[PATCH] irqchip/irq-csky-mpintc: Support auto irq deliver to all cpus

[guoren@kernel.org]

From: Guo Ren <ren_guo@c-sky.com>

The csky,mpintc could deliver a external irq to one cpu or all cpus, but
it couldn't deliver a external irq to a group of cpus with cpu_mask. So
we only use auto deliver mode when affinity mask_val is equal to
cpu_present_mask.

There is no limitation for only two cpus in SMP system.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-csky-mpintc.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-csky-mpintc.c b/drivers/irqchip/irq-csky-mpintc.c
index 5bc0868..a3dbc6b 100644
--- a/drivers/irqchip/irq-csky-mpintc.c
+++ b/drivers/irqchip/irq-csky-mpintc.c
@@ -159,8 +159,19 @@ static int csky_irq_set_affinity(struct irq_data *d,
 	if (cpu >= nr_cpu_ids)
 		return -EINVAL;
 
-	/* Enable interrupt destination */
-	cpu |= BIT(31);
+	/*
+	 * The csky,mpintc could support auto irq deliver, but it only
+	 * could deliver external irq to one cpu or all cpus. So it
+	 * doesn't support deliver external irq to a group of cpus
+	 * with cpu_mask.
+	 * SO we only use auto deliver mode when affinity mask_val is
+	 * equal to cpu_present_mask.
+	 *
+	 */
+	if (cpumask_equal(mask_val, cpu_present_mask))
+		cpu = 0;
+	else
+		cpu |= BIT(31);
 
 	writel_relaxed(cpu, INTCG_base + INTCG_CIDSTR + offset);
 
-- 
2.7.4