x86, irq, PCI: Keep IRQ assignment for runtime power management

Now IOAPIC driver dynamically allocates IRQ numbers for IOAPIC pins.
We need to keep IRQ assignment for PCI devices during runtime power
management, otherwise it may cause failure of device wakeups.

Commit 3eec595235 "x86, irq, PCI: Keep IRQ assignment for PCI
devices during suspend/hibernation" has fixed the issue for suspend/
hibernation, we also need the same fix for runtime device sleep too.

Fix: https://bugzilla.kernel.org/show_bug.cgi?id=83271
Reported-and-Tested-by: EmanueL Czirai <amanual@openmailbox.org>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: EmanueL Czirai <amanual@openmailbox.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Grant Likely <grant.likely@linaro.org>
Link: http://lkml.kernel.org/r/1409304383-18806-1-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/apic/io_apic.c

@@ -3959,6 +3959,18 @@ int mp_set_gsi_attr(u32 gsi, int trigger, int polarity, int node)
 	return ret;
 }
 
+bool mp_should_keep_irq(struct device *dev)
+{
+	if (dev->power.is_prepared)
+		return true;
+#ifdef	CONFIG_PM_RUNTIME
+	if (dev->power.runtime_status == RPM_SUSPENDING)
+		return true;
+#endif
+
+	return false;
+}
+
 /* Enable IOAPIC early just for system timer */
 void __init pre_init_apic_IRQ0(void)
 {