x86/ioapic: Force affinity setting in setup_ioapic_dest()

KAGA-KOKO · KAGA-KOKO · commit 4857c91f0d19 · 2015-09-14T18:28:15.000+02:00
The recent ioapic cleanups changed the affinity setting in setup_ioapic_dest() from a direct write to the hardware to the delayed affinity setup via irq_set_affinity(). That results in a warning from chained_irq_exit(): WARNING: CPU: 0 PID: 5 at kernel/irq/migration.c:32 irq_move_masked_irq [<ffffffff810a0a88>] irq_move_masked_irq+0xb8/0xc0 [<ffffffff8103c161>] ioapic_ack_level+0x111/0x130 [<ffffffff812bbfe8>] intel_gpio_irq_handler+0x148/0x1c0 The reason is that irq_set_affinity() does not write directly to the hardware. It marks the affinity setting as pending and executes it from the next interrupt. The chained handler infrastructure does not take the irq descriptor lock for performance reasons because such a chained interrupt is not visible to any interfaces. So the delayed affinity setting triggers the warning in irq_move_masked_irq(). Restore the old behaviour by calling the set_affinity function of the ioapic chip in setup_ioapic_dest(). This is safe as none of the interrupts can be on the fly at this point. Fixes: aa5cb97 'x86/irq: Remove x86_io_apic_ops.set_affinity and related interfaces' Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: jarkko.nikula@linux.intel.com
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
@@ -2522,6 +2522,7 @@ void __init setup_ioapic_dest(void)
 	int pin, ioapic, irq, irq_entry;
 	const struct cpumask *mask;
 	struct irq_data *idata;
+	struct irq_chip *chip;
 
 	if (skip_ioapic_setup == 1)
 		return;
@@ -2545,9 +2546,9 @@ void __init setup_ioapic_dest(void)
 		else
 			mask = apic->target_cpus();
 
-		irq_set_affinity(irq, mask);
+		chip = irq_data_get_irq_chip(idata);
+		chip->irq_set_affinity(idata, mask, false);
 	}
-
 }
 #endif
 
