// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
 */

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

#include <linux/debugfs.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/pm_opp.h>
#include <linux/sort.h>
#include <linux/clk.h>
#include <linux/bitmap.h>

#include "dpu_kms.h"
#include "dpu_trace.h"
#include "dpu_crtc.h"
#include "dpu_core_perf.h"

/**
 * enum dpu_perf_mode - performance tuning mode
 * @DPU_PERF_MODE_NORMAL: performance controlled by user mode client
 * @DPU_PERF_MODE_MINIMUM: performance bounded by minimum setting
 * @DPU_PERF_MODE_FIXED: performance bounded by fixed setting
 */
enum dpu_perf_mode {
        DPU_PERF_MODE_NORMAL,
        DPU_PERF_MODE_MINIMUM,
        DPU_PERF_MODE_FIXED,
        DPU_PERF_MODE_MAX
};

static struct dpu_kms *_dpu_crtc_get_kms(struct drm_crtc *crtc)
{
        struct msm_drm_private *priv;
        priv = crtc->dev->dev_private;
        return to_dpu_kms(priv->kms);
}

static void _dpu_core_perf_calc_crtc(struct dpu_kms *kms,
                struct drm_crtc *crtc,
                struct drm_crtc_state *state,
                struct dpu_core_perf_params *perf)
{
        struct dpu_crtc_state *dpu_cstate;

        if (!kms || !kms->catalog || !crtc || !state || !perf) {
                DPU_ERROR("invalid parameters\n");
                return;
        }

        dpu_cstate = to_dpu_crtc_state(state);
        memset(perf, 0, sizeof(struct dpu_core_perf_params));

        if (!dpu_cstate->bw_control) {
                perf->bw_ctl = kms->catalog->perf.max_bw_high *
                                        1000ULL;
                perf->max_per_pipe_ib = perf->bw_ctl;
                perf->core_clk_rate = kms->perf.max_core_clk_rate;
        } else if (kms->perf.perf_tune.mode == DPU_PERF_MODE_MINIMUM) {
                perf->bw_ctl = 0;
                perf->max_per_pipe_ib = 0;
                perf->core_clk_rate = 0;
        } else if (kms->perf.perf_tune.mode == DPU_PERF_MODE_FIXED) {
                perf->bw_ctl = kms->perf.fix_core_ab_vote;
                perf->max_per_pipe_ib = kms->perf.fix_core_ib_vote;
                perf->core_clk_rate = kms->perf.fix_core_clk_rate;
        }

        DPU_DEBUG(
                "crtc=%d clk_rate=%llu core_ib=%llu core_ab=%llu\n",
                        crtc->base.id, perf->core_clk_rate,
                        perf->max_per_pipe_ib, perf->bw_ctl);
}

int dpu_core_perf_crtc_check(struct drm_crtc *crtc,
                struct drm_crtc_state *state)
{
        u32 bw, threshold;
        u64 bw_sum_of_intfs = 0;
        enum dpu_crtc_client_type curr_client_type;
        struct dpu_crtc_state *dpu_cstate;
        struct drm_crtc *tmp_crtc;
        struct dpu_kms *kms;

        if (!crtc || !state) {
                DPU_ERROR("invalid crtc\n");
                return -EINVAL;
        }

        kms = _dpu_crtc_get_kms(crtc);
        if (!kms->catalog) {
                DPU_ERROR("invalid parameters\n");
                return 0;
        }

        /* we only need bandwidth check on real-time clients (interfaces) */
        if (dpu_crtc_get_client_type(crtc) == NRT_CLIENT)
                return 0;

        dpu_cstate = to_dpu_crtc_state(state);

        /* obtain new values */
        _dpu_core_perf_calc_crtc(kms, crtc, state, &dpu_cstate->new_perf);

        bw_sum_of_intfs = dpu_cstate->new_perf.bw_ctl;
        curr_client_type = dpu_crtc_get_client_type(crtc);

        drm_for_each_crtc(tmp_crtc, crtc->dev) {
                if (tmp_crtc->enabled &&
                    (dpu_crtc_get_client_type(tmp_crtc) ==
                                curr_client_type) && (tmp_crtc != crtc)) {
                        struct dpu_crtc_state *tmp_cstate =
                                to_dpu_crtc_state(tmp_crtc->state);

                        DPU_DEBUG("crtc:%d bw:%llu ctrl:%d\n",
                                tmp_crtc->base.id, tmp_cstate->new_perf.bw_ctl,
                                tmp_cstate->bw_control);
                        /*
                         * For bw check only use the bw if the
                         * atomic property has been already set
                         */
                        if (tmp_cstate->bw_control)
                                bw_sum_of_intfs += tmp_cstate->new_perf.bw_ctl;
                }

                /* convert bandwidth to kb */
                bw = DIV_ROUND_UP_ULL(bw_sum_of_intfs, 1000);
                DPU_DEBUG("calculated bandwidth=%uk\n", bw);

                threshold = kms->catalog->perf.max_bw_high;

                DPU_DEBUG("final threshold bw limit = %d\n", threshold);

                if (!dpu_cstate->bw_control) {
                        DPU_DEBUG("bypass bandwidth check\n");
                } else if (!threshold) {
                        DPU_ERROR("no bandwidth limits specified\n");
                        return -E2BIG;
                } else if (bw > threshold) {
                        DPU_ERROR("exceeds bandwidth: %ukb > %ukb\n", bw,
                                        threshold);
                        return -E2BIG;
                }
        }

        return 0;
}

static int _dpu_core_perf_crtc_update_bus(struct dpu_kms *kms,
                struct drm_crtc *crtc)
{
        struct dpu_core_perf_params perf = { 0 };
        enum dpu_crtc_client_type curr_client_type
                                        = dpu_crtc_get_client_type(crtc);
        struct drm_crtc *tmp_crtc;
        struct dpu_crtc_state *dpu_cstate;
        int ret = 0;

        drm_for_each_crtc(tmp_crtc, crtc->dev) {
                if (tmp_crtc->enabled &&
                        curr_client_type ==
                                dpu_crtc_get_client_type(tmp_crtc)) {
                        dpu_cstate = to_dpu_crtc_state(tmp_crtc->state);

                        perf.max_per_pipe_ib = max(perf.max_per_pipe_ib,
                                        dpu_cstate->new_perf.max_per_pipe_ib);

                        DPU_DEBUG("crtc=%d bw=%llu\n", tmp_crtc->base.id,
                                        dpu_cstate->new_perf.bw_ctl);
                }
        }
        return ret;
}

/**
 * @dpu_core_perf_crtc_release_bw() - request zero bandwidth
 * @crtc - pointer to a crtc
 *
 * Function checks a state variable for the crtc, if all pending commit
 * requests are done, meaning no more bandwidth is needed, release
 * bandwidth request.
 */
void dpu_core_perf_crtc_release_bw(struct drm_crtc *crtc)
{
        struct dpu_crtc *dpu_crtc;
        struct dpu_kms *kms;

        if (!crtc) {
                DPU_ERROR("invalid crtc\n");
                return;
        }

        kms = _dpu_crtc_get_kms(crtc);
        if (!kms->catalog) {
                DPU_ERROR("invalid kms\n");
                return;
        }

        dpu_crtc = to_dpu_crtc(crtc);

        if (atomic_dec_return(&kms->bandwidth_ref) > 0)
                return;

        /* Release the bandwidth */
        if (kms->perf.enable_bw_release) {
                trace_dpu_cmd_release_bw(crtc->base.id);
                DPU_DEBUG("Release BW crtc=%d\n", crtc->base.id);
                dpu_crtc->cur_perf.bw_ctl = 0;
                _dpu_core_perf_crtc_update_bus(kms, crtc);
        }
}

static int _dpu_core_perf_set_core_clk_rate(struct dpu_kms *kms, u64 rate)
{
        struct dss_clk *core_clk = kms->perf.core_clk;

        if (core_clk->max_rate && (rate > core_clk->max_rate))
                rate = core_clk->max_rate;

        core_clk->rate = rate;
        return dev_pm_opp_set_rate(&kms->pdev->dev, core_clk->rate);
}

static u64 _dpu_core_perf_get_core_clk_rate(struct dpu_kms *kms)
{
        u64 clk_rate = kms->perf.perf_tune.min_core_clk;
        struct drm_crtc *crtc;
        struct dpu_crtc_state *dpu_cstate;

        drm_for_each_crtc(crtc, kms->dev) {
                if (crtc->enabled) {
                        dpu_cstate = to_dpu_crtc_state(crtc->state);
                        clk_rate = max(dpu_cstate->new_perf.core_clk_rate,
                                                        clk_rate);
                        clk_rate = clk_round_rate(kms->perf.core_clk->clk,
                                        clk_rate);
                }
        }

        if (kms->perf.perf_tune.mode == DPU_PERF_MODE_FIXED)
                clk_rate = kms->perf.fix_core_clk_rate;

        DPU_DEBUG("clk:%llu\n", clk_rate);

        return clk_rate;
}

int dpu_core_perf_crtc_update(struct drm_crtc *crtc,
                int params_changed, bool stop_req)
{
        struct dpu_core_perf_params *new, *old;
        bool update_bus = false, update_clk = false;
        u64 clk_rate = 0;
        struct dpu_crtc *dpu_crtc;
        struct dpu_crtc_state *dpu_cstate;
        struct dpu_kms *kms;
        int ret;

        if (!crtc) {
                DPU_ERROR("invalid crtc\n");
                return -EINVAL;
        }

        kms = _dpu_crtc_get_kms(crtc);
        if (!kms->catalog) {
                DPU_ERROR("invalid kms\n");
                return -EINVAL;
        }

        dpu_crtc = to_dpu_crtc(crtc);
        dpu_cstate = to_dpu_crtc_state(crtc->state);

        DPU_DEBUG("crtc:%d stop_req:%d core_clk:%llu\n",
                        crtc->base.id, stop_req, kms->perf.core_clk_rate);

        old = &dpu_crtc->cur_perf;
        new = &dpu_cstate->new_perf;

        if (crtc->enabled && !stop_req) {
                /*
                 * cases for bus bandwidth update.
                 * 1. new bandwidth vote - "ab or ib vote" is higher
                 *    than current vote for update request.
                 * 2. new bandwidth vote - "ab or ib vote" is lower
                 *    than current vote at end of commit or stop.
                 */
                if ((params_changed && ((new->bw_ctl > old->bw_ctl) ||
                        (new->max_per_pipe_ib > old->max_per_pipe_ib))) ||
                        (!params_changed && ((new->bw_ctl < old->bw_ctl) ||
                        (new->max_per_pipe_ib < old->max_per_pipe_ib)))) {
                        DPU_DEBUG("crtc=%d p=%d new_bw=%llu,old_bw=%llu\n",
                                crtc->base.id, params_changed,
                                new->bw_ctl, old->bw_ctl);
                        old->bw_ctl = new->bw_ctl;
                        old->max_per_pipe_ib = new->max_per_pipe_ib;
                        update_bus = true;
                }

                if ((params_changed &&
                        (new->core_clk_rate > old->core_clk_rate)) ||
                        (!params_changed &&
                        (new->core_clk_rate < old->core_clk_rate))) {
                        old->core_clk_rate = new->core_clk_rate;
                        update_clk = true;
                }
        } else {
                DPU_DEBUG("crtc=%d disable\n", crtc->base.id);
                memset(old, 0, sizeof(*old));
                memset(new, 0, sizeof(*new));
                update_bus = true;
                update_clk = true;
        }

        trace_dpu_perf_crtc_update(crtc->base.id, new->bw_ctl,
                new->core_clk_rate, stop_req, update_bus, update_clk);

        if (update_bus) {
                ret = _dpu_core_perf_crtc_update_bus(kms, crtc);
                if (ret) {
                        DPU_ERROR("crtc-%d: failed to update bus bw vote\n",
                                  crtc->base.id);
                        return ret;
                }
        }

        /*
         * Update the clock after bandwidth vote to ensure
         * bandwidth is available before clock rate is increased.
         */
        if (update_clk) {
                clk_rate = _dpu_core_perf_get_core_clk_rate(kms);

                trace_dpu_core_perf_update_clk(kms->dev, stop_req, clk_rate);

                ret = _dpu_core_perf_set_core_clk_rate(kms, clk_rate);
                if (ret) {
                        DPU_ERROR("failed to set %s clock rate %llu\n",
                                        kms->perf.core_clk->clk_name, clk_rate);
                        return ret;
                }

                kms->perf.core_clk_rate = clk_rate;
                DPU_DEBUG("update clk rate = %lld HZ\n", clk_rate);
        }
        return 0;
}

#ifdef CONFIG_DEBUG_FS

static ssize_t _dpu_core_perf_mode_write(struct file *file,
                    const char __user *user_buf, size_t count, loff_t *ppos)
{
        struct dpu_core_perf *perf = file->private_data;
        struct dpu_perf_cfg *cfg = &perf->catalog->perf;
        u32 perf_mode = 0;
        int ret;

        ret = kstrtouint_from_user(user_buf, count, 0, &perf_mode);
        if (ret)
                return ret;

        if (perf_mode >= DPU_PERF_MODE_MAX)
                return -EINVAL;

        if (perf_mode == DPU_PERF_MODE_FIXED) {
                DRM_INFO("fix performance mode\n");
        } else if (perf_mode == DPU_PERF_MODE_MINIMUM) {
                /* run the driver with max clk and BW vote */
                perf->perf_tune.min_core_clk = perf->max_core_clk_rate;
                perf->perf_tune.min_bus_vote =
                                (u64) cfg->max_bw_high * 1000;
                DRM_INFO("minimum performance mode\n");
        } else if (perf_mode == DPU_PERF_MODE_NORMAL) {
                /* reset the perf tune params to 0 */
                perf->perf_tune.min_core_clk = 0;
                perf->perf_tune.min_bus_vote = 0;
                DRM_INFO("normal performance mode\n");
        }
        perf->perf_tune.mode = perf_mode;

        return count;
}

static ssize_t _dpu_core_perf_mode_read(struct file *file,
                        char __user *buff, size_t count, loff_t *ppos)
{
        struct dpu_core_perf *perf = file->private_data;
        int len;
        char buf[128];

        len = scnprintf(buf, sizeof(buf),
                        "mode %d min_mdp_clk %llu min_bus_vote %llu\n",
                        perf->perf_tune.mode,
                        perf->perf_tune.min_core_clk,
                        perf->perf_tune.min_bus_vote);

        return simple_read_from_buffer(buff, count, ppos, buf, len);
}

static const struct file_operations dpu_core_perf_mode_fops = {
        .open = simple_open,
        .read = _dpu_core_perf_mode_read,
        .write = _dpu_core_perf_mode_write,
};

int dpu_core_perf_debugfs_init(struct dpu_kms *dpu_kms, struct dentry *parent)
{
        struct dpu_core_perf *perf = &dpu_kms->perf;
        struct dpu_mdss_cfg *catalog = perf->catalog;
        struct dentry *entry;

        entry = debugfs_create_dir("core_perf", parent);

        debugfs_create_u64("max_core_clk_rate", 0600, entry,
                        &perf->max_core_clk_rate);
        debugfs_create_u64("core_clk_rate", 0600, entry,
                        &perf->core_clk_rate);
        debugfs_create_u32("enable_bw_release", 0600, entry,
                        (u32 *)&perf->enable_bw_release);
        debugfs_create_u32("threshold_low", 0600, entry,
                        (u32 *)&catalog->perf.max_bw_low);
        debugfs_create_u32("threshold_high", 0600, entry,
                        (u32 *)&catalog->perf.max_bw_high);
        debugfs_create_u32("min_core_ib", 0600, entry,
                        (u32 *)&catalog->perf.min_core_ib);
        debugfs_create_u32("min_llcc_ib", 0600, entry,
                        (u32 *)&catalog->perf.min_llcc_ib);
        debugfs_create_u32("min_dram_ib", 0600, entry,
                        (u32 *)&catalog->perf.min_dram_ib);
        debugfs_create_file("perf_mode", 0600, entry,
                        (u32 *)perf, &dpu_core_perf_mode_fops);
        debugfs_create_u64("fix_core_clk_rate", 0600, entry,
                        &perf->fix_core_clk_rate);
        debugfs_create_u64("fix_core_ib_vote", 0600, entry,
                        &perf->fix_core_ib_vote);
        debugfs_create_u64("fix_core_ab_vote", 0600, entry,
                        &perf->fix_core_ab_vote);

        return 0;
}
#endif

void dpu_core_perf_destroy(struct dpu_core_perf *perf)
{
        if (!perf) {
                DPU_ERROR("invalid parameters\n");
                return;
        }

        perf->max_core_clk_rate = 0;
        perf->core_clk = NULL;
        perf->catalog = NULL;
        perf->dev = NULL;
}

int dpu_core_perf_init(struct dpu_core_perf *perf,
                struct drm_device *dev,
                struct dpu_mdss_cfg *catalog,
                struct dss_clk *core_clk)
{
        perf->dev = dev;
        perf->catalog = catalog;
        perf->core_clk = core_clk;

        perf->max_core_clk_rate = core_clk->max_rate;
        if (!perf->max_core_clk_rate) {
                DPU_DEBUG("optional max core clk rate, use default\n");
                perf->max_core_clk_rate = DPU_PERF_DEFAULT_MAX_CORE_CLK_RATE;
        }

        return 0;
}