John,
Thomas Gleixner <t...@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);
