userspace: proxy: Add partition for k_heap struct

Add a memory partition for the module driver heap k_heap structure to the
module's memory domain to allow it to be referenced by syscalls. When a new
memory domain is created, only L2 entries mapped with OPTION_SAVE_ATTRS are
copied. Memory mapped dynamically during firmware execution is not
accessible in new memory domains by default.

Update the code to reflect the removal of memory double mapping in Zephyr
by replacing the CONFIG_XTENSA_MMU_DOUBLE_MAP with a simple
CONFIG_SOF_ZEPHYR_HEAP_CACHED check.

Signed-off-by: Adrian Warecki <adrian.warecki@intel.com>

Author: softwarecki

src/audio/module_adapter/library/userspace_proxy.c

@@ -276,8 +276,24 @@ static int userspace_proxy_memory_init(struct userspace_context *user_ctx,
 	tr_dbg(&userspace_proxy_tr, "Heap partition %#lx + %zx, attr = %u",
 	       heap_part.start, heap_part.size, heap_part.attr);
 
-#if !defined(CONFIG_XTENSA_MMU_DOUBLE_MAP) && defined(CONFIG_SOF_ZEPHYR_HEAP_CACHED)
-#define HEAP_PART_CACHED
+	/* When a new memory domain is created, only the "factory" entries from the L2 page
+	 * tables are copied. Memory that was dynamically mapped during firmware execution
+	 * will not be accessible from the new domain. The k_heap structure (drv->user_heap)
+	 * resides in such dynamically mapped memory, so we must explicitly add a partition
+	 * for it to ensure that syscalls can access this structure from the userspace domain.
+	 */
+	struct k_mem_partition heap_struct_part;
+
+	k_mem_region_align(&heap_struct_part.start, &heap_struct_part.size,
+			   POINTER_TO_UINT(drv->user_heap),
+			   sizeof(*drv->user_heap), CONFIG_MM_DRV_PAGE_SIZE);
+	heap_struct_part.attr = K_MEM_PARTITION_P_RW_U_NA |
+		user_get_partition_attr(heap_struct_part.start) | XTENSA_MMU_PERM_W;
+
+	tr_err(&userspace_proxy_tr, "Heap struct partition %#lx + %zx, attr = %u",
+	       heap_struct_part.start, heap_struct_part.size, heap_struct_part.attr);
+
+#if defined(CONFIG_SOF_ZEPHYR_HEAP_CACHED)
 	/* Add cached module private heap to memory partitions */
 	struct k_mem_partition heap_cached_part = {
 		.attr = K_MEM_PARTITION_P_RW_U_RW | XTENSA_MMU_CACHED_WB
@@ -296,10 +312,11 @@ static int userspace_proxy_memory_init(struct userspace_context *user_ctx,
 		 * These include ops structures marked with APP_TASK_DATA.
 		 */
 		&common_partition,
-#ifdef HEAP_PART_CACHED
+#ifdef CONFIG_SOF_ZEPHYR_HEAP_CACHED
 		&heap_cached_part,
 #endif
-		&heap_part
+		&heap_part,
+		&heap_struct_part
 	};
 
 	tr_dbg(&userspace_proxy_tr, "Common partition %#lx + %zx, attr = %u",

zephyr/lib/userspace_helper.c

@@ -23,8 +23,6 @@
 #include <sof/lib/dai.h>
 #include <sof/lib/dma.h>
 
-#define MODULE_DRIVER_HEAP_CACHED		CONFIG_SOF_ZEPHYR_HEAP_CACHED
-
 /* Zephyr includes */
 #include <zephyr/kernel.h>
 #include <zephyr/app_memory/app_memdomain.h>