- 根目录:
- arch
- x86
- kernel
- cpu
- perf_event_amd_uncore.c
/*
* Copyright (C) 2013 Advanced Micro Devices, Inc.
*
* Author: Jacob Shin <jacob.shin@amd.com>
*
* 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.
*/
#include <linux/perf_event.h>
#include <linux/percpu.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <asm/cpufeature.h>
#include <asm/perf_event.h>
#include <asm/msr.h>
#define NUM_COUNTERS_NB 4
#define NUM_COUNTERS_L2 4
#define MAX_COUNTERS NUM_COUNTERS_NB
#define RDPMC_BASE_NB 6
#define RDPMC_BASE_L2 10
#define COUNTER_SHIFT 16
struct amd_uncore {
int id;
int refcnt;
int cpu;
int num_counters;
int rdpmc_base;
u32 msr_base;
cpumask_t *active_mask;
struct pmu *pmu;
struct perf_event *events[MAX_COUNTERS];
struct amd_uncore *free_when_cpu_online;
};
static struct amd_uncore * __percpu *amd_uncore_nb;
static struct amd_uncore * __percpu *amd_uncore_l2;
static struct pmu amd_nb_pmu;
static struct pmu amd_l2_pmu;
static cpumask_t amd_nb_active_mask;
static cpumask_t amd_l2_active_mask;
static bool is_nb_event(struct perf_event *event)
{
return event->pmu->type == amd_nb_pmu.type;
}
static bool is_l2_event(struct perf_event *event)
{
return event->pmu->type == amd_l2_pmu.type;
}
static struct amd_uncore *event_to_amd_uncore(struct perf_event *event)
{
if (is_nb_event(event) && amd_uncore_nb)
return *per_cpu_ptr(amd_uncore_nb, event->cpu);
else if (is_l2_event(event) && amd_uncore_l2)
return *per_cpu_ptr(amd_uncore_l2, event->cpu);
return NULL;
}
static void amd_uncore_read(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
u64 prev, new;
s64 delta;
/*
* since we do not enable counter overflow interrupts,
* we do not have to worry about prev_count changing on us
*/
prev = local64_read(&hwc->prev_count);
rdpmcl(hwc->event_base_rdpmc, new);
local64_set(&hwc->prev_count, new);
delta = (new << COUNTER_SHIFT) - (prev << COUNTER_SHIFT);
delta >>= COUNTER_SHIFT;
local64_add(delta, &event->count);
}
static void amd_uncore_start(struct perf_event *event, int flags)
{
struct hw_perf_event *hwc = &event->hw;
if (flags & PERF_EF_RELOAD)
wrmsrl(hwc->event_base, (u64)local64_read(&hwc->prev_count));
hwc->state = 0;
wrmsrl(hwc->config_base, (hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE));
perf_event_update_userpage(event);
}
static void amd_uncore_stop(struct perf_event *event, int flags)
{
struct hw_perf_event *hwc = &event->hw;
wrmsrl(hwc->config_base, hwc->config);
hwc->state |= PERF_HES_STOPPED;
if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
amd_uncore_read(event);
hwc->state |= PERF_HES_UPTODATE;
}
}
static int amd_uncore_add(struct perf_event *event, int flags)
{
int i;
struct amd_uncore *uncore = event_to_amd_uncore(event);
struct hw_perf_event *hwc = &event->hw;
/* are we already assigned? */
if (hwc->idx != -1 && uncore->events[hwc->idx] == event)
goto out;
for (i = 0; i < uncore->num_counters; i++) {
if (uncore->events[i] == event) {
hwc->idx = i;
goto out;
}
}
/* if not, take the first available counter */
hwc->idx = -1;
for (i = 0; i < uncore->num_counters; i++) {
if (cmpxchg(&uncore->events[i], NULL, event) == NULL) {
hwc->idx = i;
break;
}
}
out:
if (hwc->idx == -1)
return -EBUSY;
hwc->config_base = uncore->msr_base + (2 * hwc->idx);
hwc->event_base = uncore->msr_base + 1 + (2 * hwc->idx);
hwc->event_base_rdpmc = uncore->rdpmc_base + hwc->idx;
hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
if (flags & PERF_EF_START)
amd_uncore_start(event, PERF_EF_RELOAD);
return 0;
}
static void amd_uncore_del(struct perf_event *event, int flags)
{
int i;
struct amd_uncore *uncore = event_to_amd_uncore(event);
struct hw_perf_event *hwc = &event->hw;
amd_uncore_stop(event, PERF_EF_UPDATE);
for (i = 0; i < uncore->num_counters; i++) {
if (cmpxchg(&uncore->events[i], event, NULL) == event)
break;
}
hwc->idx = -1;
}
static int amd_uncore_event_init(struct perf_event *event)
{
struct amd_uncore *uncore;
struct hw_perf_event *hwc = &event->hw;
if (event->attr.type != event->pmu->type)
return -ENOENT;
/*
* NB and L2 counters (MSRs) are shared across all cores that share the
* same NB / L2 cache. Interrupts can be directed to a single target
* core, however, event counts generated by processes running on other
* cores cannot be masked out. So we do not support sampling and
* per-thread events.
*/
if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
return -EINVAL;
/* NB and L2 counters do not have usr/os/guest/host bits */
if (event->attr.exclude_user || event->attr.exclude_kernel ||
event->attr.exclude_host || event->attr.exclude_guest)
return -EINVAL;
/* and we do not enable counter overflow interrupts */
hwc->config = event->attr.config & AMD64_RAW_EVENT_MASK_NB;
hwc->idx = -1;
if (event->cpu < 0)
return -EINVAL;
uncore = event_to_amd_uncore(event);
if (!uncore)
return -ENODEV;
/*
* since request can come in to any of the shared cores, we will remap
* to a single common cpu.
*/
event->cpu = uncore->cpu;
return 0;
}
static ssize_t amd_uncore_attr_show_cpumask(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int n;
cpumask_t *active_mask;
struct pmu *pmu = dev_get_drvdata(dev);
if (pmu->type == amd_nb_pmu.type)
active_mask = &amd_nb_active_mask;
else if (pmu->type == amd_l2_pmu.type)
active_mask = &amd_l2_active_mask;
else
return 0;
n = cpulist_scnprintf(buf, PAGE_SIZE - 2, active_mask);
buf[n++] = '\n';
buf[n] = '\0';
return n;
}
static DEVICE_ATTR(cpumask, S_IRUGO, amd_uncore_attr_show_cpumask, NULL);
static struct attribute *amd_uncore_attrs[] = {
&dev_attr_cpumask.attr,
NULL,
};
static struct attribute_group amd_uncore_attr_group = {
.attrs = amd_uncore_attrs,
};
PMU_FORMAT_ATTR(event, "config:0-7,32-35");
PMU_FORMAT_ATTR(umask, "config:8-15");
static struct attribute *amd_uncore_format_attr[] = {
&format_attr_event.attr,
&format_attr_umask.attr,
NULL,
};
static struct attribute_group amd_uncore_format_group = {
.name = "format",
.attrs = amd_uncore_format_attr,
};
static const struct attribute_group *amd_uncore_attr_groups[] = {
&amd_uncore_attr_group,
&amd_uncore_format_group,
NULL,
};
static struct pmu amd_nb_pmu = {
.attr_groups = amd_uncore_attr_groups,
.name = "amd_nb",
.event_init = amd_uncore_event_init,
.add = amd_uncore_add,
.del = amd_uncore_del,
.start = amd_uncore_start,
.stop = amd_uncore_stop,
.read = amd_uncore_read,
};
static struct pmu amd_l2_pmu = {
.attr_groups = amd_uncore_attr_groups,
.name = "amd_l2",
.event_init = amd_uncore_event_init,
.add = amd_uncore_add,
.del = amd_uncore_del,
.start = amd_uncore_start,
.stop = amd_uncore_stop,
.read = amd_uncore_read,
};
static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
{
return kzalloc_node(sizeof(struct amd_uncore), GFP_KERNEL,
cpu_to_node(cpu));
}
static int amd_uncore_cpu_up_prepare(unsigned int cpu)
{
struct amd_uncore *uncore_nb = NULL, *uncore_l2;
if (amd_uncore_nb) {
uncore_nb = amd_uncore_alloc(cpu);
if (!uncore_nb)
goto fail;
uncore_nb->cpu = cpu;
uncore_nb->num_counters = NUM_COUNTERS_NB;
uncore_nb->rdpmc_base = RDPMC_BASE_NB;
uncore_nb->msr_base = MSR_F15H_NB_PERF_CTL;
uncore_nb->active_mask = &amd_nb_active_mask;
uncore_nb->pmu = &amd_nb_pmu;
*per_cpu_ptr(amd_uncore_nb, cpu) = uncore_nb;
}
if (amd_uncore_l2) {
uncore_l2 = amd_uncore_alloc(cpu);
if (!uncore_l2)
goto fail;
uncore_l2->cpu = cpu;
uncore_l2->num_counters = NUM_COUNTERS_L2;
uncore_l2->rdpmc_base = RDPMC_BASE_L2;
uncore_l2->msr_base = MSR_F16H_L2I_PERF_CTL;
uncore_l2->active_mask = &amd_l2_active_mask;
uncore_l2->pmu = &amd_l2_pmu;
*per_cpu_ptr(amd_uncore_l2, cpu) = uncore_l2;
}
return 0;
fail:
kfree(uncore_nb);
return -ENOMEM;
}
static struct amd_uncore *
amd_uncore_find_online_sibling(struct amd_uncore *this,
struct amd_uncore * __percpu *uncores)
{
unsigned int cpu;
struct amd_uncore *that;
for_each_online_cpu(cpu) {
that = *per_cpu_ptr(uncores, cpu);
if (!that)
continue;
if (this == that)
continue;
if (this->id == that->id) {
that->free_when_cpu_online = this;
this = that;
break;
}
}
this->refcnt++;
return this;
}
static void amd_uncore_cpu_starting(unsigned int cpu)
{
unsigned int eax, ebx, ecx, edx;
struct amd_uncore *uncore;
if (amd_uncore_nb) {
uncore = *per_cpu_ptr(amd_uncore_nb, cpu);
cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
uncore->id = ecx & 0xff;
uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_nb);
*per_cpu_ptr(amd_uncore_nb, cpu) = uncore;
}
if (amd_uncore_l2) {
unsigned int apicid = cpu_data(cpu).apicid;
unsigned int nshared;
uncore = *per_cpu_ptr(amd_uncore_l2, cpu);
cpuid_count(0x8000001d, 2, &eax, &ebx, &ecx, &edx);
nshared = ((eax >> 14) & 0xfff) + 1;
uncore->id = apicid - (apicid % nshared);
uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_l2);
*per_cpu_ptr(amd_uncore_l2, cpu) = uncore;
}
}
static void uncore_online(unsigned int cpu,
struct amd_uncore * __percpu *uncores)
{
struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
kfree(uncore->free_when_cpu_online);
uncore->free_when_cpu_online = NULL;
if (cpu == uncore->cpu)
cpumask_set_cpu(cpu, uncore->active_mask);
}
static void amd_uncore_cpu_online(unsigned int cpu)
{
if (amd_uncore_nb)
uncore_online(cpu, amd_uncore_nb);
if (amd_uncore_l2)
uncore_online(cpu, amd_uncore_l2);
}
static void uncore_down_prepare(unsigned int cpu,
struct amd_uncore * __percpu *uncores)
{
unsigned int i;
struct amd_uncore *this = *per_cpu_ptr(uncores, cpu);
if (this->cpu != cpu)
return;
/* this cpu is going down, migrate to a shared sibling if possible */
for_each_online_cpu(i) {
struct amd_uncore *that = *per_cpu_ptr(uncores, i);
if (cpu == i)
continue;
if (this == that) {
perf_pmu_migrate_context(this->pmu, cpu, i);
cpumask_clear_cpu(cpu, that->active_mask);
cpumask_set_cpu(i, that->active_mask);
that->cpu = i;
break;
}
}
}
static void amd_uncore_cpu_down_prepare(unsigned int cpu)
{
if (amd_uncore_nb)
uncore_down_prepare(cpu, amd_uncore_nb);
if (amd_uncore_l2)
uncore_down_prepare(cpu, amd_uncore_l2);
}
static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores)
{
struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
if (cpu == uncore->cpu)
cpumask_clear_cpu(cpu, uncore->active_mask);
if (!--uncore->refcnt)
kfree(uncore);
*per_cpu_ptr(uncores, cpu) = NULL;
}
static void amd_uncore_cpu_dead(unsigned int cpu)
{
if (amd_uncore_nb)
uncore_dead(cpu, amd_uncore_nb);
if (amd_uncore_l2)
uncore_dead(cpu, amd_uncore_l2);
}
static int
amd_uncore_cpu_notifier(struct notifier_block *self, unsigned long action,
void *hcpu)
{
unsigned int cpu = (long)hcpu;
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_UP_PREPARE:
if (amd_uncore_cpu_up_prepare(cpu))
return notifier_from_errno(-ENOMEM);
break;
case CPU_STARTING:
amd_uncore_cpu_starting(cpu);
break;
case CPU_ONLINE:
amd_uncore_cpu_online(cpu);
break;
case CPU_DOWN_PREPARE:
amd_uncore_cpu_down_prepare(cpu);
break;
case CPU_UP_CANCELED:
case CPU_DEAD:
amd_uncore_cpu_dead(cpu);
break;
default:
break;
}
return NOTIFY_OK;
}
static struct notifier_block amd_uncore_cpu_notifier_block = {
.notifier_call = amd_uncore_cpu_notifier,
.priority = CPU_PRI_PERF + 1,
};
static void __init init_cpu_already_online(void *dummy)
{
unsigned int cpu = smp_processor_id();
amd_uncore_cpu_starting(cpu);
amd_uncore_cpu_online(cpu);
}
static void cleanup_cpu_online(void *dummy)
{
unsigned int cpu = smp_processor_id();
amd_uncore_cpu_dead(cpu);
}
static int __init amd_uncore_init(void)
{
unsigned int cpu, cpu2;
int ret = -ENODEV;
if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
goto fail_nodev;
if (!cpu_has_topoext)
goto fail_nodev;
if (cpu_has_perfctr_nb) {
amd_uncore_nb = alloc_percpu(struct amd_uncore *);
if (!amd_uncore_nb) {
ret = -ENOMEM;
goto fail_nb;
}
ret = perf_pmu_register(&amd_nb_pmu, amd_nb_pmu.name, -1);
if (ret)
goto fail_nb;
printk(KERN_INFO "perf: AMD NB counters detected\n");
ret = 0;
}
if (cpu_has_perfctr_l2) {
amd_uncore_l2 = alloc_percpu(struct amd_uncore *);
if (!amd_uncore_l2) {
ret = -ENOMEM;
goto fail_l2;
}
ret = perf_pmu_register(&amd_l2_pmu, amd_l2_pmu.name, -1);
if (ret)
goto fail_l2;
printk(KERN_INFO "perf: AMD L2I counters detected\n");
ret = 0;
}
if (ret)
goto fail_nodev;
cpu_notifier_register_begin();
/* init cpus already online before registering for hotplug notifier */
for_each_online_cpu(cpu) {
ret = amd_uncore_cpu_up_prepare(cpu);
if (ret)
goto fail_online;
smp_call_function_single(cpu, init_cpu_already_online, NULL, 1);
}
__register_cpu_notifier(&amd_uncore_cpu_notifier_block);
cpu_notifier_register_done();
return 0;
fail_online:
for_each_online_cpu(cpu2) {
if (cpu2 == cpu)
break;
smp_call_function_single(cpu, cleanup_cpu_online, NULL, 1);
}
cpu_notifier_register_done();
/* amd_uncore_nb/l2 should have been freed by cleanup_cpu_online */
amd_uncore_nb = amd_uncore_l2 = NULL;
if (cpu_has_perfctr_l2)
perf_pmu_unregister(&amd_l2_pmu);
fail_l2:
if (cpu_has_perfctr_nb)
perf_pmu_unregister(&amd_nb_pmu);
if (amd_uncore_l2)
free_percpu(amd_uncore_l2);
fail_nb:
if (amd_uncore_nb)
free_percpu(amd_uncore_nb);
fail_nodev:
return ret;
}
device_initcall(amd_uncore_init);