irqchip/armada-370-xp: Fix support for Multi-MSI interrupts

irq-armada-370-xp driver already sets MSI_FLAG_MULTI_PCI_MSI flag into
msi_domain_info structure. But allocated interrupt numbers for Multi-MSI
needs to be properly aligned otherwise devices send MSI interrupt with
wrong number.

Fix this issue by using function bitmap_find_free_region() instead of
bitmap_find_next_zero_area() to allocate aligned interrupt numbers.

Signed-off-by: Pali Rohár <[e-mail]>
Fixes: a71b9412c90c ("irqchip/armada-370-xp: Allow allocation of multiple MSIs")
Cc: [e-mail]
Signed-off-by: Marc Zyngier <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/irqchip/irq-armada-370-xp.c

···
 	int hwirq, i;
 
 	mutex_lock(&msi_used_lock);
-
-	hwirq = bitmap_find_next_zero_area(msi_used, PCI_MSI_DOORBELL_NR,
-					   0, nr_irqs, 0);
-	if (hwirq >= PCI_MSI_DOORBELL_NR) {
-		mutex_unlock(&msi_used_lock);
-		return -ENOSPC;
-	}
-
-	bitmap_set(msi_used, hwirq, nr_irqs);
+	hwirq = bitmap_find_free_region(msi_used, PCI_MSI_DOORBELL_NR,
+					order_base_2(nr_irqs));
 	mutex_unlock(&msi_used_lock);
+
+	if (hwirq < 0)
+		return -ENOSPC;
 
 	for (i = 0; i < nr_irqs; i++) {
 		irq_domain_set_info(domain, virq + i, hwirq + i,
···
 	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
 
 	mutex_lock(&msi_used_lock);
-	bitmap_clear(msi_used, d->hwirq, nr_irqs);
+	bitmap_release_region(msi_used, d->hwirq, order_base_2(nr_irqs));
 	mutex_unlock(&msi_used_lock);
 }