iio: __iio_update_buffers: Slightly refactor scan mask memory management

Add a small helper function iio_free_scan_mask() that takes a mask and
frees its memory if the scan masks for the device are dynamically
allocated, otherwise does nothing. This means we don't have to open-code
the same check over and over again in __iio_update_buffers.

Also free compound_mask as soon a we are done using it. This constrains its
usage to a specific region of the function will make further refactoring
and splitting the function into smaller sub-parts more easier.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 1f91031aa4602963a1e47cca647df84327d4225a..2afe3dbd8d3d2c5673ee671269d7539418750def 100644 (file)
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -575,6 +575,14 @@ static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
        buffer->access->set_bytes_per_datum(buffer, bytes);
 }
 
+static void iio_free_scan_mask(struct iio_dev *indio_dev,
+       const unsigned long *mask)
+{
+       /* If the mask is dynamically allocated free it, otherwise do nothing */
+       if (!indio_dev->available_scan_masks)
+               kfree(mask);
+}
+
 static int __iio_update_buffers(struct iio_dev *indio_dev,
                       struct iio_buffer *insert_buffer,
                       struct iio_buffer *remove_buffer)
@@ -612,8 +620,7 @@ static int __iio_update_buffers(struct iio_dev *indio_dev,
        /* If no buffers in list, we are done */
        if (list_empty(&indio_dev->buffer_list)) {
                indio_dev->currentmode = INDIO_DIRECT_MODE;
-               if (indio_dev->available_scan_masks == NULL)
-                       kfree(old_mask);
+               iio_free_scan_mask(indio_dev, old_mask);
                return 0;
        }
 
@@ -621,8 +628,7 @@ static int __iio_update_buffers(struct iio_dev *indio_dev,
        compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
                                sizeof(long), GFP_KERNEL);
        if (compound_mask == NULL) {
-               if (indio_dev->available_scan_masks == NULL)
-                       kfree(old_mask);
+               iio_free_scan_mask(indio_dev, old_mask);
                return -ENOMEM;
        }
        indio_dev->scan_timestamp = 0;
@@ -637,6 +643,7 @@ static int __iio_update_buffers(struct iio_dev *indio_dev,
                        iio_scan_mask_match(indio_dev->available_scan_masks,
                                            indio_dev->masklength,
                                            compound_mask);
+               kfree(compound_mask);
                if (indio_dev->active_scan_mask == NULL) {
                        /*
                         * Roll back.
@@ -648,7 +655,6 @@ static int __iio_update_buffers(struct iio_dev *indio_dev,
                                success = -EINVAL;
                        }
                        else {
-                               kfree(compound_mask);
                                ret = -EINVAL;
                                return ret;
                        }
@@ -721,10 +727,7 @@ static int __iio_update_buffers(struct iio_dev *indio_dev,
                }
        }
 
-       if (indio_dev->available_scan_masks)
-               kfree(compound_mask);
-       else
-               kfree(old_mask);
+       iio_free_scan_mask(indio_dev, old_mask);
 
        return success;
 
@@ -736,8 +739,8 @@ error_run_postdisable:
 error_remove_inserted:
        if (insert_buffer)
                iio_buffer_deactivate(insert_buffer);
+       iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask);
        indio_dev->active_scan_mask = old_mask;
-       kfree(compound_mask);
        return ret;
 }