audio: steamaudio: add Steam Audio spatial audio offload module and LLEXT

Add Valve Steam Audio spatial audio processing engine offload module
for Sound Open Firmware (SOF), supporting both statically linked DSP
processing and dynamically loaded ELF extensions (LLEXT).

Key features:
- Core 3D spatialization: direct HRTF convolution, distance attenuation,
  air absorption filtering, directivity simulation, and occlusion damping.
- Acoustic simulation: ray-traced BVH reflection rendering directly
  executed on the DSP.
- Continuous multi-channel streaming: host feeds a continuous 64-channel
  PCM stream while the DSP dynamically culls inactive sources using an
  active voice bitmask (active_sources_mask).
- Hardware-timestamped VBR metadata: receives variable bitrate spatial
  metadata packets via DMA-driven compressed ALSA PCM device (snd_compr).
- Dynamic LLEXT support: builds as steamaudio.llext for Intel ACE 3.0
  (Panther Lake) enabled via CONFIG_COMP_STEAMAUDIO=m.
- Registered component UUID 53746561-6d61-7564-696f737465616d31 in
  uuid-registry.txt and module manifest in tools/rimage/config/ptl.toml.h.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

Author: lrgirdwo

app/boards/intel_adsp_ace30_ptl.conf

@@ -15,6 +15,7 @@ CONFIG_FORMAT_CONVERT_HIFI3=n
 CONFIG_COMP_GOOGLE_RTC_AUDIO_PROCESSING=m
 CONFIG_GOOGLE_RTC_AUDIO_PROCESSING_MOCK=y
 CONFIG_COMP_STFT_PROCESS=y
+CONFIG_COMP_STEAMAUDIO=m
 
 # SOF / infrastructure
 CONFIG_KCPS_DYNAMIC_CLOCK_CONTROL=n

src/audio/CMakeLists.txt

@@ -89,6 +89,9 @@ if(NOT CONFIG_COMP_MODULE_SHARED_LIBRARY_BUILD)
 	if(CONFIG_COMP_SRC)
 		add_subdirectory(src)
 	endif()
+	if(CONFIG_COMP_STEAMAUDIO)
+		add_subdirectory(steamaudio)
+	endif()
 	if(CONFIG_COMP_STFT_PROCESS)
 		add_subdirectory(stft_process)
 	endif()

src/audio/Kconfig

@@ -154,6 +154,7 @@ rsource "selector/Kconfig"
 rsource "smart_amp/Kconfig"
 rsource "sound_dose/Kconfig"
 rsource "src/Kconfig"
+rsource "steamaudio/Kconfig"
 rsource "stft_process/Kconfig"
 rsource "tdfb/Kconfig"
 rsource "template/Kconfig"

src/audio/steamaudio/CMakeLists.txt

@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: BSD-3-Clause
+
+if(CONFIG_COMP_STEAMAUDIO STREQUAL "m" AND DEFINED CONFIG_LLEXT)
+  add_subdirectory(llext ${PROJECT_BINARY_DIR}/steamaudio_llext)
+  add_dependencies(app steamaudio)
+else()
+  add_local_sources(sof steamaudio.c)
+  add_local_sources(sof steamaudio-generic.c)
+  add_local_sources(sof steamaudio_bvh.c)
+
+  if(CONFIG_IPC_MAJOR_4)
+    add_local_sources(sof steamaudio-ipc4.c)
+  endif()
+endif()

src/audio/steamaudio/Kconfig

@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: BSD-3-Clause
+
+config COMP_STEAMAUDIO
+	tristate "Steam Audio spatial offload component"
+	default y
+	help
+	  Select for Steam Audio spatial audio offload component.
+	  Provides 3D binaural HRTF spatialization, direct sound modeling,
+	  3-band biquad IIR filtering, 8-channel Householder Feedback Delay
+	  Network (FDN) reverberation, 1st-order Ambisonics rotation/decoding,
+	  and on-chip DSP BVH ray tracing for real-time room acoustic simulation.

src/audio/steamaudio/llext/CMakeLists.txt

@@ -0,0 +1,10 @@
+# Copyright (c) 2026 Intel Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+sof_llext_build("steamaudio"
+	SOURCES	../steamaudio.c
+		../steamaudio-generic.c
+		../steamaudio_bvh.c
+		../steamaudio-ipc4.c
+	LIB openmodules
+)

src/audio/steamaudio/llext/llext.toml.h

@@ -0,0 +1,6 @@
+#include <tools/rimage/config/platform.toml>
+#define LOAD_TYPE "2"
+#include "../steamaudio.toml"
+
+[module]
+count = __COUNTER__