1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
298 lines
6.6 KiB
C
298 lines
6.6 KiB
C
/*
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*
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* linux/arch/cris/kernel/irq.c
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*
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* Copyright (c) 2000,2001 Axis Communications AB
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*
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* Authors: Bjorn Wesen (bjornw@axis.com)
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*
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* This file contains the code used by various IRQ handling routines:
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* asking for different IRQ's should be done through these routines
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* instead of just grabbing them. Thus setups with different IRQ numbers
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* shouldn't result in any weird surprises, and installing new handlers
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* should be easier.
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*
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* Notice Linux/CRIS: these routines do not care about SMP
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*
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*/
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/*
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* IRQ's are in fact implemented a bit like signal handlers for the kernel.
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* Naturally it's not a 1:1 relation, but there are similarities.
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/ptrace.h>
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#include <linux/kernel_stat.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/ioport.h>
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#include <linux/interrupt.h>
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#include <linux/timex.h>
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#include <linux/slab.h>
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#include <linux/random.h>
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#include <linux/init.h>
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#include <linux/seq_file.h>
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#include <linux/errno.h>
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#include <linux/bitops.h>
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#include <asm/io.h>
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/* Defined in arch specific irq.c */
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extern void arch_setup_irq(int irq);
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extern void arch_free_irq(int irq);
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void
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disable_irq(unsigned int irq_nr)
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{
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unsigned long flags;
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local_save_flags(flags);
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local_irq_disable();
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mask_irq(irq_nr);
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local_irq_restore(flags);
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}
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void
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enable_irq(unsigned int irq_nr)
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{
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unsigned long flags;
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local_save_flags(flags);
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local_irq_disable();
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unmask_irq(irq_nr);
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local_irq_restore(flags);
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}
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unsigned long
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probe_irq_on()
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{
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return 0;
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}
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EXPORT_SYMBOL(probe_irq_on);
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int
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probe_irq_off(unsigned long x)
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{
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return 0;
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}
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EXPORT_SYMBOL(probe_irq_off);
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/*
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* Initial irq handlers.
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*/
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static struct irqaction *irq_action[NR_IRQS];
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int show_interrupts(struct seq_file *p, void *v)
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{
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int i = *(loff_t *) v;
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struct irqaction * action;
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unsigned long flags;
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if (i < NR_IRQS) {
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local_irq_save(flags);
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action = irq_action[i];
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if (!action)
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goto skip;
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seq_printf(p, "%2d: %10u %c %s",
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i, kstat_this_cpu.irqs[i],
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(action->flags & SA_INTERRUPT) ? '+' : ' ',
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action->name);
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for (action = action->next; action; action = action->next) {
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seq_printf(p, ",%s %s",
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(action->flags & SA_INTERRUPT) ? " +" : "",
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action->name);
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}
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seq_putc(p, '\n');
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skip:
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local_irq_restore(flags);
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}
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return 0;
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}
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/* called by the assembler IRQ entry functions defined in irq.h
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* to dispatch the interrupts to registred handlers
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* interrupts are disabled upon entry - depending on if the
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* interrupt was registred with SA_INTERRUPT or not, interrupts
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* are re-enabled or not.
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*/
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asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
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{
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struct irqaction *action;
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int do_random, cpu;
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int ret, retval = 0;
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cpu = smp_processor_id();
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irq_enter();
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kstat_cpu(cpu).irqs[irq - FIRST_IRQ]++;
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action = irq_action[irq - FIRST_IRQ];
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if (action) {
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if (!(action->flags & SA_INTERRUPT))
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local_irq_enable();
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do_random = 0;
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do {
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ret = action->handler(irq, action->dev_id, regs);
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if (ret == IRQ_HANDLED)
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do_random |= action->flags;
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retval |= ret;
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action = action->next;
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} while (action);
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if (retval != 1) {
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if (retval) {
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printk("irq event %d: bogus retval mask %x\n",
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irq, retval);
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} else {
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printk("irq %d: nobody cared\n", irq);
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}
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}
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if (do_random & SA_SAMPLE_RANDOM)
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add_interrupt_randomness(irq);
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local_irq_disable();
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}
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irq_exit();
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}
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/* this function links in a handler into the chain of handlers for the
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given irq, and if the irq has never been registred, the appropriate
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handler is entered into the interrupt vector
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*/
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int setup_irq(int irq, struct irqaction * new)
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{
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int shared = 0;
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struct irqaction *old, **p;
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unsigned long flags;
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p = irq_action + irq - FIRST_IRQ;
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if ((old = *p) != NULL) {
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/* Can't share interrupts unless both agree to */
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if (!(old->flags & new->flags & SA_SHIRQ))
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return -EBUSY;
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/* Can't share interrupts unless both are same type */
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if ((old->flags ^ new->flags) & SA_INTERRUPT)
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return -EBUSY;
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/* add new interrupt at end of irq queue */
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do {
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p = &old->next;
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old = *p;
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} while (old);
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shared = 1;
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}
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if (new->flags & SA_SAMPLE_RANDOM)
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rand_initialize_irq(irq);
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local_save_flags(flags);
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local_irq_disable();
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*p = new;
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if (!shared) {
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/* if the irq wasn't registred before, enter it into the vector table
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and unmask it physically
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*/
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arch_setup_irq(irq);
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unmask_irq(irq);
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}
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local_irq_restore(flags);
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return 0;
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}
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/* this function is called by a driver to register an irq handler
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Valid flags:
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SA_INTERRUPT -> it's a fast interrupt, handler called with irq disabled and
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no signal checking etc is performed upon exit
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SA_SHIRQ -> the interrupt can be shared between different handlers, the handler
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is required to check if the irq was "aimed" at it explicitely
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SA_RANDOM -> the interrupt will add to the random generators entropy
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*/
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int request_irq(unsigned int irq,
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irqreturn_t (*handler)(int, void *, struct pt_regs *),
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unsigned long irqflags,
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const char * devname,
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void *dev_id)
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{
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int retval;
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struct irqaction * action;
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if(!handler)
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return -EINVAL;
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/* allocate and fill in a handler structure and setup the irq */
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action = (struct irqaction *)kmalloc(sizeof(struct irqaction), GFP_KERNEL);
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if (!action)
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return -ENOMEM;
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action->handler = handler;
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action->flags = irqflags;
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cpus_clear(action->mask);
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action->name = devname;
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action->next = NULL;
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action->dev_id = dev_id;
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retval = setup_irq(irq, action);
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if (retval)
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kfree(action);
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return retval;
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}
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EXPORT_SYMBOL(request_irq);
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void free_irq(unsigned int irq, void *dev_id)
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{
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struct irqaction * action, **p;
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unsigned long flags;
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if (irq >= NR_IRQS) {
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printk("Trying to free IRQ%d\n",irq);
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return;
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}
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for (p = irq - FIRST_IRQ + irq_action; (action = *p) != NULL; p = &action->next) {
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if (action->dev_id != dev_id)
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continue;
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/* Found it - now free it */
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local_save_flags(flags);
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local_irq_disable();
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*p = action->next;
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if (!irq_action[irq - FIRST_IRQ]) {
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mask_irq(irq);
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arch_free_irq(irq);
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}
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local_irq_restore(flags);
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kfree(action);
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return;
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}
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printk("Trying to free free IRQ%d\n",irq);
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}
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EXPORT_SYMBOL(free_irq);
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void weird_irq(void)
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{
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local_irq_disable();
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printk("weird irq\n");
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while(1);
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}
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#if defined(CONFIG_PROC_FS) && defined(CONFIG_SYSCTL)
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/* Used by other archs to show/control IRQ steering during SMP */
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void __init
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init_irq_proc(void)
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{
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}
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#endif
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