[linux-2.6-block.git] / drivers / uio / uio.c

/*
 * drivers/uio/uio.c
 *
 * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
 * Copyright(C) 2006, Hans J. Koch <hjk@linutronix.de>
 * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
 *
 * Userspace IO
 *
 * Base Functions
 *
 * Licensed under the GPLv2 only.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/device.h>
#include <linux/mm.h>
#include <linux/idr.h>
#include <linux/string.h>
#include <linux/kobject.h>
#include <linux/uio_driver.h>

#define UIO_MAX_DEVICES 255

struct uio_device {
	struct module		*owner;
	struct device		*dev;
	int			minor;
	atomic_t		event;
	struct fasync_struct	*async_queue;
	wait_queue_head_t	wait;
	int			vma_count;
	struct uio_info		*info;
	struct kobject		*map_dir;
};

static int uio_major;
static DEFINE_IDR(uio_idr);
static const struct file_operations uio_fops;

/* UIO class infrastructure */
static struct uio_class {
	struct kref kref;
	struct class *class;
} *uio_class;

/*
 * attributes
 */

struct uio_map {
	struct kobject kobj;
	struct uio_mem *mem;
};
#define to_map(map) container_of(map, struct uio_map, kobj)


static ssize_t map_attr_show(struct kobject *kobj, struct kobj_attribute *attr,
			     char *buf)
{
	struct uio_map *map = to_map(kobj);
	struct uio_mem *mem = map->mem;

	if (strncmp(attr->attr.name, "addr", 4) == 0)
		return sprintf(buf, "0x%lx\n", mem->addr);

	if (strncmp(attr->attr.name, "size", 4) == 0)
		return sprintf(buf, "0x%lx\n", mem->size);

	return -ENODEV;
}

static struct kobj_attribute attr_attribute =
	__ATTR(addr, S_IRUGO, map_attr_show, NULL);
static struct kobj_attribute size_attribute =
	__ATTR(size, S_IRUGO, map_attr_show, NULL);

static struct attribute *attrs[] = {
	&attr_attribute.attr,
	&size_attribute.attr,
	NULL,	/* need to NULL terminate the list of attributes */
};

static void map_release(struct kobject *kobj)
{
	struct uio_map *map = to_map(kobj);
	kfree(map);
}

static struct kobj_type map_attr_type = {
	.release	= map_release,
	.default_attrs	= attrs,
};

static ssize_t show_name(struct device *dev,
			 struct device_attribute *attr, char *buf)
{
	struct uio_device *idev = dev_get_drvdata(dev);
	if (idev)
		return sprintf(buf, "%s\n", idev->info->name);
	else
		return -ENODEV;
}
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);

static ssize_t show_version(struct device *dev,
			    struct device_attribute *attr, char *buf)
{
	struct uio_device *idev = dev_get_drvdata(dev);
	if (idev)
		return sprintf(buf, "%s\n", idev->info->version);
	else
		return -ENODEV;
}
static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);

static ssize_t show_event(struct device *dev,
			  struct device_attribute *attr, char *buf)
{
	struct uio_device *idev = dev_get_drvdata(dev);
	if (idev)
		return sprintf(buf, "%u\n",
				(unsigned int)atomic_read(&idev->event));
	else
		return -ENODEV;
}
static DEVICE_ATTR(event, S_IRUGO, show_event, NULL);

static struct attribute *uio_attrs[] = {
	&dev_attr_name.attr,
	&dev_attr_version.attr,
	&dev_attr_event.attr,
	NULL,
};

static struct attribute_group uio_attr_grp = {
	.attrs = uio_attrs,
};

/*
 * device functions
 */
static int uio_dev_add_attributes(struct uio_device *idev)
{
	int ret;
	int mi;
	int map_found = 0;
	struct uio_mem *mem;
	struct uio_map *map;

	ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp);
	if (ret)
		goto err_group;

	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
		mem = &idev->info->mem[mi];
		if (mem->size == 0)
			break;
		if (!map_found) {
			map_found = 1;
			idev->map_dir = kobject_create_and_add("maps",
							&idev->dev->kobj);
			if (!idev->map_dir)
				goto err;
		}
		map = kzalloc(sizeof(*map), GFP_KERNEL);
		if (!map)
			goto err;
		kobject_init(&map->kobj, &map_attr_type);
		map->mem = mem;
		mem->map = map;
		ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
		if (ret)
			goto err;
		ret = kobject_uevent(&map->kobj, KOBJ_ADD);
		if (ret)
			goto err;
	}

	return 0;

err:
	for (mi--; mi>=0; mi--) {
		mem = &idev->info->mem[mi];
		map = mem->map;
		kobject_put(&map->kobj);
	}
	kobject_put(idev->map_dir);
	sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
err_group:
	dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
	return ret;
}

static void uio_dev_del_attributes(struct uio_device *idev)
{
	int mi;
	struct uio_mem *mem;
	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
		mem = &idev->info->mem[mi];
		if (mem->size == 0)
			break;
		kobject_put(&mem->map->kobj);
	}
	kobject_put(idev->map_dir);
	sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
}

static int uio_get_minor(struct uio_device *idev)
{
	static DEFINE_MUTEX(minor_lock);
	int retval = -ENOMEM;
	int id;

	mutex_lock(&minor_lock);
	if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0)
		goto exit;

	retval = idr_get_new(&uio_idr, idev, &id);
	if (retval < 0) {
		if (retval == -EAGAIN)
			retval = -ENOMEM;
		goto exit;
	}
	idev->minor = id & MAX_ID_MASK;
exit:
	mutex_unlock(&minor_lock);
	return retval;
}

static void uio_free_minor(struct uio_device *idev)
{
	idr_remove(&uio_idr, idev->minor);
}

/**
 * uio_event_notify - trigger an interrupt event
 * @info: UIO device capabilities
 */
void uio_event_notify(struct uio_info *info)
{
	struct uio_device *idev = info->uio_dev;

	atomic_inc(&idev->event);
	wake_up_interruptible(&idev->wait);
	kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
}
EXPORT_SYMBOL_GPL(uio_event_notify);

/**
 * uio_interrupt - hardware interrupt handler
 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
 * @dev_id: Pointer to the devices uio_device structure
 */
static irqreturn_t uio_interrupt(int irq, void *dev_id)
{
	struct uio_device *idev = (struct uio_device *)dev_id;
	irqreturn_t ret = idev->info->handler(irq, idev->info);

	if (ret == IRQ_HANDLED)
		uio_event_notify(idev->info);

	return ret;
}

struct uio_listener {
	struct uio_device *dev;
	s32 event_count;
};

static int uio_open(struct inode *inode, struct file *filep)
{
	struct uio_device *idev;
	struct uio_listener *listener;
	int ret = 0;

	idev = idr_find(&uio_idr, iminor(inode));
	if (!idev)
		return -ENODEV;

	listener = kmalloc(sizeof(*listener), GFP_KERNEL);
	if (!listener)
		return -ENOMEM;

	listener->dev = idev;
	listener->event_count = atomic_read(&idev->event);
	filep->private_data = listener;

	if (idev->info->open) {
		if (!try_module_get(idev->owner))
			return -ENODEV;
		ret = idev->info->open(idev->info, inode);
		module_put(idev->owner);
	}

	if (ret)
		kfree(listener);

	return ret;
}

static int uio_fasync(int fd, struct file *filep, int on)
{
	struct uio_listener *listener = filep->private_data;
	struct uio_device *idev = listener->dev;

	return fasync_helper(fd, filep, on, &idev->async_queue);
}

static int uio_release(struct inode *inode, struct file *filep)
{
	int ret = 0;
	struct uio_listener *listener = filep->private_data;
	struct uio_device *idev = listener->dev;

	if (idev->info->release) {
		if (!try_module_get(idev->owner))
			return -ENODEV;
		ret = idev->info->release(idev->info, inode);
		module_put(idev->owner);
	}
	if (filep->f_flags & FASYNC)
		ret = uio_fasync(-1, filep, 0);
	kfree(listener);
	return ret;
}

static unsigned int uio_poll(struct file *filep, poll_table *wait)
{
	struct uio_listener *listener = filep->private_data;
	struct uio_device *idev = listener->dev;

	if (idev->info->irq == UIO_IRQ_NONE)
		return -EIO;

	poll_wait(filep, &idev->wait, wait);
	if (listener->event_count != atomic_read(&idev->event))
		return POLLIN | POLLRDNORM;
	return 0;
}

static ssize_t uio_read(struct file *filep, char __user *buf,
			size_t count, loff_t *ppos)
{
	struct uio_listener *listener = filep->private_data;
	struct uio_device *idev = listener->dev;
	DECLARE_WAITQUEUE(wait, current);
	ssize_t retval;
	s32 event_count;

	if (idev->info->irq == UIO_IRQ_NONE)
		return -EIO;

	if (count != sizeof(s32))
		return -EINVAL;

	add_wait_queue(&idev->wait, &wait);

	do {
		set_current_state(TASK_INTERRUPTIBLE);

		event_count = atomic_read(&idev->event);
		if (event_count != listener->event_count) {
			if (copy_to_user(buf, &event_count, count))
				retval = -EFAULT;
			else {
				listener->event_count = event_count;
				retval = count;
			}
			break;
		}

		if (filep->f_flags & O_NONBLOCK) {
			retval = -EAGAIN;
			break;
		}

		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		schedule();
	} while (1);

	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&idev->wait, &wait);

	return retval;
}

static int uio_find_mem_index(struct vm_area_struct *vma)
{
	int mi;
	struct uio_device *idev = vma->vm_private_data;

	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
		if (idev->info->mem[mi].size == 0)
			return -1;
		if (vma->vm_pgoff == mi)
			return mi;
	}
	return -1;
}

static void uio_vma_open(struct vm_area_struct *vma)
{
	struct uio_device *idev = vma->vm_private_data;
	idev->vma_count++;
}

static void uio_vma_close(struct vm_area_struct *vma)
{
	struct uio_device *idev = vma->vm_private_data;
	idev->vma_count--;
}

static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct uio_device *idev = vma->vm_private_data;
	struct page *page;

	int mi = uio_find_mem_index(vma);
	if (mi < 0)
		return VM_FAULT_SIGBUS;

	if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
		page = virt_to_page(idev->info->mem[mi].addr);
	else
		page = vmalloc_to_page((void*)idev->info->mem[mi].addr);
	get_page(page);
	vmf->page = page;
	return 0;
}

static struct vm_operations_struct uio_vm_ops = {
	.open = uio_vma_open,
	.close = uio_vma_close,
	.fault = uio_vma_fault,
};

static int uio_mmap_physical(struct vm_area_struct *vma)
{
	struct uio_device *idev = vma->vm_private_data;
	int mi = uio_find_mem_index(vma);
	if (mi < 0)
		return -EINVAL;

	vma->vm_flags |= VM_IO | VM_RESERVED;

	return remap_pfn_range(vma,
			       vma->vm_start,
			       idev->info->mem[mi].addr >> PAGE_SHIFT,
			       vma->vm_end - vma->vm_start,
			       vma->vm_page_prot);
}

static int uio_mmap_logical(struct vm_area_struct *vma)
{
	vma->vm_flags |= VM_RESERVED;
	vma->vm_ops = &uio_vm_ops;
	uio_vma_open(vma);
	return 0;
}

static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
{
	struct uio_listener *listener = filep->private_data;
	struct uio_device *idev = listener->dev;
	int mi;
	unsigned long requested_pages, actual_pages;
	int ret = 0;

	if (vma->vm_end < vma->vm_start)
		return -EINVAL;

	vma->vm_private_data = idev;

	mi = uio_find_mem_index(vma);
	if (mi < 0)
		return -EINVAL;

	requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
	actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
	if (requested_pages > actual_pages)
		return -EINVAL;

	if (idev->info->mmap) {
		if (!try_module_get(idev->owner))
			return -ENODEV;
		ret = idev->info->mmap(idev->info, vma);
		module_put(idev->owner);
		return ret;
	}

	switch (idev->info->mem[mi].memtype) {
		case UIO_MEM_PHYS:
			return uio_mmap_physical(vma);
		case UIO_MEM_LOGICAL:
		case UIO_MEM_VIRTUAL:
			return uio_mmap_logical(vma);
		default:
			return -EINVAL;
	}
}

static const struct file_operations uio_fops = {
	.owner		= THIS_MODULE,
	.open		= uio_open,
	.release	= uio_release,
	.read		= uio_read,
	.mmap		= uio_mmap,
	.poll		= uio_poll,
	.fasync		= uio_fasync,
};

static int uio_major_init(void)
{
	uio_major = register_chrdev(0, "uio", &uio_fops);
	if (uio_major < 0)
		return uio_major;
	return 0;
}

static void uio_major_cleanup(void)
{
	unregister_chrdev(uio_major, "uio");
}

static int init_uio_class(void)
{
	int ret = 0;

	if (uio_class != NULL) {
		kref_get(&uio_class->kref);
		goto exit;
	}

	/* This is the first time in here, set everything up properly */
	ret = uio_major_init();
	if (ret)
		goto exit;

	uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL);
	if (!uio_class) {
		ret = -ENOMEM;
		goto err_kzalloc;
	}

	kref_init(&uio_class->kref);
	uio_class->class = class_create(THIS_MODULE, "uio");
	if (IS_ERR(uio_class->class)) {
		ret = IS_ERR(uio_class->class);
		printk(KERN_ERR "class_create failed for uio\n");
		goto err_class_create;
	}
	return 0;

err_class_create:
	kfree(uio_class);
	uio_class = NULL;
err_kzalloc:
	uio_major_cleanup();
exit:
	return ret;
}

static void release_uio_class(struct kref *kref)
{
	/* Ok, we cheat as we know we only have one uio_class */
	class_destroy(uio_class->class);
	kfree(uio_class);
	uio_major_cleanup();
	uio_class = NULL;
}

static void uio_class_destroy(void)
{
	if (uio_class)
		kref_put(&uio_class->kref, release_uio_class);
}

/**
 * uio_register_device - register a new userspace IO device
 * @owner:	module that creates the new device
 * @parent:	parent device
 * @info:	UIO device capabilities
 *
 * returns zero on success or a negative error code.
 */
int __uio_register_device(struct module *owner,
			  struct device *parent,
			  struct uio_info *info)
{
	struct uio_device *idev;
	int ret = 0;

	if (!parent || !info || !info->name || !info->version)
		return -EINVAL;

	info->uio_dev = NULL;

	ret = init_uio_class();
	if (ret)
		return ret;

	idev = kzalloc(sizeof(*idev), GFP_KERNEL);
	if (!idev) {
		ret = -ENOMEM;
		goto err_kzalloc;
	}

	idev->owner = owner;
	idev->info = info;
	init_waitqueue_head(&idev->wait);
	atomic_set(&idev->event, 0);

	ret = uio_get_minor(idev);
	if (ret)
		goto err_get_minor;

	idev->dev = device_create(uio_class->class, parent,
				  MKDEV(uio_major, idev->minor),
				  "uio%d", idev->minor);
	if (IS_ERR(idev->dev)) {
		printk(KERN_ERR "UIO: device register failed\n");
		ret = PTR_ERR(idev->dev);
		goto err_device_create;
	}
	dev_set_drvdata(idev->dev, idev);

	ret = uio_dev_add_attributes(idev);
	if (ret)
		goto err_uio_dev_add_attributes;

	info->uio_dev = idev;

	if (idev->info->irq >= 0) {
		ret = request_irq(idev->info->irq, uio_interrupt,
				  idev->info->irq_flags, idev->info->name, idev);
		if (ret)
			goto err_request_irq;
	}

	return 0;

err_request_irq:
	uio_dev_del_attributes(idev);
err_uio_dev_add_attributes:
	device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
err_device_create:
	uio_free_minor(idev);
err_get_minor:
	kfree(idev);
err_kzalloc:
	uio_class_destroy();
	return ret;
}
EXPORT_SYMBOL_GPL(__uio_register_device);

/**
 * uio_unregister_device - unregister a industrial IO device
 * @info:	UIO device capabilities
 *
 */
void uio_unregister_device(struct uio_info *info)
{
	struct uio_device *idev;

	if (!info || !info->uio_dev)
		return;

	idev = info->uio_dev;

	uio_free_minor(idev);

	if (info->irq >= 0)
		free_irq(info->irq, idev);

	uio_dev_del_attributes(idev);

	dev_set_drvdata(idev->dev, NULL);
	device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
	kfree(idev);
	uio_class_destroy();

	return;
}
EXPORT_SYMBOL_GPL(uio_unregister_device);

static int __init uio_init(void)
{
	return 0;
}

static void __exit uio_exit(void)
{
}

module_init(uio_init)
module_exit(uio_exit)
MODULE_LICENSE("GPL v2");
Commit	Line	Data
beafc54c HK	1	/*
	2	* drivers/uio/uio.c
	3	*
	4	* Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
	5	* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
	6	* Copyright(C) 2006, Hans J. Koch <hjk@linutronix.de>
	7	* Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
	8	*
	9	* Userspace IO
	10	*
	11	* Base Functions
	12	*
	13	* Licensed under the GPLv2 only.
	14	*/
	15
	16	#include <linux/module.h>
	17	#include <linux/init.h>
	18	#include <linux/poll.h>
	19	#include <linux/device.h>
	20	#include <linux/mm.h>
	21	#include <linux/idr.h>
	22	#include <linux/string.h>
	23	#include <linux/kobject.h>
	24	#include <linux/uio_driver.h>
	25
	26	#define UIO_MAX_DEVICES 255
	27
	28	struct uio_device {
	29	struct module *owner;
	30	struct device *dev;
	31	int minor;
	32	atomic_t event;
	33	struct fasync_struct *async_queue;
	34	wait_queue_head_t wait;
	35	int vma_count;
	36	struct uio_info *info;
81e7c6a6	37	struct kobject *map_dir;
beafc54c HK	38	};
	39
	40	static int uio_major;
	41	static DEFINE_IDR(uio_idr);
4f014691	42	static const struct file_operations uio_fops;
beafc54c HK	43
	44	/* UIO class infrastructure */
	45	static struct uio_class {
	46	struct kref kref;
	47	struct class *class;
	48	} *uio_class;
	49
	50	/*
	51	* attributes
	52	*/
	53
81e7c6a6 GKH	54	struct uio_map {
	55	struct kobject kobj;
	56	struct uio_mem *mem;
beafc54c	57	};
81e7c6a6	58	#define to_map(map) container_of(map, struct uio_map, kobj)
beafc54c	59
beafc54c	60
81e7c6a6	61	static ssize_t map_attr_show(struct kobject kobj, struct kobj_attribute attr,
beafc54c HK	62	char *buf)
beafc54c HK	63	{
81e7c6a6 GKH	64	struct uio_map *map = to_map(kobj);
81e7c6a6 GKH	65	struct uio_mem *mem = map->mem;
beafc54c	66
81e7c6a6	67	if (strncmp(attr->attr.name, "addr", 4) == 0)
beafc54c HK	68	return sprintf(buf, "0x%lx\n", mem->addr);
beafc54c HK	69
81e7c6a6	70	if (strncmp(attr->attr.name, "size", 4) == 0)
beafc54c HK	71	return sprintf(buf, "0x%lx\n", mem->size);
	72
	73	return -ENODEV;
	74	}
	75
81e7c6a6 GKH	76	static struct kobj_attribute attr_attribute =
	77	__ATTR(addr, S_IRUGO, map_attr_show, NULL);
	78	static struct kobj_attribute size_attribute =
	79	__ATTR(size, S_IRUGO, map_attr_show, NULL);
beafc54c	80
81e7c6a6 GKH	81	static struct attribute *attrs[] = {
	82	&attr_attribute.attr,
	83	&size_attribute.attr,
	84	NULL, /* need to NULL terminate the list of attributes */
beafc54c HK	85	};
beafc54c HK	86
81e7c6a6 GKH	87	static void map_release(struct kobject *kobj)
	88	{
	89	struct uio_map *map = to_map(kobj);
	90	kfree(map);
	91	}
	92
beafc54c	93	static struct kobj_type map_attr_type = {
81e7c6a6 GKH	94	.release = map_release,
81e7c6a6 GKH	95	.default_attrs = attrs,
beafc54c HK	96	};
	97
	98	static ssize_t show_name(struct device *dev,
	99	struct device_attribute attr, char buf)
	100	{
	101	struct uio_device *idev = dev_get_drvdata(dev);
	102	if (idev)
	103	return sprintf(buf, "%s\n", idev->info->name);
	104	else
	105	return -ENODEV;
	106	}
	107	static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
	108
	109	static ssize_t show_version(struct device *dev,
	110	struct device_attribute attr, char buf)
	111	{
	112	struct uio_device *idev = dev_get_drvdata(dev);
	113	if (idev)
	114	return sprintf(buf, "%s\n", idev->info->version);
	115	else
	116	return -ENODEV;
	117	}
	118	static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
	119
	120	static ssize_t show_event(struct device *dev,
	121	struct device_attribute attr, char buf)
	122	{
	123	struct uio_device *idev = dev_get_drvdata(dev);
	124	if (idev)
	125	return sprintf(buf, "%u\n",
	126	(unsigned int)atomic_read(&idev->event));
	127	else
	128	return -ENODEV;
	129	}
	130	static DEVICE_ATTR(event, S_IRUGO, show_event, NULL);
	131
	132	static struct attribute *uio_attrs[] = {
	133	&dev_attr_name.attr,
	134	&dev_attr_version.attr,
	135	&dev_attr_event.attr,
	136	NULL,
	137	};
	138
	139	static struct attribute_group uio_attr_grp = {
	140	.attrs = uio_attrs,
	141	};
	142
	143	/*
	144	* device functions
	145	*/
	146	static int uio_dev_add_attributes(struct uio_device *idev)
	147	{
	148	int ret;
	149	int mi;
	150	int map_found = 0;
	151	struct uio_mem *mem;
81e7c6a6	152	struct uio_map *map;
beafc54c HK	153
	154	ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp);
	155	if (ret)
	156	goto err_group;
	157
	158	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
	159	mem = &idev->info->mem[mi];
	160	if (mem->size == 0)
	161	break;
	162	if (!map_found) {
	163	map_found = 1;
81e7c6a6 GKH	164	idev->map_dir = kobject_create_and_add("maps",
	165	&idev->dev->kobj);
	166	if (!idev->map_dir)
	167	goto err;
beafc54c	168	}
81e7c6a6 GKH	169	map = kzalloc(sizeof(*map), GFP_KERNEL);
	170	if (!map)
	171	goto err;
f9cb074b	172	kobject_init(&map->kobj, &map_attr_type);
81e7c6a6 GKH	173	map->mem = mem;
81e7c6a6 GKH	174	mem->map = map;
b2d6db58	175	ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
81e7c6a6 GKH	176	if (ret)
	177	goto err;
	178	ret = kobject_uevent(&map->kobj, KOBJ_ADD);
beafc54c	179	if (ret)
81e7c6a6	180	goto err;
beafc54c HK	181	}
	182
	183	return 0;
	184
81e7c6a6	185	err:
beafc54c HK	186	for (mi--; mi>=0; mi--) {
beafc54c HK	187	mem = &idev->info->mem[mi];
81e7c6a6	188	map = mem->map;
c10997f6	189	kobject_put(&map->kobj);
beafc54c	190	}
c10997f6	191	kobject_put(idev->map_dir);
beafc54c HK	192	sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
	193	err_group:
	194	dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
	195	return ret;
	196	}
	197
	198	static void uio_dev_del_attributes(struct uio_device *idev)
	199	{
	200	int mi;
	201	struct uio_mem *mem;
	202	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
	203	mem = &idev->info->mem[mi];
	204	if (mem->size == 0)
	205	break;
c10997f6	206	kobject_put(&mem->map->kobj);
beafc54c	207	}
c10997f6	208	kobject_put(idev->map_dir);
beafc54c HK	209	sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
	210	}
	211
	212	static int uio_get_minor(struct uio_device *idev)
	213	{
	214	static DEFINE_MUTEX(minor_lock);
	215	int retval = -ENOMEM;
	216	int id;
	217
	218	mutex_lock(&minor_lock);
	219	if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0)
	220	goto exit;
	221
	222	retval = idr_get_new(&uio_idr, idev, &id);
	223	if (retval < 0) {
	224	if (retval == -EAGAIN)
	225	retval = -ENOMEM;
	226	goto exit;
	227	}
	228	idev->minor = id & MAX_ID_MASK;
	229	exit:
	230	mutex_unlock(&minor_lock);
	231	return retval;
	232	}
	233
	234	static void uio_free_minor(struct uio_device *idev)
	235	{
	236	idr_remove(&uio_idr, idev->minor);
	237	}
	238
	239	/**
	240	* uio_event_notify - trigger an interrupt event
	241	* @info: UIO device capabilities
	242	*/
	243	void uio_event_notify(struct uio_info *info)
	244	{
	245	struct uio_device *idev = info->uio_dev;
	246
	247	atomic_inc(&idev->event);
	248	wake_up_interruptible(&idev->wait);
	249	kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
	250	}
	251	EXPORT_SYMBOL_GPL(uio_event_notify);
	252
	253	/**
	254	* uio_interrupt - hardware interrupt handler
	255	* @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
	256	* @dev_id: Pointer to the devices uio_device structure
	257	*/
	258	static irqreturn_t uio_interrupt(int irq, void *dev_id)
	259	{
	260	struct uio_device idev = (struct uio_device )dev_id;
	261	irqreturn_t ret = idev->info->handler(irq, idev->info);
	262
	263	if (ret == IRQ_HANDLED)
	264	uio_event_notify(idev->info);
	265
	266	return ret;
	267	}
	268
	269	struct uio_listener {
	270	struct uio_device *dev;
	271	s32 event_count;
	272	};
273
274	static int uio_open(struct inode inode, struct file filep)
275	{
276	struct uio_device *idev;
277	struct uio_listener *listener;
278	int ret = 0;
279
280	idev = idr_find(&uio_idr, iminor(inode));
281	if (!idev)
282	return -ENODEV;
283
284	listener = kmalloc(sizeof(*listener), GFP_KERNEL);
285	if (!listener)
286	return -ENOMEM;
287
288	listener->dev = idev;
289	listener->event_count = atomic_read(&idev->event);
290	filep->private_data = listener;
291
292	if (idev->info->open) {
293	if (!try_module_get(idev->owner))
294	return -ENODEV;
295	ret = idev->info->open(idev->info, inode);
296	module_put(idev->owner);
297	}
298
299	if (ret)
300	kfree(listener);
301
302	return ret;
303	}
304
305	static int uio_fasync(int fd, struct file *filep, int on)
306	{
307	struct uio_listener *listener = filep->private_data;
308	struct uio_device *idev = listener->dev;
309
310	return fasync_helper(fd, filep, on, &idev->async_queue);
311	}
312
313	static int uio_release(struct inode inode, struct file filep)
314	{
315	int ret = 0;
316	struct uio_listener *listener = filep->private_data;
317	struct uio_device *idev = listener->dev;
318
319	if (idev->info->release) {
320	if (!try_module_get(idev->owner))
321	return -ENODEV;
322	ret = idev->info->release(idev->info, inode);
323	module_put(idev->owner);
324	}
325	if (filep->f_flags & FASYNC)
326	ret = uio_fasync(-1, filep, 0);
327	kfree(listener);
328	return ret;
329	}
330
331	static unsigned int uio_poll(struct file filep, poll_table wait)
332	{
333	struct uio_listener *listener = filep->private_data;
334	struct uio_device *idev = listener->dev;
335
336	if (idev->info->irq == UIO_IRQ_NONE)
337	return -EIO;
338
339	poll_wait(filep, &idev->wait, wait);
340	if (listener->event_count != atomic_read(&idev->event))
341	return POLLIN \| POLLRDNORM;
342	return 0;
343	}
344
345	static ssize_t uio_read(struct file filep, char __user buf,
346	size_t count, loff_t *ppos)
347	{
348	struct uio_listener *listener = filep->private_data;
349	struct uio_device *idev = listener->dev;
350	DECLARE_WAITQUEUE(wait, current);
351	ssize_t retval;
352	s32 event_count;
353
354	if (idev->info->irq == UIO_IRQ_NONE)
355	return -EIO;
356
357	if (count != sizeof(s32))
358	return -EINVAL;
359
360	add_wait_queue(&idev->wait, &wait);
361
362	do {
363	set_current_state(TASK_INTERRUPTIBLE);
364
365	event_count = atomic_read(&idev->event);
366	if (event_count != listener->event_count) {
367	if (copy_to_user(buf, &event_count, count))
368	retval = -EFAULT;
369	else {
370	listener->event_count = event_count;
371	retval = count;
372	}
373	break;
374	}
375
376	if (filep->f_flags & O_NONBLOCK) {
377	retval = -EAGAIN;
378	break;
379	}
380
381	if (signal_pending(current)) {
382	retval = -ERESTARTSYS;
383	break;
384	}
385	schedule();
386	} while (1);
387
388	__set_current_state(TASK_RUNNING);
389	remove_wait_queue(&idev->wait, &wait);
390
391	return retval;
392	}
393
394	static int uio_find_mem_index(struct vm_area_struct *vma)
395	{
396	int mi;
397	struct uio_device *idev = vma->vm_private_data;
398
399	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
400	if (idev->info->mem[mi].size == 0)
401	return -1;
402	if (vma->vm_pgoff == mi)
403	return mi;
404	}
405	return -1;
406	}
407
408	static void uio_vma_open(struct vm_area_struct *vma)
409	{
410	struct uio_device *idev = vma->vm_private_data;
411	idev->vma_count++;
412	}
413
414	static void uio_vma_close(struct vm_area_struct *vma)
415	{
416	struct uio_device *idev = vma->vm_private_data;
417	idev->vma_count--;
418	}
419
a18b630d	420	static int uio_vma_fault(struct vm_area_struct vma, struct vm_fault vmf)
beafc54c HK	421	{
beafc54c HK	422	struct uio_device *idev = vma->vm_private_data;
a18b630d	423	struct page *page;
beafc54c HK	424
	425	int mi = uio_find_mem_index(vma);
	426	if (mi < 0)
a18b630d	427	return VM_FAULT_SIGBUS;
beafc54c HK	428
	429	if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
	430	page = virt_to_page(idev->info->mem[mi].addr);
	431	else
	432	page = vmalloc_to_page((void*)idev->info->mem[mi].addr);
	433	get_page(page);
a18b630d NP	434	vmf->page = page;
a18b630d NP	435	return 0;
beafc54c HK	436	}
	437
	438	static struct vm_operations_struct uio_vm_ops = {
	439	.open = uio_vma_open,
	440	.close = uio_vma_close,
a18b630d	441	.fault = uio_vma_fault,
beafc54c HK	442	};
	443
	444	static int uio_mmap_physical(struct vm_area_struct *vma)
	445	{
	446	struct uio_device *idev = vma->vm_private_data;
	447	int mi = uio_find_mem_index(vma);
	448	if (mi < 0)
	449	return -EINVAL;
	450
	451	vma->vm_flags \|= VM_IO \| VM_RESERVED;
	452
	453	return remap_pfn_range(vma,
	454	vma->vm_start,
	455	idev->info->mem[mi].addr >> PAGE_SHIFT,
	456	vma->vm_end - vma->vm_start,
	457	vma->vm_page_prot);
	458	}
	459
	460	static int uio_mmap_logical(struct vm_area_struct *vma)
	461	{
	462	vma->vm_flags \|= VM_RESERVED;
	463	vma->vm_ops = &uio_vm_ops;
	464	uio_vma_open(vma);
	465	return 0;
	466	}
	467
	468	static int uio_mmap(struct file filep, struct vm_area_struct vma)
	469	{
	470	struct uio_listener *listener = filep->private_data;
	471	struct uio_device *idev = listener->dev;
	472	int mi;
	473	unsigned long requested_pages, actual_pages;
	474	int ret = 0;
	475
	476	if (vma->vm_end < vma->vm_start)
	477	return -EINVAL;
	478
	479	vma->vm_private_data = idev;
	480
	481	mi = uio_find_mem_index(vma);
	482	if (mi < 0)
	483	return -EINVAL;
	484
	485	requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
	486	actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
	487	if (requested_pages > actual_pages)
	488	return -EINVAL;
	489
	490	if (idev->info->mmap) {
	491	if (!try_module_get(idev->owner))
	492	return -ENODEV;
	493	ret = idev->info->mmap(idev->info, vma);
	494	module_put(idev->owner);
	495	return ret;
	496	}
	497
	498	switch (idev->info->mem[mi].memtype) {
	499	case UIO_MEM_PHYS:
	500	return uio_mmap_physical(vma);
	501	case UIO_MEM_LOGICAL:
	502	case UIO_MEM_VIRTUAL:
	503	return uio_mmap_logical(vma);
	504	default:
	505	return -EINVAL;
506	}
507	}
508
4f014691	509	static const struct file_operations uio_fops = {
beafc54c HK	510	.owner = THIS_MODULE,
	511	.open = uio_open,
	512	.release = uio_release,
	513	.read = uio_read,
	514	.mmap = uio_mmap,
	515	.poll = uio_poll,
	516	.fasync = uio_fasync,
	517	};
	518
	519	static int uio_major_init(void)
	520	{
	521	uio_major = register_chrdev(0, "uio", &uio_fops);
	522	if (uio_major < 0)
	523	return uio_major;
	524	return 0;
	525	}
	526
	527	static void uio_major_cleanup(void)
	528	{
	529	unregister_chrdev(uio_major, "uio");
	530	}
	531
	532	static int init_uio_class(void)
	533	{
	534	int ret = 0;
	535
	536	if (uio_class != NULL) {
	537	kref_get(&uio_class->kref);
	538	goto exit;
	539	}
	540
	541	/* This is the first time in here, set everything up properly */
	542	ret = uio_major_init();
	543	if (ret)
	544	goto exit;
	545
	546	uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL);
	547	if (!uio_class) {
	548	ret = -ENOMEM;
	549	goto err_kzalloc;
	550	}
	551
	552	kref_init(&uio_class->kref);
	553	uio_class->class = class_create(THIS_MODULE, "uio");
	554	if (IS_ERR(uio_class->class)) {
	555	ret = IS_ERR(uio_class->class);
	556	printk(KERN_ERR "class_create failed for uio\n");
	557	goto err_class_create;
	558	}
	559	return 0;
	560
	561	err_class_create:
	562	kfree(uio_class);
	563	uio_class = NULL;
	564	err_kzalloc:
	565	uio_major_cleanup();
	566	exit:
	567	return ret;
	568	}
	569
	570	static void release_uio_class(struct kref *kref)
	571	{
	572	/* Ok, we cheat as we know we only have one uio_class */
	573	class_destroy(uio_class->class);
574	kfree(uio_class);
575	uio_major_cleanup();
576	uio_class = NULL;
577	}
578
579	static void uio_class_destroy(void)
580	{
581	if (uio_class)
582	kref_put(&uio_class->kref, release_uio_class);
583	}
584
585	/**
586	* uio_register_device - register a new userspace IO device
587	* @owner: module that creates the new device
588	* @parent: parent device
589	* @info: UIO device capabilities
590	*
591	* returns zero on success or a negative error code.
592	*/
593	int __uio_register_device(struct module *owner,
594	struct device *parent,
595	struct uio_info *info)
596	{
597	struct uio_device *idev;
598	int ret = 0;
599
600	if (!parent \|\| !info \|\| !info->name \|\| !info->version)
601	return -EINVAL;
602
603	info->uio_dev = NULL;
604
605	ret = init_uio_class();
606	if (ret)
607	return ret;
608
609	idev = kzalloc(sizeof(*idev), GFP_KERNEL);
610	if (!idev) {
611	ret = -ENOMEM;
612	goto err_kzalloc;
613	}
614
615	idev->owner = owner;
616	idev->info = info;
617	init_waitqueue_head(&idev->wait);
618	atomic_set(&idev->event, 0);
619
620	ret = uio_get_minor(idev);
621	if (ret)
622	goto err_get_minor;
623
624	idev->dev = device_create(uio_class->class, parent,
625	MKDEV(uio_major, idev->minor),
626	"uio%d", idev->minor);
627	if (IS_ERR(idev->dev)) {
628	printk(KERN_ERR "UIO: device register failed\n");
629	ret = PTR_ERR(idev->dev);
630	goto err_device_create;
631	}
632	dev_set_drvdata(idev->dev, idev);
633
634	ret = uio_dev_add_attributes(idev);
635	if (ret)
636	goto err_uio_dev_add_attributes;
637
638	info->uio_dev = idev;
639
640	if (idev->info->irq >= 0) {
641	ret = request_irq(idev->info->irq, uio_interrupt,
642	idev->info->irq_flags, idev->info->name, idev);
643	if (ret)
644	goto err_request_irq;
645	}
646
647	return 0;
648
649	err_request_irq:
650	uio_dev_del_attributes(idev);
651	err_uio_dev_add_attributes:
652	device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
653	err_device_create:
654	uio_free_minor(idev);
655	err_get_minor:
656	kfree(idev);
657	err_kzalloc:
658	uio_class_destroy();
659	return ret;
660	}
661	EXPORT_SYMBOL_GPL(__uio_register_device);
662
663	/**
664	* uio_unregister_device - unregister a industrial IO device
665	* @info: UIO device capabilities
666	*
667	*/
668	void uio_unregister_device(struct uio_info *info)
669	{
670	struct uio_device *idev;
671
672	if (!info \|\| !info->uio_dev)
673	return;
674
675	idev = info->uio_dev;
676
677	uio_free_minor(idev);
678
679	if (info->irq >= 0)
680	free_irq(info->irq, idev);
681
682	uio_dev_del_attributes(idev);
683
684	dev_set_drvdata(idev->dev, NULL);
685	device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
686	kfree(idev);
687	uio_class_destroy();
688
689	return;
690	}
691	EXPORT_SYMBOL_GPL(uio_unregister_device);
692
693	static int __init uio_init(void)
694	{
695	return 0;
696	}
697
698	static void __exit uio_exit(void)
699	{
700	}
701
702	module_init(uio_init)
703	module_exit(uio_exit)
704	MODULE_LICENSE("GPL v2");