vm: region: add a function to write data from a kernel buffer to a vm-region

include/kernel/vm-region.h

@@ -6,7 +6,7 @@
 #include <kernel/vm.h>
 
 #define VM_REGION_NAME_MAX 64
-#define VM_REGION_COPY_ALL ((size_t) - 1)
+#define VM_REGION_COPY_ALL ((size_t)-1)
 
 struct vm_region;
 struct vm_object;
@@ -157,6 +157,15 @@ extern kern_status_t vm_region_read_kernel(
 	void *dest,
 	size_t *nr_read);
 
+/* write data to the user-space area of a vm-region from a kernel-mode buffer
+ */
+extern kern_status_t vm_region_write_kernel(
+	struct vm_region *dst_region,
+	virt_addr_t dst_ptr,
+	size_t count,
+	const void *src,
+	size_t *nr_written);
+
 extern kern_status_t vm_region_memmove(
 	struct vm_region *dest_region,
 	virt_addr_t dest_ptr,