/*
 * Copyright 2011 Red Hat, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, and/or sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#include "qxl_drv.h"
#include "qxl_object.h"
#include <trace/events/fence.h>

/*
 * drawable cmd cache - allocate a bunch of VRAM pages, suballocate
 * into 256 byte chunks for now - gives 16 cmds per page.
 *
 * use an ida to index into the chunks?
 */
/* manage releaseables */
/* stack them 16 high for now -drawable object is 191 */
#define RELEASE_SIZE 256
#define RELEASES_PER_BO (4096 / RELEASE_SIZE)
/* put an alloc/dealloc surface cmd into one bo and round up to 128 */
#define SURFACE_RELEASE_SIZE 128
#define SURFACE_RELEASES_PER_BO (4096 / SURFACE_RELEASE_SIZE)

static const int release_size_per_bo[] = { RELEASE_SIZE, SURFACE_RELEASE_SIZE, RELEASE_SIZE };
static const int releases_per_bo[] = { RELEASES_PER_BO, SURFACE_RELEASES_PER_BO, RELEASES_PER_BO };

static const char *qxl_get_driver_name(struct fence *fence)
{
        return "qxl";
}

static const char *qxl_get_timeline_name(struct fence *fence)
{
        return "release";
}

static bool qxl_nop_signaling(struct fence *fence)
{
        /* fences are always automatically signaled, so just pretend we did this.. */
        return true;
}

static long qxl_fence_wait(struct fence *fence, bool intr, signed long timeout)
{
        struct qxl_device *qdev;
        struct qxl_release *release;
        int count = 0, sc = 0;
        bool have_drawable_releases;
        unsigned long cur, end = jiffies + timeout;

        qdev = container_of(fence->lock, struct qxl_device, release_lock);
        release = container_of(fence, struct qxl_release, base);
        have_drawable_releases = release->type == QXL_RELEASE_DRAWABLE;

retry:
        sc++;

        if (fence_is_signaled(fence))
                goto signaled;

        qxl_io_notify_oom(qdev);

        for (count = 0; count < 11; count++) {
                if (!qxl_queue_garbage_collect(qdev, true))
                        break;

                if (fence_is_signaled(fence))
                        goto signaled;
        }

        if (fence_is_signaled(fence))
                goto signaled;

        if (have_drawable_releases || sc < 4) {
                if (sc > 2)
                        /* back off */
                        usleep_range(500, 1000);

                if (time_after(jiffies, end))
                        return 0;

                if (have_drawable_releases && sc > 300) {
                        FENCE_WARN(fence, "failed to wait on release %d "
                                          "after spincount %d\n",
                                          fence->context & ~0xf0000000, sc);
                        goto signaled;
                }
                goto retry;
        }
        /*
         * yeah, original sync_obj_wait gave up after 3 spins when
         * have_drawable_releases is not set.
         */

signaled:
        cur = jiffies;
        if (time_after(cur, end))
                return 0;
        return end - cur;
}

static const struct fence_ops qxl_fence_ops = {
        .get_driver_name = qxl_get_driver_name,
        .get_timeline_name = qxl_get_timeline_name,
        .enable_signaling = qxl_nop_signaling,
        .wait = qxl_fence_wait,
};

static uint64_t
qxl_release_alloc(struct qxl_device *qdev, int type,
                  struct qxl_release **ret)
{
        struct qxl_release *release;
        int handle;
        size_t size = sizeof(*release);

        release = kmalloc(size, GFP_KERNEL);
        if (!release) {
                DRM_ERROR("Out of memory\n");
                return 0;
        }
        release->base.ops = NULL;
        release->type = type;
        release->release_offset = 0;
        release->surface_release_id = 0;
        INIT_LIST_HEAD(&release->bos);

        idr_preload(GFP_KERNEL);
        spin_lock(&qdev->release_idr_lock);
        handle = idr_alloc(&qdev->release_idr, release, 1, 0, GFP_NOWAIT);
        release->base.seqno = ++qdev->release_seqno;
        spin_unlock(&qdev->release_idr_lock);
        idr_preload_end();
        if (handle < 0) {
                kfree(release);
                *ret = NULL;
                return handle;
        }
        *ret = release;
        QXL_INFO(qdev, "allocated release %lld\n", handle);
        release->id = handle;
        return handle;
}

static void
qxl_release_free_list(struct qxl_release *release)
{
        while (!list_empty(&release->bos)) {
                struct qxl_bo_list *entry;
                struct qxl_bo *bo;

                entry = container_of(release->bos.next,
                                     struct qxl_bo_list, tv.head);
                bo = to_qxl_bo(entry->tv.bo);
                qxl_bo_unref(&bo);
                list_del(&entry->tv.head);
                kfree(entry);
        }
}

void
qxl_release_free(struct qxl_device *qdev,
                 struct qxl_release *release)
{
        QXL_INFO(qdev, "release %d, type %d\n", release->id,
                 release->type);

        if (release->surface_release_id)
                qxl_surface_id_dealloc(qdev, release->surface_release_id);

        spin_lock(&qdev->release_idr_lock);
        idr_remove(&qdev->release_idr, release->id);
        spin_unlock(&qdev->release_idr_lock);

        if (release->base.ops) {
                WARN_ON(list_empty(&release->bos));
                qxl_release_free_list(release);

                fence_signal(&release->base);
                fence_put(&release->base);
        } else {
                qxl_release_free_list(release);
                kfree(release);
        }
}

static int qxl_release_bo_alloc(struct qxl_device *qdev,
                                struct qxl_bo **bo)
{
        int ret;
        /* pin releases bo's they are too messy to evict */
        ret = qxl_bo_create(qdev, PAGE_SIZE, false, true,
                            QXL_GEM_DOMAIN_VRAM, NULL,
                            bo);
        return ret;
}

int qxl_release_list_add(struct qxl_release *release, struct qxl_bo *bo)
{
        struct qxl_bo_list *entry;

        list_for_each_entry(entry, &release->bos, tv.head) {
                if (entry->tv.bo == &bo->tbo)
                        return 0;
        }

        entry = kmalloc(sizeof(struct qxl_bo_list), GFP_KERNEL);
        if (!entry)
                return -ENOMEM;

        qxl_bo_ref(bo);
        entry->tv.bo = &bo->tbo;
        entry->tv.shared = false;
        list_add_tail(&entry->tv.head, &release->bos);
        return 0;
}

static int qxl_release_validate_bo(struct qxl_bo *bo)
{
        int ret;

        if (!bo->pin_count) {
                qxl_ttm_placement_from_domain(bo, bo->type, false);
                ret = ttm_bo_validate(&bo->tbo, &bo->placement,
                                      true, false);
                if (ret)
                        return ret;
        }

        ret = reservation_object_reserve_shared(bo->tbo.resv);
        if (ret)
                return ret;

        /* allocate a surface for reserved + validated buffers */
        ret = qxl_bo_check_id(bo->gem_base.dev->dev_private, bo);
        if (ret)
                return ret;
        return 0;
}

int qxl_release_reserve_list(struct qxl_release *release, bool no_intr)
{
        int ret;
        struct qxl_bo_list *entry;

        /* if only one object on the release its the release itself
           since these objects are pinned no need to reserve */
        if (list_is_singular(&release->bos))
                return 0;

        ret = ttm_eu_reserve_buffers(&release->ticket, &release->bos,
                                     !no_intr, NULL);
        if (ret)
                return ret;

        list_for_each_entry(entry, &release->bos, tv.head) {
                struct qxl_bo *bo = to_qxl_bo(entry->tv.bo);

                ret = qxl_release_validate_bo(bo);
                if (ret) {
                        ttm_eu_backoff_reservation(&release->ticket, &release->bos);
                        return ret;
                }
        }
        return 0;
}

void qxl_release_backoff_reserve_list(struct qxl_release *release)
{
        /* if only one object on the release its the release itself
           since these objects are pinned no need to reserve */
        if (list_is_singular(&release->bos))
                return;

        ttm_eu_backoff_reservation(&release->ticket, &release->bos);
}


int qxl_alloc_surface_release_reserved(struct qxl_device *qdev,
                                       enum qxl_surface_cmd_type surface_cmd_type,
                                       struct qxl_release *create_rel,
                                       struct qxl_release **release)
{
        if (surface_cmd_type == QXL_SURFACE_CMD_DESTROY && create_rel) {
                int idr_ret;
                struct qxl_bo_list *entry = list_first_entry(&create_rel->bos, struct qxl_bo_list, tv.head);
                struct qxl_bo *bo;
                union qxl_release_info *info;

                /* stash the release after the create command */
                idr_ret = qxl_release_alloc(qdev, QXL_RELEASE_SURFACE_CMD, release);
                if (idr_ret < 0)
                        return idr_ret;
                bo = qxl_bo_ref(to_qxl_bo(entry->tv.bo));

                (*release)->release_offset = create_rel->release_offset + 64;

                qxl_release_list_add(*release, bo);

                info = qxl_release_map(qdev, *release);
                info->id = idr_ret;
                qxl_release_unmap(qdev, *release, info);

                qxl_bo_unref(&bo);
                return 0;
        }

        return qxl_alloc_release_reserved(qdev, sizeof(struct qxl_surface_cmd),
                                         QXL_RELEASE_SURFACE_CMD, release, NULL);
}

int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
                                       int type, struct qxl_release **release,
                                       struct qxl_bo **rbo)
{
        struct qxl_bo *bo;
        int idr_ret;
        int ret = 0;
        union qxl_release_info *info;
        int cur_idx;

        if (type == QXL_RELEASE_DRAWABLE)
                cur_idx = 0;
        else if (type == QXL_RELEASE_SURFACE_CMD)
                cur_idx = 1;
        else if (type == QXL_RELEASE_CURSOR_CMD)
                cur_idx = 2;
        else {
                DRM_ERROR("got illegal type: %d\n", type);
                return -EINVAL;
        }

        idr_ret = qxl_release_alloc(qdev, type, release);
        if (idr_ret < 0) {
                if (rbo)
                        *rbo = NULL;
                return idr_ret;
        }

        mutex_lock(&qdev->release_mutex);
        if (qdev->current_release_bo_offset[cur_idx] + 1 >= releases_per_bo[cur_idx]) {
                qxl_bo_unref(&qdev->current_release_bo[cur_idx]);
                qdev->current_release_bo_offset[cur_idx] = 0;
                qdev->current_release_bo[cur_idx] = NULL;
        }
        if (!qdev->current_release_bo[cur_idx]) {
                ret = qxl_release_bo_alloc(qdev, &qdev->current_release_bo[cur_idx]);
                if (ret) {
                        mutex_unlock(&qdev->release_mutex);
                        return ret;
                }
        }

        bo = qxl_bo_ref(qdev->current_release_bo[cur_idx]);

        (*release)->release_offset = qdev->current_release_bo_offset[cur_idx] * release_size_per_bo[cur_idx];
        qdev->current_release_bo_offset[cur_idx]++;

        if (rbo)
                *rbo = bo;

        mutex_unlock(&qdev->release_mutex);

        qxl_release_list_add(*release, bo);

        info = qxl_release_map(qdev, *release);
        info->id = idr_ret;
        qxl_release_unmap(qdev, *release, info);

        qxl_bo_unref(&bo);
        return ret;
}

struct qxl_release *qxl_release_from_id_locked(struct qxl_device *qdev,
                                                   uint64_t id)
{
        struct qxl_release *release;

        spin_lock(&qdev->release_idr_lock);
        release = idr_find(&qdev->release_idr, id);
        spin_unlock(&qdev->release_idr_lock);
        if (!release) {
                DRM_ERROR("failed to find id in release_idr\n");
                return NULL;
        }

        return release;
}

union qxl_release_info *qxl_release_map(struct qxl_device *qdev,
                                        struct qxl_release *release)
{
        void *ptr;
        union qxl_release_info *info;
        struct qxl_bo_list *entry = list_first_entry(&release->bos, struct qxl_bo_list, tv.head);
        struct qxl_bo *bo = to_qxl_bo(entry->tv.bo);

        ptr = qxl_bo_kmap_atomic_page(qdev, bo, release->release_offset & PAGE_SIZE);
        if (!ptr)
                return NULL;
        info = ptr + (release->release_offset & ~PAGE_SIZE);
        return info;
}

void qxl_release_unmap(struct qxl_device *qdev,
                       struct qxl_release *release,
                       union qxl_release_info *info)
{
        struct qxl_bo_list *entry = list_first_entry(&release->bos, struct qxl_bo_list, tv.head);
        struct qxl_bo *bo = to_qxl_bo(entry->tv.bo);
        void *ptr;

        ptr = ((void *)info) - (release->release_offset & ~PAGE_SIZE);
        qxl_bo_kunmap_atomic_page(qdev, bo, ptr);
}

void qxl_release_fence_buffer_objects(struct qxl_release *release)
{
        struct ttm_buffer_object *bo;
        struct ttm_bo_global *glob;
        struct ttm_bo_device *bdev;
        struct ttm_bo_driver *driver;
        struct qxl_bo *qbo;
        struct ttm_validate_buffer *entry;
        struct qxl_device *qdev;

        /* if only one object on the release its the release itself
           since these objects are pinned no need to reserve */
        if (list_is_singular(&release->bos) || list_empty(&release->bos))
                return;

        bo = list_first_entry(&release->bos, struct ttm_validate_buffer, head)->bo;
        bdev = bo->bdev;
        qdev = container_of(bdev, struct qxl_device, mman.bdev);

        /*
         * Since we never really allocated a context and we don't want to conflict,
         * set the highest bits. This will break if we really allow exporting of dma-bufs.
         */
        fence_init(&release->base, &qxl_fence_ops, &qdev->release_lock,
                   release->id | 0xf0000000, release->base.seqno);
        trace_fence_emit(&release->base);

        driver = bdev->driver;
        glob = bo->glob;

        spin_lock(&glob->lru_lock);

        list_for_each_entry(entry, &release->bos, head) {
                bo = entry->bo;
                qbo = to_qxl_bo(bo);

                reservation_object_add_shared_fence(bo->resv, &release->base);
                ttm_bo_add_to_lru(bo);
                __ttm_bo_unreserve(bo);
        }
        spin_unlock(&glob->lru_lock);
        ww_acquire_fini(&release->ticket);
}