kernel-ark/arch/alpha/kernel/irq.c
Michael Cree 65d920646a alpha: add performance monitor interrupt counter
The following patches implement hardware performance events for the Alpha
EV67 and later CPUs.  I have had this running on a Compaq XP1000 (EV67,
single CPU) for a few days now.  Pretty cool -- discovered that the glibc
exp2() library routine uses on average 985 cycles to execute 777 CPU
instructions whereas Compaq's CPML library version of exp2() uses on
average 32 cycles to execute 47 CPU instructions to achieve the same
thing!

This patch:

Add performance monitor interrupt counternd and export the count to user
space via /proc/interrupts.

Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jay Estabrook <jay.estabrook@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:45:03 -07:00

165 lines
4.0 KiB
C

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