[alsa-devel] [PATCH 5/7] ALSA: core: Implement compress page allocation and free routines

[Takashi Iwai]

On Tue, 17 Dec 2019 10:58:49 +0100,
Cezary Rojewski wrote:
> 
> Add simple malloc and free methods for memory management for compress
> streams. Based on snd_pcm_lib_malloc_pages and snd_pcm_lib_free_pages
> implementation.

I see no user of these functions in the series.  How these are
supposed to be used?


Takashi

> 
> Signed-off-by: Cezary Rojewski <cezary.rojewski at intel.com>
> Signed-off-by: Divya Prakash <divya1.prakash at intel.com>
> ---
>  include/sound/compress_driver.h |  5 ++++
>  sound/core/compress_offload.c   | 42 +++++++++++++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
> 
> diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
> index 00f633c0c3ba..6ce8effa0b12 100644
> --- a/include/sound/compress_driver.h
> +++ b/include/sound/compress_driver.h
> @@ -67,6 +67,7 @@ struct snd_compr_runtime {
>   * @metadata_set: metadata set flag, true when set
>   * @next_track: has userspace signal next track transition, true when set
>   * @private_data: pointer to DSP private data
> + * @dma_buffer: allocated buffer if any
>   */
>  struct snd_compr_stream {
>  	const char *name;
> @@ -78,6 +79,7 @@ struct snd_compr_stream {
>  	bool metadata_set;
>  	bool next_track;
>  	void *private_data;
> +	struct snd_dma_buffer dma_buffer;
>  };
>  
>  /**
> @@ -212,6 +214,9 @@ snd_compr_set_runtime_buffer(struct snd_compr_stream *stream,
>  	}
>  }
>  
> +int snd_compr_malloc_pages(struct snd_compr_stream *stream, size_t size);
> +int snd_compr_free_pages(struct snd_compr_stream *stream);
> +
>  int snd_compr_stop_error(struct snd_compr_stream *stream,
>  			 snd_pcm_state_t state);
>  
> diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
> index f34ce564d92c..dfb20ceb2d30 100644
> --- a/sound/core/compress_offload.c
> +++ b/sound/core/compress_offload.c
> @@ -488,6 +488,48 @@ snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
>  }
>  #endif /* !COMPR_CODEC_CAPS_OVERFLOW */
>  
> +int snd_compr_malloc_pages(struct snd_compr_stream *stream, size_t size)
> +{
> +	struct snd_dma_buffer *dmab;
> +	int ret;
> +
> +	if (snd_BUG_ON(!(stream) || !(stream)->runtime))
> +		return -EINVAL;
> +	dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
> +	if (!dmab)
> +		return -ENOMEM;
> +	dmab->dev = stream->dma_buffer.dev;
> +	ret = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev, size, dmab);
> +	if (ret < 0) {
> +		kfree(dmab);
> +		return ret;
> +	}
> +
> +	snd_compr_set_runtime_buffer(stream, dmab);
> +	stream->runtime->dma_bytes = size;
> +	return 1;
> +}
> +EXPORT_SYMBOL(snd_compr_malloc_pages);
> +
> +int snd_compr_free_pages(struct snd_compr_stream *stream)
> +{
> +	struct snd_compr_runtime *runtime = stream->runtime;
> +
> +	if (snd_BUG_ON(!(stream) || !(stream)->runtime))
> +		return -EINVAL;
> +	if (!runtime->dma_area)
> +		return 0;
> +	if (runtime->dma_buffer_p != &stream->dma_buffer) {
> +		/* It's a newly allocated buffer. Release it now. */
> +		snd_dma_free_pages(runtime->dma_buffer_p);
> +		kfree(runtime->dma_buffer_p);
> +	}
> +
> +	snd_compr_set_runtime_buffer(stream, NULL);
> +	return 0;
> +}
> +EXPORT_SYMBOL(snd_compr_free_pages);
> +
>  /* revisit this with snd_pcm_preallocate_xxx */
>  static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
>  		struct snd_compr_params *params)
> -- 
> 2.17.1
>