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| author | Valentin Schneider <valentin.schneider@arm.com> | 2020-07-30 20:03:21 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2020-09-06 20:26:13 +0300 |
| commit | 1b57d91b969cda1d2c3530f2e829ca366a9c7df7 (patch) | |
| tree | 52a46c1f82675a333d6e771e8e194e6947b9625f /drivers/irqchip/irq-gic.c | |
| parent | 5f774f5e12512b850a611aa99b4601d7eac50edb (diff) | |
| download | linux-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.c | 6 |
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; } |