From: Valentin Schneider <valentin.schnei...@arm.com> 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.schnei...@arm.com> Signed-off-by: Marc Zyngier <m...@kernel.org> Link: https://lore.kernel.org/r/20200730170321.31228-3-valentin.schnei...@arm.com --- drivers/irqchip/irq-gic-v3.c | 5 ++++- drivers/irqchip/irq-gic.c | 6 +++++- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index b507bc7c5cda..4e9387aafed8 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -1279,6 +1279,7 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) { struct irq_chip *chip = &gic_chip; + struct irq_data *irqd = irq_desc_get_irq_data(irq_to_desc(irq)); if (static_branch_likely(&supports_deactivate_key)) chip = &gic_eoimode1_chip; @@ -1296,7 +1297,7 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, irq_domain_set_info(d, irq, hw, 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); break; case LPI_RANGE: @@ -1310,6 +1311,8 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, return -EPERM; } + /* Prevents SW retriggers which mess up the ACK/EOI ordering */ + irqd_set_handle_enforce_irqctx(irqd); return 0; } 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; } -- 2.28.0
