locking/atomic, kref: Kill kref_sub()

By general sentiment kref_sub() is a bad interface, make it go away.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 5 insertions, 42 deletions

diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 652e45be97c8..9a465314572c 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -332,19 +332,6 @@ extern int ttm_bo_validate(struct ttm_buffer_object *bo,
  */
 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
 
-
-/**
- * ttm_bo_list_ref_sub
- *
- * @bo: The buffer object.
- * @count: The number of references with which to decrease @bo::list_kref;
- * @never_free: The refcount should not reach zero with this operation.
- *
- * Release @count lru list references to this buffer object.
- */
-extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
-				bool never_free);
-
 /**
  * ttm_bo_add_to_lru
  *
@@ -367,7 +354,7 @@ extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
  * and is usually called just immediately after the bo has been reserved to
  * avoid recursive reservation from lru lists.
  */
-extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
+extern void ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
 
 /**
  * ttm_bo_move_to_lru_tail
diff --git a/include/linux/kref.h b/include/linux/kref.h
index 7c88d865f82f..31c49a64cdf9 100644
--- a/include/linux/kref.h
+++ b/include/linux/kref.h
@@ -54,9 +54,8 @@ static inline void kref_get(struct kref *kref)
 }
 
 /**
- * kref_sub - subtract a number of refcounts for object.
+ * kref_put - decrement refcount for object.
  * @kref: object.
- * @count: Number of recounts to subtract.
  * @release: pointer to the function that will clean up the object when the
  *	     last reference to the object is released.
  *	     This pointer is required, and it is not acceptable to pass kfree
@@ -65,46 +64,23 @@ static inline void kref_get(struct kref *kref)
  *	     maintainer, and anyone else who happens to notice it.  You have
  *	     been warned.
  *
- * Subtract @count from the refcount, and if 0, call release().
+ * Decrement the refcount, and if 0, call release().
  * Return 1 if the object was removed, otherwise return 0.  Beware, if this
  * function returns 0, you still can not count on the kref from remaining in
  * memory.  Only use the return value if you want to see if the kref is now
  * gone, not present.
  */
-static inline int kref_sub(struct kref *kref, unsigned int count,
-	     void (*release)(struct kref *kref))
+static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref))
 {
 	WARN_ON(release == NULL);
 
-	if (atomic_sub_and_test((int) count, &kref->refcount)) {
+	if (atomic_dec_and_test(&kref->refcount)) {
 		release(kref);
 		return 1;
 	}
 	return 0;
 }
 
-/**
- * kref_put - decrement refcount for object.
- * @kref: object.
- * @release: pointer to the function that will clean up the object when the
- *	     last reference to the object is released.
- *	     This pointer is required, and it is not acceptable to pass kfree
- *	     in as this function.  If the caller does pass kfree to this
- *	     function, you will be publicly mocked mercilessly by the kref
- *	     maintainer, and anyone else who happens to notice it.  You have
- *	     been warned.
- *
- * Decrement the refcount, and if 0, call release().
- * Return 1 if the object was removed, otherwise return 0.  Beware, if this
- * function returns 0, you still can not count on the kref from remaining in
- * memory.  Only use the return value if you want to see if the kref is now
- * gone, not present.
- */
-static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref))
-{
-	return kref_sub(kref, 1, release);
-}
-
 static inline int kref_put_mutex(struct kref *kref,
 				 void (*release)(struct kref *kref),
 				 struct mutex *lock)