genirq: Move suspend/resume logic into irq/pm code

No functional change. Preparatory patch for cleaning up the suspend
abort functionality. Update the comments while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 38 insertions, 6 deletions

diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index abcd6ca86cb7..b84141dcee5e 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -13,13 +13,26 @@
 
 #include "internals.h"
 
+static void suspend_device_irq(struct irq_desc *desc, int irq)
+{
+        if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
+                return;
+
+        desc->istate |= IRQS_SUSPENDED;
+        __disable_irq(desc, irq);
+}
+
 /**
  * suspend_device_irqs - disable all currently enabled interrupt lines
  *
- * During system-wide suspend or hibernation device drivers need to be prevented
- * from receiving interrupts and this function is provided for this purpose.
- * It marks all interrupt lines in use, except for the timer ones, as disabled
- * and sets the IRQS_SUSPENDED flag for each of them.
+ * During system-wide suspend or hibernation device drivers need to be
+ * prevented from receiving interrupts and this function is provided
+ * for this purpose.
+ *
+ * So we disable all interrupts and mark them IRQS_SUSPENDED except
+ * for those which are unused and those which are marked as not
+ * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND
+ * set.
  */
 void suspend_device_irqs(void)
 {
@@ -30,7 +43,7 @@ void suspend_device_irqs(void)
                 unsigned long flags;
 
                 raw_spin_lock_irqsave(&desc->lock, flags);
-                __disable_irq(desc, irq, true);
+                suspend_device_irq(desc, irq);
                 raw_spin_unlock_irqrestore(&desc->lock, flags);
         }
 
@@ -40,6 +53,25 @@ void suspend_device_irqs(void)
 }
 EXPORT_SYMBOL_GPL(suspend_device_irqs);
 
+static void resume_irq(struct irq_desc *desc, int irq)
+{
+        if (desc->istate & IRQS_SUSPENDED)
+                goto resume;
+
+        if (!desc->action)
+                return;
+
+        /* Interrupts marked with that flag are force reenabled */
+        if (!(desc->action->flags & IRQF_FORCE_RESUME))
+                return;
+
+        /* Pretend that it got disabled ! */
+        desc->depth++;
+resume:
+        desc->istate &= ~IRQS_SUSPENDED;
+        __enable_irq(desc, irq);
+}
+
 static void resume_irqs(bool want_early)
 {
         struct irq_desc *desc;
@@ -54,7 +86,7 @@ static void resume_irqs(bool want_early)
                         continue;
 
                 raw_spin_lock_irqsave(&desc->lock, flags);
-                __enable_irq(desc, irq, true);
+                resume_irq(desc, irq);
                 raw_spin_unlock_irqrestore(&desc->lock, flags);
         }
 }