[PATCH V3 XRT Alveo Infrastructure 3/8] of: create empty of root
From: Lizhi Hou
Date: Fri Dec 03 2021 - 19:41:08 EST
When OF_FLATTREE is selected and there is not a device tree, create an
empty device tree root node. of/unittest.c code is referenced.
Signed-off-by: Sonal Santan <sonal.santan@xxxxxxxxxx>
Signed-off-by: Max Zhen <max.zhen@xxxxxxxxxx>
Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxxxxx>
---
drivers/of/Makefile | 5 +++
drivers/of/fdt.c | 61 +++++++++++++++++++++++++++++++++
drivers/of/fdt_default.dts | 5 +++
drivers/of/of_private.h | 15 ++++++++
drivers/of/unittest.c | 70 ++------------------------------------
5 files changed, 89 insertions(+), 67 deletions(-)
create mode 100644 drivers/of/fdt_default.dts
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index c13b982084a3..a2989055c578 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-y = base.o device.o platform.o property.o
+
obj-$(CONFIG_OF_KOBJ) += kobj.o
obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
obj-$(CONFIG_OF_FLATTREE) += fdt.o
@@ -20,4 +21,8 @@ obj-y += kexec.o
endif
endif
+ifndef CONFIG_OF_UNITTEST
+obj-$(CONFIG_OF_FLATTREE) += fdt_default.dtb.o
+endif
+
obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 4546572af24b..0b3577f08e1d 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -466,6 +466,67 @@ void *of_fdt_unflatten_tree(const unsigned long *blob,
}
EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
+static int __init of_fdt_root_init(void)
+{
+ struct device_node *dt = NULL, *np;
+ void *fdt, *fdt_aligned;
+ int size, rc;
+
+#if !defined(CONFIG_OF_UNITTEST)
+ if (of_root)
+ return 0;
+#endif
+ size = __dtb_fdt_default_end - __dtb_fdt_default_begin;
+
+ fdt = kmalloc(size + FDT_ALIGN_SIZE, GFP_KERNEL);
+ if (!fdt)
+ return -ENOMEM;
+
+ fdt_aligned = PTR_ALIGN(fdt, FDT_ALIGN_SIZE);
+ memcpy(fdt_aligned, __dtb_fdt_default_begin, size);
+
+ if (!of_fdt_unflatten_tree((const unsigned long *)fdt_aligned,
+ NULL, &dt)) {
+ pr_warn("%s: unflatten default tree failed\n", __func__);
+ kfree(fdt);
+ return -ENODATA;
+ }
+ if (!dt) {
+ pr_warn("%s: empty default tree\n", __func__);
+ kfree(fdt);
+ return -ENODATA;
+ }
+
+ /*
+ * This lock normally encloses of_resolve_phandles()
+ */
+ of_overlay_mutex_lock();
+
+ rc = of_resolve_phandles(dt);
+ if (rc) {
+ pr_err("%s: Failed to resolve phandles (rc=%i)\n", __func__, rc);
+ of_overlay_mutex_unlock();
+ return -EINVAL;
+ }
+
+ if (!of_root) {
+ of_root = dt;
+ for_each_of_allnodes(np)
+ __of_attach_node_sysfs(np);
+ of_aliases = of_find_node_by_path("/aliases");
+ of_chosen = of_find_node_by_path("/chosen");
+ of_overlay_mutex_unlock();
+ return 0;
+ }
+
+ unittest_data_add(dt);
+
+ of_overlay_mutex_unlock();
+
+ return 0;
+}
+pure_initcall(of_fdt_root_init);
+
/* Everything below here references initial_boot_params directly. */
int __initdata dt_root_addr_cells;
int __initdata dt_root_size_cells;
diff --git a/drivers/of/fdt_default.dts b/drivers/of/fdt_default.dts
new file mode 100644
index 000000000000..d1f12a76dfc6
--- /dev/null
+++ b/drivers/of/fdt_default.dts
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+
+/ {
+};
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 631489f7f8c0..af74ef1185be 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -41,6 +41,21 @@ extern struct mutex of_mutex;
extern struct list_head aliases_lookup;
extern struct kset *of_kset;
+#if defined(CONFIG_OF_UNITTEST)
+extern u8 __dtb_testcases_begin[];
+extern u8 __dtb_testcases_end[];
+#define __dtb_fdt_default_begin __dtb_testcases_begin
+#define __dtb_fdt_default_end __dtb_testcases_end
+int __init unittest_data_add(struct device_node *dt);
+#else
+extern u8 __dtb_fdt_default_begin[];
+extern u8 __dtb_fdt_default_end[];
+static inline int unittest_data_add(struct device_node *dt)
+{
+ return 0;
+}
+#endif
+
#if defined(CONFIG_OF_DYNAMIC)
extern int of_property_notify(int action, struct device_node *np,
struct property *prop, struct property *old_prop);
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 8c056972a6dd..bc0b3184a6ce 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -1402,73 +1402,15 @@ static void attach_node_and_children(struct device_node *np)
* unittest_data_add - Reads, copies data from
* linked tree and attaches it to the live tree
*/
-static int __init unittest_data_add(void)
+int __init unittest_data_add(struct device_node *dt)
{
- void *unittest_data;
- void *unittest_data_align;
- struct device_node *unittest_data_node = NULL, *np;
- /*
- * __dtb_testcases_begin[] and __dtb_testcases_end[] are magically
- * created by cmd_dt_S_dtb in scripts/Makefile.lib
- */
- extern uint8_t __dtb_testcases_begin[];
- extern uint8_t __dtb_testcases_end[];
- const int size = __dtb_testcases_end - __dtb_testcases_begin;
- int rc;
- void *ret;
-
- if (!size) {
- pr_warn("%s: testcases is empty\n", __func__);
- return -ENODATA;
- }
-
- /* creating copy */
- unittest_data = kmalloc(size + FDT_ALIGN_SIZE, GFP_KERNEL);
- if (!unittest_data)
- return -ENOMEM;
-
- unittest_data_align = PTR_ALIGN(unittest_data, FDT_ALIGN_SIZE);
- memcpy(unittest_data_align, __dtb_testcases_begin, size);
-
- ret = of_fdt_unflatten_tree(unittest_data_align, NULL, &unittest_data_node);
- if (!ret) {
- pr_warn("%s: unflatten testcases tree failed\n", __func__);
- kfree(unittest_data);
- return -ENODATA;
- }
- if (!unittest_data_node) {
- pr_warn("%s: testcases tree is empty\n", __func__);
- kfree(unittest_data);
- return -ENODATA;
- }
-
- /*
- * This lock normally encloses of_resolve_phandles()
- */
- of_overlay_mutex_lock();
-
- rc = of_resolve_phandles(unittest_data_node);
- if (rc) {
- pr_err("%s: Failed to resolve phandles (rc=%i)\n", __func__, rc);
- of_overlay_mutex_unlock();
- return -EINVAL;
- }
-
- if (!of_root) {
- of_root = unittest_data_node;
- for_each_of_allnodes(np)
- __of_attach_node_sysfs(np);
- of_aliases = of_find_node_by_path("/aliases");
- of_chosen = of_find_node_by_path("/chosen");
- of_overlay_mutex_unlock();
- return 0;
- }
+ struct device_node *np;
EXPECT_BEGIN(KERN_INFO,
"Duplicate name in testcase-data, renamed to \"duplicate-name#1\"");
/* attach the sub-tree to live tree */
- np = unittest_data_node->child;
+ np = dt->child;
while (np) {
struct device_node *next = np->sibling;
@@ -1480,8 +1422,6 @@ static int __init unittest_data_add(void)
EXPECT_END(KERN_INFO,
"Duplicate name in testcase-data, renamed to \"duplicate-name#1\"");
- of_overlay_mutex_unlock();
-
return 0;
}
@@ -3258,7 +3198,6 @@ static inline __init void of_unittest_overlay_high_level(void) {}
static int __init of_unittest(void)
{
struct device_node *np;
- int res;
pr_info("start of unittest - you will see error messages\n");
@@ -3267,9 +3206,6 @@ static int __init of_unittest(void)
if (IS_ENABLED(CONFIG_UML))
unittest_unflatten_overlay_base();
- res = unittest_data_add();
- if (res)
- return res;
if (!of_aliases)
of_aliases = of_find_node_by_path("/aliases");
--
2.27.0