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);
+}