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| author | Valentin Schneider <valentin.schneider@arm.com> | 2020-07-30 18:03:20 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2020-09-06 18:26:13 +0100 |
| commit | 17f644e949ffb14e9c8870d99bc574066d8b685c (patch) | |
| tree | 5b37279a9bf9925fd018893cd9fed4f1c2b57abe /drivers/irqchip/irq-gic-v3.c | |
| parent | cd1752d34ef33d68d82ef9dcc699b4eaa17c07fc (diff) | |
| download | linux-17f644e949ffb14e9c8870d99bc574066d8b685c.tar.bz2 | |
irqchip/gic-v2, v3: Implement irq_chip->irq_retrigger()
While digging around IRQCHIP_EOI_IF_HANDLED and irq/resend.c, it has come
to my attention that the IRQ resend situation seems a bit precarious for
the GIC(s).
When marking an IRQ with IRQS_PENDING, handle_fasteoi_irq() will bail out
and issue an irq_eoi(). Should the IRQ in question be re-enabled,
check_irq_resend() will trigger a SW resend, which will go through the flow
handler again and issue *another* irq_eoi() on the *same* IRQ
activation. This is something the GIC spec clearly describes as a bad idea:
any EOI must match a previous ACK.
Implement irq_chip.irq_retrigger() for the GIC chips by setting the GIC
pending bit of the relevant IRQ. After being called by check_irq_resend(),
this will eventually trigger a *new* interrupt which we will handle as usual.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200730170321.31228-2-valentin.schneider@arm.com
Diffstat (limited to 'drivers/irqchip/irq-gic-v3.c')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 324f280ff606..b507bc7c5cda 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -1207,6 +1207,11 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val, #define gic_smp_init() do { } while(0) #endif +static int gic_retrigger(struct irq_data *data) +{ + return !gic_irq_set_irqchip_state(data, IRQCHIP_STATE_PENDING, true); +} + #ifdef CONFIG_CPU_PM static int gic_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd, void *v) @@ -1242,6 +1247,7 @@ static struct irq_chip gic_chip = { .irq_eoi = gic_eoi_irq, .irq_set_type = gic_set_type, .irq_set_affinity = gic_set_affinity, + .irq_retrigger = gic_retrigger, .irq_get_irqchip_state = gic_irq_get_irqchip_state, .irq_set_irqchip_state = gic_irq_set_irqchip_state, .irq_nmi_setup = gic_irq_nmi_setup, @@ -1258,6 +1264,7 @@ static struct irq_chip gic_eoimode1_chip = { .irq_eoi = gic_eoimode1_eoi_irq, .irq_set_type = gic_set_type, .irq_set_affinity = gic_set_affinity, + .irq_retrigger = gic_retrigger, .irq_get_irqchip_state = gic_irq_get_irqchip_state, .irq_set_irqchip_state = gic_irq_set_irqchip_state, .irq_set_vcpu_affinity = gic_irq_set_vcpu_affinity, |