blob: 80a06158da8226db05c9b2c8bf71a1ca71f8ff58 [file] [log] [blame]
/*
* AVR32 Performance Counter Driver
*
* Copyright (C) 2005-2007 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Author: Ronny Pedersen
*/
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/oprofile.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <asm/sysreg.h>
#define AVR32_PERFCTR_IRQ_GROUP 0
#define AVR32_PERFCTR_IRQ_LINE 1
void avr32_backtrace(struct pt_regs * const regs, unsigned int depth);
enum { PCCNT, PCNT0, PCNT1, NR_counter };
struct avr32_perf_counter {
unsigned long enabled;
unsigned long event;
unsigned long count;
unsigned long unit_mask;
unsigned long kernel;
unsigned long user;
u32 ie_mask;
u32 flag_mask;
};
static struct avr32_perf_counter counter[NR_counter] = {
{
.ie_mask = SYSREG_BIT(IEC),
.flag_mask = SYSREG_BIT(FC),
}, {
.ie_mask = SYSREG_BIT(IE0),
.flag_mask = SYSREG_BIT(F0),
}, {
.ie_mask = SYSREG_BIT(IE1),
.flag_mask = SYSREG_BIT(F1),
},
};
static void avr32_perf_counter_reset(void)
{
/* Reset all counter and disable/clear all interrupts */
sysreg_write(PCCR, (SYSREG_BIT(PCCR_R)
| SYSREG_BIT(PCCR_C)
| SYSREG_BIT(FC)
| SYSREG_BIT(F0)
| SYSREG_BIT(F1)));
}
static irqreturn_t avr32_perf_counter_interrupt(int irq, void *dev_id)
{
struct avr32_perf_counter *ctr = dev_id;
struct pt_regs *regs;
u32 pccr;
if (likely(!(intc_get_pending(AVR32_PERFCTR_IRQ_GROUP)
& (1 << AVR32_PERFCTR_IRQ_LINE))))
return IRQ_NONE;
regs = get_irq_regs();
pccr = sysreg_read(PCCR);
/* Clear the interrupt flags we're about to handle */
sysreg_write(PCCR, pccr);
/* PCCNT */
if (ctr->enabled && (pccr & ctr->flag_mask)) {
sysreg_write(PCCNT, -ctr->count);
oprofile_add_sample(regs, PCCNT);
}
ctr++;
/* PCNT0 */
if (ctr->enabled && (pccr & ctr->flag_mask)) {
sysreg_write(PCNT0, -ctr->count);
oprofile_add_sample(regs, PCNT0);
}
ctr++;
/* PCNT1 */
if (ctr->enabled && (pccr & ctr->flag_mask)) {
sysreg_write(PCNT1, -ctr->count);
oprofile_add_sample(regs, PCNT1);
}
return IRQ_HANDLED;
}
static int avr32_perf_counter_create_files(struct dentry *root)
{
struct dentry *dir;
unsigned int i;
char filename[4];
for (i = 0; i < NR_counter; i++) {
snprintf(filename, sizeof(filename), "%u", i);
dir = oprofilefs_mkdir(root->d_sb, root, filename);
oprofilefs_create_ulong(root->d_sb, dir, "enabled",
&counter[i].enabled);
oprofilefs_create_ulong(root->d_sb, dir, "event",
&counter[i].event);
oprofilefs_create_ulong(root->d_sb, dir, "count",
&counter[i].count);
/* Dummy entries */
oprofilefs_create_ulong(root->d_sb, dir, "kernel",
&counter[i].kernel);
oprofilefs_create_ulong(root->d_sb, dir, "user",
&counter[i].user);
oprofilefs_create_ulong(root->d_sb, dir, "unit_mask",
&counter[i].unit_mask);
}
return 0;
}
static int avr32_perf_counter_setup(void)
{
struct avr32_perf_counter *ctr;
u32 pccr;
int ret;
int i;
pr_debug("avr32_perf_counter_setup\n");
if (sysreg_read(PCCR) & SYSREG_BIT(PCCR_E)) {
printk(KERN_ERR
"oprofile: setup: perf counter already enabled\n");
return -EBUSY;
}
ret = request_irq(AVR32_PERFCTR_IRQ_GROUP,
avr32_perf_counter_interrupt, IRQF_SHARED,
"oprofile", counter);
if (ret)
return ret;
avr32_perf_counter_reset();
pccr = 0;
for (i = PCCNT; i < NR_counter; i++) {
ctr = &counter[i];
if (!ctr->enabled)
continue;
pr_debug("enabling counter %d...\n", i);
pccr |= ctr->ie_mask;
switch (i) {
case PCCNT:
/* PCCNT always counts cycles, so no events */
sysreg_write(PCCNT, -ctr->count);
break;
case PCNT0:
pccr |= SYSREG_BF(CONF0, ctr->event);
sysreg_write(PCNT0, -ctr->count);
break;
case PCNT1:
pccr |= SYSREG_BF(CONF1, ctr->event);
sysreg_write(PCNT1, -ctr->count);
break;
}
}
pr_debug("oprofile: writing 0x%x to PCCR...\n", pccr);
sysreg_write(PCCR, pccr);
return 0;
}
static void avr32_perf_counter_shutdown(void)
{
pr_debug("avr32_perf_counter_shutdown\n");
avr32_perf_counter_reset();
free_irq(AVR32_PERFCTR_IRQ_GROUP, counter);
}
static int avr32_perf_counter_start(void)
{
pr_debug("avr32_perf_counter_start\n");
sysreg_write(PCCR, sysreg_read(PCCR) | SYSREG_BIT(PCCR_E));
return 0;
}
static void avr32_perf_counter_stop(void)
{
pr_debug("avr32_perf_counter_stop\n");
sysreg_write(PCCR, sysreg_read(PCCR) & ~SYSREG_BIT(PCCR_E));
}
static struct oprofile_operations avr32_perf_counter_ops __initdata = {
.create_files = avr32_perf_counter_create_files,
.setup = avr32_perf_counter_setup,
.shutdown = avr32_perf_counter_shutdown,
.start = avr32_perf_counter_start,
.stop = avr32_perf_counter_stop,
.cpu_type = "avr32",
};
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
if (!(current_cpu_data.features & AVR32_FEATURE_PCTR))
return -ENODEV;
memcpy(ops, &avr32_perf_counter_ops,
sizeof(struct oprofile_operations));
ops->backtrace = avr32_backtrace;
printk(KERN_INFO "oprofile: using AVR32 performance monitoring.\n");
return 0;
}
void oprofile_arch_exit(void)
{
}