zephyr: userspace_helper: add user_access_to_mailbox()

Add helper function to make memory regions needed for sof/mailbox.h
available to a user thread.

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

Author: kv2019i

zephyr/include/rtos/userspace_helper.h

@@ -91,4 +91,23 @@ int user_stack_free(void *p_stack);
  */
 void module_driver_heap_remove(struct k_heap *mod_drv_heap);
 
+#ifdef CONFIG_USERSPACE
+
+/**
+ * Add access to mailbox.h interface to a user-space thread.
+ *
+ * @param domain memory domain to add the mailbox partitions to
+ * @param thread_id user-space thread for which access is added
+ */
+int user_access_to_mailbox(struct k_mem_domain *domain, k_tid_t thread_id);
+
+#else
+
+static inline int user_access_to_mailbox(struct k_mem_domain *domain, k_tid_t thread_id)
+{
+	return 0;
+}
+
+#endif /* CONFIG_USERSPACE */
+
 #endif /* __ZEPHYR_LIB_USERSPACE_HELPER_H__ */

zephyr/lib/userspace_helper.c

@@ -18,6 +18,7 @@
 #include <rtos/userspace_helper.h>
 #include <sof/audio/module_adapter/module/generic.h>
 #include <sof/audio/module_adapter/library/userspace_proxy.h>
+#include <sof/lib/mailbox.h>
 
 #define MODULE_DRIVER_HEAP_CACHED		CONFIG_SOF_ZEPHYR_HEAP_CACHED
 
@@ -82,6 +83,46 @@ int user_memory_init_shared(k_tid_t thread_id, struct processing_module *mod)
 	return k_mem_domain_add_thread(comp_dom, thread_id);
 }
 
+int user_access_to_mailbox(struct k_mem_domain *domain, k_tid_t thread_id)
+{
+	struct k_mem_partition mem_partition;
+	int ret;
+
+	/*
+	 * Start with mailbox_swregs. This is aligned with mailbox.h
+	 * implementation with uncached addressed used for register I/O.
+	 */
+	mem_partition.start =
+		(uintptr_t)sys_cache_uncached_ptr_get((void __sparse_cache *)MAILBOX_SW_REG_BASE);
+
+	BUILD_ASSERT(MAILBOX_SW_REG_SIZE == CONFIG_MMU_PAGE_SIZE);
+	mem_partition.size = CONFIG_MMU_PAGE_SIZE;
+	mem_partition.attr = K_MEM_PARTITION_P_RW_U_RW;
+
+	ret = k_mem_domain_add_partition(domain, &mem_partition);
+	if (ret < 0)
+		return ret;
+
+#ifndef CONFIG_IPC_MAJOR_4
+	/*
+	 * Next mailbox_stream (not available in IPC4). Stream access is cached,
+	 * so different mapping this time.
+	 */
+	mem_partition.start =
+		(uintptr_t)sys_cache_cached_ptr_get((void *)SRAM_STREAM_BASE);
+	BUILD_ASSERT(MAILBOX_STREAM_SIZE == CONFIG_MMU_PAGE_SIZE);
+	/* size and attr the same as for mailbox_swregs */
+
+	ret = k_mem_domain_add_partition(domain, &mem_partition);
+	if (ret < 0)
+		return ret;
+#endif
+
+	k_mem_domain_add_thread(domain, thread_id);
+
+	return 0;
+}
+
 #else /* CONFIG_USERSPACE */
 
 void *user_stack_allocate(size_t stack_size, uint32_t options)