genirq/msi: Remove unused MSI_FLAG_IDENTITY_MAP

BugLink: http://bugs.launchpad.net/bugs/1621113

commit b6140914 upstream.

No user and we definitely don't want to grow one.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: linux-block@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: axboe@fb.com
Cc: agordeev@redhat.com
Link: http://lkml.kernel.org/r/1467621574-8277-2-git-send-email-hch@lst.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

include/linux/msi.h

@@ -254,12 +254,10 @@ enum {
 	 * callbacks.
 	 */
 	MSI_FLAG_USE_DEF_CHIP_OPS	= (1 << 1),
-	/* Build identity map between hwirq and irq */
-	MSI_FLAG_IDENTITY_MAP		= (1 << 2),
 	/* Support multiple PCI MSI interrupts */
-	MSI_FLAG_MULTI_PCI_MSI		= (1 << 3),
+	MSI_FLAG_MULTI_PCI_MSI		= (1 << 2),
 	/* Support PCI MSIX interrupts */
-	MSI_FLAG_PCI_MSIX		= (1 << 4),
+	MSI_FLAG_PCI_MSIX		= (1 << 3),
 };
 
 int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,

kernel/irq/msi.c

@@ -268,7 +268,7 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 	struct msi_domain_ops *ops = info->ops;
 	msi_alloc_info_t arg;
 	struct msi_desc *desc;
-	int i, ret, virq = -1;
+	int i, ret, virq;
 
 	ret = ops->msi_check(domain, info, dev);
 	if (ret == 0)
@@ -278,12 +278,8 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 
 	for_each_msi_entry(desc, dev) {
 		ops->set_desc(&arg, desc);
-		if (info->flags & MSI_FLAG_IDENTITY_MAP)
-			virq = (int)ops->get_hwirq(info, &arg);
-		else
-			virq = -1;
 
-		virq = __irq_domain_alloc_irqs(domain, virq, desc->nvec_used,
+		virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
 					       dev_to_node(dev), &arg, false);
 		if (virq < 0) {
 			ret = -ENOSPC;