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authorMaarten Lankhorst <maarten.lankhorst@canonical.com>2013-06-20 13:31:05 +0200
committerIngo Molnar <mingo@kernel.org>2013-06-26 12:10:55 +0200
commita41b56efa70e060f650aeb54740aaf52044a1ead (patch)
tree776921423ea47eeeb4451aa9f66c49535bf64048 /include/asm-generic
parent1e876e3b1a9df25bb04682b0d48aaa7e8ae1fc82 (diff)
downloadtalos-op-linux-a41b56efa70e060f650aeb54740aaf52044a1ead.tar.gz
talos-op-linux-a41b56efa70e060f650aeb54740aaf52044a1ead.zip
arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
This will allow me to call functions that have multiple arguments if fastpath fails. This is required to support ticket mutexes, because they need to be able to pass an extra argument to the fail function. Originally I duplicated the functions, by adding __mutex_fastpath_lock_retval_arg. This ended up being just a duplication of the existing function, so a way to test if fastpath was called ended up being better. This also cleaned up the reservation mutex patch some by being able to call an atomic_set instead of atomic_xchg, and making it easier to detect if the wrong unlock function was previously used. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: robclark@gmail.com Cc: rostedt@goodmis.org Cc: daniel@ffwll.ch Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20130620113105.4001.83929.stgit@patser Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/mutex-dec.h10
-rw-r--r--include/asm-generic/mutex-null.h2
-rw-r--r--include/asm-generic/mutex-xchg.h10
3 files changed, 9 insertions, 13 deletions
diff --git a/include/asm-generic/mutex-dec.h b/include/asm-generic/mutex-dec.h
index f104af7cf437..d4f9fb4e53df 100644
--- a/include/asm-generic/mutex-dec.h
+++ b/include/asm-generic/mutex-dec.h
@@ -28,17 +28,15 @@ __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
* __mutex_fastpath_lock_retval - try to take the lock by moving the count
* from 1 to a 0 value
* @count: pointer of type atomic_t
- * @fail_fn: function to call if the original value was not 1
*
- * Change the count from 1 to a value lower than 1, and call <fail_fn> if
- * it wasn't 1 originally. This function returns 0 if the fastpath succeeds,
- * or anything the slow path function returns.
+ * Change the count from 1 to a value lower than 1. This function returns 0
+ * if the fastpath succeeds, or -1 otherwise.
*/
static inline int
-__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
+__mutex_fastpath_lock_retval(atomic_t *count)
{
if (unlikely(atomic_dec_return(count) < 0))
- return fail_fn(count);
+ return -1;
return 0;
}
diff --git a/include/asm-generic/mutex-null.h b/include/asm-generic/mutex-null.h
index e1bbbc72b6a2..61069ed334e2 100644
--- a/include/asm-generic/mutex-null.h
+++ b/include/asm-generic/mutex-null.h
@@ -11,7 +11,7 @@
#define _ASM_GENERIC_MUTEX_NULL_H
#define __mutex_fastpath_lock(count, fail_fn) fail_fn(count)
-#define __mutex_fastpath_lock_retval(count, fail_fn) fail_fn(count)
+#define __mutex_fastpath_lock_retval(count) (-1)
#define __mutex_fastpath_unlock(count, fail_fn) fail_fn(count)
#define __mutex_fastpath_trylock(count, fail_fn) fail_fn(count)
#define __mutex_slowpath_needs_to_unlock() 1
diff --git a/include/asm-generic/mutex-xchg.h b/include/asm-generic/mutex-xchg.h
index c04e0db8a2d6..f169ec064785 100644
--- a/include/asm-generic/mutex-xchg.h
+++ b/include/asm-generic/mutex-xchg.h
@@ -39,18 +39,16 @@ __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
* __mutex_fastpath_lock_retval - try to take the lock by moving the count
* from 1 to a 0 value
* @count: pointer of type atomic_t
- * @fail_fn: function to call if the original value was not 1
*
- * Change the count from 1 to a value lower than 1, and call <fail_fn> if it
- * wasn't 1 originally. This function returns 0 if the fastpath succeeds,
- * or anything the slow path function returns
+ * Change the count from 1 to a value lower than 1. This function returns 0
+ * if the fastpath succeeds, or -1 otherwise.
*/
static inline int
-__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
+__mutex_fastpath_lock_retval(atomic_t *count)
{
if (unlikely(atomic_xchg(count, 0) != 1))
if (likely(atomic_xchg(count, -1) != 1))
- return fail_fn(count);
+ return -1;
return 0;
}
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