swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 9cb1fd0efd195590b828b9b865421ad345a4a145 authored by Linus Torvalds on 24 May 2020, 22:32:54 UTC
Linux 5.7-rc7
Linux 5.7-rc7
Tip revision: 9cb1fd0
uncore.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013 Advanced Micro Devices, Inc.
*
* Author: Jacob Shin <jacob.shin@amd.com>
*/
#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>
#include <asm/smp.h>
#define NUM_COUNTERS_NB 4
#define NUM_COUNTERS_L2 4
#define NUM_COUNTERS_L3 6
#define MAX_COUNTERS 6
#define RDPMC_BASE_NB 6
#define RDPMC_BASE_LLC 10
#define COUNTER_SHIFT 16
#undef pr_fmt
#define pr_fmt(fmt) "amd_uncore: " fmt
static int num_counters_llc;
static int num_counters_nb;
static bool l3_mask;
static HLIST_HEAD(uncore_unused_list);
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 hlist_node node;
};
static struct amd_uncore * __percpu *amd_uncore_nb;
static struct amd_uncore * __percpu *amd_uncore_llc;
static struct pmu amd_nb_pmu;
static struct pmu amd_llc_pmu;
static cpumask_t amd_nb_active_mask;
static cpumask_t amd_llc_active_mask;
static bool is_nb_event(struct perf_event *event)
{
return event->pmu->type == amd_nb_pmu.type;
}
static bool is_llc_event(struct perf_event *event)
{
return event->pmu->type == amd_llc_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_llc_event(event) && amd_uncore_llc)
return *per_cpu_ptr(amd_uncore_llc, 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;
}
/*
* Convert logical CPU number to L3 PMC Config ThreadMask format
*/
static u64 l3_thread_slice_mask(int cpu)
{
u64 thread_mask, core = topology_core_id(cpu);
unsigned int shift, thread = 0;
if (topology_smt_supported() && !topology_is_primary_thread(cpu))
thread = 1;
if (boot_cpu_data.x86 <= 0x18) {
shift = AMD64_L3_THREAD_SHIFT + 2 * (core % 4) + thread;
thread_mask = BIT_ULL(shift);
return AMD64_L3_SLICE_MASK | thread_mask;
}
core = (core << AMD64_L3_COREID_SHIFT) & AMD64_L3_COREID_MASK;
shift = AMD64_L3_THREAD_SHIFT + thread;
thread_mask = BIT_ULL(shift);
return AMD64_L3_EN_ALL_SLICES | core | thread_mask;
}
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 Last level cache counters (MSRs) are shared across all cores
* that share the same NB / Last level cache. On family 16h and below,
* 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 via
* CAP_NO_INTERRUPT, 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;
/*
* SliceMask and ThreadMask need to be set for certain L3 events.
* For other events, the two fields do not affect the count.
*/
if (l3_mask && is_llc_event(event))
hwc->config |= l3_thread_slice_mask(event->cpu);
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)
{
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_llc_pmu.type)
active_mask = &amd_llc_active_mask;
else
return 0;
return cpumap_print_to_pagebuf(true, buf, active_mask);
}
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,
};
/*
* Similar to PMU_FORMAT_ATTR but allowing for format_attr to be assigned based
* on family
*/
#define AMD_FORMAT_ATTR(_dev, _name, _format) \
static ssize_t \
_dev##_show##_name(struct device *dev, \
struct device_attribute *attr, \
char *page) \
{ \
BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE); \
return sprintf(page, _format "\n"); \
} \
static struct device_attribute format_attr_##_dev##_name = __ATTR_RO(_dev);
/* Used for each uncore counter type */
#define AMD_ATTRIBUTE(_name) \
static struct attribute *amd_uncore_format_attr_##_name[] = { \
&format_attr_event_##_name.attr, \
&format_attr_umask.attr, \
NULL, \
}; \
static struct attribute_group amd_uncore_format_group_##_name = { \
.name = "format", \
.attrs = amd_uncore_format_attr_##_name, \
}; \
static const struct attribute_group *amd_uncore_attr_groups_##_name[] = { \
&amd_uncore_attr_group, \
&amd_uncore_format_group_##_name, \
NULL, \
};
AMD_FORMAT_ATTR(event, , "config:0-7,32-35");
AMD_FORMAT_ATTR(umask, , "config:8-15");
AMD_FORMAT_ATTR(event, _df, "config:0-7,32-35,59-60");
AMD_FORMAT_ATTR(event, _l3, "config:0-7");
AMD_ATTRIBUTE(df);
AMD_ATTRIBUTE(l3);
static struct pmu amd_nb_pmu = {
.task_ctx_nr = perf_invalid_context,
.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,
.capabilities = PERF_PMU_CAP_NO_EXCLUDE | PERF_PMU_CAP_NO_INTERRUPT,
};
static struct pmu amd_llc_pmu = {
.task_ctx_nr = perf_invalid_context,
.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,
.capabilities = PERF_PMU_CAP_NO_EXCLUDE | PERF_PMU_CAP_NO_INTERRUPT,
};
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_llc;
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;
uncore_nb->id = -1;
*per_cpu_ptr(amd_uncore_nb, cpu) = uncore_nb;
}
if (amd_uncore_llc) {
uncore_llc = amd_uncore_alloc(cpu);
if (!uncore_llc)
goto fail;
uncore_llc->cpu = cpu;
uncore_llc->num_counters = num_counters_llc;
uncore_llc->rdpmc_base = RDPMC_BASE_LLC;
uncore_llc->msr_base = MSR_F16H_L2I_PERF_CTL;
uncore_llc->active_mask = &amd_llc_active_mask;
uncore_llc->pmu = &amd_llc_pmu;
uncore_llc->id = -1;
*per_cpu_ptr(amd_uncore_llc, cpu) = uncore_llc;
}
return 0;
fail:
if (amd_uncore_nb)
*per_cpu_ptr(amd_uncore_nb, cpu) = NULL;
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) {
hlist_add_head(&this->node, &uncore_unused_list);
this = that;
break;
}
}
this->refcnt++;
return this;
}
static int 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_llc) {
uncore = *per_cpu_ptr(amd_uncore_llc, cpu);
uncore->id = per_cpu(cpu_llc_id, cpu);
uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_llc);
*per_cpu_ptr(amd_uncore_llc, cpu) = uncore;
}
return 0;
}
static void uncore_clean_online(void)
{
struct amd_uncore *uncore;
struct hlist_node *n;
hlist_for_each_entry_safe(uncore, n, &uncore_unused_list, node) {
hlist_del(&uncore->node);
kfree(uncore);
}
}
static void uncore_online(unsigned int cpu,
struct amd_uncore * __percpu *uncores)
{
struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu);
uncore_clean_online();
if (cpu == uncore->cpu)
cpumask_set_cpu(cpu, uncore->active_mask);
}
static int amd_uncore_cpu_online(unsigned int cpu)
{
if (amd_uncore_nb)
uncore_online(cpu, amd_uncore_nb);
if (amd_uncore_llc)
uncore_online(cpu, amd_uncore_llc);
return 0;
}
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 int amd_uncore_cpu_down_prepare(unsigned int cpu)
{
if (amd_uncore_nb)
uncore_down_prepare(cpu, amd_uncore_nb);
if (amd_uncore_llc)
uncore_down_prepare(cpu, amd_uncore_llc);
return 0;
}
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 int amd_uncore_cpu_dead(unsigned int cpu)
{
if (amd_uncore_nb)
uncore_dead(cpu, amd_uncore_nb);
if (amd_uncore_llc)
uncore_dead(cpu, amd_uncore_llc);
return 0;
}
static int __init amd_uncore_init(void)
{
int ret = -ENODEV;
if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
return -ENODEV;
if (!boot_cpu_has(X86_FEATURE_TOPOEXT))
return -ENODEV;
if (boot_cpu_data.x86 >= 0x17) {
/*
* For F17h and above, the Northbridge counters are
* repurposed as Data Fabric counters. Also, L3
* counters are supported too. The PMUs are exported
* based on family as either L2 or L3 and NB or DF.
*/
num_counters_nb = NUM_COUNTERS_NB;
num_counters_llc = NUM_COUNTERS_L3;
amd_nb_pmu.name = "amd_df";
amd_llc_pmu.name = "amd_l3";
format_attr_event_df.show = &event_show_df;
format_attr_event_l3.show = &event_show_l3;
l3_mask = true;
} else {
num_counters_nb = NUM_COUNTERS_NB;
num_counters_llc = NUM_COUNTERS_L2;
amd_nb_pmu.name = "amd_nb";
amd_llc_pmu.name = "amd_l2";
format_attr_event_df = format_attr_event;
format_attr_event_l3 = format_attr_event;
l3_mask = false;
}
amd_nb_pmu.attr_groups = amd_uncore_attr_groups_df;
amd_llc_pmu.attr_groups = amd_uncore_attr_groups_l3;
if (boot_cpu_has(X86_FEATURE_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;
pr_info("%s NB counters detected\n",
boot_cpu_data.x86_vendor == X86_VENDOR_HYGON ?
"HYGON" : "AMD");
ret = 0;
}
if (boot_cpu_has(X86_FEATURE_PERFCTR_LLC)) {
amd_uncore_llc = alloc_percpu(struct amd_uncore *);
if (!amd_uncore_llc) {
ret = -ENOMEM;
goto fail_llc;
}
ret = perf_pmu_register(&amd_llc_pmu, amd_llc_pmu.name, -1);
if (ret)
goto fail_llc;
pr_info("%s LLC counters detected\n",
boot_cpu_data.x86_vendor == X86_VENDOR_HYGON ?
"HYGON" : "AMD");
ret = 0;
}
/*
* Install callbacks. Core will call them for each online cpu.
*/
if (cpuhp_setup_state(CPUHP_PERF_X86_AMD_UNCORE_PREP,
"perf/x86/amd/uncore:prepare",
amd_uncore_cpu_up_prepare, amd_uncore_cpu_dead))
goto fail_llc;
if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
"perf/x86/amd/uncore:starting",
amd_uncore_cpu_starting, NULL))
goto fail_prep;
if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
"perf/x86/amd/uncore:online",
amd_uncore_cpu_online,
amd_uncore_cpu_down_prepare))
goto fail_start;
return 0;
fail_start:
cpuhp_remove_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING);
fail_prep:
cpuhp_remove_state(CPUHP_PERF_X86_AMD_UNCORE_PREP);
fail_llc:
if (boot_cpu_has(X86_FEATURE_PERFCTR_NB))
perf_pmu_unregister(&amd_nb_pmu);
if (amd_uncore_llc)
free_percpu(amd_uncore_llc);
fail_nb:
if (amd_uncore_nb)
free_percpu(amd_uncore_nb);
return ret;
}
device_initcall(amd_uncore_init);