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Diffstat (limited to '')
| -rw-r--r-- | drivers/comedi/comedi_fops.c | 3437 |
1 files changed, 3437 insertions, 0 deletions
diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c new file mode 100644 index 000000000..e2114bcf8 --- /dev/null +++ b/drivers/comedi/comedi_fops.c @@ -0,0 +1,3437 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * comedi/comedi_fops.c + * comedi kernel module + * + * COMEDI - Linux Control and Measurement Device Interface + * Copyright (C) 1997-2007 David A. Schleef <ds@schleef.org> + * compat ioctls: + * Author: Ian Abbott, MEV Ltd. <abbotti@mev.co.uk> + * Copyright (C) 2007 MEV Ltd. <http://www.mev.co.uk/> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/sched/signal.h> +#include <linux/fcntl.h> +#include <linux/delay.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/poll.h> +#include <linux/device.h> +#include <linux/fs.h> +#include <linux/comedi/comedidev.h> +#include <linux/cdev.h> + +#include <linux/io.h> +#include <linux/uaccess.h> +#include <linux/compat.h> + +#include "comedi_internal.h" + +/* + * comedi_subdevice "runflags" + * COMEDI_SRF_RT: DEPRECATED: command is running real-time + * COMEDI_SRF_ERROR: indicates an COMEDI_CB_ERROR event has occurred + * since the last command was started + * COMEDI_SRF_RUNNING: command is running + * COMEDI_SRF_FREE_SPRIV: free s->private on detach + * + * COMEDI_SRF_BUSY_MASK: runflags that indicate the subdevice is "busy" + */ +#define COMEDI_SRF_RT BIT(1) +#define COMEDI_SRF_ERROR BIT(2) +#define COMEDI_SRF_RUNNING BIT(27) +#define COMEDI_SRF_FREE_SPRIV BIT(31) + +#define COMEDI_SRF_BUSY_MASK (COMEDI_SRF_ERROR | COMEDI_SRF_RUNNING) + +/** + * struct comedi_file - Per-file private data for COMEDI device + * @dev: COMEDI device. + * @read_subdev: Current "read" subdevice. + * @write_subdev: Current "write" subdevice. + * @last_detach_count: Last known detach count. + * @last_attached: Last known attached/detached state. + */ +struct comedi_file { + struct comedi_device *dev; + struct comedi_subdevice *read_subdev; + struct comedi_subdevice *write_subdev; + unsigned int last_detach_count; + unsigned int last_attached:1; +}; + +#define COMEDI_NUM_MINORS 0x100 +#define COMEDI_NUM_SUBDEVICE_MINORS \ + (COMEDI_NUM_MINORS - COMEDI_NUM_BOARD_MINORS) + +static unsigned short comedi_num_legacy_minors; +module_param(comedi_num_legacy_minors, ushort, 0444); +MODULE_PARM_DESC(comedi_num_legacy_minors, + "number of comedi minor devices to reserve for non-auto-configured devices (default 0)" + ); + +unsigned int comedi_default_buf_size_kb = CONFIG_COMEDI_DEFAULT_BUF_SIZE_KB; +module_param(comedi_default_buf_size_kb, uint, 0644); +MODULE_PARM_DESC(comedi_default_buf_size_kb, + "default asynchronous buffer size in KiB (default " + __MODULE_STRING(CONFIG_COMEDI_DEFAULT_BUF_SIZE_KB) ")"); + +unsigned int comedi_default_buf_maxsize_kb = + CONFIG_COMEDI_DEFAULT_BUF_MAXSIZE_KB; +module_param(comedi_default_buf_maxsize_kb, uint, 0644); +MODULE_PARM_DESC(comedi_default_buf_maxsize_kb, + "default maximum size of asynchronous buffer in KiB (default " + __MODULE_STRING(CONFIG_COMEDI_DEFAULT_BUF_MAXSIZE_KB) ")"); + +static DEFINE_MUTEX(comedi_board_minor_table_lock); +static struct comedi_device +*comedi_board_minor_table[COMEDI_NUM_BOARD_MINORS]; + +static DEFINE_MUTEX(comedi_subdevice_minor_table_lock); +/* Note: indexed by minor - COMEDI_NUM_BOARD_MINORS. */ +static struct comedi_subdevice +*comedi_subdevice_minor_table[COMEDI_NUM_SUBDEVICE_MINORS]; + +static struct class *comedi_class; +static struct cdev comedi_cdev; + +static void comedi_device_init(struct comedi_device *dev) +{ + kref_init(&dev->refcount); + spin_lock_init(&dev->spinlock); + mutex_init(&dev->mutex); + init_rwsem(&dev->attach_lock); + dev->minor = -1; +} + +static void comedi_dev_kref_release(struct kref *kref) +{ + struct comedi_device *dev = + container_of(kref, struct comedi_device, refcount); + + mutex_destroy(&dev->mutex); + put_device(dev->class_dev); + kfree(dev); +} + +/** + * comedi_dev_put() - Release a use of a COMEDI device + * @dev: COMEDI device. + * + * Must be called when a user of a COMEDI device is finished with it. + * When the last user of the COMEDI device calls this function, the + * COMEDI device is destroyed. + * + * Return: 1 if the COMEDI device is destroyed by this call or @dev is + * NULL, otherwise return 0. Callers must not assume the COMEDI + * device is still valid if this function returns 0. + */ +int comedi_dev_put(struct comedi_device *dev) +{ + if (dev) + return kref_put(&dev->refcount, comedi_dev_kref_release); + return 1; +} +EXPORT_SYMBOL_GPL(comedi_dev_put); + +static struct comedi_device *comedi_dev_get(struct comedi_device *dev) +{ + if (dev) + kref_get(&dev->refcount); + return dev; +} + +static void comedi_device_cleanup(struct comedi_device *dev) +{ + struct module *driver_module = NULL; + + if (!dev) + return; + mutex_lock(&dev->mutex); + if (dev->attached) + driver_module = dev->driver->module; + comedi_device_detach(dev); + if (driver_module && dev->use_count) + module_put(driver_module); + mutex_unlock(&dev->mutex); +} + +static bool comedi_clear_board_dev(struct comedi_device *dev) +{ + unsigned int i = dev->minor; + bool cleared = false; + + lockdep_assert_held(&dev->mutex); + mutex_lock(&comedi_board_minor_table_lock); + if (dev == comedi_board_minor_table[i]) { + comedi_board_minor_table[i] = NULL; + cleared = true; + } + mutex_unlock(&comedi_board_minor_table_lock); + return cleared; +} + +static struct comedi_device *comedi_clear_board_minor(unsigned int minor) +{ + struct comedi_device *dev; + + mutex_lock(&comedi_board_minor_table_lock); + dev = comedi_board_minor_table[minor]; + comedi_board_minor_table[minor] = NULL; + mutex_unlock(&comedi_board_minor_table_lock); + return dev; +} + +static void comedi_free_board_dev(struct comedi_device *dev) +{ + if (dev) { + comedi_device_cleanup(dev); + if (dev->class_dev) { + device_destroy(comedi_class, + MKDEV(COMEDI_MAJOR, dev->minor)); + } + comedi_dev_put(dev); + } +} + +static struct comedi_subdevice * +comedi_subdevice_from_minor(const struct comedi_device *dev, unsigned int minor) +{ + struct comedi_subdevice *s; + unsigned int i = minor - COMEDI_NUM_BOARD_MINORS; + + mutex_lock(&comedi_subdevice_minor_table_lock); + s = comedi_subdevice_minor_table[i]; + if (s && s->device != dev) + s = NULL; + mutex_unlock(&comedi_subdevice_minor_table_lock); + return s; +} + +static struct comedi_device *comedi_dev_get_from_board_minor(unsigned int minor) +{ + struct comedi_device *dev; + + mutex_lock(&comedi_board_minor_table_lock); + dev = comedi_dev_get(comedi_board_minor_table[minor]); + mutex_unlock(&comedi_board_minor_table_lock); + return dev; +} + +static struct comedi_device * +comedi_dev_get_from_subdevice_minor(unsigned int minor) +{ + struct comedi_device *dev; + struct comedi_subdevice *s; + unsigned int i = minor - COMEDI_NUM_BOARD_MINORS; + + mutex_lock(&comedi_subdevice_minor_table_lock); + s = comedi_subdevice_minor_table[i]; + dev = comedi_dev_get(s ? s->device : NULL); + mutex_unlock(&comedi_subdevice_minor_table_lock); + return dev; +} + +/** + * comedi_dev_get_from_minor() - Get COMEDI device by minor device number + * @minor: Minor device number. + * + * Finds the COMEDI device associated with the minor device number, if any, + * and increments its reference count. The COMEDI device is prevented from + * being freed until a matching call is made to comedi_dev_put(). + * + * Return: A pointer to the COMEDI device if it exists, with its usage + * reference incremented. Return NULL if no COMEDI device exists with the + * specified minor device number. + */ +struct comedi_device *comedi_dev_get_from_minor(unsigned int minor) +{ + if (minor < COMEDI_NUM_BOARD_MINORS) + return comedi_dev_get_from_board_minor(minor); + + return comedi_dev_get_from_subdevice_minor(minor); +} +EXPORT_SYMBOL_GPL(comedi_dev_get_from_minor); + +static struct comedi_subdevice * +comedi_read_subdevice(const struct comedi_device *dev, unsigned int minor) +{ + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->mutex); + if (minor >= COMEDI_NUM_BOARD_MINORS) { + s = comedi_subdevice_from_minor(dev, minor); + if (!s || (s->subdev_flags & SDF_CMD_READ)) + return s; + } + return dev->read_subdev; +} + +static struct comedi_subdevice * +comedi_write_subdevice(const struct comedi_device *dev, unsigned int minor) +{ + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->mutex); + if (minor >= COMEDI_NUM_BOARD_MINORS) { + s = comedi_subdevice_from_minor(dev, minor); + if (!s || (s->subdev_flags & SDF_CMD_WRITE)) + return s; + } + return dev->write_subdev; +} + +static void comedi_file_reset(struct file *file) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi_subdevice *s, *read_s, *write_s; + unsigned int minor = iminor(file_inode(file)); + + read_s = dev->read_subdev; + write_s = dev->write_subdev; + if (minor >= COMEDI_NUM_BOARD_MINORS) { + s = comedi_subdevice_from_minor(dev, minor); + if (!s || s->subdev_flags & SDF_CMD_READ) + read_s = s; + if (!s || s->subdev_flags & SDF_CMD_WRITE) + write_s = s; + } + cfp->last_attached = dev->attached; + cfp->last_detach_count = dev->detach_count; + WRITE_ONCE(cfp->read_subdev, read_s); + WRITE_ONCE(cfp->write_subdev, write_s); +} + +static void comedi_file_check(struct file *file) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + + if (cfp->last_attached != dev->attached || + cfp->last_detach_count != dev->detach_count) + comedi_file_reset(file); +} + +static struct comedi_subdevice *comedi_file_read_subdevice(struct file *file) +{ + struct comedi_file *cfp = file->private_data; + + comedi_file_check(file); + return READ_ONCE(cfp->read_subdev); +} + +static struct comedi_subdevice *comedi_file_write_subdevice(struct file *file) +{ + struct comedi_file *cfp = file->private_data; + + comedi_file_check(file); + return READ_ONCE(cfp->write_subdev); +} + +static int resize_async_buffer(struct comedi_device *dev, + struct comedi_subdevice *s, + unsigned int new_size) +{ + struct comedi_async *async = s->async; + int retval; + + lockdep_assert_held(&dev->mutex); + + if (new_size > async->max_bufsize) + return -EPERM; + + if (s->busy) { + dev_dbg(dev->class_dev, + "subdevice is busy, cannot resize buffer\n"); + return -EBUSY; + } + if (comedi_buf_is_mmapped(s)) { + dev_dbg(dev->class_dev, + "subdevice is mmapped, cannot resize buffer\n"); + return -EBUSY; + } + + /* make sure buffer is an integral number of pages (we round up) */ + new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK; + + retval = comedi_buf_alloc(dev, s, new_size); + if (retval < 0) + return retval; + + if (s->buf_change) { + retval = s->buf_change(dev, s); + if (retval < 0) + return retval; + } + + dev_dbg(dev->class_dev, "subd %d buffer resized to %i bytes\n", + s->index, async->prealloc_bufsz); + return 0; +} + +/* sysfs attribute files */ + +static ssize_t max_read_buffer_kb_show(struct device *csdev, + struct device_attribute *attr, char *buf) +{ + unsigned int minor = MINOR(csdev->devt); + struct comedi_device *dev; + struct comedi_subdevice *s; + unsigned int size = 0; + + dev = comedi_dev_get_from_minor(minor); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->mutex); + s = comedi_read_subdevice(dev, minor); + if (s && (s->subdev_flags & SDF_CMD_READ) && s->async) + size = s->async->max_bufsize / 1024; + mutex_unlock(&dev->mutex); + + comedi_dev_put(dev); + return sysfs_emit(buf, "%u\n", size); +} + +static ssize_t max_read_buffer_kb_store(struct device *csdev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + unsigned int minor = MINOR(csdev->devt); + struct comedi_device *dev; + struct comedi_subdevice *s; + unsigned int size; + int err; + + err = kstrtouint(buf, 10, &size); + if (err) + return err; + if (size > (UINT_MAX / 1024)) + return -EINVAL; + size *= 1024; + + dev = comedi_dev_get_from_minor(minor); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->mutex); + s = comedi_read_subdevice(dev, minor); + if (s && (s->subdev_flags & SDF_CMD_READ) && s->async) + s->async->max_bufsize = size; + else + err = -EINVAL; + mutex_unlock(&dev->mutex); + + comedi_dev_put(dev); + return err ? err : count; +} +static DEVICE_ATTR_RW(max_read_buffer_kb); + +static ssize_t read_buffer_kb_show(struct device *csdev, + struct device_attribute *attr, char *buf) +{ + unsigned int minor = MINOR(csdev->devt); + struct comedi_device *dev; + struct comedi_subdevice *s; + unsigned int size = 0; + + dev = comedi_dev_get_from_minor(minor); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->mutex); + s = comedi_read_subdevice(dev, minor); + if (s && (s->subdev_flags & SDF_CMD_READ) && s->async) + size = s->async->prealloc_bufsz / 1024; + mutex_unlock(&dev->mutex); + + comedi_dev_put(dev); + return sysfs_emit(buf, "%u\n", size); +} + +static ssize_t read_buffer_kb_store(struct device *csdev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + unsigned int minor = MINOR(csdev->devt); + struct comedi_device *dev; + struct comedi_subdevice *s; + unsigned int size; + int err; + + err = kstrtouint(buf, 10, &size); + if (err) + return err; + if (size > (UINT_MAX / 1024)) + return -EINVAL; + size *= 1024; + + dev = comedi_dev_get_from_minor(minor); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->mutex); + s = comedi_read_subdevice(dev, minor); + if (s && (s->subdev_flags & SDF_CMD_READ) && s->async) + err = resize_async_buffer(dev, s, size); + else + err = -EINVAL; + mutex_unlock(&dev->mutex); + + comedi_dev_put(dev); + return err ? err : count; +} +static DEVICE_ATTR_RW(read_buffer_kb); + +static ssize_t max_write_buffer_kb_show(struct device *csdev, + struct device_attribute *attr, + char *buf) +{ + unsigned int minor = MINOR(csdev->devt); + struct comedi_device *dev; + struct comedi_subdevice *s; + unsigned int size = 0; + + dev = comedi_dev_get_from_minor(minor); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->mutex); + s = comedi_write_subdevice(dev, minor); + if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async) + size = s->async->max_bufsize / 1024; + mutex_unlock(&dev->mutex); + + comedi_dev_put(dev); + return sysfs_emit(buf, "%u\n", size); +} + +static ssize_t max_write_buffer_kb_store(struct device *csdev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + unsigned int minor = MINOR(csdev->devt); + struct comedi_device *dev; + struct comedi_subdevice *s; + unsigned int size; + int err; + + err = kstrtouint(buf, 10, &size); + if (err) + return err; + if (size > (UINT_MAX / 1024)) + return -EINVAL; + size *= 1024; + + dev = comedi_dev_get_from_minor(minor); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->mutex); + s = comedi_write_subdevice(dev, minor); + if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async) + s->async->max_bufsize = size; + else + err = -EINVAL; + mutex_unlock(&dev->mutex); + + comedi_dev_put(dev); + return err ? err : count; +} +static DEVICE_ATTR_RW(max_write_buffer_kb); + +static ssize_t write_buffer_kb_show(struct device *csdev, + struct device_attribute *attr, char *buf) +{ + unsigned int minor = MINOR(csdev->devt); + struct comedi_device *dev; + struct comedi_subdevice *s; + unsigned int size = 0; + + dev = comedi_dev_get_from_minor(minor); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->mutex); + s = comedi_write_subdevice(dev, minor); + if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async) + size = s->async->prealloc_bufsz / 1024; + mutex_unlock(&dev->mutex); + + comedi_dev_put(dev); + return sysfs_emit(buf, "%u\n", size); +} + +static ssize_t write_buffer_kb_store(struct device *csdev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + unsigned int minor = MINOR(csdev->devt); + struct comedi_device *dev; + struct comedi_subdevice *s; + unsigned int size; + int err; + + err = kstrtouint(buf, 10, &size); + if (err) + return err; + if (size > (UINT_MAX / 1024)) + return -EINVAL; + size *= 1024; + + dev = comedi_dev_get_from_minor(minor); + if (!dev) + return -ENODEV; + + mutex_lock(&dev->mutex); + s = comedi_write_subdevice(dev, minor); + if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async) + err = resize_async_buffer(dev, s, size); + else + err = -EINVAL; + mutex_unlock(&dev->mutex); + + comedi_dev_put(dev); + return err ? err : count; +} +static DEVICE_ATTR_RW(write_buffer_kb); + +static struct attribute *comedi_dev_attrs[] = { + &dev_attr_max_read_buffer_kb.attr, + &dev_attr_read_buffer_kb.attr, + &dev_attr_max_write_buffer_kb.attr, + &dev_attr_write_buffer_kb.attr, + NULL, +}; +ATTRIBUTE_GROUPS(comedi_dev); + +static void __comedi_clear_subdevice_runflags(struct comedi_subdevice *s, + unsigned int bits) +{ + s->runflags &= ~bits; +} + +static void __comedi_set_subdevice_runflags(struct comedi_subdevice *s, + unsigned int bits) +{ + s->runflags |= bits; +} + +static void comedi_update_subdevice_runflags(struct comedi_subdevice *s, + unsigned int mask, + unsigned int bits) +{ + unsigned long flags; + + spin_lock_irqsave(&s->spin_lock, flags); + __comedi_clear_subdevice_runflags(s, mask); + __comedi_set_subdevice_runflags(s, bits & mask); + spin_unlock_irqrestore(&s->spin_lock, flags); +} + +static unsigned int __comedi_get_subdevice_runflags(struct comedi_subdevice *s) +{ + return s->runflags; +} + +static unsigned int comedi_get_subdevice_runflags(struct comedi_subdevice *s) +{ + unsigned long flags; + unsigned int runflags; + + spin_lock_irqsave(&s->spin_lock, flags); + runflags = __comedi_get_subdevice_runflags(s); + spin_unlock_irqrestore(&s->spin_lock, flags); + return runflags; +} + +static bool comedi_is_runflags_running(unsigned int runflags) +{ + return runflags & COMEDI_SRF_RUNNING; +} + +static bool comedi_is_runflags_in_error(unsigned int runflags) +{ + return runflags & COMEDI_SRF_ERROR; +} + +/** + * comedi_is_subdevice_running() - Check if async command running on subdevice + * @s: COMEDI subdevice. + * + * Return: %true if an asynchronous COMEDI command is active on the + * subdevice, else %false. + */ +bool comedi_is_subdevice_running(struct comedi_subdevice *s) +{ + unsigned int runflags = comedi_get_subdevice_runflags(s); + + return comedi_is_runflags_running(runflags); +} +EXPORT_SYMBOL_GPL(comedi_is_subdevice_running); + +static bool __comedi_is_subdevice_running(struct comedi_subdevice *s) +{ + unsigned int runflags = __comedi_get_subdevice_runflags(s); + + return comedi_is_runflags_running(runflags); +} + +bool comedi_can_auto_free_spriv(struct comedi_subdevice *s) +{ + unsigned int runflags = __comedi_get_subdevice_runflags(s); + + return runflags & COMEDI_SRF_FREE_SPRIV; +} + +/** + * comedi_set_spriv_auto_free() - Mark subdevice private data as freeable + * @s: COMEDI subdevice. + * + * Mark the subdevice as having a pointer to private data that can be + * automatically freed when the COMEDI device is detached from the low-level + * driver. + */ +void comedi_set_spriv_auto_free(struct comedi_subdevice *s) +{ + __comedi_set_subdevice_runflags(s, COMEDI_SRF_FREE_SPRIV); +} +EXPORT_SYMBOL_GPL(comedi_set_spriv_auto_free); + +/** + * comedi_alloc_spriv - Allocate memory for the subdevice private data + * @s: COMEDI subdevice. + * @size: Size of the memory to allocate. + * + * Allocate memory for the subdevice private data and point @s->private + * to it. The memory will be freed automatically when the COMEDI device + * is detached from the low-level driver. + * + * Return: A pointer to the allocated memory @s->private on success. + * Return NULL on failure. + */ +void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size) +{ + s->private = kzalloc(size, GFP_KERNEL); + if (s->private) + comedi_set_spriv_auto_free(s); + return s->private; +} +EXPORT_SYMBOL_GPL(comedi_alloc_spriv); + +/* + * This function restores a subdevice to an idle state. + */ +static void do_become_nonbusy(struct comedi_device *dev, + struct comedi_subdevice *s) +{ + struct comedi_async *async = s->async; + + lockdep_assert_held(&dev->mutex); + comedi_update_subdevice_runflags(s, COMEDI_SRF_RUNNING, 0); + if (async) { + comedi_buf_reset(s); + async->inttrig = NULL; + kfree(async->cmd.chanlist); + async->cmd.chanlist = NULL; + s->busy = NULL; + wake_up_interruptible_all(&async->wait_head); + } else { + dev_err(dev->class_dev, + "BUG: (?) %s called with async=NULL\n", __func__); + s->busy = NULL; + } +} + +static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s) +{ + int ret = 0; + + lockdep_assert_held(&dev->mutex); + if (comedi_is_subdevice_running(s) && s->cancel) + ret = s->cancel(dev, s); + + do_become_nonbusy(dev, s); + + return ret; +} + +void comedi_device_cancel_all(struct comedi_device *dev) +{ + struct comedi_subdevice *s; + int i; + + lockdep_assert_held(&dev->mutex); + if (!dev->attached) + return; + + for (i = 0; i < dev->n_subdevices; i++) { + s = &dev->subdevices[i]; + if (s->async) + do_cancel(dev, s); + } +} + +static int is_device_busy(struct comedi_device *dev) +{ + struct comedi_subdevice *s; + int i; + + lockdep_assert_held(&dev->mutex); + if (!dev->attached) + return 0; + + for (i = 0; i < dev->n_subdevices; i++) { + s = &dev->subdevices[i]; + if (s->busy) + return 1; + if (s->async && comedi_buf_is_mmapped(s)) + return 1; + } + + return 0; +} + +/* + * COMEDI_DEVCONFIG ioctl + * attaches (and configures) or detaches a legacy device + * + * arg: + * pointer to comedi_devconfig structure (NULL if detaching) + * + * reads: + * comedi_devconfig structure (if attaching) + * + * writes: + * nothing + */ +static int do_devconfig_ioctl(struct comedi_device *dev, + struct comedi_devconfig __user *arg) +{ + struct comedi_devconfig it; + + lockdep_assert_held(&dev->mutex); + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (!arg) { + if (is_device_busy(dev)) + return -EBUSY; + if (dev->attached) { + struct module *driver_module = dev->driver->module; + + comedi_device_detach(dev); + module_put(driver_module); + } + return 0; + } + + if (copy_from_user(&it, arg, sizeof(it))) + return -EFAULT; + + it.board_name[COMEDI_NAMELEN - 1] = 0; + + if (it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH]) { + dev_warn(dev->class_dev, + "comedi_config --init_data is deprecated\n"); + return -EINVAL; + } + + if (dev->minor >= comedi_num_legacy_minors) + /* don't re-use dynamically allocated comedi devices */ + return -EBUSY; + + /* This increments the driver module count on success. */ + return comedi_device_attach(dev, &it); +} + +/* + * COMEDI_BUFCONFIG ioctl + * buffer configuration + * + * arg: + * pointer to comedi_bufconfig structure + * + * reads: + * comedi_bufconfig structure + * + * writes: + * modified comedi_bufconfig structure + */ +static int do_bufconfig_ioctl(struct comedi_device *dev, + struct comedi_bufconfig __user *arg) +{ + struct comedi_bufconfig bc; + struct comedi_async *async; + struct comedi_subdevice *s; + int retval = 0; + + lockdep_assert_held(&dev->mutex); + if (copy_from_user(&bc, arg, sizeof(bc))) + return -EFAULT; + + if (bc.subdevice >= dev->n_subdevices) + return -EINVAL; + + s = &dev->subdevices[bc.subdevice]; + async = s->async; + + if (!async) { + dev_dbg(dev->class_dev, + "subdevice does not have async capability\n"); + bc.size = 0; + bc.maximum_size = 0; + goto copyback; + } + + if (bc.maximum_size) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + async->max_bufsize = bc.maximum_size; + } + + if (bc.size) { + retval = resize_async_buffer(dev, s, bc.size); + if (retval < 0) + return retval; + } + + bc.size = async->prealloc_bufsz; + bc.maximum_size = async->max_bufsize; + +copyback: + if (copy_to_user(arg, &bc, sizeof(bc))) + return -EFAULT; + + return 0; +} + +/* + * COMEDI_DEVINFO ioctl + * device info + * + * arg: + * pointer to comedi_devinfo structure + * + * reads: + * nothing + * + * writes: + * comedi_devinfo structure + */ +static int do_devinfo_ioctl(struct comedi_device *dev, + struct comedi_devinfo __user *arg, + struct file *file) +{ + struct comedi_subdevice *s; + struct comedi_devinfo devinfo; + + lockdep_assert_held(&dev->mutex); + memset(&devinfo, 0, sizeof(devinfo)); + + /* fill devinfo structure */ + devinfo.version_code = COMEDI_VERSION_CODE; + devinfo.n_subdevs = dev->n_subdevices; + strscpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN); + strscpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN); + + s = comedi_file_read_subdevice(file); + if (s) + devinfo.read_subdevice = s->index; + else + devinfo.read_subdevice = -1; + + s = comedi_file_write_subdevice(file); + if (s) + devinfo.write_subdevice = s->index; + else + devinfo.write_subdevice = -1; + + if (copy_to_user(arg, &devinfo, sizeof(devinfo))) + return -EFAULT; + + return 0; +} + +/* + * COMEDI_SUBDINFO ioctl + * subdevices info + * + * arg: + * pointer to array of comedi_subdinfo structures + * + * reads: + * nothing + * + * writes: + * array of comedi_subdinfo structures + */ +static int do_subdinfo_ioctl(struct comedi_device *dev, + struct comedi_subdinfo __user *arg, void *file) +{ + int ret, i; + struct comedi_subdinfo *tmp, *us; + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->mutex); + tmp = kcalloc(dev->n_subdevices, sizeof(*tmp), GFP_KERNEL); + if (!tmp) + return -ENOMEM; + + /* fill subdinfo structs */ + for (i = 0; i < dev->n_subdevices; i++) { + s = &dev->subdevices[i]; + us = tmp + i; + + us->type = s->type; + us->n_chan = s->n_chan; + us->subd_flags = s->subdev_flags; + if (comedi_is_subdevice_running(s)) + us->subd_flags |= SDF_RUNNING; +#define TIMER_nanosec 5 /* backwards compatibility */ + us->timer_type = TIMER_nanosec; + us->len_chanlist = s->len_chanlist; + us->maxdata = s->maxdata; + if (s->range_table) { + us->range_type = + (i << 24) | (0 << 16) | (s->range_table->length); + } else { + us->range_type = 0; /* XXX */ + } + + if (s->busy) + us->subd_flags |= SDF_BUSY; + if (s->busy == file) + us->subd_flags |= SDF_BUSY_OWNER; + if (s->lock) + us->subd_flags |= SDF_LOCKED; + if (s->lock == file) + us->subd_flags |= SDF_LOCK_OWNER; + if (!s->maxdata && s->maxdata_list) + us->subd_flags |= SDF_MAXDATA; + if (s->range_table_list) + us->subd_flags |= SDF_RANGETYPE; + if (s->do_cmd) + us->subd_flags |= SDF_CMD; + + if (s->insn_bits != &insn_inval) + us->insn_bits_support = COMEDI_SUPPORTED; + else + us->insn_bits_support = COMEDI_UNSUPPORTED; + } + + ret = copy_to_user(arg, tmp, dev->n_subdevices * sizeof(*tmp)); + + kfree(tmp); + + return ret ? -EFAULT : 0; +} + +/* + * COMEDI_CHANINFO ioctl + * subdevice channel info + * + * arg: + * pointer to comedi_chaninfo structure + * + * reads: + * comedi_chaninfo structure + * + * writes: + * array of maxdata values to chaninfo->maxdata_list if requested + * array of range table lengths to chaninfo->range_table_list if requested + */ +static int do_chaninfo_ioctl(struct comedi_device *dev, + struct comedi_chaninfo *it) +{ + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->mutex); + + if (it->subdev >= dev->n_subdevices) + return -EINVAL; + s = &dev->subdevices[it->subdev]; + + if (it->maxdata_list) { + if (s->maxdata || !s->maxdata_list) + return -EINVAL; + if (copy_to_user(it->maxdata_list, s->maxdata_list, + s->n_chan * sizeof(unsigned int))) + return -EFAULT; + } + + if (it->flaglist) + return -EINVAL; /* flaglist not supported */ + + if (it->rangelist) { + int i; + + if (!s->range_table_list) + return -EINVAL; + for (i = 0; i < s->n_chan; i++) { + int x; + + x = (dev->minor << 28) | (it->subdev << 24) | (i << 16) | + (s->range_table_list[i]->length); + if (put_user(x, it->rangelist + i)) + return -EFAULT; + } + } + + return 0; +} + +/* + * COMEDI_BUFINFO ioctl + * buffer information + * + * arg: + * pointer to comedi_bufinfo structure + * + * reads: + * comedi_bufinfo structure + * + * writes: + * modified comedi_bufinfo structure + */ +static int do_bufinfo_ioctl(struct comedi_device *dev, + struct comedi_bufinfo __user *arg, void *file) +{ + struct comedi_bufinfo bi; + struct comedi_subdevice *s; + struct comedi_async *async; + unsigned int runflags; + int retval = 0; + bool become_nonbusy = false; + + lockdep_assert_held(&dev->mutex); + if (copy_from_user(&bi, arg, sizeof(bi))) + return -EFAULT; + + if (bi.subdevice >= dev->n_subdevices) + return -EINVAL; + + s = &dev->subdevices[bi.subdevice]; + + async = s->async; + + if (!async || s->busy != file) + return -EINVAL; + + runflags = comedi_get_subdevice_runflags(s); + if (!(async->cmd.flags & CMDF_WRITE)) { + /* command was set up in "read" direction */ + if (bi.bytes_read) { + comedi_buf_read_alloc(s, bi.bytes_read); + bi.bytes_read = comedi_buf_read_free(s, bi.bytes_read); + } + /* + * If nothing left to read, and command has stopped, and + * {"read" position not updated or command stopped normally}, + * then become non-busy. + */ + if (comedi_buf_read_n_available(s) == 0 && + !comedi_is_runflags_running(runflags) && + (bi.bytes_read == 0 || + !comedi_is_runflags_in_error(runflags))) { + become_nonbusy = true; + if (comedi_is_runflags_in_error(runflags)) + retval = -EPIPE; + } + bi.bytes_written = 0; + } else { + /* command was set up in "write" direction */ + if (!comedi_is_runflags_running(runflags)) { + bi.bytes_written = 0; + become_nonbusy = true; + if (comedi_is_runflags_in_error(runflags)) + retval = -EPIPE; + } else if (bi.bytes_written) { + comedi_buf_write_alloc(s, bi.bytes_written); + bi.bytes_written = + comedi_buf_write_free(s, bi.bytes_written); + } + bi.bytes_read = 0; + } + + bi.buf_write_count = async->buf_write_count; + bi.buf_write_ptr = async->buf_write_ptr; + bi.buf_read_count = async->buf_read_count; + bi.buf_read_ptr = async->buf_read_ptr; + + if (become_nonbusy) + do_become_nonbusy(dev, s); + + if (retval) + return retval; + + if (copy_to_user(arg, &bi, sizeof(bi))) + return -EFAULT; + + return 0; +} + +static int check_insn_config_length(struct comedi_insn *insn, + unsigned int *data) +{ + if (insn->n < 1) + return -EINVAL; + + switch (data[0]) { + case INSN_CONFIG_DIO_OUTPUT: + case INSN_CONFIG_DIO_INPUT: + case INSN_CONFIG_DISARM: + case INSN_CONFIG_RESET: + if (insn->n == 1) + return 0; + break; + case INSN_CONFIG_ARM: + case INSN_CONFIG_DIO_QUERY: + case INSN_CONFIG_BLOCK_SIZE: + case INSN_CONFIG_FILTER: + case INSN_CONFIG_SERIAL_CLOCK: + case INSN_CONFIG_BIDIRECTIONAL_DATA: + case INSN_CONFIG_ALT_SOURCE: + case INSN_CONFIG_SET_COUNTER_MODE: + case INSN_CONFIG_8254_READ_STATUS: + case INSN_CONFIG_SET_ROUTING: + case INSN_CONFIG_GET_ROUTING: + case INSN_CONFIG_GET_PWM_STATUS: + case INSN_CONFIG_PWM_SET_PERIOD: + case INSN_CONFIG_PWM_GET_PERIOD: + if (insn->n == 2) + return 0; + break; + case INSN_CONFIG_SET_GATE_SRC: + case INSN_CONFIG_GET_GATE_SRC: + case INSN_CONFIG_SET_CLOCK_SRC: + case INSN_CONFIG_GET_CLOCK_SRC: + case INSN_CONFIG_SET_OTHER_SRC: + case INSN_CONFIG_GET_COUNTER_STATUS: + case INSN_CONFIG_PWM_SET_H_BRIDGE: + case INSN_CONFIG_PWM_GET_H_BRIDGE: + case INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE: + if (insn->n == 3) + return 0; + break; + case INSN_CONFIG_PWM_OUTPUT: + case INSN_CONFIG_ANALOG_TRIG: + case INSN_CONFIG_TIMER_1: + if (insn->n == 5) + return 0; + break; + case INSN_CONFIG_DIGITAL_TRIG: + if (insn->n == 6) + return 0; + break; + case INSN_CONFIG_GET_CMD_TIMING_CONSTRAINTS: + if (insn->n >= 4) + return 0; + break; + /* + * by default we allow the insn since we don't have checks for + * all possible cases yet + */ + default: + pr_warn("No check for data length of config insn id %i is implemented\n", + data[0]); + pr_warn("Add a check to %s in %s\n", __func__, __FILE__); + pr_warn("Assuming n=%i is correct\n", insn->n); + return 0; + } + return -EINVAL; +} + +static int check_insn_device_config_length(struct comedi_insn *insn, + unsigned int *data) +{ + if (insn->n < 1) + return -EINVAL; + + switch (data[0]) { + case INSN_DEVICE_CONFIG_TEST_ROUTE: + case INSN_DEVICE_CONFIG_CONNECT_ROUTE: + case INSN_DEVICE_CONFIG_DISCONNECT_ROUTE: + if (insn->n == 3) + return 0; + break; + case INSN_DEVICE_CONFIG_GET_ROUTES: + /* + * Big enough for config_id and the length of the userland + * memory buffer. Additional length should be in factors of 2 + * to communicate any returned route pairs (source,destination). + */ + if (insn->n >= 2) + return 0; + break; + } + return -EINVAL; +} + +/** + * get_valid_routes() - Calls low-level driver get_valid_routes function to + * either return a count of valid routes to user, or copy + * of list of all valid device routes to buffer in + * userspace. + * @dev: comedi device pointer + * @data: data from user insn call. The length of the data must be >= 2. + * data[0] must contain the INSN_DEVICE_CONFIG config_id. + * data[1](input) contains the number of _pairs_ for which memory is + * allotted from the user. If the user specifies '0', then only + * the number of pairs available is returned. + * data[1](output) returns either the number of pairs available (if none + * where requested) or the number of _pairs_ that are copied back + * to the user. + * data[2::2] returns each (source, destination) pair. + * + * Return: -EINVAL if low-level driver does not allocate and return routes as + * expected. Returns 0 otherwise. + */ +static int get_valid_routes(struct comedi_device *dev, unsigned int *data) +{ + lockdep_assert_held(&dev->mutex); + data[1] = dev->get_valid_routes(dev, data[1], data + 2); + return 0; +} + +static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn, + unsigned int *data, void *file) +{ + struct comedi_subdevice *s; + int ret = 0; + int i; + + lockdep_assert_held(&dev->mutex); + if (insn->insn & INSN_MASK_SPECIAL) { + /* a non-subdevice instruction */ + + switch (insn->insn) { + case INSN_GTOD: + { + struct timespec64 tv; + + if (insn->n != 2) { + ret = -EINVAL; + break; + } + + ktime_get_real_ts64(&tv); + /* unsigned data safe until 2106 */ + data[0] = (unsigned int)tv.tv_sec; + data[1] = tv.tv_nsec / NSEC_PER_USEC; + ret = 2; + + break; + } + case INSN_WAIT: + if (insn->n != 1 || data[0] >= 100000) { + ret = -EINVAL; + break; + } + udelay(data[0] / 1000); + ret = 1; + break; + case INSN_INTTRIG: + if (insn->n != 1) { + ret = -EINVAL; + break; + } + if (insn->subdev >= dev->n_subdevices) { + dev_dbg(dev->class_dev, + "%d not usable subdevice\n", + insn->subdev); + ret = -EINVAL; + break; + } + s = &dev->subdevices[insn->subdev]; + if (!s->async) { + dev_dbg(dev->class_dev, "no async\n"); + ret = -EINVAL; + break; + } + if (!s->async->inttrig) { + dev_dbg(dev->class_dev, "no inttrig\n"); + ret = -EAGAIN; + break; + } + ret = s->async->inttrig(dev, s, data[0]); + if (ret >= 0) + ret = 1; + break; + case INSN_DEVICE_CONFIG: + ret = check_insn_device_config_length(insn, data); + if (ret) + break; + + if (data[0] == INSN_DEVICE_CONFIG_GET_ROUTES) { + /* + * data[1] should be the number of _pairs_ that + * the memory can hold. + */ + data[1] = (insn->n - 2) / 2; + ret = get_valid_routes(dev, data); + break; + } + + /* other global device config instructions. */ + ret = dev->insn_device_config(dev, insn, data); + break; + default: + dev_dbg(dev->class_dev, "invalid insn\n"); + ret = -EINVAL; + break; + } + } else { + /* a subdevice instruction */ + unsigned int maxdata; + + if (insn->subdev >= dev->n_subdevices) { + dev_dbg(dev->class_dev, "subdevice %d out of range\n", + insn->subdev); + ret = -EINVAL; + goto out; + } + s = &dev->subdevices[insn->subdev]; + + if (s->type == COMEDI_SUBD_UNUSED) { + dev_dbg(dev->class_dev, "%d not usable subdevice\n", + insn->subdev); + ret = -EIO; + goto out; + } + + /* are we locked? (ioctl lock) */ + if (s->lock && s->lock != file) { + dev_dbg(dev->class_dev, "device locked\n"); + ret = -EACCES; + goto out; + } + + ret = comedi_check_chanlist(s, 1, &insn->chanspec); + if (ret < 0) { + ret = -EINVAL; + dev_dbg(dev->class_dev, "bad chanspec\n"); + goto out; + } + + if (s->busy) { + ret = -EBUSY; + goto out; + } + /* This looks arbitrary. It is. */ + s->busy = parse_insn; + switch (insn->insn) { + case INSN_READ: + ret = s->insn_read(dev, s, insn, data); + if (ret == -ETIMEDOUT) { + dev_dbg(dev->class_dev, + "subdevice %d read instruction timed out\n", + s->index); + } + break; + case INSN_WRITE: + maxdata = s->maxdata_list + ? s->maxdata_list[CR_CHAN(insn->chanspec)] + : s->maxdata; + for (i = 0; i < insn->n; ++i) { + if (data[i] > maxdata) { + ret = -EINVAL; + dev_dbg(dev->class_dev, + "bad data value(s)\n"); + break; + } + } + if (ret == 0) { + ret = s->insn_write(dev, s, insn, data); + if (ret == -ETIMEDOUT) { + dev_dbg(dev->class_dev, + "subdevice %d write instruction timed out\n", + s->index); + } + } + break; + case INSN_BITS: + if (insn->n != 2) { + ret = -EINVAL; + } else { + /* + * Most drivers ignore the base channel in + * insn->chanspec. Fix this here if + * the subdevice has <= 32 channels. + */ + unsigned int orig_mask = data[0]; + unsigned int shift = 0; + + if (s->n_chan <= 32) { + shift = CR_CHAN(insn->chanspec); + if (shift > 0) { + insn->chanspec = 0; + data[0] <<= shift; + data[1] <<= shift; + } + } + ret = s->insn_bits(dev, s, insn, data); + data[0] = orig_mask; + if (shift > 0) + data[1] >>= shift; + } + break; + case INSN_CONFIG: + ret = check_insn_config_length(insn, data); + if (ret) + break; + ret = s->insn_config(dev, s, insn, data); + break; + default: + ret = -EINVAL; + break; + } + + s->busy = NULL; + } + +out: + return ret; +} + +/* + * COMEDI_INSNLIST ioctl + * synchronous instruction list + * + * arg: + * pointer to comedi_insnlist structure + * + * reads: + * comedi_insnlist structure + * array of comedi_insn structures from insnlist->insns pointer + * data (for writes) from insns[].data pointers + * + * writes: + * data (for reads) to insns[].data pointers + */ +/* arbitrary limits */ +#define MIN_SAMPLES 16 +#define MAX_SAMPLES 65536 +static int do_insnlist_ioctl(struct comedi_device *dev, + struct comedi_insn *insns, + unsigned int n_insns, + void *file) +{ + unsigned int *data = NULL; + unsigned int max_n_data_required = MIN_SAMPLES; + int i = 0; + int ret = 0; + + lockdep_assert_held(&dev->mutex); + + /* Determine maximum memory needed for all instructions. */ + for (i = 0; i < n_insns; ++i) { + if (insns[i].n > MAX_SAMPLES) { + dev_dbg(dev->class_dev, + "number of samples too large\n"); + ret = -EINVAL; + goto error; + } + max_n_data_required = max(max_n_data_required, insns[i].n); + } + + /* Allocate scratch space for all instruction data. */ + data = kmalloc_array(max_n_data_required, sizeof(unsigned int), + GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto error; + } + + for (i = 0; i < n_insns; ++i) { + if (insns[i].insn & INSN_MASK_WRITE) { + if (copy_from_user(data, insns[i].data, + insns[i].n * sizeof(unsigned int))) { + dev_dbg(dev->class_dev, + "copy_from_user failed\n"); + ret = -EFAULT; + goto error; + } + } + ret = parse_insn(dev, insns + i, data, file); + if (ret < 0) + goto error; + if (insns[i].insn & INSN_MASK_READ) { + if (copy_to_user(insns[i].data, data, + insns[i].n * sizeof(unsigned int))) { + dev_dbg(dev->class_dev, + "copy_to_user failed\n"); + ret = -EFAULT; + goto error; + } + } + if (need_resched()) + schedule(); + } + +error: + kfree(data); + + if (ret < 0) + return ret; + return i; +} + +/* + * COMEDI_INSN ioctl + * synchronous instruction + * + * arg: + * pointer to comedi_insn structure + * + * reads: + * comedi_insn structure + * data (for writes) from insn->data pointer + * + * writes: + * data (for reads) to insn->data pointer + */ +static int do_insn_ioctl(struct comedi_device *dev, + struct comedi_insn *insn, void *file) +{ + unsigned int *data = NULL; + unsigned int n_data = MIN_SAMPLES; + int ret = 0; + + lockdep_assert_held(&dev->mutex); + + n_data = max(n_data, insn->n); + + /* This is where the behavior of insn and insnlist deviate. */ + if (insn->n > MAX_SAMPLES) { + insn->n = MAX_SAMPLES; + n_data = MAX_SAMPLES; + } + + data = kmalloc_array(n_data, sizeof(unsigned int), GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto error; + } + + if (insn->insn & INSN_MASK_WRITE) { + if (copy_from_user(data, + insn->data, + insn->n * sizeof(unsigned int))) { + ret = -EFAULT; + goto error; + } + } + ret = parse_insn(dev, insn, data, file); + if (ret < 0) + goto error; + if (insn->insn & INSN_MASK_READ) { + if (copy_to_user(insn->data, + data, + insn->n * sizeof(unsigned int))) { + ret = -EFAULT; + goto error; + } + } + ret = insn->n; + +error: + kfree(data); + + return ret; +} + +static int __comedi_get_user_cmd(struct comedi_device *dev, + struct comedi_cmd *cmd) +{ + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->mutex); + if (cmd->subdev >= dev->n_subdevices) { + dev_dbg(dev->class_dev, "%d no such subdevice\n", cmd->subdev); + return -ENODEV; + } + + s = &dev->subdevices[cmd->subdev]; + + if (s->type == COMEDI_SUBD_UNUSED) { + dev_dbg(dev->class_dev, "%d not valid subdevice\n", + cmd->subdev); + return -EIO; + } + + if (!s->do_cmd || !s->do_cmdtest || !s->async) { + dev_dbg(dev->class_dev, + "subdevice %d does not support commands\n", + cmd->subdev); + return -EIO; + } + + /* make sure channel/gain list isn't too long */ + if (cmd->chanlist_len > s->len_chanlist) { + dev_dbg(dev->class_dev, "channel/gain list too long %d > %d\n", + cmd->chanlist_len, s->len_chanlist); + return -EINVAL; + } + + /* + * Set the CMDF_WRITE flag to the correct state if the subdevice + * supports only "read" commands or only "write" commands. + */ + switch (s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) { + case SDF_CMD_READ: + cmd->flags &= ~CMDF_WRITE; + break; + case SDF_CMD_WRITE: + cmd->flags |= CMDF_WRITE; + break; + default: + break; + } + + return 0; +} + +static int __comedi_get_user_chanlist(struct comedi_device *dev, + struct comedi_subdevice *s, + unsigned int __user *user_chanlist, + struct comedi_cmd *cmd) +{ + unsigned int *chanlist; + int ret; + + lockdep_assert_held(&dev->mutex); + cmd->chanlist = NULL; + chanlist = memdup_user(user_chanlist, + cmd->chanlist_len * sizeof(unsigned int)); + if (IS_ERR(chanlist)) + return PTR_ERR(chanlist); + + /* make sure each element in channel/gain list is valid */ + ret = comedi_check_chanlist(s, cmd->chanlist_len, chanlist); + if (ret < 0) { + kfree(chanlist); + return ret; + } + + cmd->chanlist = chanlist; + + return 0; +} + +/* + * COMEDI_CMD ioctl + * asynchronous acquisition command set-up + * + * arg: + * pointer to comedi_cmd structure + * + * reads: + * comedi_cmd structure + * channel/range list from cmd->chanlist pointer + * + * writes: + * possibly modified comedi_cmd structure (when -EAGAIN returned) + */ +static int do_cmd_ioctl(struct comedi_device *dev, + struct comedi_cmd *cmd, bool *copy, void *file) +{ + struct comedi_subdevice *s; + struct comedi_async *async; + unsigned int __user *user_chanlist; + int ret; + + lockdep_assert_held(&dev->mutex); + + /* do some simple cmd validation */ + ret = __comedi_get_user_cmd(dev, cmd); + if (ret) + return ret; + + /* save user's chanlist pointer so it can be restored later */ + user_chanlist = (unsigned int __user *)cmd->chanlist; + + s = &dev->subdevices[cmd->subdev]; + async = s->async; + + /* are we locked? (ioctl lock) */ + if (s->lock && s->lock != file) { + dev_dbg(dev->class_dev, "subdevice locked\n"); + return -EACCES; + } + + /* are we busy? */ + if (s->busy) { + dev_dbg(dev->class_dev, "subdevice busy\n"); + return -EBUSY; + } + + /* make sure channel/gain list isn't too short */ + if (cmd->chanlist_len < 1) { + dev_dbg(dev->class_dev, "channel/gain list too short %u < 1\n", + cmd->chanlist_len); + return -EINVAL; + } + + async->cmd = *cmd; + async->cmd.data = NULL; + + /* load channel/gain list */ + ret = __comedi_get_user_chanlist(dev, s, user_chanlist, &async->cmd); + if (ret) + goto cleanup; + + ret = s->do_cmdtest(dev, s, &async->cmd); + + if (async->cmd.flags & CMDF_BOGUS || ret) { + dev_dbg(dev->class_dev, "test returned %d\n", ret); + *cmd = async->cmd; + /* restore chanlist pointer before copying back */ + cmd->chanlist = (unsigned int __force *)user_chanlist; + cmd->data = NULL; + *copy = true; + ret = -EAGAIN; + goto cleanup; + } + + if (!async->prealloc_bufsz) { + ret = -ENOMEM; + dev_dbg(dev->class_dev, "no buffer (?)\n"); + goto cleanup; + } + + comedi_buf_reset(s); + + async->cb_mask = COMEDI_CB_BLOCK | COMEDI_CB_CANCEL_MASK; + if (async->cmd.flags & CMDF_WAKE_EOS) + async->cb_mask |= COMEDI_CB_EOS; + + comedi_update_subdevice_runflags(s, COMEDI_SRF_BUSY_MASK, + COMEDI_SRF_RUNNING); + + /* + * Set s->busy _after_ setting COMEDI_SRF_RUNNING flag to avoid + * race with comedi_read() or comedi_write(). + */ + s->busy = file; + ret = s->do_cmd(dev, s); + if (ret == 0) + return 0; + +cleanup: + do_become_nonbusy(dev, s); + + return ret; +} + +/* + * COMEDI_CMDTEST ioctl + * asynchronous acquisition command testing + * + * arg: + * pointer to comedi_cmd structure + * + * reads: + * comedi_cmd structure + * channel/range list from cmd->chanlist pointer + * + * writes: + * possibly modified comedi_cmd structure + */ +static int do_cmdtest_ioctl(struct comedi_device *dev, + struct comedi_cmd *cmd, bool *copy, void *file) +{ + struct comedi_subdevice *s; + unsigned int __user *user_chanlist; + int ret; + + lockdep_assert_held(&dev->mutex); + + /* do some simple cmd validation */ + ret = __comedi_get_user_cmd(dev, cmd); + if (ret) + return ret; + + /* save user's chanlist pointer so it can be restored later */ + user_chanlist = (unsigned int __user *)cmd->chanlist; + + s = &dev->subdevices[cmd->subdev]; + + /* user_chanlist can be NULL for COMEDI_CMDTEST ioctl */ + if (user_chanlist) { + /* load channel/gain list */ + ret = __comedi_get_user_chanlist(dev, s, user_chanlist, cmd); + if (ret) + return ret; + } + + ret = s->do_cmdtest(dev, s, cmd); + + kfree(cmd->chanlist); /* free kernel copy of user chanlist */ + + /* restore chanlist pointer before copying back */ + cmd->chanlist = (unsigned int __force *)user_chanlist; + *copy = true; + + return ret; +} + +/* + * COMEDI_LOCK ioctl + * lock subdevice + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ +static int do_lock_ioctl(struct comedi_device *dev, unsigned long arg, + void *file) +{ + int ret = 0; + unsigned long flags; + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->mutex); + if (arg >= dev->n_subdevices) + return -EINVAL; + s = &dev->subdevices[arg]; + + spin_lock_irqsave(&s->spin_lock, flags); + if (s->busy || s->lock) + ret = -EBUSY; + else + s->lock = file; + spin_unlock_irqrestore(&s->spin_lock, flags); + + return ret; +} + +/* + * COMEDI_UNLOCK ioctl + * unlock subdevice + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ +static int do_unlock_ioctl(struct comedi_device *dev, unsigned long arg, + void *file) +{ + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->mutex); + if (arg >= dev->n_subdevices) + return -EINVAL; + s = &dev->subdevices[arg]; + + if (s->busy) + return -EBUSY; + + if (s->lock && s->lock != file) + return -EACCES; + + if (s->lock == file) + s->lock = NULL; + + return 0; +} + +/* + * COMEDI_CANCEL ioctl + * cancel asynchronous acquisition + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ +static int do_cancel_ioctl(struct comedi_device *dev, unsigned long arg, + void *file) +{ + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->mutex); + if (arg >= dev->n_subdevices) + return -EINVAL; + s = &dev->subdevices[arg]; + if (!s->async) + return -EINVAL; + + if (!s->busy) + return 0; + + if (s->busy != file) + return -EBUSY; + + return do_cancel(dev, s); +} + +/* + * COMEDI_POLL ioctl + * instructs driver to synchronize buffers + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ +static int do_poll_ioctl(struct comedi_device *dev, unsigned long arg, + void *file) +{ + struct comedi_subdevice *s; + + lockdep_assert_held(&dev->mutex); + if (arg >= dev->n_subdevices) + return -EINVAL; + s = &dev->subdevices[arg]; + + if (!s->busy) + return 0; + + if (s->busy != file) + return -EBUSY; + + if (s->poll) + return s->poll(dev, s); + + return -EINVAL; +} + +/* + * COMEDI_SETRSUBD ioctl + * sets the current "read" subdevice on a per-file basis + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ +static int do_setrsubd_ioctl(struct comedi_device *dev, unsigned long arg, + struct file *file) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_subdevice *s_old, *s_new; + + lockdep_assert_held(&dev->mutex); + if (arg >= dev->n_subdevices) + return -EINVAL; + + s_new = &dev->subdevices[arg]; + s_old = comedi_file_read_subdevice(file); + if (s_old == s_new) + return 0; /* no change */ + + if (!(s_new->subdev_flags & SDF_CMD_READ)) + return -EINVAL; + + /* + * Check the file isn't still busy handling a "read" command on the + * old subdevice (if any). + */ + if (s_old && s_old->busy == file && s_old->async && + !(s_old->async->cmd.flags & CMDF_WRITE)) + return -EBUSY; + + WRITE_ONCE(cfp->read_subdev, s_new); + return 0; +} + +/* + * COMEDI_SETWSUBD ioctl + * sets the current "write" subdevice on a per-file basis + * + * arg: + * subdevice number + * + * reads: + * nothing + * + * writes: + * nothing + */ +static int do_setwsubd_ioctl(struct comedi_device *dev, unsigned long arg, + struct file *file) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_subdevice *s_old, *s_new; + + lockdep_assert_held(&dev->mutex); + if (arg >= dev->n_subdevices) + return -EINVAL; + + s_new = &dev->subdevices[arg]; + s_old = comedi_file_write_subdevice(file); + if (s_old == s_new) + return 0; /* no change */ + + if (!(s_new->subdev_flags & SDF_CMD_WRITE)) + return -EINVAL; + + /* + * Check the file isn't still busy handling a "write" command on the + * old subdevice (if any). + */ + if (s_old && s_old->busy == file && s_old->async && + (s_old->async->cmd.flags & CMDF_WRITE)) + return -EBUSY; + + WRITE_ONCE(cfp->write_subdev, s_new); + return 0; +} + +static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + unsigned int minor = iminor(file_inode(file)); + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + int rc; + + mutex_lock(&dev->mutex); + + /* + * Device config is special, because it must work on + * an unconfigured device. + */ + if (cmd == COMEDI_DEVCONFIG) { + if (minor >= COMEDI_NUM_BOARD_MINORS) { + /* Device config not appropriate on non-board minors. */ + rc = -ENOTTY; + goto done; + } + rc = do_devconfig_ioctl(dev, + (struct comedi_devconfig __user *)arg); + if (rc == 0) { + if (arg == 0 && + dev->minor >= comedi_num_legacy_minors) { + /* + * Successfully unconfigured a dynamically + * allocated device. Try and remove it. + */ + if (comedi_clear_board_dev(dev)) { + mutex_unlock(&dev->mutex); + comedi_free_board_dev(dev); + return rc; + } + } + } + goto done; + } + + if (!dev->attached) { + dev_dbg(dev->class_dev, "no driver attached\n"); + rc = -ENODEV; + goto done; + } + + switch (cmd) { + case COMEDI_BUFCONFIG: + rc = do_bufconfig_ioctl(dev, + (struct comedi_bufconfig __user *)arg); + break; + case COMEDI_DEVINFO: + rc = do_devinfo_ioctl(dev, (struct comedi_devinfo __user *)arg, + file); + break; + case COMEDI_SUBDINFO: + rc = do_subdinfo_ioctl(dev, + (struct comedi_subdinfo __user *)arg, + file); + break; + case COMEDI_CHANINFO: { + struct comedi_chaninfo it; + + if (copy_from_user(&it, (void __user *)arg, sizeof(it))) + rc = -EFAULT; + else + rc = do_chaninfo_ioctl(dev, &it); + break; + } + case COMEDI_RANGEINFO: { + struct comedi_rangeinfo it; + + if (copy_from_user(&it, (void __user *)arg, sizeof(it))) + rc = -EFAULT; + else + rc = do_rangeinfo_ioctl(dev, &it); + break; + } + case COMEDI_BUFINFO: + rc = do_bufinfo_ioctl(dev, + (struct comedi_bufinfo __user *)arg, + file); + break; + case COMEDI_LOCK: + rc = do_lock_ioctl(dev, arg, file); + break; + case COMEDI_UNLOCK: + rc = do_unlock_ioctl(dev, arg, file); + break; + case COMEDI_CANCEL: + rc = do_cancel_ioctl(dev, arg, file); + break; + case COMEDI_CMD: { + struct comedi_cmd cmd; + bool copy = false; + + if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) { + rc = -EFAULT; + break; + } + rc = do_cmd_ioctl(dev, &cmd, ©, file); + if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd))) + rc = -EFAULT; + break; + } + case COMEDI_CMDTEST: { + struct comedi_cmd cmd; + bool copy = false; + + if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) { + rc = -EFAULT; + break; + } + rc = do_cmdtest_ioctl(dev, &cmd, ©, file); + if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd))) + rc = -EFAULT; + break; + } + case COMEDI_INSNLIST: { + struct comedi_insnlist insnlist; + struct comedi_insn *insns = NULL; + + if (copy_from_user(&insnlist, (void __user *)arg, + sizeof(insnlist))) { + rc = -EFAULT; + break; + } + insns = kcalloc(insnlist.n_insns, sizeof(*insns), GFP_KERNEL); + if (!insns) { + rc = -ENOMEM; + break; + } + if (copy_from_user(insns, insnlist.insns, + sizeof(*insns) * insnlist.n_insns)) { + rc = -EFAULT; + kfree(insns); + break; + } + rc = do_insnlist_ioctl(dev, insns, insnlist.n_insns, file); + kfree(insns); + break; + } + case COMEDI_INSN: { + struct comedi_insn insn; + + if (copy_from_user(&insn, (void __user *)arg, sizeof(insn))) + rc = -EFAULT; + else + rc = do_insn_ioctl(dev, &insn, file); + break; + } + case COMEDI_POLL: + rc = do_poll_ioctl(dev, arg, file); + break; + case COMEDI_SETRSUBD: + rc = do_setrsubd_ioctl(dev, arg, file); + break; + case COMEDI_SETWSUBD: + rc = do_setwsubd_ioctl(dev, arg, file); + break; + default: + rc = -ENOTTY; + break; + } + +done: + mutex_unlock(&dev->mutex); + return rc; +} + +static void comedi_vm_open(struct vm_area_struct *area) +{ + struct comedi_buf_map *bm; + + bm = area->vm_private_data; + comedi_buf_map_get(bm); +} + +static void comedi_vm_close(struct vm_area_struct *area) +{ + struct comedi_buf_map *bm; + + bm = area->vm_private_data; + comedi_buf_map_put(bm); +} + +static int comedi_vm_access(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write) +{ + struct comedi_buf_map *bm = vma->vm_private_data; + unsigned long offset = + addr - vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT); + + if (len < 0) + return -EINVAL; + if (len > vma->vm_end - addr) + len = vma->vm_end - addr; + return comedi_buf_map_access(bm, offset, buf, len, write); +} + +static const struct vm_operations_struct comedi_vm_ops = { + .open = comedi_vm_open, + .close = comedi_vm_close, + .access = comedi_vm_access, +}; + +static int comedi_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi_subdevice *s; + struct comedi_async *async; + struct comedi_buf_map *bm = NULL; + struct comedi_buf_page *buf; + unsigned long start = vma->vm_start; + unsigned long size; + int n_pages; + int i; + int retval = 0; + + /* + * 'trylock' avoids circular dependency with current->mm->mmap_lock + * and down-reading &dev->attach_lock should normally succeed without + * contention unless the device is in the process of being attached + * or detached. + */ + if (!down_read_trylock(&dev->attach_lock)) + return -EAGAIN; + + if (!dev->attached) { + dev_dbg(dev->class_dev, "no driver attached\n"); + retval = -ENODEV; + goto done; + } + + if (vma->vm_flags & VM_WRITE) + s = comedi_file_write_subdevice(file); + else + s = comedi_file_read_subdevice(file); + if (!s) { + retval = -EINVAL; + goto done; + } + + async = s->async; + if (!async) { + retval = -EINVAL; + goto done; + } + + if (vma->vm_pgoff != 0) { + dev_dbg(dev->class_dev, "mmap() offset must be 0.\n"); + retval = -EINVAL; + goto done; + } + + size = vma->vm_end - vma->vm_start; + if (size > async->prealloc_bufsz) { + retval = -EFAULT; + goto done; + } + if (offset_in_page(size)) { + retval = -EFAULT; + goto done; + } + + n_pages = vma_pages(vma); + + /* get reference to current buf map (if any) */ + bm = comedi_buf_map_from_subdev_get(s); + if (!bm || n_pages > bm->n_pages) { + retval = -EINVAL; + goto done; + } + if (bm->dma_dir != DMA_NONE) { + /* + * DMA buffer was allocated as a single block. + * Address is in page_list[0]. + */ + buf = &bm->page_list[0]; + retval = dma_mmap_coherent(bm->dma_hw_dev, vma, buf->virt_addr, + buf->dma_addr, n_pages * PAGE_SIZE); + } else { + for (i = 0; i < n_pages; ++i) { + unsigned long pfn; + + buf = &bm->page_list[i]; + pfn = page_to_pfn(virt_to_page(buf->virt_addr)); + retval = remap_pfn_range(vma, start, pfn, PAGE_SIZE, + PAGE_SHARED); + if (retval) + break; + + start += PAGE_SIZE; + } + } + + if (retval == 0) { + vma->vm_ops = &comedi_vm_ops; + vma->vm_private_data = bm; + + vma->vm_ops->open(vma); + } + +done: + up_read(&dev->attach_lock); + comedi_buf_map_put(bm); /* put reference to buf map - okay if NULL */ + return retval; +} + +static __poll_t comedi_poll(struct file *file, poll_table *wait) +{ + __poll_t mask = 0; + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi_subdevice *s, *s_read; + + down_read(&dev->attach_lock); + + if (!dev->attached) { + dev_dbg(dev->class_dev, "no driver attached\n"); + goto done; + } + + s = comedi_file_read_subdevice(file); + s_read = s; + if (s && s->async) { + poll_wait(file, &s->async->wait_head, wait); + if (s->busy != file || !comedi_is_subdevice_running(s) || + (s->async->cmd.flags & CMDF_WRITE) || + comedi_buf_read_n_available(s) > 0) + mask |= EPOLLIN | EPOLLRDNORM; + } + + s = comedi_file_write_subdevice(file); + if (s && s->async) { + unsigned int bps = comedi_bytes_per_sample(s); + + if (s != s_read) + poll_wait(file, &s->async->wait_head, wait); + if (s->busy != file || !comedi_is_subdevice_running(s) || + !(s->async->cmd.flags & CMDF_WRITE) || + comedi_buf_write_n_available(s) >= bps) + mask |= EPOLLOUT | EPOLLWRNORM; + } + +done: + up_read(&dev->attach_lock); + return mask; +} + +static ssize_t comedi_write(struct file *file, const char __user *buf, + size_t nbytes, loff_t *offset) +{ + struct comedi_subdevice *s; + struct comedi_async *async; + unsigned int n, m; + ssize_t count = 0; + int retval = 0; + DECLARE_WAITQUEUE(wait, current); + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + bool become_nonbusy = false; + bool attach_locked; + unsigned int old_detach_count; + + /* Protect against device detachment during operation. */ + down_read(&dev->attach_lock); + attach_locked = true; + old_detach_count = dev->detach_count; + + if (!dev->attached) { + dev_dbg(dev->class_dev, "no driver attached\n"); + retval = -ENODEV; + goto out; + } + + s = comedi_file_write_subdevice(file); + if (!s || !s->async) { + retval = -EIO; + goto out; + } + + async = s->async; + if (s->busy != file || !(async->cmd.flags & CMDF_WRITE)) { + retval = -EINVAL; + goto out; + } + + add_wait_queue(&async->wait_head, &wait); + while (count == 0 && !retval) { + unsigned int runflags; + unsigned int wp, n1, n2; + + set_current_state(TASK_INTERRUPTIBLE); + + runflags = comedi_get_subdevice_runflags(s); + if (!comedi_is_runflags_running(runflags)) { + if (comedi_is_runflags_in_error(runflags)) + retval = -EPIPE; + if (retval || nbytes) + become_nonbusy = true; + break; + } + if (nbytes == 0) + break; + + /* Allocate all free buffer space. */ + comedi_buf_write_alloc(s, async->prealloc_bufsz); + m = comedi_buf_write_n_allocated(s); + n = min_t(size_t, m, nbytes); + + if (n == 0) { + if (file->f_flags & O_NONBLOCK) { + retval = -EAGAIN; + break; + } + schedule(); + if (signal_pending(current)) { + retval = -ERESTARTSYS; + break; + } + if (s->busy != file || + !(async->cmd.flags & CMDF_WRITE)) { + retval = -EINVAL; + break; + } + continue; + } + + set_current_state(TASK_RUNNING); + wp = async->buf_write_ptr; + n1 = min(n, async->prealloc_bufsz - wp); + n2 = n - n1; + m = copy_from_user(async->prealloc_buf + wp, buf, n1); + if (m) + m += n2; + else if (n2) + m = copy_from_user(async->prealloc_buf, buf + n1, n2); + if (m) { + n -= m; + retval = -EFAULT; + } + comedi_buf_write_free(s, n); + + count += n; + nbytes -= n; + + buf += n; + } + remove_wait_queue(&async->wait_head, &wait); + set_current_state(TASK_RUNNING); + if (become_nonbusy && count == 0) { + struct comedi_subdevice *new_s; + + /* + * To avoid deadlock, cannot acquire dev->mutex + * while dev->attach_lock is held. + */ + up_read(&dev->attach_lock); + attach_locked = false; + mutex_lock(&dev->mutex); + /* + * Check device hasn't become detached behind our back. + * Checking dev->detach_count is unchanged ought to be + * sufficient (unless there have been 2**32 detaches in the + * meantime!), but check the subdevice pointer as well just in + * case. + * + * Also check the subdevice is still in a suitable state to + * become non-busy in case it changed behind our back. + */ + new_s = comedi_file_write_subdevice(file); + if (dev->attached && old_detach_count == dev->detach_count && + s == new_s && new_s->async == async && s->busy == file && + (async->cmd.flags & CMDF_WRITE) && + !comedi_is_subdevice_running(s)) + do_become_nonbusy(dev, s); + mutex_unlock(&dev->mutex); + } +out: + if (attach_locked) + up_read(&dev->attach_lock); + + return count ? count : retval; +} + +static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, + loff_t *offset) +{ + struct comedi_subdevice *s; + struct comedi_async *async; + unsigned int n, m; + ssize_t count = 0; + int retval = 0; + DECLARE_WAITQUEUE(wait, current); + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + unsigned int old_detach_count; + bool become_nonbusy = false; + bool attach_locked; + + /* Protect against device detachment during operation. */ + down_read(&dev->attach_lock); + attach_locked = true; + old_detach_count = dev->detach_count; + + if (!dev->attached) { + dev_dbg(dev->class_dev, "no driver attached\n"); + retval = -ENODEV; + goto out; + } + + s = comedi_file_read_subdevice(file); + if (!s || !s->async) { + retval = -EIO; + goto out; + } + + async = s->async; + if (s->busy != file || (async->cmd.flags & CMDF_WRITE)) { + retval = -EINVAL; + goto out; + } + + add_wait_queue(&async->wait_head, &wait); + while (count == 0 && !retval) { + unsigned int rp, n1, n2; + + set_current_state(TASK_INTERRUPTIBLE); + + m = comedi_buf_read_n_available(s); + n = min_t(size_t, m, nbytes); + + if (n == 0) { + unsigned int runflags = + comedi_get_subdevice_runflags(s); + + if (!comedi_is_runflags_running(runflags)) { + if (comedi_is_runflags_in_error(runflags)) + retval = -EPIPE; + if (retval || nbytes) + become_nonbusy = true; + break; + } + if (nbytes == 0) + break; + if (file->f_flags & O_NONBLOCK) { + retval = -EAGAIN; + break; + } + schedule(); + if (signal_pending(current)) { + retval = -ERESTARTSYS; + break; + } + if (s->busy != file || + (async->cmd.flags & CMDF_WRITE)) { + retval = -EINVAL; + break; + } + continue; + } + + set_current_state(TASK_RUNNING); + rp = async->buf_read_ptr; + n1 = min(n, async->prealloc_bufsz - rp); + n2 = n - n1; + m = copy_to_user(buf, async->prealloc_buf + rp, n1); + if (m) + m += n2; + else if (n2) + m = copy_to_user(buf + n1, async->prealloc_buf, n2); + if (m) { + n -= m; + retval = -EFAULT; + } + + comedi_buf_read_alloc(s, n); + comedi_buf_read_free(s, n); + + count += n; + nbytes -= n; + + buf += n; + } + remove_wait_queue(&async->wait_head, &wait); + set_current_state(TASK_RUNNING); + if (become_nonbusy && count == 0) { + struct comedi_subdevice *new_s; + + /* + * To avoid deadlock, cannot acquire dev->mutex + * while dev->attach_lock is held. + */ + up_read(&dev->attach_lock); + attach_locked = false; + mutex_lock(&dev->mutex); + /* + * Check device hasn't become detached behind our back. + * Checking dev->detach_count is unchanged ought to be + * sufficient (unless there have been 2**32 detaches in the + * meantime!), but check the subdevice pointer as well just in + * case. + * + * Also check the subdevice is still in a suitable state to + * become non-busy in case it changed behind our back. + */ + new_s = comedi_file_read_subdevice(file); + if (dev->attached && old_detach_count == dev->detach_count && + s == new_s && new_s->async == async && s->busy == file && + !(async->cmd.flags & CMDF_WRITE) && + !comedi_is_subdevice_running(s) && + comedi_buf_read_n_available(s) == 0) + do_become_nonbusy(dev, s); + mutex_unlock(&dev->mutex); + } +out: + if (attach_locked) + up_read(&dev->attach_lock); + + return count ? count : retval; +} + +static int comedi_open(struct inode *inode, struct file *file) +{ + const unsigned int minor = iminor(inode); + struct comedi_file *cfp; + struct comedi_device *dev = comedi_dev_get_from_minor(minor); + int rc; + + if (!dev) { + pr_debug("invalid minor number\n"); + return -ENODEV; + } + + cfp = kzalloc(sizeof(*cfp), GFP_KERNEL); + if (!cfp) { + comedi_dev_put(dev); + return -ENOMEM; + } + + cfp->dev = dev; + + mutex_lock(&dev->mutex); + if (!dev->attached && !capable(CAP_SYS_ADMIN)) { + dev_dbg(dev->class_dev, "not attached and not CAP_SYS_ADMIN\n"); + rc = -ENODEV; + goto out; + } + if (dev->attached && dev->use_count == 0) { + if (!try_module_get(dev->driver->module)) { + rc = -ENXIO; + goto out; + } + if (dev->open) { + rc = dev->open(dev); + if (rc < 0) { + module_put(dev->driver->module); + goto out; + } + } + } + + dev->use_count++; + file->private_data = cfp; + comedi_file_reset(file); + rc = 0; + +out: + mutex_unlock(&dev->mutex); + if (rc) { + comedi_dev_put(dev); + kfree(cfp); + } + return rc; +} + +static int comedi_fasync(int fd, struct file *file, int on) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + + return fasync_helper(fd, file, on, &dev->async_queue); +} + +static int comedi_close(struct inode *inode, struct file *file) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi_subdevice *s = NULL; + int i; + + mutex_lock(&dev->mutex); + + if (dev->subdevices) { + for (i = 0; i < dev->n_subdevices; i++) { + s = &dev->subdevices[i]; + + if (s->busy == file) + do_cancel(dev, s); + if (s->lock == file) + s->lock = NULL; + } + } + if (dev->attached && dev->use_count == 1) { + if (dev->close) + dev->close(dev); + module_put(dev->driver->module); + } + + dev->use_count--; + + mutex_unlock(&dev->mutex); + comedi_dev_put(dev); + kfree(cfp); + + return 0; +} + +#ifdef CONFIG_COMPAT + +#define COMEDI32_CHANINFO _IOR(CIO, 3, struct comedi32_chaninfo_struct) +#define COMEDI32_RANGEINFO _IOR(CIO, 8, struct comedi32_rangeinfo_struct) +/* + * N.B. COMEDI32_CMD and COMEDI_CMD ought to use _IOWR, not _IOR. + * It's too late to change it now, but it only affects the command number. + */ +#define COMEDI32_CMD _IOR(CIO, 9, struct comedi32_cmd_struct) +/* + * N.B. COMEDI32_CMDTEST and COMEDI_CMDTEST ought to use _IOWR, not _IOR. + * It's too late to change it now, but it only affects the command number. + */ +#define COMEDI32_CMDTEST _IOR(CIO, 10, struct comedi32_cmd_struct) +#define COMEDI32_INSNLIST _IOR(CIO, 11, struct comedi32_insnlist_struct) +#define COMEDI32_INSN _IOR(CIO, 12, struct comedi32_insn_struct) + +struct comedi32_chaninfo_struct { + unsigned int subdev; + compat_uptr_t maxdata_list; /* 32-bit 'unsigned int *' */ + compat_uptr_t flaglist; /* 32-bit 'unsigned int *' */ + compat_uptr_t rangelist; /* 32-bit 'unsigned int *' */ + unsigned int unused[4]; +}; + +struct comedi32_rangeinfo_struct { + unsigned int range_type; + compat_uptr_t range_ptr; /* 32-bit 'void *' */ +}; + +struct comedi32_cmd_struct { + unsigned int subdev; + unsigned int flags; + unsigned int start_src; + unsigned int start_arg; + unsigned int scan_begin_src; + unsigned int scan_begin_arg; + unsigned int convert_src; + unsigned int convert_arg; + unsigned int scan_end_src; + unsigned int scan_end_arg; + unsigned int stop_src; + unsigned int stop_arg; + compat_uptr_t chanlist; /* 32-bit 'unsigned int *' */ + unsigned int chanlist_len; + compat_uptr_t data; /* 32-bit 'short *' */ + unsigned int data_len; +}; + +struct comedi32_insn_struct { + unsigned int insn; + unsigned int n; + compat_uptr_t data; /* 32-bit 'unsigned int *' */ + unsigned int subdev; + unsigned int chanspec; + unsigned int unused[3]; +}; + +struct comedi32_insnlist_struct { + unsigned int n_insns; + compat_uptr_t insns; /* 32-bit 'struct comedi_insn *' */ +}; + +/* Handle 32-bit COMEDI_CHANINFO ioctl. */ +static int compat_chaninfo(struct file *file, unsigned long arg) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi32_chaninfo_struct chaninfo32; + struct comedi_chaninfo chaninfo; + int err; + + if (copy_from_user(&chaninfo32, compat_ptr(arg), sizeof(chaninfo32))) + return -EFAULT; + + memset(&chaninfo, 0, sizeof(chaninfo)); + chaninfo.subdev = chaninfo32.subdev; + chaninfo.maxdata_list = compat_ptr(chaninfo32.maxdata_list); + chaninfo.flaglist = compat_ptr(chaninfo32.flaglist); + chaninfo.rangelist = compat_ptr(chaninfo32.rangelist); + + mutex_lock(&dev->mutex); + err = do_chaninfo_ioctl(dev, &chaninfo); + mutex_unlock(&dev->mutex); + return err; +} + +/* Handle 32-bit COMEDI_RANGEINFO ioctl. */ +static int compat_rangeinfo(struct file *file, unsigned long arg) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi32_rangeinfo_struct rangeinfo32; + struct comedi_rangeinfo rangeinfo; + int err; + + if (copy_from_user(&rangeinfo32, compat_ptr(arg), sizeof(rangeinfo32))) + return -EFAULT; + memset(&rangeinfo, 0, sizeof(rangeinfo)); + rangeinfo.range_type = rangeinfo32.range_type; + rangeinfo.range_ptr = compat_ptr(rangeinfo32.range_ptr); + + mutex_lock(&dev->mutex); + err = do_rangeinfo_ioctl(dev, &rangeinfo); + mutex_unlock(&dev->mutex); + return err; +} + +/* Copy 32-bit cmd structure to native cmd structure. */ +static int get_compat_cmd(struct comedi_cmd *cmd, + struct comedi32_cmd_struct __user *cmd32) +{ + struct comedi32_cmd_struct v32; + + if (copy_from_user(&v32, cmd32, sizeof(v32))) + return -EFAULT; + + cmd->subdev = v32.subdev; + cmd->flags = v32.flags; + cmd->start_src = v32.start_src; + cmd->start_arg = v32.start_arg; + cmd->scan_begin_src = v32.scan_begin_src; + cmd->scan_begin_arg = v32.scan_begin_arg; + cmd->convert_src = v32.convert_src; + cmd->convert_arg = v32.convert_arg; + cmd->scan_end_src = v32.scan_end_src; + cmd->scan_end_arg = v32.scan_end_arg; + cmd->stop_src = v32.stop_src; + cmd->stop_arg = v32.stop_arg; + cmd->chanlist = (unsigned int __force *)compat_ptr(v32.chanlist); + cmd->chanlist_len = v32.chanlist_len; + cmd->data = compat_ptr(v32.data); + cmd->data_len = v32.data_len; + return 0; +} + +/* Copy native cmd structure to 32-bit cmd structure. */ +static int put_compat_cmd(struct comedi32_cmd_struct __user *cmd32, + struct comedi_cmd *cmd) +{ + struct comedi32_cmd_struct v32; + + memset(&v32, 0, sizeof(v32)); + v32.subdev = cmd->subdev; + v32.flags = cmd->flags; + v32.start_src = cmd->start_src; + v32.start_arg = cmd->start_arg; + v32.scan_begin_src = cmd->scan_begin_src; + v32.scan_begin_arg = cmd->scan_begin_arg; + v32.convert_src = cmd->convert_src; + v32.convert_arg = cmd->convert_arg; + v32.scan_end_src = cmd->scan_end_src; + v32.scan_end_arg = cmd->scan_end_arg; + v32.stop_src = cmd->stop_src; + v32.stop_arg = cmd->stop_arg; + /* Assume chanlist pointer is unchanged. */ + v32.chanlist = ptr_to_compat((unsigned int __user *)cmd->chanlist); + v32.chanlist_len = cmd->chanlist_len; + v32.data = ptr_to_compat(cmd->data); + v32.data_len = cmd->data_len; + if (copy_to_user(cmd32, &v32, sizeof(v32))) + return -EFAULT; + return 0; +} + +/* Handle 32-bit COMEDI_CMD ioctl. */ +static int compat_cmd(struct file *file, unsigned long arg) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi_cmd cmd; + bool copy = false; + int rc, err; + + rc = get_compat_cmd(&cmd, compat_ptr(arg)); + if (rc) + return rc; + + mutex_lock(&dev->mutex); + rc = do_cmd_ioctl(dev, &cmd, ©, file); + mutex_unlock(&dev->mutex); + if (copy) { + /* Special case: copy cmd back to user. */ + err = put_compat_cmd(compat_ptr(arg), &cmd); + if (err) + rc = err; + } + return rc; +} + +/* Handle 32-bit COMEDI_CMDTEST ioctl. */ +static int compat_cmdtest(struct file *file, unsigned long arg) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi_cmd cmd; + bool copy = false; + int rc, err; + + rc = get_compat_cmd(&cmd, compat_ptr(arg)); + if (rc) + return rc; + + mutex_lock(&dev->mutex); + rc = do_cmdtest_ioctl(dev, &cmd, ©, file); + mutex_unlock(&dev->mutex); + if (copy) { + err = put_compat_cmd(compat_ptr(arg), &cmd); + if (err) + rc = err; + } + return rc; +} + +/* Copy 32-bit insn structure to native insn structure. */ +static int get_compat_insn(struct comedi_insn *insn, + struct comedi32_insn_struct __user *insn32) +{ + struct comedi32_insn_struct v32; + + /* Copy insn structure. Ignore the unused members. */ + if (copy_from_user(&v32, insn32, sizeof(v32))) + return -EFAULT; + memset(insn, 0, sizeof(*insn)); + insn->insn = v32.insn; + insn->n = v32.n; + insn->data = compat_ptr(v32.data); + insn->subdev = v32.subdev; + insn->chanspec = v32.chanspec; + return 0; +} + +/* Handle 32-bit COMEDI_INSNLIST ioctl. */ +static int compat_insnlist(struct file *file, unsigned long arg) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi32_insnlist_struct insnlist32; + struct comedi32_insn_struct __user *insn32; + struct comedi_insn *insns; + unsigned int n; + int rc; + + if (copy_from_user(&insnlist32, compat_ptr(arg), sizeof(insnlist32))) + return -EFAULT; + + insns = kcalloc(insnlist32.n_insns, sizeof(*insns), GFP_KERNEL); + if (!insns) + return -ENOMEM; + + /* Copy insn structures. */ + insn32 = compat_ptr(insnlist32.insns); + for (n = 0; n < insnlist32.n_insns; n++) { + rc = get_compat_insn(insns + n, insn32 + n); + if (rc) { + kfree(insns); + return rc; + } + } + + mutex_lock(&dev->mutex); + rc = do_insnlist_ioctl(dev, insns, insnlist32.n_insns, file); + mutex_unlock(&dev->mutex); + kfree(insns); + return rc; +} + +/* Handle 32-bit COMEDI_INSN ioctl. */ +static int compat_insn(struct file *file, unsigned long arg) +{ + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi_insn insn; + int rc; + + rc = get_compat_insn(&insn, (void __user *)arg); + if (rc) + return rc; + + mutex_lock(&dev->mutex); + rc = do_insn_ioctl(dev, &insn, file); + mutex_unlock(&dev->mutex); + return rc; +} + +/* + * compat_ioctl file operation. + * + * Returns -ENOIOCTLCMD for unrecognised ioctl codes. + */ +static long comedi_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int rc; + + switch (cmd) { + case COMEDI_DEVCONFIG: + case COMEDI_DEVINFO: + case COMEDI_SUBDINFO: + case COMEDI_BUFCONFIG: + case COMEDI_BUFINFO: + /* Just need to translate the pointer argument. */ + arg = (unsigned long)compat_ptr(arg); + rc = comedi_unlocked_ioctl(file, cmd, arg); + break; + case COMEDI_LOCK: + case COMEDI_UNLOCK: + case COMEDI_CANCEL: + case COMEDI_POLL: + case COMEDI_SETRSUBD: + case COMEDI_SETWSUBD: + /* No translation needed. */ + rc = comedi_unlocked_ioctl(file, cmd, arg); + break; + case COMEDI32_CHANINFO: + rc = compat_chaninfo(file, arg); + break; + case COMEDI32_RANGEINFO: + rc = compat_rangeinfo(file, arg); + break; + case COMEDI32_CMD: + rc = compat_cmd(file, arg); + break; + case COMEDI32_CMDTEST: + rc = compat_cmdtest(file, arg); + break; + case COMEDI32_INSNLIST: + rc = compat_insnlist(file, arg); + break; + case COMEDI32_INSN: + rc = compat_insn(file, arg); + break; + default: + rc = -ENOIOCTLCMD; + break; + } + return rc; +} +#else +#define comedi_compat_ioctl NULL +#endif + +static const struct file_operations comedi_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = comedi_unlocked_ioctl, + .compat_ioctl = comedi_compat_ioctl, + .open = comedi_open, + .release = comedi_close, + .read = comedi_read, + .write = comedi_write, + .mmap = comedi_mmap, + .poll = comedi_poll, + .fasync = comedi_fasync, + .llseek = noop_llseek, +}; + +/** + * comedi_event() - Handle events for asynchronous COMEDI command + * @dev: COMEDI device. + * @s: COMEDI subdevice. + * Context: in_interrupt() (usually), @s->spin_lock spin-lock not held. + * + * If an asynchronous COMEDI command is active on the subdevice, process + * any %COMEDI_CB_... event flags that have been set, usually by an + * interrupt handler. These may change the run state of the asynchronous + * command, wake a task, and/or send a %SIGIO signal. + */ +void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s) +{ + struct comedi_async *async = s->async; + unsigned int events; + int si_code = 0; + unsigned long flags; + + spin_lock_irqsave(&s->spin_lock, flags); + + events = async->events; + async->events = 0; + if (!__comedi_is_subdevice_running(s)) { + spin_unlock_irqrestore(&s->spin_lock, flags); + return; + } + + if (events & COMEDI_CB_CANCEL_MASK) + __comedi_clear_subdevice_runflags(s, COMEDI_SRF_RUNNING); + + /* + * Remember if an error event has occurred, so an error can be + * returned the next time the user does a read() or write(). + */ + if (events & COMEDI_CB_ERROR_MASK) + __comedi_set_subdevice_runflags(s, COMEDI_SRF_ERROR); + + if (async->cb_mask & events) { + wake_up_interruptible(&async->wait_head); + si_code = async->cmd.flags & CMDF_WRITE ? POLL_OUT : POLL_IN; + } + + spin_unlock_irqrestore(&s->spin_lock, flags); + + if (si_code) + kill_fasync(&dev->async_queue, SIGIO, si_code); +} +EXPORT_SYMBOL_GPL(comedi_event); + +/* Note: the ->mutex is pre-locked on successful return */ +struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device) +{ + struct comedi_device *dev; + struct device *csdev; + unsigned int i; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return ERR_PTR(-ENOMEM); + comedi_device_init(dev); + comedi_set_hw_dev(dev, hardware_device); + mutex_lock(&dev->mutex); + mutex_lock(&comedi_board_minor_table_lock); + for (i = hardware_device ? comedi_num_legacy_minors : 0; + i < COMEDI_NUM_BOARD_MINORS; ++i) { + if (!comedi_board_minor_table[i]) { + comedi_board_minor_table[i] = dev; + break; + } + } + mutex_unlock(&comedi_board_minor_table_lock); + if (i == COMEDI_NUM_BOARD_MINORS) { + mutex_unlock(&dev->mutex); + comedi_device_cleanup(dev); + comedi_dev_put(dev); + dev_err(hardware_device, + "ran out of minor numbers for board device files\n"); + return ERR_PTR(-EBUSY); + } + dev->minor = i; + csdev = device_create(comedi_class, hardware_device, + MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i", i); + if (!IS_ERR(csdev)) + dev->class_dev = get_device(csdev); + + /* Note: dev->mutex needs to be unlocked by the caller. */ + return dev; +} + +void comedi_release_hardware_device(struct device *hardware_device) +{ + int minor; + struct comedi_device *dev; + + for (minor = comedi_num_legacy_minors; minor < COMEDI_NUM_BOARD_MINORS; + minor++) { + mutex_lock(&comedi_board_minor_table_lock); + dev = comedi_board_minor_table[minor]; + if (dev && dev->hw_dev == hardware_device) { + comedi_board_minor_table[minor] = NULL; + mutex_unlock(&comedi_board_minor_table_lock); + comedi_free_board_dev(dev); + break; + } + mutex_unlock(&comedi_board_minor_table_lock); + } +} + +int comedi_alloc_subdevice_minor(struct comedi_subdevice *s) +{ + struct comedi_device *dev = s->device; + struct device *csdev; + unsigned int i; + + mutex_lock(&comedi_subdevice_minor_table_lock); + for (i = 0; i < COMEDI_NUM_SUBDEVICE_MINORS; ++i) { + if (!comedi_subdevice_minor_table[i]) { + comedi_subdevice_minor_table[i] = s; + break; + } + } + mutex_unlock(&comedi_subdevice_minor_table_lock); + if (i == COMEDI_NUM_SUBDEVICE_MINORS) { + dev_err(dev->class_dev, + "ran out of minor numbers for subdevice files\n"); + return -EBUSY; + } + i += COMEDI_NUM_BOARD_MINORS; + s->minor = i; + csdev = device_create(comedi_class, dev->class_dev, + MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i_subd%i", + dev->minor, s->index); + if (!IS_ERR(csdev)) + s->class_dev = csdev; + + return 0; +} + +void comedi_free_subdevice_minor(struct comedi_subdevice *s) +{ + unsigned int i; + + if (!s) + return; + if (s->minor < COMEDI_NUM_BOARD_MINORS || + s->minor >= COMEDI_NUM_MINORS) + return; + + i = s->minor - COMEDI_NUM_BOARD_MINORS; + mutex_lock(&comedi_subdevice_minor_table_lock); + if (s == comedi_subdevice_minor_table[i]) + comedi_subdevice_minor_table[i] = NULL; + mutex_unlock(&comedi_subdevice_minor_table_lock); + if (s->class_dev) { + device_destroy(comedi_class, MKDEV(COMEDI_MAJOR, s->minor)); + s->class_dev = NULL; + } +} + +static void comedi_cleanup_board_minors(void) +{ + struct comedi_device *dev; + unsigned int i; + + for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { + dev = comedi_clear_board_minor(i); + comedi_free_board_dev(dev); + } +} + +static int __init comedi_init(void) +{ + int i; + int retval; + + pr_info("version " COMEDI_RELEASE " - http://www.comedi.org\n"); + + if (comedi_num_legacy_minors > COMEDI_NUM_BOARD_MINORS) { + pr_err("invalid value for module parameter \"comedi_num_legacy_minors\". Valid values are 0 through %i.\n", + COMEDI_NUM_BOARD_MINORS); + return -EINVAL; + } + + retval = register_chrdev_region(MKDEV(COMEDI_MAJOR, 0), + COMEDI_NUM_MINORS, "comedi"); + if (retval) + return retval; + + cdev_init(&comedi_cdev, &comedi_fops); + comedi_cdev.owner = THIS_MODULE; + + retval = kobject_set_name(&comedi_cdev.kobj, "comedi"); + if (retval) + goto out_unregister_chrdev_region; + + retval = cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0), + COMEDI_NUM_MINORS); + if (retval) + goto out_unregister_chrdev_region; + + comedi_class = class_create(THIS_MODULE, "comedi"); + if (IS_ERR(comedi_class)) { + retval = PTR_ERR(comedi_class); + pr_err("failed to create class\n"); + goto out_cdev_del; + } + + comedi_class->dev_groups = comedi_dev_groups; + + /* create devices files for legacy/manual use */ + for (i = 0; i < comedi_num_legacy_minors; i++) { + struct comedi_device *dev; + + dev = comedi_alloc_board_minor(NULL); + if (IS_ERR(dev)) { + retval = PTR_ERR(dev); + goto out_cleanup_board_minors; + } + /* comedi_alloc_board_minor() locked the mutex */ + lockdep_assert_held(&dev->mutex); + mutex_unlock(&dev->mutex); + } + + /* XXX requires /proc interface */ + comedi_proc_init(); + + return 0; + +out_cleanup_board_minors: + comedi_cleanup_board_minors(); + class_destroy(comedi_class); +out_cdev_del: + cdev_del(&comedi_cdev); +out_unregister_chrdev_region: + unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS); + return retval; +} +module_init(comedi_init); + +static void __exit comedi_cleanup(void) +{ + comedi_cleanup_board_minors(); + class_destroy(comedi_class); + cdev_del(&comedi_cdev); + unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS); + + comedi_proc_cleanup(); +} +module_exit(comedi_cleanup); + +MODULE_AUTHOR("https://www.comedi.org"); +MODULE_DESCRIPTION("Comedi core module"); +MODULE_LICENSE("GPL"); |