From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Wed, 20 Dec 2017 09:26:10 +0000 Subject: [PATCH] irqchip/gic-v3-its: Flush GICR caching for a cross node collection move of an irq In-Reply-To: <20171220091544.4467-1-ganapatrao.kulkarni@cavium.com> References: <20171220091544.4467-1-ganapatrao.kulkarni@cavium.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 20/12/17 09:15, Ganapatrao Kulkarni wrote: > When an interrupt is moved, it is possible that an implementation that > supports caching might still have cached data for a previous > (no longer valid) mapping of the interrupt. In particular, in a distributed > GIC implementation like multi-socket SoC platfroms. Hence it is necessary > to flush cached entries after cross node collection migration. > > Signed-off-by: Ganapatrao Kulkarni > --- > drivers/irqchip/irq-gic-v3-its.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index 4039e64..ea849a1 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -1119,6 +1119,12 @@ static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val, > if (cpu != its_dev->event_map.col_map[id]) { > target_col = &its_dev->its->collections[cpu]; > its_send_movi(its_dev, target_col, id); > + /* Issue INV for cross node collection move on > + * multi socket systems. > + */ > + if (cpu_to_node(cpu) != > + cpu_to_node(its_dev->event_map.col_map[id])) > + its_send_inv(its_dev, id); > its_dev->event_map.col_map[id] = cpu; > irq_data_update_effective_affinity(d, cpumask_of(cpu)); > } > The MOVI command doesn't have any such requirement (it only mandates synchronization), and doesn't say anything about distributed vs monolithic. What am I missing? M. -- Jazz is not dead. It just smells funny...