Merge branch 'stable/irq.rework' into stable/irq.cleanup

* stable/irq.rework:
  xen/irq: Cleanup up the pirq_to_irq for DomU PV PCI passthrough guests as well.
  xen: Use IRQF_FORCE_RESUME
  xen/timer: Missing IRQF_NO_SUSPEND in timer code broke suspend.
  xen: Fix compile error introduced by "switch to new irq_chip functions"
  xen: Switch to new irq_chip functions
  xen: Remove stale irq_chip.end
  xen: events: do not free legacy IRQs
  xen: events: allocate GSIs and dynamic IRQs from separate IRQ ranges.
  xen: events: add xen_allocate_irq_{dynamic, gsi} and xen_free_irq
  xen:events: move find_unbound_irq inside CONFIG_PCI_MSI
  xen: handled remapped IRQs when enabling a pcifront PCI device.
  genirq: Add IRQF_FORCE_RESUME

arch/x86/pci/xen.c

@@ -226,21 +226,27 @@ static int xen_pcifront_enable_irq(struct pci_dev *dev)
 {
 	int rc;
 	int share = 1;
+	u8 gsi;
 
-	dev_info(&dev->dev, "Xen PCI enabling IRQ: %d\n", dev->irq);
-
-	if (dev->irq < 0)
-		return -EINVAL;
+	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
+	if (rc < 0) {
+		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
+			 rc);
+		return rc;
+	}
 
-	if (dev->irq < NR_IRQS_LEGACY)
+	if (gsi < NR_IRQS_LEGACY)
 		share = 0;
 
-	rc = xen_allocate_pirq(dev->irq, share, "pcifront");
+	rc = xen_allocate_pirq(gsi, share, "pcifront");
 	if (rc < 0) {
-		dev_warn(&dev->dev, "Xen PCI IRQ: %d, failed to register:%d\n",
-			 dev->irq, rc);
+		dev_warn(&dev->dev, "Xen PCI: failed to register GSI%d: %d\n",
+			 gsi, rc);
 		return rc;
 	}
+
+	dev->irq = rc;
+	dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
 	return 0;
 }
 

arch/x86/xen/time.c

@@ -397,7 +397,9 @@ void xen_setup_timer(int cpu)
 		name = "<timer kasprintf failed>";
 
 	irq = bind_virq_to_irqhandler(VIRQ_TIMER, cpu, xen_timer_interrupt,
-				      IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING|IRQF_TIMER,
+				      IRQF_DISABLED|IRQF_PERCPU|
+				      IRQF_NOBALANCING|IRQF_TIMER|
+				      IRQF_FORCE_RESUME,
 				      name, NULL);
 
 	evt = &per_cpu(xen_clock_events, cpu);

include/linux/interrupt.h

@@ -55,7 +55,7 @@
  *                Used by threaded interrupts which need to keep the
  *                irq line disabled until the threaded handler has been run.
  * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend
- *
+ * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
  */
 #define IRQF_DISABLED		0x00000020
 #define IRQF_SAMPLE_RANDOM	0x00000040
@@ -67,6 +67,7 @@
 #define IRQF_IRQPOLL		0x00001000
 #define IRQF_ONESHOT		0x00002000
 #define IRQF_NO_SUSPEND		0x00004000
+#define IRQF_FORCE_RESUME	0x00008000
 
 #define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND)
 

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:

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);