On Thu, 20 Feb 2020 17:03:13 +0200
Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote:
> Currently, when using a 'iio_dmaengine_buffer_alloc()', an matching call to
> 'iio_dmaengine_buffer_free()' must be made.
>
> With this change, this can be avoided by using
> 'devm_iio_dmaengine_buffer_alloc()'. The buffer will get free'd via the
> device's devres handling.
>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
> ---
> .../buffer/industrialio-buffer-dmaengine.c | 70 +++++++++++++++++++
> include/linux/iio/buffer-dmaengine.h | 5 ++
> 2 files changed, 75 insertions(+)
>
> diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> index b129693af0fd..eff89037e3f5 100644
> --- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> +++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> @@ -229,6 +229,76 @@ void iio_dmaengine_buffer_free(struct iio_buffer *buffer)
> }
> EXPORT_SYMBOL_GPL(iio_dmaengine_buffer_free);
>
> +static void __devm_iio_dmaengine_buffer_free(struct device *dev, void *res)
> +{
> + iio_dmaengine_buffer_free(*(struct iio_buffer **)res);
> +}
> +
> +/**
> + * devm_iio_dmaengine_buffer_alloc() - Resource-managed iio_dmaengine_buffer_alloc()
> + * @dev: Parent device for the buffer
> + * @channel: DMA channel name, typically "rx".
> + *
> + * This allocates a new IIO buffer which internally uses the DMAengine framework
> + * to perform its transfers. The parent device will be used to request the DMA
> + * channel.
> + *
> + * Once done using the buffer iio_dmaengine_buffer_free() should be used to
> + * release it.
Umm. It really shouldn't!
> + */
> +struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
> + const char *channel)
> +{
> + struct iio_buffer **bufferp, *buffer;
> +
> + bufferp = devres_alloc(__devm_iio_dmaengine_buffer_free,
> + sizeof(*bufferp), GFP_KERNEL);
> + if (!bufferp)
> + return ERR_PTR(-ENOMEM);
> +
> + buffer = iio_dmaengine_buffer_alloc(dev, channel);
> + if (!IS_ERR(buffer)) {
> + *bufferp = buffer;
> + devres_add(dev, bufferp);
>From a flow point of view I'd prefer.
if (IS_ERR(buffer) {
devres_free(buferp)
return buffer;
}
*bufferp = buffer;
devres_add(dev, bufferp);
return buffer;
> + } else {
> + devres_free(bufferp);
> + }
> +
> + return buffer;
> +}
> +EXPORT_SYMBOL_GPL(devm_iio_dmaengine_buffer_alloc);
> +
> +static int devm_iio_dmaengine_buffer_match(struct device *dev, void *res,
> + void *data)
> +{
> + struct iio_buffer **r = res;
> +
> + if (!r || !*r) {
> + WARN_ON(!r || !*r);
> + return 0;
> + }
> +
> + return *r == data;
> +}
> +
> +/**
> + * devm_iio_dmaengine_buffer_free - iio_dmaengine_buffer_free
> + * @dev: Device this iio_buffer belongs to
> + * @buffer: The iio_buffer associated with the device
> + *
> + * Free buffer allocated with devm_iio_dmaengine_buffer_alloc().
> + */
> +void devm_iio_dmaengine_buffer_free(struct device *dev,
> + struct iio_buffer *buffer)
> +{
> + int rc;
> +
> + rc = devres_release(dev, __devm_iio_dmaengine_buffer_free,
> + devm_iio_dmaengine_buffer_match, buffer);
> + WARN_ON(rc);
> +}
> +EXPORT_SYMBOL_GPL(devm_iio_dmaengine_buffer_free);
> +
> MODULE_AUTHOR("Lars-Peter Clausen <lars@xxxxxxxxxx>");
> MODULE_DESCRIPTION("DMA buffer for the IIO framework");
> MODULE_LICENSE("GPL");
> diff --git a/include/linux/iio/buffer-dmaengine.h b/include/linux/iio/buffer-dmaengine.h
> index b3a57444a886..8dcd973d76c1 100644
> --- a/include/linux/iio/buffer-dmaengine.h
> +++ b/include/linux/iio/buffer-dmaengine.h
> @@ -14,4 +14,9 @@ struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
> const char *channel);
> void iio_dmaengine_buffer_free(struct iio_buffer *buffer);
>
> +struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
> + const char *channel);
> +void devm_iio_dmaengine_buffer_free(struct device *dev,
> + struct iio_buffer *buffer);
Please align parameters with opening bracket where possible.
Thanks,
Jonathan
> +
> #endif
