[PATCH 1/2] percpu: Add __this_cpu_try_cmpxchg()

[Uros Bizjak]

Add __this_cpu_try_cmpxchg() version of the percpu op.

Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Uladzislau Rezki <urezki@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
---
 include/linux/percpu-defs.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index ec3573119923..8efce7414fad 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -475,6 +475,12 @@ do {									\
 	raw_cpu_cmpxchg(pcp, oval, nval);				\
 })
 
+#define __this_cpu_try_cmpxchg(pcp, ovalp, nval)			\
+({									\
+	__this_cpu_preempt_check("try_cmpxchg");			\
+	raw_cpu_try_cmpxchg(pcp, ovalp, nval);				\
+})
+
 #define __this_cpu_sub(pcp, val)	__this_cpu_add(pcp, -(typeof(pcp))(val))
 #define __this_cpu_inc(pcp)		__this_cpu_add(pcp, 1)
 #define __this_cpu_dec(pcp)		__this_cpu_sub(pcp, 1)
-- 
2.45.1