/*
 * Copyright (c) 2014, The Linux Foundation. All rights reserved.
 * Copyright (C) 2013 Red Hat
 * Author: Rob Clark <robdclark@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License 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.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */


#include "mdp5_kms.h"
#include "mdp5_smp.h"


struct mdp5_smp {
        struct drm_device *dev;

        uint8_t reserved[MAX_CLIENTS]; /* fixed MMBs allocation per client */

        int blk_cnt;
        int blk_size;

        /* register cache */
        u32 alloc_w[22];
        u32 alloc_r[22];
        u32 pipe_reqprio_fifo_wm0[SSPP_MAX];
        u32 pipe_reqprio_fifo_wm1[SSPP_MAX];
        u32 pipe_reqprio_fifo_wm2[SSPP_MAX];
};

static inline
struct mdp5_kms *get_kms(struct mdp5_smp *smp)
{
        struct msm_drm_private *priv = smp->dev->dev_private;

        return to_mdp5_kms(to_mdp_kms(priv->kms));
}

static inline u32 pipe2client(enum mdp5_pipe pipe, int plane)
{
#define CID_UNUSED      0

        if (WARN_ON(plane >= pipe2nclients(pipe)))
                return CID_UNUSED;

        /*
         * Note on SMP clients:
         * For ViG pipes, fetch Y/Cr/Cb-components clients are always
         * consecutive, and in that order.
         *
         * e.g.:
         * if mdp5_cfg->smp.clients[SSPP_VIG0] = N,
         *      Y  plane's client ID is N
         *      Cr plane's client ID is N + 1
         *      Cb plane's client ID is N + 2
         */

        return mdp5_cfg->smp.clients[pipe] + plane;
}

/* allocate blocks for the specified request: */
static int smp_request_block(struct mdp5_smp *smp,
                struct mdp5_smp_state *state,
                u32 cid, int nblks)
{
        void *cs = state->client_state[cid];
        int i, avail, cnt = smp->blk_cnt;
        uint8_t reserved;

        /* we shouldn't be requesting blocks for an in-use client: */
        WARN_ON(bitmap_weight(cs, cnt) > 0);

        reserved = smp->reserved[cid];

        if (reserved) {
                nblks = max(0, nblks - reserved);
                DBG("%d MMBs allocated (%d reserved)", nblks, reserved);
        }

        avail = cnt - bitmap_weight(state->state, cnt);
        if (nblks > avail) {
                dev_err(smp->dev->dev, "out of blks (req=%d > avail=%d)\n",
                                nblks, avail);
                return -ENOSPC;
        }

        for (i = 0; i < nblks; i++) {
                int blk = find_first_zero_bit(state->state, cnt);
                set_bit(blk, cs);
                set_bit(blk, state->state);
        }

        return 0;
}

static void set_fifo_thresholds(struct mdp5_smp *smp,
                enum mdp5_pipe pipe, int nblks)
{
        u32 smp_entries_per_blk = smp->blk_size / (128 / BITS_PER_BYTE);
        u32 val;

        /* 1/4 of SMP pool that is being fetched */
        val = (nblks * smp_entries_per_blk) / 4;

        smp->pipe_reqprio_fifo_wm0[pipe] = val * 1;
        smp->pipe_reqprio_fifo_wm1[pipe] = val * 2;
        smp->pipe_reqprio_fifo_wm2[pipe] = val * 3;
}

/*
 * NOTE: looks like if horizontal decimation is used (if we supported that)
 * then the width used to calculate SMP block requirements is the post-
 * decimated width.  Ie. SMP buffering sits downstream of decimation (which
 * presumably happens during the dma from scanout buffer).
 */
uint32_t mdp5_smp_calculate(struct mdp5_smp *smp,
                const struct mdp_format *format,
                u32 width, bool hdecim)
{
        struct mdp5_kms *mdp5_kms = get_kms(smp);
        int rev = mdp5_cfg_get_hw_rev(mdp5_kms->cfg);
        int i, hsub, nplanes, nlines;
        u32 fmt = format->base.pixel_format;
        uint32_t blkcfg = 0;

        nplanes = drm_format_num_planes(fmt);
        hsub = drm_format_horz_chroma_subsampling(fmt);

        /* different if BWC (compressed framebuffer?) enabled: */
        nlines = 2;

        /* Newer MDPs have split/packing logic, which fetches sub-sampled
         * U and V components (splits them from Y if necessary) and packs
         * them together, writes to SMP using a single client.
         */
        if ((rev > 0) && (format->chroma_sample > CHROMA_FULL)) {
                fmt = DRM_FORMAT_NV24;
                nplanes = 2;

                /* if decimation is enabled, HW decimates less on the
                 * sub sampled chroma components
                 */
                if (hdecim && (hsub > 1))
                        hsub = 1;
        }

        for (i = 0; i < nplanes; i++) {
                int n, fetch_stride, cpp;

                cpp = drm_format_plane_cpp(fmt, i);
                fetch_stride = width * cpp / (i ? hsub : 1);

                n = DIV_ROUND_UP(fetch_stride * nlines, smp->blk_size);

                /* for hw rev v1.00 */
                if (rev == 0)
                        n = roundup_pow_of_two(n);

                blkcfg |= (n << (8 * i));
        }

        return blkcfg;
}

int mdp5_smp_assign(struct mdp5_smp *smp, struct mdp5_smp_state *state,
                enum mdp5_pipe pipe, uint32_t blkcfg)
{
        struct mdp5_kms *mdp5_kms = get_kms(smp);
        struct drm_device *dev = mdp5_kms->dev;
        int i, ret;

        for (i = 0; i < pipe2nclients(pipe); i++) {
                u32 cid = pipe2client(pipe, i);
                int n = blkcfg & 0xff;

                if (!n)
                        continue;

                DBG("%s[%d]: request %d SMP blocks", pipe2name(pipe), i, n);
                ret = smp_request_block(smp, state, cid, n);
                if (ret) {
                        dev_err(dev->dev, "Cannot allocate %d SMP blocks: %d\n",
                                        n, ret);
                        return ret;
                }

                blkcfg >>= 8;
        }

        state->assigned |= (1 << pipe);

        return 0;
}

/* Release SMP blocks for all clients of the pipe */
void mdp5_smp_release(struct mdp5_smp *smp, struct mdp5_smp_state *state,
                enum mdp5_pipe pipe)
{
        int i;
        int cnt = smp->blk_cnt;

        for (i = 0; i < pipe2nclients(pipe); i++) {
                u32 cid = pipe2client(pipe, i);
                void *cs = state->client_state[cid];

                /* update global state: */
                bitmap_andnot(state->state, state->state, cs, cnt);

                /* clear client's state */
                bitmap_zero(cs, cnt);
        }

        state->released |= (1 << pipe);
}

/* NOTE: SMP_ALLOC_* regs are *not* double buffered, so release has to
 * happen after scanout completes.
 */
static unsigned update_smp_state(struct mdp5_smp *smp,
                u32 cid, mdp5_smp_state_t *assigned)
{
        int cnt = smp->blk_cnt;
        unsigned nblks = 0;
        u32 blk, val;

        for_each_set_bit(blk, *assigned, cnt) {
                int idx = blk / 3;
                int fld = blk % 3;

                val = smp->alloc_w[idx];

                switch (fld) {
                case 0:
                        val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT0__MASK;
                        val |= MDP5_SMP_ALLOC_W_REG_CLIENT0(cid);
                        break;
                case 1:
                        val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT1__MASK;
                        val |= MDP5_SMP_ALLOC_W_REG_CLIENT1(cid);
                        break;
                case 2:
                        val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT2__MASK;
                        val |= MDP5_SMP_ALLOC_W_REG_CLIENT2(cid);
                        break;
                }

                smp->alloc_w[idx] = val;
                smp->alloc_r[idx] = val;

                nblks++;
        }

        return nblks;
}

static void write_smp_alloc_regs(struct mdp5_smp *smp)
{
        struct mdp5_kms *mdp5_kms = get_kms(smp);
        int i, num_regs;

        num_regs = smp->blk_cnt / 3 + 1;

        for (i = 0; i < num_regs; i++) {
                mdp5_write(mdp5_kms, REG_MDP5_SMP_ALLOC_W_REG(i),
                           smp->alloc_w[i]);
                mdp5_write(mdp5_kms, REG_MDP5_SMP_ALLOC_R_REG(i),
                           smp->alloc_r[i]);
        }
}

static void write_smp_fifo_regs(struct mdp5_smp *smp)
{
        struct mdp5_kms *mdp5_kms = get_kms(smp);
        int i;

        for (i = 0; i < mdp5_kms->num_hwpipes; i++) {
                struct mdp5_hw_pipe *hwpipe = mdp5_kms->hwpipes[i];
                enum mdp5_pipe pipe = hwpipe->pipe;

                mdp5_write(mdp5_kms, REG_MDP5_PIPE_REQPRIO_FIFO_WM_0(pipe),
                           smp->pipe_reqprio_fifo_wm0[pipe]);
                mdp5_write(mdp5_kms, REG_MDP5_PIPE_REQPRIO_FIFO_WM_1(pipe),
                           smp->pipe_reqprio_fifo_wm1[pipe]);
                mdp5_write(mdp5_kms, REG_MDP5_PIPE_REQPRIO_FIFO_WM_2(pipe),
                           smp->pipe_reqprio_fifo_wm2[pipe]);
        }
}

void mdp5_smp_prepare_commit(struct mdp5_smp *smp, struct mdp5_smp_state *state)
{
        enum mdp5_pipe pipe;

        for_each_set_bit(pipe, &state->assigned, sizeof(state->assigned) * 8) {
                unsigned i, nblks = 0;

                for (i = 0; i < pipe2nclients(pipe); i++) {
                        u32 cid = pipe2client(pipe, i);
                        void *cs = state->client_state[cid];

                        nblks += update_smp_state(smp, cid, cs);

                        DBG("assign %s:%u, %u blks",
                                pipe2name(pipe), i, nblks);
                }

                set_fifo_thresholds(smp, pipe, nblks);
        }

        write_smp_alloc_regs(smp);
        write_smp_fifo_regs(smp);

        state->assigned = 0;
}

void mdp5_smp_complete_commit(struct mdp5_smp *smp, struct mdp5_smp_state *state)
{
        enum mdp5_pipe pipe;

        for_each_set_bit(pipe, &state->released, sizeof(state->released) * 8) {
                DBG("release %s", pipe2name(pipe));
                set_fifo_thresholds(smp, pipe, 0);
        }

        write_smp_fifo_regs(smp);

        state->released = 0;
}

void mdp5_smp_dump(struct mdp5_smp *smp, struct drm_printer *p)
{
        struct mdp5_kms *mdp5_kms = get_kms(smp);
        struct mdp5_hw_pipe_state *hwpstate;
        struct mdp5_smp_state *state;
        struct mdp5_global_state *global_state;
        int total = 0, i, j;

        drm_printf(p, "name\tinuse\tplane\n");
        drm_printf(p, "----\t-----\t-----\n");

        if (drm_can_sleep())
                drm_modeset_lock(&mdp5_kms->glob_state_lock, NULL);

        global_state = mdp5_get_existing_global_state(mdp5_kms);

        /* grab these *after* we hold the state_lock */
        hwpstate = &global_state->hwpipe;
        state = &global_state->smp;

        for (i = 0; i < mdp5_kms->num_hwpipes; i++) {
                struct mdp5_hw_pipe *hwpipe = mdp5_kms->hwpipes[i];
                struct drm_plane *plane = hwpstate->hwpipe_to_plane[hwpipe->idx];
                enum mdp5_pipe pipe = hwpipe->pipe;
                for (j = 0; j < pipe2nclients(pipe); j++) {
                        u32 cid = pipe2client(pipe, j);
                        void *cs = state->client_state[cid];
                        int inuse = bitmap_weight(cs, smp->blk_cnt);

                        drm_printf(p, "%s:%d\t%d\t%s\n",
                                pipe2name(pipe), j, inuse,
                                plane ? plane->name : NULL);

                        total += inuse;
                }
        }

        drm_printf(p, "TOTAL:\t%d\t(of %d)\n", total, smp->blk_cnt);
        drm_printf(p, "AVAIL:\t%d\n", smp->blk_cnt -
                        bitmap_weight(state->state, smp->blk_cnt));

        if (drm_can_sleep())
                drm_modeset_unlock(&mdp5_kms->glob_state_lock);
}

void mdp5_smp_destroy(struct mdp5_smp *smp)
{
        kfree(smp);
}

struct mdp5_smp *mdp5_smp_init(struct mdp5_kms *mdp5_kms, const struct mdp5_smp_block *cfg)
{
        struct mdp5_smp_state *state;
        struct mdp5_global_state *global_state;
        struct mdp5_smp *smp = NULL;
        int ret;

        smp = kzalloc(sizeof(*smp), GFP_KERNEL);
        if (unlikely(!smp)) {
                ret = -ENOMEM;
                goto fail;
        }

        smp->dev = mdp5_kms->dev;
        smp->blk_cnt = cfg->mmb_count;
        smp->blk_size = cfg->mmb_size;

        global_state = mdp5_get_existing_global_state(mdp5_kms);
        state = &global_state->smp;

        /* statically tied MMBs cannot be re-allocated: */
        bitmap_copy(state->state, cfg->reserved_state, smp->blk_cnt);
        memcpy(smp->reserved, cfg->reserved, sizeof(smp->reserved));

        return smp;
fail:
        if (smp)
                mdp5_smp_destroy(smp);

        return ERR_PTR(ret);
}