// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2018 Broadcom
 */

/**
 * DOC: VC4 V3D performance monitor module
 *
 * The V3D block provides 16 hardware counters which can count various events.
 */

#include <drm/drm_print.h>

#include "vc4_drv.h"
#include "vc4_regs.h"

#define VC4_PERFMONID_MIN       1
#define VC4_PERFMONID_MAX       U32_MAX

void vc4_perfmon_get(struct vc4_perfmon *perfmon)
{
        struct vc4_dev *vc4;

        if (!perfmon)
                return;

        vc4 = perfmon->dev;
        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return;

        refcount_inc(&perfmon->refcnt);
}

void vc4_perfmon_put(struct vc4_perfmon *perfmon)
{
        struct vc4_dev *vc4;

        if (!perfmon)
                return;

        vc4 = perfmon->dev;
        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return;

        if (refcount_dec_and_test(&perfmon->refcnt))
                kfree(perfmon);
}

void vc4_perfmon_start(struct vc4_dev *vc4, struct vc4_perfmon *perfmon)
{
        unsigned int i;
        u32 mask;

        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return;

        if (WARN_ON_ONCE(!perfmon || vc4->active_perfmon))
                return;

        for (i = 0; i < perfmon->ncounters; i++)
                V3D_WRITE(V3D_PCTRS(i), perfmon->events[i]);

        mask = GENMASK(perfmon->ncounters - 1, 0);
        V3D_WRITE(V3D_PCTRC, mask);
        V3D_WRITE(V3D_PCTRE, V3D_PCTRE_EN | mask);
        vc4->active_perfmon = perfmon;
}

void vc4_perfmon_stop(struct vc4_dev *vc4, struct vc4_perfmon *perfmon,
                      bool capture)
{
        unsigned int i;

        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return;

        if (WARN_ON_ONCE(!vc4->active_perfmon ||
                         perfmon != vc4->active_perfmon))
                return;

        if (capture) {
                for (i = 0; i < perfmon->ncounters; i++)
                        perfmon->counters[i] += V3D_READ(V3D_PCTR(i));
        }

        V3D_WRITE(V3D_PCTRE, 0);
        vc4->active_perfmon = NULL;
}

struct vc4_perfmon *vc4_perfmon_find(struct vc4_file *vc4file, int id)
{
        struct vc4_dev *vc4 = vc4file->dev;
        struct vc4_perfmon *perfmon;

        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return NULL;

        mutex_lock(&vc4file->perfmon.lock);
        perfmon = idr_find(&vc4file->perfmon.idr, id);
        vc4_perfmon_get(perfmon);
        mutex_unlock(&vc4file->perfmon.lock);

        return perfmon;
}

void vc4_perfmon_open_file(struct vc4_file *vc4file)
{
        struct vc4_dev *vc4 = vc4file->dev;

        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return;

        mutex_init(&vc4file->perfmon.lock);
        idr_init_base(&vc4file->perfmon.idr, VC4_PERFMONID_MIN);
        vc4file->dev = vc4;
}

static int vc4_perfmon_idr_del(int id, void *elem, void *data)
{
        struct vc4_perfmon *perfmon = elem;
        struct vc4_dev *vc4 = (struct vc4_dev *)data;

        /* If the active perfmon is being destroyed, stop it first */
        if (perfmon == vc4->active_perfmon)
                vc4_perfmon_stop(vc4, perfmon, false);

        vc4_perfmon_put(perfmon);

        return 0;
}

void vc4_perfmon_close_file(struct vc4_file *vc4file)
{
        struct vc4_dev *vc4 = vc4file->dev;

        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return;

        mutex_lock(&vc4file->perfmon.lock);
        idr_for_each(&vc4file->perfmon.idr, vc4_perfmon_idr_del, vc4);
        idr_destroy(&vc4file->perfmon.idr);
        mutex_unlock(&vc4file->perfmon.lock);
        mutex_destroy(&vc4file->perfmon.lock);
}

int vc4_perfmon_create_ioctl(struct drm_device *dev, void *data,
                             struct drm_file *file_priv)
{
        struct vc4_dev *vc4 = to_vc4_dev(dev);
        struct vc4_file *vc4file = file_priv->driver_priv;
        struct drm_vc4_perfmon_create *req = data;
        struct vc4_perfmon *perfmon;
        unsigned int i;
        int ret;

        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return -ENODEV;

        if (!vc4->v3d) {
                DRM_DEBUG("Creating perfmon no VC4 V3D probed\n");
                return -ENODEV;
        }

        /* Number of monitored counters cannot exceed HW limits. */
        if (req->ncounters > DRM_VC4_MAX_PERF_COUNTERS ||
            !req->ncounters)
                return -EINVAL;

        /* Make sure all events are valid. */
        for (i = 0; i < req->ncounters; i++) {
                if (req->events[i] >= VC4_PERFCNT_NUM_EVENTS)
                        return -EINVAL;
        }

        perfmon = kzalloc_flex(*perfmon, counters, req->ncounters);
        if (!perfmon)
                return -ENOMEM;
        perfmon->dev = vc4;

        for (i = 0; i < req->ncounters; i++)
                perfmon->events[i] = req->events[i];

        perfmon->ncounters = req->ncounters;

        refcount_set(&perfmon->refcnt, 1);

        mutex_lock(&vc4file->perfmon.lock);
        ret = idr_alloc(&vc4file->perfmon.idr, perfmon, VC4_PERFMONID_MIN,
                        VC4_PERFMONID_MAX, GFP_KERNEL);
        mutex_unlock(&vc4file->perfmon.lock);

        if (ret < 0) {
                kfree(perfmon);
                return ret;
        }

        req->id = ret;
        return 0;
}

int vc4_perfmon_destroy_ioctl(struct drm_device *dev, void *data,
                              struct drm_file *file_priv)
{
        struct vc4_dev *vc4 = to_vc4_dev(dev);
        struct vc4_file *vc4file = file_priv->driver_priv;
        struct drm_vc4_perfmon_destroy *req = data;
        struct vc4_perfmon *perfmon;

        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return -ENODEV;

        if (!vc4->v3d) {
                DRM_DEBUG("Destroying perfmon no VC4 V3D probed\n");
                return -ENODEV;
        }

        mutex_lock(&vc4file->perfmon.lock);
        perfmon = idr_remove(&vc4file->perfmon.idr, req->id);
        mutex_unlock(&vc4file->perfmon.lock);

        if (!perfmon)
                return -EINVAL;

        vc4_perfmon_put(perfmon);
        return 0;
}

int vc4_perfmon_get_values_ioctl(struct drm_device *dev, void *data,
                                 struct drm_file *file_priv)
{
        struct vc4_dev *vc4 = to_vc4_dev(dev);
        struct vc4_file *vc4file = file_priv->driver_priv;
        struct drm_vc4_perfmon_get_values *req = data;
        struct vc4_perfmon *perfmon;
        int ret;

        if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
                return -ENODEV;

        if (!vc4->v3d) {
                DRM_DEBUG("Getting perfmon no VC4 V3D probed\n");
                return -ENODEV;
        }

        perfmon = vc4_perfmon_find(vc4file, req->id);
        if (!perfmon)
                return -EINVAL;

        if (copy_to_user(u64_to_user_ptr(req->values_ptr), perfmon->counters,
                         perfmon->ncounters * sizeof(u64)))
                ret = -EFAULT;
        else
                ret = 0;

        vc4_perfmon_put(perfmon);
        return ret;
}