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-rw-r--r--kernel/irq/migration.c119
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..def48589e
--- /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 descpriptor 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);
+}