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author | Thomas Gleixner <tglx@linutronix.de> | 2018-07-12 22:19:58 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2018-07-12 22:19:58 +0200 |
commit | c6bb11147eb09bd39f316c6062455b88c905ab6e (patch) | |
tree | 5a1a6ec2970daef5fa8546741ced3ef3924bf807 /lib/refcount.c | |
parent | a8802d97e73346bc81609df9dfba7d3306f40d87 (diff) | |
parent | b061c7a513afe14a68af41cec7c3476befc40e95 (diff) | |
download | linux-c6bb11147eb09bd39f316c6062455b88c905ab6e.tar.bz2 |
Merge branch 'fortglx/4.19/time' of https://git.linaro.org/people/john.stultz/linux into timers/core
Pull timekeeping updates from John Stultz:
- Make the timekeeping update more precise when NTP frequency is set
directly by updating the multiplier.
- Adjust selftests
Diffstat (limited to 'lib/refcount.c')
-rw-r--r-- | lib/refcount.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/refcount.c b/lib/refcount.c index 0eb48353abe3..d3b81cefce91 100644 --- a/lib/refcount.c +++ b/lib/refcount.c @@ -350,3 +350,31 @@ bool refcount_dec_and_lock(refcount_t *r, spinlock_t *lock) } EXPORT_SYMBOL(refcount_dec_and_lock); +/** + * refcount_dec_and_lock_irqsave - return holding spinlock with disabled + * interrupts if able to decrement refcount to 0 + * @r: the refcount + * @lock: the spinlock to be locked + * @flags: saved IRQ-flags if the is acquired + * + * Same as refcount_dec_and_lock() above except that the spinlock is acquired + * with disabled interupts. + * + * Return: true and hold spinlock if able to decrement refcount to 0, false + * otherwise + */ +bool refcount_dec_and_lock_irqsave(refcount_t *r, spinlock_t *lock, + unsigned long *flags) +{ + if (refcount_dec_not_one(r)) + return false; + + spin_lock_irqsave(lock, *flags); + if (!refcount_dec_and_test(r)) { + spin_unlock_irqrestore(lock, *flags); + return false; + } + + return true; +} +EXPORT_SYMBOL(refcount_dec_and_lock_irqsave); |