/*
 * perf_event_intel_rapl.c: 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)
{
	return rapl_pmus->pmus[topology_logical_package_id(cpu)];
}

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);
	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,
};

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;

	/*
	 * 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_cpu_prepare(unsigned int cpu)
{
	struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);

	if (pmu)
		return 0;

	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);
	pmu->cpu = -1;
	rapl_hrtimer_init(pmu);
	rapl_pmus->pmus[topology_logical_package_id(cpu)] = pmu;
	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;
	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,    hsw_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,	  hsw_rapl_init),
	X86_RAPL_MODEL_MATCH(INTEL_FAM6_BROADWELL_XEON_D, hsw_rapl_init),

	X86_RAPL_MODEL_MATCH(INTEL_FAM6_XEON_PHI_KNL, 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_ATOM_GOLDMONT, 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_PERF_X86_RAPL_PREP, "PERF_X86_RAPL_PREP",
				rapl_cpu_prepare, NULL);
	if (ret)
		goto out;

	ret = cpuhp_setup_state(CPUHP_AP_PERF_X86_RAPL_ONLINE,
				"AP_PERF_X86_RAPL_ONLINE",
				rapl_cpu_online, rapl_cpu_offline);
	if (ret)
		goto out1;

	ret = perf_pmu_register(&rapl_pmus->pmu, "power", -1);
	if (ret)
		goto out2;

	rapl_advertise();
	return 0;

out2:
	cpuhp_remove_state(CPUHP_AP_PERF_X86_RAPL_ONLINE);
out1:
	cpuhp_remove_state(CPUHP_PERF_X86_RAPL_PREP);
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);
	cpuhp_remove_state_nocalls(CPUHP_PERF_X86_RAPL_PREP);
	perf_pmu_unregister(&rapl_pmus->pmu);
	cleanup_rapl_pmus();
}
module_exit(intel_rapl_exit);