Add helper function to detect VT-d Posted-Interrupts capability.
Signed-off-by: NFeng Wu <feng.wu@intel.com>
Reviewed-by: NJiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Acked-by: NJoerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org
Cc: dwmw2@infradead.org
Link: http://lkml.kernel.org/r/1433827237-3382-8-git-send-email-feng.wu@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>