[PATCH v3] irqchip/gic-v3-its: fix ITS queue timeout

[PATCH v3] irqchip/gic-v3-its: fix ITS queue timeout

[Yang Yingliang]

On a NUMA system, if an ITS is local to an offline
node, the ITS driver may pick an offline CPU to bind
the LPI. In this case, we need to pick an online CPU.
But on some systems, binding LPI to non-local node
CPU will cause deadlock. In this case, we don't
bind the LPI to any online CPU and return an error code.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 5416f2b..137c433 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2309,7 +2309,13 @@ static int its_irq_domain_activate(struct irq_domain *domain,
 		cpu_mask = cpumask_of_node(its_dev->its->numa_node);
 
 	/* Bind the LPI to the first possible CPU */
-	cpu = cpumask_first(cpu_mask);
+	cpu = cpumask_first_and(cpu_mask, cpu_online_mask);
+	if (cpu >= nr_cpu_ids) {
+		if (its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144)
+			return -EINVAL;
+
+		cpu = cpumask_first(cpu_online_mask);
+	}
 	its_dev->event_map.col_map[event] = cpu;
 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
 
-- 
1.8.3

[PATCH v3] irqchip/gic-v3-its: fix ITS queue timeout

[Marc Zyngier]

On 11/06/18 13:25, Yang Yingliang wrote:
> On a NUMA system, if an ITS is local to an offline
> node, the ITS driver may pick an offline CPU to bind
> the LPI. In this case, we need to pick an online CPU.
> But on some systems, binding LPI to non-local node
> CPU will cause deadlock. In this case, we don't
> bind the LPI to any online CPU and return an error code.
> 
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
>  drivers/irqchip/irq-gic-v3-its.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 5416f2b..137c433 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -2309,7 +2309,13 @@ static int its_irq_domain_activate(struct irq_domain *domain,
>  		cpu_mask = cpumask_of_node(its_dev->its->numa_node);
>  
>  	/* Bind the LPI to the first possible CPU */
> -	cpu = cpumask_first(cpu_mask);
> +	cpu = cpumask_first_and(cpu_mask, cpu_online_mask);
> +	if (cpu >= nr_cpu_ids) {
> +		if (its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144)
> +			return -EINVAL;
> +
> +		cpu = cpumask_first(cpu_online_mask);
> +	}
>  	its_dev->event_map.col_map[event] = cpu;
>  	irq_data_update_effective_affinity(d, cpumask_of(cpu));
>  
> 

Queued as a fix for 4.18 with a slightly updated change-log and a cc to
stable.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...