linux/drivers/dma/idxd/perfmon.c

663 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2020 Intel Corporation. All rights rsvd. */
#include <linux/sched/task.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include "idxd.h"
#include "perfmon.h"
static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
char *buf);
static cpumask_t perfmon_dsa_cpu_mask;
static bool cpuhp_set_up;
static enum cpuhp_state cpuhp_slot;
/*
* perf userspace reads this attribute to determine which cpus to open
* counters on. It's connected to perfmon_dsa_cpu_mask, which is
* maintained by the cpu hotplug handlers.
*/
static DEVICE_ATTR_RO(cpumask);
static struct attribute *perfmon_cpumask_attrs[] = {
&dev_attr_cpumask.attr,
NULL,
};
static struct attribute_group cpumask_attr_group = {
.attrs = perfmon_cpumask_attrs,
};
/*
* These attributes specify the bits in the config word that the perf
* syscall uses to pass the event ids and categories to perfmon.
*/
DEFINE_PERFMON_FORMAT_ATTR(event_category, "config:0-3");
DEFINE_PERFMON_FORMAT_ATTR(event, "config:4-31");
/*
* These attributes specify the bits in the config1 word that the perf
* syscall uses to pass filter data to perfmon.
*/
DEFINE_PERFMON_FORMAT_ATTR(filter_wq, "config1:0-31");
DEFINE_PERFMON_FORMAT_ATTR(filter_tc, "config1:32-39");
DEFINE_PERFMON_FORMAT_ATTR(filter_pgsz, "config1:40-43");
DEFINE_PERFMON_FORMAT_ATTR(filter_sz, "config1:44-51");
DEFINE_PERFMON_FORMAT_ATTR(filter_eng, "config1:52-59");
#define PERFMON_FILTERS_START 2
#define PERFMON_FILTERS_MAX 5
static struct attribute *perfmon_format_attrs[] = {
&format_attr_idxd_event_category.attr,
&format_attr_idxd_event.attr,
&format_attr_idxd_filter_wq.attr,
&format_attr_idxd_filter_tc.attr,
&format_attr_idxd_filter_pgsz.attr,
&format_attr_idxd_filter_sz.attr,
&format_attr_idxd_filter_eng.attr,
NULL,
};
static struct attribute_group perfmon_format_attr_group = {
.name = "format",
.attrs = perfmon_format_attrs,
};
static const struct attribute_group *perfmon_attr_groups[] = {
&perfmon_format_attr_group,
&cpumask_attr_group,
NULL,
};
static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return cpumap_print_to_pagebuf(true, buf, &perfmon_dsa_cpu_mask);
}
static bool is_idxd_event(struct idxd_pmu *idxd_pmu, struct perf_event *event)
{
return &idxd_pmu->pmu == event->pmu;
}
static int perfmon_collect_events(struct idxd_pmu *idxd_pmu,
struct perf_event *leader,
bool do_grp)
{
struct perf_event *event;
int n, max_count;
max_count = idxd_pmu->n_counters;
n = idxd_pmu->n_events;
if (n >= max_count)
return -EINVAL;
if (is_idxd_event(idxd_pmu, leader)) {
idxd_pmu->event_list[n] = leader;
idxd_pmu->event_list[n]->hw.idx = n;
n++;
}
if (!do_grp)
return n;
for_each_sibling_event(event, leader) {
if (!is_idxd_event(idxd_pmu, event) ||
event->state <= PERF_EVENT_STATE_OFF)
continue;
if (n >= max_count)
return -EINVAL;
idxd_pmu->event_list[n] = event;
idxd_pmu->event_list[n]->hw.idx = n;
n++;
}
return n;
}
static void perfmon_assign_hw_event(struct idxd_pmu *idxd_pmu,
struct perf_event *event, int idx)
{
struct idxd_device *idxd = idxd_pmu->idxd;
struct hw_perf_event *hwc = &event->hw;
hwc->idx = idx;
hwc->config_base = ioread64(CNTRCFG_REG(idxd, idx));
hwc->event_base = ioread64(CNTRCFG_REG(idxd, idx));
}
static int perfmon_assign_event(struct idxd_pmu *idxd_pmu,
struct perf_event *event)
{
int i;
for (i = 0; i < IDXD_PMU_EVENT_MAX; i++)
if (!test_and_set_bit(i, idxd_pmu->used_mask))
return i;
return -EINVAL;
}
/*
* Check whether there are enough counters to satisfy that all the
* events in the group can actually be scheduled at the same time.
*
* To do this, create a fake idxd_pmu object so the event collection
* and assignment functions can be used without affecting the internal
* state of the real idxd_pmu object.
*/
static int perfmon_validate_group(struct idxd_pmu *pmu,
struct perf_event *event)
{
struct perf_event *leader = event->group_leader;
struct idxd_pmu *fake_pmu;
int i, ret = 0, n, idx;
fake_pmu = kzalloc(sizeof(*fake_pmu), GFP_KERNEL);
if (!fake_pmu)
return -ENOMEM;
fake_pmu->pmu.name = pmu->pmu.name;
fake_pmu->n_counters = pmu->n_counters;
n = perfmon_collect_events(fake_pmu, leader, true);
if (n < 0) {
ret = n;
goto out;
}
fake_pmu->n_events = n;
n = perfmon_collect_events(fake_pmu, event, false);
if (n < 0) {
ret = n;
goto out;
}
fake_pmu->n_events = n;
for (i = 0; i < n; i++) {
event = fake_pmu->event_list[i];
idx = perfmon_assign_event(fake_pmu, event);
if (idx < 0) {
ret = idx;
goto out;
}
}
out:
kfree(fake_pmu);
return ret;
}
static int perfmon_pmu_event_init(struct perf_event *event)
{
struct idxd_device *idxd;
int ret = 0;
idxd = event_to_idxd(event);
event->hw.idx = -1;
if (event->attr.type != event->pmu->type)
return -ENOENT;
/* sampling not supported */
if (event->attr.sample_period)
return -EINVAL;
if (event->cpu < 0)
return -EINVAL;
if (event->pmu != &idxd->idxd_pmu->pmu)
return -EINVAL;
event->hw.event_base = ioread64(PERFMON_TABLE_OFFSET(idxd));
event->cpu = idxd->idxd_pmu->cpu;
event->hw.config = event->attr.config;
if (event->group_leader != event)
/* non-group events have themselves as leader */
ret = perfmon_validate_group(idxd->idxd_pmu, event);
return ret;
}
static inline u64 perfmon_pmu_read_counter(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
struct idxd_device *idxd;
int cntr = hwc->idx;
idxd = event_to_idxd(event);
return ioread64(CNTRDATA_REG(idxd, cntr));
}
static void perfmon_pmu_event_update(struct perf_event *event)
{
struct idxd_device *idxd = event_to_idxd(event);
u64 prev_raw_count, new_raw_count, delta, p, n;
int shift = 64 - idxd->idxd_pmu->counter_width;
struct hw_perf_event *hwc = &event->hw;
do {
prev_raw_count = local64_read(&hwc->prev_count);
new_raw_count = perfmon_pmu_read_counter(event);
} while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
new_raw_count) != prev_raw_count);
n = (new_raw_count << shift);
p = (prev_raw_count << shift);
delta = ((n - p) >> shift);
local64_add(delta, &event->count);
}
void perfmon_counter_overflow(struct idxd_device *idxd)
{
int i, n_counters, max_loop = OVERFLOW_SIZE;
struct perf_event *event;
unsigned long ovfstatus;
n_counters = min(idxd->idxd_pmu->n_counters, OVERFLOW_SIZE);
ovfstatus = ioread32(OVFSTATUS_REG(idxd));
/*
* While updating overflowed counters, other counters behind
* them could overflow and be missed in a given pass.
* Normally this could happen at most n_counters times, but in
* theory a tiny counter width could result in continual
* overflows and endless looping. max_loop provides a
* failsafe in that highly unlikely case.
*/
while (ovfstatus && max_loop--) {
/* Figure out which counter(s) overflowed */
for_each_set_bit(i, &ovfstatus, n_counters) {
unsigned long ovfstatus_clear = 0;
/* Update event->count for overflowed counter */
event = idxd->idxd_pmu->event_list[i];
perfmon_pmu_event_update(event);
/* Writing 1 to OVFSTATUS bit clears it */
set_bit(i, &ovfstatus_clear);
iowrite32(ovfstatus_clear, OVFSTATUS_REG(idxd));
}
ovfstatus = ioread32(OVFSTATUS_REG(idxd));
}
/*
* Should never happen. If so, it means a counter(s) looped
* around twice while this handler was running.
*/
WARN_ON_ONCE(ovfstatus);
}
static inline void perfmon_reset_config(struct idxd_device *idxd)
{
iowrite32(CONFIG_RESET, PERFRST_REG(idxd));
iowrite32(0, OVFSTATUS_REG(idxd));
iowrite32(0, PERFFRZ_REG(idxd));
}
static inline void perfmon_reset_counters(struct idxd_device *idxd)
{
iowrite32(CNTR_RESET, PERFRST_REG(idxd));
}
static inline void perfmon_reset(struct idxd_device *idxd)
{
perfmon_reset_config(idxd);
perfmon_reset_counters(idxd);
}
static void perfmon_pmu_event_start(struct perf_event *event, int mode)
{
u32 flt_wq, flt_tc, flt_pg_sz, flt_xfer_sz, flt_eng = 0;
u64 cntr_cfg, cntrdata, event_enc, event_cat = 0;
struct hw_perf_event *hwc = &event->hw;
union filter_cfg flt_cfg;
union event_cfg event_cfg;
struct idxd_device *idxd;
int cntr;
idxd = event_to_idxd(event);
event->hw.idx = hwc->idx;
cntr = hwc->idx;
/* Obtain event category and event value from user space */
event_cfg.val = event->attr.config;
flt_cfg.val = event->attr.config1;
event_cat = event_cfg.event_cat;
event_enc = event_cfg.event_enc;
/* Obtain filter configuration from user space */
flt_wq = flt_cfg.wq;
flt_tc = flt_cfg.tc;
flt_pg_sz = flt_cfg.pg_sz;
flt_xfer_sz = flt_cfg.xfer_sz;
flt_eng = flt_cfg.eng;
if (flt_wq && test_bit(FLT_WQ, &idxd->idxd_pmu->supported_filters))
iowrite32(flt_wq, FLTCFG_REG(idxd, cntr, FLT_WQ));
if (flt_tc && test_bit(FLT_TC, &idxd->idxd_pmu->supported_filters))
iowrite32(flt_tc, FLTCFG_REG(idxd, cntr, FLT_TC));
if (flt_pg_sz && test_bit(FLT_PG_SZ, &idxd->idxd_pmu->supported_filters))
iowrite32(flt_pg_sz, FLTCFG_REG(idxd, cntr, FLT_PG_SZ));
if (flt_xfer_sz && test_bit(FLT_XFER_SZ, &idxd->idxd_pmu->supported_filters))
iowrite32(flt_xfer_sz, FLTCFG_REG(idxd, cntr, FLT_XFER_SZ));
if (flt_eng && test_bit(FLT_ENG, &idxd->idxd_pmu->supported_filters))
iowrite32(flt_eng, FLTCFG_REG(idxd, cntr, FLT_ENG));
/* Read the start value */
cntrdata = ioread64(CNTRDATA_REG(idxd, cntr));
local64_set(&event->hw.prev_count, cntrdata);
/* Set counter to event/category */
cntr_cfg = event_cat << CNTRCFG_CATEGORY_SHIFT;
cntr_cfg |= event_enc << CNTRCFG_EVENT_SHIFT;
/* Set interrupt on overflow and counter enable bits */
cntr_cfg |= (CNTRCFG_IRQ_OVERFLOW | CNTRCFG_ENABLE);
iowrite64(cntr_cfg, CNTRCFG_REG(idxd, cntr));
}
static void perfmon_pmu_event_stop(struct perf_event *event, int mode)
{
struct hw_perf_event *hwc = &event->hw;
struct idxd_device *idxd;
int i, cntr = hwc->idx;
u64 cntr_cfg;
idxd = event_to_idxd(event);
/* remove this event from event list */
for (i = 0; i < idxd->idxd_pmu->n_events; i++) {
if (event != idxd->idxd_pmu->event_list[i])
continue;
for (++i; i < idxd->idxd_pmu->n_events; i++)
idxd->idxd_pmu->event_list[i - 1] = idxd->idxd_pmu->event_list[i];
--idxd->idxd_pmu->n_events;
break;
}
cntr_cfg = ioread64(CNTRCFG_REG(idxd, cntr));
cntr_cfg &= ~CNTRCFG_ENABLE;
iowrite64(cntr_cfg, CNTRCFG_REG(idxd, cntr));
if (mode == PERF_EF_UPDATE)
perfmon_pmu_event_update(event);
event->hw.idx = -1;
clear_bit(cntr, idxd->idxd_pmu->used_mask);
}
static void perfmon_pmu_event_del(struct perf_event *event, int mode)
{
perfmon_pmu_event_stop(event, PERF_EF_UPDATE);
}
static int perfmon_pmu_event_add(struct perf_event *event, int flags)
{
struct idxd_device *idxd = event_to_idxd(event);
struct idxd_pmu *idxd_pmu = idxd->idxd_pmu;
struct hw_perf_event *hwc = &event->hw;
int idx, n;
n = perfmon_collect_events(idxd_pmu, event, false);
if (n < 0)
return n;
hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
if (!(flags & PERF_EF_START))
hwc->state |= PERF_HES_ARCH;
idx = perfmon_assign_event(idxd_pmu, event);
if (idx < 0)
return idx;
perfmon_assign_hw_event(idxd_pmu, event, idx);
if (flags & PERF_EF_START)
perfmon_pmu_event_start(event, 0);
idxd_pmu->n_events = n;
return 0;
}
static void enable_perfmon_pmu(struct idxd_device *idxd)
{
iowrite32(COUNTER_UNFREEZE, PERFFRZ_REG(idxd));
}
static void disable_perfmon_pmu(struct idxd_device *idxd)
{
iowrite32(COUNTER_FREEZE, PERFFRZ_REG(idxd));
}
static void perfmon_pmu_enable(struct pmu *pmu)
{
struct idxd_device *idxd = pmu_to_idxd(pmu);
enable_perfmon_pmu(idxd);
}
static void perfmon_pmu_disable(struct pmu *pmu)
{
struct idxd_device *idxd = pmu_to_idxd(pmu);
disable_perfmon_pmu(idxd);
}
static void skip_filter(int i)
{
int j;
for (j = i; j < PERFMON_FILTERS_MAX; j++)
perfmon_format_attrs[PERFMON_FILTERS_START + j] =
perfmon_format_attrs[PERFMON_FILTERS_START + j + 1];
}
static void idxd_pmu_init(struct idxd_pmu *idxd_pmu)
{
int i;
for (i = 0 ; i < PERFMON_FILTERS_MAX; i++) {
if (!test_bit(i, &idxd_pmu->supported_filters))
skip_filter(i);
}
idxd_pmu->pmu.name = idxd_pmu->name;
idxd_pmu->pmu.attr_groups = perfmon_attr_groups;
idxd_pmu->pmu.task_ctx_nr = perf_invalid_context;
idxd_pmu->pmu.event_init = perfmon_pmu_event_init;
idxd_pmu->pmu.pmu_enable = perfmon_pmu_enable,
idxd_pmu->pmu.pmu_disable = perfmon_pmu_disable,
idxd_pmu->pmu.add = perfmon_pmu_event_add;
idxd_pmu->pmu.del = perfmon_pmu_event_del;
idxd_pmu->pmu.start = perfmon_pmu_event_start;
idxd_pmu->pmu.stop = perfmon_pmu_event_stop;
idxd_pmu->pmu.read = perfmon_pmu_event_update;
idxd_pmu->pmu.capabilities = PERF_PMU_CAP_NO_EXCLUDE;
idxd_pmu->pmu.module = THIS_MODULE;
}
void perfmon_pmu_remove(struct idxd_device *idxd)
{
if (!idxd->idxd_pmu)
return;
cpuhp_state_remove_instance(cpuhp_slot, &idxd->idxd_pmu->cpuhp_node);
perf_pmu_unregister(&idxd->idxd_pmu->pmu);
kfree(idxd->idxd_pmu);
idxd->idxd_pmu = NULL;
}
static int perf_event_cpu_online(unsigned int cpu, struct hlist_node *node)
{
struct idxd_pmu *idxd_pmu;
idxd_pmu = hlist_entry_safe(node, typeof(*idxd_pmu), cpuhp_node);
/* select the first online CPU as the designated reader */
if (cpumask_empty(&perfmon_dsa_cpu_mask)) {
cpumask_set_cpu(cpu, &perfmon_dsa_cpu_mask);
idxd_pmu->cpu = cpu;
}
return 0;
}
static int perf_event_cpu_offline(unsigned int cpu, struct hlist_node *node)
{
struct idxd_pmu *idxd_pmu;
unsigned int target;
idxd_pmu = hlist_entry_safe(node, typeof(*idxd_pmu), cpuhp_node);
if (!cpumask_test_and_clear_cpu(cpu, &perfmon_dsa_cpu_mask))
return 0;
target = cpumask_any_but(cpu_online_mask, cpu);
/* migrate events if there is a valid target */
if (target < nr_cpu_ids)
cpumask_set_cpu(target, &perfmon_dsa_cpu_mask);
else
target = -1;
perf_pmu_migrate_context(&idxd_pmu->pmu, cpu, target);
return 0;
}
int perfmon_pmu_init(struct idxd_device *idxd)
{
union idxd_perfcap perfcap;
struct idxd_pmu *idxd_pmu;
int rc = -ENODEV;
/*
* perfmon module initialization failed, nothing to do
*/
if (!cpuhp_set_up)
return -ENODEV;
/*
* If perfmon_offset or num_counters is 0, it means perfmon is
* not supported on this hardware.
*/
if (idxd->perfmon_offset == 0)
return -ENODEV;
idxd_pmu = kzalloc(sizeof(*idxd_pmu), GFP_KERNEL);
if (!idxd_pmu)
return -ENOMEM;
idxd_pmu->idxd = idxd;
idxd->idxd_pmu = idxd_pmu;
if (idxd->data->type == IDXD_TYPE_DSA) {
rc = sprintf(idxd_pmu->name, "dsa%d", idxd->id);
if (rc < 0)
goto free;
} else if (idxd->data->type == IDXD_TYPE_IAX) {
rc = sprintf(idxd_pmu->name, "iax%d", idxd->id);
if (rc < 0)
goto free;
} else {
goto free;
}
perfmon_reset(idxd);
perfcap.bits = ioread64(PERFCAP_REG(idxd));
/*
* If total perf counter is 0, stop further registration.
* This is necessary in order to support driver running on
* guest which does not have pmon support.
*/
if (perfcap.num_perf_counter == 0)
goto free;
/* A counter width of 0 means it can't count */
if (perfcap.counter_width == 0)
goto free;
/* Overflow interrupt and counter freeze support must be available */
if (!perfcap.overflow_interrupt || !perfcap.counter_freeze)
goto free;
/* Number of event categories cannot be 0 */
if (perfcap.num_event_category == 0)
goto free;
/*
* We don't support per-counter capabilities for now.
*/
if (perfcap.cap_per_counter)
goto free;
idxd_pmu->n_event_categories = perfcap.num_event_category;
idxd_pmu->supported_event_categories = perfcap.global_event_category;
idxd_pmu->per_counter_caps_supported = perfcap.cap_per_counter;
/* check filter capability. If 0, then filters are not supported */
idxd_pmu->supported_filters = perfcap.filter;
if (perfcap.filter)
idxd_pmu->n_filters = hweight8(perfcap.filter);
/* Store the total number of counters categories, and counter width */
idxd_pmu->n_counters = perfcap.num_perf_counter;
idxd_pmu->counter_width = perfcap.counter_width;
idxd_pmu_init(idxd_pmu);
rc = perf_pmu_register(&idxd_pmu->pmu, idxd_pmu->name, -1);
if (rc)
goto free;
rc = cpuhp_state_add_instance(cpuhp_slot, &idxd_pmu->cpuhp_node);
if (rc) {
perf_pmu_unregister(&idxd->idxd_pmu->pmu);
goto free;
}
out:
return rc;
free:
kfree(idxd_pmu);
idxd->idxd_pmu = NULL;
goto out;
}
void __init perfmon_init(void)
{
int rc = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
"driver/dma/idxd/perf:online",
perf_event_cpu_online,
perf_event_cpu_offline);
if (WARN_ON(rc < 0))
return;
cpuhp_slot = rc;
cpuhp_set_up = true;
}
void __exit perfmon_exit(void)
{
if (cpuhp_set_up)
cpuhp_remove_multi_state(cpuhp_slot);
}