3 * linux/arch/cris/kernel/irq.c
5 * Copyright (c) 2000,2001 Axis Communications AB
7 * Authors: Bjorn Wesen (bjornw@axis.com)
9 * This file contains the code used by various IRQ handling routines:
10 * asking for different IRQ's should be done through these routines
11 * instead of just grabbing them. Thus setups with different IRQ numbers
12 * shouldn't result in any weird surprises, and installing new handlers
15 * Notice Linux/CRIS: these routines do not care about SMP
20 * IRQ's are in fact implemented a bit like signal handlers for the kernel.
21 * Naturally it's not a 1:1 relation, but there are similarities.
24 #include <linux/config.h>
25 #include <linux/module.h>
26 #include <linux/ptrace.h>
28 #include <linux/kernel_stat.h>
29 #include <linux/signal.h>
30 #include <linux/sched.h>
31 #include <linux/ioport.h>
32 #include <linux/interrupt.h>
33 #include <linux/timex.h>
34 #include <linux/slab.h>
35 #include <linux/random.h>
36 #include <linux/init.h>
37 #include <linux/seq_file.h>
38 #include <linux/errno.h>
41 #include <asm/bitops.h>
43 /* Defined in arch specific irq.c */
44 extern void arch_setup_irq(int irq);
45 extern void arch_free_irq(int irq);
48 disable_irq(unsigned int irq_nr)
52 local_save_flags(flags);
55 local_irq_restore(flags);
59 enable_irq(unsigned int irq_nr)
62 local_save_flags(flags);
65 local_irq_restore(flags);
74 EXPORT_SYMBOL(probe_irq_on);
77 probe_irq_off(unsigned long x)
82 EXPORT_SYMBOL(probe_irq_off);
85 * Initial irq handlers.
88 static struct irqaction *irq_action[NR_IRQS];
90 int show_interrupts(struct seq_file *p, void *v)
92 int i = *(loff_t *) v;
93 struct irqaction * action;
97 local_irq_save(flags);
98 action = irq_action[i];
101 seq_printf(p, "%2d: %10u %c %s",
102 i, kstat_this_cpu.irqs[i],
103 (action->flags & SA_INTERRUPT) ? '+' : ' ',
105 for (action = action->next; action; action = action->next) {
106 seq_printf(p, ",%s %s",
107 (action->flags & SA_INTERRUPT) ? " +" : "",
112 local_irq_restore(flags);
117 /* called by the assembler IRQ entry functions defined in irq.h
118 * to dispatch the interrupts to registred handlers
119 * interrupts are disabled upon entry - depending on if the
120 * interrupt was registred with SA_INTERRUPT or not, interrupts
121 * are re-enabled or not.
124 asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
126 struct irqaction *action;
130 cpu = smp_processor_id();
132 kstat_cpu(cpu).irqs[irq - FIRST_IRQ]++;
133 action = irq_action[irq - FIRST_IRQ];
136 if (!(action->flags & SA_INTERRUPT))
140 do_random |= action->flags;
141 retval |= action->handler(irq, action->dev_id, regs);
142 action = action->next;
147 printk("irq event %d: bogus retval mask %x\n",
150 printk("irq %d: nobody cared\n", irq);
154 if (do_random & SA_SAMPLE_RANDOM)
155 add_interrupt_randomness(irq);
160 if (softirq_pending(cpu))
163 /* unmasking and bottom half handling is done magically for us. */
166 /* this function links in a handler into the chain of handlers for the
167 given irq, and if the irq has never been registred, the appropriate
168 handler is entered into the interrupt vector
171 int setup_irq(int irq, struct irqaction * new)
174 struct irqaction *old, **p;
177 p = irq_action + irq - FIRST_IRQ;
178 if ((old = *p) != NULL) {
179 /* Can't share interrupts unless both agree to */
180 if (!(old->flags & new->flags & SA_SHIRQ))
183 /* Can't share interrupts unless both are same type */
184 if ((old->flags ^ new->flags) & SA_INTERRUPT)
187 /* add new interrupt at end of irq queue */
195 if (new->flags & SA_SAMPLE_RANDOM)
196 rand_initialize_irq(irq);
198 local_save_flags(flags);
203 /* if the irq wasn't registred before, enter it into the vector table
204 and unmask it physically
210 local_irq_restore(flags);
214 /* this function is called by a driver to register an irq handler
216 SA_INTERRUPT -> it's a fast interrupt, handler called with irq disabled and
217 no signal checking etc is performed upon exit
218 SA_SHIRQ -> the interrupt can be shared between different handlers, the handler
219 is required to check if the irq was "aimed" at it explicitely
220 SA_RANDOM -> the interrupt will add to the random generators entropy
223 int request_irq(unsigned int irq,
224 irqreturn_t (*handler)(int, void *, struct pt_regs *),
225 unsigned long irqflags,
226 const char * devname,
230 struct irqaction * action;
235 /* allocate and fill in a handler structure and setup the irq */
237 action = (struct irqaction *)kmalloc(sizeof(struct irqaction), GFP_KERNEL);
241 action->handler = handler;
242 action->flags = irqflags;
243 cpus_clear(action->mask);
244 action->name = devname;
246 action->dev_id = dev_id;
248 retval = setup_irq(irq, action);
255 EXPORT_SYMBOL(request_irq);
257 void free_irq(unsigned int irq, void *dev_id)
259 struct irqaction * action, **p;
262 if (irq >= NR_IRQS) {
263 printk("Trying to free IRQ%d\n",irq);
266 for (p = irq - FIRST_IRQ + irq_action; (action = *p) != NULL; p = &action->next) {
267 if (action->dev_id != dev_id)
270 /* Found it - now free it */
271 local_save_flags(flags);
274 if (!irq_action[irq - FIRST_IRQ]) {
278 local_irq_restore(flags);
282 printk("Trying to free free IRQ%d\n",irq);
285 EXPORT_SYMBOL(free_irq);
290 printk("weird irq\n");
294 #if defined(CONFIG_PROC_FS) && defined(CONFIG_SYSCTL)
295 /* Used by other archs to show/control IRQ steering during SMP */