[PATCH 4.9 134/206] irqchip/bcm7038-l1: Implement irq_cpu_offline() callback

From: Greg Kroah-Hartman
Date: Tue Jan 10 2017 - 09:29:31 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Florian Fainelli <f.fainelli@xxxxxxxxx>

commit 34c535793bcbf9263cf22f8a52101f796cdfab8e upstream.

We did not implement an irq_cpu_offline callback for our irqchip, yet we
support setting a given IRQ's affinity. This resulted in interrupts
whose affinity mask included CPUs being taken offline not to work
correctly once the CPU had been put offline.

Fixes: 5f7f0317ed28 ("IRQCHIP: Add new driver for BCM7038-style level 1 interrupt controllers")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: jason@xxxxxxxxxxxxxx
Cc: marc.zyngier@xxxxxxx
Cc: cernekee@xxxxxxxxx
Cc: jaedon.shin@xxxxxxxxx
Cc: ralf@xxxxxxxxxxxxxx
Cc: justinpopo6@xxxxxxxxx
Link: http://lkml.kernel.org/r/1477948656-12966-2-git-send-email-f.fainelli@xxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/irqchip/irq-bcm7038-l1.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

--- a/drivers/irqchip/irq-bcm7038-l1.c
+++ b/drivers/irqchip/irq-bcm7038-l1.c
@@ -215,6 +215,31 @@ static int bcm7038_l1_set_affinity(struc
return 0;
}

+static void bcm7038_l1_cpu_offline(struct irq_data *d)
+{
+ struct cpumask *mask = irq_data_get_affinity_mask(d);
+ int cpu = smp_processor_id();
+ cpumask_t new_affinity;
+
+ /* This CPU was not on the affinity mask */
+ if (!cpumask_test_cpu(cpu, mask))
+ return;
+
+ if (cpumask_weight(mask) > 1) {
+ /*
+ * Multiple CPU affinity, remove this CPU from the affinity
+ * mask
+ */
+ cpumask_copy(&new_affinity, mask);
+ cpumask_clear_cpu(cpu, &new_affinity);
+ } else {
+ /* Only CPU, put on the lowest online CPU */
+ cpumask_clear(&new_affinity);
+ cpumask_set_cpu(cpumask_first(cpu_online_mask), &new_affinity);
+ }
+ irq_set_affinity_locked(d, &new_affinity, false);
+}
+
static int __init bcm7038_l1_init_one(struct device_node *dn,
unsigned int idx,
struct bcm7038_l1_chip *intc)
@@ -266,6 +291,7 @@ static struct irq_chip bcm7038_l1_irq_ch
.irq_mask = bcm7038_l1_mask,
.irq_unmask = bcm7038_l1_unmask,
.irq_set_affinity = bcm7038_l1_set_affinity,
+ .irq_cpu_offline = bcm7038_l1_cpu_offline,
};

static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,