// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: dsmethod - Parser/Interpreter interface - control method parsing
*
* Copyright (C) 2000 - 2023, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acdispat.h"
#include "acinterp.h"
#include "acnamesp.h"
#include "acparser.h"
#include "amlcode.h"
#include "acdebug.h"
#define _COMPONENT ACPI_DISPATCHER
ACPI_MODULE_NAME("dsmethod")
/* Local prototypes */
static acpi_status
acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
union acpi_parse_object **out_op);
static acpi_status
acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
/*******************************************************************************
*
* FUNCTION: acpi_ds_auto_serialize_method
*
* PARAMETERS: node - Namespace Node of the method
* obj_desc - Method object attached to node
*
* RETURN: Status
*
* DESCRIPTION: Parse a control method AML to scan for control methods that
* need serialization due to the creation of named objects.
*
* NOTE: It is a bit of overkill to mark all such methods serialized, since
* there is only a problem if the method actually blocks during execution.
* A blocking operation is, for example, a Sleep() operation, or any access
* to an operation region. However, it is probably not possible to easily
* detect whether a method will block or not, so we simply mark all suspicious
* methods as serialized.
*
* NOTE2: This code is essentially a generic routine for parsing a single
* control method.
*
******************************************************************************/
acpi_status
acpi_ds_auto_serialize_method(struct acpi_namespace_node *node,
union acpi_operand_object *obj_desc)
{
acpi_status status;
union acpi_parse_object *op = NULL;
struct acpi_walk_state *walk_state;
ACPI_FUNCTION_TRACE_PTR(ds_auto_serialize_method, node);
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"Method auto-serialization parse [%4.4s] %p\n",
acpi_ut_get_node_name(node), node));
/* Create/Init a root op for the method parse tree */
op = acpi_ps_alloc_op(AML_METHOD_OP, obj_desc->method.aml_start);
if (!op) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
acpi_ps_set_name(op, node->name.integer);
op->common.node = node;
/* Create and initialize a new walk state */
walk_state =
acpi_ds_create_walk_state(node->owner_id, NULL, NULL, NULL);
if (!walk_state) {
acpi_ps_free_op(op);
return_ACPI_STATUS(AE_NO_MEMORY);
}
status = acpi_ds_init_aml_walk(walk_state, op, node,
obj_desc->method.aml_start,
obj_desc->method.aml_length, NULL, 0);
if (ACPI_FAILURE(status)) {
acpi_ds_delete_walk_state(walk_state);
acpi_ps_free_op(op);
return_ACPI_STATUS(status);
}
walk_state->descending_callback = acpi_ds_detect_named_opcodes;
/* Parse the method, scan for creation of named objects */
status = acpi_ps_parse_aml(walk_state);
acpi_ps_delete_parse_tree(op);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_detect_named_opcodes
*
* PARAMETERS: walk_state - Current state of the parse tree walk
* out_op - Unused, required for parser interface
*
* RETURN: Status
*
* DESCRIPTION: Descending callback used during the loading of ACPI tables.
* Currently used to detect methods that must be marked serialized
* in order to avoid problems with the creation of named objects.
*
******************************************************************************/
static acpi_status
acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
union acpi_parse_object **out_op)
{
ACPI_FUNCTION_NAME(acpi_ds_detect_named_opcodes);
/* We are only interested in opcodes that create a new name */
if (!
(walk_state->op_info->
flags & (AML_NAMED | AML_CREATE | AML_FIELD))) {
return (AE_OK);
}
/*
* At this point, we know we have a Named object opcode.
* Mark the method as serialized. Later code will create a mutex for
* this method to enforce serialization.
*
* Note, ACPI_METHOD_IGNORE_SYNC_LEVEL flag means that we will ignore the
* Sync Level mechanism for this method, even though it is now serialized.
* Otherwise, there can be conflicts with existing ASL code that actually
* uses sync levels.
*/
walk_state->method_desc->method.sync_level = 0;
walk_state->method_desc->method.info_flags |=
(ACPI_METHOD_SERIALIZED | ACPI_METHOD_IGNORE_SYNC_LEVEL);
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Method serialized [%4.4s] %p - [%s] (%4.4X)\n",
walk_state->method_node->name.ascii,
walk_state->method_node, walk_state->op_info->name,
walk_state->opcode));
/* Abort the parse, no need to examine this method any further */
return (AE_CTRL_TERMINATE);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_method_error
*
* PARAMETERS: status - Execution status
* walk_state - Current state
*
* RETURN: Status
*
* DESCRIPTION: Called on method error. Invoke the global exception handler if
* present, dump the method data if the debugger is configured
*
* Note: Allows the exception handler to change the status code
*
******************************************************************************/
acpi_status
acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
{
u32 aml_offset;
acpi_name name = 0;
ACPI_FUNCTION_ENTRY();
/* Ignore AE_OK and control exception codes */
if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
return (status);
}
/* Invoke the global exception handler */
if (acpi_gbl_exception_handler) {
/* Exit the interpreter, allow handler to execute methods */
acpi_ex_exit_interpreter();
/*
* Handler can map the exception code to anything it wants, including
* AE_OK, in which case the executing method will not be aborted.
*/
aml_offset = (u32)ACPI_PTR_DIFF(walk_state->aml,
walk_state->parser_state.
aml_start);
if (walk_state->method_node) {
name = walk_state->method_node->name.integer;
} else if (walk_state->deferred_node) {
name = walk_state->deferred_node->name.integer;
}
status = acpi_gbl_exception_handler(status, name,
walk_state->opcode,
aml_offset, NULL);
acpi_ex_enter_interpreter();
}
acpi_ds_clear_implicit_return(walk_state);
if (ACPI_FAILURE(status)) {
acpi_ds_dump_method_stack(status, walk_state, walk_state->op);
/* Display method locals/args if debugger is present */
#ifdef ACPI_DEBUGGER
acpi_db_dump_method_info(status, walk_state);
#endif
}
return (status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_create_method_mutex
*
* PARAMETERS: obj_desc - The method object
*
* RETURN: Status
*
* DESCRIPTION: Create a mutex object for a serialized control method
*
******************************************************************************/
static acpi_status
acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
{
union acpi_operand_object *mutex_desc;
acpi_status status;
ACPI_FUNCTION_TRACE(ds_create_method_mutex);
/* Create the new mutex object */
mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
if (!mutex_desc) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
/* Create the actual OS Mutex */
status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
if (ACPI_FAILURE(status)) {
acpi_ut_delete_object_desc(mutex_desc);
return_ACPI_STATUS(status);
}
mutex_desc->mutex.sync_level = method_desc->method.sync_level;
method_desc->method.mutex = mutex_desc;
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_begin_method_execution
*
* PARAMETERS: method_node - Node of the method
* obj_desc - The method object
* walk_state - current state, NULL if not yet executing
* a method.
*
* RETURN: Status
*
* DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
* increments the thread count, and waits at the method semaphore
* for clearance to execute.
*
******************************************************************************/
acpi_status
acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
union acpi_operand_object *obj_desc,
struct acpi_walk_state *walk_state)
{
acpi_status status = AE_OK;
ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
if (!method_node) {
return_ACPI_STATUS(AE_NULL_ENTRY);
}
acpi_ex_start_trace_method(method_node, obj_desc, walk_state);
/* Prevent wraparound of thread count */
if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
ACPI_ERROR((AE_INFO,
"Method reached maximum reentrancy limit (255)"));
return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
}
/*
* If this method is serialized, we need to acquire the method mutex.
*/
if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
/*
* Create a mutex for the method if it is defined to be Serialized
* and a mutex has not already been created. We defer the mutex creation
* until a method is actually executed, to minimize the object count
*/
if (!obj_desc->method.mutex) {
status = acpi_ds_create_method_mutex(obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
}
/*
* The current_sync_level (per-thread) must be less than or equal to
* the sync level of the method. This mechanism provides some
* deadlock prevention.
*
* If the method was auto-serialized, we just ignore the sync level
* mechanism, because auto-serialization of methods can interfere
* with ASL code that actually uses sync levels.
*
* Top-level method invocation has no walk state at this point
*/
if (walk_state &&
(!(obj_desc->method.
info_flags & ACPI_METHOD_IGNORE_SYNC_LEVEL))
&& (walk_state->thread->current_sync_level >
obj_desc->method.mutex->mutex.sync_level)) {
ACPI_ERROR((AE_INFO,
"Cannot acquire Mutex for method [%4.4s]"
", current SyncLevel is too large (%u)",
acpi_ut_get_node_name(method_node),
walk_state->thread->current_sync_level));
return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
}
/*
* Obtain the method mutex if necessary. Do not acquire mutex for a
* recursive call.
*/
if (!walk_state ||
!obj_desc->method.mutex->mutex.thread_id ||
(walk_state->thread->thread_id !=
obj_desc->method.mutex->mutex.thread_id)) {
/*
* Acquire the method mutex. This releases the interpreter if we
* block (and reacquires it before it returns)
*/
status =
acpi_ex_system_wait_mutex(obj_desc->method.mutex->
mutex.os_mutex,
ACPI_WAIT_FOREVER);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Update the mutex and walk info and save the original sync_level */
if (walk_state) {
obj_desc->method.mutex->mutex.
original_sync_level =
walk_state->thread->current_sync_level;
obj_desc->method.mutex->mutex.thread_id =
walk_state->thread->thread_id;
/*
* Update the current sync_level only if this is not an auto-
* serialized method. In the auto case, we have to ignore
* the sync level for the method mutex (created for the
* auto-serialization) because we have no idea of what the
* sync level should be. Therefore, just ignore it.
*/
if (!(obj_desc->method.info_flags &
ACPI_METHOD_IGNORE_SYNC_LEVEL)) {
walk_state->thread->current_sync_level =
obj_desc->method.sync_level;
}
} else {
obj_desc->method.mutex->mutex.
original_sync_level =
obj_desc->method.mutex->mutex.sync_level;
obj_desc->method.mutex->mutex.thread_id =
acpi_os_get_thread_id();
}
}
/* Always increase acquisition depth */
obj_desc->method.mutex->mutex.acquisition_depth++;
}
/*
* Allocate an Owner ID for this method, only if this is the first thread
* to begin concurrent execution. We only need one owner_id, even if the
* method is invoked recursively.
*/
if (!obj_desc->method.owner_id) {
status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
if (ACPI_FAILURE(status)) {
goto cleanup;
}
}
/*
* Increment the method parse tree thread count since it has been
* reentered one more time (even if it is the same thread)
*/
obj_desc->method.thread_count++;
acpi_method_count++;
return_ACPI_STATUS(status);
cleanup:
/* On error, must release the method mutex (if present) */
if (obj_desc->method.mutex) {
acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
}
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_call_control_method
*
* PARAMETERS: thread - Info for this thread
* this_walk_state - Current walk state
* op - Current Op to be walked
*
* RETURN: Status
*
* DESCRIPTION: Transfer execution to a called control method
*
******************************************************************************/
acpi_status
acpi_ds_call_control_method(struct acpi_thread_state *thread,
struct acpi_walk_state *this_walk_state,
union acpi_parse_object *op)
{
acpi_status status;
struct acpi_namespace_node *method_node;
struct acpi_walk_state *next_walk_state = NULL;
union acpi_operand_object *obj_desc;
struct acpi_evaluate_info *info;
u32 i;
ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Calling method %p, currentstate=%p\n",
this_walk_state->prev_op, this_walk_state));
/*
* Get the namespace entry for the control method we are about to call
*/
method_node = this_walk_state->method_call_node;
if (!method_node) {
return_ACPI_STATUS(AE_NULL_ENTRY);
}
obj_desc = acpi_ns_get_attached_object(method_node);
if (!obj_desc) {
return_ACPI_STATUS(AE_NULL_OBJECT);
}
/* Init for new method, possibly wait on method mutex */
status =
acpi_ds_begin_method_execution(method_node, obj_desc,
this_walk_state);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Begin method parse/execution. Create a new walk state */
next_walk_state =
acpi_ds_create_walk_state(obj_desc->method.owner_id, NULL, obj_desc,
thread);
if (!next_walk_state) {
status = AE_NO_MEMORY;
goto cleanup;
}
/*
* The resolved arguments were put on the previous walk state's operand
* stack. Operands on the previous walk state stack always
* start at index 0. Also, null terminate the list of arguments
*/
this_walk_state->operands[this_walk_state->num_operands] = NULL;
/*
* Allocate and initialize the evaluation information block
* TBD: this is somewhat inefficient, should change interface to
* ds_init_aml_walk. For now, keeps this struct off the CPU stack
*/
info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
if (!info) {
status = AE_NO_MEMORY;
goto pop_walk_state;
}
info->parameters = &this_walk_state->operands[0];
status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
obj_desc->method.aml_start,
obj_desc->method.aml_length, info,
ACPI_IMODE_EXECUTE);
ACPI_FREE(info);
if (ACPI_FAILURE(status)) {
goto pop_walk_state;
}
next_walk_state->method_nesting_depth =
this_walk_state->method_nesting_depth + 1;
/*
* Delete the operands on the previous walkstate operand stack
* (they were copied to new objects)
*/
for (i = 0; i < obj_desc->method.param_count; i++) {
acpi_ut_remove_reference(this_walk_state->operands[i]);
this_walk_state->operands[i] = NULL;
}
/* Clear the operand stack */
this_walk_state->num_operands = 0;
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
method_node->name.ascii, next_walk_state));
this_walk_state->method_pathname =
acpi_ns_get_normalized_pathname(method_node, TRUE);
this_walk_state->method_is_nested = TRUE;
/* Optional object evaluation log */
ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
"%-26s: %*s%s\n", " Nested method call",
next_walk_state->method_nesting_depth * 3, " ",
&this_walk_state->method_pathname[1]));
/* Invoke an internal method if necessary */
if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
status =
obj_desc->method.dispatch.implementation(next_walk_state);
if (status == AE_OK) {
status = AE_CTRL_TERMINATE;
}
}
return_ACPI_STATUS(status);
pop_walk_state:
/* On error, pop the walk state to be deleted from thread */
acpi_ds_pop_walk_state(thread);
cleanup:
/* On error, we must terminate the method properly */
acpi_ds_terminate_control_method(obj_desc, next_walk_state);
acpi_ds_delete_walk_state(next_walk_state);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_restart_control_method
*
* PARAMETERS: walk_state - State for preempted method (caller)
* return_desc - Return value from the called method
*
* RETURN: Status
*
* DESCRIPTION: Restart a method that was preempted by another (nested) method
* invocation. Handle the return value (if any) from the callee.
*
******************************************************************************/
acpi_status
acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
union acpi_operand_object *return_desc)
{
acpi_status status;
int same_as_implicit_return;
ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
acpi_ut_get_node_name(walk_state->method_node),
walk_state->method_call_op, return_desc));
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
" ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
walk_state->return_used,
walk_state->results, walk_state));
/* Did the called method return a value? */
if (return_desc) {
/* Is the implicit return object the same as the return desc? */
same_as_implicit_return =
(walk_state->implicit_return_obj == return_desc);
/* Are we actually going to use the return value? */
if (walk_state->return_used) {
/* Save the return value from the previous method */
status = acpi_ds_result_push(return_desc, walk_state);
if (ACPI_FAILURE(status)) {
acpi_ut_remove_reference(return_desc);
return_ACPI_STATUS(status);
}
/*
* Save as THIS method's return value in case it is returned
* immediately to yet another method
*/
walk_state->return_desc = return_desc;
}
/*
* The following code is the optional support for the so-called
* "implicit return". Some AML code assumes that the last value of the
* method is "implicitly" returned to the caller, in the absence of an
* explicit return value.
*
* Just save the last result of the method as the return value.
*
* NOTE: this is optional because the ASL language does not actually
* support this behavior.
*/
else if (!acpi_ds_do_implicit_return
(return_desc, walk_state, FALSE)
|| same_as_implicit_return) {
/*
* Delete the return value if it will not be used by the
* calling method or remove one reference if the explicit return
* is the same as the implicit return value.
*/
acpi_ut_remove_reference(return_desc);
}
}
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_terminate_control_method
*
* PARAMETERS: method_desc - Method object
* walk_state - State associated with the method
*
* RETURN: None
*
* DESCRIPTION: Terminate a control method. Delete everything that the method
* created, delete all locals and arguments, and delete the parse
* tree if requested.
*
* MUTEX: Interpreter is locked
*
******************************************************************************/
void
acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
struct acpi_walk_state *walk_state)
{
ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
/* method_desc is required, walk_state is optional */
if (!method_desc) {
return_VOID;
}
if (walk_state) {
/* Delete all arguments and locals */
acpi_ds_method_data_delete_all(walk_state);
/*
* Delete any namespace objects created anywhere within the
* namespace by the execution of this method. Unless:
* 1) This method is a module-level executable code method, in which
* case we want make the objects permanent.
* 2) There are other threads executing the method, in which case we
* will wait until the last thread has completed.
*/
if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
&& (method_desc->method.thread_count == 1)) {
/* Delete any direct children of (created by) this method */
(void)acpi_ex_exit_interpreter();
acpi_ns_delete_namespace_subtree(walk_state->
method_node);
(void)acpi_ex_enter_interpreter();
/*
* Delete any objects that were created by this method
* elsewhere in the namespace (if any were created).
* Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
* deletion such that we don't have to perform an entire
* namespace walk for every control method execution.
*/
if (method_desc->method.
info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
(void)acpi_ex_exit_interpreter();
acpi_ns_delete_namespace_by_owner(method_desc->
method.
owner_id);
(void)acpi_ex_enter_interpreter();
method_desc->method.info_flags &=
~ACPI_METHOD_MODIFIED_NAMESPACE;
}
}
/*
* If method is serialized, release the mutex and restore the
* current sync level for this thread
*/
if (method_desc->method.mutex) {
/* Acquisition Depth handles recursive calls */
method_desc->method.mutex->mutex.acquisition_depth--;
if (!method_desc->method.mutex->mutex.acquisition_depth) {
walk_state->thread->current_sync_level =
method_desc->method.mutex->mutex.
original_sync_level;
acpi_os_release_mutex(method_desc->method.
mutex->mutex.os_mutex);
method_desc->method.mutex->mutex.thread_id = 0;
}
}
}
/* Decrement the thread count on the method */
if (method_desc->method.thread_count) {
method_desc->method.thread_count--;
} else {
ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
}
/* Are there any other threads currently executing this method? */
if (method_desc->method.thread_count) {
/*
* Additional threads. Do not release the owner_id in this case,
* we immediately reuse it for the next thread executing this method
*/
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"*** Completed execution of one thread, %u threads remaining\n",
method_desc->method.thread_count));
} else {
/* This is the only executing thread for this method */
/*
* Support to dynamically change a method from not_serialized to
* Serialized if it appears that the method is incorrectly written and
* does not support multiple thread execution. The best example of this
* is if such a method creates namespace objects and blocks. A second
* thread will fail with an AE_ALREADY_EXISTS exception.
*
* This code is here because we must wait until the last thread exits
* before marking the method as serialized.
*/
if (method_desc->method.
info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
if (walk_state) {
ACPI_INFO(("Marking method %4.4s as Serialized "
"because of AE_ALREADY_EXISTS error",
walk_state->method_node->name.
ascii));
}
/*
* Method tried to create an object twice and was marked as
* "pending serialized". The probable cause is that the method
* cannot handle reentrancy.
*
* The method was created as not_serialized, but it tried to create
* a named object and then blocked, causing the second thread
* entrance to begin and then fail. Workaround this problem by
* marking the method permanently as Serialized when the last
* thread exits here.
*/
method_desc->method.info_flags &=
~ACPI_METHOD_SERIALIZED_PENDING;
method_desc->method.info_flags |=
(ACPI_METHOD_SERIALIZED |
ACPI_METHOD_IGNORE_SYNC_LEVEL);
method_desc->method.sync_level = 0;
}
/* No more threads, we can free the owner_id */
if (!
(method_desc->method.
info_flags & ACPI_METHOD_MODULE_LEVEL)) {
acpi_ut_release_owner_id(&method_desc->method.owner_id);
}
}
acpi_ex_stop_trace_method((struct acpi_namespace_node *)method_desc->
method.node, method_desc, walk_state);
return_VOID;
}
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