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genirq: Provide IRQCHIP_AFFINITY_PRE_STARTUP 

commit 826da771291fc25a428e871f9e7fb465e390f852 upstream.

X86 IO/APIC and MSI interrupts (when used without interrupts remapping)
require that the affinity setup on startup is done before the interrupt is
enabled for the first time as the non-remapped operation mode cannot safely
migrate enabled interrupts from arbitrary contexts. Provide a new irq chip
flag which allows affected hardware to request this.

This has to be opt-in because there have been reports in the past that some
interrupt chips cannot handle affinity setting before startup.

Fixes: 1840475676 ("genirq: Expose default irq affinity mask (take 3)")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.779791738@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thomas Gleixner 2021-07-29 23:51:48 +02:00 committed by Greg Kroah-Hartman
parent 06b3477436
commit eda32c2188
2 changed files with 6 additions and 1 deletions
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2
include/linux/irq.h
View File

@ -542,6 +542,7 @@ struct irq_chip {
* IRQCHIP_EOI_THREADED: Chip requires eoi() on unmask in threaded mode
* IRQCHIP_SUPPORTS_LEVEL_MSI Chip can provide two doorbells for Level MSIs
* IRQCHIP_SUPPORTS_NMI: Chip can deliver NMIs, only for root irqchips
* IRQCHIP_AFFINITY_PRE_STARTUP: Default affinity update before startup
*/
enum {
IRQCHIP_SET_TYPE_MASKED = (1 << 0),
@ -553,6 +554,7 @@ enum {
IRQCHIP_EOI_THREADED = (1 << 6),
IRQCHIP_SUPPORTS_LEVEL_MSI = (1 << 7),
IRQCHIP_SUPPORTS_NMI = (1 << 8),
IRQCHIP_AFFINITY_PRE_STARTUP = (1 << 10),
};
#include <linux/irqdesc.h>

5
kernel/irq/chip.c
View File

@ -265,8 +265,11 @@ int irq_startup(struct irq_desc *desc, bool resend, bool force)
} else {
switch (__irq_startup_managed(desc, aff, force)) {
case IRQ_STARTUP_NORMAL:
if (d->chip->flags & IRQCHIP_AFFINITY_PRE_STARTUP)
irq_setup_affinity(desc);
ret = __irq_startup(desc);
irq_setup_affinity(desc);
if (!(d->chip->flags & IRQCHIP_AFFINITY_PRE_STARTUP))
irq_setup_affinity(desc);
break;
case IRQ_STARTUP_MANAGED:
irq_do_set_affinity(d, aff, false);