// 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/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 msm_dss_clk_set_rate(core_clk, 1);
}

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;
}