dax: set instance lifespan from prepare to reset

At present, dax instance is initialized and allocated inner buffer
on module_init(), and released on module_free(). The memory
requirement for the inner buffer per instance is quite large.

The existing implementation has 2 pipelines containing dax. Even
though the host is restricted from processing stream on both
pipelines simultaneously, they may coexist with each other under some
circumstances e.g. the interim when switching PCM device from one to
the other, which may drain out the memory.

This commit changes the timing of instance allocation/deallocation to
module_prepare()/reset() respectively. That is, dax instance only
occupies the inner buffer memory when processing.

Signed-off-by: Johny Lin <johnylin@google.com>

Author: johnylin76

src/audio/module_adapter/module/dolby/dax.c

@@ -181,6 +181,51 @@ static void dax_buffer_produce(struct dax_buffer *dax_buff, uint32_t bytes)
 	dax_buff->free = dax_buff->size - dax_buff->avail;
 }
 
+static void destroy_instance(struct processing_module *mod)
+{
+	struct sof_dax *dax_ctx = module_get_private_data(mod);
+
+	dax_free(dax_ctx); /* free internal dax instance in dax_ctx */
+	dax_buffer_release(mod, &dax_ctx->persist_buffer);
+	dax_buffer_release(mod, &dax_ctx->scratch_buffer);
+}
+
+static int establish_instance(struct processing_module *mod)
+{
+	int ret = 0;
+	struct comp_dev *dev = mod->dev;
+	struct sof_dax *dax_ctx = module_get_private_data(mod);
+	uint32_t persist_sz;
+	uint32_t scratch_sz;
+
+	persist_sz = dax_query_persist_memory(dax_ctx);
+	if (dax_buffer_alloc(mod, &dax_ctx->persist_buffer, persist_sz) != 0) {
+		comp_err(dev, "allocate %u bytes failed for persist", persist_sz);
+		ret = -ENOMEM;
+		goto err;
+	}
+	scratch_sz = dax_query_scratch_memory(dax_ctx);
+	if (dax_buffer_alloc(mod, &dax_ctx->scratch_buffer, scratch_sz) != 0) {
+		comp_err(dev, "allocate %u bytes failed for scratch", scratch_sz);
+		ret = -ENOMEM;
+		goto err;
+	}
+	ret = dax_init(dax_ctx);
+	if (ret != 0) {
+		comp_err(dev, "dax instance initialization failed, ret %d", ret);
+		goto err;
+	}
+	dax_ctx->update_flags |= DAX_ENABLE_MASK;
+
+	comp_info(dev, "allocated: persist %u, scratch %u. version: %s",
+			  persist_sz, scratch_sz, dax_get_version());
+	return 0;
+
+err:
+	destroy_instance(mod);
+	return ret;
+}
+
 static int set_tuning_file(struct processing_module *mod, void *value, uint32_t size)
 {
 	int ret = 0;
@@ -463,17 +508,21 @@ static void check_and_update_settings(struct processing_module *mod)
 	}
 }
 
+static int sof_dax_reset(struct processing_module *mod) {
+	/* dax instance will be established on prepare(), and destroyed on reset() */
+	destroy_instance(mod);
+	dax_buffer_release(mod, &dax_ctx->input_buffer);
+	dax_buffer_release(mod, &dax_ctx->output_buffer);
+	return 0;
+}
+
 static int sof_dax_free(struct processing_module *mod)
 {
 	struct sof_dax *dax_ctx = module_get_private_data(mod);
 
 	if (dax_ctx) {
-		dax_free(dax_ctx);
-		dax_buffer_release(mod, &dax_ctx->persist_buffer);
-		dax_buffer_release(mod, &dax_ctx->scratch_buffer);
+		sof_dax_reset(mod);
 		dax_buffer_release(mod, &dax_ctx->tuning_file_buffer);
-		dax_buffer_release(mod, &dax_ctx->input_buffer);
-		dax_buffer_release(mod, &dax_ctx->output_buffer);
 		mod_data_blob_handler_free(mod, dax_ctx->blob_handler);
 		dax_ctx->blob_handler = NULL;
 		mod_free(mod, dax_ctx);
@@ -484,12 +533,9 @@ static int sof_dax_free(struct processing_module *mod)
 
 static int sof_dax_init(struct processing_module *mod)
 {
-	int ret;
 	struct comp_dev *dev = mod->dev;
 	struct module_data *md = &mod->priv;
 	struct sof_dax *dax_ctx;
-	uint32_t persist_sz;
-	uint32_t scratch_sz;
 
 	md->private = mod_zalloc(mod, sizeof(struct sof_dax));
 	if (!md->private) {
@@ -509,35 +555,12 @@ static int sof_dax_init(struct processing_module *mod)
 	dax_ctx->blob_handler = mod_data_blob_handler_new(mod);
 	if (!dax_ctx->blob_handler) {
 		comp_err(dev, "create blob handler failed");
-		ret = -ENOMEM;
-		goto err;
-	}
-
-	persist_sz = dax_query_persist_memory(dax_ctx);
-	if (dax_buffer_alloc(mod, &dax_ctx->persist_buffer, persist_sz) != 0) {
-		comp_err(dev, "allocate %u bytes failed for persist", persist_sz);
-		ret = -ENOMEM;
-		goto err;
-	}
-	scratch_sz = dax_query_scratch_memory(dax_ctx);
-	if (dax_buffer_alloc(mod, &dax_ctx->scratch_buffer, scratch_sz) != 0) {
-		comp_err(dev, "allocate %u bytes failed for scratch", scratch_sz);
-		ret = -ENOMEM;
-		goto err;
-	}
-	ret = dax_init(dax_ctx);
-	if (ret != 0) {
-		comp_err(dev, "dax instance initialization failed, ret %d", ret);
-		goto err;
+		mod_free(mod, dax_ctx);
+		module_set_private_data(mod, NULL);
+		return -ENOMEM;
 	}
 
-	comp_info(dev, "allocated: persist %u, scratch %u. version: %s",
-		  persist_sz, scratch_sz, dax_get_version());
 	return 0;
-
-err:
-	sof_dax_free(mod);
-	return ret;
 }
 
 static int check_media_format(struct processing_module *mod)
@@ -631,6 +654,11 @@ static int sof_dax_prepare(struct processing_module *mod, struct sof_source **so
 	if (ret != 0)
 		return ret;
 
+	/* dax instance will be established on prepare(), and destroyed on reset() */
+	ret = establish_instance(mod);
+	if (ret != 0)
+		return ret;
+
 	dax_ctx->sof_period_bytes = dev->frames *
 		dax_ctx->output_media_format.num_channels *
 		dax_ctx->output_media_format.bytes_per_sample;
@@ -855,6 +883,7 @@ static const struct module_interface dolby_dax_audio_processing_interface = {
 	.prepare = sof_dax_prepare,
 	.process = sof_dax_process,
 	.set_configuration = sof_dax_set_configuration,
+	.reset = sof_dax_reset,
 	.free = sof_dax_free,
 };