1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
* Copyright (C) 2005-2006, Thomas Gleixner
*
* This file contains the IRQ-resend code
*
* If the interrupt is waiting to be processed, we try to re-run it.
* We can't directly run it from here since the caller might be in an
* interrupt-protected region. Not all irq controller chips can
* retrigger interrupts at the hardware level, so in those cases
* we allow the resending of IRQs via a tasklet.
*/
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
#include "internals.h"
#ifdef CONFIG_HARDIRQS_SW_RESEND
/* Bitmap to handle software resend of interrupts: */
static DECLARE_BITMAP(irqs_resend, IRQ_BITMAP_BITS);
/*
* Run software resends of IRQ's
*/
static void resend_irqs(unsigned long arg)
{
struct irq_desc *desc;
int irq;
while (!bitmap_empty(irqs_resend, nr_irqs)) {
irq = find_first_bit(irqs_resend, nr_irqs);
clear_bit(irq, irqs_resend);
desc = irq_to_desc(irq);
if (!desc)
continue;
local_irq_disable();
desc->handle_irq(desc);
local_irq_enable();
}
}
/* Tasklet to handle resend: */
static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
static int irq_sw_resend(struct irq_desc *desc)
{
unsigned int irq = irq_desc_get_irq(desc);
/*
* Validate whether this interrupt can be safely injected from
* non interrupt context
*/
if (handle_enforce_irqctx(&desc->irq_data))
return -EINVAL;
/*
* If the interrupt is running in the thread context of the parent
* irq we need to be careful, because we cannot trigger it
* directly.
*/
if (irq_settings_is_nested_thread(desc)) {
/*
* If the parent_irq is valid, we retrigger the parent,
* otherwise we do nothing.
*/
if (!desc->parent_irq)
return -EINVAL;
irq = desc->parent_irq;
}
/* Set it pending and activate the softirq: */
set_bit(irq, irqs_resend);
tasklet_schedule(&resend_tasklet);
return 0;
}
#else
static int irq_sw_resend(struct irq_desc *desc)
{
return -EINVAL;
}
#endif
/*
* IRQ resend
*
* Is called with interrupts disabled and desc->lock held.
*/
int check_irq_resend(struct irq_desc *desc)
{
/*
* We do not resend level type interrupts. Level type interrupts
* are resent by hardware when they are still active. Clear the
* pending bit so suspend/resume does not get confused.
*/
if (irq_settings_is_level(desc)) {
desc->istate &= ~IRQS_PENDING;
return -EINVAL;
}
if (desc->istate & IRQS_REPLAY)
return -EBUSY;
if (desc->istate & IRQS_PENDING) {
desc->istate &= ~IRQS_PENDING;
desc->istate |= IRQS_REPLAY;
if (!desc->irq_data.chip->irq_retrigger ||
!desc->irq_data.chip->irq_retrigger(&desc->irq_data))
return irq_sw_resend(desc);
}
return 0;
}
|
