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-rw-r--r--drivers/dma/idxd/perfmon.c662
1 files changed, 662 insertions, 0 deletions
diff --git a/drivers/dma/idxd/perfmon.c b/drivers/dma/idxd/perfmon.c
new file mode 100644
index 000000000..d73004f47
--- /dev/null
+++ b/drivers/dma/idxd/perfmon.c
@@ -0,0 +1,662 @@
+// 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);
+}