// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2017 Etnaviv Project
 */

#include <linux/moduleparam.h>

#include "etnaviv_drv.h"
#include "etnaviv_dump.h"
#include "etnaviv_gem.h"
#include "etnaviv_gpu.h"
#include "etnaviv_sched.h"
#include "state.xml.h"

static int etnaviv_job_hang_limit = 0;
module_param_named(job_hang_limit, etnaviv_job_hang_limit, int , 0444);
static int etnaviv_hw_jobs_limit = 4;
module_param_named(hw_job_limit, etnaviv_hw_jobs_limit, int , 0444);

static struct dma_fence *
etnaviv_sched_dependency(struct drm_sched_job *sched_job,
                         struct drm_sched_entity *entity)
{
        struct etnaviv_gem_submit *submit = to_etnaviv_submit(sched_job);
        struct dma_fence *fence;
        int i;

        if (unlikely(submit->in_fence)) {
                fence = submit->in_fence;
                submit->in_fence = NULL;

                if (!dma_fence_is_signaled(fence))
                        return fence;

                dma_fence_put(fence);
        }

        for (i = 0; i < submit->nr_bos; i++) {
                struct etnaviv_gem_submit_bo *bo = &submit->bos[i];
                int j;

                if (bo->excl) {
                        fence = bo->excl;
                        bo->excl = NULL;

                        if (!dma_fence_is_signaled(fence))
                                return fence;

                        dma_fence_put(fence);
                }

                for (j = 0; j < bo->nr_shared; j++) {
                        if (!bo->shared[j])
                                continue;

                        fence = bo->shared[j];
                        bo->shared[j] = NULL;

                        if (!dma_fence_is_signaled(fence))
                                return fence;

                        dma_fence_put(fence);
                }
                kfree(bo->shared);
                bo->nr_shared = 0;
                bo->shared = NULL;
        }

        return NULL;
}

static struct dma_fence *etnaviv_sched_run_job(struct drm_sched_job *sched_job)
{
        struct etnaviv_gem_submit *submit = to_etnaviv_submit(sched_job);
        struct dma_fence *fence = NULL;

        if (likely(!sched_job->s_fence->finished.error))
                fence = etnaviv_gpu_submit(submit);
        else
                dev_dbg(submit->gpu->dev, "skipping bad job\n");

        return fence;
}

static enum drm_gpu_sched_stat etnaviv_sched_timedout_job(struct drm_sched_job
                                                          *sched_job)
{
        struct etnaviv_gem_submit *submit = to_etnaviv_submit(sched_job);
        struct etnaviv_gpu *gpu = submit->gpu;
        u32 dma_addr;
        int change;

        /* block scheduler */
        drm_sched_stop(&gpu->sched, sched_job);

        /*
         * If the GPU managed to complete this jobs fence, the timout is
         * spurious. Bail out.
         */
        if (dma_fence_is_signaled(submit->out_fence))
                goto out_no_timeout;

        /*
         * If the GPU is still making forward progress on the front-end (which
         * should never loop) we shift out the timeout to give it a chance to
         * finish the job.
         */
        dma_addr = gpu_read(gpu, VIVS_FE_DMA_ADDRESS);
        change = dma_addr - gpu->hangcheck_dma_addr;
        if (change < 0 || change > 16) {
                gpu->hangcheck_dma_addr = dma_addr;
                goto out_no_timeout;
        }

        if(sched_job)
                drm_sched_increase_karma(sched_job);

        /* get the GPU back into the init state */
        etnaviv_core_dump(submit);
        etnaviv_gpu_recover_hang(gpu);

        drm_sched_resubmit_jobs(&gpu->sched);

        drm_sched_start(&gpu->sched, true);
        return DRM_GPU_SCHED_STAT_NOMINAL;

out_no_timeout:
        /* restart scheduler after GPU is usable again */
        drm_sched_start(&gpu->sched, true);
        return DRM_GPU_SCHED_STAT_NOMINAL;
}

static void etnaviv_sched_free_job(struct drm_sched_job *sched_job)
{
        struct etnaviv_gem_submit *submit = to_etnaviv_submit(sched_job);

        drm_sched_job_cleanup(sched_job);

        etnaviv_submit_put(submit);
}

static const struct drm_sched_backend_ops etnaviv_sched_ops = {
        .dependency = etnaviv_sched_dependency,
        .run_job = etnaviv_sched_run_job,
        .timedout_job = etnaviv_sched_timedout_job,
        .free_job = etnaviv_sched_free_job,
};

int etnaviv_sched_push_job(struct drm_sched_entity *sched_entity,
                           struct etnaviv_gem_submit *submit)
{
        int ret = 0;

        /*
         * Hold the fence lock across the whole operation to avoid jobs being
         * pushed out of order with regard to their sched fence seqnos as
         * allocated in drm_sched_job_init.
         */
        mutex_lock(&submit->gpu->fence_lock);

        ret = drm_sched_job_init(&submit->sched_job, sched_entity,
                                 submit->ctx);
        if (ret)
                goto out_unlock;

        submit->out_fence = dma_fence_get(&submit->sched_job.s_fence->finished);
        submit->out_fence_id = idr_alloc_cyclic(&submit->gpu->fence_idr,
                                                submit->out_fence, 0,
                                                INT_MAX, GFP_KERNEL);
        if (submit->out_fence_id < 0) {
                drm_sched_job_cleanup(&submit->sched_job);
                ret = -ENOMEM;
                goto out_unlock;
        }

        /* the scheduler holds on to the job now */
        kref_get(&submit->refcount);

        drm_sched_entity_push_job(&submit->sched_job, sched_entity);

out_unlock:
        mutex_unlock(&submit->gpu->fence_lock);

        return ret;
}

int etnaviv_sched_init(struct etnaviv_gpu *gpu)
{
        int ret;

        ret = drm_sched_init(&gpu->sched, &etnaviv_sched_ops,
                             etnaviv_hw_jobs_limit, etnaviv_job_hang_limit,
                             msecs_to_jiffies(500), NULL, NULL,
                             dev_name(gpu->dev));
        if (ret)
                return ret;

        return 0;
}

void etnaviv_sched_fini(struct etnaviv_gpu *gpu)
{
        drm_sched_fini(&gpu->sched);
}