1 // SPDX-License-Identifier: GPL-2.0
5 * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
6 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
7 * Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de>
8 * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/poll.h>
18 #include <linux/device.h>
19 #include <linux/slab.h>
21 #include <linux/idr.h>
22 #include <linux/sched/signal.h>
23 #include <linux/string.h>
24 #include <linux/kobject.h>
25 #include <linux/cdev.h>
26 #include <linux/uio_driver.h>
28 #define UIO_MAX_DEVICES (1U << MINORBITS)
31 static struct cdev *uio_cdev;
32 static DEFINE_IDR(uio_idr);
33 static const struct file_operations uio_fops;
35 /* Protect idr accesses */
36 static DEFINE_MUTEX(minor_lock);
46 #define to_map(map) container_of(map, struct uio_map, kobj)
48 static ssize_t map_name_show(struct uio_mem *mem, char *buf)
50 if (unlikely(!mem->name))
53 return sprintf(buf, "%s\n", mem->name);
56 static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
58 return sprintf(buf, "%pa\n", &mem->addr);
61 static ssize_t map_size_show(struct uio_mem *mem, char *buf)
63 return sprintf(buf, "%pa\n", &mem->size);
66 static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
68 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->offs);
71 struct map_sysfs_entry {
72 struct attribute attr;
73 ssize_t (*show)(struct uio_mem *, char *);
74 ssize_t (*store)(struct uio_mem *, const char *, size_t);
77 static struct map_sysfs_entry name_attribute =
78 __ATTR(name, S_IRUGO, map_name_show, NULL);
79 static struct map_sysfs_entry addr_attribute =
80 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
81 static struct map_sysfs_entry size_attribute =
82 __ATTR(size, S_IRUGO, map_size_show, NULL);
83 static struct map_sysfs_entry offset_attribute =
84 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
86 static struct attribute *attrs[] = {
90 &offset_attribute.attr,
91 NULL, /* need to NULL terminate the list of attributes */
94 static void map_release(struct kobject *kobj)
96 struct uio_map *map = to_map(kobj);
100 static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
103 struct uio_map *map = to_map(kobj);
104 struct uio_mem *mem = map->mem;
105 struct map_sysfs_entry *entry;
107 entry = container_of(attr, struct map_sysfs_entry, attr);
112 return entry->show(mem, buf);
115 static const struct sysfs_ops map_sysfs_ops = {
116 .show = map_type_show,
119 static struct kobj_type map_attr_type = {
120 .release = map_release,
121 .sysfs_ops = &map_sysfs_ops,
122 .default_attrs = attrs,
127 struct uio_port *port;
129 #define to_portio(portio) container_of(portio, struct uio_portio, kobj)
131 static ssize_t portio_name_show(struct uio_port *port, char *buf)
133 if (unlikely(!port->name))
136 return sprintf(buf, "%s\n", port->name);
139 static ssize_t portio_start_show(struct uio_port *port, char *buf)
141 return sprintf(buf, "0x%lx\n", port->start);
144 static ssize_t portio_size_show(struct uio_port *port, char *buf)
146 return sprintf(buf, "0x%lx\n", port->size);
149 static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
151 const char *porttypes[] = {"none", "x86", "gpio", "other"};
153 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
156 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
159 struct portio_sysfs_entry {
160 struct attribute attr;
161 ssize_t (*show)(struct uio_port *, char *);
162 ssize_t (*store)(struct uio_port *, const char *, size_t);
165 static struct portio_sysfs_entry portio_name_attribute =
166 __ATTR(name, S_IRUGO, portio_name_show, NULL);
167 static struct portio_sysfs_entry portio_start_attribute =
168 __ATTR(start, S_IRUGO, portio_start_show, NULL);
169 static struct portio_sysfs_entry portio_size_attribute =
170 __ATTR(size, S_IRUGO, portio_size_show, NULL);
171 static struct portio_sysfs_entry portio_porttype_attribute =
172 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
174 static struct attribute *portio_attrs[] = {
175 &portio_name_attribute.attr,
176 &portio_start_attribute.attr,
177 &portio_size_attribute.attr,
178 &portio_porttype_attribute.attr,
182 static void portio_release(struct kobject *kobj)
184 struct uio_portio *portio = to_portio(kobj);
188 static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
191 struct uio_portio *portio = to_portio(kobj);
192 struct uio_port *port = portio->port;
193 struct portio_sysfs_entry *entry;
195 entry = container_of(attr, struct portio_sysfs_entry, attr);
200 return entry->show(port, buf);
203 static const struct sysfs_ops portio_sysfs_ops = {
204 .show = portio_type_show,
207 static struct kobj_type portio_attr_type = {
208 .release = portio_release,
209 .sysfs_ops = &portio_sysfs_ops,
210 .default_attrs = portio_attrs,
213 static ssize_t name_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
216 struct uio_device *idev = dev_get_drvdata(dev);
219 mutex_lock(&idev->info_lock);
222 dev_err(dev, "the device has been unregistered\n");
226 ret = sprintf(buf, "%s\n", idev->info->name);
229 mutex_unlock(&idev->info_lock);
232 static DEVICE_ATTR_RO(name);
234 static ssize_t version_show(struct device *dev,
235 struct device_attribute *attr, char *buf)
237 struct uio_device *idev = dev_get_drvdata(dev);
240 mutex_lock(&idev->info_lock);
243 dev_err(dev, "the device has been unregistered\n");
247 ret = sprintf(buf, "%s\n", idev->info->version);
250 mutex_unlock(&idev->info_lock);
253 static DEVICE_ATTR_RO(version);
255 static ssize_t event_show(struct device *dev,
256 struct device_attribute *attr, char *buf)
258 struct uio_device *idev = dev_get_drvdata(dev);
259 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
261 static DEVICE_ATTR_RO(event);
263 static struct attribute *uio_attrs[] = {
265 &dev_attr_version.attr,
266 &dev_attr_event.attr,
269 ATTRIBUTE_GROUPS(uio);
271 /* UIO class infrastructure */
272 static struct class uio_class = {
274 .dev_groups = uio_groups,
280 static int uio_dev_add_attributes(struct uio_device *idev)
285 int portio_found = 0;
288 struct uio_port *port;
289 struct uio_portio *portio;
291 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
292 mem = &idev->info->mem[mi];
297 idev->map_dir = kobject_create_and_add("maps",
299 if (!idev->map_dir) {
304 map = kzalloc(sizeof(*map), GFP_KERNEL);
309 kobject_init(&map->kobj, &map_attr_type);
312 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
315 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
320 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
321 port = &idev->info->port[pi];
326 idev->portio_dir = kobject_create_and_add("portio",
328 if (!idev->portio_dir) {
333 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
338 kobject_init(&portio->kobj, &portio_attr_type);
340 port->portio = portio;
341 ret = kobject_add(&portio->kobj, idev->portio_dir,
344 goto err_portio_kobj;
345 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
347 goto err_portio_kobj;
355 for (; pi >= 0; pi--) {
356 port = &idev->info->port[pi];
357 portio = port->portio;
358 kobject_put(&portio->kobj);
360 kobject_put(idev->portio_dir);
364 for (; mi >= 0; mi--) {
365 mem = &idev->info->mem[mi];
367 kobject_put(&map->kobj);
369 kobject_put(idev->map_dir);
370 dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret);
374 static void uio_dev_del_attributes(struct uio_device *idev)
378 struct uio_port *port;
380 for (i = 0; i < MAX_UIO_MAPS; i++) {
381 mem = &idev->info->mem[i];
384 kobject_put(&mem->map->kobj);
386 kobject_put(idev->map_dir);
388 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
389 port = &idev->info->port[i];
392 kobject_put(&port->portio->kobj);
394 kobject_put(idev->portio_dir);
397 static int uio_get_minor(struct uio_device *idev)
399 int retval = -ENOMEM;
401 mutex_lock(&minor_lock);
402 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
404 idev->minor = retval;
406 } else if (retval == -ENOSPC) {
407 dev_err(&idev->dev, "too many uio devices\n");
410 mutex_unlock(&minor_lock);
414 static void uio_free_minor(struct uio_device *idev)
416 mutex_lock(&minor_lock);
417 idr_remove(&uio_idr, idev->minor);
418 mutex_unlock(&minor_lock);
422 * uio_event_notify - trigger an interrupt event
423 * @info: UIO device capabilities
425 void uio_event_notify(struct uio_info *info)
427 struct uio_device *idev = info->uio_dev;
429 atomic_inc(&idev->event);
430 wake_up_interruptible(&idev->wait);
431 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
433 EXPORT_SYMBOL_GPL(uio_event_notify);
436 * uio_interrupt - hardware interrupt handler
437 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
438 * @dev_id: Pointer to the devices uio_device structure
440 static irqreturn_t uio_interrupt(int irq, void *dev_id)
442 struct uio_device *idev = (struct uio_device *)dev_id;
445 mutex_lock(&idev->info_lock);
447 ret = idev->info->handler(irq, idev->info);
448 if (ret == IRQ_HANDLED)
449 uio_event_notify(idev->info);
451 mutex_unlock(&idev->info_lock);
455 struct uio_listener {
456 struct uio_device *dev;
460 static int uio_open(struct inode *inode, struct file *filep)
462 struct uio_device *idev;
463 struct uio_listener *listener;
466 mutex_lock(&minor_lock);
467 idev = idr_find(&uio_idr, iminor(inode));
468 mutex_unlock(&minor_lock);
474 get_device(&idev->dev);
476 if (!try_module_get(idev->owner)) {
481 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
484 goto err_alloc_listener;
487 listener->dev = idev;
488 listener->event_count = atomic_read(&idev->event);
489 filep->private_data = listener;
491 mutex_lock(&idev->info_lock);
493 mutex_unlock(&idev->info_lock);
495 goto err_alloc_listener;
498 if (idev->info && idev->info->open)
499 ret = idev->info->open(idev->info, inode);
500 mutex_unlock(&idev->info_lock);
510 module_put(idev->owner);
513 put_device(&idev->dev);
519 static int uio_fasync(int fd, struct file *filep, int on)
521 struct uio_listener *listener = filep->private_data;
522 struct uio_device *idev = listener->dev;
524 return fasync_helper(fd, filep, on, &idev->async_queue);
527 static int uio_release(struct inode *inode, struct file *filep)
530 struct uio_listener *listener = filep->private_data;
531 struct uio_device *idev = listener->dev;
533 mutex_lock(&idev->info_lock);
534 if (idev->info && idev->info->release)
535 ret = idev->info->release(idev->info, inode);
536 mutex_unlock(&idev->info_lock);
538 module_put(idev->owner);
540 put_device(&idev->dev);
544 static __poll_t uio_poll(struct file *filep, poll_table *wait)
546 struct uio_listener *listener = filep->private_data;
547 struct uio_device *idev = listener->dev;
550 mutex_lock(&idev->info_lock);
551 if (!idev->info || !idev->info->irq)
553 mutex_unlock(&idev->info_lock);
558 poll_wait(filep, &idev->wait, wait);
559 if (listener->event_count != atomic_read(&idev->event))
560 return EPOLLIN | EPOLLRDNORM;
564 static ssize_t uio_read(struct file *filep, char __user *buf,
565 size_t count, loff_t *ppos)
567 struct uio_listener *listener = filep->private_data;
568 struct uio_device *idev = listener->dev;
569 DECLARE_WAITQUEUE(wait, current);
573 mutex_lock(&idev->info_lock);
574 if (!idev->info || !idev->info->irq)
576 mutex_unlock(&idev->info_lock);
581 if (count != sizeof(s32))
584 add_wait_queue(&idev->wait, &wait);
587 set_current_state(TASK_INTERRUPTIBLE);
589 event_count = atomic_read(&idev->event);
590 if (event_count != listener->event_count) {
591 __set_current_state(TASK_RUNNING);
592 if (copy_to_user(buf, &event_count, count))
595 listener->event_count = event_count;
601 if (filep->f_flags & O_NONBLOCK) {
606 if (signal_pending(current)) {
607 retval = -ERESTARTSYS;
613 __set_current_state(TASK_RUNNING);
614 remove_wait_queue(&idev->wait, &wait);
619 static ssize_t uio_write(struct file *filep, const char __user *buf,
620 size_t count, loff_t *ppos)
622 struct uio_listener *listener = filep->private_data;
623 struct uio_device *idev = listener->dev;
627 if (count != sizeof(s32))
630 if (copy_from_user(&irq_on, buf, count))
633 mutex_lock(&idev->info_lock);
639 if (!idev->info || !idev->info->irq) {
644 if (!idev->info->irqcontrol) {
649 retval = idev->info->irqcontrol(idev->info, irq_on);
652 mutex_unlock(&idev->info_lock);
653 return retval ? retval : sizeof(s32);
656 static int uio_find_mem_index(struct vm_area_struct *vma)
658 struct uio_device *idev = vma->vm_private_data;
660 if (vma->vm_pgoff < MAX_UIO_MAPS) {
661 if (idev->info->mem[vma->vm_pgoff].size == 0)
663 return (int)vma->vm_pgoff;
668 static vm_fault_t uio_vma_fault(struct vm_fault *vmf)
670 struct uio_device *idev = vmf->vma->vm_private_data;
672 unsigned long offset;
677 mutex_lock(&idev->info_lock);
679 ret = VM_FAULT_SIGBUS;
683 mi = uio_find_mem_index(vmf->vma);
685 ret = VM_FAULT_SIGBUS;
690 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
693 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
695 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
696 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
697 page = virt_to_page(addr);
699 page = vmalloc_to_page(addr);
704 mutex_unlock(&idev->info_lock);
709 static const struct vm_operations_struct uio_logical_vm_ops = {
710 .fault = uio_vma_fault,
713 static int uio_mmap_logical(struct vm_area_struct *vma)
715 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
716 vma->vm_ops = &uio_logical_vm_ops;
720 static const struct vm_operations_struct uio_physical_vm_ops = {
721 #ifdef CONFIG_HAVE_IOREMAP_PROT
722 .access = generic_access_phys,
726 static int uio_mmap_physical(struct vm_area_struct *vma)
728 struct uio_device *idev = vma->vm_private_data;
729 int mi = uio_find_mem_index(vma);
734 mem = idev->info->mem + mi;
736 if (mem->addr & ~PAGE_MASK)
738 if (vma->vm_end - vma->vm_start > mem->size)
741 vma->vm_ops = &uio_physical_vm_ops;
742 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
745 * We cannot use the vm_iomap_memory() helper here,
746 * because vma->vm_pgoff is the map index we looked
747 * up above in uio_find_mem_index(), rather than an
748 * actual page offset into the mmap.
750 * So we just do the physical mmap without a page
753 return remap_pfn_range(vma,
755 mem->addr >> PAGE_SHIFT,
756 vma->vm_end - vma->vm_start,
760 static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
762 struct uio_listener *listener = filep->private_data;
763 struct uio_device *idev = listener->dev;
765 unsigned long requested_pages, actual_pages;
768 if (vma->vm_end < vma->vm_start)
771 vma->vm_private_data = idev;
773 mutex_lock(&idev->info_lock);
779 mi = uio_find_mem_index(vma);
785 requested_pages = vma_pages(vma);
786 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
787 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
788 if (requested_pages > actual_pages) {
793 if (idev->info->mmap) {
794 ret = idev->info->mmap(idev->info, vma);
798 switch (idev->info->mem[mi].memtype) {
800 ret = uio_mmap_physical(vma);
802 case UIO_MEM_LOGICAL:
803 case UIO_MEM_VIRTUAL:
804 ret = uio_mmap_logical(vma);
811 mutex_unlock(&idev->info_lock);
815 static const struct file_operations uio_fops = {
816 .owner = THIS_MODULE,
818 .release = uio_release,
823 .fasync = uio_fasync,
824 .llseek = noop_llseek,
827 static int uio_major_init(void)
829 static const char name[] = "uio";
830 struct cdev *cdev = NULL;
834 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
843 cdev->owner = THIS_MODULE;
844 cdev->ops = &uio_fops;
845 kobject_set_name(&cdev->kobj, "%s", name);
847 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
851 uio_major = MAJOR(uio_dev);
855 kobject_put(&cdev->kobj);
857 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
862 static void uio_major_cleanup(void)
864 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
868 static int init_uio_class(void)
872 /* This is the first time in here, set everything up properly */
873 ret = uio_major_init();
877 ret = class_register(&uio_class);
879 printk(KERN_ERR "class_register failed for uio\n");
880 goto err_class_register;
890 static void release_uio_class(void)
892 class_unregister(&uio_class);
896 static void uio_device_release(struct device *dev)
898 struct uio_device *idev = dev_get_drvdata(dev);
904 * uio_register_device - register a new userspace IO device
905 * @owner: module that creates the new device
906 * @parent: parent device
907 * @info: UIO device capabilities
909 * returns zero on success or a negative error code.
911 int __uio_register_device(struct module *owner,
912 struct device *parent,
913 struct uio_info *info)
915 struct uio_device *idev;
918 if (!parent || !info || !info->name || !info->version)
921 info->uio_dev = NULL;
923 idev = kzalloc(sizeof(*idev), GFP_KERNEL);
930 mutex_init(&idev->info_lock);
931 init_waitqueue_head(&idev->wait);
932 atomic_set(&idev->event, 0);
934 ret = uio_get_minor(idev);
938 idev->dev.devt = MKDEV(uio_major, idev->minor);
939 idev->dev.class = &uio_class;
940 idev->dev.parent = parent;
941 idev->dev.release = uio_device_release;
942 dev_set_drvdata(&idev->dev, idev);
944 ret = dev_set_name(&idev->dev, "uio%d", idev->minor);
946 goto err_device_create;
948 ret = device_register(&idev->dev);
950 goto err_device_create;
952 ret = uio_dev_add_attributes(idev);
954 goto err_uio_dev_add_attributes;
956 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
958 * Note that we deliberately don't use devm_request_irq
959 * here. The parent module can unregister the UIO device
960 * and call pci_disable_msi, which requires that this
961 * irq has been freed. However, the device may have open
962 * FDs at the time of unregister and therefore may not be
963 * freed until they are released.
965 ret = request_threaded_irq(info->irq, NULL, uio_interrupt,
966 info->irq_flags, info->name, idev);
969 goto err_request_irq;
972 info->uio_dev = idev;
976 uio_dev_del_attributes(idev);
977 err_uio_dev_add_attributes:
978 device_unregister(&idev->dev);
980 uio_free_minor(idev);
983 EXPORT_SYMBOL_GPL(__uio_register_device);
986 * uio_unregister_device - unregister a industrial IO device
987 * @info: UIO device capabilities
990 void uio_unregister_device(struct uio_info *info)
992 struct uio_device *idev;
994 if (!info || !info->uio_dev)
997 idev = info->uio_dev;
999 uio_free_minor(idev);
1001 mutex_lock(&idev->info_lock);
1002 uio_dev_del_attributes(idev);
1004 if (info->irq && info->irq != UIO_IRQ_CUSTOM)
1005 free_irq(info->irq, idev);
1008 mutex_unlock(&idev->info_lock);
1010 device_unregister(&idev->dev);
1014 EXPORT_SYMBOL_GPL(uio_unregister_device);
1016 static int __init uio_init(void)
1018 return init_uio_class();
1021 static void __exit uio_exit(void)
1023 release_uio_class();
1024 idr_destroy(&uio_idr);
1027 module_init(uio_init)
1028 module_exit(uio_exit)
1029 MODULE_LICENSE("GPL v2");