fir: enable building FIR support code as an LLEXT object

FIR support code is used by eq-fir and by tdfb. When both of them are
built as LLEXT modules, FIR supporting functions can be dynamically
loaded too.

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

Author: lyakh

src/math/Kconfig

@@ -170,7 +170,7 @@ choice "FILTER_SIMD_LEVEL_SELECT"
 endchoice
 
 config MATH_FIR
-	bool "FIR filter library"
+	tristate "FIR filter library"
 	default n
 	help
 	  This option builds FIR (Finite Impulse Response) filter library. It

src/math/fir.toml

@@ -0,0 +1,6 @@
+	[[module.entry]]
+	name = "FIR"
+	uuid = "93446E12-1864-4E04-AFE0-3B1D778FFB79"
+	load_type = "3"
+
+	index = __COUNTER__

src/math/fir_common.c

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: BSD-3-Clause
+//
+// Copyright(c) 2024 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>
+
+#include <stddef.h>
+
+static const struct sof_man_module_manifest mod_manifest __section(".module") __used =
+	SOF_LLEXT_AUX_MANIFEST("FIR", NULL, SOF_REG_UUID(fir));
+
+SOF_LLEXT_BUILDINFO;

src/math/fir_generic.c

@@ -118,6 +118,7 @@ int32_t fir_32x16(struct fir_state_32x16 *fir, int32_t x)
 	/* Q2.46 -> Q2.31, saturate to Q1.31 */
 	return sat_int32(y >> shift);
 }
+EXPORT_SYMBOL(fir_32x16);
 
 void fir_32x16_2x(struct fir_state_32x16 *fir, int32_t x0, int32_t x1, int32_t *y0, int32_t *y1)
 {
@@ -184,5 +185,6 @@ void fir_32x16_2x(struct fir_state_32x16 *fir, int32_t x0, int32_t x1, int32_t *
 	*y0 = sat_int32(a0 >> shift);
 	*y1 = sat_int32(a1 >> shift);
 }
+EXPORT_SYMBOL(fir_32x16_2x);
 
 #endif

src/math/fir_hifi2ep.c

@@ -156,6 +156,7 @@ void fir_32x16_hifiep(struct fir_state_32x16 *fir, int32_t x, int32_t *y, int ls
 	a = AE_SRAAQ56(AE_SLLASQ56S(a, lshift), rshift);
 	AE_SQ32F_I(AE_ROUNDSQ32SYM(a), (ae_q32s *)y, 0);
 }
+EXPORT_SYMBOL(fir_32x16_hifiep);
 
 /* HiFi EP has the follow number of reqisters that should not be exceeded
  * 4x 56 bit registers in register file Q
@@ -249,5 +250,6 @@ void fir_32x16_2x_hifiep(struct fir_state_32x16 *fir, int32_t x0, int32_t x1,
 	AE_SQ32F_I(AE_ROUNDSQ32SYM(b), (ae_q32s *)y1, 0);
 	AE_SQ32F_I(AE_ROUNDSQ32SYM(a), (ae_q32s *)y0, 0);
 }
+EXPORT_SYMBOL(fir_32x16_2x_hifiep);
 
 #endif

src/math/fir_hifi3.c

@@ -162,6 +162,7 @@ void fir_32x16_hifi3(struct fir_state_32x16 *fir, ae_int32 x, ae_int32 *y,
 	a = AE_SLAA64S(a, shift);
 	AE_S32_L_I(AE_ROUND32F48SSYM(a), (ae_int32 *)y, 0);
 }
+EXPORT_SYMBOL(fir_32x16_hifi3);
 
 /* HiFi EP has the follow number of reqisters that should not be exceeded
  * 4x 56 bit registers in register file Q

src/math/fir_llext/CMakeLists.txt

@@ -0,0 +1,10 @@
+# Copyright (c) 2024 Intel Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+sof_llext_build("fir"
+	SOURCES ../fir_common.c
+		../fir_generic.c
+		../fir_hifi2ep.c
+		../fir_hifi3.c
+	LIB openmodules
+)

src/math/fir_llext/llext.toml.h

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

uuid-registry.txt

@@ -72,6 +72,7 @@ f6d15ad3-b122-458c-ae9b0ab0b5867aa0 dummy_dma
 5150c0e6-27f9-4ec8-8351c705b642d12f eq_iir
 889f6dcd-ddcd-4e05-aa5b0d39f8bca961 esai
 bfc7488c-75aa-4ce8-9dbed8da08a698c2 file
+93446e12-1864-4e04-afe03b1d778ffb79 fir
 61bca9a8-18d0-4a18-8e7b2639219804b7 gain
 c3c74249-058e-414f-82404da5f3fc2389 google_hotword
 bf0e1bbc-dc6a-45fe-bc902554cb137ab4 google_ctc_audio_processing

zephyr/CMakeLists.txt

@@ -685,11 +685,17 @@ elseif(CONFIG_COMP_IIR)
 	)
 endif()
 
-zephyr_library_sources_ifdef(CONFIG_MATH_FIR
-	${SOF_MATH_PATH}/fir_generic.c
-	${SOF_MATH_PATH}/fir_hifi2ep.c
-	${SOF_MATH_PATH}/fir_hifi3.c
-)
+if(CONFIG_MATH_FIR STREQUAL "m")
+	add_subdirectory(${SOF_MATH_PATH}/fir_llext
+			 ${PROJECT_BINARY_DIR}/fir_llext)
+	add_dependencies(app fir)
+elseif(CONFIG_MATH_FIR)
+	zephyr_library_sources(
+		${SOF_MATH_PATH}/fir_generic.c
+		${SOF_MATH_PATH}/fir_hifi2ep.c
+		${SOF_MATH_PATH}/fir_hifi3.c
+	)
+endif()
 
 zephyr_library_sources_ifdef(CONFIG_MATH_IIR_DF1
 	${SOF_MATH_PATH}/iir_df1_generic.c