linux/arch/s390/kernel/irq.c

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/*
* arch/s390/kernel/irq.c
*
* Copyright IBM Corp. 2004,2007
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Thomas Spatzier (tspat@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>
#include <linux/proc_fs.h>
#include <linux/profile.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;
get_online_cpus();
if (i == 0) {
seq_puts(p, " ");
for_each_online_cpu(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_each_online_cpu(j)
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#endif
seq_putc(p, '\n');
}
put_online_cpus();
return 0;
}
/*
* For compatibilty only. S/390 specific setup of interrupts et al. is done
* much later in init_channel_subsystem().
*/
void __init
init_IRQ(void)
{
/* nothing... */
}
/*
* Switch to the asynchronous interrupt stack for softirq execution.
*/
asmlinkage void do_softirq(void)
{
unsigned long flags, old, new;
if (in_interrupt())
return;
local_irq_save(flags);
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();
}
local_irq_restore(flags);
}
void init_irq_proc(void)
{
struct proc_dir_entry *root_irq_dir;
root_irq_dir = proc_mkdir("irq", NULL);
create_prof_cpu_mask(root_irq_dir);
}