genirq: Add and use an irq_data_update_affinity helper

Some architectures and irqchip drivers modify the cpumask returned by
irq_data_get_affinity_mask, usually by copying in to it. This is
problematic for uniprocessor configurations, where the affinity mask
should be constant, as it is known at compile time.

Add and use a setter for the affinity mask, following the pattern of
irq_data_update_effective_affinity. This allows the getter function to
return a const cpumask pointer.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Xen bits
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220701200056.46555-7-samuel@sholland.org

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/irqchip/irq-bcm6345-l1.c b/drivers/irqchip/irq-bcm6345-l1.c
index 142a7431745f..6899e37810a8 100644
--- a/drivers/irqchip/irq-bcm6345-l1.c
+++ b/drivers/irqchip/irq-bcm6345-l1.c
@@ -216,11 +216,11 @@ static int bcm6345_l1_set_affinity(struct irq_data *d,
 		enabled = intc->cpus[old_cpu]->enable_cache[word] & mask;
 		if (enabled)
 			__bcm6345_l1_mask(d);
-		cpumask_copy(irq_data_get_affinity_mask(d), dest);
+		irq_data_update_affinity(d, dest);
 		if (enabled)
 			__bcm6345_l1_unmask(d);
 	} else {
-		cpumask_copy(irq_data_get_affinity_mask(d), dest);
+		irq_data_update_affinity(d, dest);
 	}
 	raw_spin_unlock_irqrestore(&intc->lock, flags);