/*
 * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#define pr_fmt(fmt)     "[drm:%s] " fmt, __func__
#include "dpu_kms.h"
#include "dpu_hw_lm.h"
#include "dpu_hw_ctl.h"
#include "dpu_hw_pingpong.h"
#include "dpu_hw_intf.h"
#include "dpu_encoder.h"
#include "dpu_trace.h"

#define RESERVED_BY_OTHER(h, r)  \
                ((h)->enc_id && (h)->enc_id != r)

/**
 * struct dpu_rm_requirements - Reservation requirements parameter bundle
 * @topology:  selected topology for the display
 * @hw_res:        Hardware resources required as reported by the encoders
 */
struct dpu_rm_requirements {
        struct msm_display_topology topology;
        struct dpu_encoder_hw_resources hw_res;
};


/**
 * struct dpu_rm_hw_blk - hardware block tracking list member
 * @list:       List head for list of all hardware blocks tracking items
 * @id:         Hardware ID number, within it's own space, ie. LM_X
 * @enc_id:     Encoder id to which this blk is binded
 * @hw:         Pointer to the hardware register access object for this block
 */
struct dpu_rm_hw_blk {
        struct list_head list;
        uint32_t id;
        uint32_t enc_id;
        struct dpu_hw_blk *hw;
};

void dpu_rm_init_hw_iter(
                struct dpu_rm_hw_iter *iter,
                uint32_t enc_id,
                enum dpu_hw_blk_type type)
{
        memset(iter, 0, sizeof(*iter));
        iter->enc_id = enc_id;
        iter->type = type;
}

static bool _dpu_rm_get_hw_locked(struct dpu_rm *rm, struct dpu_rm_hw_iter *i)
{
        struct list_head *blk_list;

        if (!rm || !i || i->type >= DPU_HW_BLK_MAX) {
                DPU_ERROR("invalid rm\n");
                return false;
        }

        i->hw = NULL;
        blk_list = &rm->hw_blks[i->type];

        if (i->blk && (&i->blk->list == blk_list)) {
                DPU_DEBUG("attempt resume iteration past last\n");
                return false;
        }

        i->blk = list_prepare_entry(i->blk, blk_list, list);

        list_for_each_entry_continue(i->blk, blk_list, list) {
                if (i->enc_id == i->blk->enc_id) {
                        i->hw = i->blk->hw;
                        DPU_DEBUG("found type %d id %d for enc %d\n",
                                        i->type, i->blk->id, i->enc_id);
                        return true;
                }
        }

        DPU_DEBUG("no match, type %d for enc %d\n", i->type, i->enc_id);

        return false;
}

bool dpu_rm_get_hw(struct dpu_rm *rm, struct dpu_rm_hw_iter *i)
{
        bool ret;

        mutex_lock(&rm->rm_lock);
        ret = _dpu_rm_get_hw_locked(rm, i);
        mutex_unlock(&rm->rm_lock);

        return ret;
}

static void _dpu_rm_hw_destroy(enum dpu_hw_blk_type type, void *hw)
{
        switch (type) {
        case DPU_HW_BLK_LM:
                dpu_hw_lm_destroy(hw);
                break;
        case DPU_HW_BLK_CTL:
                dpu_hw_ctl_destroy(hw);
                break;
        case DPU_HW_BLK_PINGPONG:
                dpu_hw_pingpong_destroy(hw);
                break;
        case DPU_HW_BLK_INTF:
                dpu_hw_intf_destroy(hw);
                break;
        case DPU_HW_BLK_SSPP:
                /* SSPPs are not managed by the resource manager */
        case DPU_HW_BLK_TOP:
                /* Top is a singleton, not managed in hw_blks list */
        case DPU_HW_BLK_MAX:
        default:
                DPU_ERROR("unsupported block type %d\n", type);
                break;
        }
}

int dpu_rm_destroy(struct dpu_rm *rm)
{
        struct dpu_rm_hw_blk *hw_cur, *hw_nxt;
        enum dpu_hw_blk_type type;

        for (type = 0; type < DPU_HW_BLK_MAX; type++) {
                list_for_each_entry_safe(hw_cur, hw_nxt, &rm->hw_blks[type],
                                list) {
                        list_del(&hw_cur->list);
                        _dpu_rm_hw_destroy(type, hw_cur->hw);
                        kfree(hw_cur);
                }
        }

        mutex_destroy(&rm->rm_lock);

        return 0;
}

static int _dpu_rm_hw_blk_create(
                struct dpu_rm *rm,
                struct dpu_mdss_cfg *cat,
                void __iomem *mmio,
                enum dpu_hw_blk_type type,
                uint32_t id,
                void *hw_catalog_info)
{
        struct dpu_rm_hw_blk *blk;
        void *hw;

        switch (type) {
        case DPU_HW_BLK_LM:
                hw = dpu_hw_lm_init(id, mmio, cat);
                break;
        case DPU_HW_BLK_CTL:
                hw = dpu_hw_ctl_init(id, mmio, cat);
                break;
        case DPU_HW_BLK_PINGPONG:
                hw = dpu_hw_pingpong_init(id, mmio, cat);
                break;
        case DPU_HW_BLK_INTF:
                hw = dpu_hw_intf_init(id, mmio, cat);
                break;
        case DPU_HW_BLK_SSPP:
                /* SSPPs are not managed by the resource manager */
        case DPU_HW_BLK_TOP:
                /* Top is a singleton, not managed in hw_blks list */
        case DPU_HW_BLK_MAX:
        default:
                DPU_ERROR("unsupported block type %d\n", type);
                return -EINVAL;
        }

        if (IS_ERR_OR_NULL(hw)) {
                DPU_ERROR("failed hw object creation: type %d, err %ld\n",
                                type, PTR_ERR(hw));
                return -EFAULT;
        }

        blk = kzalloc(sizeof(*blk), GFP_KERNEL);
        if (!blk) {
                _dpu_rm_hw_destroy(type, hw);
                return -ENOMEM;
        }

        blk->id = id;
        blk->hw = hw;
        blk->enc_id = 0;
        list_add_tail(&blk->list, &rm->hw_blks[type]);

        return 0;
}

int dpu_rm_init(struct dpu_rm *rm,
                struct dpu_mdss_cfg *cat,
                void __iomem *mmio)
{
        int rc, i;
        enum dpu_hw_blk_type type;

        if (!rm || !cat || !mmio) {
                DPU_ERROR("invalid kms\n");
                return -EINVAL;
        }

        /* Clear, setup lists */
        memset(rm, 0, sizeof(*rm));

        mutex_init(&rm->rm_lock);

        for (type = 0; type < DPU_HW_BLK_MAX; type++)
                INIT_LIST_HEAD(&rm->hw_blks[type]);

        /* Interrogate HW catalog and create tracking items for hw blocks */
        for (i = 0; i < cat->mixer_count; i++) {
                struct dpu_lm_cfg *lm = &cat->mixer[i];

                if (lm->pingpong == PINGPONG_MAX) {
                        DPU_DEBUG("skip mixer %d without pingpong\n", lm->id);
                        continue;
                }

                rc = _dpu_rm_hw_blk_create(rm, cat, mmio, DPU_HW_BLK_LM,
                                cat->mixer[i].id, &cat->mixer[i]);
                if (rc) {
                        DPU_ERROR("failed: lm hw not available\n");
                        goto fail;
                }

                if (!rm->lm_max_width) {
                        rm->lm_max_width = lm->sblk->maxwidth;
                } else if (rm->lm_max_width != lm->sblk->maxwidth) {
                        /*
                         * Don't expect to have hw where lm max widths differ.
                         * If found, take the min.
                         */
                        DPU_ERROR("unsupported: lm maxwidth differs\n");
                        if (rm->lm_max_width > lm->sblk->maxwidth)
                                rm->lm_max_width = lm->sblk->maxwidth;
                }
        }

        for (i = 0; i < cat->pingpong_count; i++) {
                rc = _dpu_rm_hw_blk_create(rm, cat, mmio, DPU_HW_BLK_PINGPONG,
                                cat->pingpong[i].id, &cat->pingpong[i]);
                if (rc) {
                        DPU_ERROR("failed: pp hw not available\n");
                        goto fail;
                }
        }

        for (i = 0; i < cat->intf_count; i++) {
                if (cat->intf[i].type == INTF_NONE) {
                        DPU_DEBUG("skip intf %d with type none\n", i);
                        continue;
                }

                rc = _dpu_rm_hw_blk_create(rm, cat, mmio, DPU_HW_BLK_INTF,
                                cat->intf[i].id, &cat->intf[i]);
                if (rc) {
                        DPU_ERROR("failed: intf hw not available\n");
                        goto fail;
                }
        }

        for (i = 0; i < cat->ctl_count; i++) {
                rc = _dpu_rm_hw_blk_create(rm, cat, mmio, DPU_HW_BLK_CTL,
                                cat->ctl[i].id, &cat->ctl[i]);
                if (rc) {
                        DPU_ERROR("failed: ctl hw not available\n");
                        goto fail;
                }
        }

        return 0;

fail:
        dpu_rm_destroy(rm);

        return rc;
}

static bool _dpu_rm_needs_split_display(const struct msm_display_topology *top)
{
        return top->num_intf > 1;
}

/**
 * _dpu_rm_check_lm_and_get_connected_blks - check if proposed layer mixer meets
 *      proposed use case requirements, incl. hardwired dependent blocks like
 *      pingpong
 * @rm: dpu resource manager handle
 * @enc_id: encoder id requesting for allocation
 * @reqs: proposed use case requirements
 * @lm: proposed layer mixer, function checks if lm, and all other hardwired
 *      blocks connected to the lm (pp) is available and appropriate
 * @pp: output parameter, pingpong block attached to the layer mixer.
 *      NULL if pp was not available, or not matching requirements.
 * @primary_lm: if non-null, this function check if lm is compatible primary_lm
 *              as well as satisfying all other requirements
 * @Return: true if lm matches all requirements, false otherwise
 */
static bool _dpu_rm_check_lm_and_get_connected_blks(
                struct dpu_rm *rm,
                uint32_t enc_id,
                struct dpu_rm_requirements *reqs,
                struct dpu_rm_hw_blk *lm,
                struct dpu_rm_hw_blk **pp,
                struct dpu_rm_hw_blk *primary_lm)
{
        const struct dpu_lm_cfg *lm_cfg = to_dpu_hw_mixer(lm->hw)->cap;
        struct dpu_rm_hw_iter iter;

        *pp = NULL;

        DPU_DEBUG("check lm %d pp %d\n",
                           lm_cfg->id, lm_cfg->pingpong);

        /* Check if this layer mixer is a peer of the proposed primary LM */
        if (primary_lm) {
                const struct dpu_lm_cfg *prim_lm_cfg =
                                to_dpu_hw_mixer(primary_lm->hw)->cap;

                if (!test_bit(lm_cfg->id, &prim_lm_cfg->lm_pair_mask)) {
                        DPU_DEBUG("lm %d not peer of lm %d\n", lm_cfg->id,
                                        prim_lm_cfg->id);
                        return false;
                }
        }

        /* Already reserved? */
        if (RESERVED_BY_OTHER(lm, enc_id)) {
                DPU_DEBUG("lm %d already reserved\n", lm_cfg->id);
                return false;
        }

        dpu_rm_init_hw_iter(&iter, 0, DPU_HW_BLK_PINGPONG);
        while (_dpu_rm_get_hw_locked(rm, &iter)) {
                if (iter.blk->id == lm_cfg->pingpong) {
                        *pp = iter.blk;
                        break;
                }
        }

        if (!*pp) {
                DPU_ERROR("failed to get pp on lm %d\n", lm_cfg->pingpong);
                return false;
        }

        if (RESERVED_BY_OTHER(*pp, enc_id)) {
                DPU_DEBUG("lm %d pp %d already reserved\n", lm->id,
                                (*pp)->id);
                return false;
        }

        return true;
}

static int _dpu_rm_reserve_lms(struct dpu_rm *rm, uint32_t enc_id,
                               struct dpu_rm_requirements *reqs)

{
        struct dpu_rm_hw_blk *lm[MAX_BLOCKS];
        struct dpu_rm_hw_blk *pp[MAX_BLOCKS];
        struct dpu_rm_hw_iter iter_i, iter_j;
        int lm_count = 0;
        int i, rc = 0;

        if (!reqs->topology.num_lm) {
                DPU_ERROR("invalid number of lm: %d\n", reqs->topology.num_lm);
                return -EINVAL;
        }

        /* Find a primary mixer */
        dpu_rm_init_hw_iter(&iter_i, 0, DPU_HW_BLK_LM);
        while (lm_count != reqs->topology.num_lm &&
                        _dpu_rm_get_hw_locked(rm, &iter_i)) {
                memset(&lm, 0, sizeof(lm));
                memset(&pp, 0, sizeof(pp));

                lm_count = 0;
                lm[lm_count] = iter_i.blk;

                if (!_dpu_rm_check_lm_and_get_connected_blks(
                                rm, enc_id, reqs, lm[lm_count],
                                &pp[lm_count], NULL))
                        continue;

                ++lm_count;

                /* Valid primary mixer found, find matching peers */
                dpu_rm_init_hw_iter(&iter_j, 0, DPU_HW_BLK_LM);

                while (lm_count != reqs->topology.num_lm &&
                                _dpu_rm_get_hw_locked(rm, &iter_j)) {
                        if (iter_i.blk == iter_j.blk)
                                continue;

                        if (!_dpu_rm_check_lm_and_get_connected_blks(
                                        rm, enc_id, reqs, iter_j.blk,
                                        &pp[lm_count], iter_i.blk))
                                continue;

                        lm[lm_count] = iter_j.blk;
                        ++lm_count;
                }
        }

        if (lm_count != reqs->topology.num_lm) {
                DPU_DEBUG("unable to find appropriate mixers\n");
                return -ENAVAIL;
        }

        for (i = 0; i < ARRAY_SIZE(lm); i++) {
                if (!lm[i])
                        break;

                lm[i]->enc_id = enc_id;
                pp[i]->enc_id = enc_id;

                trace_dpu_rm_reserve_lms(lm[i]->id, enc_id, pp[i]->id);
        }

        return rc;
}

static int _dpu_rm_reserve_ctls(
                struct dpu_rm *rm,
                uint32_t enc_id,
                const struct msm_display_topology *top)
{
        struct dpu_rm_hw_blk *ctls[MAX_BLOCKS];
        struct dpu_rm_hw_iter iter;
        int i = 0, num_ctls = 0;
        bool needs_split_display = false;

        memset(&ctls, 0, sizeof(ctls));

        /* each hw_intf needs its own hw_ctrl to program its control path */
        num_ctls = top->num_intf;

        needs_split_display = _dpu_rm_needs_split_display(top);

        dpu_rm_init_hw_iter(&iter, 0, DPU_HW_BLK_CTL);
        while (_dpu_rm_get_hw_locked(rm, &iter)) {
                const struct dpu_hw_ctl *ctl = to_dpu_hw_ctl(iter.blk->hw);
                unsigned long features = ctl->caps->features;
                bool has_split_display;

                if (RESERVED_BY_OTHER(iter.blk, enc_id))
                        continue;

                has_split_display = BIT(DPU_CTL_SPLIT_DISPLAY) & features;

                DPU_DEBUG("ctl %d caps 0x%lX\n", iter.blk->id, features);

                if (needs_split_display != has_split_display)
                        continue;

                ctls[i] = iter.blk;
                DPU_DEBUG("ctl %d match\n", iter.blk->id);

                if (++i == num_ctls)
                        break;
        }

        if (i != num_ctls)
                return -ENAVAIL;

        for (i = 0; i < ARRAY_SIZE(ctls) && i < num_ctls; i++) {
                ctls[i]->enc_id = enc_id;
                trace_dpu_rm_reserve_ctls(ctls[i]->id, enc_id);
        }

        return 0;
}

static int _dpu_rm_reserve_intf(
                struct dpu_rm *rm,
                uint32_t enc_id,
                uint32_t id,
                enum dpu_hw_blk_type type)
{
        struct dpu_rm_hw_iter iter;
        int ret = 0;

        /* Find the block entry in the rm, and note the reservation */
        dpu_rm_init_hw_iter(&iter, 0, type);
        while (_dpu_rm_get_hw_locked(rm, &iter)) {
                if (iter.blk->id != id)
                        continue;

                if (RESERVED_BY_OTHER(iter.blk, enc_id)) {
                        DPU_ERROR("type %d id %d already reserved\n", type, id);
                        return -ENAVAIL;
                }

                iter.blk->enc_id = enc_id;
                trace_dpu_rm_reserve_intf(iter.blk->id, enc_id);
                break;
        }

        /* Shouldn't happen since intfs are fixed at probe */
        if (!iter.hw) {
                DPU_ERROR("couldn't find type %d id %d\n", type, id);
                return -EINVAL;
        }

        return ret;
}

static int _dpu_rm_reserve_intf_related_hw(
                struct dpu_rm *rm,
                uint32_t enc_id,
                struct dpu_encoder_hw_resources *hw_res)
{
        int i, ret = 0;
        u32 id;

        for (i = 0; i < ARRAY_SIZE(hw_res->intfs); i++) {
                if (hw_res->intfs[i] == INTF_MODE_NONE)
                        continue;
                id = i + INTF_0;
                ret = _dpu_rm_reserve_intf(rm, enc_id, id,
                                DPU_HW_BLK_INTF);
                if (ret)
                        return ret;
        }

        return ret;
}

static int _dpu_rm_make_reservation(
                struct dpu_rm *rm,
                struct drm_encoder *enc,
                struct drm_crtc_state *crtc_state,
                struct dpu_rm_requirements *reqs)
{
        int ret;

        ret = _dpu_rm_reserve_lms(rm, enc->base.id, reqs);
        if (ret) {
                DPU_ERROR("unable to find appropriate mixers\n");
                return ret;
        }

        ret = _dpu_rm_reserve_ctls(rm, enc->base.id, &reqs->topology);
        if (ret) {
                DPU_ERROR("unable to find appropriate CTL\n");
                return ret;
        }

        ret = _dpu_rm_reserve_intf_related_hw(rm, enc->base.id, &reqs->hw_res);
        if (ret)
                return ret;

        return ret;
}

static int _dpu_rm_populate_requirements(
                struct dpu_rm *rm,
                struct drm_encoder *enc,
                struct drm_crtc_state *crtc_state,
                struct dpu_rm_requirements *reqs,
                struct msm_display_topology req_topology)
{
        dpu_encoder_get_hw_resources(enc, &reqs->hw_res);

        reqs->topology = req_topology;

        DRM_DEBUG_KMS("num_lm: %d num_enc: %d num_intf: %d\n",
                      reqs->topology.num_lm, reqs->topology.num_enc,
                      reqs->topology.num_intf);

        return 0;
}

static void _dpu_rm_release_reservation(struct dpu_rm *rm, uint32_t enc_id)
{
        struct dpu_rm_hw_blk *blk;
        enum dpu_hw_blk_type type;

        for (type = 0; type < DPU_HW_BLK_MAX; type++) {
                list_for_each_entry(blk, &rm->hw_blks[type], list) {
                        if (blk->enc_id == enc_id) {
                                blk->enc_id = 0;
                                DPU_DEBUG("rel enc %d %d %d\n", enc_id,
                                          type, blk->id);
                        }
                }
        }
}

void dpu_rm_release(struct dpu_rm *rm, struct drm_encoder *enc)
{
        mutex_lock(&rm->rm_lock);

        _dpu_rm_release_reservation(rm, enc->base.id);

        mutex_unlock(&rm->rm_lock);
}

int dpu_rm_reserve(
                struct dpu_rm *rm,
                struct drm_encoder *enc,
                struct drm_crtc_state *crtc_state,
                struct msm_display_topology topology,
                bool test_only)
{
        struct dpu_rm_requirements reqs;
        int ret;

        /* Check if this is just a page-flip */
        if (!drm_atomic_crtc_needs_modeset(crtc_state))
                return 0;

        DRM_DEBUG_KMS("reserving hw for enc %d crtc %d test_only %d\n",
                      enc->base.id, crtc_state->crtc->base.id, test_only);

        mutex_lock(&rm->rm_lock);

        ret = _dpu_rm_populate_requirements(rm, enc, crtc_state, &reqs,
                                            topology);
        if (ret) {
                DPU_ERROR("failed to populate hw requirements\n");
                goto end;
        }

        ret = _dpu_rm_make_reservation(rm, enc, crtc_state, &reqs);
        if (ret) {
                DPU_ERROR("failed to reserve hw resources: %d\n", ret);
                _dpu_rm_release_reservation(rm, enc->base.id);
        } else if (test_only) {
                 /* test_only: test the reservation and then undo */
                DPU_DEBUG("test_only: discard test [enc: %d]\n",
                                enc->base.id);
                _dpu_rm_release_reservation(rm, enc->base.id);
        }

end:
        mutex_unlock(&rm->rm_lock);

        return ret;
}