audio: dai-zephyr: enable user-space use of DAI by kv2019i · Pull Request #10801 · thesofproject/sof

kv2019i · 2026-05-21T18:22:29Z

A series of of patches to enable dai-zephyr component to be used in user-space. This includes:

addition of new sof_umutex.h rtos interface that is used to implement DAI property locking (instead of spinlocks)
fixes to sof_dma.h (ability to use SG lists with loops)
make dai_get() work in user-space
fix use of dai_get_properties() to be safe to be used from user-space
modify heap allocations in dai-zephyr so that they will work also when building for user-space LL

Similar changes to host-zephyr are in #10799

Allow a non-null pointer at the end of the DMA transfer block list, if and only if it points to the first entry in the block list. The SOF DAI module sets the DMA transfers blocks like this and this change is required to use DAI module from user-space. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

The dai_get()/dai_put() provide a helper to access DAI devices. When used in user-space, the wrapper struct should be created in user-space memory. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Modify code to allocate DAI properties object on stack and use dai_get_properties_copy(). This is required when DAI code is run in user-space and a syscall is needed to talk to the DAI driver. It's not possible to return a pointer to kernel memory, so instead data needs to be copied to caller stack. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

The Zephyr locking interfaces do not have a variant that allows the lock object to be put in dynamically allocated user-space memory. Implement a variant on top of Zephyr k_mutex that provides this support for SOF. Provide a no-op wrapper for POSIX library builds (just like we do for other locking interfaces). Kconfig option SOF_USERSPACE_INTERFACE_MUTEX is added to control whether umutex.h is exposed to user-space or not. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

The spinlock used to protect access to DAI properties can be converted to a sof_umutex as this is only accessed from IPC and LL threads and both are normal Zephyr threads. As an additional benefit, use of sof_umutex allows to run the dai-zephyr module in user-space. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Reorder redefinitions to ensure "struct mod_alloc_ctx" is defined before lib/dai.h is included. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Convert all memory allocations to use the sof_heap_alloc() interface and pass the dai_data specific heap object. This makes dai-zephyr code compatible with use from user-space, but does not affect kernel space use. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

kv2019i · 2026-05-21T18:23:13Z

For context, part of #10558

kv2019i · 2026-05-21T18:27:34Z

+	depends on USERSPACE
+	help
+	  Allow user-space threads to use sof_heap_alloc/sof_heap_free
+	  as Zephyr system calls.


Oops, this ALLOC is a stray commit, will remove in V2.

kv2019i · 2026-05-21T18:28:23Z

  )
+  if(CONFIG_USERSPACE AND CONFIG_SOF_USERSPACE_INTERFACE_ALLOC)
+    zephyr_library_sources(userspace/test_heap_alloc.c)
+  endif()


And another stray bit for test_heap_alloc.c. Will remove in V2.

Copilot

Pull request overview

This PR enables the dai-zephyr component (and related infrastructure) to be usable from Zephyr user-space threads by introducing a user-space mutex abstraction, updating syscall verification, and adjusting allocations to work with user-space heaps/memory domains.

Changes:

Add sof_umutex API (Zephyr + POSIX) with syscall plumbing and a user-space test.
Update dai-zephyr to use sof_umutex for property protection and to use heap-aware allocation/free paths.
Update the SOF DMA syscall deep-copy logic to support cyclic (looping) SG block lists.

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
zephyr/test/userspace/test_umutex.c	Adds a user-space thread test for `sof_umutex` init/lock/unlock/free.
zephyr/test/CMakeLists.txt	Wires new user-space tests into the Zephyr test build.
zephyr/syscall/umutex.c	Adds syscall verification handlers for `sof_umutex_*`.
zephyr/syscall/sof_dma.c	Extends DMA block list deep-copy to allow looping SG lists.
zephyr/lib/umutex.c	Implements kernel-side `sof_umutex` using dynamically allocated `k_mutex`.
zephyr/Kconfig	Introduces Kconfig switches for userspace alloc + mutex interfaces and selects mutex for userspace LL.
zephyr/include/rtos/umutex.h	Declares the `sof_umutex` API and syscall wrappers.
zephyr/include/rtos/mutex.h	Exposes `sof_umutex` via the RTOS mutex umbrella header.
zephyr/CMakeLists.txt	Adds `umutex` implementation and syscall sources/headers to the Zephyr build.
src/lib/dai.c	Updates `dai_get()`/`dai_put()` allocation/free to use `sof_heap_alloc/free` (userspace LL aware).
src/ipc/ipc4/dai.c	Uses heap-aware allocation/free for `dd->dai_spec_config`.
src/include/sof/lib/dai-zephyr.h	Switches DAI property lock to `sof_umutex` and adds `mod_alloc_ctx` to `dai_data`.
src/include/sof/audio/component.h	Moves `mod_alloc_ctx` definition earlier to satisfy DAI header needs.
src/audio/dai-zephyr.c	Replaces spinlock-based property protection with `sof_umutex` and updates multiple allocations to use `alloc_ctx.heap`.
posix/include/rtos/umutex.h	Adds POSIX header wrapper for `sof_umutex`.
posix/include/rtos/mutex.h	Adds a POSIX stub implementation of `sof_umutex`.

+  if(CONFIG_USERSPACE AND CONFIG_SOF_USERSPACE_INTERFACE_ALLOC)
+    zephyr_library_sources(userspace/test_heap_alloc.c)
+  endif()


kv2019i · 2026-05-21T18:44:51Z

+static inline int z_vrfy_sof_umutex_lock(struct sof_umutex *umutex,
+					    k_timeout_t timeout)
+{
+	K_OOPS(K_SYSCALL_MEMORY_WRITE(umutex, sizeof(struct sof_umutex)));
+	return z_impl_sof_umutex_lock(umutex, timeout);
+}
+#include <zephyr/syscalls/sof_umutex_lock_mrsh.c>
+
+static inline int z_vrfy_sof_umutex_unlock(struct sof_umutex *umutex)
+{
+	K_OOPS(K_SYSCALL_MEMORY_WRITE(umutex, sizeof(struct sof_umutex)));
+	return z_impl_sof_umutex_unlock(umutex);
+}
+#include <zephyr/syscalls/sof_umutex_unlock_mrsh.c>
+
+static inline void z_vrfy_sof_umutex_free(struct sof_umutex *umutex)
+{
+	K_OOPS(K_SYSCALL_MEMORY_WRITE(umutex, sizeof(struct sof_umutex)));
+	z_impl_sof_umutex_free(umutex);


This is a valid concern. The verification is similar to zephyr sys_mutex() but it has additional step to look up the k_object() that is not here. Let me mark as draft to ensure this is addressed before merge.

+	K_OOPS(K_SYSCALL_MEMORY_WRITE(umutex, sizeof(struct sof_umutex)));
+	return z_impl_sof_umutex_lock(umutex, timeout);
+}
+#include <zephyr/syscalls/sof_umutex_lock_mrsh.c>
+
+static inline int z_vrfy_sof_umutex_unlock(struct sof_umutex *umutex)
+{
+	K_OOPS(K_SYSCALL_MEMORY_WRITE(umutex, sizeof(struct sof_umutex)));


+int z_impl_sof_umutex_init(struct sof_umutex *umutex)
+{
+	struct k_mutex *m;
+	int ret;
+
+	m = k_object_alloc(K_OBJ_MUTEX);
+	if (m == NULL) {
+		return -ENOMEM;
+	}
+
+	ret = k_mutex_init(m);
+	if (ret) {
+		k_object_free(m);
+		return ret;
+	}
+
+	umutex->mutex = m;
+	return 0;


 /* called from ipc/ipc3/dai.c */
 int dai_get_handshake(struct dai *dai, int direction, int stream_id)
 {
-	k_spinlock_key_t key = k_spin_lock(&dai->lock);
-	const struct dai_properties *props = dai_get_properties(dai->dev, direction,
-								stream_id);
-	int hs_id = props->dma_hs_id;
+	struct dai_properties props;
+	int ret;

-	k_spin_unlock(&dai->lock, key);
+	sof_umutex_lock(&dai->lock, K_FOREVER);
+	ret = dai_get_properties_copy(dai->dev, direction, stream_id, &props);
+	sof_umutex_unlock(&dai->lock);
+	if (ret < 0)


 		dd->dma_buffer = NULL;
-		dma_sg_free(NULL, &config->elem_array);
-		rfree(dd->z_config);
+		dma_sg_free(dd->alloc_ctx.heap, &config->elem_array);


kv2019i added 7 commits May 21, 2026 21:14

lib: dai: make dai_get() and dai_put() compatible with user-space

ff0bc0c

The dai_get()/dai_put() provide a helper to access DAI devices. When used in user-space, the wrapper struct should be created in user-space memory. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

audio: component: reorder include order for lib/dai.h

9545fd3

Reorder redefinitions to ensure "struct mod_alloc_ctx" is defined before lib/dai.h is included. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Copilot AI review requested due to automatic review settings May 21, 2026 18:22

kv2019i requested review from abonislawski, dbaluta, iuliana-prodan, lbetlej, lgirdwood, lyakh, mmaka1 and plbossart as code owners May 21, 2026 18:22

kv2019i requested a review from jsarha May 21, 2026 18:22

Copilot started reviewing on behalf of kv2019i May 21, 2026 18:26 View session

kv2019i commented May 21, 2026

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Copilot AI reviewed May 21, 2026

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kv2019i marked this pull request as draft May 21, 2026 18:44

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audio: dai-zephyr: enable user-space use of DAI #10801

audio: dai-zephyr: enable user-space use of DAI #10801
kv2019i wants to merge 7 commits into
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