linux/kernel/irq
Thomas Gleixner f0c7baca18 genirq/affinity: Make affinity setting if activated opt-in
John reported that on a RK3288 system the perf per CPU interrupts are all
affine to CPU0 and provided the analysis:

 "It looks like what happens is that because the interrupts are not per-CPU
  in the hardware, armpmu_request_irq() calls irq_force_affinity() while
  the interrupt is deactivated and then request_irq() with IRQF_PERCPU |
  IRQF_NOBALANCING.  

  Now when irq_startup() runs with IRQ_STARTUP_NORMAL, it calls
  irq_setup_affinity() which returns early because IRQF_PERCPU and
  IRQF_NOBALANCING are set, leaving the interrupt on its original CPU."

This was broken by the recent commit which blocked interrupt affinity
setting in hardware before activation of the interrupt. While this works in
general, it does not work for this particular case. As contrary to the
initial analysis not all interrupt chip drivers implement an activate
callback, the safe cure is to make the deferred interrupt affinity setting
at activation time opt-in.

Implement the necessary core logic and make the two irqchip implementations
for which this is required opt-in. In hindsight this would have been the
right thing to do, but ...

Fixes: baedb87d1b ("genirq/affinity: Handle affinity setting on inactive interrupts correctly")
Reported-by: John Keeping <john@metanate.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/87blk4tzgm.fsf@nanos.tec.linutronix.de
2020-07-27 16:20:40 +02:00
..
affinity.c genirq/affinity: Remove const qualifier from node_to_cpumask argument 2019-08-28 12:20:43 +02:00
autoprobe.c genirq: Delay deactivation in free_irq() 2019-07-03 10:12:28 +02:00
chip.c genirq: Provide interrupt injection mechanism 2020-03-08 11:06:42 +01:00
cpuhotplug.c genirq, sched/isolation: Isolate from handling managed interrupts 2020-01-22 16:29:49 +01:00
debug.h Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
debugfs.c genirq: Provide interrupt injection mechanism 2020-03-08 11:06:42 +01:00
devres.c genirq/devres: Use struct_size() in devm_kzalloc() 2019-04-16 21:54:03 +02:00
dummychip.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
generic-chip.c genirq: Add missing SPDX identifiers 2018-03-20 14:23:28 +01:00
handle.c x86 entry code updates: 2020-03-30 19:14:28 -07:00
internals.h genirq: Provide interrupt injection mechanism 2020-03-08 11:06:42 +01:00
ipi.c genirq: Fix various typos in comments 2018-12-18 14:22:28 +01:00
irq_sim.c genirq/irq_sim: Simplify the API 2020-05-18 10:30:21 +01:00
irqdesc.c genirq: Add protection against unsafe usage of generic_handle_irq() 2020-03-08 11:06:40 +01:00
irqdomain.c irqdomain: Allow software nodes for IRQ domain creation 2020-05-21 10:53:17 +01:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile genirq/timings: Add selftest for circular array 2019-06-12 10:47:04 +02:00
manage.c genirq/affinity: Make affinity setting if activated opt-in 2020-07-27 16:20:40 +02:00
matrix.c genirq/matrix: Improve target CPU selection for managed interrupts. 2018-11-06 23:20:13 +01:00
migration.c genirq/migration: Avoid out of line call if pending is not set 2018-06-06 15:18:20 +02:00
msi.c x86/apic/msi: Plug non-maskable MSI affinity race 2020-02-01 09:31:47 +01:00
pm.c PCI: irq: Introduce rearm_wake_irq() 2019-07-23 09:37:51 +02:00
proc.c genirq/proc: Reject invalid affinity masks (again) 2020-02-14 09:43:17 +01:00
resend.c genirq: Provide interrupt injection mechanism 2020-03-08 11:06:42 +01:00
settings.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
spurious.c genirq: Add missing __must_hold() sparse annotation 2020-01-09 18:03:37 +01:00
timings.c genirq/timings: Add selftest for next event computation 2019-06-12 10:47:05 +02:00