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 <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2014-12-23 16:40:17 +11:00
parent d69e75deff
commit 77584ee574
2 changed files with 5 additions and 10 deletions

View File

@ -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);

View File

@ -12,6 +12,7 @@
#ifndef LINUX_HWRANDOM_H_
#define LINUX_HWRANDOM_H_
#include <linux/completion.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/kref.h>
@ -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. */