[PATCH 4/8] xen/arm: Warn when a device tree path will be re-used by Xen

[Julien Grall <julien.grall@citrix.com>]

Xen is using unconditionnally some device tree path to create DOM0
specific node (for instance /psci, /memory and /hypervisor).

Rather than blindly add new nodes with the same, print a warning message
on the console to let know the user that something may go wrong.

Signed-off-by: Julien Grall <julien.grall@citrix.com>
---
 xen/arch/arm/domain_build.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 651d75e..2670431 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1205,6 +1205,13 @@ static int handle_node(struct domain *d, struct kernel_info *kinfo,
         DT_MATCH_TIMER,
         { /* sentinel */ },
     };
+    static const struct dt_device_match reserved_matches[] __initconst =
+    {
+        DT_MATCH_PATH("/psci"),
+        DT_MATCH_PATH("/memory"),
+        DT_MATCH_PATH("/hypervisor"),
+        { /* sentinel */ },
+    };
     struct dt_device_node *child;
     int res;
     const char *name;
@@ -1252,6 +1259,14 @@ static int handle_node(struct domain *d, struct kernel_info *kinfo,
         return 0;
     }
 
+    /*
+     * Xen is using some path for its own purpose. Warn if a node
+     * already exists with the same path.
+     */
+    if ( dt_match_node(reserved_matches, node) )
+        printk(XENLOG_WARNING "WARNING: Path %s is reserved, skip the node\n",
+               path);
+
     res = handle_device(d, node);
     if ( res)
         return res;
-- 
2.1.4