zephyr: map IPC4 HOSTBOX partitions into user LL memory domain

The user-space IPC thread reads the IPC4 module init parameter block
directly from MAILBOX_HOSTBOX_BASE (comp_new_ipc4() / comp_new_ipc4_user()),
so the HOSTBOX region must be reachable from the user LL memory domain.

Map two partitions when CONFIG_SOF_USERSPACE_LL && CONFIG_IPC_MAJOR_4:
an uncached read-only view for the parameter reads, and a cached RW view
because the sys_cache_data_invd_range() syscall verifier requires write
access to the invalidated range.

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

Author: kv2019i

zephyr/lib/userspace_helper.c

@@ -110,6 +110,39 @@ int user_access_to_mailbox(struct k_mem_domain *domain, k_tid_t thread_id)
 	if (ret < 0)
 		return ret;
 
+#if defined(CONFIG_SOF_USERSPACE_LL) && defined(CONFIG_IPC_MAJOR_4)
+	/* HOSTBOX partitions for IPC4 module init parameter block reads.
+	 * comp_new_ipc4() accesses MAILBOX_HOSTBOX_BASE directly to get
+	 * the module configuration data sent by the host.
+	 */
+	struct k_mem_partition hostbox_partition;
+
+	/* Uncached HOSTBOX partition */
+	hostbox_partition.start =
+		(uintptr_t)sys_cache_uncached_ptr_get((void __sparse_cache *)MAILBOX_HOSTBOX_BASE);
+	hostbox_partition.size = ALIGN_UP(MAILBOX_HOSTBOX_SIZE,
+					  CONFIG_MMU_PAGE_SIZE);
+	hostbox_partition.attr = K_MEM_PARTITION_P_RO_U_RO;
+
+	ret = k_mem_domain_add_partition(domain, &hostbox_partition);
+	if (ret < 0)
+		return ret;
+
+	/* Cached HOSTBOX partition for cache invalidation path.
+	 * sys_cache_data_invd_range() syscall verification requires
+	 * write access to the region, so use RW instead of RO.
+	 */
+	hostbox_partition.start =
+		(uintptr_t)sys_cache_cached_ptr_get((void *)MAILBOX_HOSTBOX_BASE);
+	hostbox_partition.size = ALIGN_UP(MAILBOX_HOSTBOX_SIZE,
+					  CONFIG_MMU_PAGE_SIZE);
+	hostbox_partition.attr = K_MEM_PARTITION_P_RW_U_RW;
+
+	ret = k_mem_domain_add_partition(domain, &hostbox_partition);
+	if (ret < 0)
+		return ret;
+#endif /* CONFIG_IPC_MAJOR_4 */
+
 #ifndef CONFIG_IPC_MAJOR_4
 	/*
 	 * Next mailbox_stream (not available in IPC4). Stream access is cached,