/*
 * Copyright 2012 Red Hat Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Ben Skeggs
 */
#include <core/engine.h>
#include <core/device.h>
#include <core/option.h>

#include <subdev/fb.h>

bool
nvkm_engine_chsw_load(struct nvkm_engine *engine)
{
        if (engine->func->chsw_load)
                return engine->func->chsw_load(engine);
        return false;
}

void
nvkm_engine_unref(struct nvkm_engine **pengine)
{
        struct nvkm_engine *engine = *pengine;
        if (engine) {
                if (refcount_dec_and_mutex_lock(&engine->use.refcount, &engine->use.mutex)) {
                        nvkm_subdev_fini(&engine->subdev, false);
                        engine->use.enabled = false;
                        mutex_unlock(&engine->use.mutex);
                }
                *pengine = NULL;
        }
}

struct nvkm_engine *
nvkm_engine_ref(struct nvkm_engine *engine)
{
        int ret;
        if (engine) {
                if (!refcount_inc_not_zero(&engine->use.refcount)) {
                        mutex_lock(&engine->use.mutex);
                        if (!refcount_inc_not_zero(&engine->use.refcount)) {
                                engine->use.enabled = true;
                                if ((ret = nvkm_subdev_init(&engine->subdev))) {
                                        engine->use.enabled = false;
                                        mutex_unlock(&engine->use.mutex);
                                        return ERR_PTR(ret);
                                }
                                refcount_set(&engine->use.refcount, 1);
                        }
                        mutex_unlock(&engine->use.mutex);
                }
        }
        return engine;
}

void
nvkm_engine_tile(struct nvkm_engine *engine, int region)
{
        struct nvkm_fb *fb = engine->subdev.device->fb;
        if (engine->func->tile)
                engine->func->tile(engine, region, &fb->tile.region[region]);
}

static void
nvkm_engine_intr(struct nvkm_subdev *subdev)
{
        struct nvkm_engine *engine = nvkm_engine(subdev);
        if (engine->func->intr)
                engine->func->intr(engine);
}

static int
nvkm_engine_info(struct nvkm_subdev *subdev, u64 mthd, u64 *data)
{
        struct nvkm_engine *engine = nvkm_engine(subdev);
        if (engine->func->info) {
                if (!IS_ERR((engine = nvkm_engine_ref(engine)))) {
                        int ret = engine->func->info(engine, mthd, data);
                        nvkm_engine_unref(&engine);
                        return ret;
                }
                return PTR_ERR(engine);
        }
        return -ENOSYS;
}

static int
nvkm_engine_fini(struct nvkm_subdev *subdev, bool suspend)
{
        struct nvkm_engine *engine = nvkm_engine(subdev);
        if (engine->func->fini)
                return engine->func->fini(engine, suspend);
        return 0;
}

static int
nvkm_engine_init(struct nvkm_subdev *subdev)
{
        struct nvkm_engine *engine = nvkm_engine(subdev);
        struct nvkm_fb *fb = subdev->device->fb;
        int ret = 0, i;
        s64 time;

        if (!engine->use.enabled) {
                nvkm_trace(subdev, "init skipped, engine has no users\n");
                return ret;
        }

        if (engine->func->oneinit && !engine->subdev.oneinit) {
                nvkm_trace(subdev, "one-time init running...\n");
                time = ktime_to_us(ktime_get());
                ret = engine->func->oneinit(engine);
                if (ret) {
                        nvkm_trace(subdev, "one-time init failed, %d\n", ret);
                        return ret;
                }

                engine->subdev.oneinit = true;
                time = ktime_to_us(ktime_get()) - time;
                nvkm_trace(subdev, "one-time init completed in %lldus\n", time);
        }

        if (engine->func->init)
                ret = engine->func->init(engine);

        for (i = 0; fb && i < fb->tile.regions; i++)
                nvkm_engine_tile(engine, i);
        return ret;
}

static int
nvkm_engine_preinit(struct nvkm_subdev *subdev)
{
        struct nvkm_engine *engine = nvkm_engine(subdev);
        if (engine->func->preinit)
                engine->func->preinit(engine);
        return 0;
}

static void *
nvkm_engine_dtor(struct nvkm_subdev *subdev)
{
        struct nvkm_engine *engine = nvkm_engine(subdev);
        if (engine->func->dtor)
                return engine->func->dtor(engine);
        mutex_destroy(&engine->use.mutex);
        return engine;
}

const struct nvkm_subdev_func
nvkm_engine = {
        .dtor = nvkm_engine_dtor,
        .preinit = nvkm_engine_preinit,
        .init = nvkm_engine_init,
        .fini = nvkm_engine_fini,
        .info = nvkm_engine_info,
        .intr = nvkm_engine_intr,
};

int
nvkm_engine_ctor(const struct nvkm_engine_func *func, struct nvkm_device *device,
                 enum nvkm_subdev_type type, int inst, bool enable, struct nvkm_engine *engine)
{
        nvkm_subdev_ctor(&nvkm_engine, device, type, inst, &engine->subdev);
        engine->func = func;
        refcount_set(&engine->use.refcount, 0);
        mutex_init(&engine->use.mutex);

        if (!nvkm_boolopt(device->cfgopt, engine->subdev.name, enable)) {
                nvkm_debug(&engine->subdev, "disabled\n");
                return -ENODEV;
        }

        spin_lock_init(&engine->lock);
        return 0;
}

int
nvkm_engine_new_(const struct nvkm_engine_func *func, struct nvkm_device *device,
                 enum nvkm_subdev_type type, int inst, bool enable,
                 struct nvkm_engine **pengine)
{
        if (!(*pengine = kzalloc(sizeof(**pengine), GFP_KERNEL)))
                return -ENOMEM;
        return nvkm_engine_ctor(func, device, type, inst, enable, *pengine);
}