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authorRodrigo Vivi <[email protected]>2018-07-23 09:13:12 -0700
committerRodrigo Vivi <[email protected]>2018-07-23 09:13:12 -0700
commitc74a7469f97c0f40b46e82ee979f9fb1bb6e847c (patch)
treef2690a1a916b73ef94657fbf0e0141ae57701825 /include/linux/spinlock.h
parent6f15a7de86c8cf2dc09fc9e6d07047efa40ef809 (diff)
parent500775074f88d9cf5416bed2ca19592812d62c41 (diff)
Merge drm/drm-next into drm-intel-next-queued
We need a backmerge to get DP_DPCD_REV_14 before we push other i915 changes to dinq that could break compilation. Signed-off-by: Rodrigo Vivi <[email protected]>
Diffstat (limited to 'include/linux/spinlock.h')
-rw-r--r--include/linux/spinlock.h23
1 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 4894d322d258..fd57888d4942 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -380,6 +380,24 @@ static __always_inline int spin_trylock_irq(spinlock_t *lock)
raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
})
+/**
+ * spin_is_locked() - Check whether a spinlock is locked.
+ * @lock: Pointer to the spinlock.
+ *
+ * This function is NOT required to provide any memory ordering
+ * guarantees; it could be used for debugging purposes or, when
+ * additional synchronization is needed, accompanied with other
+ * constructs (memory barriers) enforcing the synchronization.
+ *
+ * Returns: 1 if @lock is locked, 0 otherwise.
+ *
+ * Note that the function only tells you that the spinlock is
+ * seen to be locked, not that it is locked on your CPU.
+ *
+ * Further, on CONFIG_SMP=n builds with CONFIG_DEBUG_SPINLOCK=n,
+ * the return value is always 0 (see include/linux/spinlock_up.h).
+ * Therefore you should not rely heavily on the return value.
+ */
static __always_inline int spin_is_locked(spinlock_t *lock)
{
return raw_spin_is_locked(&lock->rlock);
@@ -409,6 +427,11 @@ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
#define atomic_dec_and_lock(atomic, lock) \
__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
+extern int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock,
+ unsigned long *flags);
+#define atomic_dec_and_lock_irqsave(atomic, lock, flags) \
+ __cond_lock(lock, _atomic_dec_and_lock_irqsave(atomic, lock, &(flags)))
+
int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *lock_mask,
size_t max_size, unsigned int cpu_mult,
gfp_t gfp);