genirq: Add IRQF_FORCE_RESUME

Xen needs to reenable interrupts which are marked IRQF_NO_SUSPEND in the
resume path. Add a flag to force the reenabling in the resume code.

Tested-and-acked-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 10 insertions, 4 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0caa59f747dd..b4198ee8cfdf 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -282,8 +282,17 @@ EXPORT_SYMBOL(disable_irq);
 
 void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
 {
-        if (resume)
+        if (resume) {
+                if (!(desc->status & IRQ_SUSPENDED)) {
+                        if (!desc->action)
+                                return;
+                        if (!(desc->action->flags & IRQF_FORCE_RESUME))
+                                return;
+                        /* Pretend that it got disabled ! */
+                        desc->depth++;
+                }
                 desc->status &= ~IRQ_SUSPENDED;
+        }
 
         switch (desc->depth) {
         case 0:
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index 0d4005d85b03..d6bfb89cce91 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -53,9 +53,6 @@ void resume_device_irqs(void)
         for_each_irq_desc(irq, desc) {
                 unsigned long flags;
 
-                if (!(desc->status & IRQ_SUSPENDED))
-                        continue;
-
                 raw_spin_lock_irqsave(&desc->lock, flags);
                 __enable_irq(desc, irq, true);
                 raw_spin_unlock_irqrestore(&desc->lock, flags);