frontend.c

linux-2.6.15.6

	struct agp_client *client;
	struct agp_client *prev_client;
	struct agp_client *next_client;
	struct agp_controller *controller;

	controller = agp_find_controller_for_client(id);
	if (controller == NULL)
		return -EINVAL;

	client = agp_find_client_in_controller(controller, id);
	if (client == NULL)
		return -EINVAL;

	prev_client = client->prev;
	next_client = client->next;

	if (prev_client != NULL) {
		prev_client->next = next_client;
		if (next_client != NULL)
			next_client->prev = prev_client;

	} else {
		if (next_client != NULL)
			next_client->prev = NULL;
		controller->clients = next_client;
	}

	controller->num_clients--;
	agp_remove_seg_from_client(client);
	kfree(client);
	return 0;
}

/* End - Routines for managing client lists */

/* File Operations */

static int agp_mmap(struct file *file, struct vm_area_struct *vma)
{
	unsigned int size, current_size;
	unsigned long offset;
	struct agp_client *client;
	struct agp_file_private *priv = file->private_data;
	struct agp_kern_info kerninfo;

	down(&(agp_fe.agp_mutex));

	if (agp_fe.backend_acquired != TRUE)
		goto out_eperm;

	if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
		goto out_eperm;

	agp_copy_info(agp_bridge, &kerninfo);
	size = vma->vm_end - vma->vm_start;
	current_size = kerninfo.aper_size;
	current_size = current_size * 0x100000;
	offset = vma->vm_pgoff << PAGE_SHIFT;
	DBG("%lx:%lx", offset, offset+size);

	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
		if ((size + offset) > current_size)
			goto out_inval;

		client = agp_find_client_by_pid(current->pid);

		if (client == NULL)
			goto out_eperm;

		if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
			goto out_inval;

		DBG("client vm_ops=%p", kerninfo.vm_ops);
		if (kerninfo.vm_ops) {
			vma->vm_ops = kerninfo.vm_ops;
		} else if (io_remap_pfn_range(vma, vma->vm_start,
				(kerninfo.aper_base + offset) >> PAGE_SHIFT,
					    size, vma->vm_page_prot)) {
			goto out_again;
		}
		up(&(agp_fe.agp_mutex));
		return 0;
	}

	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
		if (size != current_size)
			goto out_inval;

		DBG("controller vm_ops=%p", kerninfo.vm_ops);
		if (kerninfo.vm_ops) {
			vma->vm_ops = kerninfo.vm_ops;
		} else if (io_remap_pfn_range(vma, vma->vm_start,
					    kerninfo.aper_base >> PAGE_SHIFT,
					    size, vma->vm_page_prot)) {
			goto out_again;
		}
		up(&(agp_fe.agp_mutex));
		return 0;
	}

out_eperm:
	up(&(agp_fe.agp_mutex));
	return -EPERM;

out_inval:
	up(&(agp_fe.agp_mutex));
	return -EINVAL;

out_again:
	up(&(agp_fe.agp_mutex));
	return -EAGAIN;
}

static int agp_release(struct inode *inode, struct file *file)
{
	struct agp_file_private *priv = file->private_data;

	down(&(agp_fe.agp_mutex));

	DBG("priv=%p", priv);

	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
		struct agp_controller *controller;

		controller = agp_find_controller_by_pid(priv->my_pid);

		if (controller != NULL) {
			if (controller == agp_fe.current_controller)
				agp_controller_release_current(controller, priv);
			agp_remove_controller(controller);
			controller = NULL;
		}
	}

	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags))
		agp_remove_client(priv->my_pid);

	agp_remove_file_private(priv);
	kfree(priv);
	file->private_data = NULL;
	up(&(agp_fe.agp_mutex));
	return 0;
}

static int agp_open(struct inode *inode, struct file *file)
{
	int minor = iminor(inode);
	struct agp_file_private *priv;
	struct agp_client *client;
	int rc = -ENXIO;

	down(&(agp_fe.agp_mutex));

	if (minor != AGPGART_MINOR)
		goto err_out;

	priv = kzalloc(sizeof(struct agp_file_private), GFP_KERNEL);
	if (priv == NULL)
		goto err_out_nomem;

	set_bit(AGP_FF_ALLOW_CLIENT, &priv->access_flags);
	priv->my_pid = current->pid;

	if ((current->uid == 0) || (current->suid == 0)) {
		/* Root priv, can be controller */
		set_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags);
	}
	client = agp_find_client_by_pid(current->pid);

	if (client != NULL) {
		set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
		set_bit(AGP_FF_IS_VALID, &priv->access_flags);
	}
	file->private_data = (void *) priv;
	agp_insert_file_private(priv);
	DBG("private=%p, client=%p", priv, client);
	up(&(agp_fe.agp_mutex));
	return 0;

err_out_nomem:
	rc = -ENOMEM;
err_out:
	up(&(agp_fe.agp_mutex));
	return rc;
}


static ssize_t agp_read(struct file *file, char __user *buf,
			size_t count, loff_t * ppos)
{
	return -EINVAL;
}

static ssize_t agp_write(struct file *file, const char __user *buf,
			 size_t count, loff_t * ppos)
{
	return -EINVAL;
}

static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
{
	struct agp_info userinfo;
	struct agp_kern_info kerninfo;

	agp_copy_info(agp_bridge, &kerninfo);

	userinfo.version.major = kerninfo.version.major;
	userinfo.version.minor = kerninfo.version.minor;
	userinfo.bridge_id = kerninfo.device->vendor |
	    (kerninfo.device->device << 16);
	userinfo.agp_mode = kerninfo.mode;
	userinfo.aper_base = kerninfo.aper_base;
	userinfo.aper_size = kerninfo.aper_size;
	userinfo.pg_total = userinfo.pg_system = kerninfo.max_memory;
	userinfo.pg_used = kerninfo.current_memory;

	if (copy_to_user(arg, &userinfo, sizeof(struct agp_info)))
		return -EFAULT;

	return 0;
}

static int agpioc_acquire_wrap(struct agp_file_private *priv)
{
	struct agp_controller *controller;

	DBG("");

	if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
		return -EPERM;

	if (agp_fe.current_controller != NULL)
		return -EBUSY;

	if(!agp_bridge)
		return -ENODEV;

        if (atomic_read(&agp_bridge->agp_in_use))
                return -EBUSY;

	atomic_inc(&agp_bridge->agp_in_use);

	agp_fe.backend_acquired = TRUE;

	controller = agp_find_controller_by_pid(priv->my_pid);

	if (controller != NULL) {
		agp_controller_make_current(controller);
	} else {
		controller = agp_create_controller(priv->my_pid);

		if (controller == NULL) {
			agp_fe.backend_acquired = FALSE;
			agp_backend_release(agp_bridge);
			return -ENOMEM;
		}
		agp_insert_controller(controller);
		agp_controller_make_current(controller);
	}

	set_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags);
	set_bit(AGP_FF_IS_VALID, &priv->access_flags);
	return 0;
}

static int agpioc_release_wrap(struct agp_file_private *priv)
{
	DBG("");
	agp_controller_release_current(agp_fe.current_controller, priv);
	return 0;
}

static int agpioc_setup_wrap(struct agp_file_private *priv, void __user *arg)
{
	struct agp_setup mode;

	DBG("");
	if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
		return -EFAULT;

	agp_enable(agp_bridge, mode.agp_mode);
	return 0;
}

static int agpioc_reserve_wrap(struct agp_file_private *priv, void __user *arg)
{
	struct agp_region reserve;
	struct agp_client *client;
	struct agp_file_private *client_priv;

	DBG("");
	if (copy_from_user(&reserve, arg, sizeof(struct agp_region)))
		return -EFAULT;

	if ((unsigned) reserve.seg_count >= ~0U/sizeof(struct agp_segment))
		return -EFAULT;

	client = agp_find_client_by_pid(reserve.pid);

	if (reserve.seg_count == 0) {
		/* remove a client */
		client_priv = agp_find_private(reserve.pid);

		if (client_priv != NULL) {
			set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
			set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
		}
		if (client == NULL) {
			/* client is already removed */
			return 0;
		}
		return agp_remove_client(reserve.pid);
	} else {
		struct agp_segment *segment;

		if (reserve.seg_count >= 16384)
			return -EINVAL;

		segment = kmalloc((sizeof(struct agp_segment) * reserve.seg_count),
				  GFP_KERNEL);

		if (segment == NULL)
			return -ENOMEM;

		if (copy_from_user(segment, (void __user *) reserve.seg_list,
				   sizeof(struct agp_segment) * reserve.seg_count)) {
			kfree(segment);
			return -EFAULT;
		}
		reserve.seg_list = segment;

		if (client == NULL) {
			/* Create the client and add the segment */
			client = agp_create_client(reserve.pid);

			if (client == NULL) {
				kfree(segment);
				return -ENOMEM;
			}
			client_priv = agp_find_private(reserve.pid);

			if (client_priv != NULL) {
				set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
				set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
			}
		}
		return agp_create_segment(client, &reserve);
	}
	/* Will never really happen */
	return -EINVAL;
}

static int agpioc_protect_wrap(struct agp_file_private *priv)
{
	DBG("");
	/* This function is not currently implemented */
	return -EINVAL;
}

static int agpioc_allocate_wrap(struct agp_file_private *priv, void __user *arg)
{
	struct agp_memory *memory;
	struct agp_allocate alloc;

	DBG("");
	if (copy_from_user(&alloc, arg, sizeof(struct agp_allocate)))
		return -EFAULT;

	memory = agp_allocate_memory_wrap(alloc.pg_count, alloc.type);

	if (memory == NULL)
		return -ENOMEM;

	alloc.key = memory->key;
	alloc.physical = memory->physical;

	if (copy_to_user(arg, &alloc, sizeof(struct agp_allocate))) {
		agp_free_memory_wrap(memory);
		return -EFAULT;
	}
	return 0;
}

static int agpioc_deallocate_wrap(struct agp_file_private *priv, int arg)
{
	struct agp_memory *memory;

	DBG("");
	memory = agp_find_mem_by_key(arg);

	if (memory == NULL)
		return -EINVAL;

	agp_free_memory_wrap(memory);
	return 0;
}

static int agpioc_bind_wrap(struct agp_file_private *priv, void __user *arg)
{
	struct agp_bind bind_info;
	struct agp_memory *memory;

	DBG("");
	if (copy_from_user(&bind_info, arg, sizeof(struct agp_bind)))
		return -EFAULT;

	memory = agp_find_mem_by_key(bind_info.key);

	if (memory == NULL)
		return -EINVAL;

	return agp_bind_memory(memory, bind_info.pg_start);
}

static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
{
	struct agp_memory *memory;
	struct agp_unbind unbind;

	DBG("");
	if (copy_from_user(&unbind, arg, sizeof(struct agp_unbind)))
		return -EFAULT;

	memory = agp_find_mem_by_key(unbind.key);

	if (memory == NULL)
		return -EINVAL;

	return agp_unbind_memory(memory);
}

static int agp_ioctl(struct inode *inode, struct file *file,
		     unsigned int cmd, unsigned long arg)
{
	struct agp_file_private *curr_priv = file->private_data;
	int ret_val = -ENOTTY;

	DBG("priv=%p, cmd=%x", curr_priv, cmd);
	down(&(agp_fe.agp_mutex));

	if ((agp_fe.current_controller == NULL) &&
	    (cmd != AGPIOC_ACQUIRE)) {
		ret_val = -EINVAL;
		goto ioctl_out;
	}
	if ((agp_fe.backend_acquired != TRUE) &&
	    (cmd != AGPIOC_ACQUIRE)) {
		ret_val = -EBUSY;
		goto ioctl_out;
	}
	if (cmd != AGPIOC_ACQUIRE) {
		if (!(test_bit(AGP_FF_IS_CONTROLLER, &curr_priv->access_flags))) {
			ret_val = -EPERM;
			goto ioctl_out;
		}
		/* Use the original pid of the controller,
		 * in case it's threaded */

		if (agp_fe.current_controller->pid != curr_priv->my_pid) {
			ret_val = -EBUSY;
			goto ioctl_out;
		}
	}

	switch (cmd) {
	case AGPIOC_INFO:
		ret_val = agpioc_info_wrap(curr_priv, (void __user *) arg);
		break;

	case AGPIOC_ACQUIRE:
		ret_val = agpioc_acquire_wrap(curr_priv);
		break;

	case AGPIOC_RELEASE:
		ret_val = agpioc_release_wrap(curr_priv);
		break;

	case AGPIOC_SETUP:
		ret_val = agpioc_setup_wrap(curr_priv, (void __user *) arg);
		break;

	case AGPIOC_RESERVE:
		ret_val = agpioc_reserve_wrap(curr_priv, (void __user *) arg);
		break;

	case AGPIOC_PROTECT:
		ret_val = agpioc_protect_wrap(curr_priv);
		break;

	case AGPIOC_ALLOCATE:
		ret_val = agpioc_allocate_wrap(curr_priv, (void __user *) arg);
		break;

	case AGPIOC_DEALLOCATE:
		ret_val = agpioc_deallocate_wrap(curr_priv, (int) arg);
		break;

	case AGPIOC_BIND:
		ret_val = agpioc_bind_wrap(curr_priv, (void __user *) arg);
		break;

	case AGPIOC_UNBIND:
		ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
		break;
	}

ioctl_out:
	DBG("ioctl returns %d\n", ret_val);
	up(&(agp_fe.agp_mutex));
	return ret_val;
}

static struct file_operations agp_fops =
{
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= agp_read,
	.write		= agp_write,
	.ioctl		= agp_ioctl,
	.mmap		= agp_mmap,
	.open		= agp_open,
	.release	= agp_release,
};

static struct miscdevice agp_miscdev =
{
	.minor	= AGPGART_MINOR,
	.name	= "agpgart",
	.fops	= &agp_fops
};

int agp_frontend_initialize(void)
{
	memset(&agp_fe, 0, sizeof(struct agp_front_data));
	sema_init(&(agp_fe.agp_mutex), 1);

	if (misc_register(&agp_miscdev)) {
		printk(KERN_ERR PFX "unable to get minor: %d\n", AGPGART_MINOR);
		return -EIO;
	}
	return 0;
}

void agp_frontend_cleanup(void)
{
	misc_deregister(&agp_miscdev);
}