/*
 * 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 <linux/delay.h>

#include <drm/drm_print.h>

#include <trace/events/dma_fence.h>

#include "qxl_drv.h"
#include "qxl_object.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 (PAGE_SIZE / 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 (PAGE_SIZE / 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 dma_fence *fence)
{
        return "qxl";
}

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

static long qxl_fence_wait(struct dma_fence *fence, bool intr,
                           signed long timeout)
{
        struct qxl_device *qdev;
        unsigned long cur, end = jiffies + timeout;

        qdev = container_of(fence->lock, struct qxl_device, release_lock);

        if (!wait_event_timeout(qdev->release_event,
                                (dma_fence_is_signaled(fence) ||
                                 (qxl_io_notify_oom(qdev), 0)),
                                timeout))
                return 0;

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

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

static int
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 -ENOMEM;
        }
        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;
        DRM_DEBUG_DRIVER("allocated release %d\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;

                entry = container_of(release->bos.next,
                                     struct qxl_bo_list, list);
                qxl_bo_unref(&entry->bo);
                list_del(&entry->list);
                kfree(entry);
        }
        release->release_bo = NULL;
}

void
qxl_release_free(struct qxl_device *qdev,
                 struct qxl_release *release)
{
        DRM_DEBUG_DRIVER("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);

                dma_fence_signal(&release->base);
                dma_fence_put(&release->base);
        } else {
                qxl_release_free_list(release);
                kfree(release);
        }
        atomic_dec(&qdev->release_count);
}

static int qxl_release_bo_alloc(struct qxl_device *qdev,
                                struct qxl_bo **bo,
                                u32 priority)
{
        /* pin releases bo's they are too messy to evict */
        return qxl_bo_create(qdev, PAGE_SIZE, false, true,
                             QXL_GEM_DOMAIN_VRAM, priority, NULL, bo);
}

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, list) {
                if (entry->bo == bo)
                        return 0;
        }

        entry = kmalloc_obj(struct qxl_bo_list);
        if (!entry)
                return -ENOMEM;

        qxl_bo_ref(bo);
        entry->bo = bo;
        list_add_tail(&entry->list, &release->bos);
        return 0;
}

static int qxl_release_validate_bo(struct qxl_bo *bo)
{
        struct ttm_operation_ctx ctx = { true, false };
        int ret;

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

        ret = dma_resv_reserve_fences(bo->tbo.base.resv, 1);
        if (ret)
                return ret;

        /* allocate a surface for reserved + validated buffers */
        ret = qxl_bo_check_id(to_qxl(bo->tbo.base.dev), 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;

        drm_exec_init(&release->exec, no_intr ? 0 :
                      DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
        drm_exec_until_all_locked(&release->exec) {
                list_for_each_entry(entry, &release->bos, list) {
                        ret = drm_exec_prepare_obj(&release->exec,
                                                   &entry->bo->tbo.base,
                                                   1);
                        drm_exec_retry_on_contention(&release->exec);
                        if (ret)
                                goto error;
                }
        }

        list_for_each_entry(entry, &release->bos, list) {
                ret = qxl_release_validate_bo(entry->bo);
                if (ret)
                        goto error;
        }
        return 0;
error:
        drm_exec_fini(&release->exec);
        return ret;
}

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;

        drm_exec_fini(&release->exec);
}

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 *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 = create_rel->release_bo;

                (*release)->release_bo = 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);
                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, *free_bo = NULL;
        int idr_ret;
        int ret = 0;
        union qxl_release_info *info;
        int cur_idx;
        u32 priority;

        if (type == QXL_RELEASE_DRAWABLE) {
                cur_idx = 0;
                priority = 0;
        } else if (type == QXL_RELEASE_SURFACE_CMD) {
                cur_idx = 1;
                priority = 1;
        } else if (type == QXL_RELEASE_CURSOR_CMD) {
                cur_idx = 2;
                priority = 1;
        }
        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;
        }
        atomic_inc(&qdev->release_count);

        mutex_lock(&qdev->release_mutex);
        if (qdev->current_release_bo_offset[cur_idx] + 1 >= releases_per_bo[cur_idx]) {
                free_bo = 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], priority);
                if (ret) {
                        mutex_unlock(&qdev->release_mutex);
                        if (free_bo) {
                                qxl_bo_unpin(free_bo);
                                qxl_bo_unref(&free_bo);
                        }
                        qxl_release_free(qdev, *release);
                        return ret;
                }
        }

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

        (*release)->release_bo = bo;
        (*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);
        if (free_bo) {
                qxl_bo_unpin(free_bo);
                qxl_bo_unref(&free_bo);
        }

        ret = qxl_release_list_add(*release, bo);
        qxl_bo_unref(&bo);
        if (ret) {
                qxl_release_free(qdev, *release);
                return ret;
        }

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

        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 *bo = release->release_bo;

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

void qxl_release_unmap(struct qxl_device *qdev,
                       struct qxl_release *release,
                       union qxl_release_info *info)
{
        struct qxl_bo *bo = release->release_bo;
        void *ptr;

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

void qxl_release_fence_buffer_objects(struct qxl_release *release)
{
        struct ttm_device *bdev;
        struct qxl_bo_list *entry;
        struct qxl_device *qdev;
        struct qxl_bo *bo;

        /* 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 qxl_bo_list, list)->bo;
        bdev = bo->tbo.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.
         */
        dma_fence_init(&release->base, &qxl_fence_ops, &qdev->release_lock,
                       release->id | 0xf0000000, release->base.seqno);
        trace_dma_fence_emit(&release->base);

        list_for_each_entry(entry, &release->bos, list) {
                bo = entry->bo;

                dma_resv_add_fence(bo->tbo.base.resv, &release->base,
                                   DMA_RESV_USAGE_READ);
                ttm_bo_move_to_lru_tail_unlocked(&bo->tbo);
        }
        drm_exec_fini(&release->exec);
}