// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
 */

#define pr_fmt(fmt)     "[drm:%s:%d] " fmt, __func__, __LINE__

#include "msm_disp_snapshot.h"

static ssize_t __maybe_unused disp_devcoredump_read(char *buffer, loff_t offset,
                size_t count, void *data, size_t datalen)
{
        struct drm_print_iterator iter;
        struct drm_printer p;
        struct msm_disp_state *disp_state;

        disp_state = data;

        iter.data = buffer;
        iter.offset = 0;
        iter.start = offset;
        iter.remain = count;

        p = drm_coredump_printer(&iter);

        msm_disp_state_print(disp_state, &p);

        return count - iter.remain;
}

struct msm_disp_state *
msm_disp_snapshot_state_sync(struct msm_kms *kms)
{
        struct drm_device *drm_dev = kms->dev;
        struct msm_disp_state *disp_state;

        WARN_ON(!mutex_is_locked(&kms->dump_mutex));

        disp_state = kzalloc_obj(struct msm_disp_state);
        if (!disp_state)
                return ERR_PTR(-ENOMEM);

        disp_state->dev = drm_dev->dev;
        disp_state->drm_dev = drm_dev;

        INIT_LIST_HEAD(&disp_state->blocks);

        msm_disp_snapshot_capture_state(disp_state);

        return disp_state;
}

static void _msm_disp_snapshot_work(struct kthread_work *work)
{
        struct msm_kms *kms = container_of(work, struct msm_kms, dump_work);
        struct msm_disp_state *disp_state;
        struct drm_printer p;

        /* Serialize dumping here */
        mutex_lock(&kms->dump_mutex);
        disp_state = msm_disp_snapshot_state_sync(kms);
        mutex_unlock(&kms->dump_mutex);

        if (IS_ERR(disp_state))
                return;

        if (MSM_DISP_SNAPSHOT_DUMP_IN_CONSOLE) {
                p = drm_info_printer(disp_state->drm_dev->dev);
                msm_disp_state_print(disp_state, &p);
        }

        /*
         * If COREDUMP is disabled, the stub will call the free function.
         * If there is a codedump pending for the device, the dev_coredumpm()
         * will also free new coredump state.
         */
        dev_coredumpm(disp_state->dev, THIS_MODULE, disp_state, 0, GFP_KERNEL,
                        disp_devcoredump_read, msm_disp_state_free);
}

void msm_disp_snapshot_state(struct drm_device *drm_dev)
{
        struct msm_drm_private *priv;
        struct msm_kms *kms;

        if (!drm_dev) {
                DRM_ERROR("invalid params\n");
                return;
        }

        priv = drm_dev->dev_private;
        kms = priv->kms;

        kthread_queue_work(kms->dump_worker, &kms->dump_work);
}

int msm_disp_snapshot_init(struct drm_device *drm_dev)
{
        struct msm_drm_private *priv;
        struct msm_kms *kms;

        if (!drm_dev) {
                DRM_ERROR("invalid params\n");
                return -EINVAL;
        }

        priv = drm_dev->dev_private;
        kms = priv->kms;

        mutex_init(&kms->dump_mutex);

        kms->dump_worker = kthread_run_worker(0, "%s", "disp_snapshot");
        if (IS_ERR(kms->dump_worker))
                DRM_ERROR("failed to create disp state task\n");

        kthread_init_work(&kms->dump_work, _msm_disp_snapshot_work);

        return 0;
}

void msm_disp_snapshot_destroy(struct drm_device *drm_dev)
{
        struct msm_kms *kms;
        struct msm_drm_private *priv;

        if (!drm_dev) {
                DRM_ERROR("invalid params\n");
                return;
        }

        priv = drm_dev->dev_private;
        kms = priv->kms;

        if (kms->dump_worker)
                kthread_destroy_worker(kms->dump_worker);

        mutex_destroy(&kms->dump_mutex);
}