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authorThomas Gleixner <tglx@linutronix.de>2020-07-17 19:00:02 +0300
committerThomas Gleixner <tglx@linutronix.de>2020-07-18 00:30:43 +0300
commitbaedb87d1b53532f81b4bd0387f83b05d4f7eb9a (patch)
treeaae265599b93bf83078c58e5e1be6b35cd0bff8b /arch/x86/kernel/apic
parente3beca48a45b5e0e6e6a4e0124276b8248dcc9bb (diff)
downloadlinux-baedb87d1b53532f81b4bd0387f83b05d4f7eb9a.tar.xz
genirq/affinity: Handle affinity setting on inactive interrupts correctly
Setting interrupt affinity on inactive interrupts is inconsistent when hierarchical irq domains are enabled. The core code should just store the affinity and not call into the irq chip driver for inactive interrupts because the chip drivers may not be in a state to handle such requests. X86 has a hacky workaround for that but all other irq chips have not which causes problems e.g. on GIC V3 ITS. Instead of adding more ugly hacks all over the place, solve the problem in the core code. If the affinity is set on an inactive interrupt then: - Store it in the irq descriptors affinity mask - Update the effective affinity to reflect that so user space has a consistent view - Don't call into the irq chip driver This is the core equivalent of the X86 workaround and works correctly because the affinity setting is established in the irq chip when the interrupt is activated later on. Note, that this is only effective when hierarchical irq domains are enabled by the architecture. Doing it unconditionally would break legacy irq chip implementations. For hierarchial irq domains this works correctly as none of the drivers can have a dependency on affinity setting in inactive state by design. Remove the X86 workaround as it is not longer required. Fixes: 02edee152d6e ("x86/apic/vector: Ignore set_affinity call for inactive interrupts") Reported-by: Ali Saidi <alisaidi@amazon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Ali Saidi <alisaidi@amazon.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200529015501.15771-1-alisaidi@amazon.com Link: https://lkml.kernel.org/r/877dv2rv25.fsf@nanos.tec.linutronix.de
Diffstat (limited to 'arch/x86/kernel/apic')
-rw-r--r--arch/x86/kernel/apic/vector.c22
1 files changed, 5 insertions, 17 deletions
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index cc8b16f89dd4..7649da2478d8 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -446,12 +446,10 @@ static int x86_vector_activate(struct irq_domain *dom, struct irq_data *irqd,
trace_vector_activate(irqd->irq, apicd->is_managed,
apicd->can_reserve, reserve);
- /* Nothing to do for fixed assigned vectors */
- if (!apicd->can_reserve && !apicd->is_managed)
- return 0;
-
raw_spin_lock_irqsave(&vector_lock, flags);
- if (reserve || irqd_is_managed_and_shutdown(irqd))
+ if (!apicd->can_reserve && !apicd->is_managed)
+ assign_irq_vector_any_locked(irqd);
+ else if (reserve || irqd_is_managed_and_shutdown(irqd))
vector_assign_managed_shutdown(irqd);
else if (apicd->is_managed)
ret = activate_managed(irqd);
@@ -774,20 +772,10 @@ void lapic_offline(void)
static int apic_set_affinity(struct irq_data *irqd,
const struct cpumask *dest, bool force)
{
- struct apic_chip_data *apicd = apic_chip_data(irqd);
int err;
- /*
- * Core code can call here for inactive interrupts. For inactive
- * interrupts which use managed or reservation mode there is no
- * point in going through the vector assignment right now as the
- * activation will assign a vector which fits the destination
- * cpumask. Let the core code store the destination mask and be
- * done with it.
- */
- if (!irqd_is_activated(irqd) &&
- (apicd->is_managed || apicd->can_reserve))
- return IRQ_SET_MASK_OK;
+ if (WARN_ON_ONCE(!irqd_is_activated(irqd)))
+ return -EIO;
raw_spin_lock(&vector_lock);
cpumask_and(vector_searchmask, dest, cpu_online_mask);