v4.19.13 snapshot.
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
new file mode 100644
index 0000000..2762148
--- /dev/null
+++ b/drivers/uio/uio.c
@@ -0,0 +1,1037 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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@hansjkoch.de>
+ * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
+ *
+ * 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 *attrs[] = {
+ &name_attribute.attr,
+ &addr_attribute.attr,
+ &size_attribute.attr,
+ &offset_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 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_attrs = attrs,
+};
+
+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,
+};
+
+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_attrs = portio_attrs,
+};
+
+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,
+};
+
+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 = -ENOMEM;
+
+ 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(struct uio_device *idev)
+{
+ mutex_lock(&minor_lock);
+ idr_remove(&uio_idr, idev->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_alloc_listener;
+ }
+
+ if (idev->info && 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;
+
+ mutex_lock(&idev->info_lock);
+ if (!idev->info || !idev->info->irq)
+ retval = -EIO;
+ mutex_unlock(&idev->info_lock);
+
+ if (retval)
+ return retval;
+
+ 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) {
+ __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 || !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;
+ int 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)
+{
+ vma->vm_flags |= 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;
+ 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_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)
+ return ret;
+
+ 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_register(&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_unregister(&idev->dev);
+err_device_create:
+ uio_free_minor(idev);
+ 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);
+
+ 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);
+
+ device_unregister(&idev->dev);
+
+ 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");