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_any_and(desc->pending_mask, cpu_online_mask) >= nr_cpu_ids) {
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_move_masked_irq(struct irq_data *idata)
39{
40	struct irq_desc *desc = irq_data_to_desc(idata);
41	struct irq_data *data = &desc->irq_data;
42	struct irq_chip *chip = data->chip;
43
44	if (likely(!irqd_is_setaffinity_pending(data)))
45		return;
46
47	irqd_clr_move_pending(data);
48
49	/*
50	 * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
51	 */
52	if (irqd_is_per_cpu(data)) {
53		WARN_ON(1);
54		return;
55	}
56
57	if (unlikely(cpumask_empty(desc->pending_mask)))
58		return;
59
60	if (!chip->irq_set_affinity)
61		return;
62
63	assert_raw_spin_locked(&desc->lock);
64
65	/*
66	 * If there was a valid mask to work with, please
67	 * do the disable, re-program, enable sequence.
68	 * This is *not* particularly important for level triggered
69	 * but in a edge trigger case, we might be setting rte
70	 * when an active trigger is coming in. This could
71	 * cause some ioapics to mal-function.
72	 * Being paranoid i guess!
73	 *
74	 * For correct operation this depends on the caller
75	 * masking the irqs.
76	 */
77	if (cpumask_any_and(desc->pending_mask, cpu_online_mask) < nr_cpu_ids) {
78		int ret;
79
80		ret = irq_do_set_affinity(data, desc->pending_mask, false);
81		/*
82		 * If the there is a cleanup pending in the underlying
83		 * vector management, reschedule the move for the next
84		 * interrupt. Leave desc->pending_mask intact.
85		 */
86		if (ret == -EBUSY) {
87			irqd_set_move_pending(data);
88			return;
89		}
90	}
91	cpumask_clear(desc->pending_mask);
92}
93
94void __irq_move_irq(struct irq_data *idata)
95{
96	bool masked;
97
98	/*
99	 * Get top level irq_data when CONFIG_IRQ_DOMAIN_HIERARCHY is enabled,
100	 * and it should be optimized away when CONFIG_IRQ_DOMAIN_HIERARCHY is
101	 * disabled. So we avoid an "#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY" here.
102	 */
103	idata = irq_desc_get_irq_data(irq_data_to_desc(idata));
104
105	if (unlikely(irqd_irq_disabled(idata)))
106		return;
107
108	/*
109	 * Be careful vs. already masked interrupts. If this is a
110	 * threaded interrupt with ONESHOT set, we can end up with an
111	 * interrupt storm.
112	 */
113	masked = irqd_irq_masked(idata);
114	if (!masked)
115		idata->chip->irq_mask(idata);
116	irq_move_masked_irq(idata);
117	if (!masked)
118		idata->chip->irq_unmask(idata);
119}
120