Messages in this thread Patch in this message |  | | Date | Sat, 25 Jul 2020 13:30:55 +0100 | From | Marc Zyngier <> | Subject | Re: [PATCH V2] genirq/affinity: Handle affinity setting on inactive interrupts correctly |
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Hi Thomas,
On Fri, 24 Jul 2020 21:44:41 +0100, Thomas Gleixner <tglx@linutronix.de> wrote: > > John, > > Thomas Gleixner <tglx@linutronix.de> writes: > > I have some ideas for a trivial generic way to solve this without > > undoing the commit in question and without going through all the irq > > chip drivers. So far everything I came up with is butt ugly. Maybe Marc > > has some brilliant idea. > > > > Sorry for the wreckage and thanks for the excellent problem > > description. I'll come back to you in the next days. > > couldn't give up :) > > So after staring in too many drivers, I resorted to make this mode > opt-in and mark the interrupts accordingly for the two drivers which are > known to want this. Not that I love it, but it's the least dangerous > option. Completely untested patch below. > > Thanks, > > tglx > --- > arch/x86/kernel/apic/vector.c | 4 ++++ > drivers/irqchip/irq-gic-v3-its.c | 5 ++++- > include/linux/irq.h | 13 +++++++++++++ > kernel/irq/manage.c | 6 +++++- > 4 files changed, 26 insertions(+), 2 deletions(-) > > --- a/arch/x86/kernel/apic/vector.c > +++ b/arch/x86/kernel/apic/vector.c > @@ -560,6 +560,10 @@ static int x86_vector_alloc_irqs(struct > * as that can corrupt the affinity move state. > */ > irqd_set_handle_enforce_irqctx(irqd); > + > + /* Don't invoke affinity setter on deactivated interrupts */ > + irqd_set_affinity_on_activate(irqd); > + > /* > * Legacy vectors are already assigned when the IOAPIC > * takes them over. They stay on the same vector. This is > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -3523,6 +3523,7 @@ static int its_irq_domain_alloc(struct i > msi_alloc_info_t *info = args; > struct its_device *its_dev = info->scratchpad[0].ptr; > struct its_node *its = its_dev->its; > + struct irq_data *irqd; > irq_hw_number_t hwirq; > int err; > int i; > @@ -3542,7 +3543,9 @@ static int its_irq_domain_alloc(struct i > > irq_domain_set_hwirq_and_chip(domain, virq + i, > hwirq + i, &its_irq_chip, its_dev); > - irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq + i))); > + irqd = irq_get_irq_data(virq + i); > + irqd_set_single_target(irqd); > + irqd_set_affinity_on_activate(irqd); > pr_debug("ID:%d pID:%d vID:%d\n", > (int)(hwirq + i - its_dev->event_map.lpi_base), > (int)(hwirq + i), virq + i); > --- a/include/linux/irq.h > +++ b/include/linux/irq.h > @@ -213,6 +213,8 @@ struct irq_data { > * required > * IRQD_HANDLE_ENFORCE_IRQCTX - Enforce that handle_irq_*() is only invoked > * from actual interrupt context. > + * IRQD_AFFINITY_ON_ACTIVATE - Affinity is set on activation. Don't call > + * irq_chip::irq_set_affinity() when deactivated. > */ > enum { > IRQD_TRIGGER_MASK = 0xf, > @@ -237,6 +239,7 @@ enum { > IRQD_CAN_RESERVE = (1 << 26), > IRQD_MSI_NOMASK_QUIRK = (1 << 27), > IRQD_HANDLE_ENFORCE_IRQCTX = (1 << 28), > + IRQD_AFFINITY_ON_ACTIVATE = (1 << 29), > }; > > #define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors) > @@ -421,6 +424,16 @@ static inline bool irqd_msi_nomask_quirk > return __irqd_to_state(d) & IRQD_MSI_NOMASK_QUIRK; > } > > +static inline void irqd_set_affinity_on_activate(struct irq_data *d) > +{ > + __irqd_to_state(d) |= IRQD_AFFINITY_ON_ACTIVATE; > +} > + > +static inline bool irqd_affinity_on_activate(struct irq_data *d) > +{ > + return __irqd_to_state(d) & IRQD_AFFINITY_ON_ACTIVATE; > +} > + > #undef __irqd_to_state > > static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) > --- a/kernel/irq/manage.c > +++ b/kernel/irq/manage.c > @@ -320,12 +320,16 @@ static bool irq_set_affinity_deactivated > struct irq_desc *desc = irq_data_to_desc(data); > > /* > + * Handle irq chips which can handle affinity only in activated > + * state correctly > + * > * If the interrupt is not yet activated, just store the affinity > * mask and do not call the chip driver at all. On activation the > * driver has to make sure anyway that the interrupt is in a > * useable state so startup works. > */ > - if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) || irqd_is_activated(data)) > + if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) || > + irqd_is_activated(data) || !irqd_affinity_on_activate(data)) > return false; > > cpumask_copy(desc->irq_common_data.affinity, mask); >
I have given this a go on two systems: one with a GICv2 that has its PMUs wired in a similar way to John's system (each CPU PMU is on a separate SPI), and another one that has an ITS. Both came up normally and their interrupts are routed as expected:
* GICv2 PMU: 30: 121 0 0 0 0 0 0 0 GICv2 39 Level arm-pmu 31: 0 167 0 0 0 0 0 0 GICv2 40 Level arm-pmu 32: 0 0 145 0 0 0 0 0 GICv2 41 Level arm-pmu 33: 0 0 0 400 0 0 0 0 GICv2 42 Level arm-pmu 34: 0 0 0 0 97 0 0 0 GICv2 43 Level arm-pmu 35: 0 0 0 0 0 463 0 0 GICv2 44 Level arm-pmu 36: 0 0 0 0 0 0 74 0 GICv2 45 Level arm-pmu 37: 0 0 0 0 0 0 0 8 GICv2 46 Level arm-pmu
* GICv3+ITS: 241: 219 0 0 0 0 0 ITS-MSI 524289 Edge nvme0q1 242: 0 251 0 0 0 0 ITS-MSI 524290 Edge nvme0q2 243: 0 0 197 0 0 0 ITS-MSI 524291 Edge nvme0q3 244: 0 0 0 380 0 0 ITS-MSI 524292 Edge nvme0q4 245: 0 0 0 0 675 0 ITS-MSI 524293 Edge nvme0q5 246: 0 0 0 0 0 436 ITS-MSI 524294 Edge nvme0q6
For a good measure, I've added this on top, adding the missing bits to the debugfs entries:
diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c index 4f9f844074db..d44fc8a5dab2 100644 --- a/kernel/irq/debugfs.c +++ b/kernel/irq/debugfs.c @@ -120,6 +120,9 @@ static const struct irq_bit_descr irqdata_states[] = { BIT_MASK_DESCR(IRQD_WAKEUP_STATE), BIT_MASK_DESCR(IRQD_WAKEUP_ARMED), + BIT_MASK_DESCR(IRQD_DEFAULT_TRIGGER_SET), + BIT_MASK_DESCR(IRQD_HANDLE_ENFORCE_IRQCTX), + BIT_MASK_DESCR(IRQD_AFFINITY_ON_ACTIVATE), }; static const struct irq_bit_descr irqdesc_states[] = { FWIW:
Acked-by: Marc Zyngier <maz@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org>
M.
-- Without deviation from the norm, progress is not possible.
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