/**
* @file nmi_int.c
*
* @remark Copyright 2002 OProfile authors
* @remark Read the file COPYING
*
* @author John Levon <levon@movementarian.org>
*/
#include <linux/init.h>
#include <linux/notifier.h>
#include <linux/smp.h>
#include <linux/oprofile.h>
#include <linux/sysdev.h>
#include <linux/slab.h>
#include <asm/nmi.h>
#include <asm/msr.h>
#include <asm/apic.h>
#include "op_counter.h"
#include "op_x86_model.h"
static struct op_x86_model_spec const * model;
static struct op_msrs cpu_msrs[NR_CPUS];
static unsigned long saved_lvtpc[NR_CPUS];
static int nmi_start(void);
static void nmi_stop(void);
/* 0 == registered but off, 1 == registered and on */
static int nmi_enabled = 0;
#ifdef CONFIG_PM
static int nmi_suspend(struct sys_device *dev, pm_message_t state)
{
if (nmi_enabled == 1)
nmi_stop();
return 0;
}
static int nmi_resume(struct sys_device *dev)
{
if (nmi_enabled == 1)
nmi_start();
return 0;
}
static struct sysdev_class oprofile_sysclass = {
set_kset_name("oprofile"),
.resume = nmi_resume,
.suspend = nmi_suspend,
};
static struct sys_device device_oprofile = {
.id = 0,
.cls = &oprofile_sysclass,
};
static int __init init_driverfs(void)
{
int error;
if (!(error = sysdev_class_register(&oprofile_sysclass)))
error = sysdev_register(&device_oprofile);
return error;
}
static void exit_driverfs(void)
{
sysdev_unregister(&device_oprofile);
sysdev_class_unregister(&oprofile_sysclass);
}
#else
#define init_driverfs() do { } while (0)
#define exit_driverfs() do { } while (0)
#endif /* CONFIG_PM */
static int nmi_callback(struct pt_regs * regs, int cpu)
{
return model->check_ctrs(regs, &cpu_msrs[cpu]);
}
static void nmi_cpu_save_registers(struct op_msrs * msrs)
{
unsigned int const nr_ctrs = model->num_counters;
unsigned int const nr_ctrls = model->num_controls;
struct op_msr * counters = msrs->counters;
struct op_msr * controls = msrs->controls;
unsigned int i;
for (i = 0; i < nr_ctrs; ++i) {
rdmsr(counters[i].addr,
counters[i].saved.low,
counters[i].saved.high);
}
for (i = 0; i < nr_ctrls; ++i) {
rdmsr(controls[i].addr,
controls[i].saved.low,
controls[i].saved.high);
}
}
static void nmi_save_registers(void * dummy)
{
int cpu = smp_processor_id();
struct op_msrs * msrs = &cpu_msrs[cpu];
model->fill_in_addresses(msrs);
nmi_cpu_save_registers(msrs);
}
static void free_msrs(void)
{
int i;
for_each_cpu(i) {
kfree(cpu_msrs[i].counters);
cpu_msrs[i].counters = NULL;
kfree(cpu_msrs[i].controls);
cpu_msrs[i].controls = NULL;
}
}
static int allocate_msrs(void)
{
int success = 1;
size_t controls_size = sizeof(struct op_msr) * model->num_controls;
size_t counters_size = sizeof(struct op_msr) * model->num_counters;
int i;
for_each_online_cpu(i) {
cpu_msrs[i].counters = kmalloc(counters_size, GFP_KERNEL);
if (!cpu_msrs[i].counters) {
success = 0;
break;
}
cpu_msrs[i].controls = kmalloc(controls_size, GFP_KERNEL);
if (!cpu_msrs[i].controls) {
success = 0;
break;
}
}
if (!success)
free_msrs();
return success;
}
static void nmi_cpu_setup(void * dummy)
{
int cpu = smp_processor_id();
struct op_msrs * msrs = &cpu_msrs[cpu];
spin_lock(&oprofilefs_lock);
model->setup_ctrs(msrs);
spin_unlock(&oprofilefs_lock);
saved_lvtpc[cpu] = apic_read(APIC_LVTPC);
apic_write(APIC_LVTPC, APIC_DM_NMI);
}
static int nmi_setup(void)
{
if (!allocate_msrs())
return -ENOMEM;
/* We walk a thin line between law and rape here.
* We need to be careful to install our NMI handler
* without actually triggering any NMIs as this will
* break the core code horrifically.
*/
if (reserve_lapic_nmi() < 0) {
free_msrs();
return -EBUSY;
}
/* We need to serialize save and setup for HT because the subset
* of msrs are distinct for save and setup operations
*/
on_each_cpu(nmi_save_registers, NULL, 0, 1);
on_each_cpu(nmi_cpu_setup, NULL, 0, 1);
set_nmi_callback(nmi_callback);
nmi_enabled = 1;
return 0;
}
static void nmi_restore_registers(struct op_msrs * msrs)
{
unsigned int const nr_ctrs = model->num_counters;
unsigned int const nr_ctrls = model->num_controls;
struct op_msr * counters = msrs->counters;
struct op_msr * controls = msrs->controls;
unsigned int i;
for (i = 0; i < nr_ctrls; ++i) {
wrmsr(controls[i].addr,
controls[i].saved.low,
controls[i].saved.high);
}
for (i = 0; i < nr_ctrs; ++i) {
wrmsr(counters[i].addr,
counters[i].saved.low,
counters[i].saved.high);
}
}
static void nmi_cpu_shutdown(void * dummy)
{
unsigned int v;
int cpu = smp_processor_id();
struct op_msrs * msrs = &cpu_msrs[cpu];
/* restoring APIC_LVTPC can trigger an apic error because the delivery
* mode and vector nr combination can be illegal. That's by design: on
* power on apic lvt contain a zero vector nr which are legal only for
* NMI delivery mode. So inhibit apic err before restoring lvtpc
*/
v = apic_read(APIC_LVTERR);
apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
apic_write(APIC_LVTPC, saved_lvtpc[cpu]);
apic_write(APIC_LVTERR, v);
nmi_restore_registers(msrs);
}
static void nmi_shutdown(void)
{
nmi_enabled = 0;
on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
unset_nmi_callback();
release_lapic_nmi();
free_msrs();
}
static void nmi_cpu_start(void * dummy)
{
struct op_msrs const * msrs = &cpu_msrs[smp_processor_id()];
model->start(msrs);
}
static int nmi_start(void)
{
on_each_cpu(nmi_cpu_start, NULL, 0, 1);
return 0;
}
static void nmi_cpu_stop(void * dummy)
{
struct op_msrs const * msrs = &cpu_msrs[smp_processor_id()];
model->stop(msrs);
}
static void nmi_stop(void)
{
on_each_cpu(nmi_cpu_stop, NULL, 0, 1);
}
struct op_counter_config counter_config[OP_MAX_COUNTER];
static int nmi_create_files(struct super_block * sb, struct dentry * root)
{
unsigned int i;
for (i = 0; i < model->num_counters; ++i) {
struct dentry * dir;
char buf[2];
snprintf(buf, 2, "%d", i);
dir = oprofilefs_mkdir(sb, root, buf);
oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);
oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);
oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
}
return 0;
}
static int __init p4_init(char ** cpu_type)
{
__u8 cpu_model = boot_cpu_data.x86_model;
if (cpu_model > 4)
return 0;
#ifndef CONFIG_SMP
*cpu_type = "i386/p4";
model = &op_p4_spec;
return 1;
#else
switch (smp_num_siblings) {
case 1:
*cpu_type = "i386/p4";
model = &op_p4_spec;
return 1;
case 2:
*cpu_type = "i386/p4-ht";
model = &op_p4_ht2_spec;
return 1;
}
#endif
printk(KERN_INFO "oprofile: P4 HyperThreading detected with > 2 threads\n");
printk(KERN_INFO "oprofile: Reverting to timer mode.\n");
return 0;
}
static int __init ppro_init(char ** cpu_type)
{
__u8 cpu_model = boot_cpu_data.x86_model;
if (cpu_model > 0xd)
return 0;
if (cpu_model == 9) {
*cpu_type = "i386/p6_mobile";
} else if (cpu_model > 5) {
*cpu_type = "i386/piii";
} else if (cpu_model > 2) {
*cpu_type = "i386/pii";
} else {
*cpu_type = "i386/ppro";
}
model = &op_ppro_spec;
return 1;
}
/* in order to get driverfs right */
static int using_nmi;
int __init op_nmi_init(struct oprofile_operations *ops)
{
__u8 vendor = boot_cpu_data.x86_vendor;
__u8 family = boot_cpu_data.x86;
char *cpu_type;
if (!cpu_has_apic)
return -ENODEV;
switch (vendor) {
case X86_VENDOR_AMD:
/* Needs to be at least an Athlon (or hammer in 32bit mode) */
switch (family) {
default:
return -ENODEV;
case 6:
model = &op_athlon_spec;
cpu_type = "i386/athlon";
break;
case 0xf:
model = &op_athlon_spec;
/* Actually it could be i386/hammer too, but give
user space an consistent name. */
cpu_type = "x86-64/hammer";
break;
}
break;
case X86_VENDOR_INTEL:
switch (family) {
/* Pentium IV */
case 0xf:
if (!p4_init(&cpu_type))
return -ENODEV;
break;
/* A P6-class processor */
case 6:
if (!ppro_init(&cpu_type))
return -ENODEV;
break;
default:
return -ENODEV;
}
break;
default:
return -ENODEV;
}
init_driverfs();
using_nmi = 1;
ops->create_files = nmi_create_files;
ops->setup = nmi_setup;
ops->shutdown = nmi_shutdown;
ops->start = nmi_start;
ops->stop = nmi_stop;
ops->cpu_type = cpu_type;
printk(KERN_INFO "oprofile: using NMI interrupt.\n");
return 0;
}
void op_nmi_exit(void)
{
if (using_nmi)
exit_driverfs();
}
