x86/ioapic: Force affinity setup before startup

The IO/APIC cannot handle interrupt affinity changes safely after startup
other than from an interrupt handler. The startup sequence in the generic
interrupt code violates that assumption.

Mark the irq chip with the new IRQCHIP_AFFINITY_PRE_STARTUP flag so that
the default interrupt setting happens before the interrupt is started up
for the first time.

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/20210729222542.832143400@linutronix.de

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index d5c691a3208b69d7aba5b2321074d6175dab2dd4..39224e035e47569ac7edbf619a5b4ce17a879ec5 100644 (file)
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1986,7 +1986,8 @@ static struct irq_chip ioapic_chip __read_mostly = {
        .irq_set_affinity       = ioapic_set_affinity,
        .irq_retrigger          = irq_chip_retrigger_hierarchy,
        .irq_get_irqchip_state  = ioapic_irq_get_chip_state,
-       .flags                  = IRQCHIP_SKIP_SET_WAKE,
+       .flags                  = IRQCHIP_SKIP_SET_WAKE |
+                                 IRQCHIP_AFFINITY_PRE_STARTUP,
 };
 
 static struct irq_chip ioapic_ir_chip __read_mostly = {
@@ -1999,7 +2000,8 @@ static struct irq_chip ioapic_ir_chip __read_mostly = {
        .irq_set_affinity       = ioapic_set_affinity,
        .irq_retrigger          = irq_chip_retrigger_hierarchy,
        .irq_get_irqchip_state  = ioapic_irq_get_chip_state,
-       .flags                  = IRQCHIP_SKIP_SET_WAKE,
+       .flags                  = IRQCHIP_SKIP_SET_WAKE |
+                                 IRQCHIP_AFFINITY_PRE_STARTUP,
 };
 
 static inline void init_IO_APIC_traps(void)