/* *  arch/s390/kernel/irq.c * *  S390 version *    Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), * * This file contains interrupt related functions. */#include <linux/module.h>#include <linux/kernel.h>#include <linux/kernel_stat.h>#include <linux/interrupt.h>#include <linux/seq_file.h>#include <linux/cpu.h>/* * show_interrupts is needed by /proc/interrupts. */int show_interrupts(struct seq_file *p, void *v){	static const char *intrclass_names[] = { "EXT", "I/O", };	int i = *(loff_t *) v, j;	if (i == 0) {		seq_puts(p, "           ");		for (j=0; j<NR_CPUS; j++)			if (cpu_online(j))				seq_printf(p, "CPU%d       ",j);		seq_putc(p, '\n');	}	if (i < NR_IRQS) {		seq_printf(p, "%s: ", intrclass_names[i]);#ifndef CONFIG_SMP		seq_printf(p, "%10u ", kstat_irqs(i));#else		for (j = 0; j < NR_CPUS; j++)			if (cpu_online(j))				seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);#endif                seq_putc(p, '\n');        }        return 0;}/* * For compatibilty only. S/390 specific setup of interrupts et al. is done * much later in init_channel_subsystem(). */void __initinit_IRQ(void){	/* nothing... */}/* * Switch to the asynchronous interrupt stack for softirq execution. */extern void __do_softirq(void);asmlinkage void do_softirq(void){	unsigned long flags, old, new;	if (in_interrupt())		return;	local_irq_save(flags);	account_system_vtime(current);	local_bh_disable();	if (local_softirq_pending()) {		/* Get current stack pointer. */		asm volatile("la %0,0(15)" : "=a" (old));		/* Check against async. stack address range. */		new = S390_lowcore.async_stack;		if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {			/* Need to switch to the async. stack. */			new -= STACK_FRAME_OVERHEAD;			((struct stack_frame *) new)->back_chain = old;			asm volatile("   la    15,0(%0)\n"				     "   basr  14,%2\n"				     "   la    15,0(%1)\n"				     : : "a" (new), "a" (old),				         "a" (__do_softirq)				     : "0", "1", "2", "3", "4", "5", "14",				       "cc", "memory" );		} else			/* We are already on the async stack. */			__do_softirq();	}	account_system_vtime(current);	__local_bh_enable();	local_irq_restore(flags);}EXPORT_SYMBOL(do_softirq);