migration.c

  1// SPDX-License-Identifier: GPL-2.0
  2
  3#include <linux/irq.h>
  4#include <linux/interrupt.h>
  5
  6#include "internals.h"
  7
  8/**
  9 * irq_fixup_move_pending - Cleanup irq move pending from a dying CPU
 10 * @desc:		Interrupt descriptor to clean up
 11 * @force_clear:	If set clear the move pending bit unconditionally.
 12 *			If not set, clear it only when the dying CPU is the
 13 *			last one in the pending mask.
 14 *
 15 * Returns true if the pending bit was set and the pending mask contains an
 16 * online CPU other than the dying CPU.
 17 */
 18bool irq_fixup_move_pending(struct irq_desc *desc, bool force_clear)
 19{
 20	struct irq_data *data = irq_desc_get_irq_data(desc);
 21
 22	if (!irqd_is_setaffinity_pending(data))
 23		return false;
 24
 25	/*
 26	 * The outgoing CPU might be the last online target in a pending
 27	 * interrupt move. If that's the case clear the pending move bit.
 28	 */
 29	if (!cpumask_intersects(desc->pending_mask, cpu_online_mask)) {
 30		irqd_clr_move_pending(data);
 31		return false;
 32	}
 33	if (force_clear)
 34		irqd_clr_move_pending(data);
 35	return true;
 36}
 37
 38void irq_force_complete_move(struct irq_desc *desc)
 39{
 40	for (struct irq_data *d = irq_desc_get_irq_data(desc); d; d = irqd_get_parent_data(d)) {
 41		if (d->chip && d->chip->irq_force_complete_move) {
 42			d->chip->irq_force_complete_move(d);
 43			return;
 44		}
 45	}
 46}
 47
 48void irq_move_masked_irq(struct irq_data *idata)
 49{
 50	struct irq_desc *desc = irq_data_to_desc(idata);
 51	struct irq_data *data = &desc->irq_data;
 52	struct irq_chip *chip = data->chip;
 53
 54	if (likely(!irqd_is_setaffinity_pending(data)))
 55		return;
 56
 57	irqd_clr_move_pending(data);
 58
 59	/*
 60	 * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
 61	 */
 62	if (irqd_is_per_cpu(data)) {
 63		WARN_ON(1);
 64		return;
 65	}
 66
 67	if (unlikely(cpumask_empty(desc->pending_mask)))
 68		return;
 69
 70	if (!chip->irq_set_affinity)
 71		return;
 72
 73	assert_raw_spin_locked(&desc->lock);
 74
 75	/*
 76	 * If there was a valid mask to work with, please
 77	 * do the disable, re-program, enable sequence.
 78	 * This is *not* particularly important for level triggered
 79	 * but in a edge trigger case, we might be setting rte
 80	 * when an active trigger is coming in. This could
 81	 * cause some ioapics to mal-function.
 82	 * Being paranoid i guess!
 83	 *
 84	 * For correct operation this depends on the caller
 85	 * masking the irqs.
 86	 */
 87	if (cpumask_intersects(desc->pending_mask, cpu_online_mask)) {
 88		int ret;
 89
 90		ret = irq_do_set_affinity(data, desc->pending_mask, false);
 91		/*
 92		 * If the there is a cleanup pending in the underlying
 93		 * vector management, reschedule the move for the next
 94		 * interrupt. Leave desc->pending_mask intact.
 95		 */
 96		if (ret == -EBUSY) {
 97			irqd_set_move_pending(data);
 98			return;
 99		}
100	}
101	cpumask_clear(desc->pending_mask);
102}
103
104void __irq_move_irq(struct irq_data *idata)
105{
106	bool masked;
107
108	/*
109	 * Get top level irq_data when CONFIG_IRQ_DOMAIN_HIERARCHY is enabled,
110	 * and it should be optimized away when CONFIG_IRQ_DOMAIN_HIERARCHY is
111	 * disabled. So we avoid an "#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY" here.
112	 */
113	idata = irq_desc_get_irq_data(irq_data_to_desc(idata));
114
115	if (unlikely(irqd_irq_disabled(idata)))
116		return;
117
118	/*
119	 * Be careful vs. already masked interrupts. If this is a
120	 * threaded interrupt with ONESHOT set, we can end up with an
121	 * interrupt storm.
122	 */
123	masked = irqd_irq_masked(idata);
124	if (!masked)
125		idata->chip->irq_mask(idata);
126	irq_move_masked_irq(idata);
127	if (!masked)
128		idata->chip->irq_unmask(idata);
129}
130
131bool irq_can_move_in_process_context(struct irq_data *data)
132{
133	/*
134	 * Get the top level irq_data in the hierarchy, which is optimized
135	 * away when CONFIG_IRQ_DOMAIN_HIERARCHY is disabled.
136	 */
137	data = irq_desc_get_irq_data(irq_data_to_desc(data));
138	return irq_can_move_pcntxt(data);
139}