// SPDX-License-Identifier: GPL-2.0
/*
 * CAVIUM THUNDERX2 SoC PMU UNCORE
 * Copyright (C) 2018 Cavium Inc.
 * Author: Ganapatrao Kulkarni <gkulkarni@cavium.com>
 */

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

/* Each ThunderX2(TX2) Socket has a L3C and DMC UNCORE PMU device.
 * Each UNCORE PMU device consists of 4 independent programmable counters.
 * Counters are 32 bit and do not support overflow interrupt,
 * they need to be sampled before overflow(i.e, at every 2 seconds).
 */

#define TX2_PMU_DMC_L3C_MAX_COUNTERS    4
#define TX2_PMU_CCPI2_MAX_COUNTERS      8
#define TX2_PMU_MAX_COUNTERS            TX2_PMU_CCPI2_MAX_COUNTERS


#define TX2_PMU_DMC_CHANNELS            8
#define TX2_PMU_L3_TILES                16

#define TX2_PMU_HRTIMER_INTERVAL        (2 * NSEC_PER_SEC)
#define GET_EVENTID(ev, mask)           ((ev->hw.config) & mask)
#define GET_COUNTERID(ev, mask)         ((ev->hw.idx) & mask)
 /* 1 byte per counter(4 counters).
  * Event id is encoded in bits [5:1] of a byte,
  */
#define DMC_EVENT_CFG(idx, val)         ((val) << (((idx) * 8) + 1))

/* bits[3:0] to select counters, are indexed from 8 to 15. */
#define CCPI2_COUNTER_OFFSET            8

#define L3C_COUNTER_CTL                 0xA8
#define L3C_COUNTER_DATA                0xAC
#define DMC_COUNTER_CTL                 0x234
#define DMC_COUNTER_DATA                0x240

#define CCPI2_PERF_CTL                  0x108
#define CCPI2_COUNTER_CTL               0x10C
#define CCPI2_COUNTER_SEL               0x12c
#define CCPI2_COUNTER_DATA_L            0x130
#define CCPI2_COUNTER_DATA_H            0x134

/* L3C event IDs */
#define L3_EVENT_READ_REQ               0xD
#define L3_EVENT_WRITEBACK_REQ          0xE
#define L3_EVENT_INV_N_WRITE_REQ        0xF
#define L3_EVENT_INV_REQ                0x10
#define L3_EVENT_EVICT_REQ              0x13
#define L3_EVENT_INV_N_WRITE_HIT        0x14
#define L3_EVENT_INV_HIT                0x15
#define L3_EVENT_READ_HIT               0x17
#define L3_EVENT_MAX                    0x18

/* DMC event IDs */
#define DMC_EVENT_COUNT_CYCLES          0x1
#define DMC_EVENT_WRITE_TXNS            0xB
#define DMC_EVENT_DATA_TRANSFERS        0xD
#define DMC_EVENT_READ_TXNS             0xF
#define DMC_EVENT_MAX                   0x10

#define CCPI2_EVENT_REQ_PKT_SENT        0x3D
#define CCPI2_EVENT_SNOOP_PKT_SENT      0x65
#define CCPI2_EVENT_DATA_PKT_SENT       0x105
#define CCPI2_EVENT_GIC_PKT_SENT        0x12D
#define CCPI2_EVENT_MAX                 0x200

#define CCPI2_PERF_CTL_ENABLE           BIT(0)
#define CCPI2_PERF_CTL_START            BIT(1)
#define CCPI2_PERF_CTL_RESET            BIT(4)
#define CCPI2_EVENT_LEVEL_RISING_EDGE   BIT(10)
#define CCPI2_EVENT_TYPE_EDGE_SENSITIVE BIT(11)

enum tx2_uncore_type {
        PMU_TYPE_L3C,
        PMU_TYPE_DMC,
        PMU_TYPE_CCPI2,
        PMU_TYPE_INVALID,
};

/*
 * Each socket has 3 uncore devices associated with a PMU. The DMC and
 * L3C have 4 32-bit counters and the CCPI2 has 8 64-bit counters.
 */
struct tx2_uncore_pmu {
        struct hlist_node hpnode;
        struct list_head  entry;
        struct pmu pmu;
        char *name;
        int node;
        int cpu;
        u32 max_counters;
        u32 counters_mask;
        u32 prorate_factor;
        u32 max_events;
        u32 events_mask;
        u64 hrtimer_interval;
        void __iomem *base;
        DECLARE_BITMAP(active_counters, TX2_PMU_MAX_COUNTERS);
        struct perf_event *events[TX2_PMU_MAX_COUNTERS];
        struct device *dev;
        struct hrtimer hrtimer;
        const struct attribute_group **attr_groups;
        enum tx2_uncore_type type;
        enum hrtimer_restart (*hrtimer_callback)(struct hrtimer *cb);
        void (*init_cntr_base)(struct perf_event *event,
                        struct tx2_uncore_pmu *tx2_pmu);
        void (*stop_event)(struct perf_event *event);
        void (*start_event)(struct perf_event *event, int flags);
};

static LIST_HEAD(tx2_pmus);

static inline struct tx2_uncore_pmu *pmu_to_tx2_pmu(struct pmu *pmu)
{
        return container_of(pmu, struct tx2_uncore_pmu, pmu);
}

#define TX2_PMU_FORMAT_ATTR(_var, _name, _format)                       \
static ssize_t                                                          \
__tx2_pmu_##_var##_show(struct device *dev,                             \
                               struct device_attribute *attr,           \
                               char *page)                              \
{                                                                       \
        BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE);                     \
        return sprintf(page, _format "\n");                             \
}                                                                       \
                                                                        \
static struct device_attribute format_attr_##_var =                     \
        __ATTR(_name, 0444, __tx2_pmu_##_var##_show, NULL)

TX2_PMU_FORMAT_ATTR(event, event, "config:0-4");
TX2_PMU_FORMAT_ATTR(event_ccpi2, event, "config:0-9");

static struct attribute *l3c_pmu_format_attrs[] = {
        &format_attr_event.attr,
        NULL,
};

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

static struct attribute *ccpi2_pmu_format_attrs[] = {
        &format_attr_event_ccpi2.attr,
        NULL,
};

static const struct attribute_group l3c_pmu_format_attr_group = {
        .name = "format",
        .attrs = l3c_pmu_format_attrs,
};

static const struct attribute_group dmc_pmu_format_attr_group = {
        .name = "format",
        .attrs = dmc_pmu_format_attrs,
};

static const struct attribute_group ccpi2_pmu_format_attr_group = {
        .name = "format",
        .attrs = ccpi2_pmu_format_attrs,
};

/*
 * sysfs event attributes
 */
static ssize_t tx2_pmu_event_show(struct device *dev,
                                    struct device_attribute *attr, char *buf)
{
        struct dev_ext_attribute *eattr;

        eattr = container_of(attr, struct dev_ext_attribute, attr);
        return sprintf(buf, "event=0x%lx\n", (unsigned long) eattr->var);
}

#define TX2_EVENT_ATTR(name, config) \
        PMU_EVENT_ATTR(name, tx2_pmu_event_attr_##name, \
                        config, tx2_pmu_event_show)

TX2_EVENT_ATTR(read_request, L3_EVENT_READ_REQ);
TX2_EVENT_ATTR(writeback_request, L3_EVENT_WRITEBACK_REQ);
TX2_EVENT_ATTR(inv_nwrite_request, L3_EVENT_INV_N_WRITE_REQ);
TX2_EVENT_ATTR(inv_request, L3_EVENT_INV_REQ);
TX2_EVENT_ATTR(evict_request, L3_EVENT_EVICT_REQ);
TX2_EVENT_ATTR(inv_nwrite_hit, L3_EVENT_INV_N_WRITE_HIT);
TX2_EVENT_ATTR(inv_hit, L3_EVENT_INV_HIT);
TX2_EVENT_ATTR(read_hit, L3_EVENT_READ_HIT);

static struct attribute *l3c_pmu_events_attrs[] = {
        &tx2_pmu_event_attr_read_request.attr.attr,
        &tx2_pmu_event_attr_writeback_request.attr.attr,
        &tx2_pmu_event_attr_inv_nwrite_request.attr.attr,
        &tx2_pmu_event_attr_inv_request.attr.attr,
        &tx2_pmu_event_attr_evict_request.attr.attr,
        &tx2_pmu_event_attr_inv_nwrite_hit.attr.attr,
        &tx2_pmu_event_attr_inv_hit.attr.attr,
        &tx2_pmu_event_attr_read_hit.attr.attr,
        NULL,
};

TX2_EVENT_ATTR(cnt_cycles, DMC_EVENT_COUNT_CYCLES);
TX2_EVENT_ATTR(write_txns, DMC_EVENT_WRITE_TXNS);
TX2_EVENT_ATTR(data_transfers, DMC_EVENT_DATA_TRANSFERS);
TX2_EVENT_ATTR(read_txns, DMC_EVENT_READ_TXNS);

static struct attribute *dmc_pmu_events_attrs[] = {
        &tx2_pmu_event_attr_cnt_cycles.attr.attr,
        &tx2_pmu_event_attr_write_txns.attr.attr,
        &tx2_pmu_event_attr_data_transfers.attr.attr,
        &tx2_pmu_event_attr_read_txns.attr.attr,
        NULL,
};

TX2_EVENT_ATTR(req_pktsent, CCPI2_EVENT_REQ_PKT_SENT);
TX2_EVENT_ATTR(snoop_pktsent, CCPI2_EVENT_SNOOP_PKT_SENT);
TX2_EVENT_ATTR(data_pktsent, CCPI2_EVENT_DATA_PKT_SENT);
TX2_EVENT_ATTR(gic_pktsent, CCPI2_EVENT_GIC_PKT_SENT);

static struct attribute *ccpi2_pmu_events_attrs[] = {
        &tx2_pmu_event_attr_req_pktsent.attr.attr,
        &tx2_pmu_event_attr_snoop_pktsent.attr.attr,
        &tx2_pmu_event_attr_data_pktsent.attr.attr,
        &tx2_pmu_event_attr_gic_pktsent.attr.attr,
        NULL,
};

static const struct attribute_group l3c_pmu_events_attr_group = {
        .name = "events",
        .attrs = l3c_pmu_events_attrs,
};

static const struct attribute_group dmc_pmu_events_attr_group = {
        .name = "events",
        .attrs = dmc_pmu_events_attrs,
};

static const struct attribute_group ccpi2_pmu_events_attr_group = {
        .name = "events",
        .attrs = ccpi2_pmu_events_attrs,
};

/*
 * sysfs cpumask attributes
 */
static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
                char *buf)
{
        struct tx2_uncore_pmu *tx2_pmu;

        tx2_pmu = pmu_to_tx2_pmu(dev_get_drvdata(dev));
        return cpumap_print_to_pagebuf(true, buf, cpumask_of(tx2_pmu->cpu));
}
static DEVICE_ATTR_RO(cpumask);

static struct attribute *tx2_pmu_cpumask_attrs[] = {
        &dev_attr_cpumask.attr,
        NULL,
};

static const struct attribute_group pmu_cpumask_attr_group = {
        .attrs = tx2_pmu_cpumask_attrs,
};

/*
 * Per PMU device attribute groups
 */
static const struct attribute_group *l3c_pmu_attr_groups[] = {
        &l3c_pmu_format_attr_group,
        &pmu_cpumask_attr_group,
        &l3c_pmu_events_attr_group,
        NULL
};

static const struct attribute_group *dmc_pmu_attr_groups[] = {
        &dmc_pmu_format_attr_group,
        &pmu_cpumask_attr_group,
        &dmc_pmu_events_attr_group,
        NULL
};

static const struct attribute_group *ccpi2_pmu_attr_groups[] = {
        &ccpi2_pmu_format_attr_group,
        &pmu_cpumask_attr_group,
        &ccpi2_pmu_events_attr_group,
        NULL
};

static inline u32 reg_readl(unsigned long addr)
{
        return readl((void __iomem *)addr);
}

static inline void reg_writel(u32 val, unsigned long addr)
{
        writel(val, (void __iomem *)addr);
}

static int alloc_counter(struct tx2_uncore_pmu *tx2_pmu)
{
        int counter;

        counter = find_first_zero_bit(tx2_pmu->active_counters,
                                tx2_pmu->max_counters);
        if (counter == tx2_pmu->max_counters)
                return -ENOSPC;

        set_bit(counter, tx2_pmu->active_counters);
        return counter;
}

static inline void free_counter(struct tx2_uncore_pmu *tx2_pmu, int counter)
{
        clear_bit(counter, tx2_pmu->active_counters);
}

static void init_cntr_base_l3c(struct perf_event *event,
                struct tx2_uncore_pmu *tx2_pmu)
{
        struct hw_perf_event *hwc = &event->hw;
        u32 cmask;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        cmask = tx2_pmu->counters_mask;

        /* counter ctrl/data reg offset at 8 */
        hwc->config_base = (unsigned long)tx2_pmu->base
                + L3C_COUNTER_CTL + (8 * GET_COUNTERID(event, cmask));
        hwc->event_base =  (unsigned long)tx2_pmu->base
                + L3C_COUNTER_DATA + (8 * GET_COUNTERID(event, cmask));
}

static void init_cntr_base_dmc(struct perf_event *event,
                struct tx2_uncore_pmu *tx2_pmu)
{
        struct hw_perf_event *hwc = &event->hw;
        u32 cmask;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        cmask = tx2_pmu->counters_mask;

        hwc->config_base = (unsigned long)tx2_pmu->base
                + DMC_COUNTER_CTL;
        /* counter data reg offset at 0xc */
        hwc->event_base = (unsigned long)tx2_pmu->base
                + DMC_COUNTER_DATA + (0xc * GET_COUNTERID(event, cmask));
}

static void init_cntr_base_ccpi2(struct perf_event *event,
                struct tx2_uncore_pmu *tx2_pmu)
{
        struct hw_perf_event *hwc = &event->hw;
        u32 cmask;

        cmask = tx2_pmu->counters_mask;

        hwc->config_base = (unsigned long)tx2_pmu->base
                + CCPI2_COUNTER_CTL + (4 * GET_COUNTERID(event, cmask));
        hwc->event_base =  (unsigned long)tx2_pmu->base;
}

static void uncore_start_event_l3c(struct perf_event *event, int flags)
{
        u32 val, emask;
        struct hw_perf_event *hwc = &event->hw;
        struct tx2_uncore_pmu *tx2_pmu;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        emask = tx2_pmu->events_mask;

        /* event id encoded in bits [07:03] */
        val = GET_EVENTID(event, emask) << 3;
        reg_writel(val, hwc->config_base);
        local64_set(&hwc->prev_count, 0);
        reg_writel(0, hwc->event_base);
}

static inline void uncore_stop_event_l3c(struct perf_event *event)
{
        reg_writel(0, event->hw.config_base);
}

static void uncore_start_event_dmc(struct perf_event *event, int flags)
{
        u32 val, cmask, emask;
        struct hw_perf_event *hwc = &event->hw;
        struct tx2_uncore_pmu *tx2_pmu;
        int idx, event_id;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        cmask = tx2_pmu->counters_mask;
        emask = tx2_pmu->events_mask;

        idx = GET_COUNTERID(event, cmask);
        event_id = GET_EVENTID(event, emask);

        /* enable and start counters.
         * 8 bits for each counter, bits[05:01] of a counter to set event type.
         */
        val = reg_readl(hwc->config_base);
        val &= ~DMC_EVENT_CFG(idx, 0x1f);
        val |= DMC_EVENT_CFG(idx, event_id);
        reg_writel(val, hwc->config_base);
        local64_set(&hwc->prev_count, 0);
        reg_writel(0, hwc->event_base);
}

static void uncore_stop_event_dmc(struct perf_event *event)
{
        u32 val, cmask;
        struct hw_perf_event *hwc = &event->hw;
        struct tx2_uncore_pmu *tx2_pmu;
        int idx;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        cmask = tx2_pmu->counters_mask;
        idx = GET_COUNTERID(event, cmask);

        /* clear event type(bits[05:01]) to stop counter */
        val = reg_readl(hwc->config_base);
        val &= ~DMC_EVENT_CFG(idx, 0x1f);
        reg_writel(val, hwc->config_base);
}

static void uncore_start_event_ccpi2(struct perf_event *event, int flags)
{
        u32 emask;
        struct hw_perf_event *hwc = &event->hw;
        struct tx2_uncore_pmu *tx2_pmu;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        emask = tx2_pmu->events_mask;

        /* Bit [09:00] to set event id.
         * Bits [10], set level to rising edge.
         * Bits [11], set type to edge sensitive.
         */
        reg_writel((CCPI2_EVENT_TYPE_EDGE_SENSITIVE |
                        CCPI2_EVENT_LEVEL_RISING_EDGE |
                        GET_EVENTID(event, emask)), hwc->config_base);

        /* reset[4], enable[0] and start[1] counters */
        reg_writel(CCPI2_PERF_CTL_RESET |
                        CCPI2_PERF_CTL_START |
                        CCPI2_PERF_CTL_ENABLE,
                        hwc->event_base + CCPI2_PERF_CTL);
        local64_set(&event->hw.prev_count, 0ULL);
}

static void uncore_stop_event_ccpi2(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;

        /* disable and stop counter */
        reg_writel(0, hwc->event_base + CCPI2_PERF_CTL);
}

static void tx2_uncore_event_update(struct perf_event *event)
{
        u64 prev, delta, new = 0;
        struct hw_perf_event *hwc = &event->hw;
        struct tx2_uncore_pmu *tx2_pmu;
        enum tx2_uncore_type type;
        u32 prorate_factor;
        u32 cmask, emask;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        type = tx2_pmu->type;
        cmask = tx2_pmu->counters_mask;
        emask = tx2_pmu->events_mask;
        prorate_factor = tx2_pmu->prorate_factor;
        if (type == PMU_TYPE_CCPI2) {
                reg_writel(CCPI2_COUNTER_OFFSET +
                                GET_COUNTERID(event, cmask),
                                hwc->event_base + CCPI2_COUNTER_SEL);
                new = reg_readl(hwc->event_base + CCPI2_COUNTER_DATA_H);
                new = (new << 32) +
                        reg_readl(hwc->event_base + CCPI2_COUNTER_DATA_L);
                prev = local64_xchg(&hwc->prev_count, new);
                delta = new - prev;
        } else {
                new = reg_readl(hwc->event_base);
                prev = local64_xchg(&hwc->prev_count, new);
                /* handles rollover of 32 bit counter */
                delta = (u32)(((1UL << 32) - prev) + new);
        }

        /* DMC event data_transfers granularity is 16 Bytes, convert it to 64 */
        if (type == PMU_TYPE_DMC &&
                        GET_EVENTID(event, emask) == DMC_EVENT_DATA_TRANSFERS)
                delta = delta/4;

        /* L3C and DMC has 16 and 8 interleave channels respectively.
         * The sampled value is for channel 0 and multiplied with
         * prorate_factor to get the count for a device.
         */
        local64_add(delta * prorate_factor, &event->count);
}

static enum tx2_uncore_type get_tx2_pmu_type(struct acpi_device *adev)
{
        int i = 0;
        struct acpi_tx2_pmu_device {
                __u8 id[ACPI_ID_LEN];
                enum tx2_uncore_type type;
        } devices[] = {
                {"CAV901D", PMU_TYPE_L3C},
                {"CAV901F", PMU_TYPE_DMC},
                {"CAV901E", PMU_TYPE_CCPI2},
                {"", PMU_TYPE_INVALID}
        };

        while (devices[i].type != PMU_TYPE_INVALID) {
                if (!strcmp(acpi_device_hid(adev), devices[i].id))
                        break;
                i++;
        }

        return devices[i].type;
}

static bool tx2_uncore_validate_event(struct pmu *pmu,
                                  struct perf_event *event, int *counters)
{
        if (is_software_event(event))
                return true;
        /* Reject groups spanning multiple HW PMUs. */
        if (event->pmu != pmu)
                return false;

        *counters = *counters + 1;
        return true;
}

/*
 * Make sure the group of events can be scheduled at once
 * on the PMU.
 */
static bool tx2_uncore_validate_event_group(struct perf_event *event,
                int max_counters)
{
        struct perf_event *sibling, *leader = event->group_leader;
        int counters = 0;

        if (event->group_leader == event)
                return true;

        if (!tx2_uncore_validate_event(event->pmu, leader, &counters))
                return false;

        for_each_sibling_event(sibling, leader) {
                if (!tx2_uncore_validate_event(event->pmu, sibling, &counters))
                        return false;
        }

        if (!tx2_uncore_validate_event(event->pmu, event, &counters))
                return false;

        /*
         * If the group requires more counters than the HW has,
         * it cannot ever be scheduled.
         */
        return counters <= max_counters;
}


static int tx2_uncore_event_init(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;
        struct tx2_uncore_pmu *tx2_pmu;

        /* Test the event attr type check for PMU enumeration */
        if (event->attr.type != event->pmu->type)
                return -ENOENT;

        /*
         * SOC PMU counters are shared across all cores.
         * Therefore, it does not support per-process mode.
         * Also, it does not support event sampling mode.
         */
        if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
                return -EINVAL;

        /* We have no filtering of any kind */
        if (event->attr.exclude_user    ||
            event->attr.exclude_kernel  ||
            event->attr.exclude_hv      ||
            event->attr.exclude_idle    ||
            event->attr.exclude_host    ||
            event->attr.exclude_guest)
                return -EINVAL;

        if (event->cpu < 0)
                return -EINVAL;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        if (tx2_pmu->cpu >= nr_cpu_ids)
                return -EINVAL;
        event->cpu = tx2_pmu->cpu;

        if (event->attr.config >= tx2_pmu->max_events)
                return -EINVAL;

        /* store event id */
        hwc->config = event->attr.config;

        /* Validate the group */
        if (!tx2_uncore_validate_event_group(event, tx2_pmu->max_counters))
                return -EINVAL;

        return 0;
}

static void tx2_uncore_event_start(struct perf_event *event, int flags)
{
        struct hw_perf_event *hwc = &event->hw;
        struct tx2_uncore_pmu *tx2_pmu;

        hwc->state = 0;
        tx2_pmu = pmu_to_tx2_pmu(event->pmu);

        tx2_pmu->start_event(event, flags);
        perf_event_update_userpage(event);

        /* No hrtimer needed for CCPI2, 64-bit counters */
        if (!tx2_pmu->hrtimer_callback)
                return;

        /* Start timer for first event */
        if (bitmap_weight(tx2_pmu->active_counters,
                                tx2_pmu->max_counters) == 1) {
                hrtimer_start(&tx2_pmu->hrtimer,
                        ns_to_ktime(tx2_pmu->hrtimer_interval),
                        HRTIMER_MODE_REL_PINNED);
        }
}

static void tx2_uncore_event_stop(struct perf_event *event, int flags)
{
        struct hw_perf_event *hwc = &event->hw;
        struct tx2_uncore_pmu *tx2_pmu;

        if (hwc->state & PERF_HES_UPTODATE)
                return;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        tx2_pmu->stop_event(event);
        WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
        hwc->state |= PERF_HES_STOPPED;
        if (flags & PERF_EF_UPDATE) {
                tx2_uncore_event_update(event);
                hwc->state |= PERF_HES_UPTODATE;
        }
}

static int tx2_uncore_event_add(struct perf_event *event, int flags)
{
        struct hw_perf_event *hwc = &event->hw;
        struct tx2_uncore_pmu *tx2_pmu;

        tx2_pmu = pmu_to_tx2_pmu(event->pmu);

        /* Allocate a free counter */
        hwc->idx  = alloc_counter(tx2_pmu);
        if (hwc->idx < 0)
                return -EAGAIN;

        tx2_pmu->events[hwc->idx] = event;
        /* set counter control and data registers base address */
        tx2_pmu->init_cntr_base(event, tx2_pmu);

        hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
        if (flags & PERF_EF_START)
                tx2_uncore_event_start(event, flags);

        return 0;
}

static void tx2_uncore_event_del(struct perf_event *event, int flags)
{
        struct tx2_uncore_pmu *tx2_pmu = pmu_to_tx2_pmu(event->pmu);
        struct hw_perf_event *hwc = &event->hw;
        u32 cmask;

        cmask = tx2_pmu->counters_mask;
        tx2_uncore_event_stop(event, PERF_EF_UPDATE);

        /* clear the assigned counter */
        free_counter(tx2_pmu, GET_COUNTERID(event, cmask));

        perf_event_update_userpage(event);
        tx2_pmu->events[hwc->idx] = NULL;
        hwc->idx = -1;

        if (!tx2_pmu->hrtimer_callback)
                return;

        if (bitmap_empty(tx2_pmu->active_counters, tx2_pmu->max_counters))
                hrtimer_cancel(&tx2_pmu->hrtimer);
}

static void tx2_uncore_event_read(struct perf_event *event)
{
        tx2_uncore_event_update(event);
}

static enum hrtimer_restart tx2_hrtimer_callback(struct hrtimer *timer)
{
        struct tx2_uncore_pmu *tx2_pmu;
        int max_counters, idx;

        tx2_pmu = container_of(timer, struct tx2_uncore_pmu, hrtimer);
        max_counters = tx2_pmu->max_counters;

        if (bitmap_empty(tx2_pmu->active_counters, max_counters))
                return HRTIMER_NORESTART;

        for_each_set_bit(idx, tx2_pmu->active_counters, max_counters) {
                struct perf_event *event = tx2_pmu->events[idx];

                tx2_uncore_event_update(event);
        }
        hrtimer_forward_now(timer, ns_to_ktime(tx2_pmu->hrtimer_interval));
        return HRTIMER_RESTART;
}

static int tx2_uncore_pmu_register(
                struct tx2_uncore_pmu *tx2_pmu)
{
        struct device *dev = tx2_pmu->dev;
        char *name = tx2_pmu->name;

        /* Perf event registration */
        tx2_pmu->pmu = (struct pmu) {
                .module         = THIS_MODULE,
                .attr_groups    = tx2_pmu->attr_groups,
                .task_ctx_nr    = perf_invalid_context,
                .event_init     = tx2_uncore_event_init,
                .add            = tx2_uncore_event_add,
                .del            = tx2_uncore_event_del,
                .start          = tx2_uncore_event_start,
                .stop           = tx2_uncore_event_stop,
                .read           = tx2_uncore_event_read,
        };

        tx2_pmu->pmu.name = devm_kasprintf(dev, GFP_KERNEL,
                        "%s", name);

        return perf_pmu_register(&tx2_pmu->pmu, tx2_pmu->pmu.name, -1);
}

static int tx2_uncore_pmu_add_dev(struct tx2_uncore_pmu *tx2_pmu)
{
        int ret, cpu;

        cpu = cpumask_any_and(cpumask_of_node(tx2_pmu->node),
                        cpu_online_mask);

        tx2_pmu->cpu = cpu;

        if (tx2_pmu->hrtimer_callback) {
                hrtimer_init(&tx2_pmu->hrtimer,
                                CLOCK_MONOTONIC, HRTIMER_MODE_REL);
                tx2_pmu->hrtimer.function = tx2_pmu->hrtimer_callback;
        }

        ret = tx2_uncore_pmu_register(tx2_pmu);
        if (ret) {
                dev_err(tx2_pmu->dev, "%s PMU: Failed to init driver\n",
                                tx2_pmu->name);
                return -ENODEV;
        }

        /* register hotplug callback for the pmu */
        ret = cpuhp_state_add_instance(
                        CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
                        &tx2_pmu->hpnode);
        if (ret) {
                dev_err(tx2_pmu->dev, "Error %d registering hotplug", ret);
                return ret;
        }

        /* Add to list */
        list_add(&tx2_pmu->entry, &tx2_pmus);

        dev_dbg(tx2_pmu->dev, "%s PMU UNCORE registered\n",
                        tx2_pmu->pmu.name);
        return ret;
}

static struct tx2_uncore_pmu *tx2_uncore_pmu_init_dev(struct device *dev,
                acpi_handle handle, struct acpi_device *adev, u32 type)
{
        struct tx2_uncore_pmu *tx2_pmu;
        void __iomem *base;
        struct resource res;
        struct resource_entry *rentry;
        struct list_head list;
        int ret;

        INIT_LIST_HEAD(&list);
        ret = acpi_dev_get_resources(adev, &list, NULL, NULL);
        if (ret <= 0) {
                dev_err(dev, "failed to parse _CRS method, error %d\n", ret);
                return NULL;
        }

        list_for_each_entry(rentry, &list, node) {
                if (resource_type(rentry->res) == IORESOURCE_MEM) {
                        res = *rentry->res;
                        break;
                }
        }

        if (!rentry->res)
                return NULL;

        acpi_dev_free_resource_list(&list);
        base = devm_ioremap_resource(dev, &res);
        if (IS_ERR(base)) {
                dev_err(dev, "PMU type %d: Fail to map resource\n", type);
                return NULL;
        }

        tx2_pmu = devm_kzalloc(dev, sizeof(*tx2_pmu), GFP_KERNEL);
        if (!tx2_pmu)
                return NULL;

        tx2_pmu->dev = dev;
        tx2_pmu->type = type;
        tx2_pmu->base = base;
        tx2_pmu->node = dev_to_node(dev);
        INIT_LIST_HEAD(&tx2_pmu->entry);

        switch (tx2_pmu->type) {
        case PMU_TYPE_L3C:
                tx2_pmu->max_counters = TX2_PMU_DMC_L3C_MAX_COUNTERS;
                tx2_pmu->counters_mask = 0x3;
                tx2_pmu->prorate_factor = TX2_PMU_L3_TILES;
                tx2_pmu->max_events = L3_EVENT_MAX;
                tx2_pmu->events_mask = 0x1f;
                tx2_pmu->hrtimer_interval = TX2_PMU_HRTIMER_INTERVAL;
                tx2_pmu->hrtimer_callback = tx2_hrtimer_callback;
                tx2_pmu->attr_groups = l3c_pmu_attr_groups;
                tx2_pmu->name = devm_kasprintf(dev, GFP_KERNEL,
                                "uncore_l3c_%d", tx2_pmu->node);
                tx2_pmu->init_cntr_base = init_cntr_base_l3c;
                tx2_pmu->start_event = uncore_start_event_l3c;
                tx2_pmu->stop_event = uncore_stop_event_l3c;
                break;
        case PMU_TYPE_DMC:
                tx2_pmu->max_counters = TX2_PMU_DMC_L3C_MAX_COUNTERS;
                tx2_pmu->counters_mask = 0x3;
                tx2_pmu->prorate_factor = TX2_PMU_DMC_CHANNELS;
                tx2_pmu->max_events = DMC_EVENT_MAX;
                tx2_pmu->events_mask = 0x1f;
                tx2_pmu->hrtimer_interval = TX2_PMU_HRTIMER_INTERVAL;
                tx2_pmu->hrtimer_callback = tx2_hrtimer_callback;
                tx2_pmu->attr_groups = dmc_pmu_attr_groups;
                tx2_pmu->name = devm_kasprintf(dev, GFP_KERNEL,
                                "uncore_dmc_%d", tx2_pmu->node);
                tx2_pmu->init_cntr_base = init_cntr_base_dmc;
                tx2_pmu->start_event = uncore_start_event_dmc;
                tx2_pmu->stop_event = uncore_stop_event_dmc;
                break;
        case PMU_TYPE_CCPI2:
                /* CCPI2 has 8 counters */
                tx2_pmu->max_counters = TX2_PMU_CCPI2_MAX_COUNTERS;
                tx2_pmu->counters_mask = 0x7;
                tx2_pmu->prorate_factor = 1;
                tx2_pmu->max_events = CCPI2_EVENT_MAX;
                tx2_pmu->events_mask = 0x1ff;
                tx2_pmu->attr_groups = ccpi2_pmu_attr_groups;
                tx2_pmu->name = devm_kasprintf(dev, GFP_KERNEL,
                                "uncore_ccpi2_%d", tx2_pmu->node);
                tx2_pmu->init_cntr_base = init_cntr_base_ccpi2;
                tx2_pmu->start_event = uncore_start_event_ccpi2;
                tx2_pmu->stop_event = uncore_stop_event_ccpi2;
                tx2_pmu->hrtimer_callback = NULL;
                break;
        case PMU_TYPE_INVALID:
                devm_kfree(dev, tx2_pmu);
                return NULL;
        }

        return tx2_pmu;
}

static acpi_status tx2_uncore_pmu_add(acpi_handle handle, u32 level,
                                    void *data, void **return_value)
{
        struct tx2_uncore_pmu *tx2_pmu;
        struct acpi_device *adev;
        enum tx2_uncore_type type;

        if (acpi_bus_get_device(handle, &adev))
                return AE_OK;
        if (acpi_bus_get_status(adev) || !adev->status.present)
                return AE_OK;

        type = get_tx2_pmu_type(adev);
        if (type == PMU_TYPE_INVALID)
                return AE_OK;

        tx2_pmu = tx2_uncore_pmu_init_dev((struct device *)data,
                        handle, adev, type);

        if (!tx2_pmu)
                return AE_ERROR;

        if (tx2_uncore_pmu_add_dev(tx2_pmu)) {
                /* Can't add the PMU device, abort */
                return AE_ERROR;
        }
        return AE_OK;
}

static int tx2_uncore_pmu_online_cpu(unsigned int cpu,
                struct hlist_node *hpnode)
{
        struct tx2_uncore_pmu *tx2_pmu;

        tx2_pmu = hlist_entry_safe(hpnode,
                        struct tx2_uncore_pmu, hpnode);

        /* Pick this CPU, If there is no CPU/PMU association and both are
         * from same node.
         */
        if ((tx2_pmu->cpu >= nr_cpu_ids) &&
                (tx2_pmu->node == cpu_to_node(cpu)))
                tx2_pmu->cpu = cpu;

        return 0;
}

static int tx2_uncore_pmu_offline_cpu(unsigned int cpu,
                struct hlist_node *hpnode)
{
        int new_cpu;
        struct tx2_uncore_pmu *tx2_pmu;
        struct cpumask cpu_online_mask_temp;

        tx2_pmu = hlist_entry_safe(hpnode,
                        struct tx2_uncore_pmu, hpnode);

        if (cpu != tx2_pmu->cpu)
                return 0;

        if (tx2_pmu->hrtimer_callback)
                hrtimer_cancel(&tx2_pmu->hrtimer);

        cpumask_copy(&cpu_online_mask_temp, cpu_online_mask);
        cpumask_clear_cpu(cpu, &cpu_online_mask_temp);
        new_cpu = cpumask_any_and(
                        cpumask_of_node(tx2_pmu->node),
                        &cpu_online_mask_temp);

        tx2_pmu->cpu = new_cpu;
        if (new_cpu >= nr_cpu_ids)
                return 0;
        perf_pmu_migrate_context(&tx2_pmu->pmu, cpu, new_cpu);

        return 0;
}

static const struct acpi_device_id tx2_uncore_acpi_match[] = {
        {"CAV901C", 0},
        {},
};
MODULE_DEVICE_TABLE(acpi, tx2_uncore_acpi_match);

static int tx2_uncore_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        acpi_handle handle;
        acpi_status status;

        set_dev_node(dev, acpi_get_node(ACPI_HANDLE(dev)));

        if (!has_acpi_companion(dev))
                return -ENODEV;

        handle = ACPI_HANDLE(dev);
        if (!handle)
                return -EINVAL;

        /* Walk through the tree for all PMU UNCORE devices */
        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
                                     tx2_uncore_pmu_add,
                                     NULL, dev, NULL);
        if (ACPI_FAILURE(status)) {
                dev_err(dev, "failed to probe PMU devices\n");
                return_ACPI_STATUS(status);
        }

        dev_info(dev, "node%d: pmu uncore registered\n", dev_to_node(dev));
        return 0;
}

static int tx2_uncore_remove(struct platform_device *pdev)
{
        struct tx2_uncore_pmu *tx2_pmu, *temp;
        struct device *dev = &pdev->dev;

        if (!list_empty(&tx2_pmus)) {
                list_for_each_entry_safe(tx2_pmu, temp, &tx2_pmus, entry) {
                        if (tx2_pmu->node == dev_to_node(dev)) {
                                cpuhp_state_remove_instance_nocalls(
                                        CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
                                        &tx2_pmu->hpnode);
                                perf_pmu_unregister(&tx2_pmu->pmu);
                                list_del(&tx2_pmu->entry);
                        }
                }
        }
        return 0;
}

static struct platform_driver tx2_uncore_driver = {
        .driver = {
                .name           = "tx2-uncore-pmu",
                .acpi_match_table = ACPI_PTR(tx2_uncore_acpi_match),
        },
        .probe = tx2_uncore_probe,
        .remove = tx2_uncore_remove,
};

static int __init tx2_uncore_driver_init(void)
{
        int ret;

        ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
                                      "perf/tx2/uncore:online",
                                      tx2_uncore_pmu_online_cpu,
                                      tx2_uncore_pmu_offline_cpu);
        if (ret) {
                pr_err("TX2 PMU: setup hotplug failed(%d)\n", ret);
                return ret;
        }
        ret = platform_driver_register(&tx2_uncore_driver);
        if (ret)
                cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE);

        return ret;
}
module_init(tx2_uncore_driver_init);

static void __exit tx2_uncore_driver_exit(void)
{
        platform_driver_unregister(&tx2_uncore_driver);
        cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE);
}
module_exit(tx2_uncore_driver_exit);

MODULE_DESCRIPTION("ThunderX2 UNCORE PMU driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Ganapatrao Kulkarni <gkulkarni@cavium.com>");