[PATCH v2] Adding selftest testdata dynamically into live tree

[Gaurav Minocha <gaurav.minocha.os-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

This patch attaches selftest's device tree data (required by /drivers/of/selftest.c)
dynamically into live device tree. First, it links selftest device tree data into the
kernel image and then iterates over all the nodes and attaches them into the live tree.
Once the testcases are complete, it removes the data attached.

This patch will remove the manual process of addition and removal of selftest device
tree data into the machine's dts file. Also, it can be build as a loadable kernel
module by setting the config symbol OF_SELFTEST=m.

Tested successfully with current selftest's testcases.

Signed-off-by: Gaurav Minocha <gaurav.minocha.os-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 arch/arm/boot/dts/versatile-pb.dts      |    2 -
 drivers/of/Kconfig                      |    3 +-
 drivers/of/Makefile                     |    3 +-
 drivers/of/base.c                       |    5 ++
 drivers/of/platform.c                   |    1 +
 drivers/of/selftest.c                   |  135 +++++++++++++++++++++++++++++++
 drivers/of/testcase-data/testcases.dts  |    5 ++
 drivers/of/testcase-data/testcases.dtsi |    4 -
 8 files changed, 150 insertions(+), 8 deletions(-)
 create mode 100644 drivers/of/testcase-data/testcases.dts
 delete mode 100644 drivers/of/testcase-data/testcases.dtsi

diff --git a/arch/arm/boot/dts/versatile-pb.dts b/arch/arm/boot/dts/versatile-pb.dts
index 65f6577..8d39677 100644
--- a/arch/arm/boot/dts/versatile-pb.dts
+++ b/arch/arm/boot/dts/versatile-pb.dts
@@ -46,5 +46,3 @@
 		};
 	};
 };
-
-#include <testcases.dtsi>
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 2dcb054..4e4f6f3 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -8,8 +8,9 @@ menu "Device Tree and Open Firmware support"
 	depends on OF
 
 config OF_SELFTEST
-	bool "Device Tree Runtime self tests"
+	tristate "Device Tree Runtime self tests"
 	depends on OF_IRQ
+	select OF_DYNAMIC
 	help
 	  This option builds in test cases for the device tree infrastructure
 	  that are executed once at boot time, and the results dumped to the
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 099b1fb..b9e753b 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -5,7 +5,8 @@ obj-$(CONFIG_OF_PROMTREE) += pdt.o
 obj-$(CONFIG_OF_ADDRESS)  += address.o
 obj-$(CONFIG_OF_IRQ)    += irq.o
 obj-$(CONFIG_OF_NET)	+= of_net.o
-obj-$(CONFIG_OF_SELFTEST) += selftest.o
+obj-$(CONFIG_OF_SELFTEST) += of_selftest.o
+of_selftest-objs := selftest.o testcase-data/testcases.dtb.o
 obj-$(CONFIG_OF_MDIO)	+= of_mdio.o
 obj-$(CONFIG_OF_PCI)	+= of_pci.o
 obj-$(CONFIG_OF_PCI_IRQ)  += of_pci_irq.o
diff --git a/drivers/of/base.c b/drivers/of/base.c
index b986480..aaf7219 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1814,6 +1814,7 @@ int of_add_property(struct device_node *np, struct property *prop)
 
 	return rc;
 }
+EXPORT_SYMBOL_GPL(of_add_property);
 
 /**
  * of_remove_property - Remove a property from a node.
@@ -1860,6 +1861,7 @@ int of_remove_property(struct device_node *np, struct property *prop)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(of_remove_property);
 
 /*
  * of_update_property - Update a property in a node, if the property does
@@ -1915,6 +1917,7 @@ int of_update_property(struct device_node *np, struct property *newprop)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(of_update_property);
 
 #if defined(CONFIG_OF_DYNAMIC)
 /*
@@ -1970,6 +1973,7 @@ int of_attach_node(struct device_node *np)
 	of_node_add(np);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(of_attach_node);
 
 /**
  * of_detach_node - "Unplug" a node from the device tree.
@@ -2029,6 +2033,7 @@ int of_detach_node(struct device_node *np)
 	of_node_remove(np);
 	return rc;
 }
+EXPORT_SYMBOL_GPL(of_detach_node);
 #endif /* defined(CONFIG_OF_DYNAMIC) */
 
 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 500436f..b7a82d6 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -30,6 +30,7 @@ const struct of_device_id of_default_bus_match_table[] = {
 #endif /* CONFIG_ARM_AMBA */
 	{} /* Empty terminated list */
 };
+EXPORT_SYMBOL(of_default_bus_match_table);
 
 static int of_dev_node_match(struct device *dev, void *data)
 {
diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c
index 077314e..f40a1e6 100644
--- a/drivers/of/selftest.c
+++ b/drivers/of/selftest.c
@@ -9,6 +9,7 @@
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_fdt.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/list.h>
@@ -21,6 +22,10 @@ static struct selftest_results {
 	int failed;
 } selftest_results;
 
+static void *selftest_data;
+static struct device_node *selftest_data_node;
+static struct device_node *remove_data_node;
+
 #define selftest(result, fmt, ...) { \
 	if (!(result)) { \
 		selftest_results.failed++; \
@@ -517,9 +522,134 @@ static void __init of_selftest_platform_populate(void)
 	}
 }
 
+/**
+ *	update_node_properties - adds the properties
+ *	of np into dup node (present in live tree) and
+ *	updates parent of children of np to dup.
+ *
+ *	@np:	node already present in live tree
+ *	@dup:	node present in live tree to be updated
+ */
+static void update_node_properties(struct device_node *np,
+					struct device_node *dup)
+{
+	struct property *prop;
+	struct device_node *child;
+
+	for_each_property_of_node(np, prop)
+		of_add_property(dup, prop);
+
+	for_each_child_of_node(np, child)
+		child->parent = dup;
+}
+
+/**
+ *	attach_node_and_children - attaches nodes
+ *	and its children to live tree
+ *
+ *	@np:	Node to attach to live tree
+ */
+static int attach_node_and_children(struct device_node *np)
+{
+	struct device_node *next, *root = np, *dup;
+
+	if (!np) {
+		pr_warn("%s: No tree to attach; not running tests\n",
+			__func__);
+		return -ENODATA;
+	}
+
+
+	/* skip root node */
+	np = np->child;
+
+	while (np) {
+		next = np->allnext;
+		dup = of_find_node_by_path(np->full_name);
+		if (dup)
+			update_node_properties(np, dup);
+		else {
+			np->child = NULL;
+			if (np->parent == root)
+				np->parent = of_allnodes;
+			of_attach_node(np);
+		}
+		np = next;
+	}
+
+	return 0;
+}
+
+/**
+ *	selftest_data_init - Reads, copies data from
+ *	linked tree and attaches it to the live tree
+ */
+static int __init selftest_data_init(void)
+{
+	int size;
+	extern uint8_t __dtb_testcases_begin[];
+	extern uint8_t __dtb_testcases_end[];
+
+	selftest_data = (void *)__dtb_testcases_begin;
+
+	if (!selftest_data) {
+		pr_warn("%s: No testcase data to attach; not running tests\n",
+			__func__);
+		return -ENODATA;
+	}
+
+	size = __dtb_testcases_end - __dtb_testcases_begin;
+
+	/* creating copy */
+	selftest_data = kmemdup(selftest_data, size, GFP_KERNEL);
+
+	if (!selftest_data) {
+		pr_warn("%s: Failed to allocate memory for selftest_data; "
+			"not running tests\n", __func__);
+		return -ENOMEM;
+	}
+	of_fdt_unflatten_tree((unsigned long *)selftest_data,
+						&selftest_data_node);
+	/* store a copy for removal */
+	of_fdt_unflatten_tree((unsigned long *)selftest_data,
+						&remove_data_node);
+
+
+	/* attach the sub-tree to live tree */
+	return attach_node_and_children(selftest_data_node);
+}
+
+static void selftest_data_remove(struct device_node *np)
+{
+	struct property *prop;
+
+	if (!np) {
+		pr_info("No testcase data in device tree; unable to remove data\n");
+		return;
+	}
+	if (np->allnext)
+		selftest_data_remove(np->allnext);
+
+	np = of_find_node_by_path(np->full_name);
+
+	if (strcmp(np->full_name, "/aliases") == 0) {
+		for_each_property_of_node(np, prop) {
+			if (strcmp(prop->name, "testcase-alias") == 0)
+				of_remove_property(np, prop);
+		}
+	} else
+		of_detach_node(np);
+}
+
 static int __init of_selftest(void)
 {
 	struct device_node *np;
+	int res;
+
+	/* adding data for selftest */
+	res = selftest_data_init();
+	if (res)
+		return res;
 
 	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
 	if (!np) {
@@ -539,6 +669,11 @@ static int __init of_selftest(void)
 	of_selftest_platform_populate();
 	pr_info("end of selftest - %i passed, %i failed\n",
 		selftest_results.passed, selftest_results.failed);
+
+	/* removing data for selftest */
+	selftest_data_remove(remove_data_node);
+
 	return 0;
 }
 late_initcall(of_selftest);
+MODULE_LICENSE("GPL");
diff --git a/drivers/of/testcase-data/testcases.dts b/drivers/of/testcase-data/testcases.dts
new file mode 100644
index 0000000..8e7568e
--- /dev/null
+++ b/drivers/of/testcase-data/testcases.dts
@@ -0,0 +1,5 @@
+/dts-v1/;
+#include "tests-phandle.dtsi"
+#include "tests-interrupts.dtsi"
+#include "tests-match.dtsi"
+#include "tests-platform.dtsi"
diff --git a/drivers/of/testcase-data/testcases.dtsi b/drivers/of/testcase-data/testcases.dtsi
deleted file mode 100644
index 6d8d980a..0000000
--- a/drivers/of/testcase-data/testcases.dtsi
+++ /dev/null
@@ -1,4 +0,0 @@
-#include "tests-phandle.dtsi"
-#include "tests-interrupts.dtsi"
-#include "tests-match.dtsi"
-#include "tests-platform.dtsi"
-- 
1.7.9.5

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