[PATCH v4 11/27] xen/arm: Use dt_device_match to avoid multiple if conditions

[Julien Grall <julien.grall@linaro.org>]

There is some place in Xen ARM code where multiple if conditions is used
check the presence of a node or find a node.
These pieces of code can be replace by an array and using proper device tree
helpers.

Signed-off-by: Julien Grall <julien.grall@linaro.org>

---
    Changes in v3:
        - Create a macro DT_MATCH_TIMER. Will be use later
        - Remove spurious line in the patch
    Changes in v2:
        - Move skip_match and timer_ids within the appropriate functions
---
 xen/arch/arm/domain_build.c |   11 ++++++++---
 xen/arch/arm/time.c         |    9 ++++++---
 xen/include/asm-arm/time.h  |    4 ++++
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index bde041e..8ebe1bc 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -437,15 +437,20 @@ static int map_device(struct domain *d, const struct dt_device_node *dev)
 
 static int handle_node(struct domain *d, const struct dt_device_node *np)
 {
+    static const struct dt_device_match skip_matches[] __initconst =
+    {
+        DT_MATCH_COMPATIBLE("xen,xen"),
+        DT_MATCH_TYPE("memory"),
+        DT_MATCH_PATH("/chosen"),
+        { /* sentinel */ },
+    };
     const struct dt_device_node *child;
     int res;
 
     DPRINT("handle %s\n", dt_node_full_name(np));
 
     /* Skip theses nodes and the sub-nodes */
-    if ( dt_device_is_compatible(np, "xen,xen") ||
-         dt_device_type_is_equal(np, "memory") ||
-         !strcmp("/chosen", dt_node_full_name(np)) )
+    if ( dt_match_node(skip_matches, np ) )
         return 0;
 
     if ( dt_device_used_by(np) != DOMID_XEN )
diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
index 9c176cd..eb3ad5c 100644
--- a/xen/arch/arm/time.c
+++ b/xen/arch/arm/time.c
@@ -101,14 +101,17 @@ static uint32_t calibrate_timer(void)
 /* Set up the timer on the boot CPU */
 int __init init_xen_time(void)
 {
+    static const struct dt_device_match timer_ids[] __initconst =
+    {
+        DT_MATCH_TIMER,
+        { /* sentinel */ },
+    };
     struct dt_device_node *dev;
     int res;
     unsigned int i;
     u32 rate;
 
-    dev = dt_find_compatible_node(NULL, NULL, "arm,armv7-timer");
-    if ( !dev )
-        dev = dt_find_compatible_node(NULL, NULL, "arm,armv8-timer");
+    dev = dt_find_matching_node(NULL, timer_ids);
     if ( !dev )
         panic("Unable to find a compatible timer in the device tree\n");
 
diff --git a/xen/include/asm-arm/time.h b/xen/include/asm-arm/time.h
index f7aa868..9d302d3 100644
--- a/xen/include/asm-arm/time.h
+++ b/xen/include/asm-arm/time.h
@@ -1,6 +1,10 @@
 #ifndef __ARM_TIME_H__
 #define __ARM_TIME_H__
 
+#define DT_MATCH_TIMER                      \
+    DT_MATCH_COMPATIBLE("arm,armv7-timer"), \
+    DT_MATCH_COMPATIBLE("arm,armv8-timer")
+
 typedef unsigned long cycles_t;
 
 static inline cycles_t get_cycles (void)
-- 
1.7.10.4