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authorTakashi Iwai <tiwai@suse.de>2014-11-17 22:16:03 +0100
committerTakashi Iwai <tiwai@suse.de>2014-11-17 22:16:03 +0100
commit39ae97ea4b773be81bae9eec08ed1e5c53606c1a (patch)
tree4d55635fb46a86b970c1491cc529eb2770bf3076 /include/linux/rcupdate.h
parenta358a0ef861dae6f8330fb034aaa43adae71ebc1 (diff)
parentcf9a7f7823c67243da44da2ac47ca944a3108282 (diff)
Merge tag 'asoc-v3.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v3.18 As well as the usual driver fixes there's a few other things here: One is a fix for a race in DPCM which is unfortuantely a rather large diffstat, this is the result of growing usage of the mainline code and hence more detailed testing so I'm relatively happy. The other is a fix for non-DT machine driver matching following some of the componentization work which is much more focused. Both have had a while to cook in -next.
Diffstat (limited to 'include/linux/rcupdate.h')
-rw-r--r--include/linux/rcupdate.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index a4a819ffb2d1..53ff1a752d7e 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -617,6 +617,21 @@ static inline void rcu_preempt_sleep_check(void)
#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
/**
+ * lockless_dereference() - safely load a pointer for later dereference
+ * @p: The pointer to load
+ *
+ * Similar to rcu_dereference(), but for situations where the pointed-to
+ * object's lifetime is managed by something other than RCU. That
+ * "something other" might be reference counting or simple immortality.
+ */
+#define lockless_dereference(p) \
+({ \
+ typeof(p) _________p1 = ACCESS_ONCE(p); \
+ smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
+ (_________p1); \
+})
+
+/**
* rcu_assign_pointer() - assign to RCU-protected pointer
* @p: pointer to assign to
* @v: value to assign (publish)