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authorValentin Schneider <valentin.schneider@arm.com>2020-07-30 20:03:21 +0300
committerMarc Zyngier <maz@kernel.org>2020-09-06 20:26:13 +0300
commit1b57d91b969cda1d2c3530f2e829ca366a9c7df7 (patch)
tree52a46c1f82675a333d6e771e8e194e6947b9625f /drivers/irqchip/irq-gic.c
parent5f774f5e12512b850a611aa99b4601d7eac50edb (diff)
downloadlinux-1b57d91b969cda1d2c3530f2e829ca366a9c7df7.tar.xz
irqchip/gic-v2, v3: Prevent SW resends entirely
The GIC irqchips can now use a HW resend when a retrigger is invoked by check_irq_resend(). However, should the HW resend fail, check_irq_resend() will still attempt to trigger a SW resend, which is still a bad idea for the GICs. Prevent this from happening by setting IRQD_HANDLE_ENFORCE_IRQCTX on all GIC IRQs. Technically per-cpu IRQs do not need this, as their flow handlers never set IRQS_PENDING, but this aligns all IRQs wrt context enforcement: this also forces all GIC IRQ handling to happen in IRQ context (as defined by in_irq()). Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200730170321.31228-3-valentin.schneider@arm.com
Diffstat (limited to 'drivers/irqchip/irq-gic.c')
-rw-r--r--drivers/irqchip/irq-gic.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index e92ee2b6d7a5..b59bcef69bf3 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -975,6 +975,7 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hw)
{
struct gic_chip_data *gic = d->host_data;
+ struct irq_data *irqd = irq_desc_get_irq_data(irq_to_desc(irq));
if (hw < 32) {
irq_set_percpu_devid(irq);
@@ -984,8 +985,11 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
irq_domain_set_info(d, irq, hw, &gic->chip, d->host_data,
handle_fasteoi_irq, NULL, NULL);
irq_set_probe(irq);
- irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq)));
+ irqd_set_single_target(irqd);
}
+
+ /* Prevents SW retriggers which mess up the ACK/EOI ordering */
+ irqd_set_handle_enforce_irqctx(irqd);
return 0;
}