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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/irq.c | |
3 | * | |
4 | * Copyright (C) 1992 Linus Torvalds | |
5 | * Modifications for ARM processor Copyright (C) 1995-2000 Russell King. | |
6 | * | |
8749af68 RK |
7 | * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation. |
8 | * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and | |
9 | * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>. | |
10 | * | |
1da177e4 LT |
11 | * This program is free software; you can redistribute it and/or modify |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * published by the Free Software Foundation. | |
14 | * | |
15 | * This file contains the code used by various IRQ handling routines: | |
16 | * asking for different IRQ's should be done through these routines | |
17 | * instead of just grabbing them. Thus setups with different IRQ numbers | |
18 | * shouldn't result in any weird surprises, and installing new handlers | |
19 | * should be easier. | |
20 | * | |
21 | * IRQ's are in fact implemented a bit like signal handlers for the kernel. | |
22 | * Naturally it's not a 1:1 relation, but there are similarities. | |
23 | */ | |
1da177e4 LT |
24 | #include <linux/kernel_stat.h> |
25 | #include <linux/module.h> | |
26 | #include <linux/signal.h> | |
27 | #include <linux/ioport.h> | |
28 | #include <linux/interrupt.h> | |
4a2581a0 | 29 | #include <linux/irq.h> |
1da177e4 LT |
30 | #include <linux/random.h> |
31 | #include <linux/smp.h> | |
32 | #include <linux/init.h> | |
33 | #include <linux/seq_file.h> | |
34 | #include <linux/errno.h> | |
35 | #include <linux/list.h> | |
36 | #include <linux/kallsyms.h> | |
37 | #include <linux/proc_fs.h> | |
61b5cb1c | 38 | #include <linux/ftrace.h> |
1da177e4 | 39 | |
1da177e4 | 40 | #include <asm/system.h> |
8ff1443c | 41 | #include <asm/mach/arch.h> |
897d8527 | 42 | #include <asm/mach/irq.h> |
8749af68 | 43 | #include <asm/mach/time.h> |
1da177e4 | 44 | |
1da177e4 LT |
45 | /* |
46 | * No architecture-specific irq_finish function defined in arm/arch/irqs.h. | |
47 | */ | |
48 | #ifndef irq_finish | |
49 | #define irq_finish(irq) do { } while (0) | |
50 | #endif | |
51 | ||
4a2581a0 | 52 | unsigned long irq_err_count; |
1da177e4 | 53 | |
25a5662a | 54 | int arch_show_interrupts(struct seq_file *p, int prec) |
1da177e4 | 55 | { |
baa28e35 | 56 | #ifdef CONFIG_FIQ |
25a5662a | 57 | show_fiq_list(p, prec); |
1da177e4 LT |
58 | #endif |
59 | #ifdef CONFIG_SMP | |
25a5662a | 60 | show_ipi_list(p, prec); |
ec405ea9 RK |
61 | #endif |
62 | #ifdef CONFIG_LOCAL_TIMERS | |
25a5662a | 63 | show_local_irqs(p, prec); |
1da177e4 | 64 | #endif |
25a5662a | 65 | seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); |
1da177e4 LT |
66 | return 0; |
67 | } | |
68 | ||
1da177e4 LT |
69 | /* |
70 | * do_IRQ handles all hardware IRQ's. Decoded IRQs should not | |
71 | * come via this function. Instead, they should provide their | |
72 | * own 'handler' | |
73 | */ | |
61b5cb1c RV |
74 | asmlinkage void __exception_irq_entry |
75 | asm_do_IRQ(unsigned int irq, struct pt_regs *regs) | |
1da177e4 | 76 | { |
e6300155 | 77 | struct pt_regs *old_regs = set_irq_regs(regs); |
d8aa0251 DB |
78 | |
79 | irq_enter(); | |
1da177e4 LT |
80 | |
81 | /* | |
82 | * Some hardware gives randomly wrong interrupts. Rather | |
83 | * than crashing, do something sensible. | |
84 | */ | |
354e6f72 | 85 | if (unlikely(irq >= nr_irqs)) { |
7aa5514e AK |
86 | if (printk_ratelimit()) |
87 | printk(KERN_WARNING "Bad IRQ%u\n", irq); | |
88 | ack_bad_irq(irq); | |
89 | } else { | |
d8aa0251 | 90 | generic_handle_irq(irq); |
7aa5514e | 91 | } |
1da177e4 | 92 | |
4a2581a0 | 93 | /* AT91 specific workaround */ |
1da177e4 LT |
94 | irq_finish(irq); |
95 | ||
1da177e4 | 96 | irq_exit(); |
e6300155 | 97 | set_irq_regs(old_regs); |
1da177e4 LT |
98 | } |
99 | ||
1da177e4 LT |
100 | void set_irq_flags(unsigned int irq, unsigned int iflags) |
101 | { | |
1b7a2d90 | 102 | unsigned long clr = 0, set = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; |
1da177e4 | 103 | |
354e6f72 | 104 | if (irq >= nr_irqs) { |
1da177e4 LT |
105 | printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq); |
106 | return; | |
107 | } | |
108 | ||
4a2581a0 | 109 | if (iflags & IRQF_VALID) |
1b7a2d90 | 110 | clr |= IRQ_NOREQUEST; |
4a2581a0 | 111 | if (iflags & IRQF_PROBE) |
1b7a2d90 | 112 | clr |= IRQ_NOPROBE; |
4a2581a0 | 113 | if (!(iflags & IRQF_NOAUTOEN)) |
1b7a2d90 TG |
114 | clr |= IRQ_NOAUTOEN; |
115 | /* Order is clear bits in "clr" then set bits in "set" */ | |
116 | irq_modify_status(irq, clr, set & ~clr); | |
1da177e4 LT |
117 | } |
118 | ||
119 | void __init init_IRQ(void) | |
120 | { | |
8ff1443c | 121 | machine_desc->init_irq(); |
1da177e4 LT |
122 | } |
123 | ||
354e6f72 | 124 | #ifdef CONFIG_SPARSE_IRQ |
125 | int __init arch_probe_nr_irqs(void) | |
126 | { | |
8ff1443c | 127 | nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS; |
b683de2b | 128 | return nr_irqs; |
354e6f72 | 129 | } |
130 | #endif | |
131 | ||
a054a811 | 132 | #ifdef CONFIG_HOTPLUG_CPU |
f7ede370 | 133 | |
61791244 | 134 | static bool migrate_one_irq(struct irq_data *d) |
f7ede370 | 135 | { |
61791244 RK |
136 | unsigned int cpu = cpumask_any_and(d->affinity, cpu_online_mask); |
137 | bool ret = false; | |
f7ede370 | 138 | |
61791244 RK |
139 | if (cpu >= nr_cpu_ids) { |
140 | cpu = cpumask_any(cpu_online_mask); | |
141 | ret = true; | |
142 | } | |
143 | ||
144 | pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", d->irq, d->node, cpu); | |
145 | ||
146 | d->chip->irq_set_affinity(d, cpumask_of(cpu), true); | |
147 | ||
148 | return ret; | |
f7ede370 TG |
149 | } |
150 | ||
a054a811 RK |
151 | /* |
152 | * The CPU has been marked offline. Migrate IRQs off this CPU. If | |
153 | * the affinity settings do not allow other CPUs, force them onto any | |
154 | * available CPU. | |
155 | */ | |
156 | void migrate_irqs(void) | |
157 | { | |
158 | unsigned int i, cpu = smp_processor_id(); | |
354e6f72 | 159 | struct irq_desc *desc; |
61791244 RK |
160 | unsigned long flags; |
161 | ||
162 | local_irq_save(flags); | |
a054a811 | 163 | |
354e6f72 | 164 | for_each_irq_desc(i, desc) { |
f64305a6 | 165 | struct irq_data *d = &desc->irq_data; |
61791244 | 166 | bool affinity_broken = false; |
f64305a6 | 167 | |
61791244 | 168 | raw_spin_lock(&desc->lock); |
2ef75701 RK |
169 | if (desc->action != NULL && |
170 | cpumask_test_cpu(smp_processor_id(), d->affinity)) | |
61791244 | 171 | affinity_broken = migrate_one_irq(d); |
61791244 RK |
172 | raw_spin_unlock(&desc->lock); |
173 | ||
174 | if (affinity_broken && printk_ratelimit()) | |
175 | pr_warning("IRQ%u no longer affine to CPU%u\n", i, cpu); | |
a054a811 | 176 | } |
61791244 RK |
177 | |
178 | local_irq_restore(flags); | |
a054a811 RK |
179 | } |
180 | #endif /* CONFIG_HOTPLUG_CPU */ |