linux/arch/arm/mach-ux500
Will Deacon a3287c41ff drivers/perf: arm_pmu: Request PMU SPIs with IRQF_PER_CPU
Since the PMU register interface is banked per CPU, CPU PMU interrrupts
cannot be handled by a CPU other than the one with the PMU asserting the
interrupt. This means that migrating PMU SPIs, as we do during a CPU
hotplug operation doesn't make any sense and can lead to the IRQ being
disabled entirely if we route a spurious IRQ to the new affinity target.

This has been observed in practice on AMD Seattle, where CPUs on the
non-boot cluster appear to take a spurious PMU IRQ when coming online,
which is routed to CPU0 where it cannot be handled.

This patch passes IRQF_PERCPU for PMU SPIs and forcefully sets their
affinity prior to requesting them, ensuring that they cannot
be migrated during hotplug events. This interacts badly with the DB8500
erratum workaround that ping-pongs the interrupt affinity from the handler,
so we avoid passing IRQF_PERCPU in that case by allowing the IRQ flags
to be overridden in the platdata.

Fixes: 3cf7ee98b8 ("drivers/perf: arm_pmu: move irq request/free into probe")
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-07-27 13:43:22 +01:00
..
Kconfig ARM: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB 2016-06-03 12:18:13 -07:00
Makefile ARM: ux500: resume the second core properly 2017-03-02 17:53:17 +01:00
cpu-db8500.c drivers/perf: arm_pmu: Request PMU SPIs with IRQF_PER_CPU 2017-07-27 13:43:22 +01:00
db8500-regs.h ARM: ux500: avoid warning in ux500_read_asicid 2013-06-04 11:21:58 +02:00
platsmp.c ARM: SoC: late DT updates for v4.11 2017-03-03 16:15:48 -08:00
pm.c ARM: ux500: fix prcmu_is_cpu_in_wfi() calculation 2017-01-12 13:25:39 +01:00
pm_domains.c ARM: make of_device_ids const 2015-02-19 09:44:25 +01:00
pm_domains.h ARM: ux500: Initial support for PM domains 2014-10-28 10:48:23 +01:00