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 descpriptor 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 */
irq_fixup_move_pending(struct irq_desc * desc,bool force_clear)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_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
irq_move_masked_irq(struct irq_data * idata)38 void 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
__irq_move_irq(struct irq_data * idata)94 void __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