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- // SPDX-License-Identifier: GPL-2.0
- /*
- * drivers/uio/uio.c
- *
- * Copyright(C) 2005, Benedikt Spranger <[email protected]>
- * Copyright(C) 2005, Thomas Gleixner <[email protected]>
- * Copyright(C) 2006, Hans J. Koch <[email protected]>
- * Copyright(C) 2006, Greg Kroah-Hartman <[email protected]>
- *
- * Userspace IO
- *
- * Base Functions
- */
- #include <linux/module.h>
- #include <linux/init.h>
- #include <linux/poll.h>
- #include <linux/device.h>
- #include <linux/slab.h>
- #include <linux/mm.h>
- #include <linux/idr.h>
- #include <linux/sched/signal.h>
- #include <linux/string.h>
- #include <linux/kobject.h>
- #include <linux/cdev.h>
- #include <linux/uio_driver.h>
- #define UIO_MAX_DEVICES (1U << MINORBITS)
- static int uio_major;
- static struct cdev *uio_cdev;
- static DEFINE_IDR(uio_idr);
- static const struct file_operations uio_fops;
- /* Protect idr accesses */
- static DEFINE_MUTEX(minor_lock);
- /*
- * 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_name_show(struct uio_mem *mem, char *buf)
- {
- if (unlikely(!mem->name))
- mem->name = "";
- return sprintf(buf, "%s\n", mem->name);
- }
- static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
- {
- return sprintf(buf, "%pa\n", &mem->addr);
- }
- static ssize_t map_size_show(struct uio_mem *mem, char *buf)
- {
- return sprintf(buf, "%pa\n", &mem->size);
- }
- static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
- {
- return sprintf(buf, "0x%llx\n", (unsigned long long)mem->offs);
- }
- struct map_sysfs_entry {
- struct attribute attr;
- ssize_t (*show)(struct uio_mem *, char *);
- ssize_t (*store)(struct uio_mem *, const char *, size_t);
- };
- static struct map_sysfs_entry name_attribute =
- __ATTR(name, S_IRUGO, map_name_show, NULL);
- static struct map_sysfs_entry addr_attribute =
- __ATTR(addr, S_IRUGO, map_addr_show, NULL);
- static struct map_sysfs_entry size_attribute =
- __ATTR(size, S_IRUGO, map_size_show, NULL);
- static struct map_sysfs_entry offset_attribute =
- __ATTR(offset, S_IRUGO, map_offset_show, NULL);
- static struct attribute *map_attrs[] = {
- &name_attribute.attr,
- &addr_attribute.attr,
- &size_attribute.attr,
- &offset_attribute.attr,
- NULL, /* need to NULL terminate the list of attributes */
- };
- ATTRIBUTE_GROUPS(map);
- static void map_release(struct kobject *kobj)
- {
- struct uio_map *map = to_map(kobj);
- kfree(map);
- }
- static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
- char *buf)
- {
- struct uio_map *map = to_map(kobj);
- struct uio_mem *mem = map->mem;
- struct map_sysfs_entry *entry;
- entry = container_of(attr, struct map_sysfs_entry, attr);
- if (!entry->show)
- return -EIO;
- return entry->show(mem, buf);
- }
- static const struct sysfs_ops map_sysfs_ops = {
- .show = map_type_show,
- };
- static struct kobj_type map_attr_type = {
- .release = map_release,
- .sysfs_ops = &map_sysfs_ops,
- .default_groups = map_groups,
- };
- struct uio_portio {
- struct kobject kobj;
- struct uio_port *port;
- };
- #define to_portio(portio) container_of(portio, struct uio_portio, kobj)
- static ssize_t portio_name_show(struct uio_port *port, char *buf)
- {
- if (unlikely(!port->name))
- port->name = "";
- return sprintf(buf, "%s\n", port->name);
- }
- static ssize_t portio_start_show(struct uio_port *port, char *buf)
- {
- return sprintf(buf, "0x%lx\n", port->start);
- }
- static ssize_t portio_size_show(struct uio_port *port, char *buf)
- {
- return sprintf(buf, "0x%lx\n", port->size);
- }
- static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
- {
- const char *porttypes[] = {"none", "x86", "gpio", "other"};
- if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
- return -EINVAL;
- return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
- }
- struct portio_sysfs_entry {
- struct attribute attr;
- ssize_t (*show)(struct uio_port *, char *);
- ssize_t (*store)(struct uio_port *, const char *, size_t);
- };
- static struct portio_sysfs_entry portio_name_attribute =
- __ATTR(name, S_IRUGO, portio_name_show, NULL);
- static struct portio_sysfs_entry portio_start_attribute =
- __ATTR(start, S_IRUGO, portio_start_show, NULL);
- static struct portio_sysfs_entry portio_size_attribute =
- __ATTR(size, S_IRUGO, portio_size_show, NULL);
- static struct portio_sysfs_entry portio_porttype_attribute =
- __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
- static struct attribute *portio_attrs[] = {
- &portio_name_attribute.attr,
- &portio_start_attribute.attr,
- &portio_size_attribute.attr,
- &portio_porttype_attribute.attr,
- NULL,
- };
- ATTRIBUTE_GROUPS(portio);
- static void portio_release(struct kobject *kobj)
- {
- struct uio_portio *portio = to_portio(kobj);
- kfree(portio);
- }
- static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
- char *buf)
- {
- struct uio_portio *portio = to_portio(kobj);
- struct uio_port *port = portio->port;
- struct portio_sysfs_entry *entry;
- entry = container_of(attr, struct portio_sysfs_entry, attr);
- if (!entry->show)
- return -EIO;
- return entry->show(port, buf);
- }
- static const struct sysfs_ops portio_sysfs_ops = {
- .show = portio_type_show,
- };
- static struct kobj_type portio_attr_type = {
- .release = portio_release,
- .sysfs_ops = &portio_sysfs_ops,
- .default_groups = portio_groups,
- };
- static ssize_t name_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct uio_device *idev = dev_get_drvdata(dev);
- int ret;
- mutex_lock(&idev->info_lock);
- if (!idev->info) {
- ret = -EINVAL;
- dev_err(dev, "the device has been unregistered\n");
- goto out;
- }
- ret = sprintf(buf, "%s\n", idev->info->name);
- out:
- mutex_unlock(&idev->info_lock);
- return ret;
- }
- static DEVICE_ATTR_RO(name);
- static ssize_t version_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct uio_device *idev = dev_get_drvdata(dev);
- int ret;
- mutex_lock(&idev->info_lock);
- if (!idev->info) {
- ret = -EINVAL;
- dev_err(dev, "the device has been unregistered\n");
- goto out;
- }
- ret = sprintf(buf, "%s\n", idev->info->version);
- out:
- mutex_unlock(&idev->info_lock);
- return ret;
- }
- static DEVICE_ATTR_RO(version);
- static ssize_t event_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct uio_device *idev = dev_get_drvdata(dev);
- return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
- }
- static DEVICE_ATTR_RO(event);
- static struct attribute *uio_attrs[] = {
- &dev_attr_name.attr,
- &dev_attr_version.attr,
- &dev_attr_event.attr,
- NULL,
- };
- ATTRIBUTE_GROUPS(uio);
- /* UIO class infrastructure */
- static struct class uio_class = {
- .name = "uio",
- .dev_groups = uio_groups,
- };
- static bool uio_class_registered;
- /*
- * device functions
- */
- static int uio_dev_add_attributes(struct uio_device *idev)
- {
- int ret;
- int mi, pi;
- int map_found = 0;
- int portio_found = 0;
- struct uio_mem *mem;
- struct uio_map *map;
- struct uio_port *port;
- struct uio_portio *portio;
- 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) {
- ret = -ENOMEM;
- goto err_map;
- }
- }
- map = kzalloc(sizeof(*map), GFP_KERNEL);
- if (!map) {
- ret = -ENOMEM;
- goto err_map;
- }
- 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_map_kobj;
- ret = kobject_uevent(&map->kobj, KOBJ_ADD);
- if (ret)
- goto err_map_kobj;
- }
- for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
- port = &idev->info->port[pi];
- if (port->size == 0)
- break;
- if (!portio_found) {
- portio_found = 1;
- idev->portio_dir = kobject_create_and_add("portio",
- &idev->dev.kobj);
- if (!idev->portio_dir) {
- ret = -ENOMEM;
- goto err_portio;
- }
- }
- portio = kzalloc(sizeof(*portio), GFP_KERNEL);
- if (!portio) {
- ret = -ENOMEM;
- goto err_portio;
- }
- kobject_init(&portio->kobj, &portio_attr_type);
- portio->port = port;
- port->portio = portio;
- ret = kobject_add(&portio->kobj, idev->portio_dir,
- "port%d", pi);
- if (ret)
- goto err_portio_kobj;
- ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
- if (ret)
- goto err_portio_kobj;
- }
- return 0;
- err_portio:
- pi--;
- err_portio_kobj:
- for (; pi >= 0; pi--) {
- port = &idev->info->port[pi];
- portio = port->portio;
- kobject_put(&portio->kobj);
- }
- kobject_put(idev->portio_dir);
- err_map:
- mi--;
- err_map_kobj:
- for (; mi >= 0; mi--) {
- mem = &idev->info->mem[mi];
- map = mem->map;
- kobject_put(&map->kobj);
- }
- kobject_put(idev->map_dir);
- dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret);
- return ret;
- }
- static void uio_dev_del_attributes(struct uio_device *idev)
- {
- int i;
- struct uio_mem *mem;
- struct uio_port *port;
- for (i = 0; i < MAX_UIO_MAPS; i++) {
- mem = &idev->info->mem[i];
- if (mem->size == 0)
- break;
- kobject_put(&mem->map->kobj);
- }
- kobject_put(idev->map_dir);
- for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
- port = &idev->info->port[i];
- if (port->size == 0)
- break;
- kobject_put(&port->portio->kobj);
- }
- kobject_put(idev->portio_dir);
- }
- static int uio_get_minor(struct uio_device *idev)
- {
- int retval;
- mutex_lock(&minor_lock);
- retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
- if (retval >= 0) {
- idev->minor = retval;
- retval = 0;
- } else if (retval == -ENOSPC) {
- dev_err(&idev->dev, "too many uio devices\n");
- retval = -EINVAL;
- }
- mutex_unlock(&minor_lock);
- return retval;
- }
- static void uio_free_minor(unsigned long minor)
- {
- mutex_lock(&minor_lock);
- idr_remove(&uio_idr, minor);
- mutex_unlock(&minor_lock);
- }
- /**
- * 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;
- 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;
- mutex_lock(&minor_lock);
- idev = idr_find(&uio_idr, iminor(inode));
- mutex_unlock(&minor_lock);
- if (!idev) {
- ret = -ENODEV;
- goto out;
- }
- get_device(&idev->dev);
- if (!try_module_get(idev->owner)) {
- ret = -ENODEV;
- goto err_module_get;
- }
- listener = kmalloc(sizeof(*listener), GFP_KERNEL);
- if (!listener) {
- ret = -ENOMEM;
- goto err_alloc_listener;
- }
- listener->dev = idev;
- listener->event_count = atomic_read(&idev->event);
- filep->private_data = listener;
- mutex_lock(&idev->info_lock);
- if (!idev->info) {
- mutex_unlock(&idev->info_lock);
- ret = -EINVAL;
- goto err_infoopen;
- }
- if (idev->info->open)
- ret = idev->info->open(idev->info, inode);
- mutex_unlock(&idev->info_lock);
- if (ret)
- goto err_infoopen;
- return 0;
- err_infoopen:
- kfree(listener);
- err_alloc_listener:
- module_put(idev->owner);
- err_module_get:
- put_device(&idev->dev);
- out:
- 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;
- mutex_lock(&idev->info_lock);
- if (idev->info && idev->info->release)
- ret = idev->info->release(idev->info, inode);
- mutex_unlock(&idev->info_lock);
- module_put(idev->owner);
- kfree(listener);
- put_device(&idev->dev);
- return ret;
- }
- static __poll_t uio_poll(struct file *filep, poll_table *wait)
- {
- struct uio_listener *listener = filep->private_data;
- struct uio_device *idev = listener->dev;
- __poll_t ret = 0;
- mutex_lock(&idev->info_lock);
- if (!idev->info || !idev->info->irq)
- ret = -EIO;
- mutex_unlock(&idev->info_lock);
- if (ret)
- return ret;
- poll_wait(filep, &idev->wait, wait);
- if (listener->event_count != atomic_read(&idev->event))
- return EPOLLIN | EPOLLRDNORM;
- 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 = 0;
- s32 event_count;
- if (count != sizeof(s32))
- return -EINVAL;
- add_wait_queue(&idev->wait, &wait);
- do {
- mutex_lock(&idev->info_lock);
- if (!idev->info || !idev->info->irq) {
- retval = -EIO;
- mutex_unlock(&idev->info_lock);
- break;
- }
- mutex_unlock(&idev->info_lock);
- set_current_state(TASK_INTERRUPTIBLE);
- event_count = atomic_read(&idev->event);
- if (event_count != listener->event_count) {
- __set_current_state(TASK_RUNNING);
- 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 ssize_t uio_write(struct file *filep, const char __user *buf,
- size_t count, loff_t *ppos)
- {
- struct uio_listener *listener = filep->private_data;
- struct uio_device *idev = listener->dev;
- ssize_t retval;
- s32 irq_on;
- if (count != sizeof(s32))
- return -EINVAL;
- if (copy_from_user(&irq_on, buf, count))
- return -EFAULT;
- mutex_lock(&idev->info_lock);
- if (!idev->info) {
- retval = -EINVAL;
- goto out;
- }
- if (!idev->info->irq) {
- retval = -EIO;
- goto out;
- }
- if (!idev->info->irqcontrol) {
- retval = -ENOSYS;
- goto out;
- }
- retval = idev->info->irqcontrol(idev->info, irq_on);
- out:
- mutex_unlock(&idev->info_lock);
- return retval ? retval : sizeof(s32);
- }
- static int uio_find_mem_index(struct vm_area_struct *vma)
- {
- struct uio_device *idev = vma->vm_private_data;
- if (vma->vm_pgoff < MAX_UIO_MAPS) {
- if (idev->info->mem[vma->vm_pgoff].size == 0)
- return -1;
- return (int)vma->vm_pgoff;
- }
- return -1;
- }
- static vm_fault_t uio_vma_fault(struct vm_fault *vmf)
- {
- struct uio_device *idev = vmf->vma->vm_private_data;
- struct page *page;
- unsigned long offset;
- void *addr;
- vm_fault_t ret = 0;
- int mi;
- mutex_lock(&idev->info_lock);
- if (!idev->info) {
- ret = VM_FAULT_SIGBUS;
- goto out;
- }
- mi = uio_find_mem_index(vmf->vma);
- if (mi < 0) {
- ret = VM_FAULT_SIGBUS;
- goto out;
- }
- /*
- * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
- * to use mem[N].
- */
- offset = (vmf->pgoff - mi) << PAGE_SHIFT;
- addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
- if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
- page = virt_to_page(addr);
- else
- page = vmalloc_to_page(addr);
- get_page(page);
- vmf->page = page;
- out:
- mutex_unlock(&idev->info_lock);
- return ret;
- }
- static const struct vm_operations_struct uio_logical_vm_ops = {
- .fault = uio_vma_fault,
- };
- static int uio_mmap_logical(struct vm_area_struct *vma)
- {
- vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
- vma->vm_ops = &uio_logical_vm_ops;
- return 0;
- }
- static const struct vm_operations_struct uio_physical_vm_ops = {
- #ifdef CONFIG_HAVE_IOREMAP_PROT
- .access = generic_access_phys,
- #endif
- };
- 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);
- struct uio_mem *mem;
- if (mi < 0)
- return -EINVAL;
- mem = idev->info->mem + mi;
- if (mem->addr & ~PAGE_MASK)
- return -ENODEV;
- if (vma->vm_end - vma->vm_start > mem->size)
- return -EINVAL;
- vma->vm_ops = &uio_physical_vm_ops;
- if (idev->info->mem[mi].memtype == UIO_MEM_PHYS)
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- /*
- * We cannot use the vm_iomap_memory() helper here,
- * because vma->vm_pgoff is the map index we looked
- * up above in uio_find_mem_index(), rather than an
- * actual page offset into the mmap.
- *
- * So we just do the physical mmap without a page
- * offset.
- */
- return remap_pfn_range(vma,
- vma->vm_start,
- mem->addr >> PAGE_SHIFT,
- vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
- }
- 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;
- mutex_lock(&idev->info_lock);
- if (!idev->info) {
- ret = -EINVAL;
- goto out;
- }
- mi = uio_find_mem_index(vma);
- if (mi < 0) {
- ret = -EINVAL;
- goto out;
- }
- requested_pages = vma_pages(vma);
- actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
- + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
- if (requested_pages > actual_pages) {
- ret = -EINVAL;
- goto out;
- }
- if (idev->info->mmap) {
- ret = idev->info->mmap(idev->info, vma);
- goto out;
- }
- switch (idev->info->mem[mi].memtype) {
- case UIO_MEM_IOVA:
- case UIO_MEM_PHYS:
- ret = uio_mmap_physical(vma);
- break;
- case UIO_MEM_LOGICAL:
- case UIO_MEM_VIRTUAL:
- ret = uio_mmap_logical(vma);
- break;
- default:
- ret = -EINVAL;
- }
- out:
- mutex_unlock(&idev->info_lock);
- return ret;
- }
- static const struct file_operations uio_fops = {
- .owner = THIS_MODULE,
- .open = uio_open,
- .release = uio_release,
- .read = uio_read,
- .write = uio_write,
- .mmap = uio_mmap,
- .poll = uio_poll,
- .fasync = uio_fasync,
- .llseek = noop_llseek,
- };
- static int uio_major_init(void)
- {
- static const char name[] = "uio";
- struct cdev *cdev = NULL;
- dev_t uio_dev = 0;
- int result;
- result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
- if (result)
- goto out;
- result = -ENOMEM;
- cdev = cdev_alloc();
- if (!cdev)
- goto out_unregister;
- cdev->owner = THIS_MODULE;
- cdev->ops = &uio_fops;
- kobject_set_name(&cdev->kobj, "%s", name);
- result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
- if (result)
- goto out_put;
- uio_major = MAJOR(uio_dev);
- uio_cdev = cdev;
- return 0;
- out_put:
- kobject_put(&cdev->kobj);
- out_unregister:
- unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
- out:
- return result;
- }
- static void uio_major_cleanup(void)
- {
- unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
- cdev_del(uio_cdev);
- }
- static int init_uio_class(void)
- {
- int ret;
- /* This is the first time in here, set everything up properly */
- ret = uio_major_init();
- if (ret)
- goto exit;
- ret = class_register(&uio_class);
- if (ret) {
- printk(KERN_ERR "class_register failed for uio\n");
- goto err_class_register;
- }
- uio_class_registered = true;
- return 0;
- err_class_register:
- uio_major_cleanup();
- exit:
- return ret;
- }
- static void release_uio_class(void)
- {
- uio_class_registered = false;
- class_unregister(&uio_class);
- uio_major_cleanup();
- }
- static void uio_device_release(struct device *dev)
- {
- struct uio_device *idev = dev_get_drvdata(dev);
- kfree(idev);
- }
- /**
- * __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 (!uio_class_registered)
- return -EPROBE_DEFER;
- if (!parent || !info || !info->name || !info->version)
- return -EINVAL;
- info->uio_dev = NULL;
- idev = kzalloc(sizeof(*idev), GFP_KERNEL);
- if (!idev) {
- return -ENOMEM;
- }
- idev->owner = owner;
- idev->info = info;
- mutex_init(&idev->info_lock);
- init_waitqueue_head(&idev->wait);
- atomic_set(&idev->event, 0);
- ret = uio_get_minor(idev);
- if (ret) {
- kfree(idev);
- return ret;
- }
- device_initialize(&idev->dev);
- idev->dev.devt = MKDEV(uio_major, idev->minor);
- idev->dev.class = &uio_class;
- idev->dev.parent = parent;
- idev->dev.release = uio_device_release;
- dev_set_drvdata(&idev->dev, idev);
- ret = dev_set_name(&idev->dev, "uio%d", idev->minor);
- if (ret)
- goto err_device_create;
- ret = device_add(&idev->dev);
- if (ret)
- goto err_device_create;
- ret = uio_dev_add_attributes(idev);
- if (ret)
- goto err_uio_dev_add_attributes;
- info->uio_dev = idev;
- if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
- /*
- * Note that we deliberately don't use devm_request_irq
- * here. The parent module can unregister the UIO device
- * and call pci_disable_msi, which requires that this
- * irq has been freed. However, the device may have open
- * FDs at the time of unregister and therefore may not be
- * freed until they are released.
- */
- ret = request_irq(info->irq, uio_interrupt,
- info->irq_flags, info->name, idev);
- if (ret) {
- info->uio_dev = NULL;
- goto err_request_irq;
- }
- }
- return 0;
- err_request_irq:
- uio_dev_del_attributes(idev);
- err_uio_dev_add_attributes:
- device_del(&idev->dev);
- err_device_create:
- uio_free_minor(idev->minor);
- put_device(&idev->dev);
- return ret;
- }
- EXPORT_SYMBOL_GPL(__uio_register_device);
- static void devm_uio_unregister_device(struct device *dev, void *res)
- {
- uio_unregister_device(*(struct uio_info **)res);
- }
- /**
- * __devm_uio_register_device - Resource managed uio_register_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 __devm_uio_register_device(struct module *owner,
- struct device *parent,
- struct uio_info *info)
- {
- struct uio_info **ptr;
- int ret;
- ptr = devres_alloc(devm_uio_unregister_device, sizeof(*ptr),
- GFP_KERNEL);
- if (!ptr)
- return -ENOMEM;
- *ptr = info;
- ret = __uio_register_device(owner, parent, info);
- if (ret) {
- devres_free(ptr);
- return ret;
- }
- devres_add(parent, ptr);
- return 0;
- }
- EXPORT_SYMBOL_GPL(__devm_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;
- unsigned long minor;
- if (!info || !info->uio_dev)
- return;
- idev = info->uio_dev;
- minor = idev->minor;
- mutex_lock(&idev->info_lock);
- uio_dev_del_attributes(idev);
- if (info->irq && info->irq != UIO_IRQ_CUSTOM)
- free_irq(info->irq, idev);
- idev->info = NULL;
- mutex_unlock(&idev->info_lock);
- wake_up_interruptible(&idev->wait);
- kill_fasync(&idev->async_queue, SIGIO, POLL_HUP);
- device_unregister(&idev->dev);
- uio_free_minor(minor);
- return;
- }
- EXPORT_SYMBOL_GPL(uio_unregister_device);
- static int __init uio_init(void)
- {
- return init_uio_class();
- }
- static void __exit uio_exit(void)
- {
- release_uio_class();
- idr_destroy(&uio_idr);
- }
- module_init(uio_init)
- module_exit(uio_exit)
- MODULE_LICENSE("GPL v2");
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