *
  148.  * RETURN:      Status
  149.  *
  150.  * DESCRIPTION: Descending callback used during the loading of ACPI tables.
  151.  *              Currently used to detect methods that must be marked serialized
  152.  *              in order to avoid problems with the creation of named objects.
  153.  *
  154.  ******************************************************************************/
  155.  
  156. static acpi_status
  157. acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
  158.                              union acpi_parse_object **out_op)
  159. {
  160.  
  161.         ACPI_FUNCTION_NAME(acpi_ds_detect_named_opcodes);
  162.  
  163.         /* We are only interested in opcodes that create a new name */
  164.  
  165.         if (!
  166.             (walk_state->op_info->
  167.              flags & (AML_NAMED | AML_CREATE | AML_FIELD))) {
  168.                 return (AE_OK);
  169.         }
  170.  
  171.         /*
  172.          * At this point, we know we have a Named object opcode.
  173.          * Mark the method as serialized. Later code will create a mutex for
  174.          * this method to enforce serialization.
  175.          *
  176.          * Note, ACPI_METHOD_IGNORE_SYNC_LEVEL flag means that we will ignore the
  177.          * Sync Level mechanism for this method, even though it is now serialized.
  178.          * Otherwise, there can be conflicts with existing ASL code that actually
  179.          * uses sync levels.
  180.          */
  181.         walk_state->method_desc->method.sync_level = 0;
  182.         walk_state->method_desc->method.info_flags |=
  183.             (ACPI_METHOD_SERIALIZED | ACPI_METHOD_IGNORE_SYNC_LEVEL);
  184.  
  185.         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  186.                           "Method serialized [%4.4s] %p - [%s] (%4.4X)\n",
  187.                           walk_state->method_node->name.ascii,
  188.                           walk_state->method_node, walk_state->op_info->name,
  189.                           walk_state->opcode));
  190.  
  191.         /* Abort the parse, no need to examine this method any further */
  192.  
  193.         return (AE_CTRL_TERMINATE);
  194. }
  195.  
  196. /*******************************************************************************
  197.  *
  198.  * FUNCTION:    acpi_ds_method_error
  199.  *
  200.  * PARAMETERS:  status          - Execution status
  201.  *              walk_state      - Current state
  202.  *
  203.  * RETURN:      Status
  204.  *
  205.  * DESCRIPTION: Called on method error. Invoke the global exception handler if
  206.  *              present, dump the method data if the debugger is configured
  207.  *
  208.  *              Note: Allows the exception handler to change the status code
  209.  *
  210.  ******************************************************************************/
  211.  
  212. acpi_status
  213. acpi_ds_method_error(acpi_status status, struct acpi_walk_state * walk_state)
  214. {
  215.         u32 aml_offset;
  216.  
  217.         ACPI_FUNCTION_ENTRY();
  218.  
  219.         /* Ignore AE_OK and control exception codes */
  220.  
  221.         if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
  222.                 return (status);
  223.         }
  224.  
  225.         /* Invoke the global exception handler */
  226.  
  227.         if (acpi_gbl_exception_handler) {
  228.  
  229.                 /* Exit the interpreter, allow handler to execute methods */
  230.  
  231.                 acpi_ex_exit_interpreter();
  232.  
  233.                 /*
  234.                  * Handler can map the exception code to anything it wants, including
  235.                  * AE_OK, in which case the executing method will not be aborted.
  236.                  */
  237.                 aml_offset = (u32)ACPI_PTR_DIFF(walk_state->aml,
  238.                                                 walk_state->parser_state.
  239.                                                 aml_start);
  240.  
  241.                 status = acpi_gbl_exception_handler(status,
  242.                                                     walk_state->method_node ?
  243.                                                     walk_state->method_node->
  244.                                                     name.integer : 0,
  245.                                                     walk_state->opcode,
  246.                                                     aml_offset, NULL);
  247.                 acpi_ex_enter_interpreter();
  248.         }
  249.  
  250.         acpi_ds_clear_implicit_return(walk_state);
  251.  
  252.         if (ACPI_FAILURE(status)) {
  253.                 acpi_ds_dump_method_stack(status, walk_state, walk_state->op);
  254.  
  255.                 /* Display method locals/args if debugger is present */
  256.  
  257. #ifdef ACPI_DEBUGGER
  258.                 acpi_db_dump_method_info(status, walk_state);
  259. #endif
  260.         }
  261.  
  262.         return (status);
  263. }
  264.  
  265. /*******************************************************************************
  266.  *
  267.  * FUNCTION:    acpi_ds_create_method_mutex
  268.  *
  269.  * PARAMETERS:  obj_desc            - The method object
  270.  *
  271.  * RETURN:      Status
  272.  *
  273.  * DESCRIPTION: Create a mutex object for a serialized control method
  274.  *
  275.  ******************************************************************************/
  276.  
  277. static acpi_status
  278. acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
  279. {
  280.         union acpi_operand_object *mutex_desc;
  281.         acpi_status status;
  282.  
  283.         ACPI_FUNCTION_TRACE(ds_create_method_mutex);
  284.  
  285.         /* Create the new mutex object */
  286.  
  287.         mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
  288.         if (!mutex_desc) {
  289.                 return_ACPI_STATUS(AE_NO_MEMORY);
  290.         }
  291.  
  292.         /* Create the actual OS Mutex */
  293.  
  294.         status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
  295.         if (ACPI_FAILURE(status)) {
  296.                 acpi_ut_delete_object_desc(mutex_desc);
  297.                 return_ACPI_STATUS(status);
  298.         }
  299.  
  300.         mutex_desc->mutex.sync_level = method_desc->method.sync_level;
  301.         method_desc->method.mutex = mutex_desc;
  302.         return_ACPI_STATUS(AE_OK);
  303. }
  304.  
  305. /*******************************************************************************
  306.  *
  307.  * FUNCTION:    acpi_ds_begin_method_execution
  308.  *
  309.  * PARAMETERS:  method_node         - Node of the method
  310.  *              obj_desc            - The method object
  311.  *              walk_state          - current state, NULL if not yet executing
  312.  *                                    a method.
  313.  *
  314.  * RETURN:      Status
  315.  *
  316.  * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
  317.  *              increments the thread count, and waits at the method semaphore
  318.  *              for clearance to execute.
  319.  *
  320.  ******************************************************************************/
  321.  
  322. acpi_status
  323. acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
  324.                                union acpi_operand_object *obj_desc,
  325.                                struct acpi_walk_state *walk_state)
  326. {
  327.         acpi_status status = AE_OK;
  328.  
  329.         ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
  330.  
  331.         if (!method_node) {
  332.                 return_ACPI_STATUS(AE_NULL_ENTRY);
  333.         }
  334.  
  335.         acpi_ex_start_trace_method(method_node, obj_desc, walk_state);
  336.  
  337.         /* Prevent wraparound of thread count */
  338.  
  339.         if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
  340.                 ACPI_ERROR((AE_INFO,
  341.                             "Method reached maximum reentrancy limit (255)"));
  342.                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
  343.         }
  344.  
  345.         /*
  346.          * If this method is serialized, we need to acquire the method mutex.
  347.          */
  348.         if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
  349.                 /*
  350.                  * Create a mutex for the method if it is defined to be Serialized
  351.                  * and a mutex has not already been created. We defer the mutex creation
  352.                  * until a method is actually executed, to minimize the object count
  353.                  */
  354.                 if (!obj_desc->method.mutex) {
  355.                         status = acpi_ds_create_method_mutex(obj_desc);
  356.                         if (ACPI_FAILURE(status)) {
  357.                                 return_ACPI_STATUS(status);
  358.                         }
  359.                 }
  360.  
  361.                 /*
  362.                  * The current_sync_level (per-thread) must be less than or equal to
  363.                  * the sync level of the method. This mechanism provides some
  364.                  * deadlock prevention.
  365.                  *
  366.                  * If the method was auto-serialized, we just ignore the sync level
  367.                  * mechanism, because auto-serialization of methods can interfere
  368.                  * with ASL code that actually uses sync levels.
  369.                  *
  370.                  * Top-level method invocation has no walk state at this point
  371.                  */
  372.                 if (walk_state &&
  373.                     (!(obj_desc->method.
  374.                        info_flags & ACPI_METHOD_IGNORE_SYNC_LEVEL))
  375.                     && (walk_state->thread->current_sync_level >
  376.                         obj_desc->method.mutex->mutex.sync_level)) {
  377.                         ACPI_ERROR((AE_INFO,
  378.                                     "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)",
  379.                                     acpi_ut_get_node_name(method_node),
  380.                                     walk_state->thread->current_sync_level));
  381.  
  382.                         return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
  383.                 }
  384.  
  385.                 /*
  386.                  * Obtain the method mutex if necessary. Do not acquire mutex for a
  387.                  * recursive call.
  388.                  */
  389.                 if (!walk_state ||
  390.                     !obj_desc->method.mutex->mutex.thread_id ||
  391.                     (walk_state->thread->thread_id !=
  392.                      obj_desc->method.mutex->mutex.thread_id)) {
  393.                         /*
  394.                          * Acquire the method mutex. This releases the interpreter if we
  395.                          * block (and reacquires it before it returns)
  396.                          */
  397.                         status =
  398.                             acpi_ex_system_wait_mutex(obj_desc->method.mutex->
  399.                                                       mutex.os_mutex,
  400.                                                       ACPI_WAIT_FOREVER);
  401.                         if (ACPI_FAILURE(status)) {
  402.                                 return_ACPI_STATUS(status);
  403.                         }
  404.  
  405.                         /* Update the mutex and walk info and save the original sync_level */
  406.  
  407.                         if (walk_state) {
  408.                                 obj_desc->method.mutex->mutex.
  409.                                     original_sync_level =
  410.                                     walk_state->thread->current_sync_level;
  411.  
  412.                                 obj_desc->method.mutex->mutex.thread_id =
  413.                                     walk_state->thread->thread_id;
  414.                                 walk_state->thread->current_sync_level =
  415.                                     obj_desc->method.sync_level;
  416.                         } else {
  417.                                 obj_desc->method.mutex->mutex.
  418.                                     original_sync_level =
  419.                                     obj_desc->method.mutex->mutex.sync_level;
  420.  
  421.                                 obj_desc->method.mutex->mutex.thread_id =
  422.                                     acpi_os_get_thread_id();
  423.                         }
  424.                 }
  425.  
  426.                 /* Always increase acquisition depth */
  427.  
  428.                 obj_desc->method.mutex->mutex.acquisition_depth++;
  429.         }
  430.  
  431.         /*
  432.          * Allocate an Owner ID for this method, only if this is the first thread
  433.          * to begin concurrent execution. We only need one owner_id, even if the
  434.          * method is invoked recursively.
  435.          */
  436.         if (!obj_desc->method.owner_id) {
  437.                 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
  438.                 if (ACPI_FAILURE(status)) {
  439.                         goto cleanup;
  440.                 }
  441.         }
  442.  
  443.         /*
  444.          * Increment the method parse tree thread count since it has been
  445.          * reentered one more time (even if it is the same thread)
  446.          */
  447.         obj_desc->method.thread_count++;
  448.         acpi_method_count++;
  449.         return_ACPI_STATUS(status);
  450.  
  451. cleanup:
  452.         /* On error, must release the method mutex (if present) */
  453.  
  454.         if (obj_desc->method.mutex) {
  455.                 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
  456.         }
  457.         return_ACPI_STATUS(status);
  458. }
  459.  
  460. /*******************************************************************************
  461.  *
  462.  * FUNCTION:    acpi_ds_call_control_method
  463.  *
  464.  * PARAMETERS:  thread              - Info for this thread
  465.  *              this_walk_state     - Current walk state
  466.  *              op                  - Current Op to be walked
  467.  *
  468.  * RETURN:      Status
  469.  *
  470.  * DESCRIPTION: Transfer execution to a called control method
  471.  *
  472.  ******************************************************************************/
  473.  
  474. acpi_status
  475. acpi_ds_call_control_method(struct acpi_thread_state *thread,
  476.                             struct acpi_walk_state *this_walk_state,
  477.                             union acpi_parse_object *op)
  478. {
  479.         acpi_status status;
  480.         struct acpi_namespace_node *method_node;
  481.         struct acpi_walk_state *next_walk_state = NULL;
  482.         union acpi_operand_object *obj_desc;
  483.         struct acpi_evaluate_info *info;
  484.         u32 i;
  485.  
  486.         ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
  487.  
  488.         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
  489.                           "Calling method %p, currentstate=%p\n",
  490.                           this_walk_state->prev_op, this_walk_state));
  491.  
  492.         /*
  493.          * Get the namespace entry for the control method we are about to call
  494.          */
  495.         method_node = this_walk_state->method_call_node;
  496.         if (!method_node) {
  497.                 return_ACPI_STATUS(AE_NULL_ENTRY);
  498.         }
  499.  
  500.         obj_desc = acpi_ns_get_attached_object(method_node);
  501.         if (!obj_desc) {
  502.                 return_ACPI_STATUS(AE_NULL_OBJECT);
  503.         }
  504.  
  505.         /* Init for new method, possibly wait on method mutex */
  506.  
  507.         status = acpi_ds_begin_method_execution(method_node, obj_desc,
  508.                                                 this_walk_state);
  509.         if (ACPI_FAILURE(status)) {
  510.                 return_ACPI_STATUS(status);
  511.         }
  512.  
  513.         /* Begin method parse/execution. Create a new walk state */
  514.  
  515.         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
  516.                                                     NULL, obj_desc, thread);
  517.         if (!next_walk_state) {
  518.                 status = AE_NO_MEMORY;
  519.                 goto cleanup;
  520.         }
  521.  
  522.         /*
  523.          * The resolved arguments were put on the previous walk state's operand
  524.          * stack. Operands on the previous walk state stack always
  525.          * start at index 0. Also, null terminate the list of arguments
  526.          */
  527.         this_walk_state->operands[this_walk_state->num_operands] = NULL;
  528.  
  529.         /*
  530.          * Allocate and initialize the evaluation information block
  531.          * TBD: this is somewhat inefficient, should change interface to
  532.          * ds_init_aml_walk. For now, keeps this struct off the CPU stack
  533.          */
  534.         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
  535.         if (!info) {
  536.                 status = AE_NO_MEMORY;
  537.                 goto cleanup;
  538.         }
  539.  
  540.         info->parameters = &this_walk_state->operands[0];
  541.  
  542.         status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
  543.                                        obj_desc->method.aml_start,
  544.                                        obj_desc->method.aml_length, info,
  545.                                        ACPI_IMODE_EXECUTE);
  546.  
  547.         ACPI_FREE(info);
  548.         if (ACPI_FAILURE(status)) {
  549.                 goto cleanup;
  550.         }
  551.  
  552.         /*
  553.          * Delete the operands on the previous walkstate operand stack
  554.          * (they were copied to new objects)
  555.          */
  556.         for (i = 0; i < obj_desc->method.param_count; i++) {
  557.                 acpi_ut_remove_reference(this_walk_state->operands[i]);
  558.                 this_walk_state->operands[i] = NULL;
  559.         }
  560.  
  561.         /* Clear the operand stack */
  562.  
  563.         this_walk_state->num_operands = 0;
  564.  
  565.         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
  566.                           "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
  567.                           method_node->name.ascii, next_walk_state));
  568.  
  569.         /* Invoke an internal method if necessary */
  570.  
  571.         if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
  572.                 status =
  573.                     obj_desc->method.dispatch.implementation(next_walk_state);
  574.                 if (status == AE_OK) {
  575.                         status = AE_CTRL_TERMINATE;
  576.                 }
  577.         }
  578.  
  579.         return_ACPI_STATUS(status);
  580.  
  581. cleanup:
  582.  
  583.         /* On error, we must terminate the method properly */
  584.  
  585.         acpi_ds_terminate_control_method(obj_desc, next_walk_state);
  586.         acpi_ds_delete_walk_state(next_walk_state);
  587.  
  588.         return_ACPI_STATUS(status);
  589. }
  590.  
  591. /*******************************************************************************
  592.  *
  593.  * FUNCTION:    acpi_ds_restart_control_method
  594.  *
  595.  * PARAMETERS:  walk_state          - State for preempted method (caller)
  596.  *              return_desc         - Return value from the called method
  597.  *
  598.  * RETURN:      Status
  599.  *
  600.  * DESCRIPTION: Restart a method that was preempted by another (nested) method
  601.  *              invocation. Handle the return value (if any) from the callee.
  602.  *
  603.  ******************************************************************************/
  604.  
  605. acpi_status
  606. acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
  607.                                union acpi_operand_object *return_desc)
  608. {
  609.         acpi_status status;
  610.         int same_as_implicit_return;
  611.  
  612.         ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
  613.  
  614.         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
  615.                           "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
  616.                           acpi_ut_get_node_name(walk_state->method_node),
  617.                           walk_state->method_call_op, return_desc));
  618.  
  619.         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
  620.                           "    ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
  621.                           walk_state->return_used,
  622.                           walk_state->results, walk_state));
  623.  
  624.         /* Did the called method return a value? */
  625.  
  626.         if (return_desc) {
  627.  
  628.                 /* Is the implicit return object the same as the return desc? */
  629.  
  630.                 same_as_implicit_return =
  631.                     (walk_state->implicit_return_obj == return_desc);
  632.  
  633.                 /* Are we actually going to use the return value? */
  634.  
  635.                 if (walk_state->return_used) {
  636.  
  637.                         /* Save the return value from the previous method */
  638.  
  639.                         status = acpi_ds_result_push(return_desc, walk_state);
  640.                         if (ACPI_FAILURE(status)) {
  641.                                 acpi_ut_remove_reference(return_desc);
  642.                                 return_ACPI_STATUS(status);
  643.                         }
  644.  
  645.                         /*
  646.                          * Save as THIS method's return value in case it is returned
  647.                          * immediately to yet another method
  648.                          */
  649.                         walk_state->return_desc = return_desc;
  650.                 }
  651.  
  652.                 /*
  653.                  * The following code is the optional support for the so-called
  654.                  * "implicit return". Some AML code assumes that the last value of the
  655.                  * method is "implicitly" returned to the caller, in the absence of an
  656.                  * explicit return value.
  657.                  *
  658.                  * Just save the last result of the method as the return value.
  659.                  *
  660.                  * NOTE: this is optional because the ASL language does not actually
  661.                  * support this behavior.
  662.                  */
  663.                 else if (!acpi_ds_do_implicit_return
  664.                          (return_desc, walk_state, FALSE)
  665.                          || same_as_implicit_return) {
  666.                         /*
  667.                          * Delete the return value if it will not be used by the
  668.                          * calling method or remove one reference if the explicit return
  669.                          * is the same as the implicit return value.
  670.                          */
  671.                         acpi_ut_remove_reference(return_desc);
  672.                 }
  673.         }
  674.  
  675.         return_ACPI_STATUS(AE_OK);
  676. }
  677.  
  678. /*******************************************************************************
  679.  *
  680.  * FUNCTION:    acpi_ds_terminate_control_method
  681.  *
  682.  * PARAMETERS:  method_desc         - Method object
  683.  *              walk_state          - State associated with the method
  684.  *
  685.  * RETURN:      None
  686.  *
  687.  * DESCRIPTION: Terminate a control method. Delete everything that the method
  688.  *              created, delete all locals and arguments, and delete the parse
  689.  *              tree if requested.
  690.  *
  691.  * MUTEX:       Interpreter is locked
  692.  *
  693.  ******************************************************************************/
  694.  
  695. void
  696. acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
  697.                                  struct acpi_walk_state *walk_state)
  698. {
  699.  
  700.         ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
  701.  
  702.         /* method_desc is required, walk_state is optional */
  703.  
  704.         if (!method_desc) {
  705.                 return_VOID;
  706.         }
  707.  
  708.         if (walk_state) {
  709.  
  710.                 /* Delete all arguments and locals */
  711.  
  712.                 acpi_ds_method_data_delete_all(walk_state);
  713.  
  714.                 /*
  715.                  * If method is serialized, release the mutex and restore the
  716.                  * current sync level for this thread
  717.                  */
  718.                 if (method_desc->method.mutex) {
  719.  
  720.                         /* Acquisition Depth handles recursive calls */
  721.  
  722.                         method_desc->method.mutex->mutex.acquisition_depth--;
  723.                         if (!method_desc->method.mutex->mutex.acquisition_depth) {
  724.                                 walk_state->thread->current_sync_level =
  725.                                     method_desc->method.mutex->mutex.
  726.                                     original_sync_level;
  727.  
  728.                                 acpi_os_release_mutex(method_desc->method.
  729.                                                       mutex->mutex.os_mutex);
  730.                                 method_desc->method.mutex->mutex.thread_id = 0;
  731.                         }
  732.                 }
  733.  
  734.                 /*
  735.                  * Delete any namespace objects created anywhere within the
  736.                  * namespace by the execution of this method. Unless:
  737.                  * 1) This method is a module-level executable code method, in which
  738.                  *    case we want make the objects permanent.
  739.                  * 2) There are other threads executing the method, in which case we
  740.                  *    will wait until the last thread has completed.
  741.                  */
  742.                 if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
  743.                     && (method_desc->method.thread_count == 1)) {
  744.  
  745.                         /* Delete any direct children of (created by) this method */
  746.  
  747.                         acpi_ns_delete_namespace_subtree(walk_state->
  748.                                                          method_node);
  749.  
  750.                         /*
  751.                          * Delete any objects that were created by this method
  752.                          * elsewhere in the namespace (if any were created).
  753.                          * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
  754.                          * deletion such that we don't have to perform an entire
  755.                          * namespace walk for every control method execution.
  756.                          */
  757.                         if (method_desc->method.
  758.                             info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
  759.                                 acpi_ns_delete_namespace_by_owner(method_desc->
  760.                                                                   method.
  761.                                                                   owner_id);
  762.                                 method_desc->method.info_flags &=
  763.                                     ~ACPI_METHOD_MODIFIED_NAMESPACE;
  764.                         }
  765.                 }
  766.         }
  767.  
  768.         /* Decrement the thread count on the method */
  769.  
  770.         if (method_desc->method.thread_count) {
  771.                 method_desc->method.thread_count--;
  772.         } else {
  773.                 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
  774.         }
  775.  
  776.         /* Are there any other threads currently executing this method? */
  777.  
  778.         if (method_desc->method.thread_count) {
  779.                 /*
  780.                  * Additional threads. Do not release the owner_id in this case,
  781.                  * we immediately reuse it for the next thread executing this method
  782.                  */
  783.                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
  784.                                   "*** Completed execution of one thread, %u threads remaining\n",
  785.                                   method_desc->method.thread_count));
  786.         } else {
  787.                 /* This is the only executing thread for this method */
  788.  
  789.                 /*
  790.                  * Support to dynamically change a method from not_serialized to
  791.                  * Serialized if it appears that the method is incorrectly written and
  792.                  * does not support multiple thread execution. The best example of this
  793.                  * is if such a method creates namespace objects and blocks. A second
  794.                  * thread will fail with an AE_ALREADY_EXISTS exception.
  795.                  *
  796.                  * This code is here because we must wait until the last thread exits
  797.                  * before marking the method as serialized.
  798.                  */
  799.                 if (method_desc->method.
  800.                     info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
  801.                         if (walk_state) {
  802.                                 ACPI_INFO((AE_INFO,
  803.                                            "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
  804.                                            walk_state->method_node->name.
  805.                                            ascii));
  806.                         }
  807.  
  808.                         /*
  809.                          * Method tried to create an object twice and was marked as
  810.                          * "pending serialized". The probable cause is that the method
  811.                          * cannot handle reentrancy.
  812.                          *
  813.                          * The method was created as not_serialized, but it tried to create
  814.                          * a named object and then blocked, causing the second thread
  815.                          * entrance to begin and then fail. Workaround this problem by
  816.                          * marking the method permanently as Serialized when the last
  817.                          * thread exits here.
  818.                          */
  819.                         method_desc->method.info_flags &=
  820.                             ~ACPI_METHOD_SERIALIZED_PENDING;
  821.                         method_desc->method.info_flags |=
  822.                             (ACPI_METHOD_SERIALIZED |
  823.                              ACPI_METHOD_IGNORE_SYNC_LEVEL);
  824.                         method_desc->method.sync_level = 0;
  825.                 }
  826.  
  827.                 /* No more threads, we can free the owner_id */
  828.  
  829.                 if (!
  830.                     (method_desc->method.
  831.                      info_flags & ACPI_METHOD_MODULE_LEVEL)) {
  832.                         acpi_ut_release_owner_id(&method_desc->method.owner_id);
  833.                 }
  834.         }
  835.  
  836.         acpi_ex_stop_trace_method((struct acpi_namespace_node *)method_desc->
  837.                                   method.node, method_desc, walk_state);
  838.  
  839.         return_VOID;
  840. }
  841.