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  */
18 bool 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 
38 void 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 
48 void 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 
104 void __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 
131 bool 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 }
140