Audio: MDRC: Restructure Multiband DRC for more effective memory allocation

The coefficient allocation for the crossover, emphasis, and deemphasis
filters is combined into a single contiguous memory block with this
check-in.

Benefits include decreased heap fragmentation risk, better cache
performance because of data locality, and less memory allocation overhead.

A significant reduction in the complexity of memory management logic makes
the code less prone to memory leaks and easier to maintain.

Signed-off-by: Shriram Shastry <[email protected]>

Author: ShriramShastry

src/audio/multiband_drc/multiband_drc.c

@@ -128,43 +128,62 @@ static int multiband_drc_init_coef(struct processing_module *mod, int16_t nch, u
 	comp_info(dev, "multiband_drc_init_coef(), initializing %i-way crossover",
 		  config->num_bands);
 
+	/* Allocate memory for all coefficient arrays in a single block */
+	/* For crossover, emphasis, and deemphasis */
+	size_t total_coefficients_size = sizeof(struct sof_eq_iir_biquad) *
+					 num_bands * nch * 3;
+
+	struct sof_eq_iir_biquad *coefficients_block =
+	    rzalloc(SOF_MEM_ZONE_RUNTIME, 0, SOF_MEM_CAPS_RAM,
+		    total_coefficients_size);
+
+	if (!coefficients_block) {
+		comp_err(dev, "multiband_drc_init_coef(), failed to allocate memory for coefficients");
+		return -ENOMEM;
+	}
+
+	/* Assign allocated memory blocks */
+	crossover = coefficients_block;
+	emphasis = coefficients_block + num_bands * nch;
+	deemphasis = emphasis + num_bands * nch;
+
 	/* Crossover: collect the coef array and assign it to every channel */
-	crossover = config->crossover_coef;
 	for (ch = 0; ch < nch; ch++) {
 		ret = crossover_init_coef_ch(crossover, &state->crossover[ch],
 					     config->num_bands);
 		/* Free all previously allocated blocks in case of an error */
 		if (ret < 0) {
 			comp_err(dev,
 				 "multiband_drc_init_coef(), could not assign coeffs to ch %d", ch);
+			rfree(coefficients_block);
 			goto err;
 		}
 	}
 
 	comp_info(dev, "multiband_drc_init_coef(), initializing emphasis_eq");
 
 	/* Emphasis: collect the coef array and assign it to every channel */
-	emphasis = config->emp_coef;
 	for (ch = 0; ch < nch; ch++) {
 		ret = multiband_drc_eq_init_coef_ch(emphasis, &state->emphasis[ch]);
 		/* Free all previously allocated blocks in case of an error */
 		if (ret < 0) {
 			comp_err(dev, "multiband_drc_init_coef(), could not assign coeffs to ch %d",
 				 ch);
+			rfree(coefficients_block);
 			goto err;
 		}
 	}
 
 	comp_info(dev, "multiband_drc_init_coef(), initializing deemphasis_eq");
 
 	/* Deemphasis: collect the coef array and assign it to every channel */
-	deemphasis = config->deemp_coef;
 	for (ch = 0; ch < nch; ch++) {
 		ret = multiband_drc_eq_init_coef_ch(deemphasis, &state->deemphasis[ch]);
 		/* Free all previously allocated blocks in case of an error */
 		if (ret < 0) {
 			comp_err(dev, "multiband_drc_init_coef(), could not assign coeffs to ch %d",
 				 ch);
+			rfree(coefficients_block);
 			goto err;
 		}
 	}
@@ -177,6 +196,7 @@ static int multiband_drc_init_coef(struct processing_module *mod, int16_t nch, u
 		if (ret < 0) {
 			comp_err(dev,
 				 "multiband_drc_init_coef(), could not init pre delay buffers");
+			rfree(coefficients_block);
 			goto err;
 		}
 
@@ -191,6 +211,10 @@ static int multiband_drc_init_coef(struct processing_module *mod, int16_t nch, u
 	return 0;
 
 err:
+	/* Free allocated memory block on error */
+	if (coefficients_block)
+		rfree(coefficients_block);
+
 	multiband_drc_reset_state(state);
 	return ret;
 }
@@ -220,7 +244,6 @@ static int multiband_drc_init(struct processing_module *mod)
 	struct module_data *md = &mod->priv;
 	struct comp_dev *dev = mod->dev;
 	struct module_config *cfg = &md->cfg;
-	struct multiband_drc_comp_data *cd;
 	size_t bs = cfg->size;
 	int ret;
 
@@ -235,9 +258,13 @@ static int multiband_drc_init(struct processing_module *mod)
 		return -EINVAL;
 	}
 
-	cd = rzalloc(SOF_MEM_ZONE_RUNTIME, 0, SOF_MEM_CAPS_RAM, sizeof(*cd));
-	if (!cd)
+	/* Memory allocation for multiband_drc_comp_data */
+	struct multiband_drc_comp_data *cd = rzalloc(SOF_MEM_ZONE_RUNTIME, 0,
+						     SOF_MEM_CAPS_RAM, sizeof(*cd));
+	if (!cd) {
+		comp_err(dev, "multiband_drc_init(), allocation for multiband_drc_comp_data failed");
 		return -ENOMEM;
+	}
 
 	md->private = cd;
 	cd->multiband_drc_func = NULL;