s390/pci: add zpci_set_irq()/zpci_clear_irq()

Pull the directed vs floating IRQ check into common
zpci_set_irq()/zpci_clear_irq() functions and expose them for the rest
of the zPCI subsystem. Furthermore we add a zdev flag bit to easily
check if IRQs are registered. This is needed for use in resetting a zPCI
function.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/include/asm/pci.h

@@ -133,7 +133,8 @@ struct zpci_dev {
 	u8		has_resources	: 1;
 	u8		is_physfn	: 1;
 	u8		util_str_avail	: 1;
-	u8		reserved	: 3;
+	u8		irqs_registered	: 1;
+	u8		reserved	: 2;
 	unsigned int	devfn;		/* DEVFN part of the RID*/
 
 	struct mutex lock;
@@ -271,9 +272,13 @@ struct zpci_dev *get_zdev_by_fid(u32);
 int zpci_dma_init(void);
 void zpci_dma_exit(void);
 
+/* IRQ */
 int __init zpci_irq_init(void);
 void __init zpci_irq_exit(void);
 
+int zpci_set_irq(struct zpci_dev *zdev);
+int zpci_clear_irq(struct zpci_dev *zdev);
+
 /* FMB */
 int zpci_fmb_enable_device(struct zpci_dev *);
 int zpci_fmb_disable_device(struct zpci_dev *);

arch/s390/pci/pci_irq.c

@@ -35,7 +35,7 @@ static struct airq_iv *zpci_sbv;
  */
 static struct airq_iv **zpci_ibv;
 
-/* Modify PCI: Register adapter interruptions */
+/* Modify PCI: Register floating adapter interruptions */
 static int zpci_set_airq(struct zpci_dev *zdev)
 {
 	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT);
@@ -53,7 +53,7 @@ static int zpci_set_airq(struct zpci_dev *zdev)
 	return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
 }
 
-/* Modify PCI: Unregister adapter interruptions */
+/* Modify PCI: Unregister floating adapter interruptions */
 static int zpci_clear_airq(struct zpci_dev *zdev)
 {
 	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT);
@@ -98,6 +98,38 @@ static int zpci_clear_directed_irq(struct zpci_dev *zdev)
 	return cc ? -EIO : 0;
 }
 
+/* Register adapter interruptions */
+int zpci_set_irq(struct zpci_dev *zdev)
+{
+	int rc;
+
+	if (irq_delivery == DIRECTED)
+		rc = zpci_set_directed_irq(zdev);
+	else
+		rc = zpci_set_airq(zdev);
+
+	if (!rc)
+		zdev->irqs_registered = 1;
+
+	return rc;
+}
+
+/* Clear adapter interruptions */
+int zpci_clear_irq(struct zpci_dev *zdev)
+{
+	int rc;
+
+	if (irq_delivery == DIRECTED)
+		rc = zpci_clear_directed_irq(zdev);
+	else
+		rc = zpci_clear_airq(zdev);
+
+	if (!rc)
+		zdev->irqs_registered = 0;
+
+	return rc;
+}
+
 static int zpci_set_irq_affinity(struct irq_data *data, const struct cpumask *dest,
 				 bool force)
 {
@@ -311,10 +343,7 @@ int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 	zdev->msi_first_bit = bit;
 	zdev->msi_nr_irqs = msi_vecs;
 
-	if (irq_delivery == DIRECTED)
-		rc = zpci_set_directed_irq(zdev);
-	else
-		rc = zpci_set_airq(zdev);
+	rc = zpci_set_irq(zdev);
 	if (rc)
 		return rc;
 
@@ -328,10 +357,7 @@ void arch_teardown_msi_irqs(struct pci_dev *pdev)
 	int rc;
 
 	/* Disable interrupts */
-	if (irq_delivery == DIRECTED)
-		rc = zpci_clear_directed_irq(zdev);
-	else
-		rc = zpci_clear_airq(zdev);
+	rc = zpci_clear_irq(zdev);
 	if (rc)
 		return;