[ARM] 5298/1: Drop desc_handle_irq()
[linux-2.6.git] / arch / arm / kernel / irq.c
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  *
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  *
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  */
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>
29 #include <linux/irq.h>
30 #include <linux/slab.h>
31 #include <linux/random.h>
32 #include <linux/smp.h>
33 #include <linux/init.h>
34 #include <linux/seq_file.h>
35 #include <linux/errno.h>
36 #include <linux/list.h>
37 #include <linux/kallsyms.h>
38 #include <linux/proc_fs.h>
39
40 #include <asm/system.h>
41 #include <asm/mach/irq.h>
42 #include <asm/mach/time.h>
43
44 /*
45  * No architecture-specific irq_finish function defined in arm/arch/irqs.h.
46  */
47 #ifndef irq_finish
48 #define irq_finish(irq) do { } while (0)
49 #endif
50
51 void (*init_arch_irq)(void) __initdata = NULL;
52 unsigned long irq_err_count;
53
54 int show_interrupts(struct seq_file *p, void *v)
55 {
56         int i = *(loff_t *) v, cpu;
57         struct irqaction * action;
58         unsigned long flags;
59
60         if (i == 0) {
61                 char cpuname[12];
62
63                 seq_printf(p, "    ");
64                 for_each_present_cpu(cpu) {
65                         sprintf(cpuname, "CPU%d", cpu);
66                         seq_printf(p, " %10s", cpuname);
67                 }
68                 seq_putc(p, '\n');
69         }
70
71         if (i < NR_IRQS) {
72                 spin_lock_irqsave(&irq_desc[i].lock, flags);
73                 action = irq_desc[i].action;
74                 if (!action)
75                         goto unlock;
76
77                 seq_printf(p, "%3d: ", i);
78                 for_each_present_cpu(cpu)
79                         seq_printf(p, "%10u ", kstat_cpu(cpu).irqs[i]);
80                 seq_printf(p, " %10s", irq_desc[i].chip->name ? : "-");
81                 seq_printf(p, "  %s", action->name);
82                 for (action = action->next; action; action = action->next)
83                         seq_printf(p, ", %s", action->name);
84
85                 seq_putc(p, '\n');
86 unlock:
87                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
88         } else if (i == NR_IRQS) {
89 #ifdef CONFIG_ARCH_ACORN
90                 show_fiq_list(p, v);
91 #endif
92 #ifdef CONFIG_SMP
93                 show_ipi_list(p);
94                 show_local_irqs(p);
95 #endif
96                 seq_printf(p, "Err: %10lu\n", irq_err_count);
97         }
98         return 0;
99 }
100
101 /* Handle bad interrupts */
102 static struct irq_desc bad_irq_desc = {
103         .handle_irq = handle_bad_irq,
104         .lock = SPIN_LOCK_UNLOCKED
105 };
106
107 /*
108  * do_IRQ handles all hardware IRQ's.  Decoded IRQs should not
109  * come via this function.  Instead, they should provide their
110  * own 'handler'
111  */
112 asmlinkage void __exception asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
113 {
114         struct pt_regs *old_regs = set_irq_regs(regs);
115
116         irq_enter();
117
118         /*
119          * Some hardware gives randomly wrong interrupts.  Rather
120          * than crashing, do something sensible.
121          */
122         if (irq >= NR_IRQS)
123                 handle_bad_irq(irq, &bad_irq_desc);
124         else
125                 generic_handle_irq(irq);
126
127         /* AT91 specific workaround */
128         irq_finish(irq);
129
130         irq_exit();
131         set_irq_regs(old_regs);
132 }
133
134 void set_irq_flags(unsigned int irq, unsigned int iflags)
135 {
136         struct irq_desc *desc;
137         unsigned long flags;
138
139         if (irq >= NR_IRQS) {
140                 printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
141                 return;
142         }
143
144         desc = irq_desc + irq;
145         spin_lock_irqsave(&desc->lock, flags);
146         desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
147         if (iflags & IRQF_VALID)
148                 desc->status &= ~IRQ_NOREQUEST;
149         if (iflags & IRQF_PROBE)
150                 desc->status &= ~IRQ_NOPROBE;
151         if (!(iflags & IRQF_NOAUTOEN))
152                 desc->status &= ~IRQ_NOAUTOEN;
153         spin_unlock_irqrestore(&desc->lock, flags);
154 }
155
156 void __init init_IRQ(void)
157 {
158         int irq;
159
160         for (irq = 0; irq < NR_IRQS; irq++)
161                 irq_desc[irq].status |= IRQ_NOREQUEST | IRQ_NOPROBE;
162
163 #ifdef CONFIG_SMP
164         bad_irq_desc.affinity = CPU_MASK_ALL;
165         bad_irq_desc.cpu = smp_processor_id();
166 #endif
167         init_arch_irq();
168 }
169
170 #ifdef CONFIG_HOTPLUG_CPU
171
172 static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu)
173 {
174         pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->cpu, cpu);
175
176         spin_lock_irq(&desc->lock);
177         desc->chip->set_affinity(irq, cpumask_of_cpu(cpu));
178         spin_unlock_irq(&desc->lock);
179 }
180
181 /*
182  * The CPU has been marked offline.  Migrate IRQs off this CPU.  If
183  * the affinity settings do not allow other CPUs, force them onto any
184  * available CPU.
185  */
186 void migrate_irqs(void)
187 {
188         unsigned int i, cpu = smp_processor_id();
189
190         for (i = 0; i < NR_IRQS; i++) {
191                 struct irq_desc *desc = irq_desc + i;
192
193                 if (desc->cpu == cpu) {
194                         unsigned int newcpu = any_online_cpu(desc->affinity);
195
196                         if (newcpu == NR_CPUS) {
197                                 if (printk_ratelimit())
198                                         printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
199                                                i, cpu);
200
201                                 cpus_setall(desc->affinity);
202                                 newcpu = any_online_cpu(desc->affinity);
203                         }
204
205                         route_irq(desc, i, newcpu);
206                 }
207         }
208 }
209 #endif /* CONFIG_HOTPLUG_CPU */