kconfig: heap: Add Kconfig option to set virtual memory heap size.

Allow the developer to set the maximum virtual heap size so that power
savings can be made when full memory is not required for device use cases.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

Author: lrgirdwo

zephyr/Kconfig

@@ -33,6 +33,15 @@ config SOF_ZEPHYR_HEAP_SIZE
 	 NOTE: Keep in mind that the heap size should not be greater than the physical
 	 memory size of the system defined in DT (and this includes baseFW text/data).
 
+config SOF_ZEPHYR_VIRTUAL_HEAP_SIZE
+	hex "Size of the Zephyr virtual heap for SOF"
+	depends on VIRTUAL_HEAP
+	default 0x40000
+	help
+	 Support scaling of the virtual address heap size for different platforms.
+	 NOTE: Keep in mind that the heap size should not be greater than the physical
+	 memory size of the system defined in DT (and this includes baseFW text/data).
+
 config ZEPHYR_NATIVE_DRIVERS
 	bool "Use Zephyr native drivers"
 	default n

zephyr/lib/alloc.c

@@ -18,6 +18,7 @@
 #include <sof/trace/trace.h>
 #include <rtos/symbol.h>
 #include <rtos/wait.h>
+
 #if CONFIG_VIRTUAL_HEAP
 #include <sof/lib/regions_mm.h>
 
@@ -27,7 +28,7 @@ struct vmh_heap *virtual_buffers_heap;
 #undef	HEAPMEM_SIZE
 /* Buffers are allocated from virtual space so we can safely reduce the heap size.
  */
-#define	HEAPMEM_SIZE 0x40000
+#define	HEAPMEM_SIZE CONFIG_SOF_ZEPHYR_VIRTUAL_HEAP_SIZE
 #endif /* CONFIG_VIRTUAL_HEAP */