/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright © 2017-2018 Intel Corporation
 */

#ifndef __I915_PMU_H__
#define __I915_PMU_H__

#include <linux/hrtimer.h>
#include <linux/perf_event.h>
#include <linux/spinlock_types.h>
#include <uapi/drm/i915_drm.h>

struct drm_i915_private;
struct intel_gt;

/*
 * Non-engine events that we need to track enabled-disabled transition and
 * current state.
 */
enum i915_pmu_tracked_events {
        __I915_PMU_ACTUAL_FREQUENCY_ENABLED = 0,
        __I915_PMU_REQUESTED_FREQUENCY_ENABLED,
        __I915_PMU_RC6_RESIDENCY_ENABLED,
        __I915_PMU_TRACKED_EVENT_COUNT, /* count marker */
};

/*
 * Slots used from the sampling timer (non-engine events) with some extras for
 * convenience.
 */
enum {
        __I915_SAMPLE_FREQ_ACT = 0,
        __I915_SAMPLE_FREQ_REQ,
        __I915_SAMPLE_RC6,
        __I915_SAMPLE_RC6_LAST_REPORTED,
        __I915_NUM_PMU_SAMPLERS
};

#define I915_PMU_MAX_GT 2

/*
 * How many different events we track in the global PMU mask.
 *
 * It is also used to know to needed number of event reference counters.
 */
#define I915_PMU_MASK_BITS \
        (I915_ENGINE_SAMPLE_COUNT + \
         I915_PMU_MAX_GT * __I915_PMU_TRACKED_EVENT_COUNT)

#define I915_ENGINE_SAMPLE_COUNT (I915_SAMPLE_SEMA + 1)

struct i915_pmu_sample {
        u64 cur;
};

struct i915_pmu {
        /**
         * @base: PMU base.
         */
        struct pmu base;
        /**
         * @registered: PMU is registered and not in the unregistering process.
         */
        bool registered;
        /**
         * @name: Name as registered with perf core.
         */
        const char *name;
        /**
         * @lock: Lock protecting enable mask and ref count handling.
         */
        spinlock_t lock;
        /**
         * @unparked: GT unparked mask.
         */
        unsigned int unparked;
        /**
         * @timer: Timer for internal i915 PMU sampling.
         */
        struct hrtimer timer;
        /**
         * @enable: Bitmask of specific enabled events.
         *
         * For some events we need to track their state and do some internal
         * house keeping.
         *
         * Each engine event sampler type and event listed in enum
         * i915_pmu_tracked_events gets a bit in this field.
         *
         * Low bits are engine samplers and other events continue from there.
         */
        u32 enable;

        /**
         * @timer_last:
         *
         * Timestamp of the previous timer invocation.
         */
        ktime_t timer_last;

        /**
         * @enable_count: Reference counts for the enabled events.
         *
         * Array indices are mapped in the same way as bits in the @enable field
         * and they are used to control sampling on/off when multiple clients
         * are using the PMU API.
         */
        unsigned int enable_count[I915_PMU_MASK_BITS];
        /**
         * @timer_enabled: Should the internal sampling timer be running.
         */
        bool timer_enabled;
        /**
         * @sample: Current and previous (raw) counters for sampling events.
         *
         * These counters are updated from the i915 PMU sampling timer.
         *
         * Only global counters are held here, while the per-engine ones are in
         * struct intel_engine_cs.
         */
        struct i915_pmu_sample sample[I915_PMU_MAX_GT][__I915_NUM_PMU_SAMPLERS];
        /**
         * @sleep_last: Last time GT parked for RC6 estimation.
         */
        ktime_t sleep_last[I915_PMU_MAX_GT];
        /**
         * @irq_count: Number of interrupts
         *
         * Intentionally unsigned long to avoid atomics or heuristics on 32bit.
         * 4e9 interrupts are a lot and postprocessing can really deal with an
         * occasional wraparound easily. It's 32bit after all.
         */
        unsigned long irq_count;
        /**
         * @events_attr_group: Device events attribute group.
         */
        struct attribute_group events_attr_group;
        /**
         * @i915_attr: Memory block holding device attributes.
         */
        void *i915_attr;
        /**
         * @pmu_attr: Memory block holding device attributes.
         */
        void *pmu_attr;
};

#ifdef CONFIG_PERF_EVENTS
void i915_pmu_register(struct drm_i915_private *i915);
void i915_pmu_unregister(struct drm_i915_private *i915);
void i915_pmu_gt_parked(struct intel_gt *gt);
void i915_pmu_gt_unparked(struct intel_gt *gt);
#else
static inline void i915_pmu_register(struct drm_i915_private *i915) {}
static inline void i915_pmu_unregister(struct drm_i915_private *i915) {}
static inline void i915_pmu_gt_parked(struct intel_gt *gt) {}
static inline void i915_pmu_gt_unparked(struct intel_gt *gt) {}
#endif

#endif