163 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			163 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  *	linux/arch/alpha/kernel/irq.c
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|  *
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|  *	Copyright (C) 1995 Linus Torvalds
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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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| 
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| #include <linux/kernel.h>
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| #include <linux/module.h>
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| #include <linux/errno.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/ptrace.h>
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| #include <linux/interrupt.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/irq.h>
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| #include <linux/proc_fs.h>
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| #include <linux/seq_file.h>
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| #include <linux/profile.h>
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| #include <linux/bitops.h>
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| 
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| #include <asm/system.h>
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| #include <asm/io.h>
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| #include <asm/uaccess.h>
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| 
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| volatile unsigned long irq_err_count;
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| 
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| void ack_bad_irq(unsigned int irq)
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| {
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| 	irq_err_count++;
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| 	printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
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| }
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| 
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| #ifdef CONFIG_SMP 
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| static char irq_user_affinity[NR_IRQS];
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| 
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| int irq_select_affinity(unsigned int irq)
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| {
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| 	static int last_cpu;
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| 	int cpu = last_cpu + 1;
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| 
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| 	if (!irq_desc[irq].chip->set_affinity || irq_user_affinity[irq])
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| 		return 1;
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| 
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| 	while (!cpu_possible(cpu) ||
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| 	       !cpumask_test_cpu(cpu, irq_default_affinity))
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| 		cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
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| 	last_cpu = cpu;
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| 
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| 	cpumask_copy(irq_desc[irq].affinity, cpumask_of(cpu));
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| 	irq_desc[irq].chip->set_affinity(irq, cpumask_of(cpu));
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| 	return 0;
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| }
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| #endif /* CONFIG_SMP */
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| 
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| int
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| show_interrupts(struct seq_file *p, void *v)
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| {
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| #ifdef CONFIG_SMP
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| 	int j;
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| #endif
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| 	int irq = *(loff_t *) v;
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| 	struct irqaction * action;
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| 	unsigned long flags;
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| 
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| #ifdef CONFIG_SMP
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| 	if (irq == 0) {
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| 		seq_puts(p, "           ");
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| 		for_each_online_cpu(j)
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| 			seq_printf(p, "CPU%d       ", j);
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| 		seq_putc(p, '\n');
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| 	}
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| #endif
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| 
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| 	if (irq < ACTUAL_NR_IRQS) {
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| 		spin_lock_irqsave(&irq_desc[irq].lock, flags);
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| 		action = irq_desc[irq].action;
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| 		if (!action) 
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| 			goto unlock;
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| 		seq_printf(p, "%3d: ", irq);
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| #ifndef CONFIG_SMP
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| 		seq_printf(p, "%10u ", kstat_irqs(irq));
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| #else
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| 		for_each_online_cpu(j)
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| 			seq_printf(p, "%10u ", kstat_irqs_cpu(irq, j));
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| #endif
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| 		seq_printf(p, " %14s", irq_desc[irq].chip->name);
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| 		seq_printf(p, "  %c%s",
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| 			(action->flags & IRQF_DISABLED)?'+':' ',
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| 			action->name);
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| 
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| 		for (action=action->next; action; action = action->next) {
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| 			seq_printf(p, ", %c%s",
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| 				  (action->flags & IRQF_DISABLED)?'+':' ',
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| 				   action->name);
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| 		}
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| 
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| 		seq_putc(p, '\n');
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| unlock:
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| 		spin_unlock_irqrestore(&irq_desc[irq].lock, flags);
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| 	} else if (irq == ACTUAL_NR_IRQS) {
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| #ifdef CONFIG_SMP
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| 		seq_puts(p, "IPI: ");
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| 		for_each_online_cpu(j)
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| 			seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
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| 		seq_putc(p, '\n');
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| #endif
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| 		seq_printf(p, "ERR: %10lu\n", irq_err_count);
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| 	}
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| 	return 0;
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| }
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| 
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| /*
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|  * handle_irq handles all normal device IRQ's (the special
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|  * SMP cross-CPU interrupts have their own specific
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|  * handlers).
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|  */
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| 
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| #define MAX_ILLEGAL_IRQS 16
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| 
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| void
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| handle_irq(int irq)
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| {	
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| 	/* 
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| 	 * We ack quickly, we don't want the irq controller
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| 	 * thinking we're snobs just because some other CPU has
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| 	 * disabled global interrupts (we have already done the
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| 	 * INT_ACK cycles, it's too late to try to pretend to the
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| 	 * controller that we aren't taking the interrupt).
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| 	 *
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| 	 * 0 return value means that this irq is already being
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| 	 * handled by some other CPU. (or is disabled)
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| 	 */
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| 	static unsigned int illegal_count=0;
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| 	
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| 	if ((unsigned) irq > ACTUAL_NR_IRQS && illegal_count < MAX_ILLEGAL_IRQS ) {
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| 		irq_err_count++;
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| 		illegal_count++;
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| 		printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
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| 		       irq);
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| 		return;
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| 	}
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| 
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| 	irq_enter();
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| 	/*
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| 	 * __do_IRQ() must be called with IPL_MAX. Note that we do not
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| 	 * explicitly enable interrupts afterwards - some MILO PALcode
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| 	 * (namely LX164 one) seems to have severe problems with RTI
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| 	 * at IPL 0.
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| 	 */
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| 	local_irq_disable();
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| 	__do_IRQ(irq);
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| 	irq_exit();
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| }
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