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author | Mukesh Ojha <mojha@codeaurora.org> | 2019-07-31 17:05:03 +0200 |
---|---|---|
committer | Peter Zijlstra <peterz@infradead.org> | 2019-08-06 12:49:16 +0200 |
commit | 5f35d5a66b3ec62cb5ec4ec2ad9aebe2ac325673 (patch) | |
tree | df9ea73b10d8939415d4931b8d5ec949fcd463bd /kernel/locking | |
parent | locking/qspinlock,x86: Clarify virt_spin_lock_key (diff) | |
download | linux-5f35d5a66b3ec62cb5ec4ec2ad9aebe2ac325673.tar.xz linux-5f35d5a66b3ec62cb5ec4ec2ad9aebe2ac325673.zip |
locking/mutex: Make __mutex_owner static to mutex.c
__mutex_owner() should only be used by the mutex api's.
So, to put this restiction let's move the __mutex_owner()
function definition from linux/mutex.h to mutex.c file.
There exist functions that uses __mutex_owner() like
mutex_is_locked() and mutex_trylock_recursive(), So
to keep legacy thing intact move them as well and
export them.
Move mutex_waiter structure also to keep it private to the
file.
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: mingo@redhat.com
Cc: will@kernel.org
Link: https://lkml.kernel.org/r/1564585504-3543-1-git-send-email-mojha@codeaurora.org
Diffstat (limited to 'kernel/locking')
-rw-r--r-- | kernel/locking/mutex.c | 39 | ||||
-rw-r--r-- | kernel/locking/mutex.h | 2 |
2 files changed, 41 insertions, 0 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index 5e069734363c..ac4929f1e085 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -36,6 +36,19 @@ # include "mutex.h" #endif +/* + * This is the control structure for tasks blocked on mutex, + * which resides on the blocked task's kernel stack: + */ +struct mutex_waiter { + struct list_head list; + struct task_struct *task; + struct ww_acquire_ctx *ww_ctx; +#ifdef CONFIG_DEBUG_MUTEXES + void *magic; +#endif +}; + void __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) { @@ -65,11 +78,37 @@ EXPORT_SYMBOL(__mutex_init); #define MUTEX_FLAGS 0x07 +/* + * Internal helper function; C doesn't allow us to hide it :/ + * + * DO NOT USE (outside of mutex code). + */ +static inline struct task_struct *__mutex_owner(struct mutex *lock) +{ + return (struct task_struct *)(atomic_long_read(&lock->owner) & ~0x07); +} + static inline struct task_struct *__owner_task(unsigned long owner) { return (struct task_struct *)(owner & ~MUTEX_FLAGS); } +bool mutex_is_locked(struct mutex *lock) +{ + return __mutex_owner(lock) != NULL; +} +EXPORT_SYMBOL(mutex_is_locked); + +__must_check enum mutex_trylock_recursive_enum +mutex_trylock_recursive(struct mutex *lock) +{ + if (unlikely(__mutex_owner(lock) == current)) + return MUTEX_TRYLOCK_RECURSIVE; + + return mutex_trylock(lock); +} +EXPORT_SYMBOL(mutex_trylock_recursive); + static inline unsigned long __owner_flags(unsigned long owner) { return owner & MUTEX_FLAGS; diff --git a/kernel/locking/mutex.h b/kernel/locking/mutex.h index 1c2287d3fa71..7cde5c6d414e 100644 --- a/kernel/locking/mutex.h +++ b/kernel/locking/mutex.h @@ -19,6 +19,8 @@ #define debug_mutex_unlock(lock) do { } while (0) #define debug_mutex_init(lock, name, key) do { } while (0) +struct mutex_waiter; + static inline void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) { |