4.17-stable review patch. If anyone has any objections, please let me know.
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From: Yang Yingliang yangyingliang@huawei.com
commit c1797b11a09c8323c92b074fd48b89a936c991d0 upstream.
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, pick an online CPU (and the first one will do).
But on some systems, binding an LPI to non-local node CPU may cause deadlock (see Cavium erratum 23144). In this case, just fail the activate and return an error code.
Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Jason Cooper jason@lakedaemon.net Cc: Alexandre Belloni alexandre.belloni@bootlin.com Cc: Sumit Garg sumit.garg@linaro.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180622095254.5906-5-marc.zyngier@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/irqchip/irq-gic-v3-its.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -2309,7 +2309,14 @@ static int its_irq_domain_activate(struc 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));