diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-07-24 22:44:41 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-21 13:05:20 +0200 |
| commit | a11f42496ac80813d94b30d51868d4610bb5e5d9 (patch) | |
| tree | 6e52680cb3d19d15ddca7aa34f42f29cacbb3455 /include | |
| parent | 582ee2cb6f905d5d3eaccfeda7adbbd4d782397b (diff) | |
genirq/affinity: Make affinity setting if activated opt-in
commit f0c7baca180046824e07fc5f1326e83a8fd150c7 upstream.
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: baedb87d1b53 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/irq.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h index f8755e5fcd74..e9e69c511ea9 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -211,6 +211,8 @@ struct irq_data { * IRQD_CAN_RESERVE - Can use reservation mode * IRQD_MSI_NOMASK_QUIRK - Non-maskable MSI quirk for affinity change * required + * IRQD_AFFINITY_ON_ACTIVATE - Affinity is set on activation. Don't call + * irq_chip::irq_set_affinity() when deactivated. */ enum { IRQD_TRIGGER_MASK = 0xf, @@ -234,6 +236,7 @@ enum { IRQD_DEFAULT_TRIGGER_SET = (1 << 25), IRQD_CAN_RESERVE = (1 << 26), IRQD_MSI_NOMASK_QUIRK = (1 << 27), + IRQD_AFFINITY_ON_ACTIVATE = (1 << 29), }; #define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors) @@ -408,6 +411,16 @@ static inline bool irqd_msi_nomask_quirk(struct irq_data *d) 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) |