math: iir: add an option to build IIR as a module

Enable building IIR support library as a LLEXT module.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

src/math/CMakeLists.txt

@@ -54,12 +54,17 @@ if(CONFIG_MATH_FFT)
   add_subdirectory(fft)
 endif()
 
-if(CONFIG_MATH_IIR_DF2T)
-  list(APPEND base_files iir_df2t_generic.c iir_df2t_hifi3.c iir_df2t.c)
-endif()
-
-if(CONFIG_MATH_IIR_DF1)
-  list(APPEND base_files iir_df1_generic.c iir_df1_hifi3.c iir_df1_hifi4.c iir_df1_hifi5.c iir_df1.c)
+if(CONFIG_MATH_IIR STREQUAL "m")
+  add_subdirectory(iir_llext ${PROJECT_BINARY_DIR}/iir_llext)
+  add_dependencies(app iir)
+elseif(CONFIG_MATH_IIR)
+  if(CONFIG_MATH_IIR_DF2T)
+    list(APPEND base_files iir_df2t_generic.c iir_df2t_hifi3.c iir_df2t.c)
+  endif()
+
+  if(CONFIG_MATH_IIR_DF1)
+    list(APPEND base_files iir_df1_generic.c iir_df1_hifi3.c iir_df1_hifi4.c iir_df1_hifi5.c iir_df1.c)
+  endif()
 endif()
 
 if(CONFIG_MATH_WINDOW)

src/math/Kconfig

@@ -178,15 +178,24 @@ config MATH_FIR
 	  filter calculates a convolution of input PCM sample and a configurable
 	  impulse response.
 
+config MATH_IIR
+	tristate "Select IIR filter library build method"
+	default m if LIBRARY_DEFAULT_MODULAR
+	default y
+	help
+	  A helper option for MATH_IIR_DF2T and MATH_IIR_DF1
+
 config MATH_IIR_DF2T
 	bool "IIR DF2T filter library"
+	depends on MATH_IIR != "n"
 	default n
 	help
 	  Select this to build IIR (Infinite Impulse Response) filter
 	  or type 2-transposed library.
 
 config MATH_IIR_DF1
 	bool "IIR DF1 filter library"
+	depends on MATH_IIR != "n"
 	default n
 	help
 	  Select this to build IIR (Infinite Impulse Response) filter

src/math/iir.toml

@@ -0,0 +1,6 @@
+	[[module.entry]]
+	name = "IIR"
+	uuid = "B0CDCD9E-EF8B-404F-8480-0F287FC9D44D"
+	load_type = "3"
+
+	index = __COUNTER__

src/math/iir_llext/CMakeLists.txt

@@ -0,0 +1,22 @@
+# Copyright (c) 2024 Intel Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+if(CONFIG_MATH_IIR_DF1)
+  set(df1 ../iir_df1.c ../iir_df1_generic.c ../iir_df1_hifi3.c
+	  ../iir_df1_hifi4.c ../iir_df1_hifi5.c)
+else()
+  set(df1 "")
+endif()
+
+if(CONFIG_MATH_IIR_DF2T)
+  set(df2t ../iir_df2t.c ../iir_df2t_generic.c ../iir_df2t_hifi3.c)
+else()
+  set(df2t "")
+endif()
+
+if(CONFIG_MATH_IIR_DF1 OR CONFIG_MATH_IIR_DF2T)
+  sof_llext_build("iir"
+		  SOURCES iir.c ${df1} ${df2t}
+		  LIB openmodules
+  )
+endif()

src/math/iir_llext/iir.c

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: BSD-3-Clause
+//
+// Copyright(c) 2025 Intel Corporation.
+
+/* modular: llext dynamic link */
+
+#include <sof/compiler_attributes.h>
+#include <sof/lib/uuid.h>
+#include <module/module/api_ver.h>
+#include <module/module/llext.h>
+#include <rimage/sof/user/manifest.h>
+
+static const struct sof_man_module_manifest mod_manifest[] __section(".module") __used = {
+	SOF_LLEXT_AUX_MANIFEST("IIR", NULL, SOF_REG_UUID(iir)),
+};
+
+SOF_LLEXT_BUILDINFO;

src/math/iir_llext/llext.toml.h

@@ -0,0 +1,5 @@
+#include <tools/rimage/config/platform.toml>
+#include "../iir.toml"
+
+[module]
+count = __COUNTER__

uuid-registry.txt

@@ -84,6 +84,7 @@ b780a0a6-269f-466f-b47723dfa05af758 google_rtc_audio_processing
 a5dacb0e-88dc-415c-a1b53e8df77f1976 idc_cmd_task
 b90f5a4e-5537-4375-a1df95485472ff9e idc_task
 696ae2bc-2877-11eb-adc10242ac120002 igo_nr
+b0cdcd9e-ef8b-404f-84800f287fc9d44d iir
 fa00558c-d653-4851-a03ab21f125a9524 interrupt
 2f520e85-49ba-4284-90d83def24af313b intc_mt8196
 be60f97d-78df-4796-a0ee435cb56b720a ipc