// 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
 * @DPU_PERF_MODE_MAX: maximum value, used for error checking
 */
enum dpu_perf_mode {
        DPU_PERF_MODE_NORMAL,
        DPU_PERF_MODE_MINIMUM,
        DPU_PERF_MODE_FIXED,
        DPU_PERF_MODE_MAX
};

/**
 * dpu_core_perf_adjusted_mode_clk - Adjust given mode clock rate according to
 *   the perf clock factor.
 * @crtc_clk_rate - Unadjusted mode clock rate
 * @perf_cfg: performance configuration
 */
u64 dpu_core_perf_adjusted_mode_clk(u64 mode_clk_rate,
                                    const struct dpu_perf_cfg *perf_cfg)
{
        u32 clk_factor;

        clk_factor = perf_cfg->clk_inefficiency_factor;
        if (clk_factor) {
                mode_clk_rate *= clk_factor;
                do_div(mode_clk_rate, 100);
        }

        return mode_clk_rate;
}

/**
 * _dpu_core_perf_calc_bw() - to calculate BW per crtc
 * @perf_cfg: performance configuration
 * @crtc: pointer to a crtc
 * Return: returns aggregated BW for all planes in crtc.
 */
static u64 _dpu_core_perf_calc_bw(const struct dpu_perf_cfg *perf_cfg,
                struct drm_crtc *crtc)
{
        struct drm_plane *plane;
        struct dpu_plane_state *pstate;
        u64 crtc_plane_bw = 0;
        u32 bw_factor;

        drm_atomic_crtc_for_each_plane(plane, crtc) {
                pstate = to_dpu_plane_state(plane->state);
                if (!pstate)
                        continue;

                crtc_plane_bw += pstate->plane_fetch_bw;
        }

        bw_factor = perf_cfg->bw_inefficiency_factor;
        if (bw_factor) {
                crtc_plane_bw *= bw_factor;
                do_div(crtc_plane_bw, 100);
        }

        return crtc_plane_bw;
}

/**
 * _dpu_core_perf_calc_clk() - to calculate clock per crtc
 * @perf_cfg: performance configuration
 * @crtc: pointer to a crtc
 * @state: pointer to a crtc state
 * Return: returns max clk for all planes in crtc.
 */
static u64 _dpu_core_perf_calc_clk(const struct dpu_perf_cfg *perf_cfg,
                struct drm_crtc *crtc, struct drm_crtc_state *state)
{
        struct drm_plane *plane;
        struct dpu_plane_state *pstate;
        struct drm_display_mode *mode;
        u64 mode_clk;

        mode = &state->adjusted_mode;

        mode_clk = (u64)mode->vtotal * mode->hdisplay * drm_mode_vrefresh(mode);

        drm_atomic_crtc_for_each_plane(plane, crtc) {
                pstate = to_dpu_plane_state(plane->state);
                if (!pstate)
                        continue;

                mode_clk = max(pstate->plane_clk, mode_clk);
        }

        return dpu_core_perf_adjusted_mode_clk(mode_clk, perf_cfg);
}

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(const struct dpu_core_perf *core_perf,
                                     struct drm_crtc *crtc,
                                     struct drm_crtc_state *state,
                                     struct dpu_core_perf_params *perf)
{
        const struct dpu_perf_cfg *perf_cfg = core_perf->perf_cfg;

        if (!perf_cfg || !crtc || !state || !perf) {
                DPU_ERROR("invalid parameters\n");
                return;
        }

        perf->bw_ctl = _dpu_core_perf_calc_bw(perf_cfg, crtc);
        perf->max_per_pipe_ib = perf_cfg->min_dram_ib;
        perf->core_clk_rate = _dpu_core_perf_calc_clk(perf_cfg, crtc, state);
        DRM_DEBUG_ATOMIC(
                "crtc=%d clk_rate=%llu core_ib=%u core_ab=%u\n",
                        crtc->base.id, perf->core_clk_rate,
                        perf->max_per_pipe_ib,
                        (u32)DIV_ROUND_UP_ULL(perf->bw_ctl, 1000));
}

static void dpu_core_perf_aggregate(struct drm_device *ddev,
                                    enum dpu_crtc_client_type curr_client_type,
                                    struct dpu_core_perf_params *perf)
{
        struct dpu_crtc_state *dpu_cstate;
        struct drm_crtc *tmp_crtc;

        drm_for_each_crtc(tmp_crtc, ddev) {
                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);

                        perf->bw_ctl += dpu_cstate->new_perf.bw_ctl;

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

/**
 * dpu_core_perf_crtc_check - validate performance of the given crtc state
 * @crtc: Pointer to crtc
 * @state: Pointer to new crtc state
 * return: zero if success, or error code otherwise
 */
int dpu_core_perf_crtc_check(struct drm_crtc *crtc,
                struct drm_crtc_state *state)
{
        u32 bw, threshold;
        struct dpu_crtc_state *dpu_cstate;
        struct dpu_kms *kms;
        struct dpu_core_perf_params perf = { 0 };

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

        kms = _dpu_crtc_get_kms(crtc);

        /* 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->perf, crtc, state, &dpu_cstate->new_perf);

        dpu_core_perf_aggregate(crtc->dev, dpu_crtc_get_client_type(crtc), &perf);

        /* convert bandwidth to kb */
        bw = DIV_ROUND_UP_ULL(perf.bw_ctl, 1000);
        DRM_DEBUG_ATOMIC("calculated bandwidth=%uk\n", bw);

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

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

        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 };
        int i, ret = 0;
        u32 avg_bw;
        u32 peak_bw;

        if (!kms->num_paths)
                return 0;

        if (kms->perf.perf_tune.mode == DPU_PERF_MODE_MINIMUM) {
                avg_bw = 0;
                peak_bw = 0;
        } else if (kms->perf.perf_tune.mode == DPU_PERF_MODE_FIXED) {
                avg_bw = kms->perf.fix_core_ab_vote;
                peak_bw = kms->perf.fix_core_ib_vote;
        } else {
                dpu_core_perf_aggregate(crtc->dev, dpu_crtc_get_client_type(crtc), &perf);

                avg_bw = div_u64(perf.bw_ctl, 1000); /*Bps_to_icc*/
                peak_bw = perf.max_per_pipe_ib;
        }

        avg_bw /= kms->num_paths;

        for (i = 0; i < kms->num_paths; i++)
                icc_set_bw(kms->path[i], avg_bw, peak_bw);

        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);
        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);
                DRM_DEBUG_ATOMIC("Release BW crtc=%d\n", crtc->base.id);
                dpu_crtc->cur_perf.bw_ctl = 0;
                _dpu_core_perf_crtc_update_bus(kms, crtc);
        }
}

static u64 _dpu_core_perf_get_core_clk_rate(struct dpu_kms *kms)
{
        u64 clk_rate;
        struct drm_crtc *crtc;
        struct dpu_crtc_state *dpu_cstate;

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

        if (kms->perf.perf_tune.mode == DPU_PERF_MODE_MINIMUM)
                return kms->perf.max_core_clk_rate;

        clk_rate = 0;
        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);
                }
        }

        return clk_rate;
}

/**
 * dpu_core_perf_crtc_update - update performance of the given crtc
 * @crtc: Pointer to crtc
 * @params_changed: true if crtc parameters are modified
 * return: zero if success, or error code otherwise
 */
int dpu_core_perf_crtc_update(struct drm_crtc *crtc,
                              int params_changed)
{
        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);

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

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

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

        if (crtc->enabled) {
                /*
                 * 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)))) {
                        DRM_DEBUG_ATOMIC("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 {
                DRM_DEBUG_ATOMIC("crtc=%d disable\n", crtc->base.id);
                memset(old, 0, sizeof(*old));
                update_bus = true;
                update_clk = true;
        }

        trace_dpu_perf_crtc_update(crtc->base.id, new->bw_ctl,
                new->core_clk_rate, !crtc->enabled, 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);

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

                trace_dpu_core_perf_update_clk(kms->dev, !crtc->enabled, clk_rate);

                clk_rate = min(clk_rate, kms->perf.max_core_clk_rate);
                ret = dev_pm_opp_set_rate(&kms->pdev->dev, clk_rate);
                if (ret) {
                        DPU_ERROR("failed to set core clock rate %llu\n", clk_rate);
                        return ret;
                }

                kms->perf.core_clk_rate = clk_rate;
                DRM_DEBUG_ATOMIC("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;
        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 */
                DRM_INFO("minimum performance mode\n");
        } else if (perf_mode == DPU_PERF_MODE_NORMAL) {
                /* reset the perf tune params to 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\n",
                        perf->perf_tune.mode);

        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,
};

/**
 * dpu_core_perf_debugfs_init - initialize debugfs for core performance context
 * @dpu_kms: Pointer to the dpu_kms struct
 * @parent: Pointer to parent debugfs
 */
int dpu_core_perf_debugfs_init(struct dpu_kms *dpu_kms, struct dentry *parent)
{
        struct dpu_core_perf *perf = &dpu_kms->perf;
        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("low_core_ab", 0400, entry,
                        (u32 *)&perf->perf_cfg->max_bw_low);
        debugfs_create_u32("max_core_ab", 0400, entry,
                        (u32 *)&perf->perf_cfg->max_bw_high);
        debugfs_create_u32("min_core_ib", 0400, entry,
                        (u32 *)&perf->perf_cfg->min_core_ib);
        debugfs_create_u32("min_llcc_ib", 0400, entry,
                        (u32 *)&perf->perf_cfg->min_llcc_ib);
        debugfs_create_u32("min_dram_ib", 0400, entry,
                        (u32 *)&perf->perf_cfg->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_u32("fix_core_ib_vote", 0600, entry,
                        &perf->fix_core_ib_vote);
        debugfs_create_u32("fix_core_ab_vote", 0600, entry,
                        &perf->fix_core_ab_vote);

        return 0;
}
#endif

/**
 * dpu_core_perf_init - initialize the given core performance context
 * @perf: Pointer to core performance context
 * @perf_cfg: Pointer to platform performance configuration
 * @max_core_clk_rate: Maximum core clock rate
 */
int dpu_core_perf_init(struct dpu_core_perf *perf,
                const struct dpu_perf_cfg *perf_cfg,
                unsigned long max_core_clk_rate)
{
        perf->perf_cfg = perf_cfg;
        perf->max_core_clk_rate = max_core_clk_rate;

        return 0;
}