[PATCH 4.2.y-ckt 087/206] irqchip/gic: Ensure ordering between read of INTACK and shared data

4.2.8-ckt12 -stable review patch. If anyone has any objections, please let me know. ---8< From: Will Deacon commit f86c4fbd930ff6fecf3d8a1c313182bd0f49f496 upstream. When an IPI is generated by a CPU, the

[PATCH 4.2.y-ckt 087/206] irqchip/gic: Ensure ordering between read of INTACK and shared data

4.2.8-ckt12 -stable review patch. If anyone has any objections, please let me know. ---8< From: Will Deacon commit f86c4fbd930ff6fecf3d8a1c313182bd0f49f496 upstream. When an IPI is generated by a CPU, the pattern looks roughly