#include "char.h"

#include <linux/anon_inodes.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <asm/uaccess.h>

#include "doomdev.h"
#include "harddoom.h"
#include "util.h"
#include "pci.h"
#include "surface.h"

#define DOOMDEV_COUNT 256
#define DOOMDEV_NAME "doom"

dev_t first;
int major;
int next_minor = 0;

long doom_create_surface(struct file *filp, unsigned long arg)
{
	struct doomdev_ioctl_create_surface *params;

	params = (struct doomdev_ioctl_create_surface *)arg;
	return new_surface(filp, params);
}

void free_texture(struct texture_data *texture_data);
int texture_release(struct inode *inode, struct file *filp)
{
	struct texture_data *texture_data;

	texture_data = filp->private_data;

	free_texture(texture_data);

	kfree(texture_data);

	return 0;
}

struct file_operations texture_fops = {
	.owner = THIS_MODULE,
	.release = texture_release

};

int verify_texture_params(struct doomdev_ioctl_create_texture *params)
{
	if (params->size > 4 * 1024 * 1024) {
		return -EOVERFLOW;
	}

	if (params->height > 1023) {
		return -EOVERFLOW;
	}

	return 0;
}

int alloc_texture(struct doomdev_ioctl_create_texture *params,
	       struct texture_data *texture_data)
{
	int err;
	int i;
	int not_written;
	int pages_needed;

	texture_data->size = params->size;
	texture_data->height = params->height;

	pages_needed = (params->size / HARDDOOM_PAGE_SIZE);
	if (params->size % HARDDOOM_PAGE_SIZE != 0) {
		pages_needed += 1;
	}

	texture_data->pages = pages_needed;
	texture_data->texture_cpu =
		dma_alloc_coherent(texture_data->doom_data->pci_device,
				params->size, &texture_data->texture_dev,
				GFP_KERNEL);
	ORFAIL_NULL(texture_data->texture_cpu, -ENOMEM, error_texture);

	texture_data->page_table_cpu = 
		dma_alloc_coherent(texture_data->doom_data->pci_device,
				pages_needed * 4, &texture_data->page_table_dev,
				GFP_KERNEL);
	ORFAIL_NULL(texture_data->page_table_cpu, -ENOMEM, error_pt);

	for (i = 0; i < pages_needed; i++) {
		texture_data->page_table_cpu[i] =
			(HARDDOOM_PTE_PHYS_MASK &
			 (texture_data->texture_dev + HARDDOOM_PAGE_SIZE * i)) |
			HARDDOOM_PTE_VALID;
	}

	not_written = copy_from_user(texture_data->texture_cpu,
			(void __user *) params->data_ptr,
			params->size);


	if (not_written) {
		err = -EFAULT;
		goto error_copy;
	}

	return 0;

error_copy:
	dma_free_coherent(texture_data->doom_data->pci_device,
			texture_data->pages * 4, texture_data->page_table_cpu,
			texture_data->page_table_dev);
error_pt:
	dma_free_coherent(texture_data->doom_data->pci_device,
			texture_data->size, texture_data->texture_cpu,
			texture_data->texture_dev);
error_texture:
	return err;
}

void free_texture(struct texture_data *texture_data)
{
	dma_free_coherent(texture_data->doom_data->pci_device,
			texture_data->pages * 4, texture_data->page_table_cpu,
			texture_data->page_table_dev);

	dma_free_coherent(texture_data->doom_data->pci_device,
			texture_data->size, texture_data->texture_cpu,
			texture_data->texture_dev);
}

long doom_create_texture(struct file *filp, unsigned long arg)
{
	int err;
	struct doomdev_ioctl_create_texture *params;
	struct texture_data *texture_data;
	int fd;
	struct doom_data *doom_data;

	params = (struct doomdev_ioctl_create_texture *) arg;

	err = verify_texture_params(params);
	if (err < 0) {
		return err;
	}

	texture_data = kmalloc(sizeof(*texture_data), GFP_KERNEL);
	ORFAIL_NULL(texture_data, -ENOMEM, error_data);
	doom_data = container_of(filp->f_inode->i_cdev, struct doom_data, cdev);
	texture_data->doom_data = doom_data;
	
	ORFAIL(alloc_texture(params, texture_data), error_texture);

	fd = anon_inode_getfd("doom_texture", &texture_fops, texture_data, 0);
	ORFAIL(fd, error_inode);

	return fd;

error_inode:
	free_texture(texture_data);
error_texture:
	kfree(texture_data);
error_data:
	return err;
}

void free_flat(struct flat_data *flat_data);
int flat_release(struct inode *inode, struct file *filp)
{
	struct flat_data *flat_data;

	flat_data = filp->private_data;

	free_flat(flat_data);

	kfree(flat_data);

	return 0;
}

struct file_operations flat_fops = {
	.owner = THIS_MODULE,
	.release = flat_release

};

int alloc_flat(struct doomdev_ioctl_create_flat *params,
		struct flat_data *flat_data)
{
	int err;
	int not_written;

	flat_data->flat_cpu =
		dma_alloc_coherent(flat_data->doom_data->pci_device,
				HARDDOOM_FLAT_SIZE, &flat_data->flat_dev,
				GFP_KERNEL);
	ORFAIL_NULL(flat_data->flat_cpu, -ENOMEM, error_flat);

	not_written = copy_from_user(flat_data->flat_cpu,
			(void __user *) params->data_ptr, HARDDOOM_FLAT_SIZE);

	if (not_written) {
		p("some bytes not copied\n");
		err = -EFAULT;
		goto error_copy;
	}

	return 0;

error_copy:
	dma_free_coherent(flat_data->doom_data->pci_device, HARDDOOM_FLAT_SIZE,
			flat_data->flat_cpu, flat_data->flat_dev);
error_flat:
	return err;

}

void free_flat(struct flat_data *flat_data)
{
	dma_free_coherent(flat_data->doom_data->pci_device, HARDDOOM_FLAT_SIZE,
			flat_data->flat_cpu, flat_data->flat_dev);
}

long doom_create_flat(struct file *filp, unsigned long arg)
{
	int err;
	struct doomdev_ioctl_create_flat *params;
	struct flat_data *flat_data;
	int fd;
	struct doom_data *doom_data;

	params = (struct doomdev_ioctl_create_flat *) arg;

	flat_data = kmalloc(sizeof(*flat_data), GFP_KERNEL);
	ORFAIL_NULL(flat_data, -ENOMEM, error_data);
	doom_data = container_of(filp->f_inode->i_cdev, struct doom_data, cdev);
	flat_data->doom_data = doom_data;
	
	ORFAIL(alloc_flat(params, flat_data), error_flat);

	fd = anon_inode_getfd("doom_texture", &flat_fops, flat_data, 0);
	ORFAIL(fd, error_inode);

	return fd;

error_inode:
	free_flat(flat_data);
error_flat:
	kfree(flat_data);
error_data:
	return err;
}

long doom_create_colormaps(struct file *filp, unsigned long arg)
{
	return -1;
}

long doom_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	switch (cmd) {
	case DOOMDEV_IOCTL_CREATE_SURFACE:
		return doom_create_surface(filp, arg);
	case DOOMDEV_IOCTL_CREATE_TEXTURE:
		return doom_create_texture(filp, arg);
	case DOOMDEV_IOCTL_CREATE_FLAT:
		return doom_create_flat(filp, arg);
	case DOOMDEV_IOCTL_CREATE_COLORMAPS:
		return doom_create_colormaps(filp, arg);
	default:
		return -EINVAL;
	}
}

int doom_open(struct inode *inode, struct file *filp)
{
	return 0;
}

struct file_operations doomdev_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = doom_ioctl,
	.compat_ioctl = doom_ioctl,
	.open = doom_open
};
	
struct class *doom_class;

int new_doomdev(struct pci_dev *dev)
{
	int err = 0;
	int minor;
	struct doom_data *doom_data;
	dev_t devt;

	if (next_minor >= DOOMDEV_COUNT) {
		return -ENOMEM;
	}

	doom_data = pci_get_drvdata(dev);

	cdev_init(&doom_data->cdev, &doomdev_fops);
	ORFAIL(cdev_add(&doom_data->cdev, first, 1), error_add);

	minor = next_minor++;
	devt = MKDEV(major, minor);
	doom_data->device = device_create(doom_class, &dev->dev, devt, NULL,
				"doom%d", minor);
	ORFAIL_PTR(doom_data->device, error_create);

	return 0;

error_create:
	cdev_del(&doom_data->cdev);
error_add:
	return err;
}

void destroy_doomdev(struct doom_data *doom_data)
{
	device_destroy(doom_class, doom_data->device->devt);
	cdev_del(&doom_data->cdev);
}

int char_init(void)
{
	int err = 0;

	ORFAIL(alloc_chrdev_region(&first, 0, DOOMDEV_COUNT, DOOMDEV_NAME),
			error_region);
	major = MAJOR(first);
	doom_class = class_create(THIS_MODULE, "doom");
	ORFAIL_PTR(doom_class, error_create);

	return 0;

error_create:
	unregister_chrdev_region(first, DOOMDEV_COUNT);
error_region:
	return err;
}

void char_cleanup(void)
{
	unregister_chrdev_region(first, DOOMDEV_COUNT);
	class_unregister(doom_class);
	class_destroy(doom_class);
}