llext: avoid reloading libraries during resume

Currently when resuming from D3 we lose the complete LLEXT context,
which forces SOF to reload all the libraries, which costs time. This
isn't necessary, because the libraries are stored in DRAM, which
preserves its contents across DSP reset. Instead of reloading save
LLEXT context before power down and reload it when resuming.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

app/boards/intel_adsp_ace15_mtpm.conf

@@ -68,6 +68,7 @@ CONFIG_DEBUG_COREDUMP_MEMORY_DUMP_MIN=y
 CONFIG_HEAP_MEM_POOL_SIZE=8192
 CONFIG_LLEXT=y
 CONFIG_LLEXT_STORAGE_WRITABLE=y
+CONFIG_LLEXT_EXPERIMENTAL=y
 CONFIG_MODULES=y
 CONFIG_TIMING_FUNCTIONS=y
 CONFIG_WATCHDOG=y

app/boards/intel_adsp_ace20_lnl.conf

@@ -52,6 +52,7 @@ CONFIG_COUNTER=y
 CONFIG_HEAP_MEM_POOL_SIZE=8192
 CONFIG_LLEXT=y
 CONFIG_LLEXT_STORAGE_WRITABLE=y
+CONFIG_LLEXT_EXPERIMENTAL=y
 CONFIG_MODULES=y
 CONFIG_TIMING_FUNCTIONS=y
 

app/boards/intel_adsp_ace30_ptl.conf

@@ -53,6 +53,7 @@ CONFIG_HEAP_MEM_POOL_SIZE=8192
 CONFIG_L3_HEAP=y
 CONFIG_LLEXT=y
 CONFIG_LLEXT_STORAGE_WRITABLE=y
+CONFIG_LLEXT_EXPERIMENTAL=y
 CONFIG_MODULES=y
 
 # Zephyr / device drivers

src/include/ipc4/notification.h

@@ -114,6 +114,8 @@ enum sof_ipc4_resource_type {
 		(((SOF_IPC4_NOTIFY_FW_READY) << (SOF_IPC4_GLB_NOTIFY_TYPE_SHIFT)) |\
 		((SOF_IPC4_GLB_NOTIFICATION) << (SOF_IPC4_GLB_NOTIFY_MSG_TYPE_SHIFT)))
 
+#define SOF_IPC4_FW_READY_LIB_RESTORED		BIT(15)
+
 #define SOF_IPC4_NOTIF_HEADER(notif_type) \
 		((notif_type) << (SOF_IPC4_GLB_NOTIFY_TYPE_SHIFT) | \
 		((SOF_IPC4_GLB_NOTIFICATION) << (SOF_IPC4_GLB_NOTIFY_MSG_TYPE_SHIFT)))

src/include/sof/llext_manager.h

@@ -38,4 +38,12 @@ bool comp_is_llext(struct comp_dev *comp);
 #define comp_is_llext(comp) false
 #endif
 
+#if CONFIG_LLEXT && !CONFIG_ADSP_IMR_CONTEXT_SAVE
+int llext_manager_store_to_dram(void);
+int llext_manager_restore_from_dram(void);
+#else
+#define llext_manager_store_to_dram() 0
+#define llext_manager_restore_from_dram() -ENOSYS
+#endif
+
 #endif

src/ipc/ipc4/handler.c

@@ -23,6 +23,7 @@
 #include <sof/lib/mailbox.h>
 #include <sof/lib/memory.h>
 #include <sof/lib/pm_runtime.h>
+#include <sof/llext_manager.h>
 #include <sof/math/numbers.h>
 #include <sof/tlv.h>
 #include <sof/trace/trace.h>
@@ -1485,6 +1486,17 @@ __cold static int ipc4_module_process_dx(struct ipc4_message_request *ipc4)
 			return IPC4_BUSY;
 		}
 
+#if !CONFIG_ADSP_IMR_CONTEXT_SAVE
+		ret = llext_manager_store_to_dram();
+		if (ret < 0)
+			ipc_cmd_err(&ipc_tr, "Error %d saving LLEXT context. Resume might fail.",
+				    ret);
+
+#if CONFIG_L3_HEAP
+		l3_heap_save();
+#endif
+#endif
+
 #if defined(CONFIG_PM)
 		ipc_get()->task_mask |= IPC_TASK_POWERDOWN;
 #endif

src/library_manager/CMakeLists.txt

@@ -5,5 +5,8 @@ if(CONFIG_LIBRARY_MANAGER)
 
   if (CONFIG_MM_DRV AND CONFIG_LLEXT)
     add_local_sources(sof llext_manager.c)
+    if(NOT CONFIG_ADSP_IMR_CONTEXT_SAVE)
+      add_local_sources_ifdef(CONFIG_L3_HEAP sof llext_manager_dram.c)
+    endif()
   endif()
 endif()