/*
 * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
 * Author:Mark Yao <mark.yao@rock-chips.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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.
 */

#include <drm/drm.h>
#include <drm/drmP.h>
#include <drm/drm_gem.h>
#include <drm/drm_vma_manager.h>

#include <linux/dma-attrs.h>

#include "rockchip_drm_drv.h"
#include "rockchip_drm_gem.h"

static int rockchip_gem_alloc_buf(struct rockchip_gem_object *rk_obj)
{
	struct drm_gem_object *obj = &rk_obj->base;
	struct drm_device *drm = obj->dev;

	init_dma_attrs(&rk_obj->dma_attrs);
	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &rk_obj->dma_attrs);

	/* TODO(djkurtz): Use DMA_ATTR_NO_KERNEL_MAPPING except for fbdev */
	rk_obj->kvaddr = dma_alloc_attrs(drm->dev, obj->size,
					 &rk_obj->dma_addr, GFP_KERNEL,
					 &rk_obj->dma_attrs);
	if (IS_ERR(rk_obj->kvaddr)) {
		int ret = PTR_ERR(rk_obj->kvaddr);

		DRM_ERROR("failed to allocate %#x byte dma buffer, %d",
			  obj->size, ret);
		return ret;
	}

	return 0;
}

static void rockchip_gem_free_buf(struct rockchip_gem_object *rk_obj)
{
	struct drm_gem_object *obj = &rk_obj->base;
	struct drm_device *drm = obj->dev;

	dma_free_attrs(drm->dev, obj->size, rk_obj->kvaddr, rk_obj->dma_addr,
		       &rk_obj->dma_attrs);
}

int rockchip_gem_mmap_buf(struct drm_gem_object *obj,
			  struct vm_area_struct *vma)
{
	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
	struct drm_device *drm = obj->dev;
	unsigned long vm_size;

	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
	vm_size = vma->vm_end - vma->vm_start;

	if (vm_size > obj->size)
		return -EINVAL;

	return dma_mmap_attrs(drm->dev, vma, rk_obj->kvaddr, rk_obj->dma_addr,
			     obj->size, &rk_obj->dma_attrs);
}

/* drm driver mmap file operations */
int rockchip_gem_mmap(struct file *filp, struct vm_area_struct *vma)
{
	struct drm_file *priv = filp->private_data;
	struct drm_device *dev = priv->minor->dev;
	struct drm_gem_object *obj;
	struct drm_vma_offset_node *node;
	int ret;

	if (drm_device_is_unplugged(dev))
		return -ENODEV;

	mutex_lock(&dev->struct_mutex);

	node = drm_vma_offset_exact_lookup(dev->vma_offset_manager,
					   vma->vm_pgoff,
					   vma_pages(vma));
	if (!node) {
		mutex_unlock(&dev->struct_mutex);
		DRM_ERROR("failed to find vma node.\n");
		return -EINVAL;
	} else if (!drm_vma_node_is_allowed(node, filp)) {
		mutex_unlock(&dev->struct_mutex);
		return -EACCES;
	}

	obj = container_of(node, struct drm_gem_object, vma_node);
	ret = rockchip_gem_mmap_buf(obj, vma);

	mutex_unlock(&dev->struct_mutex);

	return ret;
}

struct rockchip_gem_object *
	rockchip_gem_create_object(struct drm_device *drm, unsigned int size)
{
	struct rockchip_gem_object *rk_obj;
	struct drm_gem_object *obj;
	int ret;

	size = round_up(size, PAGE_SIZE);

	rk_obj = kzalloc(sizeof(*rk_obj), GFP_KERNEL);
	if (!rk_obj)
		return ERR_PTR(-ENOMEM);

	obj = &rk_obj->base;

	drm_gem_private_object_init(drm, obj, size);

	ret = rockchip_gem_alloc_buf(rk_obj);
	if (ret)
		goto err_free_rk_obj;

	return rk_obj;

err_free_rk_obj:
	kfree(rk_obj);
	return ERR_PTR(ret);
}

/*
 * rockchip_gem_free_object - (struct drm_driver)->gem_free_object callback
 * function
 */
void rockchip_gem_free_object(struct drm_gem_object *obj)
{
	struct rockchip_gem_object *rk_obj;

	drm_gem_free_mmap_offset(obj);

	rk_obj = to_rockchip_obj(obj);

	rockchip_gem_free_buf(rk_obj);

	kfree(rk_obj);
}

/*
 * rockchip_gem_create_with_handle - allocate an object with the given
 * size and create a gem handle on it
 *
 * returns a struct rockchip_gem_object* on success or ERR_PTR values
 * on failure.
 */
static struct rockchip_gem_object *
rockchip_gem_create_with_handle(struct drm_file *file_priv,
				struct drm_device *drm, unsigned int size,
				unsigned int *handle)
{
	struct rockchip_gem_object *rk_obj;
	struct drm_gem_object *obj;
	int ret;

	rk_obj = rockchip_gem_create_object(drm, size);
	if (IS_ERR(rk_obj))
		return ERR_CAST(rk_obj);

	obj = &rk_obj->base;

	/*
	 * allocate a id of idr table where the obj is registered
	 * and handle has the id what user can see.
	 */
	ret = drm_gem_handle_create(file_priv, obj, handle);
	if (ret)
		goto err_handle_create;

	/* drop reference from allocate - handle holds it now. */
	drm_gem_object_unreference_unlocked(obj);

	return rk_obj;

err_handle_create:
	rockchip_gem_free_object(obj);

	return ERR_PTR(ret);
}

int rockchip_gem_dumb_map_offset(struct drm_file *file_priv,
				 struct drm_device *dev, uint32_t handle,
				 uint64_t *offset)
{
	struct drm_gem_object *obj;
	int ret;

	mutex_lock(&dev->struct_mutex);

	obj = drm_gem_object_lookup(dev, file_priv, handle);
	if (!obj) {
		DRM_ERROR("failed to lookup gem object.\n");
		ret = -EINVAL;
		goto unlock;
	}

	ret = drm_gem_create_mmap_offset(obj);
	if (ret)
		goto out;

	*offset = drm_vma_node_offset_addr(&obj->vma_node);
	DRM_DEBUG_KMS("offset = 0x%llx\n", *offset);

out:
	drm_gem_object_unreference(obj);
unlock:
	mutex_unlock(&dev->struct_mutex);
	return ret;
}

/*
 * rockchip_gem_dumb_create - (struct drm_driver)->dumb_create callback
 * function
 *
 * This aligns the pitch and size arguments to the minimum required. wrap
 * this into your own function if you need bigger alignment.
 */
int rockchip_gem_dumb_create(struct drm_file *file_priv,
			     struct drm_device *dev,
			     struct drm_mode_create_dumb *args)
{
	struct rockchip_gem_object *rk_obj;
	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);

	/*
	 * align to 64 bytes since Mali requires it.
	 */
	min_pitch = ALIGN(min_pitch, 64);

	if (args->pitch < min_pitch)
		args->pitch = min_pitch;

	if (args->size < args->pitch * args->height)
		args->size = args->pitch * args->height;

	rk_obj = rockchip_gem_create_with_handle(file_priv, dev, args->size,
						 &args->handle);

	return PTR_ERR_OR_ZERO(rk_obj);
}

/*
 * Allocate a sg_table for this GEM object.
 * Note: Both the table's contents, and the sg_table itself must be freed by
 *       the caller.
 * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
 */
struct sg_table *rockchip_gem_prime_get_sg_table(struct drm_gem_object *obj)
{
	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
	struct drm_device *drm = obj->dev;
	struct sg_table *sgt;
	int ret;

	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
	if (!sgt)
		return ERR_PTR(-ENOMEM);

	ret = dma_get_sgtable_attrs(drm->dev, sgt, rk_obj->kvaddr,
				    rk_obj->dma_addr, obj->size,
				    &rk_obj->dma_attrs);
	if (ret) {
		DRM_ERROR("failed to allocate sgt, %d\n", ret);
		kfree(sgt);
		return ERR_PTR(ret);
	}

	return sgt;
}

void *rockchip_gem_prime_vmap(struct drm_gem_object *obj)
{
	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);

	return rk_obj->kvaddr;
}

void rockchip_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
{
	/* Nothing to do */
}