From 77584ee57434813b50fc85cde995a6271a5081b7 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 23 Dec 2014 16:40:17 +1100 Subject: [PATCH] hwrng: core - Use struct completion for cleanup_done There is no point in doing a manual completion for cleanup_done when struct completion fits in perfectly. Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 12 +++--------- include/linux/hw_random.h | 3 ++- 2 files changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 6ec42252e46e..3dba2cf50241 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -60,7 +60,6 @@ static DEFINE_MUTEX(rng_mutex); static DEFINE_MUTEX(reading_mutex); static int data_avail; static u8 *rng_buffer, *rng_fillbuf; -static DECLARE_WAIT_QUEUE_HEAD(rng_done); static unsigned short current_quality; static unsigned short default_quality; /* = 0; default to "off" */ @@ -100,10 +99,7 @@ static inline void cleanup_rng(struct kref *kref) if (rng->cleanup) rng->cleanup(rng); - /* cleanup_done should be updated after cleanup finishes */ - smp_wmb(); - rng->cleanup_done = true; - wake_up_all(&rng_done); + complete(&rng->cleanup_done); } static void set_current_rng(struct hwrng *rng) @@ -498,7 +494,7 @@ int hwrng_register(struct hwrng *rng) add_early_randomness(rng); } - rng->cleanup_done = false; + init_completion(&rng->cleanup_done); out_unlock: mutex_unlock(&rng_mutex); @@ -532,9 +528,7 @@ void hwrng_unregister(struct hwrng *rng) } else mutex_unlock(&rng_mutex); - /* Just in case rng is reading right now, wait. */ - wait_event(rng_done, rng->cleanup_done && - atomic_read(&rng->ref.refcount) == 0); + wait_for_completion(&rng->cleanup_done); } EXPORT_SYMBOL_GPL(hwrng_unregister); diff --git a/include/linux/hw_random.h b/include/linux/hw_random.h index 7832e5008959..eb7b414d232b 100644 --- a/include/linux/hw_random.h +++ b/include/linux/hw_random.h @@ -12,6 +12,7 @@ #ifndef LINUX_HWRANDOM_H_ #define LINUX_HWRANDOM_H_ +#include #include #include #include @@ -46,7 +47,7 @@ struct hwrng { /* internal. */ struct list_head list; struct kref ref; - bool cleanup_done; + struct completion cleanup_done; }; /** Register a new Hardware Random Number Generator driver. */ -- 2.20.1