Ingo Molnar | 6053ee3 | 2006-01-09 15:59:19 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Mutexes: blocking mutual exclusion locks |
| 3 | * |
| 4 | * started by Ingo Molnar: |
| 5 | * |
| 6 | * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> |
| 7 | * |
| 8 | * This file contains mutex debugging related internal prototypes, for the |
| 9 | * !CONFIG_DEBUG_MUTEXES case. Most of them are NOPs: |
| 10 | */ |
| 11 | |
Ingo Molnar | 1fb00c6 | 2006-06-26 00:24:31 -0700 | [diff] [blame] | 12 | #define spin_lock_mutex(lock, flags) \ |
| 13 | do { spin_lock(lock); (void)(flags); } while (0) |
| 14 | #define spin_unlock_mutex(lock, flags) \ |
| 15 | do { spin_unlock(lock); (void)(flags); } while (0) |
Linus Torvalds | 6720a30 | 2016-06-23 12:11:17 -0700 | [diff] [blame] | 16 | #define mutex_remove_waiter(lock, waiter, task) \ |
Ingo Molnar | 6053ee3 | 2006-01-09 15:59:19 -0800 | [diff] [blame] | 17 | __list_del((waiter)->list.prev, (waiter)->list.next) |
| 18 | |
Davidlohr Bueso | 7608a43 | 2014-07-30 13:41:54 -0700 | [diff] [blame] | 19 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
Jason Low | 6e28147 | 2016-05-20 15:19:36 -0700 | [diff] [blame] | 20 | /* |
| 21 | * The mutex owner can get read and written to locklessly. |
| 22 | * We should use WRITE_ONCE when writing the owner value to |
| 23 | * avoid store tearing, otherwise, a thread could potentially |
| 24 | * read a partially written and incomplete owner value. |
| 25 | */ |
Peter Zijlstra | 0d66bf6 | 2009-01-12 14:01:47 +0100 | [diff] [blame] | 26 | static inline void mutex_set_owner(struct mutex *lock) |
| 27 | { |
Jason Low | 6e28147 | 2016-05-20 15:19:36 -0700 | [diff] [blame] | 28 | WRITE_ONCE(lock->owner, current); |
Peter Zijlstra | 0d66bf6 | 2009-01-12 14:01:47 +0100 | [diff] [blame] | 29 | } |
| 30 | |
| 31 | static inline void mutex_clear_owner(struct mutex *lock) |
| 32 | { |
Jason Low | 6e28147 | 2016-05-20 15:19:36 -0700 | [diff] [blame] | 33 | WRITE_ONCE(lock->owner, NULL); |
Peter Zijlstra | 0d66bf6 | 2009-01-12 14:01:47 +0100 | [diff] [blame] | 34 | } |
| 35 | #else |
| 36 | static inline void mutex_set_owner(struct mutex *lock) |
| 37 | { |
| 38 | } |
| 39 | |
| 40 | static inline void mutex_clear_owner(struct mutex *lock) |
| 41 | { |
| 42 | } |
| 43 | #endif |
| 44 | |
Ingo Molnar | 6053ee3 | 2006-01-09 15:59:19 -0800 | [diff] [blame] | 45 | #define debug_mutex_wake_waiter(lock, waiter) do { } while (0) |
| 46 | #define debug_mutex_free_waiter(waiter) do { } while (0) |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 47 | #define debug_mutex_add_waiter(lock, waiter, ti) do { } while (0) |
Ingo Molnar | 6053ee3 | 2006-01-09 15:59:19 -0800 | [diff] [blame] | 48 | #define debug_mutex_unlock(lock) do { } while (0) |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 49 | #define debug_mutex_init(lock, name, key) do { } while (0) |
Ingo Molnar | 6053ee3 | 2006-01-09 15:59:19 -0800 | [diff] [blame] | 50 | |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 51 | static inline void |
| 52 | debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) |
| 53 | { |
| 54 | } |