genirq/msi: Make use of affinity aware allocations

Allow the MSI code to provide affinity hints per MSI descriptor.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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/1467621574-8277-6-git-send-email-hch@lst.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/msi.h

@@ -47,6 +47,7 @@ struct fsl_mc_msi_desc {
  * @nvec_used:	The number of vectors used
  * @dev:	Pointer to the device which uses this descriptor
  * @msg:	The last set MSI message cached for reuse
+ * @affinity:	Optional pointer to a cpu affinity mask for this descriptor
  *
  * @masked:	[PCI MSI/X] Mask bits
  * @is_msix:	[PCI MSI/X] True if MSI-X
@@ -67,6 +68,7 @@ struct msi_desc {
 	unsigned int			nvec_used;
 	struct device			*dev;
 	struct msi_msg			msg;
+	const struct cpumask		*affinity;
 
 	union {
 		/* PCI MSI/X specific data */

kernel/irq/msi.c

@@ -335,7 +335,7 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 
 		virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
 					       dev_to_node(dev), &arg, false,
-					       NULL);
+					       desc->affinity);
 		if (virq < 0) {
 			ret = -ENOSPC;
 			if (ops->handle_error)