cregit-Linux how code gets into the kernel

Release 4.11 drivers/acpi/acpica/exmutex.c

/******************************************************************************
 *
 * Module Name: exmutex - ASL Mutex Acquire/Release functions
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2017, Intel Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"
#include "acevents.h"


#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exmutex")

/* Local prototypes */
static void
acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
		   struct acpi_thread_state *thread);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_unlink_mutex
 *
 * PARAMETERS:  obj_desc            - The mutex to be unlinked
 *
 * RETURN:      None
 *
 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
 *
 ******************************************************************************/


void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc) { struct acpi_thread_state *thread = obj_desc->mutex.owner_thread; if (!thread) { return; } /* Doubly linked list */ if (obj_desc->mutex.next) { (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev; } if (obj_desc->mutex.prev) { (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next; /* * Migrate the previous sync level associated with this mutex to * the previous mutex on the list so that it may be preserved. * This handles the case where several mutexes have been acquired * at the same level, but are not released in opposite order. */ (obj_desc->mutex.prev)->mutex.original_sync_level = obj_desc->mutex.original_sync_level; } else { thread->acquired_mutex_list = obj_desc->mutex.next; } }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds6252.54%220.00%
Andy Grover2622.03%330.00%
Robert Moore1916.10%220.00%
Len Brown119.32%330.00%
Total118100.00%10100.00%

/******************************************************************************* * * FUNCTION: acpi_ex_link_mutex * * PARAMETERS: obj_desc - The mutex to be linked * thread - Current executing thread object * * RETURN: None * * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk * ******************************************************************************/
static void acpi_ex_link_mutex(union acpi_operand_object *obj_desc, struct acpi_thread_state *thread) { union acpi_operand_object *list_head; list_head = thread->acquired_mutex_list; /* This object will be the first object in the list */ obj_desc->mutex.prev = NULL; obj_desc->mutex.next = list_head; /* Update old first object to point back to this object */ if (list_head) { list_head->mutex.prev = obj_desc; } /* Update list head */ thread->acquired_mutex_list = obj_desc; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds4771.21%233.33%
Andy Grover1827.27%350.00%
Robert Moore11.52%116.67%
Total66100.00%6100.00%

/******************************************************************************* * * FUNCTION: acpi_ex_acquire_mutex_object * * PARAMETERS: timeout - Timeout in milliseconds * obj_desc - Mutex object * thread_id - Current thread state * * RETURN: Status * * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common * path that supports multiple acquires by the same thread. * * MUTEX: Interpreter must be locked * * NOTE: This interface is called from three places: * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the * global lock * 3) From the external interface, acpi_acquire_global_lock * ******************************************************************************/
acpi_status acpi_ex_acquire_mutex_object(u16 timeout, union acpi_operand_object *obj_desc, acpi_thread_id thread_id) { acpi_status status; ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc); if (!obj_desc) { return_ACPI_STATUS(AE_BAD_PARAMETER); } /* Support for multiple acquires by the owning thread */ if (obj_desc->mutex.thread_id == thread_id) { /* * The mutex is already owned by this thread, just increment the * acquisition depth */ obj_desc->mutex.acquisition_depth++; return_ACPI_STATUS(AE_OK); } /* Acquire the mutex, wait if necessary. Special case for Global Lock */ if (obj_desc == acpi_gbl_global_lock_mutex) { status = acpi_ev_acquire_global_lock(timeout); } else { status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex, timeout); } if (ACPI_FAILURE(status)) { /* Includes failure from a timeout on time_desc */ return_ACPI_STATUS(status); } /* Acquired the mutex: update mutex object */ obj_desc->mutex.thread_id = thread_id; obj_desc->mutex.acquisition_depth = 1; obj_desc->mutex.original_sync_level = 0; obj_desc->mutex.owner_thread = NULL; /* Used only for AML Acquire() */ return_ACPI_STATUS(AE_OK); }

Contributors

PersonTokensPropCommitsCommitProp
Robert Moore150100.00%3100.00%
Total150100.00%3100.00%

/******************************************************************************* * * FUNCTION: acpi_ex_acquire_mutex * * PARAMETERS: time_desc - Timeout integer * obj_desc - Mutex object * walk_state - Current method execution state * * RETURN: Status * * DESCRIPTION: Acquire an AML mutex * ******************************************************************************/
acpi_status acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, union acpi_operand_object *obj_desc, struct acpi_walk_state *walk_state) { acpi_status status; ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc); if (!obj_desc) { return_ACPI_STATUS(AE_BAD_PARAMETER); } /* Must have a valid thread state struct */ if (!walk_state->thread) { ACPI_ERROR((AE_INFO, "Cannot acquire Mutex [%4.4s], null thread info", acpi_ut_get_node_name(obj_desc->mutex.node))); return_ACPI_STATUS(AE_AML_INTERNAL); } /* * Current sync level must be less than or equal to the sync level * of the mutex. This mechanism provides some deadlock prevention. */ if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) { ACPI_ERROR((AE_INFO, "Cannot acquire Mutex [%4.4s], " "current SyncLevel is too large (%u)", acpi_ut_get_node_name(obj_desc->mutex.node), walk_state->thread->current_sync_level)); return_ACPI_STATUS(AE_AML_MUTEX_ORDER); } ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Acquiring: Mutex SyncLevel %u, Thread SyncLevel %u, " "Depth %u TID %p\n", obj_desc->mutex.sync_level, walk_state->thread->current_sync_level, obj_desc->mutex.acquisition_depth, walk_state->thread)); status = acpi_ex_acquire_mutex_object((u16)time_desc->integer.value, obj_desc, walk_state->thread->thread_id); if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) { /* Save Thread object, original/current sync levels */ obj_desc->mutex.owner_thread = walk_state->thread; obj_desc->mutex.original_sync_level = walk_state->thread->current_sync_level; walk_state->thread->current_sync_level = obj_desc->mutex.sync_level; /* Link the mutex to the current thread for force-unlock at method exit */ acpi_ex_link_mutex(obj_desc, walk_state->thread); } ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Acquired: Mutex SyncLevel %u, Thread SyncLevel %u, Depth %u\n", obj_desc->mutex.sync_level, walk_state->thread->current_sync_level, obj_desc->mutex.acquisition_depth)); return_ACPI_STATUS(status); }

Contributors

PersonTokensPropCommitsCommitProp
Robert Moore10438.52%850.00%
Linus Torvalds10237.78%212.50%
Andy Grover4617.04%318.75%
Len Brown186.67%318.75%
Total270100.00%16100.00%

/******************************************************************************* * * FUNCTION: acpi_ex_release_mutex_object * * PARAMETERS: obj_desc - The object descriptor for this op * * RETURN: Status * * DESCRIPTION: Release a previously acquired Mutex, low level interface. * Provides a common path that supports multiple releases (after * previous multiple acquires) by the same thread. * * MUTEX: Interpreter must be locked * * NOTE: This interface is called from three places: * 1) From acpi_ex_release_mutex, via an AML Acquire() operator * 2) From acpi_ex_release_global_lock when an AML Field access requires the * global lock * 3) From the external interface, acpi_release_global_lock * ******************************************************************************/
acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc) { acpi_status status = AE_OK; ACPI_FUNCTION_TRACE(ex_release_mutex_object); if (obj_desc->mutex.acquisition_depth == 0) { return_ACPI_STATUS(AE_NOT_ACQUIRED); } /* Match multiple Acquires with multiple Releases */ obj_desc->mutex.acquisition_depth--; if (obj_desc->mutex.acquisition_depth != 0) { /* Just decrement the depth and return */ return_ACPI_STATUS(AE_OK); } if (obj_desc->mutex.owner_thread) { /* Unlink the mutex from the owner's list */ acpi_ex_unlink_mutex(obj_desc); obj_desc->mutex.owner_thread = NULL; } /* Release the mutex, special case for Global Lock */ if (obj_desc == acpi_gbl_global_lock_mutex) { status = acpi_ev_release_global_lock(); } else { acpi_os_release_mutex(obj_desc->mutex.os_mutex); } /* Clear mutex info */ obj_desc->mutex.thread_id = 0; return_ACPI_STATUS(status); }

Contributors

PersonTokensPropCommitsCommitProp
Robert Moore8566.93%538.46%
Linus Torvalds3124.41%215.38%
Andy Grover75.51%323.08%
Len Brown32.36%215.38%
Lin Ming10.79%17.69%
Total127100.00%13100.00%

/******************************************************************************* * * FUNCTION: acpi_ex_release_mutex * * PARAMETERS: obj_desc - The object descriptor for this op * walk_state - Current method execution state * * RETURN: Status * * DESCRIPTION: Release a previously acquired Mutex. * ******************************************************************************/
acpi_status acpi_ex_release_mutex(union acpi_operand_object *obj_desc, struct acpi_walk_state *walk_state) { u8 previous_sync_level; struct acpi_thread_state *owner_thread; acpi_status status = AE_OK; ACPI_FUNCTION_TRACE(ex_release_mutex); if (!obj_desc) { return_ACPI_STATUS(AE_BAD_PARAMETER); } owner_thread = obj_desc->mutex.owner_thread; /* The mutex must have been previously acquired in order to release it */ if (!owner_thread) { ACPI_ERROR((AE_INFO, "Cannot release Mutex [%4.4s], not acquired", acpi_ut_get_node_name(obj_desc->mutex.node))); return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED); } /* Must have a valid thread ID */ if (!walk_state->thread) { ACPI_ERROR((AE_INFO, "Cannot release Mutex [%4.4s], null thread info", acpi_ut_get_node_name(obj_desc->mutex.node))); return_ACPI_STATUS(AE_AML_INTERNAL); } /* * The Mutex is owned, but this thread must be the owner. * Special case for Global Lock, any thread can release */ if ((owner_thread->thread_id != walk_state->thread->thread_id) && (obj_desc != acpi_gbl_global_lock_mutex)) { ACPI_ERROR((AE_INFO, "Thread %u cannot release Mutex [%4.4s] acquired by thread %u", (u32)walk_state->thread->thread_id, acpi_ut_get_node_name(obj_desc->mutex.node), (u32)owner_thread->thread_id)); return_ACPI_STATUS(AE_AML_NOT_OWNER); } /* * The sync level of the mutex must be equal to the current sync level. In * other words, the current level means that at least one mutex at that * level is currently being held. Attempting to release a mutex of a * different level can only mean that the mutex ordering rule is being * violated. This behavior is clarified in ACPI 4.0 specification. */ if (obj_desc->mutex.sync_level != owner_thread->current_sync_level) { ACPI_ERROR((AE_INFO, "Cannot release Mutex [%4.4s], SyncLevel mismatch: " "mutex %u current %u", acpi_ut_get_node_name(obj_desc->mutex.node), obj_desc->mutex.sync_level, walk_state->thread->current_sync_level)); return_ACPI_STATUS(AE_AML_MUTEX_ORDER); } /* * Get the previous sync_level from the head of the acquired mutex list. * This handles the case where several mutexes at the same level have been * acquired, but are not released in reverse order. */ previous_sync_level = owner_thread->acquired_mutex_list->mutex.original_sync_level; ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Releasing: Object SyncLevel %u, Thread SyncLevel %u, " "Prev SyncLevel %u, Depth %u TID %p\n", obj_desc->mutex.sync_level, walk_state->thread->current_sync_level, previous_sync_level, obj_desc->mutex.acquisition_depth, walk_state->thread)); status = acpi_ex_release_mutex_object(obj_desc); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); } if (obj_desc->mutex.acquisition_depth == 0) { /* Restore the previous sync_level */ owner_thread->current_sync_level = previous_sync_level; } ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Released: Object SyncLevel %u, Thread SyncLevel, %u, " "Prev SyncLevel %u, Depth %u\n", obj_desc->mutex.sync_level, walk_state->thread->current_sync_level, previous_sync_level, obj_desc->mutex.acquisition_depth)); return_ACPI_STATUS(status); }

Contributors

PersonTokensPropCommitsCommitProp
Robert Moore18853.71%738.89%
Andy Grover4613.14%211.11%
Linus Torvalds4011.43%211.11%
Dan Carpenter329.14%15.56%
Lin Ming236.57%211.11%
Len Brown205.71%316.67%
Lv Zheng10.29%15.56%
Total350100.00%18100.00%

/******************************************************************************* * * FUNCTION: acpi_ex_release_all_mutexes * * PARAMETERS: thread - Current executing thread object * * RETURN: Status * * DESCRIPTION: Release all mutexes held by this thread * * NOTE: This function is called as the thread is exiting the interpreter. * Mutexes are not released when an individual control method is exited, but * only when the parent thread actually exits the interpreter. This allows one * method to acquire a mutex, and a different method to release it, as long as * this is performed underneath a single parent control method. * ******************************************************************************/
void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread) { union acpi_operand_object *next = thread->acquired_mutex_list; union acpi_operand_object *obj_desc; ACPI_FUNCTION_TRACE(ex_release_all_mutexes); /* Traverse the list of owned mutexes, releasing each one */ while (next) { obj_desc = next; ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Mutex [%4.4s] force-release, SyncLevel %u Depth %u\n", obj_desc->mutex.node->name.ascii, obj_desc->mutex.sync_level, obj_desc->mutex.acquisition_depth)); /* Release the mutex, special case for Global Lock */ if (obj_desc == acpi_gbl_global_lock_mutex) { /* Ignore errors */ (void)acpi_ev_release_global_lock(); } else { acpi_os_release_mutex(obj_desc->mutex.os_mutex); } /* Update Thread sync_level (Last mutex is the important one) */ thread->current_sync_level = obj_desc->mutex.original_sync_level; /* Mark mutex unowned */ next = obj_desc->mutex.next; obj_desc->mutex.prev = NULL; obj_desc->mutex.next = NULL; obj_desc->mutex.acquisition_depth = 0; obj_desc->mutex.owner_thread = NULL; obj_desc->mutex.thread_id = 0; } return_VOID; }

Contributors

PersonTokensPropCommitsCommitProp
Robert Moore10062.11%428.57%
Linus Torvalds3219.88%214.29%
Andy Grover1911.80%428.57%
Len Brown95.59%321.43%
Lin Ming10.62%17.14%
Total161100.00%14100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Robert Moore67552.45%1748.57%
Linus Torvalds32525.25%25.71%
Andy Grover16412.74%514.29%
Len Brown644.97%617.14%
Dan Carpenter322.49%12.86%
Lin Ming251.94%25.71%
Lv Zheng10.08%12.86%
Patrick Mochel10.08%12.86%
Total1287100.00%35100.00%
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