/*
 * Copyright 2013 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
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
 *
 * Authors: Dave Airlie
 *          Alon Levy
 */

#include <linux/dma-buf-map.h>
#include <linux/io-mapping.h>

#include "qxl_drv.h"
#include "qxl_object.h"

static int __qxl_bo_pin(struct qxl_bo *bo);
static void __qxl_bo_unpin(struct qxl_bo *bo);

static void qxl_ttm_bo_destroy(struct ttm_buffer_object *tbo)
{
        struct qxl_bo *bo;
        struct qxl_device *qdev;

        bo = to_qxl_bo(tbo);
        qdev = to_qxl(bo->tbo.base.dev);

        qxl_surface_evict(qdev, bo, false);
        WARN_ON_ONCE(bo->map_count > 0);
        mutex_lock(&qdev->gem.mutex);
        list_del_init(&bo->list);
        mutex_unlock(&qdev->gem.mutex);
        drm_gem_object_release(&bo->tbo.base);
        kfree(bo);
}

bool qxl_ttm_bo_is_qxl_bo(struct ttm_buffer_object *bo)
{
        if (bo->destroy == &qxl_ttm_bo_destroy)
                return true;
        return false;
}

void qxl_ttm_placement_from_domain(struct qxl_bo *qbo, u32 domain)
{
        u32 c = 0;
        u32 pflag = 0;
        unsigned int i;

        if (qbo->tbo.base.size <= PAGE_SIZE)
                pflag |= TTM_PL_FLAG_TOPDOWN;

        qbo->placement.placement = qbo->placements;
        qbo->placement.busy_placement = qbo->placements;
        if (domain == QXL_GEM_DOMAIN_VRAM) {
                qbo->placements[c].mem_type = TTM_PL_VRAM;
                qbo->placements[c++].flags = pflag;
        }
        if (domain == QXL_GEM_DOMAIN_SURFACE) {
                qbo->placements[c].mem_type = TTM_PL_PRIV;
                qbo->placements[c++].flags = pflag;
                qbo->placements[c].mem_type = TTM_PL_VRAM;
                qbo->placements[c++].flags = pflag;
        }
        if (domain == QXL_GEM_DOMAIN_CPU) {
                qbo->placements[c].mem_type = TTM_PL_SYSTEM;
                qbo->placements[c++].flags = pflag;
        }
        if (!c) {
                qbo->placements[c].mem_type = TTM_PL_SYSTEM;
                qbo->placements[c++].flags = 0;
        }
        qbo->placement.num_placement = c;
        qbo->placement.num_busy_placement = c;
        for (i = 0; i < c; ++i) {
                qbo->placements[i].fpfn = 0;
                qbo->placements[i].lpfn = 0;
        }
}

static const struct drm_gem_object_funcs qxl_object_funcs = {
        .free = qxl_gem_object_free,
        .open = qxl_gem_object_open,
        .close = qxl_gem_object_close,
        .pin = qxl_gem_prime_pin,
        .unpin = qxl_gem_prime_unpin,
        .get_sg_table = qxl_gem_prime_get_sg_table,
        .vmap = qxl_gem_prime_vmap,
        .vunmap = qxl_gem_prime_vunmap,
        .mmap = drm_gem_ttm_mmap,
        .print_info = drm_gem_ttm_print_info,
};

int qxl_bo_create(struct qxl_device *qdev, unsigned long size,
                  bool kernel, bool pinned, u32 domain, u32 priority,
                  struct qxl_surface *surf,
                  struct qxl_bo **bo_ptr)
{
        struct ttm_operation_ctx ctx = { !kernel, false };
        struct qxl_bo *bo;
        enum ttm_bo_type type;
        int r;

        if (kernel)
                type = ttm_bo_type_kernel;
        else
                type = ttm_bo_type_device;
        *bo_ptr = NULL;
        bo = kzalloc(sizeof(struct qxl_bo), GFP_KERNEL);
        if (bo == NULL)
                return -ENOMEM;
        size = roundup(size, PAGE_SIZE);
        r = drm_gem_object_init(&qdev->ddev, &bo->tbo.base, size);
        if (unlikely(r)) {
                kfree(bo);
                return r;
        }
        bo->tbo.base.funcs = &qxl_object_funcs;
        bo->type = domain;
        bo->surface_id = 0;
        INIT_LIST_HEAD(&bo->list);

        if (surf)
                bo->surf = *surf;

        qxl_ttm_placement_from_domain(bo, domain);

        bo->tbo.priority = priority;
        r = ttm_bo_init_reserved(&qdev->mman.bdev, &bo->tbo, size, type,
                                 &bo->placement, 0, &ctx, NULL, NULL,
                                 &qxl_ttm_bo_destroy);
        if (unlikely(r != 0)) {
                if (r != -ERESTARTSYS)
                        dev_err(qdev->ddev.dev,
                                "object_init failed for (%lu, 0x%08X)\n",
                                size, domain);
                return r;
        }
        if (pinned)
                ttm_bo_pin(&bo->tbo);
        ttm_bo_unreserve(&bo->tbo);
        *bo_ptr = bo;
        return 0;
}

int qxl_bo_vmap_locked(struct qxl_bo *bo, struct dma_buf_map *map)
{
        int r;

        dma_resv_assert_held(bo->tbo.base.resv);

        if (bo->kptr) {
                bo->map_count++;
                goto out;
        }
        r = ttm_bo_vmap(&bo->tbo, &bo->map);
        if (r)
                return r;
        bo->map_count = 1;

        /* TODO: Remove kptr in favor of map everywhere. */
        if (bo->map.is_iomem)
                bo->kptr = (void *)bo->map.vaddr_iomem;
        else
                bo->kptr = bo->map.vaddr;

out:
        *map = bo->map;
        return 0;
}

int qxl_bo_vmap(struct qxl_bo *bo, struct dma_buf_map *map)
{
        int r;

        r = qxl_bo_reserve(bo);
        if (r)
                return r;

        r = __qxl_bo_pin(bo);
        if (r) {
                qxl_bo_unreserve(bo);
                return r;
        }

        r = qxl_bo_vmap_locked(bo, map);
        qxl_bo_unreserve(bo);
        return r;
}

void *qxl_bo_kmap_atomic_page(struct qxl_device *qdev,
                              struct qxl_bo *bo, int page_offset)
{
        unsigned long offset;
        void *rptr;
        int ret;
        struct io_mapping *map;
        struct dma_buf_map bo_map;

        if (bo->tbo.resource->mem_type == TTM_PL_VRAM)
                map = qdev->vram_mapping;
        else if (bo->tbo.resource->mem_type == TTM_PL_PRIV)
                map = qdev->surface_mapping;
        else
                goto fallback;

        offset = bo->tbo.resource->start << PAGE_SHIFT;
        return io_mapping_map_atomic_wc(map, offset + page_offset);
fallback:
        if (bo->kptr) {
                rptr = bo->kptr + (page_offset * PAGE_SIZE);
                return rptr;
        }

        ret = qxl_bo_vmap_locked(bo, &bo_map);
        if (ret)
                return NULL;
        rptr = bo_map.vaddr; /* TODO: Use mapping abstraction properly */

        rptr += page_offset * PAGE_SIZE;
        return rptr;
}

void qxl_bo_vunmap_locked(struct qxl_bo *bo)
{
        dma_resv_assert_held(bo->tbo.base.resv);

        if (bo->kptr == NULL)
                return;
        bo->map_count--;
        if (bo->map_count > 0)
                return;
        bo->kptr = NULL;
        ttm_bo_vunmap(&bo->tbo, &bo->map);
}

int qxl_bo_vunmap(struct qxl_bo *bo)
{
        int r;

        r = qxl_bo_reserve(bo);
        if (r)
                return r;

        qxl_bo_vunmap_locked(bo);
        __qxl_bo_unpin(bo);
        qxl_bo_unreserve(bo);
        return 0;
}

void qxl_bo_kunmap_atomic_page(struct qxl_device *qdev,
                               struct qxl_bo *bo, void *pmap)
{
        if ((bo->tbo.resource->mem_type != TTM_PL_VRAM) &&
            (bo->tbo.resource->mem_type != TTM_PL_PRIV))
                goto fallback;

        io_mapping_unmap_atomic(pmap);
        return;
 fallback:
        qxl_bo_vunmap_locked(bo);
}

void qxl_bo_unref(struct qxl_bo **bo)
{
        if ((*bo) == NULL)
                return;

        drm_gem_object_put(&(*bo)->tbo.base);
        *bo = NULL;
}

struct qxl_bo *qxl_bo_ref(struct qxl_bo *bo)
{
        drm_gem_object_get(&bo->tbo.base);
        return bo;
}

static int __qxl_bo_pin(struct qxl_bo *bo)
{
        struct ttm_operation_ctx ctx = { false, false };
        struct drm_device *ddev = bo->tbo.base.dev;
        int r;

        if (bo->tbo.pin_count) {
                ttm_bo_pin(&bo->tbo);
                return 0;
        }
        qxl_ttm_placement_from_domain(bo, bo->type);
        r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
        if (likely(r == 0))
                ttm_bo_pin(&bo->tbo);
        if (unlikely(r != 0))
                dev_err(ddev->dev, "%p pin failed\n", bo);
        return r;
}

static void __qxl_bo_unpin(struct qxl_bo *bo)
{
        ttm_bo_unpin(&bo->tbo);
}

/*
 * Reserve the BO before pinning the object.  If the BO was reserved
 * beforehand, use the internal version directly __qxl_bo_pin.
 *
 */
int qxl_bo_pin(struct qxl_bo *bo)
{
        int r;

        r = qxl_bo_reserve(bo);
        if (r)
                return r;

        r = __qxl_bo_pin(bo);
        qxl_bo_unreserve(bo);
        return r;
}

/*
 * Reserve the BO before pinning the object.  If the BO was reserved
 * beforehand, use the internal version directly __qxl_bo_unpin.
 *
 */
int qxl_bo_unpin(struct qxl_bo *bo)
{
        int r;

        r = qxl_bo_reserve(bo);
        if (r)
                return r;

        __qxl_bo_unpin(bo);
        qxl_bo_unreserve(bo);
        return 0;
}

void qxl_bo_force_delete(struct qxl_device *qdev)
{
        struct qxl_bo *bo, *n;

        if (list_empty(&qdev->gem.objects))
                return;
        dev_err(qdev->ddev.dev, "Userspace still has active objects !\n");
        list_for_each_entry_safe(bo, n, &qdev->gem.objects, list) {
                dev_err(qdev->ddev.dev, "%p %p %lu %lu force free\n",
                        &bo->tbo.base, bo, (unsigned long)bo->tbo.base.size,
                        *((unsigned long *)&bo->tbo.base.refcount));
                mutex_lock(&qdev->gem.mutex);
                list_del_init(&bo->list);
                mutex_unlock(&qdev->gem.mutex);
                /* this should unref the ttm bo */
                drm_gem_object_put(&bo->tbo.base);
        }
}

int qxl_bo_init(struct qxl_device *qdev)
{
        return qxl_ttm_init(qdev);
}

void qxl_bo_fini(struct qxl_device *qdev)
{
        qxl_ttm_fini(qdev);
}

int qxl_bo_check_id(struct qxl_device *qdev, struct qxl_bo *bo)
{
        int ret;

        if (bo->type == QXL_GEM_DOMAIN_SURFACE && bo->surface_id == 0) {
                /* allocate a surface id for this surface now */
                ret = qxl_surface_id_alloc(qdev, bo);
                if (ret)
                        return ret;

                ret = qxl_hw_surface_alloc(qdev, bo);
                if (ret)
                        return ret;
        }
        return 0;
}

int qxl_surf_evict(struct qxl_device *qdev)
{
        struct ttm_resource_manager *man;

        man = ttm_manager_type(&qdev->mman.bdev, TTM_PL_PRIV);
        return ttm_resource_manager_evict_all(&qdev->mman.bdev, man);
}

int qxl_vram_evict(struct qxl_device *qdev)
{
        struct ttm_resource_manager *man;

        man = ttm_manager_type(&qdev->mman.bdev, TTM_PL_VRAM);
        return ttm_resource_manager_evict_all(&qdev->mman.bdev, man);
}