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authorThomas Gleixner <tglx@linutronix.de>2021-07-29 23:51:48 +0200
committerThomas Gleixner <tglx@linutronix.de>2021-08-10 10:59:20 +0200
commit826da771291fc25a428e871f9e7fb465e390f852 (patch)
treed5675ccc63c138913774d52f644dd5a962bcb2e5
parent77e89afc25f30abd56e76a809ee2884d7c1b63ce (diff)
downloadlinux-826da771291fc25a428e871f9e7fb465e390f852.tar.bz2
genirq: Provide IRQCHIP_AFFINITY_PRE_STARTUP
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: 18404756765c ("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
-rw-r--r--include/linux/irq.h2
-rw-r--r--kernel/irq/chip.c5
2 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 8e9a9ae471a6..c8293c817646 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -569,6 +569,7 @@ struct irq_chip {
* IRQCHIP_SUPPORTS_NMI: Chip can deliver NMIs, only for root irqchips
* IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND: Invokes __enable_irq()/__disable_irq() for wake irqs
* in the suspend path if they are in disabled state
+ * IRQCHIP_AFFINITY_PRE_STARTUP: Default affinity update before startup
*/
enum {
IRQCHIP_SET_TYPE_MASKED = (1 << 0),
@@ -581,6 +582,7 @@ enum {
IRQCHIP_SUPPORTS_LEVEL_MSI = (1 << 7),
IRQCHIP_SUPPORTS_NMI = (1 << 8),
IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND = (1 << 9),
+ IRQCHIP_AFFINITY_PRE_STARTUP = (1 << 10),
};
#include <linux/irqdesc.h>
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 7f04c7d8296e..a98bcfc4be7b 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -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);