hpsa: set irq affinity hints to route MSI-X vectors across CPUs

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Mike Miller <michael.miller@canonical.com>
Reviewed-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/hpsa.c

@@ -6615,6 +6615,17 @@ static void hpsa_free_cmd_pool(struct ctlr_info *h)
 			h->ioaccel_cmd_pool, h->ioaccel_cmd_pool_dhandle);
 }
 
+static void hpsa_irq_affinity_hints(struct ctlr_info *h)
+{
+	int i, cpu, rc;
+
+	cpu = cpumask_first(cpu_online_mask);
+	for (i = 0; i < h->msix_vector; i++) {
+		rc = irq_set_affinity_hint(h->intr[i], get_cpu_mask(cpu));
+		cpu = cpumask_next(cpu, cpu_online_mask);
+	}
+}
+
 static int hpsa_request_irq(struct ctlr_info *h,
 	irqreturn_t (*msixhandler)(int, void *),
 	irqreturn_t (*intxhandler)(int, void *))
@@ -6634,6 +6645,7 @@ static int hpsa_request_irq(struct ctlr_info *h,
 			rc = request_irq(h->intr[i], msixhandler,
 					0, h->devname,
 					&h->q[i]);
+		hpsa_irq_affinity_hints(h);
 	} else {
 		/* Use single reply pool */
 		if (h->msix_vector > 0 || h->msi_vector) {
@@ -6685,12 +6697,15 @@ static void free_irqs(struct ctlr_info *h)
 	if (!h->msix_vector || h->intr_mode != PERF_MODE_INT) {
 		/* Single reply queue, only one irq to free */
 		i = h->intr_mode;
+		irq_set_affinity_hint(h->intr[i], NULL);
 		free_irq(h->intr[i], &h->q[i]);
 		return;
 	}
 
-	for (i = 0; i < h->msix_vector; i++)
+	for (i = 0; i < h->msix_vector; i++) {
+		irq_set_affinity_hint(h->intr[i], NULL);
 		free_irq(h->intr[i], &h->q[i]);
+	}
 }
 
 static void hpsa_free_irqs_and_disable_msix(struct ctlr_info *h)