diff options
Diffstat (limited to 'drivers/dma/idxd/perfmon.c')
| -rw-r--r-- | drivers/dma/idxd/perfmon.c | 662 |
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); +} |