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>

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 6ec42252e46eb9becd2f278ec5f760650714ef78..3dba2cf50241d877906dd922dd88351f15f7fee4 100644 (file)
--- 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 7832e5008959e6ef27ea2f4f79a63737a6ed10ce..eb7b414d232bed6d1df090255c4ee266cf27010d 100644 (file)
--- 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 <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. */