ipc: make ipc_msg_reply and compound-message handlers syscalls

The IPC reply and compound-message completion entry points need to be
callable from the IPC user-space thread. Declare ipc_msg_reply(),
ipc_compound_pre_start(), ipc_compound_post_start() and
ipc_wait_for_compound_msg() as Zephyr syscalls when
CONFIG_SOF_USERSPACE_LL is enabled, renaming the implementations to
z_impl_* and adding z_vrfy_* verification wrappers. A new ipc_reply.h
carries the ipc_msg_reply declaration so it can be pulled in as a
syscall header.

Register the new syscall headers in CMakeLists.txt. No functional change
for non-userspace builds, where the functions keep direct external
linkage via z_impl_* defines.

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Author: kv2019i

src/include/ipc4/handler.h

@@ -62,30 +62,43 @@ int ipc4_user_process_glb_message(struct ipc4_message_request *ipc4, struct ipc_
 int ipc4_set_pipeline_state(struct ipc4_message_request *ipc4);
 
 /**
- * \brief Increment the IPC compound message pre-start counter.
+ * \brief Complete the IPC compound message.
  * @param[in] msg_id IPC message ID.
+ * @param[in] error Error code of the IPC command.
  */
-void ipc_compound_pre_start(int msg_id);
+void ipc_compound_msg_done(uint32_t msg_id, int error);
 
+#if defined(__ZEPHYR__) && defined(CONFIG_SOF_USERSPACE_LL)
 /**
- * \brief Decrement the IPC compound message pre-start counter on return value status.
+ * \brief Increment the IPC compound message pre-start counter.
  * @param[in] msg_id IPC message ID.
- * @param[in] ret Return value of the IPC command.
- * @param[in] delayed True if the reply is delayed.
  */
-void ipc_compound_post_start(uint32_t msg_id, int ret, bool delayed);
+__syscall void ipc_compound_pre_start(int msg_id);
 
 /**
- * \brief Complete the IPC compound message.
+ * \brief Decrement the IPC compound message pre-start counter on return value status.
  * @param[in] msg_id IPC message ID.
- * @param[in] error Error code of the IPC command.
+ * @param[in] ret Return value of the IPC command.
+ * @param[in] delayed True if the reply is delayed.
  */
-void ipc_compound_msg_done(uint32_t msg_id, int error);
+__syscall void ipc_compound_post_start(uint32_t msg_id, int ret, bool delayed);
 
 /**
  * \brief Wait for the IPC compound message to complete.
  * @return 0 on success, error code otherwise on timeout.
  */
-int ipc_wait_for_compound_msg(void);
+__syscall int ipc_wait_for_compound_msg(void);
+#else
+void z_impl_ipc_compound_pre_start(int msg_id);
+#define ipc_compound_pre_start z_impl_ipc_compound_pre_start
+void z_impl_ipc_compound_post_start(uint32_t msg_id, int ret, bool delayed);
+#define ipc_compound_post_start z_impl_ipc_compound_post_start
+int z_impl_ipc_wait_for_compound_msg(void);
+#define ipc_wait_for_compound_msg z_impl_ipc_wait_for_compound_msg
+#endif
+
+#if defined(__ZEPHYR__) && defined(CONFIG_SOF_USERSPACE_LL)
+#include <zephyr/syscalls/handler.h>
+#endif
 
 #endif /* __SOF_IPC4_HANDLER_H__ */

src/include/sof/ipc/common.h

@@ -25,6 +25,7 @@
 struct comp_driver;
 struct dma_sg_elem_array;
 struct ipc_msg;
+struct ipc4_message_request;
 
 /* validates internal non tail structures within IPC command structure */
 #define IPC_IS_SIZE_INVALID(object)					\
@@ -211,6 +212,56 @@ struct dai_data;
  */
 int ipc_dai_data_config(struct dai_data *dd, struct comp_dev *dev);
 
+/**
+ * \brief Processes IPC4 userspace module message.
+ * @param[in] ipc4 IPC4 message request.
+ * @param[in] reply IPC message reply structure.
+ * @return IPC4_SUCCESS on success, error code otherwise.
+ */
+int ipc4_user_process_module_message(struct ipc4_message_request *ipc4, struct ipc_msg *reply);
+
+/**
+ * \brief Processes IPC4 userspace global message.
+ * @param[in] ipc4 IPC4 message request.
+ * @param[in] reply IPC message reply structure.
+ * @return IPC4_SUCCESS on success, error code otherwise.
+ */
+int ipc4_user_process_glb_message(struct ipc4_message_request *ipc4, struct ipc_msg *reply);
+
+/*
+ * When CONFIG_SOF_USERSPACE_LL is enabled, compound message functions are
+ * declared as syscalls in ipc4/handler.h — do not re-declare here with
+ * external linkage as that conflicts with the static inline syscall wrappers.
+ */
+#if !(defined(__ZEPHYR__) && defined(CONFIG_SOF_USERSPACE_LL))
+/**
+ * \brief Increment the IPC compound message pre-start counter.
+ * @param[in] msg_id IPC message ID.
+ */
+void ipc_compound_pre_start(int msg_id);
+
+/**
+ * \brief Decrement the IPC compound message pre-start counter on return value status.
+ * @param[in] msg_id IPC message ID.
+ * @param[in] ret Return value of the IPC command.
+ * @param[in] delayed True if the reply is delayed.
+ */
+void ipc_compound_post_start(uint32_t msg_id, int ret, bool delayed);
+
+/**
+ * \brief Wait for the IPC compound message to complete.
+ * @return 0 on success, error code otherwise on timeout.
+ */
+int ipc_wait_for_compound_msg(void);
+#endif /* !CONFIG_SOF_USERSPACE_LL */
+
+/**
+ * \brief Complete the IPC compound message.
+ * @param[in] msg_id IPC message ID.
+ * @param[in] error Error code of the IPC command.
+ */
+void ipc_compound_msg_done(uint32_t msg_id, int error);
+
 /**
  * \brief create a IPC boot complete message.
  * @param[in] header header.
@@ -285,7 +336,7 @@ int ipc_process_on_core(uint32_t core, bool blocking);
  * \brief reply to an IPC message.
  * @param[in] reply pointer to the reply structure.
  */
-void ipc_msg_reply(struct sof_ipc_reply *reply);
+#include <sof/ipc/ipc_reply.h>
 
 /**
  * \brief Call platform-specific IPC completion function.

src/include/sof/ipc/ipc_reply.h

@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright(c) 2026 Intel Corporation. All rights reserved.
+ */
+
+#ifndef __SOF_IPC_IPC_REPLY_H__
+#define __SOF_IPC_IPC_REPLY_H__
+
+#include <ipc/header.h>
+
+struct sof_ipc_reply;
+
+/**
+ * \brief reply to an IPC message.
+ * @param[in] reply pointer to the reply structure.
+ */
+#if defined(__ZEPHYR__) && defined(CONFIG_SOF_USERSPACE_LL)
+__syscall void ipc_msg_reply(struct sof_ipc_reply *reply);
+#else
+void z_impl_ipc_msg_reply(struct sof_ipc_reply *reply);
+#define ipc_msg_reply z_impl_ipc_msg_reply
+#endif
+
+#if defined(__ZEPHYR__) && defined(CONFIG_SOF_USERSPACE_LL)
+#include <zephyr/syscalls/ipc_reply.h>
+#endif
+
+#endif /* __SOF_IPC_IPC_REPLY_H__ */

src/ipc/ipc3/helper.c

@@ -727,7 +727,7 @@ int ipc_comp_new(struct ipc *ipc, ipc_comp *_comp)
 	return 0;
 }
 
-void ipc_msg_reply(struct sof_ipc_reply *reply)
+void z_impl_ipc_msg_reply(struct sof_ipc_reply *reply)
 {
 	struct ipc *ipc = ipc_get();
 	k_spinlock_key_t key;

src/ipc/ipc4/handler-kernel.c

@@ -40,6 +40,11 @@
 #include <rtos/string.h>
 #include <sof/lib_manager.h>
 
+#ifdef __ZEPHYR__
+#include <zephyr/kernel.h>
+#include <zephyr/internal/syscall_handler.h>
+#endif
+
 #include <errno.h>
 #include <stdbool.h>
 #include <stddef.h>
@@ -128,15 +133,31 @@ __cold static bool is_any_ppl_active(void)
 	return false;
 }
 
-void ipc_compound_pre_start(int msg_id)
+void z_impl_ipc_compound_pre_start(int msg_id)
 {
 	/* ipc thread will wait for all scheduled tasks to be complete
 	 * Use a reference count to check status of these tasks.
 	 */
 	atomic_add(&msg_data.delayed_reply, 1);
 }
 
-void ipc_compound_post_start(uint32_t msg_id, int ret, bool delayed)
+#ifdef CONFIG_USERSPACE
+/**
+ * \brief Userspace verification wrapper for ipc_compound_pre_start().
+ *
+ * Forwards the call to z_impl_ipc_compound_pre_start(). No pointer
+ * validation is needed as only primitive types are passed.
+ *
+ * @param[in] msg_id IPC message ID.
+ */
+void z_vrfy_ipc_compound_pre_start(int msg_id)
+{
+	z_impl_ipc_compound_pre_start(msg_id);
+}
+#include <zephyr/syscalls/ipc_compound_pre_start_mrsh.c>
+#endif
+
+void z_impl_ipc_compound_post_start(uint32_t msg_id, int ret, bool delayed)
 {
 	if (ret) {
 		ipc_cmd_err(&ipc_tr, "failed to process msg %d status %d", msg_id, ret);
@@ -149,6 +170,24 @@ void ipc_compound_post_start(uint32_t msg_id, int ret, bool delayed)
 		atomic_sub(&msg_data.delayed_reply, 1);
 }
 
+#ifdef CONFIG_USERSPACE
+/**
+ * \brief Userspace verification wrapper for ipc_compound_post_start().
+ *
+ * Forwards the call to z_impl_ipc_compound_post_start(). No pointer
+ * validation is needed as only primitive types are passed.
+ *
+ * @param[in] msg_id IPC message ID.
+ * @param[in] ret Return value of the IPC command.
+ * @param[in] delayed True if the reply is delayed.
+ */
+void z_vrfy_ipc_compound_post_start(uint32_t msg_id, int ret, bool delayed)
+{
+	z_impl_ipc_compound_post_start(msg_id, ret, delayed);
+}
+#include <zephyr/syscalls/ipc_compound_post_start_mrsh.c>
+#endif
+
 void ipc_compound_msg_done(uint32_t msg_id, int error)
 {
 	if (!atomic_read(&msg_data.delayed_reply)) {
@@ -170,13 +209,13 @@ void ipc_compound_msg_done(uint32_t msg_id, int error)
  * be always IPC4_FAILURE. Therefore the compound messages handling is simplified. The pipeline
  * triggers will require an explicit scheduler call to get the components to desired state.
  */
-int ipc_wait_for_compound_msg(void)
+int z_impl_ipc_wait_for_compound_msg(void)
 {
 	atomic_set(&msg_data.delayed_reply, 0);
 	return IPC4_SUCCESS;
 }
 #else
-int ipc_wait_for_compound_msg(void)
+int z_impl_ipc_wait_for_compound_msg(void)
 {
 	int try_count = 30;
 
@@ -192,6 +231,22 @@ int ipc_wait_for_compound_msg(void)
 
 	return IPC4_SUCCESS;
 }
+
+#ifdef CONFIG_USERSPACE
+/**
+ * \brief Userspace verification wrapper for ipc_wait_for_compound_msg().
+ *
+ * Forwards the call to z_impl_ipc_wait_for_compound_msg(). No pointer
+ * validation is needed as no pointers are passed.
+ *
+ * @return IPC4_SUCCESS on success, IPC4_FAILURE on timeout.
+ */
+int z_vrfy_ipc_wait_for_compound_msg(void)
+{
+	return z_impl_ipc_wait_for_compound_msg();
+}
+#include <zephyr/syscalls/ipc_wait_for_compound_msg_mrsh.c>
+#endif
 #endif
 
 #if CONFIG_LIBRARY_MANAGER
@@ -509,14 +564,23 @@ void ipc_send_buffer_status_notify(void)
 }
 #endif
 
-void ipc_msg_reply(struct sof_ipc_reply *reply)
+void z_impl_ipc_msg_reply(struct sof_ipc_reply *reply)
 {
 	struct ipc4_message_request in;
 
 	in.primary.dat = msg_data.msg_in.pri;
 	ipc_compound_msg_done(in.primary.r.type, reply->error);
 }
 
+#ifdef CONFIG_USERSPACE
+void z_vrfy_ipc_msg_reply(struct sof_ipc_reply *reply)
+{
+	K_OOPS(K_SYSCALL_MEMORY_READ(reply, sizeof(*reply)));
+	z_impl_ipc_msg_reply(reply);
+}
+#include <zephyr/syscalls/ipc_msg_reply_mrsh.c>
+#endif
+
 void ipc_cmd(struct ipc_cmd_hdr *_hdr)
 {
 	struct ipc4_message_request *in = ipc4_get_message_request();

zephyr/CMakeLists.txt

@@ -622,6 +622,8 @@ zephyr_library_sources_ifdef(CONFIG_SHELL
 
 zephyr_syscall_header(${SOF_SRC_PATH}/include/sof/audio/module_adapter/module/generic.h)
 zephyr_syscall_header(${SOF_SRC_PATH}/include/sof/lib/fast-get.h)
+zephyr_syscall_header(${SOF_SRC_PATH}/include/sof/ipc/ipc_reply.h)
+zephyr_syscall_header(${SOF_SRC_PATH}/include/ipc4/handler.h)
 zephyr_syscall_header(include/rtos/alloc.h)
 zephyr_library_sources_ifdef(CONFIG_SOF_USERSPACE_INTERFACE_ALLOC syscall/alloc.c)
 zephyr_syscall_header(${SOF_SRC_PATH}/include/sof/lib/dai-zephyr.h)