ipc4: add user-space command-forwarding context

Add the struct ipc_user descriptor (and its ipc_user_pdata slot in struct
ipc) that the IPC4 kernel handler uses to forward commands to the
user-space IPC thread: the two IPC4 message words, the reply fields, and
a user-readable copy of the resolved comp_driver + tr_ctx used by
user-space component creation.

In ipc4 helper, allow component buffers to be allocated from the LL user
heap (ipc->ll_alloc) and create them on the component's configured core
rather than the current CPU, so buffer creation works from the user
thread when CONFIG_SOF_USERSPACE_LL is enabled.

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

Author: kv2019i

src/include/sof/ipc/common.h

@@ -22,6 +22,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+struct comp_driver;
 struct dma_sg_elem_array;
 struct ipc_msg;
 
@@ -53,6 +54,37 @@ extern struct tr_ctx ipc_tr;
 #define IPC_TASK_SECONDARY_CORE	BIT(2)
 #define IPC_TASK_POWERDOWN      BIT(3)
 
+struct ipc_user {
+	struct k_thread *thread;
+	struct k_sem *sem;
+	struct k_event *event;
+	/** @brief Copy of IPC4 message primary word forwarded to user thread */
+	uint32_t ipc_msg_pri;
+	/** @brief Copy of IPC4 message extension word forwarded to user thread */
+	uint32_t ipc_msg_ext;
+	/** @brief Result code from user thread processing */
+	int result;
+	/** @brief Reply extension word from user thread (e.g. CONFIG_GET result) */
+	uint32_t reply_ext;
+	/** @brief Reply TX data size from user thread (e.g. LARGE_CONFIG_GET result) */
+	uint32_t reply_tx_size;
+	/** @brief Reply TX data pointer from user thread (e.g. LARGE_CONFIG_GET result) */
+	void *reply_tx_data;
+	struct ipc *ipc;
+	struct k_thread *audio_thread;
+	/** @brief Original kernel driver pointer for restoring dev->drv after create */
+	const struct comp_driver *init_drv;
+	/**
+	 * @brief User-accessible copy of comp_driver + tr_ctx for create().
+	 *
+	 * The comp_driver and tr_ctx structs reside in kernel memory
+	 * (.rodata/.data) which is not user-readable. The kernel handler
+	 * copies them here before forwarding to the user thread.
+	 * Size verified by BUILD_ASSERT in handler-user.c.
+	 */
+	uint8_t init_drv_data[160] __aligned(4);
+};
+
 struct ipc {
 	struct k_spinlock lock;	/* locking mechanism */
 	void *comp_data;
@@ -75,6 +107,7 @@ struct ipc {
 #endif
 
 #ifdef CONFIG_SOF_USERSPACE_LL
+	struct ipc_user *ipc_user_pdata;
 	struct mod_alloc_ctx *ll_alloc;
 #endif
 

src/ipc/ipc4/helper.c

@@ -572,7 +572,10 @@ __cold static struct comp_buffer *ipc4_create_buffer(struct comp_dev *src, bool
 	ipc_buf.size = buf_size;
 	ipc_buf.comp.id = IPC4_COMP_ID(src_queue, dst_queue);
 	ipc_buf.comp.pipeline_id = src->ipc_config.pipeline_id;
-	ipc_buf.comp.core = cpu_get_id();
+
+	assert(IS_ENABLED(CONFIG_SOF_USERSPACE_LL) || src->ipc_config.core == cpu_get_id());
+	ipc_buf.comp.core = src->ipc_config.core;
+
 	return buffer_new(alloc, &ipc_buf, is_shared);
 }
 
@@ -715,6 +718,11 @@ __cold int ipc_comp_connect(struct ipc *ipc, ipc_pipe_comp_connect *_connect)
 #else
 	alloc = NULL;
 #endif /* CONFIG_ZEPHYR_DP_SCHEDULER */
+
+#ifdef CONFIG_SOF_USERSPACE_LL
+	if (!alloc)
+		alloc = ipc->ll_alloc;
+#endif
 	bool cross_core_bind = source->ipc_config.core != sink->ipc_config.core;
 
 	/* If both components are on same core -- process IPC on that core,