blob: df77b6bf5c641d56da651d46d388fdfcb3c9424e [file] [log] [blame]
// 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 "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 snprintf(buf, PAGE_SIZE, "%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 snprintf(buf, PAGE_SIZE, "%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 snprintf(buf, PAGE_SIZE, "%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 snprintf(buf, PAGE_SIZE, "%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, &copy, 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, &copy, 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++) {