[Skiboot] [PATCH v12 04/10] dt: Add phandle fixup helpers

[Madhavan Srinivasan]

New subtree needs would have "phandle"
already assigned to some of it's nodes.
If this new substree is attached to main dt,
without fixing the phandles, would lead to
phandle duplicate errors.

Also, new subtree could have "properties"
refering to the phandle. So these "properties"
should also get updated accordingly when fixing
the "phandle".

New helper dt_adjust_subtree_phandle() added to
core/device.c to do both. It does phandle fixup
with a single pass through the subtree.

Patch also adds test in core/test/run-device.c
to exercise dt_fixup().

Signed-off-by: Madhavan Srinivasan <maddy at linux.vnet.ibm.com>
---
 core/device.c          | 38 ++++++++++++++++++++++++++++++++++++++
 core/test/run-device.c | 35 +++++++++++++++++++++++++++++++++--
 include/device.h       |  4 ++++
 3 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/core/device.c b/core/device.c
index 7211570e1b3c..7f2c94c10386 100644
--- a/core/device.c
+++ b/core/device.c
@@ -1069,3 +1069,41 @@ bool dt_node_is_enabled(struct dt_node *node)
 
 	return p->len > 1 && p->prop[0] == 'o' && p->prop[1] == 'k';
 }
+
+/*
+ * Function to fixup the phandle in the subtree.
+ */
+void dt_adjust_subtree_phandle(struct dt_node *dev,
+			const char** (get_properties_to_fix)(struct dt_node *n))
+{
+	struct dt_node *node;
+	struct dt_property *prop;
+	u32 phandle, max_phandle = 0, import_phandle = new_phandle();
+	const char **name;
+
+	dt_for_each_node(dev, node) {
+		const char **props_to_update;
+		node->phandle += import_phandle;
+
+		/*
+		 * calculate max_phandle(new_tree), needed to update
+		 * last_phandle.
+		 */
+		if (node->phandle >= max_phandle)
+			max_phandle = node->phandle;
+
+		props_to_update = get_properties_to_fix(node);
+		if (props_to_update) {
+			for (name = props_to_update; *name != NULL; name++) {
+				prop = __dt_find_property(node, *name);
+				if (prop) {
+					phandle = dt_prop_get_u32(node, *name);
+					phandle += import_phandle;
+					memcpy((char *)&prop->prop, &phandle, prop->len);
+				}
+			}
+		}
+       }
+
+       set_last_phandle(max_phandle);
+}
diff --git a/core/test/run-device.c b/core/test/run-device.c
index 5939afc70e54..ffc8a4b9d1e1 100644
--- a/core/test/run-device.c
+++ b/core/test/run-device.c
@@ -33,6 +33,8 @@ static inline bool fake_is_rodata(const void *p)
 #include "../device.c"
 #include <assert.h>
 #include "../../test/dt_common.c"
+const char *prop_to_fix[] = {"something", NULL};
+const char **imc_prop_to_fix(struct dt_node *node);
 
 static void check_path(const struct dt_node *node, const char * expected_path)
 {
@@ -87,18 +89,29 @@ static bool is_sorted(const struct dt_node *root)
 	return true;
 }
 
+/*handler for phandle fixup test */
+const char **imc_prop_to_fix(struct dt_node *node)
+{
+	const struct dt_property *prop;
+
+	prop = dt_find_property(node, "something");
+	if (prop)
+		return prop_to_fix;
+
+	return NULL;
+}
 
 int main(void)
 {
 	struct dt_node *root, *c1, *c2, *gc1, *gc2, *gc3, *ggc1, *ggc2;
 	struct dt_node *addrs, *addr1, *addr2;
-	struct dt_node *i;
+	struct dt_node *i, *subtree, *ev1, *ut1, *ut2;
 	const struct dt_property *p;
 	struct dt_property *p2;
 	unsigned int n;
 	char *s;
 	size_t sz;
-	u32 phandle;
+	u32 phandle, ev1_ph, new_prop_ph;
 
 	root = dt_new_root("");
 	assert(!list_top(&root->properties, struct dt_property, list));
@@ -412,6 +425,24 @@ int main(void)
 
 	dt_free(root);
 
+	/* phandle fixup test */
+	subtree = dt_new_root("subtree");
+	ev1 = dt_new(subtree, "ev at 1");
+	ev1_ph = ev1->phandle;
+	dt_new(ev1,"a at 1");
+	dt_new(ev1,"a at 2");
+	dt_new(ev1,"a at 3");
+	ut1 = dt_new(subtree, "ut at 1");
+	dt_add_property(ut1, "something", (const void *)&ev1->phandle, 4);
+	ut2 = dt_new(subtree, "ut at 2");
+	dt_add_property(ut2, "something", (const void *)&ev1->phandle, 4);
+
+	dt_adjust_subtree_phandle(subtree, imc_prop_to_fix);
+	assert(!(ev1->phandle == ev1_ph));
+	new_prop_ph = dt_prop_get_u32(ut1, "something");
+	assert(!(new_prop_ph == ev1_ph));
+	new_prop_ph = dt_prop_get_u32(ut2, "something");
+	assert(!(new_prop_ph == ev1_ph));
 	return 0;
 }
 
diff --git a/include/device.h b/include/device.h
index c51b3eea298e..1e5875dca584 100644
--- a/include/device.h
+++ b/include/device.h
@@ -268,4 +268,8 @@ struct dt_node *__dt_find_by_name_addr(struct dt_node *parent, const char *name,
 struct dt_node *dt_find_by_name_addr(struct dt_node *parent, const char *name,
 				uint64_t addr);
 
+/* phandle fixup helper */
+void dt_adjust_subtree_phandle(struct dt_node *subtree,
+				const char** (get_properties_to_fix)(struct dt_node *n));
+
 #endif /* __DEVICE_H */
-- 
2.7.4