1 files changed, 119 insertions, 0 deletions
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
new file mode 100644
index 000000000..61ca924ef
--- /dev/null
+++ b/kernel/irq/migration.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+
+#include "internals.h"
+
+/**
+ * irq_fixup_move_pending - Cleanup irq move pending from a dying CPU
+ * @desc:		Interrupt descriptor to clean up
+ * @force_clear:	If set clear the move pending bit unconditionally.
+ *			If not set, clear it only when the dying CPU is the
+ *			last one in the pending mask.
+ *
+ * Returns true if the pending bit was set and the pending mask contains an
+ * online CPU other than the dying CPU.
+ */
+bool irq_fixup_move_pending(struct irq_desc *desc, bool force_clear)
+{
+	struct irq_data *data = irq_desc_get_irq_data(desc);
+
+	if (!irqd_is_setaffinity_pending(data))
+		return false;
+
+	/*
+	 * The outgoing CPU might be the last online target in a pending
+	 * interrupt move. If that's the case clear the pending move bit.
+	 */
+	if (cpumask_any_and(desc->pending_mask, cpu_online_mask) >= nr_cpu_ids) {
+		irqd_clr_move_pending(data);
+		return false;
+	}
+	if (force_clear)
+		irqd_clr_move_pending(data);
+	return true;
+}
+
+void irq_move_masked_irq(struct irq_data *idata)
+{
+	struct irq_desc *desc = irq_data_to_desc(idata);
+	struct irq_data *data = &desc->irq_data;
+	struct irq_chip *chip = data->chip;
+
+	if (likely(!irqd_is_setaffinity_pending(data)))
+		return;
+
+	irqd_clr_move_pending(data);
+
+	/*
+	 * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
+	 */
+	if (irqd_is_per_cpu(data)) {
+		WARN_ON(1);
+		return;
+	}
+
+	if (unlikely(cpumask_empty(desc->pending_mask)))
+		return;
+
+	if (!chip->irq_set_affinity)
+		return;
+
+	assert_raw_spin_locked(&desc->lock);
+
+	/*
+	 * If there was a valid mask to work with, please
+	 * do the disable, re-program, enable sequence.
+	 * This is *not* particularly important for level triggered
+	 * but in a edge trigger case, we might be setting rte
+	 * when an active trigger is coming in. This could
+	 * cause some ioapics to mal-function.
+	 * Being paranoid i guess!
+	 *
+	 * For correct operation this depends on the caller
+	 * masking the irqs.
+	 */
+	if (cpumask_any_and(desc->pending_mask, cpu_online_mask) < nr_cpu_ids) {
+		int ret;
+
+		ret = irq_do_set_affinity(data, desc->pending_mask, false);
+		/*
+		 * If the there is a cleanup pending in the underlying
+		 * vector management, reschedule the move for the next
+		 * interrupt. Leave desc->pending_mask intact.
+		 */
+		if (ret == -EBUSY) {
+			irqd_set_move_pending(data);
+			return;
+		}
+	}
+	cpumask_clear(desc->pending_mask);
+}
+
+void __irq_move_irq(struct irq_data *idata)
+{
+	bool masked;
+
+	/*
+	 * Get top level irq_data when CONFIG_IRQ_DOMAIN_HIERARCHY is enabled,
+	 * and it should be optimized away when CONFIG_IRQ_DOMAIN_HIERARCHY is
+	 * disabled. So we avoid an "#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY" here.
+	 */
+	idata = irq_desc_get_irq_data(irq_data_to_desc(idata));
+
+	if (unlikely(irqd_irq_disabled(idata)))
+		return;
+
+	/*
+	 * Be careful vs. already masked interrupts. If this is a
+	 * threaded interrupt with ONESHOT set, we can end up with an
+	 * interrupt storm.
+	 */
+	masked = irqd_irq_masked(idata);
+	if (!masked)
+		idata->chip->irq_mask(idata);
+	irq_move_masked_irq(idata);
+	if (!masked)
+		idata->chip->irq_unmask(idata);
+}