drivers/perf: imx_ddr: Add DDR performance counter support to perf
authorFrank Li <frank.li@nxp.com>
Wed, 1 May 2019 18:43:29 +0000 (18:43 +0000)
committerWill Deacon <will.deacon@arm.com>
Thu, 13 Jun 2019 10:07:57 +0000 (11:07 +0100)
Add DDR performance monitor support for iMX8QXP. The PMU consists of 3
programmable event counters and a single dedicated cycle counter.

Example usage:

 $ perf stat -a -e \
   imx8_ddr0/read-cycles/,imx8_ddr0/write-cycles/,imx8_ddr0/precharge/ ls

- or -

 $ perf stat -a -e \
   imx8_ddr0/cycles/,imx8_ddr0/read-access/,imx8_ddr0/write-access/ ls

Other events are supported, and advertised via perf list.

Reviewed-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[will: rewrote commit message/kconfig and used #defines for dev/cpuhp names]
Signed-off-by: Will Deacon <will.deacon@arm.com>
drivers/perf/Kconfig
drivers/perf/Makefile
drivers/perf/fsl_imx8_ddr_perf.c [new file with mode: 0644]

index e4221a1..09ae8a9 100644 (file)
@@ -71,6 +71,14 @@ config ARM_DSU_PMU
          system, control logic. The PMU allows counting various events related
          to DSU.
 
+config FSL_IMX8_DDR_PMU
+       tristate "Freescale i.MX8 DDR perf monitor"
+       depends on ARCH_MXC
+         help
+         Provides support for the DDR performance monitor in i.MX8, which
+         can give information about memory throughput and other related
+         events.
+
 config HISI_PMU
        bool "HiSilicon SoC PMU"
        depends on ARM64 && ACPI
index 3048994..2ebb4de 100644 (file)
@@ -5,6 +5,7 @@ obj-$(CONFIG_ARM_DSU_PMU) += arm_dsu_pmu.o
 obj-$(CONFIG_ARM_PMU) += arm_pmu.o arm_pmu_platform.o
 obj-$(CONFIG_ARM_PMU_ACPI) += arm_pmu_acpi.o
 obj-$(CONFIG_ARM_SMMU_V3_PMU) += arm_smmuv3_pmu.o
+obj-$(CONFIG_FSL_IMX8_DDR_PMU) += fsl_imx8_ddr_perf.o
 obj-$(CONFIG_HISI_PMU) += hisilicon/
 obj-$(CONFIG_QCOM_L2_PMU)      += qcom_l2_pmu.o
 obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
diff --git a/drivers/perf/fsl_imx8_ddr_perf.c b/drivers/perf/fsl_imx8_ddr_perf.c
new file mode 100644 (file)
index 0000000..63fe216
--- /dev/null
@@ -0,0 +1,554 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2017 NXP
+ * Copyright 2016 Freescale Semiconductor, Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/perf_event.h>
+#include <linux/slab.h>
+
+#define COUNTER_CNTL           0x0
+#define COUNTER_READ           0x20
+
+#define COUNTER_DPCR1          0x30
+
+#define CNTL_OVER              0x1
+#define CNTL_CLEAR             0x2
+#define CNTL_EN                        0x4
+#define CNTL_EN_MASK           0xFFFFFFFB
+#define CNTL_CLEAR_MASK                0xFFFFFFFD
+#define CNTL_OVER_MASK         0xFFFFFFFE
+
+#define CNTL_CSV_SHIFT         24
+#define CNTL_CSV_MASK          (0xFF << CNTL_CSV_SHIFT)
+
+#define EVENT_CYCLES_ID                0
+#define EVENT_CYCLES_COUNTER   0
+#define NUM_COUNTERS           4
+
+#define to_ddr_pmu(p)          container_of(p, struct ddr_pmu, pmu)
+
+#define DDR_PERF_DEV_NAME      "imx8_ddr"
+#define DDR_CPUHP_CB_NAME      DDR_PERF_DEV_NAME "_perf_pmu"
+
+static DEFINE_IDA(ddr_ida);
+
+static const struct of_device_id imx_ddr_pmu_dt_ids[] = {
+       { .compatible = "fsl,imx8-ddr-pmu",},
+       { .compatible = "fsl,imx8m-ddr-pmu",},
+       { /* sentinel */ }
+};
+
+struct ddr_pmu {
+       struct pmu pmu;
+       void __iomem *base;
+       unsigned int cpu;
+       struct  hlist_node node;
+       struct  device *dev;
+       struct perf_event *events[NUM_COUNTERS];
+       int active_events;
+       enum cpuhp_state cpuhp_state;
+       int irq;
+       int id;
+};
+
+static ssize_t ddr_perf_cpumask_show(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct ddr_pmu *pmu = dev_get_drvdata(dev);
+
+       return cpumap_print_to_pagebuf(true, buf, cpumask_of(pmu->cpu));
+}
+
+static struct device_attribute ddr_perf_cpumask_attr =
+       __ATTR(cpumask, 0444, ddr_perf_cpumask_show, NULL);
+
+static struct attribute *ddr_perf_cpumask_attrs[] = {
+       &ddr_perf_cpumask_attr.attr,
+       NULL,
+};
+
+static struct attribute_group ddr_perf_cpumask_attr_group = {
+       .attrs = ddr_perf_cpumask_attrs,
+};
+
+static ssize_t
+ddr_pmu_event_show(struct device *dev, struct device_attribute *attr,
+                  char *page)
+{
+       struct perf_pmu_events_attr *pmu_attr;
+
+       pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
+       return sprintf(page, "event=0x%02llx\n", pmu_attr->id);
+}
+
+#define IMX8_DDR_PMU_EVENT_ATTR(_name, _id)                            \
+       (&((struct perf_pmu_events_attr[]) {                            \
+               { .attr = __ATTR(_name, 0444, ddr_pmu_event_show, NULL),\
+                 .id = _id, }                                          \
+       })[0].attr.attr)
+
+static struct attribute *ddr_perf_events_attrs[] = {
+       IMX8_DDR_PMU_EVENT_ATTR(cycles, EVENT_CYCLES_ID),
+       IMX8_DDR_PMU_EVENT_ATTR(selfresh, 0x01),
+       IMX8_DDR_PMU_EVENT_ATTR(read-accesses, 0x04),
+       IMX8_DDR_PMU_EVENT_ATTR(write-accesses, 0x05),
+       IMX8_DDR_PMU_EVENT_ATTR(read-queue-depth, 0x08),
+       IMX8_DDR_PMU_EVENT_ATTR(write-queue-depth, 0x09),
+       IMX8_DDR_PMU_EVENT_ATTR(lp-read-credit-cnt, 0x10),
+       IMX8_DDR_PMU_EVENT_ATTR(hp-read-credit-cnt, 0x11),
+       IMX8_DDR_PMU_EVENT_ATTR(write-credit-cnt, 0x12),
+       IMX8_DDR_PMU_EVENT_ATTR(read-command, 0x20),
+       IMX8_DDR_PMU_EVENT_ATTR(write-command, 0x21),
+       IMX8_DDR_PMU_EVENT_ATTR(read-modify-write-command, 0x22),
+       IMX8_DDR_PMU_EVENT_ATTR(hp-read, 0x23),
+       IMX8_DDR_PMU_EVENT_ATTR(hp-req-nocredit, 0x24),
+       IMX8_DDR_PMU_EVENT_ATTR(hp-xact-credit, 0x25),
+       IMX8_DDR_PMU_EVENT_ATTR(lp-req-nocredit, 0x26),
+       IMX8_DDR_PMU_EVENT_ATTR(lp-xact-credit, 0x27),
+       IMX8_DDR_PMU_EVENT_ATTR(wr-xact-credit, 0x29),
+       IMX8_DDR_PMU_EVENT_ATTR(read-cycles, 0x2a),
+       IMX8_DDR_PMU_EVENT_ATTR(write-cycles, 0x2b),
+       IMX8_DDR_PMU_EVENT_ATTR(read-write-transition, 0x30),
+       IMX8_DDR_PMU_EVENT_ATTR(precharge, 0x31),
+       IMX8_DDR_PMU_EVENT_ATTR(activate, 0x32),
+       IMX8_DDR_PMU_EVENT_ATTR(load-mode, 0x33),
+       IMX8_DDR_PMU_EVENT_ATTR(perf-mwr, 0x34),
+       IMX8_DDR_PMU_EVENT_ATTR(read, 0x35),
+       IMX8_DDR_PMU_EVENT_ATTR(read-activate, 0x36),
+       IMX8_DDR_PMU_EVENT_ATTR(refresh, 0x37),
+       IMX8_DDR_PMU_EVENT_ATTR(write, 0x38),
+       IMX8_DDR_PMU_EVENT_ATTR(raw-hazard, 0x39),
+       NULL,
+};
+
+static struct attribute_group ddr_perf_events_attr_group = {
+       .name = "events",
+       .attrs = ddr_perf_events_attrs,
+};
+
+PMU_FORMAT_ATTR(event, "config:0-7");
+
+static struct attribute *ddr_perf_format_attrs[] = {
+       &format_attr_event.attr,
+       NULL,
+};
+
+static struct attribute_group ddr_perf_format_attr_group = {
+       .name = "format",
+       .attrs = ddr_perf_format_attrs,
+};
+
+static const struct attribute_group *attr_groups[] = {
+       &ddr_perf_events_attr_group,
+       &ddr_perf_format_attr_group,
+       &ddr_perf_cpumask_attr_group,
+       NULL,
+};
+
+static u32 ddr_perf_alloc_counter(struct ddr_pmu *pmu, int event)
+{
+       int i;
+
+       /*
+        * Always map cycle event to counter 0
+        * Cycles counter is dedicated for cycle event
+        * can't used for the other events
+        */
+       if (event == EVENT_CYCLES_ID) {
+               if (pmu->events[EVENT_CYCLES_COUNTER] == NULL)
+                       return EVENT_CYCLES_COUNTER;
+               else
+                       return -ENOENT;
+       }
+
+       for (i = 1; i < NUM_COUNTERS; i++) {
+               if (pmu->events[i] == NULL)
+                       return i;
+       }
+
+       return -ENOENT;
+}
+
+static void ddr_perf_free_counter(struct ddr_pmu *pmu, int counter)
+{
+       pmu->events[counter] = NULL;
+}
+
+static u32 ddr_perf_read_counter(struct ddr_pmu *pmu, int counter)
+{
+       return readl_relaxed(pmu->base + COUNTER_READ + counter * 4);
+}
+
+static int ddr_perf_event_init(struct perf_event *event)
+{
+       struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+       struct hw_perf_event *hwc = &event->hw;
+       struct perf_event *sibling;
+
+       if (event->attr.type != event->pmu->type)
+               return -ENOENT;
+
+       if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
+               return -EOPNOTSUPP;
+
+       if (event->cpu < 0) {
+               dev_warn(pmu->dev, "Can't provide per-task data!\n");
+               return -EOPNOTSUPP;
+       }
+
+       /*
+        * We must NOT create groups containing mixed PMUs, although software
+        * events are acceptable (for example to create a CCN group
+        * periodically read when a hrtimer aka cpu-clock leader triggers).
+        */
+       if (event->group_leader->pmu != event->pmu &&
+                       !is_software_event(event->group_leader))
+               return -EINVAL;
+
+       for_each_sibling_event(sibling, event->group_leader) {
+               if (sibling->pmu != event->pmu &&
+                               !is_software_event(sibling))
+                       return -EINVAL;
+       }
+
+       event->cpu = pmu->cpu;
+       hwc->idx = -1;
+
+       return 0;
+}
+
+
+static void ddr_perf_event_update(struct perf_event *event)
+{
+       struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+       struct hw_perf_event *hwc = &event->hw;
+       u64 delta, prev_raw_count, new_raw_count;
+       int counter = hwc->idx;
+
+       do {
+               prev_raw_count = local64_read(&hwc->prev_count);
+               new_raw_count = ddr_perf_read_counter(pmu, counter);
+       } while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
+                       new_raw_count) != prev_raw_count);
+
+       delta = (new_raw_count - prev_raw_count) & 0xFFFFFFFF;
+
+       local64_add(delta, &event->count);
+}
+
+static void ddr_perf_counter_enable(struct ddr_pmu *pmu, int config,
+                                 int counter, bool enable)
+{
+       u8 reg = counter * 4 + COUNTER_CNTL;
+       int val;
+
+       if (enable) {
+               /*
+                * must disable first, then enable again
+                * otherwise, cycle counter will not work
+                * if previous state is enabled.
+                */
+               writel(0, pmu->base + reg);
+               val = CNTL_EN | CNTL_CLEAR;
+               val |= FIELD_PREP(CNTL_CSV_MASK, config);
+               writel(val, pmu->base + reg);
+       } else {
+               /* Disable counter */
+               writel(0, pmu->base + reg);
+       }
+}
+
+static void ddr_perf_event_start(struct perf_event *event, int flags)
+{
+       struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+       struct hw_perf_event *hwc = &event->hw;
+       int counter = hwc->idx;
+
+       local64_set(&hwc->prev_count, 0);
+
+       ddr_perf_counter_enable(pmu, event->attr.config, counter, true);
+
+       hwc->state = 0;
+}
+
+static int ddr_perf_event_add(struct perf_event *event, int flags)
+{
+       struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+       struct hw_perf_event *hwc = &event->hw;
+       int counter;
+       int cfg = event->attr.config;
+
+       counter = ddr_perf_alloc_counter(pmu, cfg);
+       if (counter < 0) {
+               dev_dbg(pmu->dev, "There are not enough counters\n");
+               return -EOPNOTSUPP;
+       }
+
+       pmu->events[counter] = event;
+       pmu->active_events++;
+       hwc->idx = counter;
+
+       hwc->state |= PERF_HES_STOPPED;
+
+       if (flags & PERF_EF_START)
+               ddr_perf_event_start(event, flags);
+
+       return 0;
+}
+
+static void ddr_perf_event_stop(struct perf_event *event, int flags)
+{
+       struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+       struct hw_perf_event *hwc = &event->hw;
+       int counter = hwc->idx;
+
+       ddr_perf_counter_enable(pmu, event->attr.config, counter, false);
+       ddr_perf_event_update(event);
+
+       hwc->state |= PERF_HES_STOPPED;
+}
+
+static void ddr_perf_event_del(struct perf_event *event, int flags)
+{
+       struct ddr_pmu *pmu = to_ddr_pmu(event->pmu);
+       struct hw_perf_event *hwc = &event->hw;
+       int counter = hwc->idx;
+
+       ddr_perf_event_stop(event, PERF_EF_UPDATE);
+
+       ddr_perf_free_counter(pmu, counter);
+       pmu->active_events--;
+       hwc->idx = -1;
+}
+
+static void ddr_perf_pmu_enable(struct pmu *pmu)
+{
+       struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
+
+       /* enable cycle counter if cycle is not active event list */
+       if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
+               ddr_perf_counter_enable(ddr_pmu,
+                                     EVENT_CYCLES_ID,
+                                     EVENT_CYCLES_COUNTER,
+                                     true);
+}
+
+static void ddr_perf_pmu_disable(struct pmu *pmu)
+{
+       struct ddr_pmu *ddr_pmu = to_ddr_pmu(pmu);
+
+       if (ddr_pmu->events[EVENT_CYCLES_COUNTER] == NULL)
+               ddr_perf_counter_enable(ddr_pmu,
+                                     EVENT_CYCLES_ID,
+                                     EVENT_CYCLES_COUNTER,
+                                     false);
+}
+
+static int ddr_perf_init(struct ddr_pmu *pmu, void __iomem *base,
+                        struct device *dev)
+{
+       *pmu = (struct ddr_pmu) {
+               .pmu = (struct pmu) {
+                       .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
+                       .task_ctx_nr = perf_invalid_context,
+                       .attr_groups = attr_groups,
+                       .event_init  = ddr_perf_event_init,
+                       .add         = ddr_perf_event_add,
+                       .del         = ddr_perf_event_del,
+                       .start       = ddr_perf_event_start,
+                       .stop        = ddr_perf_event_stop,
+                       .read        = ddr_perf_event_update,
+                       .pmu_enable  = ddr_perf_pmu_enable,
+                       .pmu_disable = ddr_perf_pmu_disable,
+               },
+               .base = base,
+               .dev = dev,
+       };
+
+       pmu->id = ida_simple_get(&ddr_ida, 0, 0, GFP_KERNEL);
+       return pmu->id;
+}
+
+static irqreturn_t ddr_perf_irq_handler(int irq, void *p)
+{
+       int i;
+       struct ddr_pmu *pmu = (struct ddr_pmu *) p;
+       struct perf_event *event, *cycle_event = NULL;
+
+       /* all counter will stop if cycle counter disabled */
+       ddr_perf_counter_enable(pmu,
+                             EVENT_CYCLES_ID,
+                             EVENT_CYCLES_COUNTER,
+                             false);
+       /*
+        * When the cycle counter overflows, all counters are stopped,
+        * and an IRQ is raised. If any other counter overflows, it
+        * continues counting, and no IRQ is raised.
+        *
+        * Cycles occur at least 4 times as often as other events, so we
+        * can update all events on a cycle counter overflow and not
+        * lose events.
+        *
+        */
+       for (i = 0; i < NUM_COUNTERS; i++) {
+
+               if (!pmu->events[i])
+                       continue;
+
+               event = pmu->events[i];
+
+               ddr_perf_event_update(event);
+
+               if (event->hw.idx == EVENT_CYCLES_COUNTER)
+                       cycle_event = event;
+       }
+
+       ddr_perf_counter_enable(pmu,
+                             EVENT_CYCLES_ID,
+                             EVENT_CYCLES_COUNTER,
+                             true);
+       if (cycle_event)
+               ddr_perf_event_update(cycle_event);
+
+       return IRQ_HANDLED;
+}
+
+static int ddr_perf_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+       struct ddr_pmu *pmu = hlist_entry_safe(node, struct ddr_pmu, node);
+       int target;
+
+       if (cpu != pmu->cpu)
+               return 0;
+
+       target = cpumask_any_but(cpu_online_mask, cpu);
+       if (target >= nr_cpu_ids)
+               return 0;
+
+       perf_pmu_migrate_context(&pmu->pmu, cpu, target);
+       pmu->cpu = target;
+
+       WARN_ON(irq_set_affinity_hint(pmu->irq, cpumask_of(pmu->cpu)));
+
+       return 0;
+}
+
+static int ddr_perf_probe(struct platform_device *pdev)
+{
+       struct ddr_pmu *pmu;
+       struct device_node *np;
+       void __iomem *base;
+       char *name;
+       int num;
+       int ret;
+       int irq;
+
+       base = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(base))
+               return PTR_ERR(base);
+
+       np = pdev->dev.of_node;
+
+       pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL);
+       if (!pmu)
+               return -ENOMEM;
+
+       num = ddr_perf_init(pmu, base, &pdev->dev);
+
+       platform_set_drvdata(pdev, pmu);
+
+       name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME "%d",
+                             num);
+       if (!name)
+               return -ENOMEM;
+
+       pmu->cpu = raw_smp_processor_id();
+       ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
+                                     DDR_CPUHP_CB_NAME,
+                                     NULL,
+                                     ddr_perf_offline_cpu);
+
+       if (ret < 0) {
+               dev_err(&pdev->dev, "cpuhp_setup_state_multi failed\n");
+               goto ddr_perf_err;
+       }
+
+       pmu->cpuhp_state = ret;
+
+       /* Register the pmu instance for cpu hotplug */
+       cpuhp_state_add_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+
+       /* Request irq */
+       irq = of_irq_get(np, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "Failed to get irq: %d", irq);
+               ret = irq;
+               goto ddr_perf_err;
+       }
+
+       ret = devm_request_irq(&pdev->dev, irq,
+                                       ddr_perf_irq_handler,
+                                       IRQF_NOBALANCING | IRQF_NO_THREAD,
+                                       DDR_CPUHP_CB_NAME,
+                                       pmu);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "Request irq failed: %d", ret);
+               goto ddr_perf_err;
+       }
+
+       pmu->irq = irq;
+       ret = irq_set_affinity_hint(pmu->irq, cpumask_of(pmu->cpu));
+       if (ret) {
+               dev_err(pmu->dev, "Failed to set interrupt affinity!\n");
+               goto ddr_perf_err;
+       }
+
+       ret = perf_pmu_register(&pmu->pmu, name, -1);
+       if (ret)
+               goto ddr_perf_err;
+
+       return 0;
+
+ddr_perf_err:
+       if (pmu->cpuhp_state)
+               cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+
+       ida_simple_remove(&ddr_ida, pmu->id);
+       dev_warn(&pdev->dev, "i.MX8 DDR Perf PMU failed (%d), disabled\n", ret);
+       return ret;
+}
+
+static int ddr_perf_remove(struct platform_device *pdev)
+{
+       struct ddr_pmu *pmu = platform_get_drvdata(pdev);
+
+       cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
+       irq_set_affinity_hint(pmu->irq, NULL);
+
+       perf_pmu_unregister(&pmu->pmu);
+
+       ida_simple_remove(&ddr_ida, pmu->id);
+       return 0;
+}
+
+static struct platform_driver imx_ddr_pmu_driver = {
+       .driver         = {
+               .name   = "imx-ddr-pmu",
+               .of_match_table = imx_ddr_pmu_dt_ids,
+       },
+       .probe          = ddr_perf_probe,
+       .remove         = ddr_perf_remove,
+};
+
+module_platform_driver(imx_ddr_pmu_driver);
+MODULE_LICENSE("GPL v2");