The common/device-tree/device-tree.c contains generic unflatten DT helpers API,
while dt_find_node_by_gpath() is specific for domctl (iommu) processing.
We move this function into drivers\passthrough\device_tree.c and make it
static, as it is used only there now.

Suggested-by: Grygorii Strashko <grygorii_strashko@epam.com>
Signed-off-by: Penny Zheng <penny.zheng@amd.com>
---
v4 -> v5:
- new commit
---
 xen/common/device-tree/device-tree.c  | 16 ---------------
 xen/drivers/passthrough/device_tree.c | 28 +++++++++++++++++++++++++++
 xen/include/xen/device_tree.h         | 13 -------------
 3 files changed, 28 insertions(+), 29 deletions(-)

diff --git a/xen/common/device-tree/device-tree.c b/xen/common/device-tree/device-tree.c
index 0b5375f151..d6cf417e94 100644
--- a/xen/common/device-tree/device-tree.c
+++ b/xen/common/device-tree/device-tree.c
@@ -371,22 +371,6 @@ struct dt_device_node *dt_find_node_by_path_from(struct dt_device_node *from,
     return np;
 }
 
-int dt_find_node_by_gpath(XEN_GUEST_HANDLE(char) u_path, uint32_t u_plen,
-                          struct dt_device_node **node)
-{
-    char *path;
-
-    path = safe_copy_string_from_guest(u_path, u_plen, PAGE_SIZE);
-    if ( IS_ERR(path) )
-        return PTR_ERR(path);
-
-    *node = dt_find_node_by_path(path);
-
-    xfree(path);
-
-    return (*node == NULL) ? -ESRCH : 0;
-}
-
 struct dt_device_node *dt_find_node_by_alias(const char *alias)
 {
     const struct dt_alias_prop *app;
diff --git a/xen/drivers/passthrough/device_tree.c b/xen/drivers/passthrough/device_tree.c
index f5850a2607..eb0c233977 100644
--- a/xen/drivers/passthrough/device_tree.c
+++ b/xen/drivers/passthrough/device_tree.c
@@ -16,6 +16,7 @@
  */
 
 #include <xen/device_tree.h>
+#include <xen/err.h>
 #include <xen/guest_access.h>
 #include <xen/iommu.h>
 #include <xen/lib.h>
@@ -318,6 +319,33 @@ int iommu_add_dt_device(struct dt_device_node *np)
     return rc;
 }
 
+/*
+ * dt_find_node_by_gpath - Same as dt_find_node_by_path but retrieve the
+ * path from the guest
+ *
+ * @u_path: Xen Guest handle to the buffer containing the path
+ * @u_plen: Length of the buffer
+ * @node: TODO
+ *
+ * Return 0 if succeed otherwise -errno
+ */
+static int dt_find_node_by_gpath(XEN_GUEST_HANDLE(char) u_path,
+                                 uint32_t u_plen,
+                                 struct dt_device_node **node)
+{
+    char *path;
+
+    path = safe_copy_string_from_guest(u_path, u_plen, PAGE_SIZE);
+    if ( IS_ERR(path) )
+        return PTR_ERR(path);
+
+    *node = dt_find_node_by_path(path);
+
+    xfree(path);
+
+    return (*node == NULL) ? -ESRCH : 0;
+}
+
 int iommu_do_dt_domctl(struct xen_domctl *domctl, struct domain *d,
                        XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
 {
diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
index 06d7643622..241f269b57 100644
--- a/xen/include/xen/device_tree.h
+++ b/xen/include/xen/device_tree.h
@@ -550,19 +550,6 @@ static inline struct dt_device_node *dt_find_node_by_path(const char *path)
     return dt_find_node_by_path_from(dt_host, path);
 }
 
-/**
- * dt_find_node_by_gpath - Same as dt_find_node_by_path but retrieve the
- * path from the guest
- *
- * @u_path: Xen Guest handle to the buffer containing the path
- * @u_plen: Length of the buffer
- * @node: TODO
- *
- * Return 0 if succeed otherwise -errno
- */
-int dt_find_node_by_gpath(XEN_GUEST_HANDLE(char) u_path, uint32_t u_plen,
-                          struct dt_device_node **node);
-
 /**
  * dt_get_parent - Get a node's parent if any
  * @node: Node to get parent
-- 
2.34.1