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authorMukesh Ojha <mojha@codeaurora.org>2019-07-31 20:35:03 +0530
committerPeter Zijlstra <peterz@infradead.org>2019-08-06 12:49:16 +0200
commit5f35d5a66b3ec62cb5ec4ec2ad9aebe2ac325673 (patch)
treedf9ea73b10d8939415d4931b8d5ec949fcd463bd /kernel/locking/mutex.c
parent24a376d65177009a4dd8d846543c5dc69f5c4ced (diff)
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/mutex.c')
-rw-r--r--kernel/locking/mutex.c39
1 files changed, 39 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;