/*
 * Support Intel RAPL energy consumption counters
 * Copyright (C) 2013 Google, Inc., Stephane Eranian
 *
 * Intel RAPL interface is specified in the IA-32 Manual Vol3b
 * section 14.7.1 (September 2013)
 *
 * RAPL provides more controls than just reporting energy consumption
 * however here we only expose the 3 energy consumption free running
 * counters (pp0, pkg, dram).
 *
 * Each of those counters increments in a power unit defined by the
 * RAPL_POWER_UNIT MSR. On SandyBridge, this unit is 1/(2^16) Joules
 * but it can vary.
 *
 * Counter to rapl events mappings:
 *
 *  pp0 counter: consumption of all physical cores (power plane 0)
 *        event: rapl_energy_cores
 *    perf code: 0x1
 *
 *  pkg counter: consumption of the whole processor package
 *        event: rapl_energy_pkg
 *    perf code: 0x2
 *
 * dram counter: consumption of the dram domain (servers only)
 *        event: rapl_energy_dram
 *    perf code: 0x3
 *
 * gpu counter: consumption of the builtin-gpu domain (client only)
 *        event: rapl_energy_gpu
 *    perf code: 0x4
 *
 *  psys counter: consumption of the builtin-psys domain (client only)
 *        event: rapl_energy_psys
 *    perf code: 0x5
 *
 * We manage those counters as free running (read-only). They may be
 * use simultaneously by other tools, such as turbostat.
 *
 * The events only support system-wide mode counting. There is no
 * sampling support because it does not make sense and is not
 * supported by the RAPL hardware.
 *
 * Because we want to avoid floating-point operations in the kernel,
 * the events are all reported in fixed point arithmetic (32.32).
 * Tools must adjust the counts to convert them to Watts using
 * the duration of the measurement. Tools may use a function such as
 * ldexp(raw_count, -32);
 */

#define pr_fmt(fmt) "RAPL PMU: " fmt

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/perf_event.h>
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
#include "../perf_event.h"

MODULE_LICENSE("GPL");

/*
 * RAPL energy status counters
 */
#define RAPL_IDX_PP0_NRG_STAT   0       /* all cores */
#define INTEL_RAPL_PP0          0x1     /* pseudo-encoding */
#define RAPL_IDX_PKG_NRG_STAT   1       /* entire package */
#define INTEL_RAPL_PKG          0x2     /* pseudo-encoding */
#define RAPL_IDX_RAM_NRG_STAT   2       /* DRAM */
#define INTEL_RAPL_RAM          0x3     /* pseudo-encoding */
#define RAPL_IDX_PP1_NRG_STAT   3       /* gpu */
#define INTEL_RAPL_PP1          0x4     /* pseudo-encoding */
#define RAPL_IDX_PSYS_NRG_STAT  4       /* psys */
#define INTEL_RAPL_PSYS         0x5     /* pseudo-encoding */

#define NR_RAPL_DOMAINS         0x5
static const char *const rapl_domain_names[NR_RAPL_DOMAINS] __initconst = {
        "pp0-core",
        "package",
        "dram",
        "pp1-gpu",
        "psys",
};

/* Clients have PP0, PKG */
#define RAPL_IDX_CLN    (1<<RAPL_IDX_PP0_NRG_STAT|\
                         1<<RAPL_IDX_PKG_NRG_STAT|\
                         1<<RAPL_IDX_PP1_NRG_STAT)

/* Servers have PP0, PKG, RAM */
#define RAPL_IDX_SRV    (1<<RAPL_IDX_PP0_NRG_STAT|\
                         1<<RAPL_IDX_PKG_NRG_STAT|\
                         1<<RAPL_IDX_RAM_NRG_STAT)

/* Servers have PP0, PKG, RAM, PP1 */
#define RAPL_IDX_HSW    (1<<RAPL_IDX_PP0_NRG_STAT|\
                         1<<RAPL_IDX_PKG_NRG_STAT|\
                         1<<RAPL_IDX_RAM_NRG_STAT|\
                         1<<RAPL_IDX_PP1_NRG_STAT)

/* SKL clients have PP0, PKG, RAM, PP1, PSYS */
#define RAPL_IDX_SKL_CLN (1<<RAPL_IDX_PP0_NRG_STAT|\
                          1<<RAPL_IDX_PKG_NRG_STAT|\
                          1<<RAPL_IDX_RAM_NRG_STAT|\
                          1<<RAPL_IDX_PP1_NRG_STAT|\
                          1<<RAPL_IDX_PSYS_NRG_STAT)

/* Knights Landing has PKG, RAM */
#define RAPL_IDX_KNL    (1<<RAPL_IDX_PKG_NRG_STAT|\
                         1<<RAPL_IDX_RAM_NRG_STAT)

/*
 * event code: LSB 8 bits, passed in attr->config
 * any other bit is reserved
 */
#define RAPL_EVENT_MASK 0xFFULL

#define DEFINE_RAPL_FORMAT_ATTR(_var, _name, _format)           \
static ssize_t __rapl_##_var##_show(struct kobject *kobj,       \
                                struct kobj_attribute *attr,    \
                                char *page)                     \
{                                                               \
        BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE);             \
        return sprintf(page, _format "\n");                     \
}                                                               \
static struct kobj_attribute format_attr_##_var =               \
        __ATTR(_name, 0444, __rapl_##_var##_show, NULL)

#define RAPL_CNTR_WIDTH 32

#define RAPL_EVENT_ATTR_STR(_name, v, str)                                      \
static struct perf_pmu_events_attr event_attr_##v = {                           \
        .attr           = __ATTR(_name, 0444, perf_event_sysfs_show, NULL),     \
        .id             = 0,                                                    \
        .event_str      = str,                                                  \
};

struct rapl_pmu {
        raw_spinlock_t          lock;
        int                     n_active;
        int                     cpu;
        struct list_head        active_list;
        struct pmu              *pmu;
        ktime_t                 timer_interval;
        struct hrtimer          hrtimer;
};

struct rapl_pmus {
        struct pmu              pmu;
        unsigned int            maxpkg;
        struct rapl_pmu         *pmus[];
};

 /* 1/2^hw_unit Joule */
static int rapl_hw_unit[NR_RAPL_DOMAINS] __read_mostly;
static struct rapl_pmus *rapl_pmus;
static cpumask_t rapl_cpu_mask;
static unsigned int rapl_cntr_mask;
static u64 rapl_timer_ms;

static inline struct rapl_pmu *cpu_to_rapl_pmu(unsigned int cpu)
{
        unsigned int pkgid = topology_logical_package_id(cpu);

        /*
         * The unsigned check also catches the '-1' return value for non
         * existent mappings in the topology map.
         */
        return pkgid < rapl_pmus->maxpkg ? rapl_pmus->pmus[pkgid] : NULL;
}

static inline u64 rapl_read_counter(struct perf_event *event)
{
        u64 raw;
        rdmsrl(event->hw.event_base, raw);
        return raw;
}

static inline u64 rapl_scale(u64 v, int cfg)
{
        if (cfg > NR_RAPL_DOMAINS) {
                pr_warn("Invalid domain %d, failed to scale data\n", cfg);
                return v;
        }
        /*
         * scale delta to smallest unit (1/2^32)
         * users must then scale back: count * 1/(1e9*2^32) to get Joules
         * or use ldexp(count, -32).
         * Watts = Joules/Time delta
         */
        return v << (32 - rapl_hw_unit[cfg - 1]);
}

static u64 rapl_event_update(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;
        u64 prev_raw_count, new_raw_count;
        s64 delta, sdelta;
        int shift = RAPL_CNTR_WIDTH;

again:
        prev_raw_count = local64_read(&hwc->prev_count);
        rdmsrl(event->hw.event_base, new_raw_count);

        if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
                            new_raw_count) != prev_raw_count) {
                cpu_relax();
                goto again;
        }

        /*
         * Now we have the new raw value and have updated the prev
         * timestamp already. We can now calculate the elapsed delta
         * (event-)time and add that to the generic event.
         *
         * Careful, not all hw sign-extends above the physical width
         * of the count.
         */
        delta = (new_raw_count << shift) - (prev_raw_count << shift);
        delta >>= shift;

        sdelta = rapl_scale(delta, event->hw.config);

        local64_add(sdelta, &event->count);

        return new_raw_count;
}

static void rapl_start_hrtimer(struct rapl_pmu *pmu)
{
       hrtimer_start(&pmu->hrtimer, pmu->timer_interval,
                     HRTIMER_MODE_REL_PINNED);
}

static enum hrtimer_restart rapl_hrtimer_handle(struct hrtimer *hrtimer)
{
        struct rapl_pmu *pmu = container_of(hrtimer, struct rapl_pmu, hrtimer);
        struct perf_event *event;
        unsigned long flags;

        if (!pmu->n_active)
                return HRTIMER_NORESTART;

        raw_spin_lock_irqsave(&pmu->lock, flags);

        list_for_each_entry(event, &pmu->active_list, active_entry)
                rapl_event_update(event);

        raw_spin_unlock_irqrestore(&pmu->lock, flags);

        hrtimer_forward_now(hrtimer, pmu->timer_interval);

        return HRTIMER_RESTART;
}

static void rapl_hrtimer_init(struct rapl_pmu *pmu)
{
        struct hrtimer *hr = &pmu->hrtimer;

        hrtimer_init(hr, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
        hr->function = rapl_hrtimer_handle;
}

static void __rapl_pmu_event_start(struct rapl_pmu *pmu,
                                   struct perf_event *event)
{
        if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
                return;

        event->hw.state = 0;

        list_add_tail(&event->active_entry, &pmu->active_list);

        local64_set(&event->hw.prev_count, rapl_read_counter(event));

        pmu->n_active++;
        if (pmu->n_active == 1)
                rapl_start_hrtimer(pmu);
}

static void rapl_pmu_event_start(struct perf_event *event, int mode)
{
        struct rapl_pmu *pmu = event->pmu_private;
        unsigned long flags;

        raw_spin_lock_irqsave(&pmu->lock, flags);
        __rapl_pmu_event_start(pmu, event);
        raw_spin_unlock_irqrestore(&pmu->lock, flags);
}

static void rapl_pmu_event_stop(struct perf_event *event, int mode)
{
        struct rapl_pmu *pmu = event->pmu_private;
        struct hw_perf_event *hwc = &event->hw;
        unsigned long flags;

        raw_spin_lock_irqsave(&pmu->lock, flags);

        /* mark event as deactivated and stopped */
        if (!(hwc->state & PERF_HES_STOPPED)) {
                WARN_ON_ONCE(pmu->n_active <= 0);
                pmu->n_active--;
                if (pmu->n_active == 0)
                        hrtimer_cancel(&pmu->hrtimer);

                list_del(&event->active_entry);

                WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
                hwc->state |= PERF_HES_STOPPED;
        }

        /* check if update of sw counter is necessary */
        if ((mode & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
                /*
                 * Drain the remaining delta count out of a event
                 * that we are disabling:
                 */
                rapl_event_update(event);
                hwc->state |= PERF_HES_UPTODATE;
        }

        raw_spin_unlock_irqrestore(&pmu->lock, flags);
}

static int rapl_pmu_event_add(struct perf_event *event, int mode)
{
        struct rapl_pmu *pmu = event->pmu_private;
        struct hw_perf_event *hwc = &event->hw;
        unsigned long flags;

        raw_spin_lock_irqsave(&pmu->lock, flags);

        hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;

        if (mode & PERF_EF_START)
                __rapl_pmu_event_start(pmu, event);

        raw_spin_unlock_irqrestore(&pmu->lock, flags);

        return 0;
}

static void rapl_pmu_event_del(struct perf_event *event, int flags)
{
        rapl_pmu_event_stop(event, PERF_EF_UPDATE);
}

static int rapl_pmu_event_init(struct perf_event *event)
{
        u64 cfg = event->attr.config & RAPL_EVENT_MASK;
        int bit, msr, ret = 0;
        struct rapl_pmu *pmu;

        /* only look at RAPL events */
        if (event->attr.type != rapl_pmus->pmu.type)
                return -ENOENT;

        /* check only supported bits are set */
        if (event->attr.config & ~RAPL_EVENT_MASK)
                return -EINVAL;

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

        event->event_caps |= PERF_EV_CAP_READ_ACTIVE_PKG;

        /*
         * check event is known (determines counter)
         */
        switch (cfg) {
        case INTEL_RAPL_PP0:
                bit = RAPL_IDX_PP0_NRG_STAT;
                msr = MSR_PP0_ENERGY_STATUS;
                break;
        case INTEL_RAPL_PKG:
                bit = RAPL_IDX_PKG_NRG_STAT;
                msr = MSR_PKG_ENERGY_STATUS;
                break;
        case INTEL_RAPL_RAM:
                bit = RAPL_IDX_RAM_NRG_STAT;
                msr = MSR_DRAM_ENERGY_STATUS;
                break;
        case INTEL_RAPL_PP1:
                bit = RAPL_IDX_PP1_NRG_STAT;
                msr = MSR_PP1_ENERGY_STATUS;
                break;
        case INTEL_RAPL_PSYS:
                bit = RAPL_IDX_PSYS_NRG_STAT;
                msr = MSR_PLATFORM_ENERGY_STATUS;
                break;
        default:
                return -EINVAL;
        }
        /* check event supported */
        if (!(rapl_cntr_mask & (1 << bit)))
                return -EINVAL;

        /* unsupported modes and filters */
        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  ||
            event->attr.sample_period) /* no sampling */
                return -EINVAL;

        /* must be done before validate_group */
        pmu = cpu_to_rapl_pmu(event->cpu);
        if (!pmu)
                return -EINVAL;
        event->cpu = pmu->cpu;
        event->pmu_private = pmu;
        event->hw.event_base = msr;
        event->hw.config = cfg;
        event->hw.idx = bit;

        return ret;
}

static void rapl_pmu_event_read(struct perf_event *event)
{
        rapl_event_update(event);
}

static ssize_t rapl_get_attr_cpumask(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        return cpumap_print_to_pagebuf(true, buf, &rapl_cpu_mask);
}

static DEVICE_ATTR(cpumask, S_IRUGO, rapl_get_attr_cpumask, NULL);

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

static struct attribute_group rapl_pmu_attr_group = {
        .attrs = rapl_pmu_attrs,
};

RAPL_EVENT_ATTR_STR(energy-cores, rapl_cores, "event=0x01");
RAPL_EVENT_ATTR_STR(energy-pkg  ,   rapl_pkg, "event=0x02");
RAPL_EVENT_ATTR_STR(energy-ram  ,   rapl_ram, "event=0x03");
RAPL_EVENT_ATTR_STR(energy-gpu  ,   rapl_gpu, "event=0x04");
RAPL_EVENT_ATTR_STR(energy-psys,   rapl_psys, "event=0x05");

RAPL_EVENT_ATTR_STR(energy-cores.unit, rapl_cores_unit, "Joules");
RAPL_EVENT_ATTR_STR(energy-pkg.unit  ,   rapl_pkg_unit, "Joules");
RAPL_EVENT_ATTR_STR(energy-ram.unit  ,   rapl_ram_unit, "Joules");
RAPL_EVENT_ATTR_STR(energy-gpu.unit  ,   rapl_gpu_unit, "Joules");
RAPL_EVENT_ATTR_STR(energy-psys.unit,   rapl_psys_unit, "Joules");

/*
 * we compute in 0.23 nJ increments regardless of MSR
 */
RAPL_EVENT_ATTR_STR(energy-cores.scale, rapl_cores_scale, "2.3283064365386962890625e-10");
RAPL_EVENT_ATTR_STR(energy-pkg.scale,     rapl_pkg_scale, "2.3283064365386962890625e-10");
RAPL_EVENT_ATTR_STR(energy-ram.scale,     rapl_ram_scale, "2.3283064365386962890625e-10");
RAPL_EVENT_ATTR_STR(energy-gpu.scale,     rapl_gpu_scale, "2.3283064365386962890625e-10");
RAPL_EVENT_ATTR_STR(energy-psys.scale,   rapl_psys_scale, "2.3283064365386962890625e-10");

static struct attribute *rapl_events_srv_attr[] = {
        EVENT_PTR(rapl_cores),
        EVENT_PTR(rapl_pkg),
        EVENT_PTR(rapl_ram),

        EVENT_PTR(rapl_cores_unit),
        EVENT_PTR(rapl_pkg_unit),
        EVENT_PTR(rapl_ram_unit),

        EVENT_PTR(rapl_cores_scale),
        EVENT_PTR(rapl_pkg_scale),
        EVENT_PTR(rapl_ram_scale),
        NULL,
};

static struct attribute *rapl_events_cln_attr[] = {
        EVENT_PTR(rapl_cores),
        EVENT_PTR(rapl_pkg),
        EVENT_PTR(rapl_gpu),

        EVENT_PTR(rapl_cores_unit),
        EVENT_PTR(rapl_pkg_unit),
        EVENT_PTR(rapl_gpu_unit),

        EVENT_PTR(rapl_cores_scale),
        EVENT_PTR(rapl_pkg_scale),
        EVENT_PTR(rapl_gpu_scale),
        NULL,
};

static struct attribute *rapl_events_hsw_attr[] = {
        EVENT_PTR(rapl_cores),
        EVENT_PTR(rapl_pkg),
        EVENT_PTR(rapl_gpu),
        EVENT_PTR(rapl_ram),

        EVENT_PTR(rapl_cores_unit),
        EVENT_PTR(rapl_pkg_unit),
        EVENT_PTR(rapl_gpu_unit),
        EVENT_PTR(rapl_ram_unit),

        EVENT_PTR(rapl_cores_scale),
        EVENT_PTR(rapl_pkg_scale),
        EVENT_PTR(rapl_gpu_scale),
        EVENT_PTR(rapl_ram_scale),
        NULL,
};

static struct attribute *rapl_events_skl_attr[] = {
        EVENT_PTR(rapl_cores),
        EVENT_PTR(rapl_pkg),
        EVENT_PTR(rapl_gpu),
        EVENT_PTR(rapl_ram),
        EVENT_PTR(rapl_psys),

        EVENT_PTR(rapl_cores_unit),
        EVENT_PTR(rapl_pkg_unit),
        EVENT_PTR(rapl_gpu_unit),
        EVENT_PTR(rapl_ram_unit),
        EVENT_PTR(rapl_psys_unit),

        EVENT_PTR(rapl_cores_scale),
        EVENT_PTR(rapl_pkg_scale),
        EVENT_PTR(rapl_gpu_scale),
        EVENT_PTR(rapl_ram_scale),
        EVENT_PTR(rapl_psys_scale),
        NULL,
};

static struct attribute *rapl_events_knl_attr[] = {
        EVENT_PTR(rapl_pkg),
        EVENT_PTR(rapl_ram),

        EVENT_PTR(rapl_pkg_unit),
        EVENT_PTR(rapl_ram_unit),

        EVENT_PTR(rapl_pkg_scale),
        EVENT_PTR(rapl_ram_scale),
        NULL,
};

static struct attribute_group rapl_pmu_events_group = {
        .name = "events",
        .attrs = NULL, /* patched at runtime */
};

DEFINE_RAPL_FORMAT_ATTR(event, event, "config:0-7");
static struct attribute *rapl_formats_attr[] = {
        &format_attr_event.attr,
        NULL,
};

static struct attribute_group rapl_pmu_format_group = {
        .name = "format",
        .attrs = rapl_formats_attr,
};

static const struct attribute_group *rapl_attr_groups[] = {
        &rapl_pmu_attr_group,
        &rapl_pmu_format_group,
        &rapl_pmu_events_group,
        NULL,
};

static int rapl_cpu_offline(unsigned int cpu)
{
        struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);
        int target;

        /* Check if exiting cpu is used for collecting rapl events */
        if (!cpumask_test_and_clear_cpu(cpu, &rapl_cpu_mask))
                return 0;

        pmu->cpu = -1;
        /* Find a new cpu to collect rapl events */
        target = cpumask_any_but(topology_core_cpumask(cpu), cpu);

        /* Migrate rapl events to the new target */
        if (target < nr_cpu_ids) {
                cpumask_set_cpu(target, &rapl_cpu_mask);
                pmu->cpu = target;
                perf_pmu_migrate_context(pmu->pmu, cpu, target);
        }
        return 0;
}

static int rapl_cpu_online(unsigned int cpu)
{
        struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);
        int target;

        if (!pmu) {
                pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu));
                if (!pmu)
                        return -ENOMEM;

                raw_spin_lock_init(&pmu->lock);
                INIT_LIST_HEAD(&pmu->active_list);
                pmu->pmu = &rapl_pmus->pmu;
                pmu->timer_interval = ms_to_ktime(rapl_timer_ms);
                rapl_hrtimer_init(pmu);

                rapl_pmus->pmus[topology_logical_package_id(cpu)] = pmu;
        }

        /*
         * Check if there is an online cpu in the package which collects rapl
         * events already.
         */
        target = cpumask_any_and(&rapl_cpu_mask, topology_core_cpumask(cpu));
        if (target < nr_cpu_ids)
                return 0;

        cpumask_set_cpu(cpu, &rapl_cpu_mask);
        pmu->cpu = cpu;
        return 0;
}

static int rapl_check_hw_unit(bool apply_quirk)
{
        u64 msr_rapl_power_unit_bits;
        int i;

        /* protect rdmsrl() to handle virtualization */
        if (rdmsrl_safe(MSR_RAPL_POWER_UNIT, &msr_rapl_power_unit_bits))
                return -1;
        for (i = 0; i < NR_RAPL_DOMAINS; i++)
                rapl_hw_unit[i] = (msr_rapl_power_unit_bits >> 8) & 0x1FULL;

        /*
         * DRAM domain on HSW server and KNL has fixed energy unit which can be
         * different than the unit from power unit MSR. See
         * "Intel Xeon Processor E5-1600 and E5-2600 v3 Product Families, V2
         * of 2. Datasheet, September 2014, Reference Number: 330784-001 "
         */
        if (apply_quirk)
                rapl_hw_unit[RAPL_IDX_RAM_NRG_STAT] = 16;

        /*
         * Calculate the timer rate:
         * Use reference of 200W for scaling the timeout to avoid counter
         * overflows. 200W = 200 Joules/sec
         * Divide interval by 2 to avoid lockstep (2 * 100)
         * if hw unit is 32, then we use 2 ms 1/200/2
         */
        rapl_timer_ms = 2;
        if (rapl_hw_unit[0] < 32) {
                rapl_timer_ms = (1000 / (2 * 100));
                rapl_timer_ms *= (1ULL << (32 - rapl_hw_unit[0] - 1));
        }
        return 0;
}

static void __init rapl_advertise(void)
{
        int i;

        pr_info("API unit is 2^-32 Joules, %d fixed counters, %llu ms ovfl timer\n",
                hweight32(rapl_cntr_mask), rapl_timer_ms);

        for (i = 0; i < NR_RAPL_DOMAINS; i++) {
                if (rapl_cntr_mask & (1 << i)) {
                        pr_info("hw unit of domain %s 2^-%d Joules\n",
                                rapl_domain_names[i], rapl_hw_unit[i]);
                }
        }
}

static void cleanup_rapl_pmus(void)
{
        int i;

        for (i = 0; i < rapl_pmus->maxpkg; i++)
                kfree(rapl_pmus->pmus[i]);
        kfree(rapl_pmus);
}

static int __init init_rapl_pmus(void)
{
        int maxpkg = topology_max_packages();
        size_t size;

        size = sizeof(*rapl_pmus) + maxpkg * sizeof(struct rapl_pmu *);
        rapl_pmus = kzalloc(size, GFP_KERNEL);
        if (!rapl_pmus)
                return -ENOMEM;

        rapl_pmus->maxpkg               = maxpkg;
        rapl_pmus->pmu.attr_groups      = rapl_attr_groups;
        rapl_pmus->pmu.task_ctx_nr      = perf_invalid_context;
        rapl_pmus->pmu.event_init       = rapl_pmu_event_init;
        rapl_pmus->pmu.add              = rapl_pmu_event_add;
        rapl_pmus->pmu.del              = rapl_pmu_event_del;
        rapl_pmus->pmu.start            = rapl_pmu_event_start;
        rapl_pmus->pmu.stop             = rapl_pmu_event_stop;
        rapl_pmus->pmu.read             = rapl_pmu_event_read;
        rapl_pmus->pmu.module           = THIS_MODULE;
        return 0;
}

#define X86_RAPL_MODEL_MATCH(model, init)       \
        { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&init }

struct intel_rapl_init_fun {
        bool apply_quirk;
        int cntr_mask;
        struct attribute **attrs;
};

static const struct intel_rapl_init_fun snb_rapl_init __initconst = {
        .apply_quirk = false,
        .cntr_mask = RAPL_IDX_CLN,
        .attrs = rapl_events_cln_attr,
};

static const struct intel_rapl_init_fun hsx_rapl_init __initconst = {
        .apply_quirk = true,
        .cntr_mask = RAPL_IDX_SRV,
        .attrs = rapl_events_srv_attr,
};

static const struct intel_rapl_init_fun hsw_rapl_init __initconst = {
        .apply_quirk = false,
        .cntr_mask = RAPL_IDX_HSW,
        .attrs = rapl_events_hsw_attr,
};

static const struct intel_rapl_init_fun snbep_rapl_init __initconst = {
        .apply_quirk = false,
        .cntr_mask = RAPL_IDX_SRV,
        .attrs = rapl_events_srv_attr,
};

static const struct intel_rapl_init_fun knl_rapl_init __initconst = {
        .apply_quirk = true,
        .cntr_mask = RAPL_IDX_KNL,
        .attrs = rapl_events_knl_attr,
};

static const struct intel_rapl_init_fun skl_rapl_init __initconst = {
        .apply_quirk = false,
        .cntr_mask = RAPL_IDX_SKL_CLN,
        .attrs = rapl_events_skl_attr,
};

static const struct x86_cpu_id rapl_cpu_match[] __initconst = {
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_SANDYBRIDGE,   snb_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_SANDYBRIDGE_X, snbep_rapl_init),

        X86_RAPL_MODEL_MATCH(INTEL_FAM6_IVYBRIDGE,   snb_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_IVYBRIDGE_X, snbep_rapl_init),

        X86_RAPL_MODEL_MATCH(INTEL_FAM6_HASWELL_CORE, hsw_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_HASWELL_X,    hsx_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_HASWELL_ULT,  hsw_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_HASWELL_GT3E, hsw_rapl_init),

        X86_RAPL_MODEL_MATCH(INTEL_FAM6_BROADWELL_CORE,   hsw_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_BROADWELL_GT3E,   hsw_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_BROADWELL_X,      hsx_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_BROADWELL_XEON_D, hsx_rapl_init),

        X86_RAPL_MODEL_MATCH(INTEL_FAM6_XEON_PHI_KNL, knl_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_XEON_PHI_KNM, knl_rapl_init),

        X86_RAPL_MODEL_MATCH(INTEL_FAM6_SKYLAKE_MOBILE,  skl_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_SKYLAKE_DESKTOP, skl_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_SKYLAKE_X,       hsx_rapl_init),

        X86_RAPL_MODEL_MATCH(INTEL_FAM6_KABYLAKE_MOBILE,  skl_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_KABYLAKE_DESKTOP, skl_rapl_init),

        X86_RAPL_MODEL_MATCH(INTEL_FAM6_CANNONLAKE_MOBILE,  skl_rapl_init),

        X86_RAPL_MODEL_MATCH(INTEL_FAM6_ATOM_GOLDMONT, hsw_rapl_init),
        X86_RAPL_MODEL_MATCH(INTEL_FAM6_ATOM_DENVERTON, hsw_rapl_init),

        X86_RAPL_MODEL_MATCH(INTEL_FAM6_ATOM_GEMINI_LAKE, hsw_rapl_init),
        {},
};

MODULE_DEVICE_TABLE(x86cpu, rapl_cpu_match);

static int __init rapl_pmu_init(void)
{
        const struct x86_cpu_id *id;
        struct intel_rapl_init_fun *rapl_init;
        bool apply_quirk;
        int ret;

        id = x86_match_cpu(rapl_cpu_match);
        if (!id)
                return -ENODEV;

        rapl_init = (struct intel_rapl_init_fun *)id->driver_data;
        apply_quirk = rapl_init->apply_quirk;
        rapl_cntr_mask = rapl_init->cntr_mask;
        rapl_pmu_events_group.attrs = rapl_init->attrs;

        ret = rapl_check_hw_unit(apply_quirk);
        if (ret)
                return ret;

        ret = init_rapl_pmus();
        if (ret)
                return ret;

        /*
         * Install callbacks. Core will call them for each online cpu.
         */
        ret = cpuhp_setup_state(CPUHP_AP_PERF_X86_RAPL_ONLINE,
                                "perf/x86/rapl:online",
                                rapl_cpu_online, rapl_cpu_offline);
        if (ret)
                goto out;

        ret = perf_pmu_register(&rapl_pmus->pmu, "power", -1);
        if (ret)
                goto out1;

        rapl_advertise();
        return 0;

out1:
        cpuhp_remove_state(CPUHP_AP_PERF_X86_RAPL_ONLINE);
out:
        pr_warn("Initialization failed (%d), disabled\n", ret);
        cleanup_rapl_pmus();
        return ret;
}
module_init(rapl_pmu_init);

static void __exit intel_rapl_exit(void)
{
        cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_RAPL_ONLINE);
        perf_pmu_unregister(&rapl_pmus->pmu);
        cleanup_rapl_pmus();
}
module_exit(intel_rapl_exit);