/*
 * 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);
}