From 0c53a5ca35ff2c9fe68b90ff38fde6a1def62850 Mon Sep 17 00:00:00 2001
From: NAKAMURA Gou <go.nakamura.yw@hitachi-solutions.com>
Date: Mon, 28 Mar 2016 14:31:02 +0900
Subject: [PATCH] add NOPHYS which means no physical memory

---
 kernel/include/process.h | 2 ++
 kernel/process.c         | 9 ++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/kernel/include/process.h b/kernel/include/process.h
index 06a43b1c..28e9dc58 100644
--- a/kernel/include/process.h
+++ b/kernel/include/process.h
@@ -162,6 +162,8 @@
 #define USER_STACK_NR_PAGES 8192
 #define KERNEL_STACK_NR_PAGES 25
 
+#define NOPHYS ((uintptr_t)-1)
+
 #include <waitq.h>
 #include <futex.h>
 
diff --git a/kernel/process.c b/kernel/process.c
index 3a573c7c..1bd6fa3f 100644
--- a/kernel/process.c
+++ b/kernel/process.c
@@ -1023,7 +1023,14 @@ int add_process_memory_range(struct process_vm *vm,
 				range->flag);
     }
 
-	if (flag & VR_REMOTE) {
+    rc = 0;
+    if (0) {
+	    /* dummy */
+    }
+    else if (phys == NOPHYS) {
+	    /* nothing to map */
+    }
+    else if (flag & VR_REMOTE) {
 		rc = update_process_page_table(vm, range, phys, IHK_PTA_REMOTE);
 	} else if (flag & VR_IO_NOCACHE) {
 		rc = update_process_page_table(vm, range, phys, PTATTR_UNCACHABLE);