[Userspace LL] audio: pipeline: enable position reporting for user-space pipelines

[kv2019i]

Place the pipeline position lookup table in the sysuser memory partition and replace k_spinlock with a dynamically allocated k_mutex when CONFIG_SOF_USERSPACE_LL is enabled. Spinlocks disable interrupts which is a privileged operation unavailable from user-mode threads.

The mutex pointer is stored in a separate APP_SYSUSER_BSS variable outside the SHARED_DATA struct so Zephyr's kernel object tracking can recognize it for syscall verification.

Move pipeline_posn_init() from task_main_start() to primary_core_init() before platform_init(), so the mutex is allocated before ipc_user_init() grants thread access to it.

In pipeline_posn_get(), bypass the sof_get() kernel singleton and access the shared structure directly when running in user-space. Grant the ipc_user_init thread access to the pipeline position mutex via new pipeline_posn_grant_access() helper.

[kv2019i]

For context, this is part of #10558

[Copilot]

Pull request overview

This PR updates SOF’s pipeline position reporting to work with Zephyr user-mode LL pipelines by moving the position lookup table into the sysuser memory partition and replacing an interrupt-disabling spinlock with a dynamically allocated mutex when CONFIG_SOF_USERSPACE_LL is enabled.

Changes:

• Move pipeline_posn_init() earlier in boot (primary_core_init()), before platform_init() triggers user-space IPC initialization.
• Add a pipeline_posn_grant_access() helper and grant the user IPC thread access to the dynamically allocated pipeline position mutex.
• Update pipeline position bookkeeping to use a mutex (userspace LL) vs. spinlock (non-userspace), and bypass sof_get() in user-space for direct access to shared state.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
zephyr/wrapper.c	Removes late pipeline_posn_init() call from task_main_start() after init is moved earlier.
src/ipc/ipc-common.c	Grants the user IPC thread access to the pipeline position mutex.
src/init/init.c	Initializes pipeline position offsets before platform_init() to ensure the mutex exists before user IPC setup.
src/include/sof/audio/pipeline.h	Adds a userspace-LL-only API to grant thread access to the position mutex.
src/audio/pipeline/pipeline-graph.c	Moves position table into sysuser partition, replaces spinlock usage with mutex under userspace LL, adds access-grant helper, and adjusts userspace lookup.

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[kv2019i]

Addressed in V2.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

Suppressed comments (4)

src/audio/pipeline/pipeline-graph.c:209

• CONFIG_SOF_USERSPACE_LL does not depend on CONFIG_ZEPHYR_LOG, which defaults to disabled, while the non-Zephyr logging path obtains its trace context from p->tctx. Skipping this initialization for every userspace build therefore leaves a zeroed trace context and makes subsequent pipe_*() calls invalid in a supported configuration. Either require/select Zephyr logging for userspace LL or provide a user-accessible trace-context initialization path.

#ifndef CONFIG_SOF_USERSPACE_LL
/*
* pipe_tr lives in the .trace_ctx section, which is not mapped into
* the sysuser partition, so it cannot be read from a user-mode thread.
* The copy is also unnecessary in that configuration: with Zephyr

src/audio/pipeline/pipeline-graph.c:91

• The new unlock helper lacks the required Doxygen function documentation.

static inline void pipeline_posn_unlock(struct pipeline_posn *posn, pipeline_posn_key_t key)

src/audio/pipeline/pipeline-graph.c:170

• The existing userspace pipeline test invokes pipeline_new() from a normal ZTEST, so it runs in supervisor mode and cannot detect missing mutex permissions or inaccessible sysuser memory. Add a user-mode test (for example ZTEST_USER) that creates and frees a pipeline after receiving this grant, so the central syscall-verification behavior introduced here is covered.

void pipeline_posn_grant_access(struct k_thread *thread)
{
k_thread_access_grant(thread, pipeline_posn_mutex);

src/audio/pipeline/pipeline-graph.c:84

• The new lock helper lacks the required Doxygen function documentation.

static inline pipeline_posn_key_t pipeline_posn_lock(struct pipeline_posn *posn)

[kv2019i]

V2 update:

• addressed code review comment