Flush snapdragon instruction cache

Question

I'm currently writing in-kernel hooker code on snapdragon machine (Nexus 5). My current hooker implementation is here.

https://github.com/perillamint/hideroot/blob/8c66dd8d515e0c8506ec6d229f296a8a1d24f293/gphook.c

I tested this code with Galaxy Note 2 (exynos 4412) and it works(Print Awesome! when sys_open is called. code: https://github.com/perillamint/hideroot/blob/8c66dd8d515e0c8506ec6d229f296a8a1d24f293/main.c). But when I run this code in Nexus 5 (MSM8974), instruction cache seems does not flushed at all.

How can I flush snapdragon's instruction cache?