root/drivers/perf/marvell_cn10k_tad_pmu.c
// SPDX-License-Identifier: GPL-2.0
/* Marvell CN10K LLC-TAD perf driver
 *
 * Copyright (C) 2021 Marvell
 */

#define pr_fmt(fmt) "tad_pmu: " fmt

#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/cpuhotplug.h>
#include <linux/perf_event.h>
#include <linux/platform_device.h>
#include <linux/acpi.h>

#define TAD_PFC_OFFSET          0x800
#define TAD_PFC(counter)        (TAD_PFC_OFFSET | (counter << 3))
#define TAD_PRF_OFFSET          0x900
#define TAD_PRF(counter)        (TAD_PRF_OFFSET | (counter << 3))
#define TAD_PRF_CNTSEL_MASK     0xFF
#define TAD_MAX_COUNTERS        8

#define to_tad_pmu(p) (container_of(p, struct tad_pmu, pmu))

struct tad_region {
        void __iomem    *base;
};

struct tad_pmu {
        struct pmu pmu;
        struct tad_region *regions;
        u32 region_cnt;
        unsigned int cpu;
        struct hlist_node node;
        struct perf_event *events[TAD_MAX_COUNTERS];
        DECLARE_BITMAP(counters_map, TAD_MAX_COUNTERS);
};

enum mrvl_tad_pmu_version {
        TAD_PMU_V1 = 1,
        TAD_PMU_V2,
};

struct tad_pmu_data {
        int id;
};

static int tad_pmu_cpuhp_state;

static void tad_pmu_event_counter_read(struct perf_event *event)
{
        struct tad_pmu *tad_pmu = to_tad_pmu(event->pmu);
        struct hw_perf_event *hwc = &event->hw;
        u32 counter_idx = hwc->idx;
        u64 prev, new;
        int i;

        do {
                prev = local64_read(&hwc->prev_count);
                for (i = 0, new = 0; i < tad_pmu->region_cnt; i++)
                        new += readq(tad_pmu->regions[i].base +
                                     TAD_PFC(counter_idx));
        } while (local64_cmpxchg(&hwc->prev_count, prev, new) != prev);

        local64_add(new - prev, &event->count);
}

static void tad_pmu_event_counter_stop(struct perf_event *event, int flags)
{
        struct tad_pmu *tad_pmu = to_tad_pmu(event->pmu);
        struct hw_perf_event *hwc = &event->hw;
        u32 counter_idx = hwc->idx;
        int i;

        /* TAD()_PFC() stop counting on the write
         * which sets TAD()_PRF()[CNTSEL] == 0
         */
        for (i = 0; i < tad_pmu->region_cnt; i++) {
                writeq_relaxed(0, tad_pmu->regions[i].base +
                               TAD_PRF(counter_idx));
        }

        tad_pmu_event_counter_read(event);
        hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
}

static void tad_pmu_event_counter_start(struct perf_event *event, int flags)
{
        struct tad_pmu *tad_pmu = to_tad_pmu(event->pmu);
        struct hw_perf_event *hwc = &event->hw;
        u32 event_idx = event->attr.config;
        u32 counter_idx = hwc->idx;
        u64 reg_val;
        int i;

        hwc->state = 0;

        /* Typically TAD_PFC() are zeroed to start counting */
        for (i = 0; i < tad_pmu->region_cnt; i++)
                writeq_relaxed(0, tad_pmu->regions[i].base +
                               TAD_PFC(counter_idx));

        /* TAD()_PFC() start counting on the write
         * which sets TAD()_PRF()[CNTSEL] != 0
         */
        for (i = 0; i < tad_pmu->region_cnt; i++) {
                reg_val = event_idx & 0xFF;
                writeq_relaxed(reg_val, tad_pmu->regions[i].base +
                               TAD_PRF(counter_idx));
        }
}

static void tad_pmu_event_counter_del(struct perf_event *event, int flags)
{
        struct tad_pmu *tad_pmu = to_tad_pmu(event->pmu);
        struct hw_perf_event *hwc = &event->hw;
        int idx = hwc->idx;

        tad_pmu_event_counter_stop(event, flags | PERF_EF_UPDATE);
        tad_pmu->events[idx] = NULL;
        clear_bit(idx, tad_pmu->counters_map);
}

static int tad_pmu_event_counter_add(struct perf_event *event, int flags)
{
        struct tad_pmu *tad_pmu = to_tad_pmu(event->pmu);
        struct hw_perf_event *hwc = &event->hw;
        int idx;

        /* Get a free counter for this event */
        idx = find_first_zero_bit(tad_pmu->counters_map, TAD_MAX_COUNTERS);
        if (idx == TAD_MAX_COUNTERS)
                return -EAGAIN;

        set_bit(idx, tad_pmu->counters_map);

        hwc->idx = idx;
        hwc->state = PERF_HES_STOPPED;
        tad_pmu->events[idx] = event;

        if (flags & PERF_EF_START)
                tad_pmu_event_counter_start(event, flags);

        return 0;
}

static int tad_pmu_event_init(struct perf_event *event)
{
        struct tad_pmu *tad_pmu = to_tad_pmu(event->pmu);

        if (event->attr.type != event->pmu->type)
                return -ENOENT;

        if (!event->attr.disabled)
                return -EINVAL;

        if (event->state != PERF_EVENT_STATE_OFF)
                return -EINVAL;

        event->cpu = tad_pmu->cpu;
        event->hw.idx = -1;
        event->hw.config_base = event->attr.config;

        return 0;
}

static ssize_t tad_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 sysfs_emit(page, "event=0x%02llx\n", pmu_attr->id);
}

#define TAD_PMU_EVENT_ATTR(name, config)                        \
        PMU_EVENT_ATTR_ID(name, tad_pmu_event_show, config)

static struct attribute *tad_pmu_event_attrs[] = {
        TAD_PMU_EVENT_ATTR(tad_none, 0x0),
        TAD_PMU_EVENT_ATTR(tad_req_msh_in_any, 0x1),
        TAD_PMU_EVENT_ATTR(tad_req_msh_in_mn, 0x2),
        TAD_PMU_EVENT_ATTR(tad_req_msh_in_exlmn, 0x3),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_in_any, 0x4),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_in_mn, 0x5),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_in_exlmn, 0x6),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_in_dss, 0x7),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_in_retry_dss, 0x8),
        TAD_PMU_EVENT_ATTR(tad_dat_msh_in_any, 0x9),
        TAD_PMU_EVENT_ATTR(tad_dat_msh_in_dss, 0xa),
        TAD_PMU_EVENT_ATTR(tad_req_msh_out_any, 0xb),
        TAD_PMU_EVENT_ATTR(tad_req_msh_out_dss_rd, 0xc),
        TAD_PMU_EVENT_ATTR(tad_req_msh_out_dss_wr, 0xd),
        TAD_PMU_EVENT_ATTR(tad_req_msh_out_evict, 0xe),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_out_any, 0xf),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_out_retry_exlmn, 0x10),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_out_retry_mn, 0x11),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_out_exlmn, 0x12),
        TAD_PMU_EVENT_ATTR(tad_rsp_msh_out_mn, 0x13),
        TAD_PMU_EVENT_ATTR(tad_snp_msh_out_any, 0x14),
        TAD_PMU_EVENT_ATTR(tad_snp_msh_out_mn, 0x15),
        TAD_PMU_EVENT_ATTR(tad_snp_msh_out_exlmn, 0x16),
        TAD_PMU_EVENT_ATTR(tad_dat_msh_out_any, 0x17),
        TAD_PMU_EVENT_ATTR(tad_dat_msh_out_fill, 0x18),
        TAD_PMU_EVENT_ATTR(tad_dat_msh_out_dss, 0x19),
        TAD_PMU_EVENT_ATTR(tad_alloc_dtg, 0x1a),
        TAD_PMU_EVENT_ATTR(tad_alloc_ltg, 0x1b),
        TAD_PMU_EVENT_ATTR(tad_alloc_any, 0x1c),
        TAD_PMU_EVENT_ATTR(tad_hit_dtg, 0x1d),
        TAD_PMU_EVENT_ATTR(tad_hit_ltg, 0x1e),
        TAD_PMU_EVENT_ATTR(tad_hit_any, 0x1f),
        TAD_PMU_EVENT_ATTR(tad_tag_rd, 0x20),
        TAD_PMU_EVENT_ATTR(tad_dat_rd, 0x21),
        TAD_PMU_EVENT_ATTR(tad_dat_rd_byp, 0x22),
        TAD_PMU_EVENT_ATTR(tad_ifb_occ, 0x23),
        TAD_PMU_EVENT_ATTR(tad_req_occ, 0x24),
        NULL
};

static const struct attribute_group tad_pmu_events_attr_group = {
        .name = "events",
        .attrs = tad_pmu_event_attrs,
};

static struct attribute *ody_tad_pmu_event_attrs[] = {
        TAD_PMU_EVENT_ATTR(tad_req_msh_in_exlmn, 0x3),
        TAD_PMU_EVENT_ATTR(tad_alloc_dtg, 0x1a),
        TAD_PMU_EVENT_ATTR(tad_alloc_ltg, 0x1b),
        TAD_PMU_EVENT_ATTR(tad_alloc_any, 0x1c),
        TAD_PMU_EVENT_ATTR(tad_hit_dtg, 0x1d),
        TAD_PMU_EVENT_ATTR(tad_hit_ltg, 0x1e),
        TAD_PMU_EVENT_ATTR(tad_hit_any, 0x1f),
        TAD_PMU_EVENT_ATTR(tad_tag_rd, 0x20),
        TAD_PMU_EVENT_ATTR(tad_tot_cycle, 0xFF),
        NULL
};

static const struct attribute_group ody_tad_pmu_events_attr_group = {
        .name = "events",
        .attrs = ody_tad_pmu_event_attrs,
};

PMU_FORMAT_ATTR(event, "config:0-7");

static struct attribute *tad_pmu_format_attrs[] = {
        &format_attr_event.attr,
        NULL
};

static struct attribute_group tad_pmu_format_attr_group = {
        .name = "format",
        .attrs = tad_pmu_format_attrs,
};

static ssize_t tad_pmu_cpumask_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct tad_pmu *tad_pmu = to_tad_pmu(dev_get_drvdata(dev));

        return cpumap_print_to_pagebuf(true, buf, cpumask_of(tad_pmu->cpu));
}

static DEVICE_ATTR(cpumask, 0444, tad_pmu_cpumask_show, NULL);

static struct attribute *tad_pmu_cpumask_attrs[] = {
        &dev_attr_cpumask.attr,
        NULL
};

static struct attribute_group tad_pmu_cpumask_attr_group = {
        .attrs = tad_pmu_cpumask_attrs,
};

static const struct attribute_group *tad_pmu_attr_groups[] = {
        &tad_pmu_events_attr_group,
        &tad_pmu_format_attr_group,
        &tad_pmu_cpumask_attr_group,
        NULL
};

static const struct attribute_group *ody_tad_pmu_attr_groups[] = {
        &ody_tad_pmu_events_attr_group,
        &tad_pmu_format_attr_group,
        &tad_pmu_cpumask_attr_group,
        NULL
};

static int tad_pmu_probe(struct platform_device *pdev)
{
        const struct tad_pmu_data *dev_data;
        struct device *dev = &pdev->dev;
        struct tad_region *regions;
        struct tad_pmu *tad_pmu;
        struct resource *res;
        u32 tad_pmu_page_size;
        u32 tad_page_size;
        u32 tad_cnt;
        int version;
        int i, ret;
        char *name;

        tad_pmu = devm_kzalloc(&pdev->dev, sizeof(*tad_pmu), GFP_KERNEL);
        if (!tad_pmu)
                return -ENOMEM;

        platform_set_drvdata(pdev, tad_pmu);

        dev_data = device_get_match_data(&pdev->dev);
        if (!dev_data) {
                dev_err(&pdev->dev, "Error: No device match data found\n");
                return -ENODEV;
        }
        version = dev_data->id;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res) {
                dev_err(&pdev->dev, "Mem resource not found\n");
                return -ENODEV;
        }

        ret = device_property_read_u32(dev, "marvell,tad-page-size",
                                       &tad_page_size);
        if (ret) {
                dev_err(&pdev->dev, "Can't find tad-page-size property\n");
                return ret;
        }

        ret = device_property_read_u32(dev, "marvell,tad-pmu-page-size",
                                       &tad_pmu_page_size);
        if (ret) {
                dev_err(&pdev->dev, "Can't find tad-pmu-page-size property\n");
                return ret;
        }

        ret = device_property_read_u32(dev, "marvell,tad-cnt", &tad_cnt);
        if (ret) {
                dev_err(&pdev->dev, "Can't find tad-cnt property\n");
                return ret;
        }

        regions = devm_kcalloc(&pdev->dev, tad_cnt,
                               sizeof(*regions), GFP_KERNEL);
        if (!regions)
                return -ENOMEM;

        /* ioremap the distributed TAD pmu regions */
        for (i = 0; i < tad_cnt && res->start < res->end; i++) {
                regions[i].base = devm_ioremap(&pdev->dev,
                                               res->start,
                                               tad_pmu_page_size);
                if (!regions[i].base) {
                        dev_err(&pdev->dev, "TAD%d ioremap fail\n", i);
                        return -ENOMEM;
                }
                res->start += tad_page_size;
        }

        tad_pmu->regions = regions;
        tad_pmu->region_cnt = tad_cnt;

        tad_pmu->pmu = (struct pmu) {

                .module         = THIS_MODULE,
                .capabilities   = PERF_PMU_CAP_NO_EXCLUDE |
                                  PERF_PMU_CAP_NO_INTERRUPT,
                .task_ctx_nr    = perf_invalid_context,

                .event_init     = tad_pmu_event_init,
                .add            = tad_pmu_event_counter_add,
                .del            = tad_pmu_event_counter_del,
                .start          = tad_pmu_event_counter_start,
                .stop           = tad_pmu_event_counter_stop,
                .read           = tad_pmu_event_counter_read,
        };

        if (version == TAD_PMU_V1)
                tad_pmu->pmu.attr_groups = tad_pmu_attr_groups;
        else
                tad_pmu->pmu.attr_groups = ody_tad_pmu_attr_groups;

        tad_pmu->cpu = raw_smp_processor_id();

        /* Register pmu instance for cpu hotplug */
        ret = cpuhp_state_add_instance_nocalls(tad_pmu_cpuhp_state,
                                               &tad_pmu->node);
        if (ret) {
                dev_err(&pdev->dev, "Error %d registering hotplug\n", ret);
                return ret;
        }

        name = "tad";
        ret = perf_pmu_register(&tad_pmu->pmu, name, -1);
        if (ret)
                cpuhp_state_remove_instance_nocalls(tad_pmu_cpuhp_state,
                                                    &tad_pmu->node);

        return ret;
}

static void tad_pmu_remove(struct platform_device *pdev)
{
        struct tad_pmu *pmu = platform_get_drvdata(pdev);

        cpuhp_state_remove_instance_nocalls(tad_pmu_cpuhp_state,
                                                &pmu->node);
        perf_pmu_unregister(&pmu->pmu);
}

#if defined(CONFIG_OF) || defined(CONFIG_ACPI)
static const struct tad_pmu_data tad_pmu_data = {
        .id   = TAD_PMU_V1,
};
#endif

#ifdef CONFIG_ACPI
static const struct tad_pmu_data tad_pmu_v2_data = {
        .id   = TAD_PMU_V2,
};
#endif

#ifdef CONFIG_OF
static const struct of_device_id tad_pmu_of_match[] = {
        { .compatible = "marvell,cn10k-tad-pmu", .data = &tad_pmu_data },
        {},
};
#endif

#ifdef CONFIG_ACPI
static const struct acpi_device_id tad_pmu_acpi_match[] = {
        {"MRVL000B", (kernel_ulong_t)&tad_pmu_data},
        {"MRVL000D", (kernel_ulong_t)&tad_pmu_v2_data},
        {},
};
MODULE_DEVICE_TABLE(acpi, tad_pmu_acpi_match);
#endif

static struct platform_driver tad_pmu_driver = {
        .driver         = {
                .name   = "cn10k_tad_pmu",
                .of_match_table = of_match_ptr(tad_pmu_of_match),
                .acpi_match_table = ACPI_PTR(tad_pmu_acpi_match),
                .suppress_bind_attrs = true,
        },
        .probe          = tad_pmu_probe,
        .remove         = tad_pmu_remove,
};

static int tad_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
{
        struct tad_pmu *pmu = hlist_entry_safe(node, struct tad_pmu, node);
        unsigned 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;

        return 0;
}

static int __init tad_pmu_init(void)
{
        int ret;

        ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
                                      "perf/cn10k/tadpmu:online",
                                      NULL,
                                      tad_pmu_offline_cpu);
        if (ret < 0)
                return ret;
        tad_pmu_cpuhp_state = ret;
        ret = platform_driver_register(&tad_pmu_driver);
        if (ret)
                cpuhp_remove_multi_state(tad_pmu_cpuhp_state);

        return ret;
}

static void __exit tad_pmu_exit(void)
{
        platform_driver_unregister(&tad_pmu_driver);
        cpuhp_remove_multi_state(tad_pmu_cpuhp_state);
}

module_init(tad_pmu_init);
module_exit(tad_pmu_exit);

MODULE_DESCRIPTION("Marvell CN10K LLC-TAD Perf driver");
MODULE_AUTHOR("Bhaskara Budiredla <bbudiredla@marvell.com>");
MODULE_LICENSE("GPL v2");