iio: core: move @info_exist_lock to struct iio_dev_opaque

This lock is only of interest to the IIO core, so make it only
visible there.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210426174911.397061-7-jic23@kernel.org

drivers/iio/industrialio-buffer.c

@@ -1150,12 +1150,13 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 		       struct iio_buffer *insert_buffer,
 		       struct iio_buffer *remove_buffer)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 	int ret;
 
 	if (insert_buffer == remove_buffer)
 		return 0;
 
-	mutex_lock(&indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	mutex_lock(&indio_dev->mlock);
 
 	if (insert_buffer && iio_buffer_is_active(insert_buffer))
@@ -1178,7 +1179,7 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 
 out_unlock:
 	mutex_unlock(&indio_dev->mlock);
-	mutex_unlock(&indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }

drivers/iio/industrialio-core.c

@@ -1642,7 +1642,7 @@ struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
 	device_initialize(&indio_dev->dev);
 	iio_device_set_drvdata(indio_dev, (void *)indio_dev);
 	mutex_init(&indio_dev->mlock);
-	mutex_init(&indio_dev->info_exist_lock);
+	mutex_init(&iio_dev_opaque->info_exist_lock);
 	INIT_LIST_HEAD(&iio_dev_opaque->channel_attr_list);
 
 	iio_dev_opaque->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
@@ -1779,7 +1779,7 @@ static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	struct iio_ioctl_handler *h;
 	int ret = -ENODEV;
 
-	mutex_lock(&indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 
 	/**
 	 * The NULL check here is required to prevent crashing when a device
@@ -1799,7 +1799,7 @@ static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		ret = -ENODEV;
 
 out_unlock:
-	mutex_unlock(&indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }
@@ -1938,7 +1938,7 @@ void iio_device_unregister(struct iio_dev *indio_dev)
 {
 	cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
 
-	mutex_lock(&indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 
 	iio_device_unregister_debugfs(indio_dev);
 
@@ -1949,7 +1949,7 @@ void iio_device_unregister(struct iio_dev *indio_dev)
 	iio_device_wakeup_eventset(indio_dev);
 	iio_buffer_wakeup_poll(indio_dev);
 
-	mutex_unlock(&indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	iio_buffers_free_sysfs_and_mask(indio_dev);
 }

drivers/iio/inkern.c

@@ -10,6 +10,7 @@
 #include <linux/of.h>
 
 #include <linux/iio/iio.h>
+#include <linux/iio/iio-opaque.h>
 #include "iio_core.h"
 #include <linux/iio/machine.h>
 #include <linux/iio/driver.h>
@@ -538,9 +539,10 @@ static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
 
 int iio_read_channel_raw(struct iio_channel *chan, int *val)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 	int ret;
 
-	mutex_lock(&chan->indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	if (chan->indio_dev->info == NULL) {
 		ret = -ENODEV;
 		goto err_unlock;
@@ -548,7 +550,7 @@ int iio_read_channel_raw(struct iio_channel *chan, int *val)
 
 	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
 err_unlock:
-	mutex_unlock(&chan->indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }
@@ -556,9 +558,10 @@ EXPORT_SYMBOL_GPL(iio_read_channel_raw);
 
 int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 	int ret;
 
-	mutex_lock(&chan->indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	if (chan->indio_dev->info == NULL) {
 		ret = -ENODEV;
 		goto err_unlock;
@@ -566,7 +569,7 @@ int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
 
 	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
 err_unlock:
-	mutex_unlock(&chan->indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }
@@ -631,9 +634,10 @@ static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
 int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
 	int *processed, unsigned int scale)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 	int ret;
 
-	mutex_lock(&chan->indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	if (chan->indio_dev->info == NULL) {
 		ret = -ENODEV;
 		goto err_unlock;
@@ -642,7 +646,7 @@ int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
 	ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
 							scale);
 err_unlock:
-	mutex_unlock(&chan->indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }
@@ -651,9 +655,10 @@ EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
 int iio_read_channel_attribute(struct iio_channel *chan, int *val, int *val2,
 			       enum iio_chan_info_enum attribute)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 	int ret;
 
-	mutex_lock(&chan->indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	if (chan->indio_dev->info == NULL) {
 		ret = -ENODEV;
 		goto err_unlock;
@@ -661,7 +666,7 @@ int iio_read_channel_attribute(struct iio_channel *chan, int *val, int *val2,
 
 	ret = iio_channel_read(chan, val, val2, attribute);
 err_unlock:
-	mutex_unlock(&chan->indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }
@@ -676,9 +681,10 @@ EXPORT_SYMBOL_GPL(iio_read_channel_offset);
 int iio_read_channel_processed_scale(struct iio_channel *chan, int *val,
 				     unsigned int scale)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 	int ret;
 
-	mutex_lock(&chan->indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	if (chan->indio_dev->info == NULL) {
 		ret = -ENODEV;
 		goto err_unlock;
@@ -699,7 +705,7 @@ int iio_read_channel_processed_scale(struct iio_channel *chan, int *val,
 	}
 
 err_unlock:
-	mutex_unlock(&chan->indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }
@@ -733,9 +739,10 @@ int iio_read_avail_channel_attribute(struct iio_channel *chan,
 				     const int **vals, int *type, int *length,
 				     enum iio_chan_info_enum attribute)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 	int ret;
 
-	mutex_lock(&chan->indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	if (!chan->indio_dev->info) {
 		ret = -ENODEV;
 		goto err_unlock;
@@ -743,7 +750,7 @@ int iio_read_avail_channel_attribute(struct iio_channel *chan,
 
 	ret = iio_channel_read_avail(chan, vals, type, length, attribute);
 err_unlock:
-	mutex_unlock(&chan->indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }
@@ -815,10 +822,11 @@ static int iio_channel_read_max(struct iio_channel *chan,
 
 int iio_read_max_channel_raw(struct iio_channel *chan, int *val)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 	int ret;
 	int type;
 
-	mutex_lock(&chan->indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	if (!chan->indio_dev->info) {
 		ret = -ENODEV;
 		goto err_unlock;
@@ -826,7 +834,7 @@ int iio_read_max_channel_raw(struct iio_channel *chan, int *val)
 
 	ret = iio_channel_read_max(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
 err_unlock:
-	mutex_unlock(&chan->indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }
@@ -834,10 +842,11 @@ EXPORT_SYMBOL_GPL(iio_read_max_channel_raw);
 
 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 	int ret = 0;
 	/* Need to verify underlying driver has not gone away */
 
-	mutex_lock(&chan->indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	if (chan->indio_dev->info == NULL) {
 		ret = -ENODEV;
 		goto err_unlock;
@@ -845,7 +854,7 @@ int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
 
 	*type = chan->channel->type;
 err_unlock:
-	mutex_unlock(&chan->indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }
@@ -861,9 +870,10 @@ static int iio_channel_write(struct iio_channel *chan, int val, int val2,
 int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2,
 				enum iio_chan_info_enum attribute)
 {
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 	int ret;
 
-	mutex_lock(&chan->indio_dev->info_exist_lock);
+	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	if (chan->indio_dev->info == NULL) {
 		ret = -ENODEV;
 		goto err_unlock;
@@ -871,7 +881,7 @@ int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2,
 
 	ret = iio_channel_write(chan, val, val2, attribute);
 err_unlock:
-	mutex_unlock(&chan->indio_dev->info_exist_lock);
+	mutex_unlock(&iio_dev_opaque->info_exist_lock);
 
 	return ret;
 }

include/linux/iio/iio-opaque.h

@@ -8,6 +8,7 @@
  * @indio_dev:			public industrial I/O device information
  * @id:			used to identify device internally
  * @driver_module:		used to make it harder to undercut users
+ * @info_exist_lock:		lock to prevent use during removal
  * @trig_readonly:		mark the current trigger immutable
  * @event_interface:		event chrdevs associated with interrupt lines
  * @attached_buffers:		array of buffers statically attached by the driver
@@ -32,6 +33,7 @@ struct iio_dev_opaque {
 	struct iio_dev			indio_dev;
 	int				id;
 	struct module			*driver_module;
+	struct mutex			info_exist_lock;
 	bool				trig_readonly;
 	struct iio_event_interface	*event_interface;
 	struct iio_buffer		**attached_buffers;

include/linux/iio/iio.h

@@ -510,7 +510,6 @@ struct iio_buffer_setup_ops {
  * @label:              [DRIVER] unique name to identify which device this is
  * @info:		[DRIVER] callbacks and constant info from driver
  * @clock_id:		[INTERN] timestamping clock posix identifier
- * @info_exist_lock:	[INTERN] lock to prevent use during removal
  * @setup_ops:		[DRIVER] callbacks to call before and after buffer
  *			enable/disable
  * @chrdev:		[INTERN] associated character device
@@ -542,7 +541,6 @@ struct iio_dev {
 	const char			*label;
 	const struct iio_info		*info;
 	clockid_t			clock_id;
-	struct mutex			info_exist_lock;
 	const struct iio_buffer_setup_ops	*setup_ops;
 	struct cdev			chrdev;